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Sample records for cexzr1-xo2 nanoparticles synthesized

  1. Method of synthesizing tungsten nanoparticles

    Science.gov (United States)

    Thoma, Steven G; Anderson, Travis M

    2013-02-12

    A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

  2. Biogenic synthesized nanoparticles and their applications

    Science.gov (United States)

    Singh, Abhijeet; Sharma, Madan Mohan

    2016-05-01

    In the present scenario, there are growing concerns over the potential impacts of bioengineered nanoparticles in the health sector. However, our understanding of how bioengineered nanoparticles may affect organisms within natural ecosystems, lags far behind our rapidly increasing ability to engineer novel nanoparticles. To date, research on the biological impacts of bioengineered nanoparticles has primarily consisted of controlled lab studies of model organisms with single species in culture media. Here, we described a cost effective and environment friendly technique for green synthesis of silver nanoparticles. Silver nanoparticles were successfully synthesized from 1 mM AgNO3 via a green synthesis process using leaf extract as reducing as well as capping agent. Nanoparticles were characterized with the help of UV-vis absorption spectroscopy, X-ray diffraction and TEM analysis which revealed the size of nanoparticles of 30-40 nm size. Further the nanoparticles synthesized by green route are found highly toxic against pathogenic bacteria and plant pathogenic fungi viz. Escherichia coli, Pseudomonas syringae and Sclerotiniasclerotiorum. The most important outcome of this work will be the development of value-added products and protection of human health from pathogens viz., bacteria, virus, fungi etc.

  3. Radiolytic syntheses of nanoparticles in supramolecular assemblies.

    Science.gov (United States)

    Chen, Qingde; Shen, Xinghai; Gao, Hongcheng

    2010-08-11

    Ionizing radiation is a powerful method in the syntheses of nanoparticles (NPs). The application of ionizing radiation in supramolecular assemblies can afford us more unique conditions to control the composition and morphology of the NPs. So far, most work focused on water-in-oil (W/O) microemulsions or reversed micelles. In this supramolecular organization, it has been proved that the effects of many conditions on the yield of e(aq)(-) play a key role, remarkably different from the mechanism in routine chemical method. Besides, some supramolecular assemblies of cyclodextrins and ionic liquids have been used in the syntheses of NPs by ionizing radiation, and many novel and interesting phenomena appeared. This review is intended to underline the three significant aspects of the radiolytic syntheses of NPs in supramolecular assemblies. PMID:20653087

  4. Tailored super magnetic nanoparticles synthesized via template free hydrothermal technique

    Science.gov (United States)

    Attallah, Olivia A.; Girgis, E.; Abdel-Mottaleb, Mohamed M. S. A.

    2016-01-01

    Magnetite nanoparticles of controlled shape and dimensions were synthesized using a modified hydrothermal technique. The influence of different synthesis conditions on the shape, size (length and diameter), structure and magnetic properties of the prepared nanoparticles is presented. The mineral phases, the morphologies, size distribution of the resulting magnetic nanoparticles and their magnetic properties were characterized using different characterization methods. We designed magnetite nanoparticles with different morphologies (nanospheres, nanorods, nanocubes and hexagons) and with improved saturation magnetization reaching 90 emu/g.

  5. Monodisperse Silver Nanoparticles Synthesized by a Microwave-Assisted Method

    Institute of Scientific and Technical Information of China (English)

    ZHU Shao-Peng; TANG Shao-Chun; MENG Xiang-Kang

    2009-01-01

    Silver nanoparticles with an average size of about 2Onto are synthesized in a colloidal solution with the aid of microwave irradiation. Neither additional reductant nor stabilizer is required in this microwave-assisted method.The color of the colloidal solution is found to be dark green, different from the characteristic yellow of silver colloidal solutions. The silver nanoparticles in the colloidal solution have a narrow size distribution and large yield quantity. UV-visible absorption spectroscopy analysis reveals that the as-synthesized monodisperse silver nanoparticles have exceptional optical properties. Raman spectroscopy measurements demonstrate that these silver nanoparticles exhibit a notable surface-enhanced Raman scattering ability.

  6. Electrospray deposition of isolated chemically synthesized magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, Pierre; Meffre, Anca; Lacroix, Lise-Marie; Ugnati, Damien [Université de Toulouse (France); INSA, UPS, CNRS, Laboratoire de Physique et Chimie des Nano-objets (LPCNO) (France); Ondarçuhu, Thierry [Centre d’Elaboration de Matériaux et d’Etudes Structurales (CEMES-CNRS) (France); Respaud, Marc; Lassagne, Benjamin, E-mail: lassagne@insa-toulouse.fr [Université de Toulouse (France); INSA, UPS, CNRS, Laboratoire de Physique et Chimie des Nano-objets (LPCNO) (France)

    2016-01-15

    The deposition of isolated magnetic nanoparticles onto a substrate was performed using electrohydrodynamic spraying. Two kinds of nanoparticles were sprayed, 11 nm CoFe carbide nanospheres and 10.5 nm Fe nanocubes. By studying carefully the evolution of the sprayed charged droplets and the mechanism of nanoparticle dispersion in them, we could optimize the nanoparticle concentration within the initial nanoparticle solution (i) to reduce the magnetic interaction and therefore prevent agglomeration and (ii) to obtain in a relatively short period (1 h) a deposit of isolated magnetic nanoparticles with a density of up to 400 nanoparticles per µm{sup 2}. These results open great perspectives for magnetic measurements on single objects using advanced magnetometry techniques as long as spintronics applications based on single chemically synthesized magnetic nanoparticles.

  7. Monodispersive CoPt Nanoparticles Synthesized Using Chemical Reduction Method

    Institute of Scientific and Technical Information of China (English)

    SHEN Cheng-Min; HUI Chao; YANG Tian-Zhong; XIAO Cong-Wen; CHEN Shu-Tang; DING Hao; GAO Hong-Jun

    2008-01-01

    @@ Monodispersive CoPt nanoparticles in sizes of about 2.2 nm are synthesized by superhydride reduction of CoCl2 and PtCl2 in diphenyl ether. The as-prepared nanoparticles show a chemically disordered A1 structure and are superparamagnetic. Thermal annealing transforms the A1 structure into chemically ordered L1o structure and the particles are ferromagnetic at room temperature.

  8. Antibacterial screening of silver nanoparticles synthesized by marine micro algae

    Institute of Scientific and Technical Information of China (English)

    D Devina Merin; S Prakash; B Valentine Bhimba

    2010-01-01

    Objective:To explore the biosynthesis of silver nanoparticles synthesized by marine microalgae. Methods: Marine microalgae was collected from Central Marine Fisheries Research Institute (CMFRI, tuticorin) and cultured in the lab. Silver nanoparticles synthesis were observed in normal and microwave irradiated microalgae and screened against human pathogens for the presence of antimicrobials.Results: The presence of silver nanoparticle was confirmed by UV-Visible spectroscopy at420 nm by the presence of plasmon peak. Further confirmation was done by scanning electron microscope(SEM).Conclusions: These results not only provide a base for further research but are useful for drug development in the present and future.

  9. SILVER NANOPARTICLES SYNTHESIZED BY THE AZERBAIJANIAN ENVIRONMENTAL ISOLATES ASPERGILLUS NIGER

    Directory of Open Access Journals (Sweden)

    Kh. G. Ganbarov

    2014-10-01

    Full Text Available The synthesis of nanoparticles by microorganisms is environmentally safe method. The silver nanoparticles produced by fungi is complex material having different size, shape and other properties depending on the producer. İt is necessary to study new microbial strains to synthesize silver nanoparticles with important properties. The synthesis of different stable silver nanoparticles by the mold fungi was investigated in this work. To achieve this goal different strains (isolates of Aspergillus niger were used. The most intensive formation of nanoparticles was observed in strains Aspergillus niger BDU-A4, BDU-K8, BDU-UB1 and BDU-UB5.While examining nanoparticles the following analysis methods were used: UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM and Energy Dispersive Spectroscopy. Electron microscopic examination showed that the shape, size and nature of nanoparticles’ clusters were dependent on fungal strains. The shape of nanoparticles is usually circular but it may be oval like in case of nanoclusters consisting of a few spherical nanoparticles. Their size varies from 20 to 100 nm.The formation of free ellipsoidal shape nanoparticles was observed at strain of Aspergillus niger BDU-K8, that varies in the range 62,9 - 68,4 nm.

  10. Magnetic Properties of Chemically Synthesized FePt Nanoparticles

    Science.gov (United States)

    Harrell, J. W.

    2005-03-01

    Chemically synthesized FePt nanoparticles have attracted considerable attention in recent years because of their potential use in ultra-high density magnetic recording media. In the original procedure described by Sun et al., the as-synthesized nanoparticles have the fcc phase and must be thermally annealed to achieve the high-anisotropy L10 phase [1]. We have been addressing some of the materials problems associated with obtaining the L10 phase. These include lowering the ordering temperature, reducing sintering during annealing, orienting the easy axes, and understanding the size effect on chemical ordering. Additive Au and Ag significantly lower the ordering temperature, while additive Cr and Cu increase the ordering temperature; however, the onset of ordering is correlated with sintered grain growth. Sintering can be reduced by encapsulating the nanoparticles with a shell such as silicon oxide or copper. Easy-axis orientation has been achieved using L10 FePt nanoparticles that were directly synthesized using a high-temperature solvent [2]. The nanoparticles were dispersed in a PVC binder and oriented by drying the dispersion in a magnetic field. [1] S. Sun et al., Science 287, 1989 (2000). [2] S. Kang et al., Appl Phys. Lett. (in press).

  11. ARSENIC REMOVAL USING SOL-GEL SYNTHESIZED TITANIUM DIOXIDE NANOPARTICLES

    Science.gov (United States)

    In this study, the effectiveness of TiO2 nanoparticles in arsenic adsorption was examined. TiO2 particles (LS) were synthesized via sol-gel techniques and characterized for their crystallinity, surface area and pore volume. Batch adsorption studies were perf...

  12. Copper nanoparticles synthesized in polymers by ion implantation

    DEFF Research Database (Denmark)

    Popok, Vladimir; Nuzhdin, Vladimir; Valeev, Valerij;

    2015-01-01

    as optical transmission spectroscopy. It is found that copper nanoparticles nucleation and growth are strongly fluence dependent as well as they are affected by the polymer properties, in particular, by radiation stability yielding different nanostructures for the implanted PI and PMMA. Shallow synthesized...

  13. Evaluation of cytotoxicity of polypyrrole nanoparticles synthesized by oxidative polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vaitkuviene, Aida [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Kaseta, Vytautas [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Voronovic, Jaroslav [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Ramanauskaite, Giedre; Biziuleviciene, Gene [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Ramanaviciene, Almira [NanoTechnas–Center of Nanotechnology and Material Science at Department of Analytical and Environmental Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, 03225 Vilnius (Lithuania); Ramanavicius, Arunas, E-mail: Arunas.Ramanavicius@chf.vu.lt [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Laboratory of BioNanoTechnology, Department of Materials Science and Electronics, Institute of Semiconductor Physics, State Scientific Research Institute Centre for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius (Lithuania)

    2013-04-15

    Highlights: ► Polypyrrole nanoparticles synthesized by environmentally friendly polymerization at high concentrations are cytotoxic. ► Primary mouse embryonic fibroblast, mouse hepatoma and human T lymphocyte Jurkat cell lines were treated by Ppy nanoparticles. ► Polypyrrole nanoparticles at high concentrations inhibit cell proliferation. -- Abstract: Polypyrrole (Ppy) is known as biocompatible material, which is used in some diverse biomedical applications and seeming to be a very promising for advanced biotechnological applications. In order to increase our understanding about biocompatibility of Ppy, in this study pure Ppy nanoparticles (Ppy-NPs) of fixed size and morphology were prepared by one-step oxidative polymerization and their cyto-compatibility was evaluated. The impact of different concentration of Ppy nanoparticles on primary mouse embryonic fibroblasts (MEF), mouse hepatoma cell line (MH-22A), and human T lymphocyte Jurkat cell line was investigated. Cell morphology, viability/proliferation after the treatment by Ppy nanoparticles was evaluated. Obtained results showed that Ppy nanoparticles at low concentrations are biocompatible, while at high concentrations they became cytotoxic for Jurkat, MEF and MH-22A cells, and it was found that cytotoxic effect is dose-dependent.

  14. Evaluation of Biological Activities of Chemically Synthesized Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ashraf A. Mostafa

    2015-01-01

    Full Text Available Silver nanoparticles were synthesized by the earlier reported methods. The synthesized nanoparticles were characterized using ultraviolet-visible spectrophotometry (UV/Vis, transmission electron microscopy (TEM, energy dispersive X-ray spectroscopy (EDX, and X-ray powder diffraction (XRD. The synthesized materials were also evaluated for their antibacterial activity against Gram positive and Gram negative bacterial strains. TEM micrograph showed the spherical morphology of AgNPs with size range of 40–60 nm. The synthesized nanoparticles showed a strong antimicrobial activity and their effect depends upon bacterial strain as AgNPs exhibited greater inhibition zone for Pseudomonas aeruginosa (19.1 mm followed by Staphylococcus aureus (14.8 mm and S. pyogenes (13.6 mm while the least activity was observed for Salmonella typhi (12.5 mm at concentration of 5 µg/disc. The minimum inhibitory concentration (MIC of AgNPs against S. aureus was 2.5 µg/disc and less than 2.5 µg/disc for P. aeruginosa. These results suggested that AgNPs can be used as an effective antiseptic agent for infectious control in medical field.

  15. Antibacterial activity of silver nanoparticles synthesized from serine

    Energy Technology Data Exchange (ETDEWEB)

    Jayaprakash, N. [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); SRM Valliammai Engineering College, Department of Chemistry, Chennai 603 203 (India); Judith Vijaya, J., E-mail: jjvijayaloyola@yahoo.co.in [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); John Kennedy, L. [Materials Division, School of Advanced Sciences, VIT University, Chennai Campus, Chennai 600 048 (India); Priadharsini, K.; Palani, P. [Department of Center for Advanced Study in Botany, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2015-04-01

    Silver nanoparticles (Ag NPs) were synthesized by a simple microwave irradiation method using polyvinyl pyrrolidone (PVP) as a capping agent and serine as a reducing agent. UV–Visible spectra were used to confirm the formation of Ag NPs by observing the surface plasmon resonance (SPR) band at 443 nm. The emission spectrum of Ag NPs showed an emission band at 484 nm. In the presence of microwave radiation, serine acts as a reducing agent, which was confirmed by Fourier transformed infrared (FT-IR) spectrum. High-resolution transmission electron microscopy (HR-TEM) and high-resolution scanning electron microscopy (HR-SEM) were used to investigate the morphology of the synthesized sample. These images showed the sphere-like morphology. The elemental composition of the sample was determined by the energy dispersive X-ray analysis (EDX). Selected area electron diffraction (SAED) was used to find the crystalline nature of the Ag NPs. The electrochemical behavior of the synthesized Ag NPs was analyzed by the cyclic voltammetry (CV). Antibacterial experiments showed that the prepared Ag NPs showed relatively similar antibacterial activities, when compared with AgNO{sub 3} against Gram-positive and Gram-negative bacteria. - Highlights: • Microwave irradiation method is used to synthesize silver nanoparticles. • Highly stable silver nanoparticles are produced from serine. • A detailed study of antibacterial activities is discussed. • Formation mechanism of silver microspheres has been proposed.

  16. Oriented attachment explains cobalt ferrite nanoparticle growth in bioinspired syntheses.

    Science.gov (United States)

    Wolff, Annalena; Hetaba, Walid; Wißbrock, Marco; Löffler, Stefan; Mill, Nadine; Eckstädt, Katrin; Dreyer, Axel; Ennen, Inga; Sewald, Norbert; Schattschneider, Peter; Hütten, Andreas

    2014-01-01

    Oriented attachment has created a great debate about the description of crystal growth throughout the last decade. This aggregation-based model has successfully described biomineralization processes as well as forms of inorganic crystal growth, which could not be explained by classical crystal growth theory. Understanding the nanoparticle growth is essential since physical properties, such as the magnetic behavior, are highly dependent on the microstructure, morphology and composition of the inorganic crystals. In this work, the underlying nanoparticle growth of cobalt ferrite nanoparticles in a bioinspired synthesis was studied. Bioinspired syntheses have sparked great interest in recent years due to their ability to influence and alter inorganic crystal growth and therefore tailor properties of nanoparticles. In this synthesis, a short synthetic version of the protein MMS6, involved in nanoparticle formation within magnetotactic bacteria, was used to alter the growth of cobalt ferrite. We demonstrate that the bioinspired nanoparticle growth can be described by the oriented attachment model. The intermediate stages proposed in the theoretical model, including primary-building-block-like substructures as well as mesocrystal-like structures, were observed in HRTEM measurements. These structures display regions of substantial orientation and possess the same shape and size as the resulting discs. An increase in orientation with time was observed in electron diffraction measurements. The change of particle diameter with time agrees with the recently proposed kinetic model for oriented attachment. PMID:24605288

  17. Oriented attachment explains cobalt ferrite nanoparticle growth in bioinspired syntheses

    Directory of Open Access Journals (Sweden)

    Annalena Wolff

    2014-02-01

    Full Text Available Oriented attachment has created a great debate about the description of crystal growth throughout the last decade. This aggregation-based model has successfully described biomineralization processes as well as forms of inorganic crystal growth, which could not be explained by classical crystal growth theory. Understanding the nanoparticle growth is essential since physical properties, such as the magnetic behavior, are highly dependent on the microstructure, morphology and composition of the inorganic crystals. In this work, the underlying nanoparticle growth of cobalt ferrite nanoparticles in a bioinspired synthesis was studied. Bioinspired syntheses have sparked great interest in recent years due to their ability to influence and alter inorganic crystal growth and therefore tailor properties of nanoparticles. In this synthesis, a short synthetic version of the protein MMS6, involved in nanoparticle formation within magnetotactic bacteria, was used to alter the growth of cobalt ferrite. We demonstrate that the bioinspired nanoparticle growth can be described by the oriented attachment model. The intermediate stages proposed in the theoretical model, including primary-building-block-like substructures as well as mesocrystal-like structures, were observed in HRTEM measurements. These structures display regions of substantial orientation and possess the same shape and size as the resulting discs. An increase in orientation with time was observed in electron diffraction measurements. The change of particle diameter with time agrees with the recently proposed kinetic model for oriented attachment.

  18. Catalytically and biologically active silver nanoparticles synthesized using essential oil

    Science.gov (United States)

    Vilas, Vidya; Philip, Daizy; Mathew, Joseph

    2014-11-01

    There are numerous reports on phytosynthesis of silver nanoparticles and various phytochemicals are involved in the reduction and stabilization. Pure explicit phytosynthetic protocol for catalytically and biologically active silver nanoparticles is of importance as it is an environmentally benign green method. This paper reports the use of essential oil of Myristica fragrans enriched in terpenes and phenyl propenes in the reduction and stabilization. FTIR spectra of the essential oil and the synthesized biogenic silver nanoparticles are in accordance with the GC-MS spectral analysis reports. Nanosilver is initially characterized by an intense SPR band around 420 nm, followed by XRD and TEM analysis revealing the formation of 12-26 nm sized, highly pure, crystalline silver nanoparticles. Excellent catalytic and bioactive potential of the silver nanoparticles is due to the surface modification. The chemocatalytic potential of nanosilver is exhibited by the rapid reduction of the organic pollutant, para nitro phenol and by the degradation of the thiazine dye, methylene blue. Significant antibacterial activity of the silver colloid against Gram positive, Staphylococcus aureus (inhibition zone - 12 mm) and Gram negative, Escherichia coli (inhibition zone - 14 mm) is demonstrated by Agar-well diffusion method. Strong antioxidant activity of the biogenic silver nanoparticles is depicted through NO scavenging, hydrogen peroxide scavenging, reducing power, DPPH and total antioxidant activity assays.

  19. Characterization of chemically synthesized CdS nanoparticles

    Indian Academy of Sciences (India)

    Rajeev R Prabhu; M Abdul Khadar

    2005-11-01

    II–VI semiconductor nanoparticles are presently of great interest for their practical applications such as zero-dimensional quantum confined materials and for their applications in optoelectronics and photonics. The optical properties get modified dramatically due to the confinement of charge carriers within the nanoparticles. Similar to the effects of charge carriers on optical properties, confinement of optical and acoustic phonons leads to interesting changes in the phonon spectra. In the present work, we have synthesized nanoparticles of CdS using chemical precipitation technique. The crystal structure and grain size of the particles are studied using XRD. The UV–visible absorption, photoluminescence and Raman spectra of the sample are recorded and discussed briefly.

  20. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Castañeda, Mariela [Instituto Nacional de Investigaciones Nucleares (Mexico); Vega-Jiménez, Alejandro L., E-mail: argelia.almaguer@mac.com; Almaguer-Flores, Argelia [Universidad Nacional Autónoma de México, Facultad de Odontología, DEPeI, I (Mexico); Camps, Enrique; Pérez, Mario [Instituto Nacional de Investigaciones Nucleares (Mexico); Silva-Bermudez, Phaedra [Instituto Nacional de Rehabilitación, Unidad de Ingeniería de Tejidos, Terapia Celular y Medicina Regenerativa (Mexico); Berea, Edgardo [FarmaQuimia SA de CV. (Mexico); Rodil, Sandra E. [Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales (Mexico)

    2015-11-15

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.

  1. Characterization of silver nanoparticles synthesized on titanium dioxide fine particles

    Energy Technology Data Exchange (ETDEWEB)

    Nino-Martinez, N [Facultad de Ciencias, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Martinez-Castanon, G A [Maestria en Ciencias Odontologicas, Facultad de EstomatologIa, UASLP, Avenida Manuel Nava 2, Zona Universitaria, San Luis PotosI, SLP (Mexico); Aragon-Pina, A [Instituto de Metalurgia, Facultad de IngenierIa, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Martinez-Gutierrez, F [Facultad de Ciencias Quimicas, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Martinez-Mendoza, J R [Facultad de Ciencias, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Ruiz, Facundo [Facultad de Ciencias, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico)

    2008-02-13

    Silver nanoparticles with a narrow size distribution were synthesized over the surface of two different commercial TiO{sub 2} particles using a simple aqueous reduction method. The reducing agent used was NaBH{sub 4}; different molar ratios TiO{sub 2}:Ag were also used. The nanocomposites thus prepared were characterized using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), dynamic light scattering (DLS) and UV-visible (UV-vis) absorption spectroscopy; the antibacterial activity was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to the National Committee for Clinical Laboratory Standards. From the microscopy studies (TEM and STEM) we observed that the silver nanoparticles are homogeneously distributed over the surface of TiO{sub 2} particles and that the TiO{sub 2}:Ag molar ratio plays an important role. We used three different TiO{sub 2}Ag molar ratios and the size of the silver nanoparticles is 10, 20 and 80 nm, respectively. It was found that the antibacterial activity of the nanocomposites increases considerably comparing with separated silver nanoparticles and TiO{sub 2} particles.

  2. A green chemistry approach for synthesizing biocompatible gold nanoparticles

    Science.gov (United States)

    Gurunathan, Sangiliyandi; Han, JaeWoong; Park, Jung Hyun; Kim, Jin-Hoi

    2014-05-01

    Gold nanoparticles (AuNPs) are a fascinating class of nanomaterial that can be used for a wide range of biomedical applications, including bio-imaging, lateral flow assays, environmental detection and purification, data storage, drug delivery, biomarkers, catalysis, chemical sensors, and DNA detection. Biological synthesis of nanoparticles appears to be simple, cost-effective, non-toxic, and easy to use for controlling size, shape, and stability, which is unlike the chemically synthesized nanoparticles. The aim of this study was to synthesize homogeneous AuNPs using pharmaceutically important Ganoderma spp . We developed a simple, non-toxic, and green method for water-soluble AuNP synthesis by treating gold (III) chloride trihydrate (HAuCl4) with a hot aqueous extract of the Ganoderma spp . mycelia. The formation of biologically synthesized AuNPs (bio-AuNPs) was characterized by ultraviolet (UV)-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the biocompatibility of as-prepared AuNPs was evaluated using a series of assays, such as cell viability, lactate dehydrogenase leakage, and reactive oxygen species generation (ROS) in human breast cancer cells (MDA-MB-231). The color change of the solution from yellow to reddish pink and strong surface plasmon resonance were observed at 520 nm using UV-visible spectroscopy, and that indicated the formation of AuNPs. DLS analysis revealed the size distribution of AuNPs in liquid solution, and the average size of AuNPs was 20 nm. The size and morphology of AuNPs were investigated using TEM. The biocompatibility effect of as-prepared AuNPs was investigated in MDA-MB-231 breast cancer cells by using various concentrations of AuNPs (10 to 100 μM) for 24 h. Our findings suggest that AuNPs are non-cytotoxic and biocompatible. To the best of our knowledge

  3. A facile route to synthesize silver nanoparticles in polyelectrolyte capsules.

    Science.gov (United States)

    Anandhakumar, S; Raichur, Ashok M

    2011-06-01

    We are reporting a novel green approach to incorporate silver nanoparticles (NPs) selectively in the polyelectrolyte capsule shell for remote opening of polyelectrolyte capsules. This approach involves in situ reduction of silver nitrate to silver NPs using PEG as a reducing agent (polyol reduction method). These nanostructured capsules were prepared via layer by layer (LbL) assembly of poly(allylamine hydrochloride) (PAH) and dextran sulfate (DS) on silica template followed by the synthesis of silver NPs and subsequently the dissolution of the silica core. The size of silver nanoparticles synthesized was 60±20 nm which increased to 100±20 nm when the concentration of AgNO(3) increased from 25 mM to 50 mM. The incorporated silver NPs induced rupture and deformation of the capsules under laser irradiation. This method has advantages over other conventional methods involving chemical agents that are associated with cytotoxicity in biological applications such as drug delivery and catalysis. PMID:21333503

  4. Conductivity dependence on synthesis parameters in hydrothermally synthesized ceria nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Anis-ur-Rehman, M., E-mail: marehman@comsats.edu.pk; Saleemi, A.S.; Abdullah, A.

    2013-12-05

    Highlights: •Facile synthesis of CeO{sub 2} with composite mediated hydrothermal method is done. •Synthesis parameters significantly effect on conduction. •Enhanced dc electrical conductivity (0.3386 S cm{sup −1}) is observed at 700 °C. •Better ac conductivity is observed 2.661 S cm{sup −1} at 700 °C for 3 MHz. •Potential material for electrolyte in fuel cells for higher efficiencies. -- Abstract: Nanoparticles of cerium oxide were synthesized by Composite Mediated Hydrothermal Approach (CMHA). The synthesis conditions were optimized to enhance the conduction properties and for narrow range of nanocrystallites. The synthesis parameters like hydrothermal treatment temperature (at 180 °C and 220 °C) and time (for 45 min, 70 min and 90 min) were optimized. The structural properties of the prepared ceria were examined by X-ray diffraction (XRD) data. Scherrer’s formula was used to calculate the crystallite sizes of average and most intense peak. Temperature dependent dc conductivity was measured in temperature range 200–700 °C and found to be increasing with the increase in measuring temperature and controlling the other synthesis conditions. The frequency dependent ac conductivity and dielectric properties were measured in frequency range 20 Hz–3 MHz at different temperatures. The ac conductivity increased (from 0.00091 to 2.661 S cm{sup −1}) with the increase in temperature (from 200 to 700 °C). Raman spectrum was observed for the different bands of cerium oxide and oxygen vacancies at 514 nm excitation laser line.

  5. Anticancer studies of the synthesized gold nanoparticles against MCF 7 breast cancer cell lines

    Science.gov (United States)

    Kamala Priya, M. R.; Iyer, Priya R.

    2015-04-01

    It has been previously stated that gold nanoparticles have been successfully synthesized using various green extracts of plants. The synthesized gold nanoparticles were characterized under scanning electron microscopy and EDX to identify the size of the nanoparticles. It was found that the nanoparticles were around 30 nm in size, which is a commendable nano dimension achieved through a plant mediated synthesis. The nanoparticles were further studied for their various applications. In the current study, we have made attempts to exploit the anticancer ability of the gold nano particles. The nanoparticles were studied against MCF 7 breast cancer cell lines. The results obtained from the studies of anticancer activity showed that gold nanoparticles gave an equivalent good results, in par with the standard drugs against cancer. The AuNP's proved to be efficient even from the minimum concentrations of 2 μg/ml, and as the concentration increased the anticancer efficacy as well increased.

  6. Facile method to synthesize oleic acid-capped magnetite nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We described a simple one-step process for the synthesis of oleic acid-capped magnetite nanoparticles using the dimethyl sulfoxide(DMSO) to oxidize the precursor Fe~(2+) at 140℃.By adjusting the alkalinity of the reaction system,magnetite nanoparticles with two sizes of 4 and 7 nm could be easily achieved.And the magnetite nanoparticles coated by oleate were well-monodispersed in organic solvent.

  7. Versatile Solid Phase Syntheses of Structured Nanoparticle Hybrids

    Science.gov (United States)

    Koberstein, Jeffrey

    2011-03-01

    While it is widely recognized that nanoparticles can exhibit a wide variety of exciting size-dependent properties and responses, it is equally important to recognize that devices and systems cannot be created from bare nanoparticles alone. The potential of nanoparticles can only be achieved by proper consideration of matrices that not only provide mechanical support and integrity to the nanoparticles, but can also control various aspects of their spatial assembly such as geometry and interparticle spacing. Polymers represent a logical and robust matrix for the creation of nanocomposite assemblies, however, phenomena such as aggregation are often problematic when blending nanoparticles and homopolymers. These problems can be avoided by preparation of nanoparticle hybrids wherein all required polymers are covalently tethered to the nanoparticles prior to assembly so that a polymer matrix is not necessary. We report on a new method for covalent decoration of nanoparticles with polymers of tailored molecular design that is based upon a solid phase synthesis strategy. The modular process, much like molecular Tinker Toys, is capable of decorating nanoparticles with essentially any type of branched or copolymeric structure using only a few elementary heterobifunctional building blocks. Because end group functionality is always retained in the process, functional nanoparticles can be readily crosslinked by simple orthogonal reactions such as azide-alkyne click chemistry. The method can be used to create sophisticated hybrid nanoparticle structures important to drug delivery applications, to form highly functional crosslinkers that gel at conversions as low as a few percent, or to fabricate crosslinked matrix-free nanocomposites. Supported by grants DMR-0704054 from the NSF and W911NF-10-1-0184 from the US Army Research Office.

  8. Structure and Plasmonic Properties of Thin PMMA Layers with Ion-Synthesized Ag Nanoparticles

    DEFF Research Database (Denmark)

    Popok, Vladimir; Hanif, Muhammad; Mackova, Anna;

    2015-01-01

    nanoparticles above the surface. The synthesized nanoparticles can be split into two groups: (i) located at the surface and (ii) fully embedded in the shallow layer. These two groups provide corresponding spectral bands related to localized surface plasmon resonance. The bands demonstrate considerable intensity...

  9. Physically-synthesized gold nanoparticles containing multiple nanopores for enhanced photothermal conversion and photoacoustic imaging.

    Science.gov (United States)

    Park, Jisoo; Kang, Heesung; Kim, Young Heon; Lee, Sang-Won; Lee, Tae Geol; Wi, Jung-Sub

    2016-08-25

    Physically-synthesized gold nanoparticles having a narrow size distribution and containing multiple nanopores have been utilized as photothermal converters and imaging contrast agents. Nanopores within the gold nanoparticles make it possible to increase the light-absorption cross-section and consequently exhibit distinct improvements in photothermal conversion and photoacoustic imaging efficiencies.

  10. Physically-synthesized gold nanoparticles containing multiple nanopores for enhanced photothermal conversion and photoacoustic imaging.

    Science.gov (United States)

    Park, Jisoo; Kang, Heesung; Kim, Young Heon; Lee, Sang-Won; Lee, Tae Geol; Wi, Jung-Sub

    2016-08-25

    Physically-synthesized gold nanoparticles having a narrow size distribution and containing multiple nanopores have been utilized as photothermal converters and imaging contrast agents. Nanopores within the gold nanoparticles make it possible to increase the light-absorption cross-section and consequently exhibit distinct improvements in photothermal conversion and photoacoustic imaging efficiencies. PMID:27527067

  11. Pulsed-Thermal-Processing of Chemically Synthesized FePt Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Shifan [ORNL; Kang, Shishou [University of Alabama, Tuscaloosa; Lawson, Jeremy [University of Alabama, Tuscaloosa; Jia, Zhiyong [University of Alabama, Tuscaloosa; Nikles, David E. [University of Alabama, Tuscaloosa; Harrell, J. W. [University of Alabama, Tuscaloosa; Ott, Ronald D [ORNL; Kadolkar, Puja [ORNL

    2006-01-01

    The disordered face-centered-cubic A1 to the chemical ordered face-centered-tetragonal L1{sub 0} phase transformation of chemically synthesized magnetic FePt nanoparticles has been studied in the millisecond regime using a pulsed high-density plasma arc light source. Under select annealing conditions, relatively high magnetic coercivities (Hc) and anisotropies (Hk) of FePt nanoparticles were obtained with the millisecond pulse processing without significant sintering of the nanoparticles.

  12. Tuning Optical Nonlinearity of Laser-Ablation-Synthesized Silicon Nanoparticles via Doping Concentration

    Directory of Open Access Journals (Sweden)

    Lianwei Chen

    2014-01-01

    Full Text Available Silicon nanoparticles at different doping concentrations are investigated for tuning their optical nonlinear performance. The silicon nanoparticles are synthesized from doped silicon wafers by pulsed laser ablation. Their dispersions in water are studied for both nonlinear absorption and nonlinear refraction properties. It is found that the optical nonlinear performance can be modified by the doping concentration. Nanoparticles at a higher doping concentration exhibit better saturable absorption performance for femtosecond laser pulse, which is ascribed to the free carrier absorption mechanism.

  13. Evaluation of antioxidant, antibacterial and cytotoxic effects of green synthesized silver nanoparticles by Piper longum fruit

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, N. Jayachandra; Nagoor Vali, D.; Rani, M.; Rani, S. Sudha, E-mail: sadrassudha@gmail.com

    2014-01-01

    Silver nanoparticles synthesized through bio-green method has been reported to have biomedical applications to control pathogenic microbes as it is cost effective compared to commonly used physical and chemical methods. In present study, silver nanoparticles were synthesized using aqueous Piper longum fruit extract (PLFE) and confirmed by UV–visible spectroscopy. The nanoparticles were spherical in shape with an average particle size of 46 nm as determined by scanning electronic microscopy (SEM) and dynamic light scattering (DLS) particle size analyzer respectively. FT-IR spectrum revealed the capping of the phytoconstituents, probably polyphenols from P. longum fruit extract and stabilizing the nanoparticles. Further the ferric ion reducing test, confirmed that the capping agents were condensed tannins. The aqueous P. longum fruit extract (PLFE) and the green synthesized silver nanoparticles (PLAgNPs) showed powerful antioxidant properties in in vitro antioxidant assays. The results from the antimicrobial assays suggested that green synthesized silver nanoparticles (PLAgNPs) were more potent against pathogenic bacteria than the P. longum fruit extract (PLFE) alone. The nanoparticles also showed potent cytotoxic effect against MCF-7 breast cancer cell lines with an IC 50 value of 67 μg/ml/24 h by the MTT assay. These results support the advantages of using bio-green method for synthesizing silver nanoparticles with antioxidant, antimicrobial and cytotoxic activities those are simple and cost effective as well. - Highlights: • 46 nm spherical shaped P. longum fruit silver nanoparticles was prepared. • Capping and reducing bioactive plant compounds with in nanoparticles were condensed tannins. • Particles are potent antioxidant and anti microbial in biological systems. • They are cytotoxic against MCF-7 cell lines.

  14. Bacterially synthesized ferrite nanoparticles for magnetic hyperthermia applications

    Science.gov (United States)

    Céspedes, Eva; Byrne, James M.; Farrow, Neil; Moise, Sandhya; Coker, Victoria S.; Bencsik, Martin; Lloyd, Jonathan R.; Telling, Neil D.

    2014-10-01

    Magnetic hyperthermia uses AC stimulation of magnetic nanoparticles to generate heat for cancer cell destruction. Whilst nanoparticles produced inside magnetotactic bacteria have shown amongst the highest reported heating to date, these particles are magnetically blocked so that strong heating occurs only for mobile particles, unless magnetic field parameters are far outside clinical limits. Here, nanoparticles extracellularly produced by the bacteria Geobacter sulfurreducens are investigated that contain Co or Zn dopants to tune the magnetic anisotropy, saturation magnetization and nanoparticle sizes, enabling heating within clinical field constraints. The heating mechanisms specific to either Co or Zn doping are determined from frequency dependent specific absorption rate (SAR) measurements and innovative AC susceptometry simulations that use a realistic model concerning clusters of polydisperse nanoparticles in suspension. Whilst both particle types undergo magnetization relaxation and show heating effects in water under low AC frequency and field, only Zn doped particles maintain relaxation combined with hysteresis losses even when immobilized. This magnetic heating process could prove important in the biological environment where nanoparticle mobility may not be possible. Obtained SARs are discussed regarding clinical conditions which, together with their enhanced MRI contrast, indicate that biogenic Zn doped particles are promising for combined diagnostics and cancer therapy.Magnetic hyperthermia uses AC stimulation of magnetic nanoparticles to generate heat for cancer cell destruction. Whilst nanoparticles produced inside magnetotactic bacteria have shown amongst the highest reported heating to date, these particles are magnetically blocked so that strong heating occurs only for mobile particles, unless magnetic field parameters are far outside clinical limits. Here, nanoparticles extracellularly produced by the bacteria Geobacter sulfurreducens are

  15. Photocatalytic activity of BiFeO3 nanoparticles synthesized through hydrothermal method

    International Nuclear Information System (INIS)

    Multiferroic BiFeO3 (BFO) nanoparticles (Nps) were synthesized using hydrothermal method. From the X-Ray diffraction analysis (XRD), the synthesized Nps were found to having rhombohedral structure with R3c space group confirmed by Rietveld analysis. Fourier transform infrared spectroscopy (FTIR) analysis was carried out to identify the chemical bonds present in the BFO Nps. Photocatalytic properties of synthesized Nps were studied for the degradation of Methylene Blue (MB) dye under visible light of 150W

  16. Radiation synthesized protein-based nanoparticles: A technique overview

    International Nuclear Information System (INIS)

    Seeking for alternative routes for protein engineering a novel technique – radiation induced synthesis of protein nanoparticles – to achieve size controlled particles with preserved bioactivity has been recently reported. This work aimed to evaluate different process conditions to optimize and provide an overview of the technique using γ-irradiation. Papain was used as model protease and the samples were irradiated in a gamma cell irradiator in phosphate buffer (pH=7.0) containing ethanol (0–35%). The dose effect was evaluated by exposure to distinct γ-irradiation doses (2.5, 5, 7.5 and 10 kGy) and scale up experiments involving distinct protein concentrations (12.5–50 mg mL−1) were also performed. Characterization involved size monitoring using dynamic light scattering. Bityrosine detection was performed using fluorescence measurements in order to provide experimental evidence of the mechanism involved. Best dose effects were achieved at 10 kGy with regard to size and no relevant changes were observed as a function of papain concentration, highlighting very broad operational concentration range. Bityrosine changes were identified for the samples as a function of the process confirming that such linkages play an important role in the nanoparticle formation. - Highlights: • Synthesis of protein-based nanoparticles by γ-irradiation. • Optimization of the technique. • Overview of mechanism involved in the nanoparticle formation. • Engineered papain nanoparticles for biomedical applications

  17. Antibacterial activity of magnetic iron oxide nanoparticles synthesized by laser ablation in liquid

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Raid A., E-mail: raidismail@yahoo.com [Laser Physics Division, Applied Science Department, University of Technology, Baghdad (Iraq); Sulaiman, Ghassan M. [Biotechnology Division, Applied Science Department, University of Technology, Baghdad (Iraq); Abdulrahman, Safa A. [Laser Physics Division, Applied Science Department, University of Technology, Baghdad (Iraq); Marzoog, Thorria R. [Biotechnology Division, Applied Science Department, University of Technology, Baghdad (Iraq)

    2015-08-01

    In this study, (50–110 nm) magnetic iron oxide (α-Fe{sub 2}O{sub 3}) nanoparticles were synthesized by pulsed laser ablation of iron target in dimethylformamide (DMF) and sodium dodecyl sulfate (SDS) solutions. The structural properties of the synthesized nanoparticles were investigated by using Fourier Transform Infrared (FT-IR) spectroscopy, UV–VIS absorption, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The effect of laser fluence on the characteristics of these nanoparticles was studied. Antibacterial activities of iron oxide nanoparticles were tested against Gram-positive; Staphylococcus aureus and Gram-negative; Escherichia coli, Pseudomonas aeruginosa and Serratia marcescens. The results showed a noteworthy inhibition on both bacterial strains. The preparation conditions were found to affect significantly the antibacterial activity of these nanoparticles. The synthesized magnetic nanoparticles were used to capture rapidly S. aureus bacteria under the magnetic field effect. - Highlights: • Synthesis magnetic iron oxide nanoparticles by pulsed laser ablation • Antibacterial activity against Gram-positive and Gram-negative bacteria • Captured magnetic nanoparticles by S. aureus bacteria under effect of magnetic field.

  18. Biosynthesis of silver nanoparticles synthesized by Aspergillus flavus and their antioxidant, antimicrobial and cytotoxicity properties

    Indian Academy of Sciences (India)

    Ghassan M Sulaiman; Hiba T Hussien; Maysoon M N M Saleem

    2015-06-01

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour changes, UV–vis spectrum and X-ray diffraction (XRD) support the biosynthesis and characterization of silver nanoparticles. UV–vis spectral analysis showed silver surface plasmon resonance band at 420 nm. X-ray diffraction showed that the particles were crystalline with face-centred cubic structure at 45.05°, 65.45° and 78.65° and the size of the silver nanoparticles was 33.5 nm. The synthesized silver nanoparticles showed potent antimicrobial activity against various pathogens, including bacteria and fungi. Biosynthesized silver nanoparticles exhibited strong antioxidant activity as well as cytotoxicity against HL-60 cells in a dose–response relationship. The powerful bioactivity demonstrated by the synthesized silver nanoparticles leads towards the biomedical use as antioxidant, antibacterial and cytotoxic agents.

  19. A Study On Dispersion Stability Of Nickel Nanoparticles Synthesized By Wire Explosion In Liquid Media

    Directory of Open Access Journals (Sweden)

    Kim C.K.

    2015-06-01

    Full Text Available In this study, nickel nanoparticles were synthesized in ethanol using portable pulsed wire evaporation, which is a one-step physical method. From transmission electron microscopy images, it was found that the Ni nanoparticles exhibited a spherical shape with an average diameter of 7.3 nm. To prevent aggregation of the nickel nanoparticles, a polymer surfactant was added into the ethanol before the synthesis of nickel nanoparticles, and adsorbed on the freshly synthesized nickel nanoparticles during the wire explosion. The dispersion stability of the prepared nickel nanofluids was investigated by zeta-potential analyzer and Turbiscan optical analyzer. As a result, the optimum concentration of polymer surfactant to be added was suggested for the maximized dispersion stability of the nickel nanofluids.

  20. Generic approach for synthesizing asymmetric nanoparticles and nanoassemblies

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yugang; Hu, Yongxing

    2015-05-26

    A generic route for synthesis of asymmetric nanostructures. This approach utilizes submicron magnetic particles (Fe.sub.3O.sub.4--SiO.sub.2) as recyclable solid substrates for the assembly of asymmetric nanostructures and purification of the final product. Importantly, an additional SiO.sub.2 layer is employed as a mediation layer to allow for selective modification of target nanoparticles. The partially patched nanoparticles are used as building blocks for different kinds of complex asymmetric nanostructures that cannot be fabricated by conventional approaches. The potential applications such as ultra-sensitive substrates for surface enhanced Raman scattering (SERS) have been included.

  1. Red luminescence from hydrothermally synthesized Eu-doped ZnO nanoparticles under visible excitation

    Indian Academy of Sciences (India)

    P M Aneesh; M K Jayaraj

    2010-06-01

    Eu-doped ZnO nanoparticles were synthesized by hydrothermal method. The Eu-dopant concentration has been varied by varying the amount of Eu-dopant concentration. These nanoparticles were structurally characterized by X-ray diffraction, transmission electron microscopy and selected area electron diffraction and it confirms the formation of nanoparticles having standard wurtzite structure. Photoluminescence studies show that these nanoparticles exhibit a sharp red luminescence due to the intra-4 transitions of Eu3+ ions at an excitation of 397 nm and 466 nm. Luminescence quenching is observed in the nanoparticles as the Eu-dopant concentration increases. Incorporation of Eu in the nanoparticles was confirmed by the energy dispersive X-ray studies.

  2. Study of Ag and Au Nanoparticles Synthesized by Arc Discharge in Deionized Water

    Directory of Open Access Journals (Sweden)

    Der-Chi Tien

    2010-01-01

    Full Text Available The paper presents a study of Ag and Au nanofluids synthesized by the arc discharge method (ADM in deionized water. The metallic Ag nanoparticle (Ag0 and ionic Ag (Ag+ have played an important role in the battle against germs which are becoming more drug-resistant every year. Our study indicates that Ag nanoparticle suspension (SNPS fabricated by using ADM without added surfactants exclusively contains the metallic Ag nanoparticle and ionic Ag. Besides that, the ADM in deionized water has also been employed for the fabrication process of Au nanoparticles. The experimental results indicate that the prepared Ag nanoparticles can react with the dissolved H2CO3 in deionized water, leading to the formation of Ag2CO3. Significantly different to Ag, the prepared Au nanoparticles with their surfaces bonded by oxygen are suspended in deionized water by the formation of hydrogen bonded with the neighboring water molecules.

  3. Syntheses and applications of periodic mesoporous organosilica nanoparticles

    Science.gov (United States)

    Croissant, Jonas G.; Cattoën, Xavier; Wong Chi Man, Michel; Durand, Jean-Olivier; Khashab, Niveen M.

    2015-12-01

    Periodic Mesoporous Organosilica (PMO) nanomaterials are envisioned to be one of the most prolific subjects of research in the next decade. Similar to mesoporous silica nanoparticles (MSN), PMO nanoparticles (NPs) prepared from organo-bridged alkoxysilanes have tunable mesopores that could be utilized for many applications such as gas and molecule adsorption, catalysis, drug and gene delivery, electronics, and sensing; but unlike MSN, the diversity in chemical nature of the pore walls of such nanomaterials is theoretically unlimited. Thus, we expect that PMO NPs will attract considerable interest over the next decade. In this review, we will present a comprehensive overview of the synthetic strategies for the preparation of nanoscaled PMO materials, and then describe their applications in catalysis and nanomedicine. The remarkable assets of the PMO structure are also detailed, and insights are provided for the preparation of more complex PMO nanoplatforms.

  4. Optimization of adsorption process of Cadmium ions from synthetic wastewater using synthesized iron magnetic nanoparticles (Fe3O4

    Directory of Open Access Journals (Sweden)

    Leila Karimi Takanlu

    2014-10-01

    Conclusion: Magnetite nanoparticles exhibit high capability for removal of cadmium. The nanoparticles synthesized could be used at industrial scale because of having the magnetic property, which make them easily recovered from aqueous solution through applying a magnetic field.

  5. Radio-synthesized protein-based nanoparticles for biomedical purposes

    International Nuclear Information System (INIS)

    Protein-crosslinking whether done by enzymatic or chemically induced pathways increases the overall stability of proteins. In the continuous search for alternative routes for protein stabilization we report a novel technique – radio-induced synthesis of protein nanoparticles – to achieve size controlled particles with preserved bioactivity. Papain was used as model enzyme and the samples were irradiated at 10 kGy in a gammacell irradiator in phosphate buffer (pH=7.0) and additives such as ethanol (0–40%) and sodium chloride (0–25%). The structural rearrangement caused by irradiation under defined conditions led to an increase in papain particle size as a function of the additive and its concentration. These changes occur due to intermolecular bindings, of covalent nature, possibly involving the aromatic amino acids. Ethanol held major effects over papain particle size and particle size distribution if compared to sodium chloride. The particles presented relative retained bioactivity and the physic-chemical characterization revealed similar fluorescence spectra indicating preserved conformation. Differences in fluorescence units were observed according to the additive and its concentration, as a result of protein content changes. Therefore, under optimized conditions, the developed technique may be applied for enzyme nanoparticles formation of controllable size and preserved bioactivity. Highlights: • Novel technique for the development of protein nanoparticles using γ-irradiation. • Size control of papain particles with preserved conformation and bioactivity. • Alternative method for controlled protein crosslinking. • Bioactive protein nanoparticles of biotechnological and clinical interest. • Protein-based drug carrier potential of biotechnological and clinical interest

  6. A new way to synthesize ZnS nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Heng Zhi Zeng; Ke Qiang Qiu; Yuan Yuan Du; Wen Zhang Li

    2007-01-01

    ZnS nanoparticles were prepared with normal ZnO and Na2S by solid-liquid chemical reaction under ultrasonic condition and characterized by XRD, TEM, SEM, IR and TG-DTG. The results showed that these particles were good crystal cubic zinc blended with average size of 50 nm, possess good IR transmittance in the range of 400-4000 cm and good thermal stability.

  7. A facile one-pot method to synthesize ultrasmall core-shell superparamagnetic and upconversion nanoparticles.

    Science.gov (United States)

    Cheng, Qian; Guo, Hongxuan; Li, Yu; Liu, Shouxin; Sui, Jiehe; Cai, Wei

    2016-08-01

    Ultrasmall core-shell Fe3O4@NaYF4:Yb(3+)/Er(3+) nanoparticles with bifunctional properties have been successfully synthesized via one pot thermolysis method using oleylamine as both solvent and stabilizer. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), upconversion (UC) luminescence spectra and the physical properties measurement system (PPMS) were used to characterize the resulting samples. The synthesized samples have uniform morphology with a mean size of 14.5nm and excellent dispersibility. Moreover, these nanoparticles exhibit superparamagnetic behaviour with saturation magnetization of 8.45emμ/g and efficient up-conversion emission with a two-photon induced process when excited by a 980nm laser. These results suggest that the synthesized ultrasmall bifunctional nanoparticles may find many biomedical applications, such as clinical diagnosis and treatment of cancers. PMID:27135942

  8. Comparative Study on the Synergistic Action of Differentially Synthesized Silver Nanoparticles with β-Cephem Antibiotics and Chloramphenicol

    Directory of Open Access Journals (Sweden)

    Neethu Hari

    2014-01-01

    Full Text Available Synergistic activity of cephem antibiotics with silver nanoparticles (Ag NPs was investigated. Silver nanoparticles were synthesized through biological and chemical method. The combined action of β-lactam cephem antibiotics with both green and chemically synthesized silver nanoparticles enhances the antibacterial activity against wide range of antibiotic resistant pathogens and making them applicable to medical devices and microbial control systems. Synergistic activity of chloramphenicol with silver nanoparticles was also studied.

  9. Biocatalytic and antimicrobial activities of gold nanoparticles synthesized by Trichoderma sp.

    Science.gov (United States)

    Mishra, Aradhana; Kumari, Madhuree; Pandey, Shipra; Chaudhry, Vasvi; Gupta, K C; Nautiyal, C S

    2014-08-01

    The aim of this work was to synthesize gold nanoparticles by Trichoderma viride and Hypocrea lixii. The biosynthesis of the nanoparticles was very rapid and took 10 min at 30 °C when cell-free extract of the T. viride was used, which was similar by H. lixii but at 100 °C. Biomolecules present in cell free extracts of both fungi were capable to synthesize and stabilize the formed particles. Synthesis procedure was very quick and environment friendly which did not require subsequent processing. The biosynthesized nanoparticles served as an efficient biocatalyst which reduced 4-nitrophenol to 4-aminophenol in the presence of NaBH₄ and had antimicrobial activity against pathogenic bacteria. To the best of our knowledge, this is the first report of such rapid biosynthesis of gold nanoparticles within 10 min by Trichoderma having plant growth promoting and plant pathogen control abilities, which served both, as an efficient biocatalyst, and a potent antimicrobial agent.

  10. Evaluation of the Cytotoxic Behavior of Fungal Extracellular Synthesized Ag Nanoparticles Using Confocal Laser Scanning Microscope

    Directory of Open Access Journals (Sweden)

    Taher A. Salaheldin

    2016-03-01

    Full Text Available Silver nanoparticles have been synthesized by subjecting a reaction medium to a Fusarium oxysporum biomass at 28 °C for 96 h. The biosynthesized Ag nanoparticles were characterized on the basis of their anticipated peak at 405 nm using UV-Vis-NIR spectroscopy. Structural confirmation was evident from the characteristic X-ray diffraction (XRD pattern, high-resolution transmission electron Microscopy (HRTEM and the particle size analyzer. The Ag nanoparticles were of dimension 40 ± 5 nm and spherical in shape. The study mainly focused on using the confocal laser scanning microscope (CLSM to examine the cytotoxic activities of fungal synthesized Ag nanoparticles on a human breast carcinoma cell line MCF7 cell, which featured remarkable vacuolation, thus indicating a potent cytotoxic activity.

  11. Adsorption of Reactive Black 5 on Synthesized Titanium Dioxide Nanoparticles: Equilibrium Isotherm and Kinetic Studies

    OpenAIRE

    Majeed A. Shaheed; Falah H. Hussein

    2014-01-01

    The synthesized titanium dioxide nanoparticles (TiO2-NPs) were used as adsorbent to remove reactive black 5 (RB 5) in aqueous solution. Various factors affecting adsorption of RB 5 aqueous solutions such as pH, initial concentration, contact time, dose of nanoparticles, and temperature were analyzed at fixed solid/solution ratio. Langmuir and Freundlich isotherms were used as model adsorption equilibrium data. Langmuir isotherm was found to be the most adequate model. The pseudo-first-order, ...

  12. Oxidative stress mediated cytotoxicity of biologically synthesized silver nanoparticles in human lung epithelial adenocarcinoma cell line

    Science.gov (United States)

    Han, Jae Woong; Gurunathan, Sangiliyandi; Jeong, Jae-Kyo; Choi, Yun-Jung; Kwon, Deug-Nam; Park, Jin-Ki; Kim, Jin-Hoi

    2014-09-01

    The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate . The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles.

  13. Electrocatalysis of chemically synthesized noble metal nanoparticles on carbon electrodes

    DEFF Research Database (Denmark)

    Zhang, Ling; Ulstrup, Jens; Zhang, Jingdong

    Noble metal nanoparticles (NPs), such as platinum (Pt) and palladium (Pd) NPs are promising catalysts for dioxygen reduction and oxidation of molecules such as formic acid and ethanol in fuel cells. Carbon nanomaterials are ideal supporting materials for electrochemical catalysts due to their good...... conductivity, chemical inertness and low cost. Improvement of catalytic efficiency and stability of the NPs is, however, essential for their wider applications in electrochemical energy conversion/storage. The activities of noble metal catalysts depend not only on their size, composition, and shapes but also...

  14. CATALYTIC PROPERTIES OF POLYMER-STABILIZED COLLOIDAL METAL NANOPARTICLES SYNTHESIZED BY MICROWAVE IRRADIATION

    Institute of Scientific and Technical Information of China (English)

    Wei-xia Tu; Bao-lin He; Han-fan Liu; Xue-lan Luo; Xun Liang

    2005-01-01

    Catalytic properties of polymer-stabilized colloidal metal nanoparticles synthesized by microwave irradiation were studied in the selective hydrogenation of unsaturated aldehydes, o-chloronitrobenzene and the hydrogenation of alkenes. The results show that nanosized metal particles synthesized by microwave irradiation have similar catalytic performance in selective hydrogenation of unsaturated aldehydes, better selectivity to o-chloroaniline in hydrogenation of o-chloronitrobenzene and higher catalytic activities in hydrogenation of alkenes, compared with metal clusters prepared by conventional heating. The same apparent activation energy (Ea = 29 kJ mol-1) for hydrogenation of 1-heptene catalyzed with platinum nanoparticles prepared by both heating modes implied that the reaction followed the same mechanism.

  15. Ag recovery from copper anode slime by acid leaching at atmospheric pressure to synthesize silver nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Atefeh Khaleghi; Sattar Ghader; Dariush Afzali

    2014-01-01

    In this paper, recovery of silver from anode slime of Sarcheshmeh copper complex in Iran and subsequent synthesis of silver nanoparticles from leaching solution is investigated. Sarcheshmeh anode slime is mainly consisted of Cu, Ag, Pb and Se. Amount of Ag in the considered anode slime was 5.4%(by weight). The goal was to recover as much as possible Ag from anode slime at atmospheric pressure to synthesize Ag nanoparticles. Therefore, acid leaching was used for this purpose. The anode slime was leached with sulfuric and nitric acid from room to 90 ?C at different acid concentrations and the run which yielded the most recovery of Ag was selected for Ag nanoparticles synthesis. At this condition, Cu, Pb and Se are lea-ched as well as Ag. To separate Ag from leach solution HCl was added and silver was precipitated as AgCl which were then dissolved by ammonia solution. The Ag nanoparticles are synthesized from this solution by chemical reduction method by aid of sodium borohydride in the presence of PVP and PEG as stabiliz-ers. The synthesized Ag nanoparticles showed a peak of 394 nm in UV-vis spectrum and TEM images showed a rather uniform Ag nanoparticles of 12 nm.

  16. A comparative study of TiO2 nanoparticles synthesized in premixed and diffusion flames

    Science.gov (United States)

    Ma, Hsiao-Kang; Yang, Hsiung-An

    2010-12-01

    Previous studies have been shown that synthesis of titania (TiO2) crystalline phase purity could be effectively controlled by the oxygen concentration through titanium tetra-isopropoxide (TTIP) via premixed flame from a Bunsen burner. In this study, a modified Hencken burner was used to synthesize smaller TiO2 nanoparticles via short diffusion flames. The frequency of collisions among particles would decrease and reduce TiO2 nanoparticle size in a short diffusion flame height. The crystalline structure of the synthesized nanoparticles was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Barrett-Joyner-Halenda (BJH) and Brunauer-Emmett-Teller (BET) measurements. The characteristic properties of TiO2 nanoparticles synthesized from a modified Hencken burner were compared with the results from a Bunsen burner and commercial TiO2 (Degussa P25). The results showed that the average particle size of 6.63 nm from BET method was produced by a modified Hencken burner which was smaller than the TiO2 in a Bunsen burner and commercial TiO2. Moreover, the rutile content of TiO2 nanoparticles increased as the particle collecting height increased. Also, the size of TiO2 nanoparticles was highly dependent on the TTIP loading and the collecting height in the flame.

  17. Studies on Mechanochemical Method to Synthesize LDH Nanoparticles%Studies on Mechanochemical Method to Synthesize LDH Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Jia, Chunxiao; Zhang, Xiaoqing; Li, Shuping

    2012-01-01

    Magnesium-ferrum layered double hydroxide (Mg-Fe-LDH) and zinic-aluminum layered double hydroxide (Zn-A1-LDH) compounds were prepared through a mechanochemical method. The influence of molar ratio of M2+ to M3+ (R value) on the property ofLDH nanoparticles has been studied and the results showed that R=3 : 1 is the optimum value for the both samples. Besides pure water, the mixture of water and ethanol with the volume ratio of 3 ; 1 is also used to wash the precipitates and used as suspending agent during the peptization process and our results showed that the addition of ethanol can improve the monodispersity of LDH nanoparticles greatly.

  18. Radio-synthesized protein-based nanoparticles for biomedical purposes

    Science.gov (United States)

    Varca, Gustavo H. C.; Ferraz, Caroline C.; Lopes, Patricia S.; Mathor, Monica beatriz; Grasselli, Mariano; Lugão, Ademar B.

    2014-01-01

    Protein-crosslinking whether done by enzymatic or chemically induced pathways increases the overall stability of proteins. In the continuous search for alternative routes for protein stabilization we report a novel technique - radio-induced synthesis of protein nanoparticles - to achieve size controlled particles with preserved bioactivity. Papain was used as model enzyme and the samples were irradiated at 10 kGy in a gammacell irradiator in phosphate buffer (pH=7.0) and additives such as ethanol (0-40%) and sodium chloride (0-25%). The structural rearrangement caused by irradiation under defined conditions led to an increase in papain particle size as a function of the additive and its concentration. These changes occur due to intermolecular bindings, of covalent nature, possibly involving the aromatic amino acids. Ethanol held major effects over papain particle size and particle size distribution if compared to sodium chloride. The particles presented relative retained bioactivity and the physic-chemical characterization revealed similar fluorescence spectra indicating preserved conformation. Differences in fluorescence units were observed according to the additive and its concentration, as a result of protein content changes. Therefore, under optimized conditions, the developed technique may be applied for enzyme nanoparticles formation of controllable size and preserved bioactivity.

  19. Measurement of discrete energy-level spectra in individual chemically synthesized gold nanoparticles

    DEFF Research Database (Denmark)

    Kuemmeth, Ferdinand; Bolotin, Kirill I; Shi, Su-Fei;

    2008-01-01

    We form single-electron transistors from individual chemically synthesized gold nanoparticles, 5-15 nm in diameter, with monolayers of organic molecules serving as tunnel barriers. These devices allow us to measure the discrete electronic energy levels of individual gold nanoparticles that are, by...... virtue of chemical synthesis, well-defined in their composition, size and shape. We show that the nanoparticles are nonmagnetic and have spectra in good accord with random-matrix-theory predictions taking into account strong spin-orbit coupling....

  20. Antibacterial Activity of Silver Nanoparticles Synthesized by Bark Extract of Syzygium cumini

    Directory of Open Access Journals (Sweden)

    Ram Prasad

    2013-01-01

    Full Text Available The unique property of the silver nanoparticles having the antimicrobial activity drags the major attention towards the present nanotechnology. The environmentally nontoxic, ecofriendly, and cost-effective method that has been developed for the synthesis of silver nanoparticles using plant extracts creates the major research interest in the field of nanobiotechnology. The synthesized silver nanoparticles have been characterized by the UV-visible spectroscopy, atomic force microscopy (AFM, and scanning electron microscopy (SEM. Further, the antibacterial activity of silver nanoparticles was evaluated by well diffusion method, and it was found that the biogenic silver nanoparticles have antibacterial activity against Escherichia coli (ATCC 25922, Staphylococcus aureus (ATCC 29213, Pseudomonas aeruginosa (ATCC 27853, Azotobacter chroococcum WR 9, and Bacillus licheniformis (MTCC 9555.

  1. Evaluation of antibacterial activity of zinc oxide nanoparticles synthesized using phycobilins of Anabaena variabilis NTSS17

    Directory of Open Access Journals (Sweden)

    Thangaraj Ramasamy

    2015-12-01

    Full Text Available Objective: To evaluate the antibacterial activity of zinc oxide nanoparticles synthesized using phycobilins of Anabaena variabilis NTSS17. Methods: The cyanobacterial isolate was collected from paddy field and morphologically identified as Anabaena variabilis NTSS17, that produces a pigment i.e. phycobiliproteins. The biosynthesized zinc nanoparticles were characterized by different spectroscopic and analytical techniques such as UV-visible spectrophotometer, Fourier transform infrared spectroscopy and X-ray diffraction which confirmed the formation of zinc nanoparticles. Results: Antibacterial activity of zinc oxide nanoparticles was examined against Escherichia coli, Rhodococcus rhodochrous and Pseudomonas aeruginosa. The maximum zone of inhibition occurred at 5 mg/1000 mL concentration of zinc oxide nanoparticles. Conclusions: Due to potent antimicrobial and intrinsic properties of zinc oxide, it can be actively used for biomedical applications.

  2. Photocatalytic activity of biogenic silver nanoparticles synthesized using potato (Solanum tuberosum) infusion

    Science.gov (United States)

    Roy, Kaushik; Sarkar, C. K.; Ghosh, C. K.

    2015-07-01

    In this study, we have reported a fast and eco-benign procedure to synthesis silver nanoparticle at room temperature using potato (Solanum tuberosum) infusion along with the study of its photocatalytic activity on methyl orange dye. After addition of potato infusion to silver nitrate solution, the color of the mixture changed indicating formation of silver nanoparticles. Time dependent UV-Vis spectra were obtained to study the rate of nanoparticle formation with time. Purity and crystallinity of the biogenic silver nanoparticles were examined by X-ray diffraction (XRD). Average size and morphology of the nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infra-red spectroscopy (FTIR) was employed to detect functional bio-molecules responsible that contribute to the reduction and capping of biosynthesized Ag nanoparticles. Further, these synthesized nanoparticles were used to investigate their ability to degrade methyl orange dye under sunlight irradiation and the results showed effective photocatalytic property of these biogenic silver nanoparticles.

  3. Antimicrobial and cytotoxicity effect of silver nanoparticle synthesized by Croton bonplandianum Baill. leaves

    Directory of Open Access Journals (Sweden)

    K. Khanra

    2016-01-01

    Full Text Available Objective(s: For the development of reliable, ecofriendly, less expensive process for the synthesis of silver nanoparticles and to evaluate the bactericidal, and cytotoxicity properties of silver nanoparticles synthesized from root extract of Croton bonplandianum, Baill. Materials and Methods: The synthesis of silver nanoparticles by plant part of Croton bonplandianum was carried out.  The formation of nanoparticles was confirmed by Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM, XRD and UV-Vis spectrophotometric analysis.  The biochemical properties were assayed by antibacterial study, cytotoxicity assay using cancer cell line.  Results: The formation of silver nanoparticles was confirmed by UV-VIS spectroscopic analysis which showed absorbance peak at 425 nm.  X-ray diffraction photograph indicated the face centered cubic structure of the synthesized AgNPs.  TEM has displayed the different dimensional images of biogenic silver nanoparticles with particle size distribution ranging from 15-40 nm with an average size of 32 nm. Silver particles are spherical in shape, clustered.  The EDX analysis was used to identify the elemental composition of synthesized AgNPs. Antibacterial activity of the synthesized AgNPs against three Gram positive and Gram negative bacteria strains like Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa carried out showed significant zones of inhibition. The cytotoxicity study by AgNPS also showed cytotoxicity on ovarian cancer cell line PA-1 and lung epithelial cancer cell line A549.  Conclusion: The present study confirms that the AgNPs have great promise as antibacterial, and anticancer agent.

  4. Physically synthesized Ni-Cu nanoparticles for magnetic hyperthermia

    Science.gov (United States)

    Bettge, Martin; Chatterjee, Jhunu; Haik, Yousef

    2004-01-01

    Background In this paper, a physical method to prepare copper-nickel alloy particles in the sub-micron range for possible self controlled magnetic hyperthermia treatment of cancer is described. It is reported that an increase in tumor temperature decreases the tumor resistance to chemo- and radiation therapies. Self controlled heating at the tumor site to avoid spot heating is managed by controlling the Curie temperature of the magnetic particles. The process described in this paper to produce the nanomagnetic particles allows for a large scale production of these particles. Methods The process used here is mainly composed of melting of the Cu-Ni mixture and ball milling of the resulted bulk alloy. Both mechanical abrasion and continuous grinding were used to break down the bulk amount into the desired particle size. Results It was found that the desired alloy is composed of 71% nickel and 29% copper by weight. It was observed that the coarse sand-grinded powder has a Curie temperature of 345 K and the fine ball-milled powder shows a temperature of 319 K – 320 K. Conclusion Self regulating magnetic hyperthermia can be achieved by synthesizing nanomagnetic particles with desired Curie temperature. In this study the desired range of Curie temperatures was obtained by combination of melting and ball milling of nickel-copper alloy. PMID:15132747

  5. Solvent effect on the size of platinum nanoparticle synthesized in microemulsion systems

    Science.gov (United States)

    Salabat, Alireza; Far, Mina Rahmati

    2012-05-01

    In this research work, the effect of solvent on the size of paltinum nanoparticles synthesized by microemulsion method was investigated. Platinum nanoparticles have been prepared by the reduction of H2PtCl6 with hydrazine in water-in-oil (w/o) microemulsions consisting of sodium bis(2-ethylhexyl) sulfo-succinate (AOT) and solvents n-hexane, cyclohexane and n-nonane. The size of the platinum nanoparticles was measured using transmission electron microscopy (TEM). It was verified that, for reduction of H2PtCl6 by hydrazine in microemulsion with different organic solvents, the solvents are arranged by their influence on nanoparticle sizes as follows: n-nonane > cyclohexane > n-hexane.

  6. Single crystal ZnO:Al nanoparticles directly synthesized using low-pressure spray pyrolysis

    International Nuclear Information System (INIS)

    Aluminum-doped zinc oxide (AZO) nanoparticles powder were prepared using low-pressure spray pyrolysis (LPSP). AZO nanoparticles sized 16 and 20 nm with nearly spherical shapes and a crystal size of 11 and 15 nm were yielded using zinc acetate precursor at a low-pressure of 8.0 kPa with a pyrolysis temperature of 800 and 1000 deg. C. The thin films were deposited using a dip-coating method derived from the as-prepared AZO nanoparticles. The thin films that were heated for 1.5 h showed a transmittance higher than 97% in the wavelength range of 400-800 nm and a resistivity of 4.0 x 103 ohm cm with a film thickness of 250 nm. The high crystallinity and high transmittance of AZO nanoparticles that are directly synthesized using the LPSP process have potential for applications as transparent conducting material

  7. In situ synthesized gold nanoparticles in hydrogels for catalytic reduction of nitroaromatic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xiao-Qiong; Wu, Xing-Wen; Huang, Qing [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Shen, Jiang-Shan, E-mail: jsshen@iue.ac.cn [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Ningbo Urban Environment Observation and Research Station, Chinese Academy of Sciences, Ningbo 315800 (China); Zhang, Hong-Wu, E-mail: hwzhang@iue.ac.cn [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2015-03-15

    Graphical abstract: - Highlights: • In situ preparing Au nanoparticles by photoreduction in chitosan hydrogels was firstly achieved. • In situ photoreduction for creating Au nanoparticles is environmentally friendly and the operation procedure is very simple. • The as-prepared Au nanoparticles have good catalytic performance. • Affording an effective strategy for converting some high explosive compounds such as 2,4,6-tNT to nonexplosive. - Abstract: Developing hydrogel systems featured by catalytic active is of importance to construct highly effective platforms for removing environmental pollutants/hazardous substances or for bio-/chemosensing. Reported herein are our recent finding that Au nanoparticles could be in situ prepared in chitosan-Au{sup III} hydrogel system via photoreduction, and the as-prepared Au nanoparticles could be employed for the catalytic reduction of a series of nitroaromatic compounds by sodium borohydride (NaBH{sub 4}). Experimental conditions of synthesizing Au nanoparticles, including pH, concentration of Au{sup III}, and light irradiation time were systematically investigated. The as-prepared Au nanoparticles were characterized by UV–vis absorption spectroscopy, X-ray diffraction (XRD), transmission and field emission scanning electron microscopy (TEM and FESEM). This is the first example for in situ formed metal nanoparticles in chitosan hydrogel systems via photoreduction. The effectiveness of the as-prepared Au nanoparticles as nanocatalysts was evaluated by employing the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH{sub 4} as a model reaction. The catalytic reduction reaction was found to be very efficient and to follow a pseudo-first-order kinetics. The as-prepared Au nanoparticles demonstrated good reusability and stability. The reduction of a series of other nitroaromatic compounds including highly explosives 2,4,6-trinitrophenol (2,4,6-tNP) and 2,4,6-trinitrotoluene (2,4,6-tNT) was achieved by means

  8. A comparative study on biologically and chemically synthesized silver nanoparticles induced Heat Shock Proteins on fresh water fish Oreochromis niloticus.

    Science.gov (United States)

    Girilal, M; Krishnakumar, V; Poornima, Paramasivan; Mohammed Fayaz, A; Kalaichelvan, P T

    2015-11-01

    The wide applicability of silver nanoparticles in medicine and pharmaceutical industries leads to its over exploitation and thus contaminating our environment. Majority of these nanoscale dimension particles finally accumulates in fresh water and marine ecosystem. As the nanoparticles behave entirely different from its corresponding bulk material, a better understanding of their environmental impacts in aquatic ecosystems is inevitable. The study was focused on a comparative stress physiology analysis of chemically synthesized silver nanoparticles and biogenic silver nanoparticles. Half maximal inhibitory concentration of biologically synthesized and chemically synthesized nanoparticles was found out (30μg/mL and 20μg/mL respectively). The Heat Shock Protein (HSP70) secretion was analysed in the fresh water fish Oreochromis niloticus after exposing to different concentrations of biologically and chemically synthesized silver nanoparticles along with the silver in its ionic form. The intense immune-histochemical staining of fish tissues (muscle, kidney and liver) analyzed proportionately reflected the stress created. The colour intensity was directly proportional to the stress created or the stress protein released. High level of HSP70 expression was observed in all of the fish tissues exposed to silver ions and chemically synthesized silver nanoparticles, when compared to that of biologically synthesized. The results revealed the significance of comparatively safe and less toxic biogenic nanoparticles compared to the chemically synthesized.

  9. Gas Sensors Based on Tin Oxide Nanoparticles Synthesized from a Mini-Arc Plasma Source

    Directory of Open Access Journals (Sweden)

    Ganhua Lu

    2006-01-01

    Full Text Available Miniaturized gas sensors or electronic noses to rapidly detect and differentiate trace amount of chemical agents are extremely attractive. In this paper, we report on the fabrication and characterization of a functional tin oxide nanoparticle gas sensor. Tin oxide nanoparticles are first synthesized using a convenient and low-cost mini-arc plasma source. The nanoparticle size distribution is measured online using a scanning electrical mobility spectrometer (SEMS. The product nanoparticles are analyzed ex-situ by high resolution transmission electron microscopy (HRTEM for morphology and defects, energy dispersive X-ray (EDX spectroscopy for elemental composition, electron diffraction for crystal structure, and X-ray photoelectron spectroscopy (XPS for surface composition. Nonagglomerated rutile tin oxide (SnO2 nanoparticles as small as a few nm have been produced. Larger particles bear a core-shell structure with a metallic core and an oxide shell. The nanoparticles are then assembled onto an e-beam lithographically patterned interdigitated electrode using electrostatic force to fabricate the gas sensor. The nanoparticle sensor exhibits a fast response and a good sensitivity when exposed to 100 ppm ethanol vapor in air.

  10. Spectroscopic, microscopic and catalytic properties of silver nanoparticles synthesized using Saraca indica flower

    Science.gov (United States)

    Vidhu, V. K.; Philip, Daizy

    2014-01-01

    The bioprospective field is dynamic area of research in the recent years. The present article reports a green synthetic route for the production of highly stable, bio-inspired silver nanoparticles using dried Saraca indica flower. The method is facile, cost effective, simple and reproducible. The reduction of silver ions and the formation of silver nanoparticles has been monitored using UV-visible spectroscopy. The TEM, SAED and XRD result reveal that the silver nanoparticles are crystalline in nature. FTIR spectra are used to identify the biomolecules that bind on the surface of silver nanoparticles, which increased the stability of the particles. S. indica flower extract plays its role as an excellent reducing agent of silver ions and the biosynthesized silver nanoparticles are safer to environment. Also the size dependent catalytic activity of silver nanoparticles in the reduction of cationic dye, Methylene blue by NaBH4 is studied by UV-visible spectroscopy. The efficiency of synthesized nanoparticles as an excellent catalyst is proved by the reduction of Methylene blue which is confirmed by the decrease in the absorbance with time and is attributed to electron relay effect.

  11. Sol-gel synthesized mesoporous anatase titanium dioxide nanoparticles for dye sensitized solar cell (DSSC) applications

    Indian Academy of Sciences (India)

    R Govindaraj; M Senthil Pandian; P Ramasamy; Sumita Mukhopadhyay

    2015-04-01

    Hierarchically structured titanium dioxide nanoparticles were successfully synthesized by the sol-gel method. The synthesized nanoparticles were subjected to powder X-ray diffraction, UV-Vis DRS spectroscopy, Brunauer–Emmett–Teller method, Barrett–Joyner–Halenda analysis, field emission scanning electron microscopy, high-resolution transmission electron microscopy and energy-dispersive X-ray analysis. The powder X-ray diffraction pattern shows that the obtained particles are of anatase phase with good crystallite nature. The nitrogen adsorption and desorption isotherms show that the prepared material has surface area of 31.71 m2 g-1 and the pore size distribution analysis shows the average pore diameters of mesoporous TiO2 nanostructures to be 7.1 and 9.3 nm. The UV–Vis DRS spectrum shows that the TiO2 nanoparticles are having absorption in the ultraviolet region. The optical band gap of the nanoparticles is 3.2 eV. The morphological studies show the morphology of the particles as spherical in shape. The elemental compositions of TiO2 nanoparticles were confirmed by energy-dispersive X-ray spectrum analysis. The conversion efficiency of the solar cell was 3.415% with open-circuit voltage (oc), short-circuit current (sc) and fill factor (FF) of 0.607 V, 13.206 mA cm-2 and 42.56%, respectively.

  12. Polymer-templated mesoporous carbons synthesized in the presence of nickel nanoparticles, nickel oxide nanoparticles, and nickel nitrate

    Science.gov (United States)

    Choma, Jerzy; Jedynak, Katarzyna; Marszewski, Michal; Jaroniec, Mietek

    2012-02-01

    Mesoporous carbon composites, containing nickel and nickel oxide nanoparticles, were obtained by soft-templating method. Samples were synthesized under acidic conditions using resorcinol and formaldehyde as carbon precursors, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock co-polymer Lutrol F127 as a soft template and nickel and nickel oxide nanoparticles, and nickel nitrate as metal precursors. In addition, a one set of samples was obtained by impregnation of mesoporous carbons with a nickel nitrate solution followed by further annealing at 400 °C. Wide angle X-ray powder diffraction along with thermogravimetric analysis proved the presence of nickel nanoparticles in the final composites obtained using nickel and nickel oxide nanoparticles, and Ni(NO3)2 solution. Whereas, the impregnation of carbons with a nickel nitrate solution followed by annealing at 400 °C resulted in needle-like nickel oxide nanoparticles present inside the composites’ pores. Low-temperature (-196 °C) nitrogen physisorption, X-ray powder diffraction, and thermogravimetric analysis confirmed good adsorption and structural properties of the synthesized nickel-carbon composites, in particular, the samples possessed high surface areas (>600 m2/g), large total pore volumes (>0.50 cm3/g), and maxima of pore size distribution functions at circa 7 nm. It was found that the composites were partially graphitized during carbonization process at 850 °C. The samples are stable in an air environment below temperature of 500 °C. All these features make the synthesized nickel-carbon composites attractive materials for adsorption, catalysis, energy storage, and environmental applications.

  13. Metal Carboxylate Nanorods and Metal Oxide Nanoparticles Synthesized Using Reverse Micelles

    Institute of Scientific and Technical Information of China (English)

    Ashok.K.Ganguli(Department; of; Chemistry; Indian; Institute; of; Technology

    2007-01-01

    1 Results Nanorods of transition metal (Cu,Ni,Mn,Zn,Co and Fe) carboxylates (oxalates and succinates) have been synthesized using a reverse-micellar technique[1-3].These oxalate nanorods have been shown to be an ideal source for obtaining monophasic and homogeneous nanoparticles of transition metal oxides at low temperatures of 450 ℃.Grain size of oxide nanoparticles could be controlled by optimizing the nature of non-polar solvent and surfactant.The metal oxalate precursor could be decomposed in suitab...

  14. Mn-Zn soft magnetic ferrite nanoparticles synthesized from spent alkaline Zn-Mn batteries

    International Nuclear Information System (INIS)

    Research highlights: → This manuscript reports for the first time to prepare Mn-Zn soft magnetic ferrite nanoparticles using spent alkaline Zn-Mn batteries as raw material by multi-step processes including acid leaching, chemical treatment of battery iron shells and citrate-nitrate precursor auto-combustion. → Synthesized Mn0.5Zn0.5Fe2O4 ferrite nanoparticles have pure ferrite phase, larger saturation magnetization and lower coercivity compared with the same composition ferrites prepared by other techniques due to better crystallinity. → Auto-combustion Mn-Zn ferrite nanoparticles synthesis method presents a viable alternative for alkaline Zn-Mn batteries recycling due to its target product is not a single metal or its oxide. → It is original and not currently submitted for review to any other journal and their intent is to publish the article in the Journal of Alloys and Compounds. - Abstract: Using spent alkaline Zn-Mn batteries as raw material, Mn-Zn soft magnetic ferrite nanoparticles are prepared by multi-step processes including acid leaching, chemical treatment of battery iron shells and citrate-nitrate precursor auto-combustion. Acid leaching and chemical treatment mechanisms are investigated. Dried gels thermal decomposition process, auto-combustion, phase composition, morphological and magnetic properties of as-prepared Mn-Zn ferrite nanoparticles are characterized by thermogravimetric and differential thermal analysis, X-ray powder diffraction, transmission electron microscopy and vibrating sample magnetometer. Synthesized Mn-Zn ferrite nanoparticles (Mn0.5Zn0.5Fe2O4) have pure ferrite phase, larger saturation magnetization (Ms = 60.62 emu g-1) and lower coercivity (Hc = 30 Oe) compared with the same composition ferrites prepared by other techniques due to better crystallinity. Mn-Zn ferrite nanoparticles synthesis method presents a viable alternative for alkaline Zn-Mn batteries recycling.

  15. Optical properties of ion-beam-synthesized Au nanoparticles in SiO2 matrix

    Science.gov (United States)

    Hsieh, Chang-Lin; Oyoshi, Keiji; Chao, Der-Sheng; Tsai, Hsu-Sheng; Hong, Wei-Lun; Takeda, Yoshihiko; Liang, Jenq-Horng

    2016-05-01

    In recent years, gold (Au) nanoparticles have been synthesized via various methods and used in optical and biomedical detection. Au nanoparticles contain some remarkable dimension-dependent optical properties due to surface plasmon resonance (SPR) in Au nanoparticles which causes high absorption in visible light regions. Since SPR in well-crystallized Au nanoparticles can enhance the local electromagnetic field, it is thus expected that greater efficiency in the photoluminescence (PL) originating from oxygen deficiency centers (ODC) can be achieved in Au-implanted SiO2 matrix. In order to demonstrate the enhancement of PL, Au nanoparticles were formed in SiO2 film using ion beam synthesis and their optical and microstructural properties were also investigated in this study. The results revealed that a clear absorption peak at approximately 530 nm was identified in the UV-Vis spectra and was attributed to SPR induced by Au nanoparticles in SiO2. The SPR of Au nanoparticles is also dependent on thermal treatment conditions, such as post-annealing temperature and ambient. The Au nanoparticle-containing SiO2 film also displayed several distinctive peaks at approximately 320, 360, 460, and 600 nm in the PL spectra and were found to be associated with ODC-related defects and non-bridging oxygen hole centers (NBOHC) in SiO2. In addition, the PL peak intensities increased as post-annealing temperature increased, a finding contradictory to the defect recovery but highly consistent with the SPR tendency. A maximum PL emission was achieved when the Au-implanted SiO2 film was annealed at 1100 °C for 1 h under N2. Therefore, the existence of Au nanoparticles in SiO2 film can induce SPR effects as well as enhance PL emission resulting from defect-related luminescence centers.

  16. Mycosynthesis: antibacterial, antioxidant and antiproliferative activities of silver nanoparticles synthesized from Inonotus obliquus (Chaga mushroom) extract.

    Science.gov (United States)

    Nagajyothi, P C; Sreekanth, T V M; Lee, Jae-il; Lee, Kap Duk

    2014-01-01

    In the present study, silver nanoparticles (AgNPs) were rapidly synthesized from silver nitrate solution at room temperature using Inonotus obliquus extract. The mycogenic synthesized AgNPs were characterized by UV-Visible absorption spectroscopy, Fourier transform infrared (FTIR), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). SEM revealed mostly spherical nanoparticles ranging from 14.7 to 35.2nm in size. All AgNPs concentrations showed good ABT radical scavenging activity. Further, AgNPs showed effective antibacterial activity against both gram negative and gram positive bacteria and antiproliferative activity toward A549 human lung cancer (CCL-185) and MCF-7 human breast cancer (HTB-22) cell lines. The samples demonstrated considerably high antibacterial, and antiproliferative activities against bacterial strains and cell lines. PMID:24380885

  17. Kinetics of oxygen adsorption on ZnS nanoparticles synthesized by precipitation process

    Directory of Open Access Journals (Sweden)

    Ahmadi Reza

    2016-06-01

    Full Text Available ZnS nanoparticles were synthesized through a one-step precipitation process. Effect of time and temperature on the formation reaction was investigated. The synthesized samples were characterized by X-ray diffraction (XRD, ultraviolet (UV visible absorption and photoluminescence (PL spectrophotometry. Based on XRD and UV-Vis data, the particles produced at 70 °C had a mean particle size of about 5 nm. Increasing time and temperature of the synthesis reaction resulted in photoluminescence intensification. PL spectroscopy helped understanding the adsorption kinetics of oxygen on ZnS nanoparticles during the precipitation synthesis process. Fabrication of ZnS structures with appropriate oxygen adsorption capacity was suggested as a means of PL emission intensity control.

  18. Cytotoxicity of Biologically Synthesized Silver Nanoparticles in MDA-MB-231 Human Breast Cancer Cells

    OpenAIRE

    Sangiliyandi Gurunathan; Jae Woong Han; Vasuki Eppakayala; Muniyandi Jeyaraj; Jin-Hoi Kim

    2013-01-01

    Silver nanoparticles (AgNPs) have been used as an antimicrobial and disinfectant agents. However, there is limited information about antitumor potential. Therefore, this study focused on determining cytotoxic effects of AgNPs on MDA-MB-231 breast cancer cells and its mechanism of cell death. Herein, we developed a green method for synthesis of AgNPs using culture supernatant of Bacillus funiculus, and synthesized AgNPs were characterized by various analytical techniques such as UV-visible spe...

  19. Preparation of transition metal nanoparticles and surfaces modified with (co)polymers synthesized by RAFT

    Science.gov (United States)

    McCormick, III, Charles L.; Lowe, Andrew B.; Sumerlin, Brent S.

    2011-12-27

    A new, facile, general one-phase method of generating thiol-functionalized transition metal nanoparticles and surfaces modified by (co)polymers synthesized by the RAFT method is described. The method includes the steps of forming a (co)polymer in aqueous solution using the RAFT methodology, forming a colloidal transition metal precursor solution from an appropriate transition metal; adding the metal precursor solution or surface to the (co)polymer solution, adding a reducing agent into the solution to reduce the metal colloid in situ to produce the stabilized nanoparticles or surface, and isolating the stabilized nanoparticles or surface in a manner such that aggregation is minimized. The functionalized surfaces generated using these methods can further undergo planar surface modifications, such as functionalization with a variety of different chemical groups, expanding their utility and application.

  20. A sol-gel method to synthesize indium tin oxide nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Xiuhua Li; Xiujuan xu; Xin Yin; Chunzhong Li; Jianrong Zhang

    2011-01-01

    Transparent conductive indium tin oxide (ITO) nanoparticles were synthesized by a novel sol-gel method.Granulated indium and tin were dissolved in HNO3 and partially complexed with citric acid.A sol-gel process was induced when tertiary butyl alcohol was added dropwise to the above solution.ITO nanoparticles with an average crystallite size of 18.5 nm and surface area of 32.6 m2/g were obtained after the gel was heat-treated at 700 C.The ITO nanoparticles showed good sinterability,the starting sintering temperature decreased sharply to 900 C,and the 1400 C sintered pellet had a density of 98.1 % of theoretical density (TD).

  1. Cytotoxic effect of silver nanoparticles synthesized from Padina tetrastromatica on breast cancer cell line

    Science.gov (United States)

    Gnana Selvi, B. Clara; Madhavan, J.; Santhanam, Amutha

    2016-09-01

    In recent years researchers were attracted towards marine sources due to the presence of active components in it. Seaweeds were widely used in pharmaceutical research for their known biological activities. The biological synthesis method of silver nanoparticles (AgNPs) using Padina tetrastromatica seaweed extract and their cytotoxicity against breast cancer MCF-7 cells was reported in this study. The synthesized AgNPs using seaweed extract were subjected to x-ray diffraction, UV–visible spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscope, energy dispersive x-ray, zeta potential to elucidate the structural, morphology, size as well as surface potential parameters. An absorption peak at 430 nm in UV-visible spectrum reveals the excitation and surface plasmon resonance of AgNPs. FE-SEM micrographs exhibits the biosynthesized AgNPs, which are pre-dominantly round shaped and the size ranges between 40–50 nm. The zeta potential value of ‑27.6 mV confirms the stable nature of biosynthesized silver nanoparticles. Furthermore, the biological synthesized Ag NPs exhibited a dose-dependent cytotoxicity against human breast cancer cell (MCF-7) and the inhibitory concentration (IC50) was found for AgNPs against MCF-7 at 24 h incubation. Biological method of synthesizing silver nanoparticles shows a environmental friendly property which helps in effective electrifying usage in many fields.

  2. Cytotoxic effect of silver nanoparticles synthesized from Padina tetrastromatica on breast cancer cell line

    Science.gov (United States)

    Gnana Selvi, B. Clara; Madhavan, J.; Santhanam, Amutha

    2016-09-01

    In recent years researchers were attracted towards marine sources due to the presence of active components in it. Seaweeds were widely used in pharmaceutical research for their known biological activities. The biological synthesis method of silver nanoparticles (AgNPs) using Padina tetrastromatica seaweed extract and their cytotoxicity against breast cancer MCF-7 cells was reported in this study. The synthesized AgNPs using seaweed extract were subjected to x-ray diffraction, UV-visible spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscope, energy dispersive x-ray, zeta potential to elucidate the structural, morphology, size as well as surface potential parameters. An absorption peak at 430 nm in UV-visible spectrum reveals the excitation and surface plasmon resonance of AgNPs. FE-SEM micrographs exhibits the biosynthesized AgNPs, which are pre-dominantly round shaped and the size ranges between 40-50 nm. The zeta potential value of -27.6 mV confirms the stable nature of biosynthesized silver nanoparticles. Furthermore, the biological synthesized Ag NPs exhibited a dose-dependent cytotoxicity against human breast cancer cell (MCF-7) and the inhibitory concentration (IC50) was found for AgNPs against MCF-7 at 24 h incubation. Biological method of synthesizing silver nanoparticles shows a environmental friendly property which helps in effective electrifying usage in many fields.

  3. Catalytic Activity of Mono- and Bi-Metallic Nanoparticles Synthesized via Microemulsions

    Directory of Open Access Journals (Sweden)

    Ramona Y.G. König

    2014-07-01

    Full Text Available Water-in-oil (w/o microemulsions were used as a template for the synthesis of mono- and bi-metallic nanoparticles. For that purpose, w/o-microemulsions containing H2PtCl6, H2PtCl6 + Pb(NO32 and H2PtCl6 + Bi(NO3, respectively, were mixed with a w/o-microemulsion containing the reducing agent, NaBH4. The results revealed that it is possible to synthesize Pt, PtPb and PtBi nanoparticles of ~3–8 nm in diameter at temperatures of about 30°C. The catalytic properties of the bimetallic PtBi and PtPb nanoparticles were studied and compared with monometallic platinum nanoparticles. Firstly, the electrochemical oxidation of formic acid to carbon monoxide was investigated, and it was found that the resistance of the PtBi and PtPb nanoparticles against the catalyst-poisoning carbon monoxide was significantly higher compared to the Pt nanoparticles. Secondly, investigating the reduction of 4-nitrophenol to 4-aminophenol,we found that the bimetallic NPs are most active at 23 °C, while the order of the activity changes at higher temperatures, i.e., that the Pt nanoparticles are the most active ones at 36 and 49 °C. Furthermore, we observed a strong influence of the support, which was either a polymer or Al2O3. Thirdly, for the hydrogenation of allylbenzene to propylbenzene, the monometallic Pt NPs turned out to be the most active catalysts, followed by the PtPb and PtBi NPs. Comparing the two bimetallic nanoparticles, one sees that the PtPb NPs are significantly more active than the respective PtBi NPs.

  4. Synthesizing Zno Nanoparticles by High-Energy Milling and Investigating Their Antimicrobial Effect

    Directory of Open Access Journals (Sweden)

    N Mohammadi

    2015-07-01

    Results: The study results demonstrated that size of the synthesized nanoparticles was within the range of 20 -90 nm and their morphology was reported as nanorod and nanoparticles with multifaceted cross-section. An increase in the density of nanoparticles resulted in a rise in the antimicrobial effect. Moreover, Staphylococcus aureus bacteria inhibition zone was 3±0.5 and 7±0.5 mm respectively at the density of 6 and 10 mM. The MIC and MBC of ZnO nanoparticles provided for Staphylococcus aureus were observed 3±3 and 2.5±0 mg/ml, whereas they were reported 7.5±0 and 8±0 mg/ml for Escherichia coli bacteria. Conclusion: The findings of the present study revealed that ZnO nanomaterials could be synthesized by applying high-energy milling on micron-scaled ZnO particles. In addition, they can be utilized in food packaging and preservation process.

  5. Mechanistic aspects of biologically synthesized silver nanoparticles against food- and water-borne microbes.

    Science.gov (United States)

    Krishnaraj, Chandran; Harper, Stacey L; Choe, Ho Sung; Kim, Kwang-Pyo; Yun, Soon-Il

    2015-10-01

    In the present study, silver nanoparticles (AgNPs) synthesized from aqueous leaves extract of Malva crispa and their mode of interaction with food- and water-borne microbes were investigated. Formation of AgNPs was conformed through UV-Vis, FE-SEM, EDS, AFM, and HR-TEM analyses. Further the concentration of silver (Ag) in the reaction mixture was conformed through ICP-MS analysis. Different concentration of nanoparticles (1-3 mM) tested to know the inhibitory effect of bacterial pathogens such as Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhi, Salmonella enterica and the fungal pathogens of Penicillium expansum, Penicillium citrinum, Aspergillus oryzae, Aspergillus sojae and Aspergillus niger. Interestingly, nanoparticles synthesized from 2 to 3 mM concentration of AgNO3 showed excellent inhibitory activities against both bacterial and fungal pathogens which are well demonstrated through well diffusion, poison food technique, minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC). In addition, mode of interaction of nanoparticles into both bacterial and fungal pathogens was documented through Bio-TEM analysis. Further the genomic DNA isolated from test bacterial strains and their interaction with nanoparticles was carried out to elucidate the possible mode of action of nanoparticles against bacteria. Interestingly, AgNPs did not show any genotoxic effect against all the tested bacterial strains which are pronounced well in agarose gel electrophoresis and for supporting this study, UV-Vis and Bio-TEM analyses were carried out in which no significant changes observed compared with control. Hence, the overall results concluded that the antimicrobial activity of biogenic AgNPs occurred without any DNA damage. PMID:26178241

  6. Magnetic and Moessbauer spectroscopic studies of NiZn ferrite nanoparticles synthesized by a combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Sreeja, V.; Vijayanand, S.; Deka, S.; Joy, P. A., E-mail: pa.joy@ncl.res.in [National Chemical Laboratory, Physical and Materials Chemistry Division (India)

    2008-04-15

    The properties of nanocrystalline Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} synthesized by an auto-combustion method have been investigated by magnetic measurements and Moessbauer spectroscopy. The as-synthesized single phase nanosized ferrite powder is annealed at different temperatures in the range 673-1,273 K to obtain nanoparticles of different sizes. The powders are characterized by powder X-ray diffraction, vibrating sample magnetometer, transmission electron microscopy and Moessbauer spectroscopy. The as-synthesized powder with average particle size of {approx}9 nm is superparamagnetic. Magnetic transition temperature increases up to 665 K for the nanosized powder as compared to the transition temperature of 548 K for the bulk ferrite. This has been confirmed as due to the abnormal cation distribution, as evidenced from room temperature Moessbauer spectroscopic studies.

  7. Enhanced antibacterial activity of zinc oxide nanoparticles synthesized using Petroselinum crispum extracts

    International Nuclear Information System (INIS)

    The present contribution reports the synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous leaf and root extracts of Petroselinum crispum (parsley) and characterization of as-prepared samples. ZnO NPs are subjected to X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR) studies. The XRD studies reveal a hexagonal wurtzite structure without supplementary diffraction lines for all ZnO samples. TEM analysis shows that the particle size is influenced by the type of plant extract. The EPR spectra indicate the presence of Mn2+ ions in ZnO sample synthesized using P. crispum leaf extract, while zinc vacancy complexes and oxygen vacancies are evidenced in all analyzed samples. ZnO NPs synthesized using P. crispum extracts exhibit increased (2-16 times) antibacterial activity as compared to chemically synthesized ZnO NPs

  8. Enhanced antibacterial activity of zinc oxide nanoparticles synthesized using Petroselinum crispum extracts

    Energy Technology Data Exchange (ETDEWEB)

    Stan, Manuela, E-mail: manuela.stan@itim-cj.ro; Popa, Adriana; Toloman, Dana; Silipas, Teofil-Danut [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca (Romania); Vodnar, Dan Cristian [University of Agricultural Sciences and Veterinary Medicine, Department of Food Science and Technology, 3-5 Manastur Street, 400372 Cluj-Napoca (Romania); Katona, Gabriel [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, 400028 Cluj-Napoca (Romania)

    2015-12-23

    The present contribution reports the synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous leaf and root extracts of Petroselinum crispum (parsley) and characterization of as-prepared samples. ZnO NPs are subjected to X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR) studies. The XRD studies reveal a hexagonal wurtzite structure without supplementary diffraction lines for all ZnO samples. TEM analysis shows that the particle size is influenced by the type of plant extract. The EPR spectra indicate the presence of Mn{sup 2+} ions in ZnO sample synthesized using P. crispum leaf extract, while zinc vacancy complexes and oxygen vacancies are evidenced in all analyzed samples. ZnO NPs synthesized using P. crispum extracts exhibit increased (2-16 times) antibacterial activity as compared to chemically synthesized ZnO NPs.

  9. Structural and Morphological Properties of Cr2O3 Nanoparticles Synthesized By Novel Solvent Free Method

    Directory of Open Access Journals (Sweden)

    Meenambika .R

    2014-02-01

    Full Text Available Nanoparticles of chromium oxide (Cr2O3 are widely used in many fields serving as catalysts, wear resistance materials, and advanced colorants. For the first time, we have reported the solvent free synthesis of Cr2O3 nanoparticles via microwave irradiation followed by calcinations at 200, 400, 600 and 800°C for 1h. The influence of calcination temperature on the particle size, microstructure and morphology was examined by X-ray diffraction, Scanning Electron Microscope (SEM and Transmission Electron Microscope (TEM, Elemental compositions have been estimated by energy dispersive X-ray Absorption EDAX and thermo gravimetrv analysis (TGA-DTA. The average particle size of the synthesized Cr2O3 nanoparticles is calculated using the Scherrer's formula and found to be of less than 60 nm and is compared with Williamson Hall method . It is found that the molar ratio 1:3 is considered to be the best proportion to synthesis Cr2O3nanoparticles. These results also indicate that there is an improvement in the crystallinity of Cr2O3 nanoparticles with the increase in the annealing temperature. As the process is simple and low-cost, it has the potential to be produced on a large scale.

  10. A simple aqueous electrochemical method to synthesize TiO₂ nanoparticles.

    Science.gov (United States)

    Bezares, Ivan; del Campo, Adolfo; Herrasti, Pilar; Muñoz-Bonilla, Alexandra

    2015-11-21

    Here, a simple and rapid electrochemical approach to synthesize TiO2 nanoparticles in aqueous solution is reported. This method consists in the electro-oxidation of titanium foil in a tetrabutylammonium bromide aqueous solution, which acts as both an electrolyte and a surfactant. Amorphous TiO2 particles in the nanoscale (∼5 nm), well dispersed in aqueous solution, were directly formed by applying low current densities in a short reaction time. It was demonstrated that several experimental parameters influence the reaction yield; an increase in the current, temperature and reaction time augments the quantity of the obtained material. Then, the amorphous nanoparticles were completely crystallized into a pure anatase phase by thermal treatment under an air atmosphere as analyzed by X-ray diffraction and Raman spectroscopy. Besides, the size of the nanoparticles increased to approximately 12 nm in the calcination process. The band gap energies of the resulting TiO2 anatase nanoparticles were determined by diffuse reflectance measurements according to the Kubelka Munk theory, revealing low values between 2.95 and 3.10 eV. Therefore, the results indicate the success of this method to create TiO2 nanoparticles in aqueous medium with good optical properties. PMID:26469391

  11. X-ray synthesized PEGylated (polyethylene glycol coated) gold nanoparticles in mice strongly accumulate in tumors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chang-Hai [Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan (China); Liu, Chi-Jen, E-mail: cjliuc@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan (China); Chien, Chia-Chi [Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Chen, Hsin-Tai; Hua, Tzu-En; Leng, Wei-Hua; Chen, Hsiang-Hsin; Kempson, Ivan M. [Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan (China); Hwu, Y., E-mail: phhwu@sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Institute of Optoelectronic Science, National Taiwan Ocean University, Keelung 202, Taiwan (China); Hsiao, Michael; Lai, Tsung-Ching; Wang, J.L. [Genomic Research Center, Academia Sinica, Nankang, Taipei 115, Taiwan (China); Yang, Chung-Shi [Center for Nanomedicine, National Health Research Institutes, Miaoli 350, Taiwan (China); Lin, Hong-Ming [Department of Materials Engineering, Tatung University, Taipei 115, Taiwan (China); Chen, Yu-Jen [Department of Radiation Oncology and Medical Research, Mackay Memorial Hospital, Taipei 251, Taiwan (China); Margaritondo, G. [Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2011-03-15

    Research highlights: {yields} PEG coated Au nanoparticles synthesized by intense X-rays. {yields} PEG-Au nanoparticles accumulate up to {approx}25 times in tumor regions more than in normal muscle tissue. {yields} The accumulation increases with the time after injection for up to {approx}12 h in tumor. - Abstract: The spatial distribution of X-ray synthesized, PEG coated Au nanoparticles in cancer-bearing mice and their time dependent accumulation were investigated with inductive coupled plasma - optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM) and histological imaging. The results conclusively demonstrate that the particles strongly accumulate in tumor regions; up to {approx}25 times more than in normal muscle tissue. This accumulation increases with the time after injection for up to {approx}12 h in tumor, spleen and liver tissues, whereas for most non-tumor regions it saturates or decreases (blood, lung, brain, heart, and kidney). The impact of this result is discussed with special emphasis on passive targeted drug delivery and could also be used for the delineation and early-stage imaging of small tumors.

  12. Synthesis, Characterization and Antimicrobial Activity of Zinc Oxide Nanoparticles Synthesized From Calotropis procera

    Directory of Open Access Journals (Sweden)

    Poovizhi. J

    2015-09-01

    Full Text Available The aim of the study was to compare the yield, nature and antimicrobial activity of nanoparticles synthesized using Calotropis procera leaf extract. ZnO NPs synthesized were characterized by FTIR and SEM. It was evident from SEM images that the size of the particles obtained by biological method is ranging from 100-200 nm. Antibacterial study was carried out on human bacterial and plant bacterial pathogens and their MIC values were determined. The antibacterial activity towards human bacterial and plant pathogen showed good sensitivity towards the green synthesized ZnO NP’s at all concentrations and maximum zone of inhibition occurred at the concentration of 30μg/mL. Minimum Inhibitory concentrations of NPs against human pathogenic bacteria and plant bacterial pathogens, shows that all tested microorganisms were completely inhibited at the concentration of 50 to 12.5μg/ml of nano-ZnO. The antifungal activity of ZnO NPs against fungi shows that different concentration of ZnO nanoparticles caused significant inhibition in the spore germination.

  13. Screening of zinc oxide nanoparticles for cell proliferation synthesized through Adhatoda vasica nees

    Directory of Open Access Journals (Sweden)

    G. Bhumi

    2014-06-01

    Full Text Available Nano science is the basic Study of systems and materials at the nanoscale. The objective of the present study focuses on the Phytoconstituent mediated biological synthesis of ZnO-NPs by Zinc acetate and sodium hydroxide by utilizing the biocomponents of leaves of Adhatoda vasica .The samples are characterized by UV-Vis Spectroscopy, Scanning Electron Microscopy (SEM, Energy Dispersive Xray (EDAX, X-ray diffraction (XRD and FT-Raman Spectroscopy. The Synthesized ZnO-NPs were found to be discoid in Shape with an average size of 19 - 60 nm .The diffraction pattern also confirmed that the higher percentage of ZnO with fine particle size. Phytochemicals present in the plant were responsible for the quick reduction of Zn+ ion to metallic Zinc Oxide nanoparticles. The synthesized ZnO-NPs had the potential to mitigate the bacterial cell proliferation particularly Escherichia coli, Bacillus thuringiensis, Pseudomonas aeurogonisa and Staphylococcus aureus. Adhatoda vasica is a good source for rapid reduction of metallic Zinc oxide in to nanoparticles with antibacterial activity. These green synthesized ZnO-NPs are possess therapeutic values.

  14. Extensive Characterization of Oxide-Coated Colloidal Gold Nanoparticles Synthesized by Laser Ablation in Liquid

    Directory of Open Access Journals (Sweden)

    Romuald Intartaglia

    2016-09-01

    Full Text Available Colloidal gold nanoparticles are a widespread nanomaterial with many potential applications, but their aggregation in suspension is a critical issue which is usually prevented by organic surfactants. This solution has some drawbacks, such as material contamination and modifications of its functional properties. The gold nanoparticles presented in this work have been synthesized by ultra-fast laser ablation in liquid, which addresses the above issues by overcoating the metal nanoparticles with an oxide layer. The main focus of the work is in the characterization of the oxidized gold nanoparticles, which were made first in solution by means of dynamic light scattering and optical spectroscopy, and then in dried form by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and finally by surface potential measurements with atomic force microscopy. The light scattering assessed the nanoscale size of the formed particles and provided insight in their stability. The nanoparticles’ size was confirmed by direct imaging in transmission electron microscopy, and their crystalline nature was disclosed by X-ray diffraction. The X-ray photoelectron spectroscopy showed measurements compatible with the presence of surface oxide, which was confirmed by the surface potential measurements, which are the novel point of the present work. In conclusion, the method of laser ablation in liquid for the synthesis of gold nanoparticles has been presented, and the advantage of this physical approach, consisting of coating the nanoparticles in situ with gold oxide which provides the required morphological and chemical stability without organic surfactants, has been confirmed by using scanning Kelvin probe microscopy for the first time.

  15. Curved wall-jet burner for synthesizing titania and silica nanoparticles

    KAUST Repository

    Ismail, Mohamed

    2015-01-01

    A novel curved wall-jet (CWJ) burner was designed for flame synthesis, by injecting precursors through a center tube and by supplying fuel/air mixtures as an annular-inward jet for rapid mixing of the precursors in the reaction zone. Titanium dioxide (TiO2) and silicon dioxide (SiO2) nanoparticles were produced in ethylene (C2H4)/air premixed flames using titanium tetraisopropoxide (TTIP) and hexamethyldisiloxane (HMDSO) as the precursors, respectively. Particle image velocimetry measurements confirmed that the precursors can be injected into the flames without appreciably affecting flow structure. The nanoparticles were characterized using X-ray diffraction, Raman spectroscopy, the Brunauer-Emmett-Teller (BET) method, and high-resolution transmission electron microscopy. In the case of TiO2, the phase of nanoparticles could be controlled by adjusting the equivalence ratio, while the particle size was dependent on the precursor loading rate and the flame temperature. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence ratios (φ > 1.3). In the case of SiO2, the particle size could be controlled from 11 to 18 nm by adjusting the precursor loading rate. © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  16. Magnetic nanoparticles for biophysical applications synthesized by high-power physical dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Safronov, A.P., E-mail: safronov@iep.uran.ru [Ural Federal University, Yekaterinburg (Russian Federation); Beketov, I.V. [Ural Federal University, Yekaterinburg (Russian Federation); Institute of Elecrophysics, Ural branch of RAS, Yekaterinburg (Russian Federation); Tyukova, I.S. [Ural Federal University, Yekaterinburg (Russian Federation); Medvedev, A.I. [Ural Federal University, Yekaterinburg (Russian Federation); Institute of Elecrophysics, Ural branch of RAS, Yekaterinburg (Russian Federation); Samatov, O.M.; Murzakaev, A.M. [Institute of Elecrophysics, Ural branch of RAS, Yekaterinburg (Russian Federation)

    2015-06-01

    The low cost and high output methods of high-power physical dispersion: the electrical explosion of wire and the laser target evaporation were elaborated for the production of iron oxide magnetic nanoparticles (MNPs) with controlled dispersion parameters and highly reproducible functional properties. The synthesized MNPs were spherical in shape with mean diameter 10 nm and lognormal particle size distribution. The phase composition, shape, particle size and functional properties of MNPs were cross-examined by a variety of contemporary experimental techniques. The phase structure of MNPs corresponds to the inverse spinel of magnetite. Meanwhile, due to the non-equilibrium conditions of the dispersion chemical composition of MNPs is close to maghemite—γ-Fe{sub 2}O{sub 3}. Their magnetic properties are reproducible and very close to the single domain superparamagnetic behavior. The stability of the suspensions of these MNPs and their applicability in the biophysical purposes such as magneto-induced heating have been demonstrated. - Highlights: • We present two methods of low-cost and high output production of iron oxide nanoparticles. • We obtained 10 nm spherical maghemite nanoparticles with close to superparamagnetic behavior. • The suspensions of obtained nanoparticles are stable to salt in physiological concentration. • Magneto-induced heating of suspensions fits well with the theoretical predictions.

  17. Au, Ag and Au:Ag colloidal nanoparticles synthesized by pulsed laser ablation as SERS substrates

    Directory of Open Access Journals (Sweden)

    M. Vinod

    2014-12-01

    Full Text Available Chemically pure colloidal suspensions of gold and silver nanoparticles were synthesized using pulsed laser ablation. The dependence of laser fluence on the surface plasmon characteristics of the nanoparticles was investigated. Au:Ag colloidal suspensions were prepared by mixing highly monodisperse Au and Ag nanocolloids. The plasmon band of these mixtures was found to be highly sensitive to Au:Ag concentration ratio and wavelength of the laser beam used in the ablation process. The Au:Ag mixture consists of almost spherical shaped nanostructures with a tendency to join with adjacent ones. The surface enhanced Raman scattering activity of the Au, Ag and Au:Ag colloidal suspensions was tested using crystal violet as probe molecules. Enhancement in Raman signal obtained with Au:Ag substrates was found to be promising and strongly depends on its plasmon characteristics.

  18. Au, Ag and Au:Ag colloidal nanoparticles synthesized by pulsed laser ablation as SERS substrates

    Institute of Scientific and Technical Information of China (English)

    M. Vinod; K.G.Gopchandran

    2014-01-01

    Chemically pure colloidal suspensions of gold and silver nanoparticles were synthesized using pulsed laser ablation. The dependence of laser fluence on the surface plasmon characteristics of the nanoparticles was investigated. Au:Ag colloidal suspensions were prepared by mixing highly monodisperse Au and Ag nanocolloids. The plasmon band of these mixtures was found to be highly sensitive to Au:Ag concentration ratio and wavelength of the laser beam used in the ablation process. The Au:Ag mixture consists of almost spherical shaped nanostructures with a tendency to join with adjacent ones. The surface enhanced Raman scattering activity of the Au, Ag and Au:Ag colloidal suspensions was tested using crystal violet as probe molecules. Enhancement in Raman signal obtained with Au:Ag substrates was found to be promising and strongly depends on its plasmon characteristics.

  19. Adsorption of Reactive Black 5 on Synthesized Titanium Dioxide Nanoparticles: Equilibrium Isotherm and Kinetic Studies

    Directory of Open Access Journals (Sweden)

    Majeed A. Shaheed

    2014-01-01

    Full Text Available The synthesized titanium dioxide nanoparticles (TiO2-NPs were used as adsorbent to remove reactive black 5 (RB 5 in aqueous solution. Various factors affecting adsorption of RB 5 aqueous solutions such as pH, initial concentration, contact time, dose of nanoparticles, and temperature were analyzed at fixed solid/solution ratio. Langmuir and Freundlich isotherms were used as model adsorption equilibrium data. Langmuir isotherm was found to be the most adequate model. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to describe the adsorption kinetics. The experimental data was fitted to pseudo-second-order kinetics. The thermodynamic parameters such as Gibbs-free energy, enthalpy, and entropy changes were determined. These parameters indicated the endothermic and spontaneity nature of the adsorption. The results demonstrated the fact that the TiO2-NPs are promising adsorbent for the removal of RB 5 from aqueous solutions.

  20. Orientation relationship in WC-Co composite nanoparticles synthesized by in situ reactions

    International Nuclear Information System (INIS)

    Using the nanoscale violet tungsten oxide as the tungsten source, the WC-Co composite powder was synthesized by the in situ reactions. The particle size of the WC-Co composite powder has a narrow distribution with the mean particle size below 100 nm, and the single composite particle has a nanocrystalline structure with a mean grain size smaller than 10 nm. The detailed characterizations of the nanoparticle microstructure reveal that the orientation relationship and coherence at the interfaces can form during the in situ reactions and further inherit in the consolidated cemented carbide bulk material. The favorable crystallographic characteristics of the WC-Co composite nanoparticles play a significant role in the enhancement of the mechanical properties of the prepared cemented carbide bulk material. (paper)

  1. Orientation relationship in WC-Co composite nanoparticles synthesized by in situ reactions

    Science.gov (United States)

    Wang, Xilong; Song, Xiaoyan; Liu, Xuemei; Liu, Xingwei; Wang, Haibin; Zhou, Cheng

    2015-04-01

    Using the nanoscale violet tungsten oxide as the tungsten source, the WC-Co composite powder was synthesized by the in situ reactions. The particle size of the WC-Co composite powder has a narrow distribution with the mean particle size below 100 nm, and the single composite particle has a nanocrystalline structure with a mean grain size smaller than 10 nm. The detailed characterizations of the nanoparticle microstructure reveal that the orientation relationship and coherence at the interfaces can form during the in situ reactions and further inherit in the consolidated cemented carbide bulk material. The favorable crystallographic characteristics of the WC-Co composite nanoparticles play a significant role in the enhancement of the mechanical properties of the prepared cemented carbide bulk material.

  2. Study on antibacterial activity of silver nanoparticles synthesized by gamma irradiation method using different stabilizers

    OpenAIRE

    Van Phu, Dang; Quoc, Le Anh; Duy, Nguyen Ngoc; Lan, Nguyen Thi Kim; Du, Bui Duy; Luan, Le Quang; Hien, Nguyen Quoc

    2014-01-01

    Colloidal solutions of silver nanoparticles (AgNPs) were synthesized by gamma Co-60 irradiation using different stabilizers, namely polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), alginate, and sericin. The particle size measured from TEM images was 4.3, 6.1, 7.6, and 10.2 nm for AgNPs/PVP, AgNPs/PVA, AgNPs/alginate, and AgNPs/sericin, respectively. The influence of different stabilizers on the antibacterial activity of AgNPs was investigated. Results showed that AgNPs/alginate exhibite...

  3. Antibacterial and Photocatalytic Activities of ZnO Nanoparticles: Synthesized Using Water Melon Juice as Fuel

    Science.gov (United States)

    Yadav, L. S. Reddy; Kumar, Danith; Kavitha, C.; Rajanaika, H.; Prasad, B. Daruka; Nagabhushana, H.; Nagaraju, G.

    2016-02-01

    In the present work, Zinc Oxide nanoparticles (ZnO Nps) have been prepared by a simple and low temperature solution combustion method using Zinc nitrate as a precursor and solid water melon juice as a novel fuel for the first time. The structure and morphology of the synthesized ZnO NPs have been analyzed using various analytical techniques such as Powder X-ray diffraction, FTIR spectroscopy, Raman spectroscopy, UV-Visible spectroscopy, photoluminescence spectroscopy, scanning electron microscope and transmission electron microscope. ZnO NPs show good photo catalytic activity for the degradation of methylene blue (MB) dye. It also shows significant antibacterial activities against three bacterial strains.

  4. Large CZTS Nanoparticles Synthesized by Hot-Injection for Thin Film Solar Cells.

    OpenAIRE

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    2015-01-01

    The kesterite material, Cu2ZnSn(SxSe1-x)4 (CZTS), shows great promise as the absorber layer for future thin film solar cells. Solution processing allows for comparatively fast and inexpensive fabrication, and holds the record efficiency in the kesterite family. However, for nanoparticle (NP) solution processing to be a feasible fabrication route, the amount of carbon in the film has to be limited. In our work, we try to limit the organic material in the film by synthesizing larger NPs. Larger...

  5. Antiproliferative effect of silver nanoparticles synthesized using amla on Hep2 cell line

    Institute of Scientific and Technical Information of China (English)

    Fathima Stanley Rosarin; Vadivel Arulmozhi; Samuthira Nagarajan; Sankaran Mirunalini

    2013-01-01

    Objective: To synthesize silver nanoparticles by amla extract, screen the cytotoxic, oxidative stress and apoptotic effect of silver nanoparticles (AgNPs) on Hep2 cell line (laryngeal carcinoma cells) in vitro, and to compare the effect of Phyllanthus emblica (P. emblica) (amla) with AgNPs synthesized by amla and 5-FU. Methods: AgNPs was synthesized by P. emblica (aqueous extract) and nanoparticles were characterized UV-Vis spec, the presence of biomoloecules of amla capped in AgNPs was found by FT-IR analysis, shape and size were examined by SEM and DLS. Cytotoxicity of experimental drugs was tested to find IC50 value. ROS generation in cells have been measured by DCFH-DA staining, AO-EtBr, Rhodamine-123 staining and DNA fragmentation were performed to assess apoptotic cell death, mitochondrial membrane potential and apoptotic DNA damage, respectively. Oxidative stress was analyzed by measuring lipid peroxides and antioxidants level to understand the cancer cell death by pro-oxidant mechanism.Results:PE-AgNPs was synthesized and confirmed through kinetic behavior of NPs. The shape of PE-AgNPs was spherical and cubic since it was agglomerated, and the nanoparticle surface was complicated. Average particle size distribution of PE-AgNPs was found to be 188 nm. Potent biomolecules of P. emblica such as polyphenols were capped with AgNPs and reduced its toxicity. In cytotoxicity assay the concentration in which the maximum number of cell death was 60 μg/mL and 50 μg/mL for P. emblica (alone) and AgNPs, respectively and IC50 values were fixed as 30 μg/mL and 20 μg/mL. ROS generation, apoptotic morphological changes, mitochondrial depolarization, DNA damage and oxidative stress was observed as more in AgNPs treated cells than in P. emblica (30 μg/mL) (alone) treated cells and 5-FU treated cells gave similar result.Conclusions:The results suggest that the AgNPs are capped with biomolecules of amla enhanced cytotoxicity in laryngeal cancer cells through oxidative

  6. Acaricidal activity of synthesized titanium dioxide nanoparticles using Calotropis gigantea against Rhipicephalus microplus and Haemaphysalis bispinosa

    Institute of Scientific and Technical Information of China (English)

    Sampath Marimuthu; Moorthy Iyappan; Chinnadurai Siva; Loganathan Karthik; Kokati Venkata Bhaskara Rao; Abdul Abdul Rahuman; Chidambaram Jayaseelan; Arivarasan Vishnu Kirthi; Thirunavukkarasu Santhoshkumar; Kanayairam Velayutham; Asokan Bagavan; Chinnaperumal Kamaraj; Gandhi Elango

    2013-01-01

    Objective: To assess the acaricidal activity of titanium dioxide nanoparticles (TiO2 NPs) synthesized from flower aqueous extract of Calotropis gigantea (C. gigantea) against the larvae of Rhipicephalus (Boophilus) microplus [R. (B.) microplus] and the adult of Haemaphysalis bispinosa (H. bispinosa). Methods: The lyophilized C. gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH)2 (10 mM) and magnetically stirred for 6 h. Synthesized TiO2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Energy dispersive X-ray spectroscopy (EDX). The synthesised TiO2 NPs were tested against the larvae of R. (B.) microplus and adult of H. bispinosa were exposed to filter paper impregnated method. Results:XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm. The functional groups for synthesized TiO2 NPs were 1 405.19, and 1 053.45 cm-1 for-NH2 bending, primary amines and amides and 1 053.84 and 1 078.45 cm-1 for C-O. SEM micrographs of the synthesized TiO2 NPs showed the aggregated and spherical in shape. The maximum efficacy was observed in the aqueous flower extract of C. gigantea and synthesized TiO2 NPs against R. (B.) microplus (LC50=24.63 and 5.43 mg/L and r2=0.960 and 0.988) and against H. bispinosa (LC50=35.22 and 9.15 mg/L and r2=0.969 and 0.969), respectively. Conclusions: The synthesized TiO2 NPs were highly stable and had significant acaricidal activity against the larvae of R. (B.) microplus and adult of H. bispinosa. This study provides the first report of synthesized TiO2 NPs and possessed excellent anti-parasitic activity.

  7. Studies on Ferromagnetic and Photoluminescence Properties of ITO and Cu-Doped ITO Nanoparticles Synthesized by Solid State Reaction

    Science.gov (United States)

    Babu, S. Harinath; Kaleemulla, S.; Rao, N. Madhusudhana; Krishnamoorthi, C.

    2016-11-01

    Cubic structured indium-tin-oxide (ITO) and copper-doped ITO nanoparticles were synthesized by solid state reaction. The structure, morphology, chemical, magnetic, and photoluminescence properties of the synthesized nanoparticles were studied by x-ray diffraction, field emission scanning electron microscopy, x-ray photoelectron spectroscopy, vibrating sample magnetometry, and photoluminescence spectrophotometry, respectively. Magnetic studies confirmed that the ITO nanoparticles were ferromagnetic at room temperature (300 K) and at 100 K, and it was believed that the observed ferromagnetism may be due to oxygen vacancies and defects present in the system. No hysteresis loop was observed in copper-doped ITO nanoparticles at room temperature and 100 K. The ITO and Cu-doped ITO nanoparticles exhibited two broad emission peaks in the visible region of the electromagnetic spectrum.

  8. Nanometre Ni and core/shell Ni/Au nanoparticles with controllable dimensions synthesized in reverse microemulsion

    Energy Technology Data Exchange (ETDEWEB)

    Chen Dong [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Liu Shuo [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering, Tianjin University, Tianjin 300072 (China); Li Jiajun [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Zhao Naiqin [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)], E-mail: nqzhao@tju.edu.cn; Shi Chunsheng; Du Xiwen; Sheng Jing [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2009-05-05

    Ni nanoparticles with different diameters were chemically synthesized in reverse microemulsion. Furthermore, core/shell Ni/Au nanoparticles with different core diameters and shell thickness were chemically synthesized from the above Ni nanoparticles through an in situ redox-transmetalation method in reverse microemulsion. The X-ray diffraction patterns revealed the presence of crystalline nickel and gold of the core/shell Ni/Au nanoparticles. The spherical Ni nanoparticles and the core/shell structured Ni/Au nanoparticles could be clearly observed by the transmission electron microscope. The diameter of the Ni nanoparticles with narrow size distribution could be controlled to range from about 8 to 30 nm. The diameter of the core/shell Ni/Au nanoparticles could be controlled to range from about 14 to 30 nm, with about 7-21 nm core diameter and about 3-7 nm shell thickness. The ZFC (zero-field-cooled) and FC (field-cooled) curves of the core/shell Ni/Au nanoparticles indicated that the blocking temperature increased from 16 to 53 K as the diameter of the Ni cores increased from about 7 to 15 nm.

  9. Potent antimicrobial and antibiofilm activities of bacteriogenically synthesized gold-silver nanoparticles against pathogenic bacteria and their physiochemical characterizations.

    Science.gov (United States)

    Ramasamy, Mohankandhasamy; Lee, Jin-Hyung; Lee, Jintae

    2016-09-01

    The objective of this study was to develop a bimetallic nanoparticle with enhanced antibacterial activity that would improve the therapeutic efficacy against bacterial biofilms. Bimetallic gold-silver nanoparticles were bacteriogenically synthesized using γ-proteobacterium, Shewanella oneidensis MR-1. The antibacterial activities of gold-silver nanoparticles were assessed on the planktonic and biofilm phases of individual and mixed multi-cultures of pathogenic Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive bacteria (Enterococcus faecalis and Staphylococcus aureus), respectively. The minimum inhibitory concentration of gold-silver nanoparticles was 30-50 µM than that of other nanoparticles (>100 µM) for the tested bacteria. Interestingly, gold-silver nanoparticles were more effective in inhibiting bacterial biofilm formation at 10 µM concentration. Both scanning and transmission electron microscopy results further accounted the impact of gold-silver nanoparticles on biocompatibility and bactericidal effect that the small size and bio-organic materials covering on gold-silver nanoparticles improves the internalization and thus caused bacterial inactivation. Thus, bacteriogenically synthesized gold-silver nanoparticles appear to be a promising nanoantibiotic for overcoming the bacterial resistance in the established bacterial biofilms. PMID:27117745

  10. Evaluation of plant-mediated synthesized silver nanoparticles against vector mosquitoes.

    Science.gov (United States)

    Veerakumar, Kaliyan; Govindarajan, Marimuthu; Hoti, S L

    2014-12-01

    Diseases transmitted by blood-feeding mosquitoes, such as dengue fever, dengue hemorrhagic fever, Japanese encephalitis, malaria, and filariasis, are increasing in prevalence, particularly in tropical and subtropical zones. To control mosquitoes and mosquito-borne diseases, which have worldwide health and economic impacts, synthetic insecticide-based interventions are still necessary, particularly in situations of epidemic outbreak and sudden increases of adult mosquitoes. Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and eco-friendly reducing and capping agents. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Heliotropium indicum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. Adult mosquitoes were exposed to varying concentrations of aqueous extract of H. indicum and synthesized AgNPs for 24 h. AgNPs were rapidly synthesized using the leaf extract of H. indicum, and the formation of nanoparticles was observed within 6 h. The results recorded from UV-vis spectrum, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the adult of A. stephensi (lethal dose (LD)₅₀ = 26.712 μg/mL; LD₉₀ = 49.061 μg/mL), A. aegypti (LD₅₀ = 29.626 μg/mL; LD₉₀ = 54.269 μg/mL), and C. quinquefasciatus (LD₅₀ = 32.077 μg/mL; LD₉₀ = 58.426 μg/mL), respectively. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H.indicum and green synthesis of AgNPs have the potential to be used as an ideal eco-friendly approach for the control of

  11. Evaluation of plant-mediated synthesized silver nanoparticles against vector mosquitoes.

    Science.gov (United States)

    Veerakumar, Kaliyan; Govindarajan, Marimuthu; Hoti, S L

    2014-12-01

    Diseases transmitted by blood-feeding mosquitoes, such as dengue fever, dengue hemorrhagic fever, Japanese encephalitis, malaria, and filariasis, are increasing in prevalence, particularly in tropical and subtropical zones. To control mosquitoes and mosquito-borne diseases, which have worldwide health and economic impacts, synthetic insecticide-based interventions are still necessary, particularly in situations of epidemic outbreak and sudden increases of adult mosquitoes. Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and eco-friendly reducing and capping agents. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Heliotropium indicum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. Adult mosquitoes were exposed to varying concentrations of aqueous extract of H. indicum and synthesized AgNPs for 24 h. AgNPs were rapidly synthesized using the leaf extract of H. indicum, and the formation of nanoparticles was observed within 6 h. The results recorded from UV-vis spectrum, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the adult of A. stephensi (lethal dose (LD)₅₀ = 26.712 μg/mL; LD₉₀ = 49.061 μg/mL), A. aegypti (LD₅₀ = 29.626 μg/mL; LD₉₀ = 54.269 μg/mL), and C. quinquefasciatus (LD₅₀ = 32.077 μg/mL; LD₉₀ = 58.426 μg/mL), respectively. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H.indicum and green synthesis of AgNPs have the potential to be used as an ideal eco-friendly approach for the control of

  12. Effects of ultrasound-related variables on sonochemically synthesized SAPO-34 nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Askari, Sima, E-mail: sima.askari@aut.ac.ir [Faculty of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), P.O. Box 15875-4413, Hafez Ave., Tehran (Iran, Islamic Republic of); Halladj, Rouein, E-mail: halladj@aut.ac.ir [Faculty of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), P.O. Box 15875-4413, Hafez Ave., Tehran (Iran, Islamic Republic of)

    2013-05-01

    The sonochemical method was developed to synthesize uniform SAPO-34 (silicoaluminophosphate molecular sieve) nanoparticles with high crystallinity using TEAOH as a structure-directing agent (SDA). The physicochemical characteristics of SAPO-34 products, i.e. crystallinity, particle size and shape can be controlled by varying the ultrasonic-related variable such as ultrasound power intensity, ultrasonic irradiation time, sonication temperature and geometrical characteristics of the ultrasonic device (e.g., sonotrode size). The products were characterized by XRD, SEM, TEM and BET. It is found that each of the parameters can play a significant role in acoustic cavitation, number of nuclei and the crystal growth. The experimental data establish that the crystallinity is related to ultrasonic intensity and diameter of the sonotrode, as well as sonication temperature. By increasing the ultrasonic power, duration and the sonication temperature, the mean sizes of particles decrease and the morphology of the products efficiently alters from spherical aggregates of cube type SAPO-34 particles to uniform spherical nanoparticles. - Graphical abstract: Increasing US power by increasing either US power intensity or the sonotrode diameter leads to smaller particle size and the morphology changes from spherical aggregates of cubic particles to uniform nanospheres. Highlights: • Effects of ultrasonic parameters on sonochemical synthesis of SAPO-34 nanoparticles. • The higher crystallinity by increasing ultrasonic power, duration and sonication temperature. • The morphology changes from spherical aggregates of cubic particles to uniform nanospheres. • Decreasing the particle size by increasing ultrasonic power, duration and sonication temperature.

  13. Antitumour, antimicrobial and catalytic activity of gold nanoparticles synthesized by different pH propolis extracts

    Energy Technology Data Exchange (ETDEWEB)

    Gatea, Florentina; Teodor, Eugenia Dumitra, E-mail: eu-teodor@yahoo.com [National Institute for Biological Sciences, Centre of Bioanalysis (Romania); Seciu, Ana-Maria [National Institute for Biological Sciences, Cellular and Molecular Biology Department (Romania); Covaci, Ovidiu Ilie [SARA Pharm Solutions (Romania); Mănoiu, Sorin [National Institute for Biological Sciences, Cellular and Molecular Biology Department (Romania); Lazăr, Veronica [University of Bucharest, Faculty of Biology (Romania); Radu, Gabriel Lucian [University “Politehnica” Bucharest, Faculty of Applied Chemistry and Materials Science (Romania)

    2015-07-15

    The Romanian propolis was extracted in five different media, respectively, in water (pH 6.8), glycine buffer (pH 2.5), acetate buffer (pH 5), phosphate buffer (pH 7.4) and carbonate buffer (pH 9.2). The extracts presented different amounts of flavonoids and phenolic acids, increasing pH leading to higher concentrations of active compounds. Five variants of gold nanoparticles suspensions based on different pH Romanian propolis aqueous extracts were successfully synthesized. The obtained nanoparticles presented dimensions between 20 and 60 nm in dispersion form and around 18 nm in dried form, and different morphologies (spherical, hexagonal, triangular). Fourier transform infrared spectroscopy proved the attachment of organic compounds from propolis extracts to the colloidal gold suspensions and X-ray diffraction certified that the suspensions contain metallic gold. The obtained propolis gold nanoparticles do not exhibit any antibacterial or antifungal activity, but presented different catalytic activities and toxicity on tumour cells.

  14. Durable antibacterial and UV protections of in situ synthesized zinc oxide nanoparticles onto cotton fabrics.

    Science.gov (United States)

    Shaheen, Th I; El-Naggar, Mehrez E; Abdelgawad, Abdelrahman M; Hebeish, A

    2016-02-01

    Herein we represent a new discovery based on amine material called hexamethyltriethylene tetramine (HMTETA). We have observed that when an aqueous solution of Zn(NO3)·6H2O was added to aqueous solution of HMTETA followed by shaking for a time, the colorless solution was converted to milky color under the alkaline medium provided by HMTETA prior to formation of uniform zinc oxide nanoparticles (ZnO NPs). The latter are in situ formed within the cotton fabrics without the support of capping or other stabilizing agents. Obviously, then, the new made of formation of ZnO NPs speaks of a single-stage process where cotton fabric is immersed in a prepared solution of the new precursors through which binding of ZnO NPs into the textile fabrics takes place. Textile fabrics are, indeed, used as a template, which is capable of maintaining the size and surface distribution of the as-synthesized nanoparticles in a uniform domain. It is also likely that nanoparticles is confined inside the fibril and microfibrils of the cotton fibers. World-class facilities have been employed to follow up the synthesis of ZnO NPs, their characterization and their application to confer, in particular, high durable antibacterial and UV protective function on cotton fabrics.

  15. Characterization and electrocatalytic properties of sonochemical synthesized PdAg nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Godinez-Garcia, Andres, E-mail: agodinez@qro.cinvestav.mx [Depto. Materiales, Centro de Investigacion y de Estudios Avanzados del IPN, Libramiento norponiente 2000, Fracc. Real de Juriquilla, C.P. 76230 Santiago de Queretaro, Qro. (Mexico); Perez-Robles, Juan Francisco [Depto. Materiales, Centro de Investigacion y de Estudios Avanzados del IPN, Libramiento norponiente 2000, Fracc. Real de Juriquilla, C.P. 76230 Santiago de Queretaro, Qro. (Mexico); Martinez-Tejada, Hader Vladimir [Grupo de Energia y Termodinamica, Universidad Pontificia Bolivariana, Medellin, Antioquia C.P. 050031 (Colombia); Solorza-Feria, Omar [Depto. Quimica, CINVESTAV-IPN, Av. IPN 2508, A. P. 14-740, 07360 D.F. Mexico (Mexico)

    2012-06-15

    High intensity ultrasound was used in the synthesis of PdAg nanoparticles. PdAg nanoparticles were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), scanning transmission electron microscopy (STEM) and high-resolution transmission electron microscopy (HRTEM). Catalytic properties for oxygen reduction reaction (ORR) were determined by electrochemical techniques of cyclic voltammetry (CV) and thin-film rotating disk electrode (TF-RDE). Finally the electrocatalyst was tested as a cathode in a single polymer electrolyte membrane fuel cell (PEMFC). Sonochemical synthesis (SS) decreased the overpotential required for the ORR and increased the double-layer capacitance (DLC) respect to the sodium borohydride reduction method due to a better distribution on vulcan carbon support. The electrocatalytic activity of the nanometric bimetallic electrocatalyst for the ORR in acid media showed a favorable multielectron charge transfer process (n = 4e{sup -}) to water formation. The performance of the membrane electrode assembly (MEA) prepared with dispersed PdAg/C as a cathode catalyst in a single PEMFC is lower in comparison to platinum. - Highlights: Black-Right-Pointing-Pointer Sonochemical synthesized PdAg nanoparticles supported on carbon were produced. Black-Right-Pointing-Pointer The material showed catalytic properties for the oxygen reduction reaction (ORR). Black-Right-Pointing-Pointer The ORR favored the pathway to water formation.

  16. Durable antibacterial and UV protections of in situ synthesized zinc oxide nanoparticles onto cotton fabrics.

    Science.gov (United States)

    Shaheen, Th I; El-Naggar, Mehrez E; Abdelgawad, Abdelrahman M; Hebeish, A

    2016-02-01

    Herein we represent a new discovery based on amine material called hexamethyltriethylene tetramine (HMTETA). We have observed that when an aqueous solution of Zn(NO3)·6H2O was added to aqueous solution of HMTETA followed by shaking for a time, the colorless solution was converted to milky color under the alkaline medium provided by HMTETA prior to formation of uniform zinc oxide nanoparticles (ZnO NPs). The latter are in situ formed within the cotton fabrics without the support of capping or other stabilizing agents. Obviously, then, the new made of formation of ZnO NPs speaks of a single-stage process where cotton fabric is immersed in a prepared solution of the new precursors through which binding of ZnO NPs into the textile fabrics takes place. Textile fabrics are, indeed, used as a template, which is capable of maintaining the size and surface distribution of the as-synthesized nanoparticles in a uniform domain. It is also likely that nanoparticles is confined inside the fibril and microfibrils of the cotton fibers. World-class facilities have been employed to follow up the synthesis of ZnO NPs, their characterization and their application to confer, in particular, high durable antibacterial and UV protective function on cotton fabrics. PMID:26546870

  17. Antitumour, antimicrobial and catalytic activity of gold nanoparticles synthesized by different pH propolis extracts

    International Nuclear Information System (INIS)

    The Romanian propolis was extracted in five different media, respectively, in water (pH 6.8), glycine buffer (pH 2.5), acetate buffer (pH 5), phosphate buffer (pH 7.4) and carbonate buffer (pH 9.2). The extracts presented different amounts of flavonoids and phenolic acids, increasing pH leading to higher concentrations of active compounds. Five variants of gold nanoparticles suspensions based on different pH Romanian propolis aqueous extracts were successfully synthesized. The obtained nanoparticles presented dimensions between 20 and 60 nm in dispersion form and around 18 nm in dried form, and different morphologies (spherical, hexagonal, triangular). Fourier transform infrared spectroscopy proved the attachment of organic compounds from propolis extracts to the colloidal gold suspensions and X-ray diffraction certified that the suspensions contain metallic gold. The obtained propolis gold nanoparticles do not exhibit any antibacterial or antifungal activity, but presented different catalytic activities and toxicity on tumour cells

  18. Microstructure, morphology and magnetic properties of Ni nanoparticles synthesized by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Bouremana, A. [LPM, Faculty of Sciences, USTHB, BP 32, El-Alia, Bab Ezzouar, Algiers (Algeria); Guittoum, A., E-mail: aguittoum@gmail.com [Nuclear Research Centre of Algiers, 02 Bd Frantz Fanon, BP 399, Alger-Gare, Algiers (Algeria); Hemmous, M. [Nuclear Research Centre of Algiers, 02 Bd Frantz Fanon, BP 399, Alger-Gare, Algiers (Algeria); Martínez-Blanco, D. [SCTs, University of Oviedo, EPM, 33600 Mieres (Spain); Gorria, Pedro [Department of Physics & IUTA, EPI, University of Oviedo, 33203 Gijón (Spain); Blanco, J.A. [Department of Physics, University of Oviedo, Calvo Sotelo St., 33007 Oviedo (Spain); Benrekaa, N. [LPM, Faculty of Sciences, USTHB, BP 32, El-Alia, Bab Ezzouar, Algiers (Algeria)

    2015-06-15

    Powder samples containing high purity nickel nanoparticles (NPs) were prepared by hydrothermal method from Ni(II) chloride hexahydrate (NiCl{sub 2}·6H{sub 2}O) under the presence of sodium hydroxide (NaOH) with different concentrations between 5 and 25 mol/L. The synthesis of the NPs occurs through chemical reduction at relatively low temperature (140 °C). The Ni NPs have a face-centred cubic (fcc) crystal structure with a lattice parameter value close to that of pure Ni (a = 3.52 Å). The average crystallite size determined from x-ray diffraction is around 20 nm, except for the sample synthesized under the highest NaOH concentration (25 mol/L), which has the largest average size (>30 nm). The powder morphology at the sub-micrometre length scale looks like agglomerates of Ni-NPs that drastically changes their shape depending on the NaOH concentration, from flower (5 mol/L) to a dendritic-like (25 mol/L). All the samples are ferromagnetic at room temperature with saturation magnetization values between 50 and 52emu/g, and a coercive field that increases with the NaOH concentration from around 135 (5 mol/L) up to 180Oe (25 mol/L). - Highlights: • Pure Nickel nanoparticles have been synthesized by a chemical reaction process. • Different morphologies were observed with the change of NaOH concentration. • The coercive field increases with increasing the NaOH concentration and depends on the shape of nanoparticles.

  19. Characterization of silver nanoparticles synthesized using Urtica dioica Linn. leaves and their synergistic effects with antibiotics

    Directory of Open Access Journals (Sweden)

    Kumari Jyoti

    2016-07-01

    Full Text Available In continuation of the efforts for synthesizing silver nanoparticles (AgNPs by green chemistry route, here we report a facile bottom-up ‘green’ route for the synthesis of AgNPs using aqueous leaves extract of Urtica dioica (Linn.. The synthesized AgNPs were characterized by UV-vis spectroscopy, X-ray diffraction (XRD, Fourier transform-infrared spectroscopy (FTIR, Zeta-sizer and Zeta-potential, Scanning electron microscopy (SEM, Energy dispersive X-ray (EDX spectroscopy, Transmission electron microscopy (TEM and Selected area electron diffraction (SAED. The results obtained from various characterizations revealed that AgNPs were in the size range of 20–30 nm and crystallized in face-centered-cubic structure. The antibacterial activity against Gram-positive (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium bacterial pathogens was demonstrated by synthesized nanoparticles. Further, synergistic effects of AgNPs with various antibiotics were evaluated against above mentioned bacterial pathogens. The results showed that AgNPs in combination with antibiotics have better antibacterial effect as compared with AgNPs alone and hence can be used in the treatment of infectious diseases caused by bacteria. The maximum effect, with a 17.8 fold increase in inhibition zone, was observed for amoxicillin with AgNPs against S. marcescens proving the synergistic role of AgNPs. Therefore, it may be used to augment the activities of antibiotics.

  20. Biochemical analysis of Cassia fistula aqueous extract and phytochemically synthesized gold nanoparticles as hypoglycemic treatment for diabetes mellitus.

    Science.gov (United States)

    Daisy, P; Saipriya, K

    2012-01-01

    Cassia fistula stem bark was used for the preparation of aqueous extract and synthesis of gold nanoparticles to evaluate the hypoglycemic effects of the plant. The synthesized gold nanoparticles were characterized by ultraviolet-visible spectroscopy for their absorbance pattern, Fourier transform infrared spectroscopy to identify possible functional groups, and scanning electron microscopy to determine the size of the nanoparticles. The present investigation reports the efficacy of the gold nanoparticles as promising in the treatment of hyperglycemia. Body weight, serum glucose concentrations, liver function tests, kidney function tests, and lipid profile were analyzed. A significantly larger decrease in serum biochemistry parameters and an increase in body weight, total protein levels, and high-density lipoprotein were observed in rats with streptozotocin-induced diabetes treated with gold nanoparticles than in the ones treated with the aqueous extract. The results of this study confirm that C. fistula gold nanoparticles have promising antidiabetic properties.

  1. Study on antibacterial activity of silver nanoparticles synthesized by gamma irradiation method using different stabilizers

    Science.gov (United States)

    Van Phu, Dang; Quoc, Le Anh; Duy, Nguyen Ngoc; Lan, Nguyen Thi Kim; Du, Bui Duy; Luan, Le Quang; Hien, Nguyen Quoc

    2014-04-01

    Colloidal solutions of silver nanoparticles (AgNPs) were synthesized by gamma Co-60 irradiation using different stabilizers, namely polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), alginate, and sericin. The particle size measured from TEM images was 4.3, 6.1, 7.6, and 10.2 nm for AgNPs/PVP, AgNPs/PVA, AgNPs/alginate, and AgNPs/sericin, respectively. The influence of different stabilizers on the antibacterial activity of AgNPs was investigated. Results showed that AgNPs/alginate exhibited the highest antibacterial activity against Escherichia coli ( E. coli) among the as-synthesized AgNPs. Handwash solution has been prepared using Na lauryl sulfate as surfactant, hydroxyethyl cellulose as binder, and 15 mg/L of AgNPs/alginate as antimicrobial agent. The obtained results on the antibacterial test of handwash for the dilution to 3 mg AgNPs/L showed that the antibacterial efficiency against E. coli was of 74.6%, 89.8%, and 99.0% for the contacted time of 1, 3, and 5 min, respectively. Thus, due to the biocompatibility of alginate extracted from seaweed and highly antimicrobial activity of AgNPs synthesized by gamma Co-60 irradiation, AgNPs/alginate is promising to use as an antimicrobial agent in biomedicine, cosmetic, and in other fields.

  2. Spectroscopic investigations, antimicrobial, and cytotoxic activity of green synthesized gold nanoparticles

    Science.gov (United States)

    Lokina, S.; Suresh, R.; Giribabu, K.; Stephen, A.; Lakshmi Sundaram, R.; Narayanan, V.

    2014-08-01

    The gold nanoparticles (AuNPs) were synthesized by using naturally available Punica Granatum fruit extract as reducing and stabilizing agent. The biosynthesized AuNPs was characterized by using UV-Vis, fluorescence, high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric (TGA) analysis. The surface plasmon resonance (SPR) band at 585 nm confirmed the reduction of auric chloride to AuNPs. The crystalline nature of the biosynthesized AuNPs was confirmed from the HRTEM images, XRD and selected area electron diffraction (SAED) pattern. The HRTEM images showed the mixture of triangular and spherical-like AuNPs having size between 5 and 20 nm. The weight loss of the AuNPs was measured by TGA as a function of temperature under a controlled atmosphere. The biomolecules are responsible for the reduction of AuCl4- ions and the formation of stable AuNPs which was confirmed by FTIR measurement. The synthesized AuNPs showed an excellent antibacterial activity against Candida albicans (ATCC 90028), Aspergillus flavus (ATCC 10124), Staphylococcus aureus (ATCC 25175), Salmonella typhi (ATCC 14028) and Vibrio cholerae (ATCC 14033). The minimum inhibitory concentration (MIC) of AuNPs was recorded against various microorganisms. Further, the synthesized AuNPs shows an excellent cytotoxic result against HeLa cancer cell lines at different concentrations.

  3. Acaricidal activity of synthesized titanium dioxide nanoparticles using Calotropis gigantea against Rhipicephalus microplus and Haemaphysalis bispinosa

    Institute of Scientific and Technical Information of China (English)

    Sampath; Marimuthu; Abdul; Abdul; Rahuman; Chidambaram; Jayaseelan; Arivarasan; Vishnu; Kirthi; Thirunavukkarasu; Santhoshkumar; Kanayairam; Velayutham; Asokan; Bagavan; Chinnaperumal; Kamaraj; Gandhi; Elango; Moorthy; Iyappan; Chinnadurai; Siva; Loganathan; Karthik; Kokati; Venkata; Bhaskara; Rao

    2013-01-01

    Objective:To assess the acaricidal activity of titanium dioxide nanoparticles(TiO2 NPs)synthesized from flower aqueous extract of Calotropis gigantea(C.gigantea)against the larvae of Rhipicephalus(Boophilus)microplus[R.(B.)microplus]and the adult of Haemaphrysalis bispinosa(H.bispinosa).Methods:The lyophilized C.gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH2)(10 mM)and magnetically stirred for 6 h.Synthesized TiO2 NPs were characterized by X-ray diffraction(XRD).Fourier transform infrared spectroscopy(FTIR),Scanning electron microscopy(SEM),and Energy dispersive X-ray spectroscopy(EDX).The synthesised TiO2 NPs were tested against the larvae of R(B.)microplus and adult of H.bispinosa were exposed to filter paper impregnated method.Results:XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm.The functional groups for synthesized TiO2NPs were 1405.19,and 1053.45 cm-1for-NH2 bending,primary amines and amides and 1053.84and 1078.45 cm-1for C-O.SEM micrographs of the synthesized TiO2 NPs showed the aggregated and spherical in shape.The maximum efficacy was observed in the aqueous flower extract of C.gigantea and synthesized TiO2 NPs against R.(B.)microplus(LC50=24.63 and 5.43 mg/L and r2=0.960 and 0.988)and against H.bispinosa(LC50=35.22 and 9.15 mg/L and r2=0.969 and 0.969).respectively.Conclusions:The synthesized TiO2 NPs were highly stable and had significant acaricidal activity against the larvae of R.(B.)microplus and adult of H.bispinosa.This study provides the first report of synthesized TiO2 NPs and possessed excellent anti-parasitic activity.

  4. Effect of aging on copper nanoparticles synthesized by pulsed laser ablation in water: structural and optical characterizations

    Indian Academy of Sciences (India)

    R K Swarnkar; S C Singh; R Gopal

    2011-12-01

    Effect of aging on copper nanoparticles synthesized by pulsed laser ablation of copper plate in water was studied. By characterization studies of the aged nanoparticles, it is found that copper nanoparticles converted into Cu@Cu2O nanostructure. The synthesized nanomaterial is characterized with UV-Visible absorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman and photoluminescence (PL) spectroscopic techniques. TEM image shows that the aged nanoparticles get assembled into cactus like structure and are spherical in shape with average diameter 7 nm and dispersion 2 nm. XRD and FTIR spectrum confirm the formation of Cu@Cu2O in the aged sample. Raman spectrum also confirms the presence of Cu2O nanoparticles. PL spectrum of the aged nanoparticles shows a direct allowed transition with bandgap energy of 2.24 eV. The mechanism for synthesis of core-shell nanoparticles and formation of self-assembly of nanoparticles is also discussed.

  5. Spectral Studies of UV and Solar Photocatalytic Degradation of AZO Dye and Textile Dye Effluents Using Green Synthesized Silver Nanoparticles.

    Science.gov (United States)

    Mariselvam, R; Ranjitsingh, A J A; Mosae Selvakumar, P; Alarfaj, Abdullah A; Munusamy, Murugan A

    2016-01-01

    The photocatalytic degradation of the chemical dye AZO and dye effluents in different time duration has been investigated using biologically synthesized silver nanoparticles. Dye industry effluents and AZO dye undergo degradation to form harmless intermediate and colourless products following irradiation by UV and solar light in the presence of green synthesized silver nanoparticles. The degree of degradation was tested under the experimental conditions such as P(H), temperature, and absorbance of the dye in UV and solar light was measured. The degradation was higher in the UV light source than in the solar light source. Green synthesized silver nanoparticles in the UV light source were found to expedite the dye degradation process. PMID:27382364

  6. Electrokinetic properties of PMAA functionalized NiFe2O4 nanoparticles synthesized by thermal plasma route

    Science.gov (United States)

    Bhosale, Shivaji V.; Mhaske, Pravin; Kanhe, N.; Navale, A. B.; Bhoraskar, S. V.; Mathe, V. L.; Bhatt, S. K.

    2014-04-01

    The magnetic nickel ferrite (NiFe2O4) nanoparticles with an average size of 30nm were synthesised by Transferred arc DC Thermal Plasma route. The synthesized nickel ferrite nanoparticles were characterized by TEM and FTIR techniques. The synthesized nickel ferrite nanoparticles were further functionalized with PMAA (polymethacrylic acid) by self emulsion polymerization method and subsequently were characterized by FTIR and Zeta Analyzer. The variation of zeta potential with pH was systematically studied for both PMAA functionalized (PNFO) and uncoated nickel ferrite nanoparticles (NFO). The IEP (isoelectric points) for PNFO and NFO was determined from the graph of zeta potential vs pH. It was observed that the IEP for NFO was at 7.20 and for PNFO it was 2.52. The decrease in IEP of PNFO was attributed to the COOH functional group of PMAA.

  7. Plant extract synthesized PLA nanoparticles for controlled and sustained release of quercetin: a green approach.

    Directory of Open Access Journals (Sweden)

    Avnesh Kumari

    Full Text Available BACKGROUND: Green synthesis of metallic nanoparticles (NPs has been extensively carried out by using plant extracts (PEs which have property of stabilizers/emulsifiers. To our knowledge, there is no comprehensive study on applying a green approach using PEs for fabrication of biodegradable PLA NPs. Conventional methods rely on molecules like polyvinyl alcohol, polyethylene glycol, D-alpha-tocopheryl poly(ethylene glycol 1000 succinate as stabilizers/emulsifiers for the synthesis of such biodegradable NPs which are known to be toxic. So, there is urgent need to look for stabilizers which are biogenic and non-toxic. The present study investigated use of PEs as stabilizers/emulsifiers for the fabrication of stable PLA NPs. Synthesized PLA NPs through this green process were explored for controlled release of the well known antioxidant molecule quercetin. METHODOLOGY/PRINCIPAL FINDINGS: Stable PLA NPs were synthesized using leaf extracts of medicinally important plants like Syzygium cumini (1, Bauhinia variegata (2, Cedrus deodara (3, Lonicera japonica (4 and Eleaocarpus sphaericus (5. Small and uniformly distributed NPs in the size range 70±30 nm to 143±36 nm were formed with these PEs. To explore such NPs for drugs/ small molecules delivery, we have successfully encapsulated quercetin a lipophilic molecule on a most uniformly distributed PLA-4 NPs synthesized using Lonicera japonica leaf extract. Quercetin loaded PLA-4 NPs were observed for slow and sustained release of quercetin molecule. CONCLUSIONS: This green approach based on PEs mediated synthesis of stable PLA NPs pave the way for encapsulating drug/small molecules, nutraceuticals and other bioactive ingredients for safer cellular uptake, biodistribution and targeted delivery. Hence, such PEs synthesized PLA NPs would be useful to enhance the therapeutic efficacy of encapsulated small molecules/drugs. Furthermore, different types of plants can be explored for the synthesis of PLA as well

  8. Nanostructural Features of Silver Nanoparticles Powder Synthesized through Concurrent Formation of the Nanosized Particles of Both Starch and Silver

    OpenAIRE

    A. Hebeish; El-Rafie, M. H.; El-Sheikh, M. A.; Mehrez E. El-Naggar

    2013-01-01

    Green innovative strategy was developed to accomplish silver nanoparticles formation of starch-silver nanoparticles (St-AgNPs) in the powder form. Thus, St-AgNPs were synthesized through concurrent formation of the nanosized particles of both starch and silver. The alkali dissolved starch acts as reducing agent for silver ions and as stabilizing agent for the formed AgNPs. The chemical reduction process occurred in water bath under high-speed homogenizer. After completion of the reaction, the...

  9. Microalgae associated Brevundimonas sp. MSK 4 as the nano particle synthesizing unit to produce antimicrobial silver nanoparticles

    Science.gov (United States)

    Rajamanickam, Karthic; Sudha, S. S.; Francis, Mebin; Sowmya, T.; Rengaramanujam, J.; Sivalingam, Periyasamy; Prabakar, Kandasamy

    2013-09-01

    The biosynthesis of silver nanoparticles and its antimicrobial property was studied using bacteria isolated from Spirulina products. Isolated bacteria were identified as Bacillus sp. MSK 1 (JX495945), Staphylococcus sp. MSK 2 (JX495946), Bacillus sp. MSK 3 (JX495947) and Brevundimonas sp. MSK 4 (JX495948). Silver nanoparticles (AgNPs) were synthesized using bacterial culture filtrate with AgNO3. The initial syntheses of Ag nanoparticles were characterized by UV-vis spectrophotometer (by measuring the color change to intense brown). Fourier Transform Infrared Spectroscopy (FTIR) study showed evidence that proteins are possible reducing agents and Energy-dispersive X-ray (EDX) study showing the metal silver as major signal. The structure of AgNPs was determined by Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Synthesized Ag nanoparticles with an average size of 40-65 nm have antimicrobial property against human pathogens like Proteus vulgaris, Salmonella typhi, Vibrio cholera, Streptococcus sp., Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. Among the isolates Brevundimonas sp. MSK 4 alone showed good activity in both synthesis of AgNPs and antimicrobial activity. This work demonstrates the possible use of biological synthesized silver nanoparticles to combat the drug resistant problem.

  10. Effect of zinc oxide nanoparticles synthesized by a precipitation method on mechanical and morphological properties of the CR foam

    Indian Academy of Sciences (India)

    Rudeerat Suntako

    2015-08-01

    ZnO nanoparticles were synthesized by a precipitation method in aqueous media from zinc nitrate hexahydrate and sodium hydroxide. The synthesized ZnO nanoparticles exhibited a crystalline structure with hexagonal structure of the wurtzite. The morphology of the synthesized ZnO nanoparticles presented a spherical shape with the average primary size of 54.53 nm and the specific surface area of 20.28 m2 g−1. The effect of the synthesized ZnO nanoparticles by the precipitation method as a crosslinking agent for chloroprene rubber foam (CR foam) on cure characteristics, mechanical properties and morphologies was investigated. The aim of this study is to vary the synthesized ZnO nanoparticles’ level in the range of 0.5–5 parts per hundred parts of rubber (phr) compared with the conventional ZnO at 5 phr. The rheological characterization showed that the maximum torque (H), the minimum torque (L), the differential torque (H–L) and Mooney viscosity increased with the increase in synthesized ZnO nanoparticles’ content, whereas the optimum cure time (90) and scorch time (5) decreased. On the other hand, the mechanical properties such as hardness, tensile strength and specific gravity were improved. For CR foam, the results compared to the amount of conventional ZnO, only 60 wt% (3 phr) nano-ZnO was enough to obtain similar cure characteristics and mechanical properties. The synthesized ZnO nanoparticles showed the mechanical properties higher than conventional ZnO because of small particle size and large specific surface area which led to the increase in the degree of crosslinking.

  11. In-vitro anticancer activity of green synthesized silver nanoparticles on MCF-7 human breast cancer cells.

    Science.gov (United States)

    Jang, Suk Ju; Yang, In Jun; Tettey, Clement O; Kim, Ki Mo; Shin, Heung Mook

    2016-11-01

    In recent years, green synthesis of metallic nanoparticles is a growing area of research because of their potential applications in nanomedicine. In the present study we synthesized silver nanoparticles (silver NPs) from AgNO3 using aqueous extract of Lonicera hypoglauca flower as reducing and capping agents. The synthesized silver NPs were characterized using UV-Vis spectroscopy, FTIR, SEM-ED, TEM and SAED. Silver NPs were found to be significantly toxic to MCF-7 cells via the induction of apoptosis whereas sparing normal immune system (RAW 264.7) cells. PMID:27524038

  12. Biogenic ZnO nanoparticles synthesized using L. aculeata leaf extract and their antifungal activity against plant fungal pathogens

    Indian Academy of Sciences (India)

    S Narendhran; Rajeshwari Sivaraj

    2016-02-01

    In this study, Zinc oxide (ZnO) nanoparticles were synthesized using aqueous extract of Lantana aculeata Linn. leaf and assessed their effects on antifungal activity against the plant fungal pathogens. Synthesized nanoparticles were confirmed by ultraviolet–visible spectroscopy, Fourier transform infrared spectrometer, energy-dispersive X-ray spectrometer, X-ray diffractometer, Field-emission scanning electron microscopy, high-resolution transmission electron microscopy. The antifungal activity of ZnO nanoparticles were determined using the well diffusion method. All the characterization analyses revealed that nanoparticles were highly stable and crystalline in nature. L. aculeata-mediated ZnO nanoparticles were spherical in shape with an average particle size of 12 ± 3 nm. Antifungal studies concluded that the maximum zone of inhibition was observed in Aspergillus flavus (21 ± 1.0 mm) and Fusarium oxysporum (19 ± 1.0 mm) at 100 g ml-1 concentration. These results clearly indicated the benefits of using ZnO nanoparticles synthesized using biological methods and shown to have antifungal activities and also that it can be effectively used as antifungal agent in environmental aspect of agricultural development.

  13. Histopathological studies and oxidative stress of synthesized silver nanoparticles in Mozambique tilapia (Oreochromis mossambicus)

    Institute of Scientific and Technical Information of China (English)

    Rajakumar Govindasamy; Abdul Abdul Rahuman

    2012-01-01

    To evaluate the potential environmental effects of engineered nano metals,it is important to determine the adverse effects of various nanomaterials on aquatic species.Adult tilapia (Oreochromis mossambicus) were maintained in 10 L glass aquaria,and exposed to a graded series of synthesized silver nanoparticles (Ag-NPs) at 25,50 and 75 mg/L for eight days.The LC50 value was 12.6 mg/L.Reduced activities of antioxidant enzymes and the contents of antioxidants were lowered in the gills and liver of fishes treated with Ag-NPs,which resulted in heavy accumulation of free radicals.Histopathological results imply that the balance between the oxidative and antioxidant system in the fish was broken down during Ag-NPs exposure.The principal coneern related with the release of nanomaterials and their smaller particle may change the materials transport and potential toxicity to aquatic organisms compared to larger particles.

  14. Green synthesized cerium oxide nanoparticle: A prospective drug against oxidative harm.

    Science.gov (United States)

    Dutta, Debanjan; Mukherjee, Riya; Patra, Mousumi; Banik, Milon; Dasgupta, Rakhi; Mukherjee, Manabendra; Basu, Tarakdas

    2016-11-01

    Cerium oxide nanoparticle (CeONP) of size 2-3nm was synthesized by a new, simple and green method at ambient temperature, using cerium nitrate as prime precursor and Aloe vera leaf extract as stabilizing agent. Of the two oxidation states (+3) and (+4) of cerium, it was dominantly present in (+3) state in CeONP and cyclic conversion of Ce(III)O→Ce(IV)O→Ce(III)O by reaction with H2O2 implied uninterrupted antioxidant property of CeONP. Moreover, the higher oxygen defect in the crystal lattice produced particles with higher antioxidant activity. CeONP was found to neutralize the deleterious effects of H2O2 viz., cell death, generation of intracellular reactive oxygen species and loss of connectivity in mouse neural cells. Therefore, CeONP might have potential use in future as an anti-oxidant drug. PMID:27478962

  15. Isolation and identification of gold nanoparticles synthesizing fungi from Indian Kolar Gold Field mine soil.

    Science.gov (United States)

    Lakshmi, V Jhansi; Kannan, K P

    2016-07-01

    An indigenous fungal strain was isolated from Indian Kolar Gold Field mine soil. The isolate was heterothallic, branched septate, deeply floccose, fast-growing, dull green with white background conidial columnar mycelium from Aspergillus section Fumigati. Diverse metabolic patterns of the isolate exhibit high metal, thermal resistance which grews well from 28 ± 1 degrees C to 37 degrees C and pH concentration was significant on the growth of isolate. Phylogenetic analysis of 16srRNA β-Tubulin gene sequence established relationship among isolate and other taxa. Molecular identification and morphological features of fungal isolate were consistent with those of Neosartorya udagawae. Heterothallic N. udagawae FJ830683 strain was closely related to homothallic N. aureola EF661890. Fungal isolate extract synthesized narrow sized stable Gold nanoparticles (AuNPs). PMID:27498502

  16. Photodegradation of m-cresol with synthesized Mn doped ZnO nanoparticles under visible light

    International Nuclear Information System (INIS)

    Full text: Various percent of Mn-doped ZnO nanoparticles were synthesized by co-precipitation method. They have been tested in photodegradation of m-cresol under visible light irradiation. Optimum photodegradation was observed with 1.0 wt % Mn-doped ZnO. Undoped and 1.0 wt % Mn doped Photo catalysts were characterized by means of X-ray diffraction (XRD), atomic force microscopic (AFM), and transmission electron microscopy (TEM). The optical absorption was examined using UV-vis spectrophotometer. The results showed that 1.0 wt % Mn-doped ZnO comparing with undoped ZnO had higher surface area, and finer particles size. Also optical absorption shifted to visible light in 1.0 wt % Mn doped ZnO. Therefore, Mn doping in ZnO may enhance the photo catalyst activity of ZnO under visible light. (author)

  17. Magnetic nanoparticles for biophysical applications synthesized by high-power physical dispersion

    Science.gov (United States)

    Safronov, A. P.; Beketov, I. V.; Tyukova, I. S.; Medvedev, A. I.; Samatov, O. M.; Murzakaev, A. M.

    2015-06-01

    The low cost and high output methods of high-power physical dispersion: the electrical explosion of wire and the laser target evaporation were elaborated for the production of iron oxide magnetic nanoparticles (MNPs) with controlled dispersion parameters and highly reproducible functional properties. The synthesized MNPs were spherical in shape with mean diameter 10 nm and lognormal particle size distribution. The phase composition, shape, particle size and functional properties of MNPs were cross-examined by a variety of contemporary experimental techniques. The phase structure of MNPs corresponds to the inverse spinel of magnetite. Meanwhile, due to the non-equilibrium conditions of the dispersion chemical composition of MNPs is close to maghemite-γ-Fe2O3. Their magnetic properties are reproducible and very close to the single domain superparamagnetic behavior. The stability of the suspensions of these MNPs and their applicability in the biophysical purposes such as magneto-induced heating have been demonstrated.

  18. Dielectric properties of CdS nanoparticles synthesized by soft chemical route

    Indian Academy of Sciences (India)

    R Tripathi; A Kumar; T P Sinha

    2009-06-01

    CdS nanoparticles have been synthesized by a chemical reaction route using thiophenol as a capping agent. The frequency-dependent dielectric dispersion of cadmium sulphide (CdS) is investigated in the temperature range of 303–413 K and in a frequency range of 50 Hz–1 MHz by impedance spectroscopy. An analysis of the complex permittivity (′ and ″) and loss tangent (tan ) with frequency is performed by assuming a distribution of relaxation times. The scaling behaviour of dielectric loss spectra suggests that the relaxation describes the same mechanism at various temperatures. The frequency-dependent electrical data are analysed in the framework of conductivity and modulus formalisms. The frequency-dependent conductivity spectra obey the power law.

  19. Biological approach to synthesize TiO2 nanoparticles using Aeromonas hydrophila and its antibacterial activity.

    Science.gov (United States)

    Jayaseelan, Chidambaram; Rahuman, Abdul Abdul; Roopan, Selvaraj Mohana; Kirthi, Arivarasan Vishnu; Venkatesan, Jayachandran; Kim, Se-Kwon; Iyappan, Moorthy; Siva, Chinnadurai

    2013-04-15

    Nanosized materials have been an important subject in basic and applied sciences. A novel, low-cost, green and reproducible bacteria, Aeromonas hydrophila mediated biosynthesis of titanium dioxide nanoparticles (TiO2 NPs) was reported. The resulting nanoparticles were characterized by FTIR, XRD, AFM and FESEM with EDX. FTIR showed characteristic bands (1643 and 3430 cm(-1)) finds the role of carboxyl group OH stretching amine NH stretch in the formation of TiO2 NPs. The XRD spectrum confirmed that the synthesized TiO2 NPs were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.47°, 31.77°, 36.11°, 41.25°, 54.39°, 56.64° and 69.54° were identified as 110, 100, 101, 111, 211, 220 and 301 reflections, respectively. The crystallite sizes were calculated using Scherrer's formula applied to the major intense peaks and found to be the size of 40.50 nm. The morphological characterization was analyzed by FESEM and the analysis showed the NPs smooth shaped, spherical and uneven. GC-MS analysis showed the main compounds found in A. hydrophila were uric acid (2.95%), glycyl-L-glutamic acid (6.90%), glycyl-L-proline (74.41%) and L-Leucyl-D-leucine (15.74%). The potential glycyl-L-proline could have played an important role as a capping agent. A possible mechanism for the biosynthesis of TiO2 NPs has been proposed. The antibacterial activity of the synthesized TiO2 NPs was assessed by well diffusion method toward A. hydrophila, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis and showed effective inhibitory activity against S. aureus (33 mm) and S. pyogenes (31 mm). PMID:23416912

  20. Biological approach to synthesize TiO2 nanoparticles using Aeromonas hydrophila and its antibacterial activity

    Science.gov (United States)

    Jayaseelan, Chidambaram; Rahuman, Abdul Abdul; Roopan, Selvaraj Mohana; Kirthi, Arivarasan Vishnu; Venkatesan, Jayachandran; Kim, Se-Kwon; Iyappan, Moorthy; Siva, Chinnadurai

    2013-04-01

    Nanosized materials have been an important subject in basic and applied sciences. A novel, low-cost, green and reproducible bacteria, Aeromonas hydrophila mediated biosynthesis of titanium dioxide nanoparticles (TiO2 NPs) was reported. The resulting nanoparticles were characterized by FTIR, XRD, AFM and FESEM with EDX. FTIR showed characteristic bands (1643 and 3430 cm-1) finds the role of carboxyl group Osbnd H stretching amine Nsbnd H stretch in the formation of TiO2 NPs. The XRD spectrum confirmed that the synthesized TiO2 NPs were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.47°, 31.77°, 36.11°, 41.25°, 54.39°, 56.64° and 69.54° were identified as 110, 100, 101, 111, 211, 220 and 301 reflections, respectively. The crystallite sizes were calculated using Scherrer's formula applied to the major intense peaks and found to be the size of 40.50 nm. The morphological characterization was analyzed by FESEM and the analysis showed the NPs smooth shaped, spherical and uneven. GC-MS analysis showed the main compounds found in A. hydrophila were uric acid (2.95%), glycyl-L-glutamic acid (6.90%), glycyl-L-proline (74.41%) and l-Leucyl-d-leucine (15.74%). The potential glycyl-L-proline could have played an important role as a capping agent. A possible mechanism for the biosynthesis of TiO2 NPs has been proposed. The antibacterial activity of the synthesized TiO2 NPs was assessed by well diffusion method toward A. hydrophila, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis and showed effective inhibitory activity against S. aureus (33 mm) and S. pyogenes (31 mm).

  1. Phytoextracts-Synthesized Silver Nanoparticles Inhibit Bacterial Fish Pathogen Aeromonas hydrophila.

    Science.gov (United States)

    Mahanty, Arabinda; Mishra, Snehasish; Bosu, Ranadhir; Maurya, Uk; Netam, Surya Prakash; Sarkar, Biplab

    2013-12-01

    Fish disease is a major stumbling block towards sustainable growth of the fisheries sector. Aeromonas hydrophila, which is a major infectious aquatic pathogen is reportedly the causative agent of ulcers, fin-rot, tail-rot, hemorrhagic septicemia in fish, and has reportedly developed resistance against many of the available antibiotics. In this context, the inhibitory function of silver nanoparticles (AgNPs) against A. hydrophila was studied to evaluate its possible application in aquaculture as alternative to antibiotics. AgNPs were synthesized using the leaf extracts of subtropical plants Mangifera indica (Mango), Eucalyptus terticornis (Eucalyptus), Carica papaya (Papaya) and Musa paradisiaca (Banana). The absorbance maxima, size range and shape of the AgNPs as characterized by the UV-Vis spectroscopy, high resolution transmission electron microscopy (HR-TEM), and energy dispersive X-ray spectroscopy (EDX) were, Mangifera-442, 50-65 nm, ovular; Eucalyptus-465, 60-150 nm, oval; Carica-442, 25-40 nm, round, irregular; and Musa-454, 10-50 nm, round, irregular, respectively. Well-diffusion of these AgNPs for their antimicrobial characteristics exhibited that, the papaya leaf extract synthesized AgNPs had maximum antimicrobial activity at 153.6 μg/ml concentrations, and that from the eucalyptus leaves was least effective. As observed, the potency of the nanoparticles enhanced with the decrease in particle size, from 60-150 nm in eucalyptus to 25-40 nm in papaya. Due to its purely natural sourcing, phytosynthesized AgNPs can be applied as alternative to antibiotics and other biocides as a cost-effective and eco-friendly therapeutic agent against A. hydrophila stimulated diseases in aquatic animals. PMID:24426148

  2. Synthesis and Raman analysis of SnS nanoparticles synthesized by PVP assisted polyol method

    International Nuclear Information System (INIS)

    SnS film was prepared by a simple drop casting method after synthesizing SnS nanoparticles by using PVP assisted polyol method. Confocal Raman study was carried out for the as deposited and annealed (150, 300 and 400 °C) films at two different excitation wavelengths 514 and 785 nm. At the excitation wavelength of 514 nm, the Raman modes showed for a mixed phase of SnS and SnS2 up to 150 °C and then only a pure SnS phase was observed up to 400 °C due to the dissociation of SnS2 in to SnS by releasing S. The increase in intensity of Raman (Ag and B3g) as well as IR (B3u) active modes of SnS are observed with increasing annealing temperature at excitation wavelength 785 nm due to the increased crystallinity and inactiveness of SnS2 modes. X-ray diffraction confirming the formation of a single phase of SnS while the greater homogeneity in both size and shape of SnS nanoparticles were confirmed through surface morphology from SEM

  3. Optical properties of Germanium nanoparticles synthesized by pulsed laser ablation in acetone

    Directory of Open Access Journals (Sweden)

    Saikiran eVadavalli

    2014-10-01

    Full Text Available Germanium (Ge nanoparticles (NPs are synthesized by means of pulsed laser ablation of bulk germanium target immersed in acetone with ns laser pulses at different pulse energies. The fabricated NPs are characterized by employing different techniques such as UV-visible absorption spectroscopy, photoluminescence, micro-Raman spectroscopy, transmission electron microscopy (TEM and field emission scanning electron microscopy (FESEM. The mean size of the Ge NPs is found to vary from few nm to 40 nm with the increase in laser pulse energy. Shift in the position of the absorption spectra is observed and also the photoluminescence peak shift is observed due to quantum confinement effects. High resolution TEM combined with micro-Raman spectroscopy confirms the crystalline nature of the generated germanium nanoparticles. The formation of various sizes of germanium NPs at different laser pulse energies is evident from the asymmetry in the Raman spectra and the shift in its peak position towards the lower wavenumber side. The FESEM micrographs confirm the formation of germanium micro/nanostructures at the laser ablated position of the bulk germanium. In particular, the measured NP sizes from the micro-Raman phonon quantum confinement model are found in good agreement with TEM measurements of Ge NPs.

  4. Cadmium Sulfide Nanoparticles Synthesized by Microwave Heating for Hybrid Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Claudia Martínez-Alonso

    2014-01-01

    Full Text Available Cadmium sulfide nanoparticles (CdS-n are excellent electron acceptor for hybrid solar cell applications. However, the particle size and properties of the CdS-n products depend largely on the synthesis methodologies. In this work, CdS-n were synthetized by microwave heating using thioacetamide (TA or thiourea (TU as sulfur sources. The obtained CdS-n(TA showed a random distribution of hexagonal particles and contained TA residues. The latter could originate the charge carrier recombination process and cause a low photovoltage (Voc, 0.3 V in the hybrid solar cells formed by the inorganic particles and poly(3-hexylthiophene (P3HT. Under similar synthesis conditions, in contrast, CdS-n synthesized with TU consisted of spherical particles with similar size and contained carbonyl groups at their surface. CdS-n(TU could be well dispersed in the nonpolar P3HT solution, leading to a Voc of about 0.6–0.8 V in the resulting CdS-n(TU : P3HT solar cells. The results of this work suggest that the reactant sources in microwave methods can affect the physicochemical properties of the obtained inorganic semiconductor nanoparticles, which finally influenced the photovoltaic performance of related hybrid solar cells.

  5. Structural and optical properties of chromium doped zinc oxide nanoparticles synthesized by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, Syed Mohd. Adnan, E-mail: adiaks2004@yahoo.co.in [Department of Fundamental and Applied Sciences, Universiti Teknologi Petronas, Bandar Seri Iskandar, Perak (Malaysia); Irshad, Kashif, E-mail: alig.kashif@gmail.com [Department of Mechanical Engineering, Universiti Teknologi Petronas, Bandar Seri Iskandar, Perak (Malaysia); Soleimani, Hassan, E-mail: hassan.soleimani@petronas.com.my, E-mail: noorhana-yahya@petronas.com.my; Yahya, Noorhana, E-mail: hassan.soleimani@petronas.com.my, E-mail: noorhana-yahya@petronas.com.my

    2014-10-24

    Nanosized Cr-doped ZnO nano particles were synthesized by facile sol-gel auto combustion method. The structural and optical properties of Cr-doped ZnO nanoparticles have been investigated by XRD and UV-Vis spectroscopy at room temperature for 0% to 8% concentration. X-ray diffraction analysis reveals that the Cr-doped ZnO crystallizes in a single phase polycrystalline nature with wurtzite lattice. With every % of doping, the peaks are shifting scarcely and doping of Cr is possible up to 7%. After that, the last peak vanishes, that signifies its structure is transmuted from 8% doping. The average crystallite size decreases with increase in Cr concentration (i.e. 28.9 nm for 0% to 25.8 nm for 8%). The UV-Vis spectra of the nanoparticles betoken an incrementation in the band gap energy from 3.401, 3.415, 3.431, 3.437,3.453, 3.514,3.521, 3.530 and 3.538 eV respectively, for 0,1, 2, 3, 4, 5, 6, 7 and 8 % doping concentration.

  6. Size dependence of the bandgap of plasma synthesized silicon nanoparticles through direct introduction of sulfur hexafluoride

    Energy Technology Data Exchange (ETDEWEB)

    Theingi, S.; Guan, T. Y.; Klafehn, G.; Taylor, P. C.; Lusk, M. T.; Collins, R. T., E-mail: rtcollin@mines.edu [Department of Physics, Colorado School of Mines, Golden, Colorado 80401 (United States); Renewable Energy Materials Research Science and Engineering Center, Colorado School of Mines, Golden, Colorado 80401 (United States); Kendrick, C. [Department of Physics, Colorado School of Mines, Golden, Colorado 80401 (United States); Renewable Energy Materials Research Science and Engineering Center, Colorado School of Mines, Golden, Colorado 80401 (United States); Electrical and Computer Engineering, Michigan Technological University, Houghton, Michigan 49931 (United States); Gorman, B. P. [Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States); Stradins, P. [Renewable Energy Materials Research Science and Engineering Center, Colorado School of Mines, Golden, Colorado 80401 (United States); National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

    2015-10-19

    Developing silicon nanoparticle (SiNP) synthesis techniques that allow for straightforward control of nanoparticle size and associated optical properties is critical to potential applications of these materials. In addition, it is, in general, hard to probe the absorption threshold in these materials due to silicon's low absorption coefficient. In this study, size is controlled through direct introduction of sulfur hexafluoride (SF{sub 6}) into the dilute silane precursor of plasma synthesized SiNPs. Size reduction by nearly a factor of two with high crystallinity independent of size is demonstrated. The optical absorption spectra of the SiNPs in the vicinity of the bandgap are measured using photothermal deflection spectroscopy. Bandgap as a function of size is extracted taking into account the polydispersity of the samples. A systematic blue shift in absorption edge due to quantum confinement in the SiNPs is observed with increasing flow of SF{sub 6}. Photoluminescence (PL) spectra show a similar blue shift with size. However, a ∼300 meV difference in energy between emission and absorption for all sizes suggests that PL emission involves a defect related process. This shows that, while PL may allow size-induced shifts in the bandgap of SiNPs to be monitored, it cannot be relied on to give an accurate value for the bandgap as a function of size.

  7. Physicochemical characterization of silver nanoparticles synthesize using Aloe Vera (Aloe barbadensis)

    Science.gov (United States)

    Kuponiyi, Abiola; Kassama, Lamin; Kukhtareva, Tatiana

    2014-08-01

    Production of silver nanoparticles (AgNPs) using different biological methods is gaining recognition due to their multiple applications. Although, several physical and chemical methods have been used for the synthesis and stabilizing of AgNPs, yet, a green chemistry method is preferable because it is cost effective and environmentally friendly. The synthesis was done using Aloe Vera (AV) extract because it has chemical compounds such as "Antrokinon" that are known for its antibacterial, antivirus and anticancer properties. We hypothesize that AV extract can produce a stable nanoparticles within the 100 nm range and be biologically active. The biological compounds were extracted from AV skin with water and ethanol which was used as the reduction agent for the synthesis of nanoparticles. The biological extract and AgNO3 were blended and heated to synthesize AgNPs. The reaction process was monitored using UV-Visible spectroscopy. Fourier Transfer Infrared spectroscopy (FTIR) was used for the characterization of biological compounds and their substituent groups before and after the reaction process. Dynamic Light scattering (DLS) method was used to characterize particle size of AgNPs and their biomolecular stability. Results showed that biological compounds such as aliphatic amines, alkenes (=C-H), alkanes (C-H), alcohol (O-H) and unsaturated esters(C-O), which has an average particle size of 109 and 215.8 nm and polydispersity index of 0.451 and 0.375 for ethanol and water extract, respectively. According to TEM measurements the size of AgNPs are in the range 5-20 nm The results suggested that ethanol derived AgNPs contained higher yield of organic compounds, thus has better solubility power than water. Ag NPs can be used to control salmonella in poultry industry.

  8. Evaluation of antibacterial activity of zinc oxide nanoparticles synthesized using phycobilins of Anabaena variabilisNTSS17

    Institute of Scientific and Technical Information of China (English)

    Thangaraj Ramasamy; Santhoshkumar Subramaniyam; Dhanasekaran Dharumadurai; Kala Karuppannan; Alharbi Naiyf Sultan; Arunachalam Chinnathambi; Ali Alharbi Sulaiman; Thajuddin Nooruddin

    2015-01-01

    Objective:To evaluate the antibacterial activity of zinc oxide nanoparticles synthesized using phycobilins ofAnabaenavariabilis NTSS17. Methods:The cyanobacterial isolate was collected from paddy field and morphologically identified asAnabaenavariabilis NTSS17, that produces a pigmenti.e. phycobiliproteins. The biosynthesized zinc nanoparticles were characterized by different spectroscopic and analytical techniques such as UV-visible spectrophotometer, Fourier transform infrared spectroscopy and X-ray diffraction which confirmed the formation of zinc nanoparticles. Results: Antibacterial activity of zinc oxide nanoparticles was examined againstEscherichia coli,Rhodococcus rhodochrous andPseudomonas aeruginosa. The maximum zone of inhibition occurred at 5 mg/1 000 mL concentration of zinc oxide nanoparticles. Conclusions:Due to potent antimicrobial and intrinsic properties of zinc oxide, it can be actively used for biomedical applications.

  9. Optical and ammonia-sensing properties of SnO2 nanoparticles synthesized using a 900 W microwave

    Science.gov (United States)

    Klinbumrung, Arrak; Thongtem, Titipun; Phuruangrat, Anukorn; Thongtem, Somchai

    2016-08-01

    SnO2 nanoparticles were successfully synthesized using a 900 W microwave for 10, 20, and 30 min. Tetragonal SnO2 nanoparticles composed of Sn and O were detected by X-ray diffraction (XRD), selected area electron diffraction (SEAD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and transmission electron microscopy (TEM). The SnO2 nanoparticles processed for 30 min were the best crystals. The 3.5 eV energy gap and 395 nm emission wavelength were determined by UV-visible absorption and photoluminescence (PL) spectroscopy. The gas-sensing performance of SnO2 nanoparticles during exposure to an NH3-air mixture was studied at different working temperatures and NH3 concentrations. At 1055 ppm NH3 and 350 °C, the SnO2 nanoparticles showed a sensitivity of 9.2 with the response and recovery times of 9 and 37 s, respectively.

  10. Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO.sub.2 reforming of methane

    KAUST Repository

    Biausque, Gregory

    2015-04-28

    Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO.sub.2 reforming of methane

  11. Evaluation of tetraethoxysilane (TEOS) sol-gel coatings, modified with green synthesized zinc oxide nanoparticles for combating microfouling.

    Science.gov (United States)

    Krupa, A Nithya Deva; Vimala, R

    2016-04-01

    Green synthesis of zinc oxide nanoparticles (ZnO-NPs) is gaining importance as an eco-friendly alternative to conventional methods due to its enormous applications. The present work reports the synthesis of ZnO-NPs using the endosperm of Cocos nucifera (coconut water) and the bio-molecules responsible for nanoparticle formation have been identified. The synthesized nanoparticles were characterized using UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Zeta potential measurement. The results obtained reveal that the synthesized nanoparticles are moderately stable with the size ranging from 20 to 80 nm. The bactericidal effect of the nanoparticles was proved by well diffusion assay and determination of minimum inhibitory concentration (MIC) against marine biofilm forming bacteria. Further the green synthesized ZnO-NPs were doped with TEOS sol-gels (TESGs) in order to assess their antimicrofouling capability. Different volumes of liquid sol-gels were coated on to 96-well microtitre plate and cured under various conditions. The optimum curing conditions were found to be temperature 60 °C, time 72 h and volume 200 μl. Antiadhesion test of the undoped (SG) and ZnO-NP doped TEOS sol-gel (ZNSG) coatings were evaluated using marine biofilm forming bacteria. ZNSG coatings exhibited highest biofilm inhibition (89.2%) represented by lowest OD value against Pseudomonasotitidis strain NV1.

  12. Evaluation of tetraethoxysilane (TEOS) sol-gel coatings, modified with green synthesized zinc oxide nanoparticles for combating microfouling.

    Science.gov (United States)

    Krupa, A Nithya Deva; Vimala, R

    2016-04-01

    Green synthesis of zinc oxide nanoparticles (ZnO-NPs) is gaining importance as an eco-friendly alternative to conventional methods due to its enormous applications. The present work reports the synthesis of ZnO-NPs using the endosperm of Cocos nucifera (coconut water) and the bio-molecules responsible for nanoparticle formation have been identified. The synthesized nanoparticles were characterized using UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Zeta potential measurement. The results obtained reveal that the synthesized nanoparticles are moderately stable with the size ranging from 20 to 80 nm. The bactericidal effect of the nanoparticles was proved by well diffusion assay and determination of minimum inhibitory concentration (MIC) against marine biofilm forming bacteria. Further the green synthesized ZnO-NPs were doped with TEOS sol-gels (TESGs) in order to assess their antimicrofouling capability. Different volumes of liquid sol-gels were coated on to 96-well microtitre plate and cured under various conditions. The optimum curing conditions were found to be temperature 60 °C, time 72 h and volume 200 μl. Antiadhesion test of the undoped (SG) and ZnO-NP doped TEOS sol-gel (ZNSG) coatings were evaluated using marine biofilm forming bacteria. ZNSG coatings exhibited highest biofilm inhibition (89.2%) represented by lowest OD value against Pseudomonasotitidis strain NV1. PMID:26838903

  13. Zn/ZnO core/shell nanoparticles synthesized by laser ablation in aqueous environment: Optical and structural characterizations

    Indian Academy of Sciences (India)

    S C Singh; R K Swarnkar; R Gopal

    2010-02-01

    Zn/ZnO core/shell nanoparticles are synthesized by pulsed laser ablation (PLA) of Zn metal plate in the aqueous environment of sodium dodacyl sulfate (SDS). Solution of nanoparticles is found stable in the colloidal form for a long time, and is characterized by UV-visible absorption, transmission electron microscopy (TEM), photoluminescence (PL) and Raman spectroscopic techniques. UV-visible absorption spectrum has four peaks at 231, 275, 356, and 520 nm, which provides primary information about the synthesis of core-shell and elongated nanoparticles. TEM micrographs reveal that synthesized nanoparticles are monodispersed with three different average sizes and size distributions. Colloidal solution of nanoparticles has significant absorption in the green region, therefore, it absorbs 514.7 nm light of Ar+ laser and emits in the blue region centred at 350 and 375 nm, violet at 457 nm and green at 550 nm regions. Raman shift is observed at 300 cm-1 with PL spectrum, which corresponds to ${}^{3}$2N and 3L mode of vibrations of ZnO shell layer. Synthesis mechanism of Zn/ZnO core/shell nanoparticles is discussed.

  14. Magnetic and dielectric properties of HoMnO{sub 3} nanoparticles synthesized by the polymerized complex method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianguo, E-mail: liuxianguohugh@gmail.com [School of Materials Science and Engineering, Anhui University of technology, Ma' anshan, Anhui 243002 (China); Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Or, Siu Wing, E-mail: eeswor@polyu.edu.hk [Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Sun, Yuping [Center for Engineering practice and Innovation Education, Anhui University of technology, Ma' anshan, Anhui 243002 (China); Jin, Chuangui; Lv, Yaohui [School of Materials Science and Engineering, Anhui University of technology, Ma' anshan, Anhui 243002 (China); Wu, Yuxi [Institute of Molecular Engineering and Applied Chemistry, Anhui University of Technology, Ma' anshan, Anhui 243002 (China)

    2013-06-15

    In this paper, we report on the magnetic and dielectric properties of HoMnO{sub 3} nanoparticles with different size synthesized by a polymerized complex method have been investigated. The HoMnO{sub 3} nanoparticles crystallized in hexagonal perovskite-type structure. The zero-field-cooled magnetic susceptibility curve of HoMnO{sub 3} nanoparticles with averaged size of 30 nm shows that complicated magnetic transitions occurred in a temperature range from 2 to 100 K, which was confirmed by magnetic hysteresis loops. With increasing the particle size, the antiferromagnetic (AFM) transition temperature increases from 56 to 77 K, due to the reduced surface-to-volume ratio. Moreover, with a decrease in particle size, the Mn-spin reorientation temperature (T{sub SR}) is enhanced from 44 to 48 K. - Highlights: • HoMnO{sub 3} nanoparticles have been synthesized by a polymerized complex method. • The magnetic properties of HoMnO{sub 3} nanoparticles have been investigated. • The dielectric properties of HoMnO{sub 3} nanoparticles have been investigated. • The antiferromagnetic transition temperature increases with the particle size.

  15. Simple Method of Synthesizing Nickel-Nitrilotriacetic Acid Gold Nanoparticles with a Narrow Size Distribution for Protein Labeling

    Science.gov (United States)

    Kitai, Toshiyuki; Watanabe, Yuta; Toyoshima, Yoko Y.; Kobayashi, Takuya; Murayama, Takashi; Sakaue, Hiroyuki; Suzuki, Hitoshi; Takahagi, Takayuki

    2011-09-01

    We developed a simple method to synthesize nickel-nitrilotriacetic acid gold nanoparticles (Ni-NTA Au NPs) with a narrow size distribution for site-specific labeling in protein complexes. Au NPs were synthesized by the reduction of HAuCl4 using trisodium citrate and tannin acid. Then, the nanoparticle surfaces were modified with NTA and subsequent complexation with Ni2+. The mean diameter of the synthesized Ni-NTA Au NPs was 4.3 nm, and the coefficient of variation was 9%. The specific binding of the Ni-NTA Au NPs to polyhistidine-tagged (His-tagged) proteins was determined by transmission electron microscopy using kinesin and the p62 subunit of dynactin. Consequently, our method is useful for analyzing the substructures of protein complexes.

  16. Nanoscale size effect on surface spin canting in iron oxide nanoparticles synthesized by the microemulsion method

    International Nuclear Information System (INIS)

    Uniformly sized and crystalline iron oxide nanoparticles (IONPs) with spinel structure and mean diameters of about 3, 6 and 9 nm were synthesized in high yield using the microemulsion route at room temperature. The nanoparticles (NPs) were stabilized in situ by organic surfactant molecules which acted both as a stabilizer of the microemulsion system and as a capping layer of the NP surface. NP size control was attained by careful adjustment of the preparation conditions. The structure, morphology and NP size distribution were investigated by x-ray diffraction, transmission electron microscopy and scanning electron microscopy. A particular effort was devoted in this work to study the effect of size and capping of these NPs on their magnetic structure by in-field Mössbauer spectroscopy at 4.2 K. The mean canting angle (relative to the applied field direction) of the Fe spins was observed to increase with decreasing NP size due to the enhanced surface-to-volume ratio. Comparing bare and capped NPs of the same diameter, we verified that the spin canting was not affected by the organic capping. This implied almost identical magnetic orientations of bare and capped NPs. Simultaneously, the capping material was capable of preventing agglomeration effects which can occur in case of direct particle contact. Using a core/shell model, we showed that spin canting originated from the surface shell of the NPs. Furthermore, the Mössbauer spectral parameters provided evidence for the existence of a high fraction of Fe3O4 (magnetite) in the IONP. (paper)

  17. Biodistribution of gold nanoparticles synthesized by γ-irradiation after intravenous administration in mice

    Science.gov (United States)

    Luan Le, Quang; Phuong Linh Do, Thi; Phuong Uyen Nguyen, Huynh; Phu Dang, Van; Hien Nguyen, Quoc

    2014-06-01

    In the present research work we evaluate the in vivo distribution of gold nanoparticles (AuNPs) at different time durations after intravenous administration in mice. AuNPs with size of about 20 nm and concentration of 1 mM were synthesized by gamma irradiation method using 0.5% alginate as a stabilizer. AuNPs were characterized by UV-Vis spectrum and transmission electron microscope (TEM) image. The as-synthesized AuNPs solution was centrifuged to concentrate to 2 mg AuNPs/1 ml solution. Intravenous administration of AuNPs in mice was done at the tail with 1 mg AuNPs (0.5 ml). After 1, 3, 6 and 12 h of injection, blood was collected, mice were sacrificed and various tissues/organs were removed. The blood haematology and serum clinical chemistry indexes of mice intravenously injected with AuNPs were not significantly different compared to those of the control ones. In addition, gold content in the samples was quantitatively determined by k0-neutron activation analysis (k0-NAA) at nuclear research reactor, Da Lat Vietnam. Results showed that after 1 h of administration, AuNPs were mainly accumulated in blood (41.56%), in liver (51.60.%), in lung (6.16%) and in kidney (0.53%). After that the content of AuNPs in blood was decreased to nearly normal at 6 h while the content of AuNPs in liver, lung and kidney was accumulatively increased. After 6 h of administration AuNPs were mainly accumulated in organs like liver (76.33%), lung (11.86%) and kidney (2.23%). Thus, the obtained results are practically useful for using AuNPs as x-ray contrast agent, especially for blood and liver.

  18. Photocatalytic activity of biogenic silver nanoparticles synthesized using yeast ( Saccharomyces cerevisiae) extract

    Science.gov (United States)

    Roy, Kaushik; Sarkar, C. K.; Ghosh, C. K.

    2015-11-01

    Synthesis of metallic and semiconductor nanoparticles through physical and chemical route is quiet common but biological synthesis procedures are gaining momentum due to their simplicity, cost-effectivity and eco-friendliness. Here, we report green synthesis of silver nanoparticles from aqueous solution of silver salts using yeast ( Saccharomyces cerevisiae) extract. The nanoparticles formation was gradually investigated by UV-Vis spectrometer. X-ray diffraction analysis was done to identify different phases of biosynthesized Ag nanoparticles. Transmission electron microscopy was performed to study the particle size and morphology of silver nanoparticles. Fourier transform infrared spectroscopy of the nanoparticles was performed to study the role of biomolecules capped on the surface of Ag nanoparticles during interaction. Photocatalytic activity of these biosynthesized nanoparticles was studied using an organic dye, methylene blue under solar irradiation and these nanoparticles showed efficacy in degrading the dye within a few hours of exposure.

  19. Solar photocatalytic degradation of RB5 by ferrite bismuth nanoparticles synthesized via ultrasound.

    Science.gov (United States)

    Soltani, T; Entezari, M H

    2013-09-01

    In this paper, the photocatalytic degradation of Reactive Black 5 (RB5) was investigated with ferrite bismuth synthesized via ultrasound under direct sunlight irradiation. The intensity of absorption peaks of RB5 gradually decreased by increasing the irradiation time and finally vanished in 50 min in acidic medium. The formation of new intermediate was observed in basic medium. The relative concentration of RB5 in solution and on the surface of ferrite bismuth (BiFeO3) nanoparticles was considered during the experiment in acidic and basic media. The effects of various parameters such as amount of catalyst, concentration of dye, and pH of the solution have been studied on the dye degradation. The adsorption isotherm and the kinetic of photocatalytic degradation of RB5 were investigated. The adsorption constants in the dark and in the presence of sunlight irradiation were compared. The photocatalytic degradation mechanism of RB5 has been evaluated through the addition of some scavengers to the solution. In addition, the stability and reusability of the catalyst were examined in this work.

  20. Ferromagnetism in chemically synthesized CeO2 nanoparticles by Ni doping

    Energy Technology Data Exchange (ETDEWEB)

    Thurber, A.; Reddy, K. M.; Shutthanandan, V.; Engelhard, Mark H.; Wang, Chong M.; Hays, Jason; Punnoose, Alex

    2007-10-24

    This work reports the discovery of room-temperature ferromagnetism in 5 - 9 nm sized Ce1-xNixO2 nanoparticles (0.01 ≤ x ≤ 0.10) prepared using a sol-gel based chemical method at room temperature and under ambient conditions. Particle induced x-ray emission studies were used to determine the dopant concentrations. Magnetic measurements of the chemically synthesized Ce1-xNixO2 samples at room temperature showed coercivity in the 40 - 120 Oe range, and the saturation magnetization showed a maximum of 1.21 memu/g (8.59×10-4 μB/Ni ion) for x = 0.04. Average crystallite sizes and lattice parameters estimated from x-ray diffraction and transmission electron microscopy studies showed a gradual decrease with x in the entire doping range while the lattice strain showed a minimum for x = 0.04. Optical studies revealed direct band gap energies ranging from 3.23 to 3.99 eV with a minimum for x = 0.04. A high Curie temperature of TC = 550 K was obtained for x = 0.04.

  1. Optical and vibrational properties of PbSe nanoparticles synthesized in clinoptilolite

    Science.gov (United States)

    Flores-Valenzuela, J.; Cortez-Valadez, M.; Ramírez-Bon, R.; Arizpe-Chavez, H.; Román-Zamorano, J. F.; Flores-Acosta, M.

    2015-08-01

    In this work, the optical and vibrational properties of composites based on PbSe semiconductor immersed in a zeolite matrix are reported. The natural zeolite, (clinoptilolite) was used as the host material of PbSe nanoparticles. The method for obtaining these particles is also reported here, which is based on ion exchange processes inside the natural zeolite in alkaline aqueous solution that contains the precursor ions Pb2+ and Se2-. The process of synthesis was conducted temperature, volume, concentration and reaction time of the precursors. The samples were studied by powder X-ray diffraction, TEM (transmission electron microscopy), diffuse reflectance and Raman spectroscopy. The experimental results demonstrate that with this method, the particles with nanometric PbSe sizes were synthesized in the zeolite matrix. Vibrational Raman bands at low wave numbers were detected in these particles by the presence of a shoulder located at 135 cm-1 and a band at around 149 cm-1. The vibrational calculations for small clusters of PbSe at LSDA (Local Spin Density Approximation) level combined with the basis set LANDL2DZ (Los Alamos National Laboratory 2 double ζ), were considered through DFT (Density Functionl Theory). The "breathing" Raman modes located at 119-152 cm-1 were detected for this level of theory.

  2. Antimicrobial potential of green synthesized CeO2 nanoparticles from Olea europaea leaf extract

    Science.gov (United States)

    Maqbool, Qaisar; Nazar, Mudassar; Naz, Sania; Hussain, Talib; Jabeen, Nyla; Kausar, Rizwan; Anwaar, Sadaf; Abbas, Fazal; Jan, Tariq

    2016-01-01

    This article reports the green fabrication of cerium oxide nanoparticles (CeO2 NPs) using Olea europaea leaf extract and their applications as effective antimicrobial agents. O. europaea leaf extract functions as a chelating agent for reduction of cerium nitrate. The resulting CeO2 NPs exhibit pure single-face cubic structure, which is examined by X-ray diffraction, with a uniform spherical shape and a mean size 24 nm observed through scanning electron microscopy and transmission electron microscopy. Ultraviolet-visible spectroscopy confirms the characteristic absorption peak of CeO2 NPs at 315 nm. Fourier transform infrared spectroscopy reflects stretching frequencies at 459 cm−1, showing utilization of natural components for the production of NPs. Thermal gravimetric analysis predicts the successful capping of CeO2 NPs by bioactive molecules present in the plant extract. The antimicrobial studies show significant zone of inhibition against bacterial and fungal strains. The higher activities shown by the green synthesized NPs than the plant extract lead to the conclusion that they can be effectively used in biomedical application. Furthermore, reduction of cerium salt by plant extract will reduce environmental impact over chemical synthesis.

  3. Antibacterial and Antioxidant Activities of ZnO Nanoparticles Synthesized Using Extracts of Allium sativum, Rosmarinus officinalis and Ocimum basilicum

    Institute of Scientific and Technical Information of China (English)

    Manuela Stan; Adriana Popa; Dana Toloman; Teofil-Danut Silipas; Dan Cristian Vodnar

    2016-01-01

    ZnO nanoparticles (ZnO NPs) were synthesized by chemical method (coprecipitation) and biological method using aqueous extracts of garlic (Allium sativum),rosemary (Rosmarinus officinalis) and basil (Ocimum basilicum).The influence of plant extract on the antibacterial and antioxidant activities of green synthesized nanoparticles was investigated.The X-ray diffraction studies reveal that all ZnO samples have hexagonal wurtzite structure.The particle size of ZnO NPs estimated by transmission electron microscopy analysis (between 14 and 27 nm) varies depending on the synthesis method of nanoparticles and the type of extracts from the plants used.The functional groups involved in the biosynthetic procedure were evidenced by Fourier transform infrared spectroscopy.The presence of Mn2+ ions,Zn vacancy complexes and oxygen vacancies in ZnO samples was highlighted by electron paramagnetic resonance spectroscopy.The green synthesized ZnO NPs have shown a good bactericidal activity against Staphylococcus aureus,Bacillus subtilis,Listeria monocytogenes,Escherichia coli,Salmonella typhimurium and Pseudomonas aeruginosa bacterial strains.ZnO NPs synthesized using extracts of the selected plant species have been found to exhibit more enhanced antibacterial and antioxidant activities as compared to chemical ZnO NPs.

  4. Optical and Structural Properties of ZnO Nanoparticles Synthesized by CO2 Microwave Plasma at Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    Se Min Chun

    2014-01-01

    Full Text Available The results of carbon-doped zinc oxide nanoparticles synthesized by CO2 microwave plasma at atmospheric pressure are presented. The 2.45-GHz microwave plasma torch and feeder for injecting Zn granules are used in the synthesis of zinc oxide nanoparticles. The Zn granules (13.5 g/min were introduced into the microwave plasma by CO2 (5 l/min swirl gas. The microwave power delivered to the CO2 microwave plasma was 1 kW. The synthesis of carbon-doped zinc oxide nanoparticles was carried out in accordance with CO2 + Zn → carbon-doped ZnO + CO. The synthesized carbon-doped zinc oxide nanoparticles have a high purity hexagonal phase. The absorption edge of carbon-doped zinc oxide nanoparticles exhibited a red shift from a high-energy wavelength to lower in the UV-visible spectrum, due to band gap narrowing. A UV-NIR spectrometer, X-ray diffraction, emission scanning electron-microscopy, energy dispersive X-ray microanalysis, Fourier transform infrared spectroscopy, and a UV-Vis-NIR spectrophotometer were used for the characterization of the as-produced products.

  5. Newly Synthesized Water Soluble Cholinium-Purpurin Photosensitizers and Their Stabilized Gold Nanoparticles as Promising Anticancer Agents

    Directory of Open Access Journals (Sweden)

    Young Key Shim

    2008-05-01

    Full Text Available For possible future use in Photodynamic Therapy (PDT and/or Photothermal Therapy (PTT of cancer and screening of cancer cells a new type of ionic liquid photosensitizer –Cholinium-Purpurin-18 (Chol-Pu-18 – was synthesized and small gold (Au nanoparticles, stabilized by this photosensitizer were prepared without adding any particular reducing agents and CTAB. UV-Vis spectroscopy and Transmission Electron Microscopy (TEM were used for characterization of the nanoparticles and FAB-MS and NMR of the ionic liquid choline hydroxide, purpurin carboxylate and their ionic liquid type of photosensitizer were obtained.

  6. X-ray absorption spectroscopy characterization of iron-oxide nanoparticles synthesized by high temperature plasma processing

    International Nuclear Information System (INIS)

    Iron-oxide nanoparticles have been synthesized by high temperature arc plasma route with different plasma currents and characterized for their structure, morphology and local atomic order. Fe K-edge x-ray absorption spectra reveal distinct local structure of the samples grown with different plasma currents. We have shown that the local disorder is higher for the higher plasma current grown samples that also have a larger average particle-size. The results provide useful information to control structural and morphological properties of nanoparticles grown by high temperature plasma synthesis process

  7. Using Glutamic Acid, Phenylalanine and Tryptophan to Synthesize Capped Gold Nanoparticles

    OpenAIRE

    Kamyar Khoshnevisan; Mohammad Barkhi; Nasim Bararpour; Shahram Tangestaninejad; Azim Akbarzadeh; Davood Zare

    2011-01-01

    Introduction: The study and investigation of gold nanoparticles produced by amino acid is one of the interesting and applied issues in nanotechnology. In this study, amino acids were used to reduce gold cations as well as an agent to cap gold nanoparticles. In fact, strong bound of amino groups to amino acid and protein on the gold nanoparticles surface indicate the medical applications of these materials. Methods: In this study, gold nanoparticles were prepared and functionalized by using so...

  8. Phase transformations of high-purity PbI2 nanoparticles synthesized from lead-acid accumulator anodes

    Science.gov (United States)

    Malevu, T. D.; Ocaya, R. O.; Tshabalala, K. G.

    2016-09-01

    High-purity hexagonal lead iodide nanoparticles have been synthesized from a depleted sealed lead acid battery anode. The synthesized product was found to consist of the rare 6R polytype form of PbI2 that is thought to have good potential in photovoltaic applications. We investigate the effects of annealing time and post-melting temperature on the structure and optical properties using 1.5418 Å CuKα radiation. Photoluminescence measurements were done under 150 W/221 nm wavelength xenon excitation. Phase transformation was observed through XRD peaks when annealing time increased from 0.5-5 h. The nanoparticle grain size and inter-planar distance appeared to be independent of annealing time. PL measurements show three broad peaks in a range of 400 nm to 700 nm that are attributed to excitonic, donor-acceptor pair and luminescence bands from the deep levels.

  9. Properties of Er{sub 2}O{sub 3} nanoparticles synthesized by a modified co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda C, J.; Maranon R, V. F.; Perez Ladron de G, H.; Rodriguez R, R. A.; Chiu Z, R. [Universidad de Guadalajara, Centro Universitario de los Lagos, Av. Enrique Diaz de Leon s/n, Lagos de Moreno 47460, Jalisco (Mexico); Meneses N, M. A., E-mail: jcc050769@yahoo.com.mx [Centro de Investigaciones en Optica, A. C., Apdo. Postal 1-948, Leon, Guanajuato (Mexico)

    2015-07-01

    Er{sub 2}O{sub 3} nanoparticles were synthesized by co-precipitation with the addition of ascorbate as stabilizing agent. The nanoparticles had spherical shapes with a mean diameter of 32 nm and were allocated in clusters, as determined by X-ray diffraction, atomic force microscopy and optical microscopy. Characteristic green and red emissions from Er{sup 3+} were recorded by pumping the nanoparticles at 525 nm, 805 nm and 975 nm. However, the luminescence spectra show an enhancement of red emission for Nir pump wavelengths. We proposed this behavior was due to phonon-assisted depopulation mechanisms and energy transfer processes related to the different excitation schemes. (Author)

  10. Band gap engineering and enhanced photoluminescence of Mg doped ZnO nanoparticles synthesized by wet chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Arshad, Mohd; Meenhaz Ansari, Mohd [Department of Applied Physics, Aligarh Muslim University, Aligarh (India); Ahmed, Arham S. [Department of Physics, Aligarh Muslim University, Aligarh (India); Tripathi, Pushpendra [Department of Applied Physics, Aligarh Muslim University, Aligarh (India); Ashraf, S.S.Z. [Department of Physics, Aligarh Muslim University, Aligarh (India); Naqvi, A.H. [Department of Applied Physics, Aligarh Muslim University, Aligarh (India); Azam, Ameer, E-mail: azam222@rediffmail.com [Department of Applied Physics, Aligarh Muslim University, Aligarh (India)

    2015-05-15

    In the present investigations Mg doped ZnO nanoparticles were synthesized using sol–gel method. Mg doping in nanoparticles was found to be a good method for tuning of band gap and photoluminescence of ZnO nanoparticles. Simultaneously, Mg doping also inhibited the growth of particle size and it decreased from 36.1 to 13.5 nm with the increase in doping concentration from 0% to 12%. Optical band gap was found to increase from 3.23 to 3.47 eV and photoluminescence studies revealed that visible PL emission was enhanced with doping concentration. - Highlights: • Significant decrease in particle size with Mg doping. • Increase in band gap with Mg doping. • Enhanced luminescence as a result of Mg doping.

  11. THERMODYNAMIC ANALYSIS AND EXPERIMENTAL VERIFICATION FOR SYNTHESIZING SILICON NITRIDE NANOPARTICLES USING RF PLASMA CVD

    Institute of Scientific and Technical Information of China (English)

    Ruoyu Hong; Jianmin Ding; Hongzhong Li

    2003-01-01

    Silicon nitride nanoparticles were synthesized by radio-frequency (RF) plasma chemical vapor deposition (PCVD) using silicon tetrachloride and ammonia as precursors, and argon as carrier gas. By assuming chemical thermodynamic equilibrium in the system, a computer program based on chemical thermodynamics was used to calculate the compositions of the system at different initial concentrations and final temperatures. At first, five elements and thirty-four species were considered. The effects of temperatures, and concentrations of ammonia, hydrogen and nitrogen on the equilibrium compositions were analyzed. It was found that the optimal reaction temperature range should be 1200 to 1500 K to obtain the highest conversion and yield of Si3N4. The inlet position of ammonia should be lower than that of silicon tetrachloride, and both should be located at the tail of the plasma torch. The best mole ratio of ammonia to silicon tetrachloride was found to be about 6. Later, the influences of water (and oxygen) were considered, and 17 additional species were included in the computations. It was found that oxygen or water content in the raw materials should be as low as possible in order to have high nitride content in the produced Si3N4. Nitrogen or hydrogen might be used to replace some or even all the argon to improve the yield of silicon nitride and reduce the cost. The ratio of ammonia to silicon tetrachloride should be high enough to obtain high conversion, but not excessively high to reduce the oxygen content due to the existence of water in ammonia. The simulated results were verified by experiments.

  12. Screening Antimicrobial Activity of Nickel Nanoparticles Synthesized Using Ocimum sanctum Leaf Extract

    Directory of Open Access Journals (Sweden)

    Chitra Jeyaraj Pandian

    2016-01-01

    Full Text Available Antimicrobial efficacy of nickel nanoparticles synthesized using leaf extract of Ocimum sanctum (NiGs was investigated against pathogenic Gram-negative (E. coli, K. pneumoniae, and S. typhi, Gram-positive (B. subtilis, S. epidermidis bacteria and fungi (C. albicans, C. tropicalis, A. fumigatus, A. clavatus, and A. niger. 100 µg/mL NiGs showed maximum antimicrobial activity against tested pathogens compared to leaf extract and antibiotics. E. coli (25 mm and C. albicans (23 mm exhibited higher zone of inhibition at 100 µg/mL NiGs. MIC, MBC, and MFC values of NiGs against all tested pathogens ranged between 25 and 50 µg/mL. Growth of bacterial and fungal cells (105 cfu/mL was completely inhibited at 50 µg/mL NiGs. E. coli and C. albicans have showed strong antimicrobial activity with 81% and 50% reactive oxygen species (ROS production, 30 and 16 µg/mL protein leakage, and 95 and 82 U/L LDH leakages, respectively. Gram-negative bacteria and Candida species showed more sensitivity to NiGs at all concentrations tested (25–100 µg/mL than Gram-positive bacteria and Aspergillus species, respectively. Microbial growth in the presence of NiGs and ascorbic acid confirmed the involvement of ROS in antimicrobial activity. Hence, NiGs induced ROS generation was attributed to the protein and LDH leakage from microbial membranes.

  13. Catalytic and synergistic antibacterial potential of green synthesized silver nanoparticles: Their ecotoxicological evaluation on Poecillia reticulata.

    Science.gov (United States)

    Borase, Hemant P; Patil, Chandrashekhar D; Salunkhe, Rahul B; Suryawanshi, Rahul K; Salunke, Bipinchandra K; Patil, Satish V

    2014-01-01

    In the present study, stable silver nanoparticles (AgNPs) were fabricated at a rapid rate from leaf extract of medicinally important plant Alstonia macrophylla. Biosynthesized AgNPs are of spherical shape and narrow size (70 nm), exhibiting a surface plasmon resonance peak at 435 nm, and a zeta potential of -30.8 mV and have a crystalline nature. A diverse biochemical consortium of protein, terpenoids, phenolics, and flavonoids in leaf extract of A. macrophylla was found to be responsible for AgNP synthesis as evidenced from qualitative-quantitative chemical analysis and Fourier transform infrared spectroscopy studies. Nitroaromatic compounds are anthropogenic pollutants with long-lasting environmental persistence and are needed to transform into less toxic derivatives. 4-Nitrophenol and p-nitroaniline were reduced to less hazardous and commercially useful 4-aminophenol and p-phenylenediamine by phytosynthesized AgNPs. Rate constants of 0.052 and 0.040 Min(-1) were calculated for 4-nitrophenol and p-nitroaniline reduction, respectively. Thin-layer chromatography also confirms the reduction of these nitroaromatic compounds. Combinational studies could be one of the strategies to overcome microbial resistance to antibiotics. In synergistic antibacterial assay, the highest increase in a fold area of 3.84 was reported against Staphylococcus aureus using a combination of AgNPs with penicillin. Biosynthesized AgNPs were found to be less toxic (LC50 = 9.13 ppm) than chemically synthesized AgNPs having a LC50 value of 2.86 ppm against nontarget fish Poecillia reticulata. Our green nanosynthesis method offers a faster rate of formation of stable AgNPs having antibacterial and catalytic potential with lower environmental toxicity.

  14. Facile approach to synthesize magnesium oxide nanoparticles by using Clitoria ternatea—characterization and in vitro antioxidant studies

    Science.gov (United States)

    John Sushma, N.; Prathyusha, D.; Swathi, G.; Madhavi, T.; Deva Prasad Raju, B.; Mallikarjuna, K.; Kim, Hak-Sung

    2016-03-01

    Facile approach to synthesize the metal oxide nanoparticles is getting an increased attention in various biomedical applications such as, to treat antibiotic resistant diseases. Magnesium oxide nanoparticles (MgO·NPs) were synthesized by using Clitoria ternatea as the stabilizer in a green synthesis approach. The preliminary screening of MgO·NPs in the presence of C. ternatea extract was observed by UV-visible spectrophotometer. X-ray diffraction (XRD) pattern have proved the crystalline nature of the MgO·NPs; Photoluminescence (PL) measurement studies are used to identify the quality and defects in the crystal structure. FE-SEM with EDS has showed the size of 50-400 nm with specific binding energies. FT-IR has revealed the functional groups present in the plant extract and the peak at 521 cm-1 indicated the characteristic absorption bands of MgO·NPs. The DPPH activity and reducing power assay of biologically synthesized MgO·NPs could reach 65 % at a concentration of 150 µg/ml, respectively. From the results it was concluded that the biologically synthesized MgO·NPs exhibit good antioxidant activity.

  15. Tunability of Size and Magnetic Moment of Iron Oxide Nanoparticles Synthesized by Forced Hydrolysis

    Directory of Open Access Journals (Sweden)

    Ben Sutens

    2016-07-01

    Full Text Available To utilize iron oxide nanoparticles in biomedical applications, a sufficient magnetic moment is crucial. Since this magnetic moment is directly proportional to the size of the superparamagnetic nanoparticles, synthesis methods of superparamagnetic iron oxide nanoparticles with tunable size are desirable. However, most existing protocols are plagued by several drawbacks. Presented here is a one-pot synthesis method resulting in monodisperse superparamagnetic iron oxide nanoparticles with a controllable size and magnetic moment using cost-effective reagents. The obtained nanoparticles were thoroughly characterized by transmission electron microscopy (TEM, X-ray diffraction (XRD and Fourier transform infrared (FT-IR measurements. Furthermore, the influence of the size on the magnetic moment of the nanoparticles is analyzed by superconducting quantum interference device (SQUID magnetometry. To emphasize the potential use in biomedical applications, magnetic heating experiments were performed.

  16. Magnetic and Mössbauer spectroscopic studies of NiZn ferrite nanoparticles synthesized by a combustion method

    Science.gov (United States)

    Sreeja, V.; Vijayanand, S.; Deka, S.; Joy, P. A.

    2008-04-01

    The properties of nanocrystalline Ni0.5Zn0.5Fe2O4 synthesized by an auto-combustion method have been investigated by magnetic measurements and Mössbauer spectroscopy. The as-synthesized single phase nanosized ferrite powder is annealed at different temperatures in the range 673 1,273 K to obtain nanoparticles of different sizes. The powders are characterized by powder X-ray diffraction, vibrating sample magnetometer, transmission electron microscopy and Mössbauer spectroscopy. The as-synthesized powder with average particle size of ~9 nm is superparamagnetic. Magnetic transition temperature increases up to 665 K for the nanosized powder as compared to the transition temperature of 548 K for the bulk ferrite. This has been confirmed as due to the abnormal cation distribution, as evidenced from room temperature Mössbauer spectroscopic studies.

  17. Structural and photoluminescence studies of TiO{sub 2} nanoparticles synthesized by solution combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Balamurugan, M., E-mail: chem.muruga@gmail.com; Silambarasan, M. [Centre for Photonics and Nanotechnology, Department of Science, Sona College of Technology, Salem – 636 005, Tamilnadu (India); Saravanan, S. [Centre for Photonics and Nanotechnology, Department of Science, Sona College of Technology, Salem – 636 005, Tamilnadu (India); Department of Frontier Materials, Nagoya Institute of Technology, Nagoya - 466-8555 (Japan); Soga, Tetsuo [Department of Frontier Materials, Nagoya Institute of Technology, Nagoya - 466-8555 (Japan)

    2015-06-24

    In this study titanium dioxide nanoparticle is prepared by simple solution combustion method. The powder X-ray diffraction pattern indicates the prepared titanium dioxide nanoparticles crystalline nature with tetragonal structure. Also it shows the nanoparticle is anatase and rutile mixed phase. The Field Emission Scanning Electron Microscopy image shows the nanostructure of particles in the size range about 50 nm. Room temperature photoluminescence shows intrinsic defects of oxygen vacancies.

  18. Structural and photoluminescence studies of TiO2 nanoparticles synthesized by solution combustion method

    International Nuclear Information System (INIS)

    In this study titanium dioxide nanoparticle is prepared by simple solution combustion method. The powder X-ray diffraction pattern indicates the prepared titanium dioxide nanoparticles crystalline nature with tetragonal structure. Also it shows the nanoparticle is anatase and rutile mixed phase. The Field Emission Scanning Electron Microscopy image shows the nanostructure of particles in the size range about 50 nm. Room temperature photoluminescence shows intrinsic defects of oxygen vacancies

  19. Bismuth nanoparticles synthesized by laser ablation in lubricant oils for tribological tests

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Castañeda, M., E-mail: mar.floc@hotmail.com [Universidad Autónoma del Estado de México, Av. Instituto Literario No. 100, Oriente Col. Centro, Toluca, Estado de México C.P. 50000, México (Mexico); Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa, Ocoyoacac, Edo. de México C.P. 52750, México (Mexico); Camps, E. [Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa, Ocoyoacac, Edo. de México C.P. 52750, México (Mexico); Camacho-López, M. [Universidad Autónoma del Estado de México, Av. Instituto Literario No. 100, Oriente Col. Centro, Toluca, Estado de México C.P. 50000, México (Mexico); Muhl, S. [Instituto de Investigación en Materiales (UNAM), Circuito Exterior, Ciudad Universitaria, Coyoacán, 04510 México, D.F., México (Mexico); and others

    2015-09-15

    Highlights: • Bismuth nanoparticles have been obtained by laser ablation of solids in liquids. • The technique allows controlling the size and concentration of the samples. • Bi np’s in base oils can improve the tribological characteristics of the lubricant. - Abstract: The improvement of the tribological properties of mineral base oils through the addition of bismuth nanoparticles as an additive, together with the idea of obtaining lubricants free of heavy metals, was evaluated. Bismuth nanoparticles were produced directly in the heavy and light viscosity mineral base oils (BS900 and BS6500) using the technique of laser ablation of solids immersed in liquids. Transmission electron microscopy measurements showed the presence of pure bismuth nanoparticles. Small Angle X-ray Scattering (SAXS) measurements showed that the average size of the nanoparticles was between 7 and 65 nm depending on the experimental conditions used. The tribological properties of the base oil with the bismuth nanoparticles additives were evaluated using a four-ball tester. Tests were performed using the base oil with and without Bi nanoparticles. It was observed that the coefficient of friction of the oil decrease with an increasing concentration of the nanoparticles. The results also showed that the wear rate was reduced when the Bi nanoparticle additives were used.

  20. Evaluation of leaf aqueous extract and synthesized silver nanoparticles using Nerium oleander against Anopheles stephensi (Diptera: Culicidae).

    Science.gov (United States)

    Roni, Mathath; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Hwang, Jiang-Shiou

    2013-03-01

    Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and ecofriendly reducing and capping agents. The present study was carried out to establish the larvicidal activity of synthesized silver nanoparticles (AgNPs) using leaf extract of Nerium oleander (Apocynaceae) against the first to fourth instar larvae and pupae of malaria vector, Anopheles stephensi (Diptera: Culicidae). Nanoparticles are being used in many commercial applications. It was found that aqueous silver ions can be reduced by the aqueous extract of the plant parts to generate extremely stable silver nanoparticles in water. The results were recorded from UV-Vis spectrum, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy analysis. The production of the AgNPs synthesized using leaf extract of N. oleander was evaluated through a UV-Vis spectrophotometer in a wavelength range of 200 to 700 nm. This revealed a peak at 440 nm in N. oleander leaf extracts, indicating the production of AgNPs. The FTIR spectra of AgNPs exhibited prominent peaks at 509.12 cm(-1) (C-H bend alkenes), 1,077.05 cm(-1) (C-O stretch alcohols), 1,600.63 cm(-1) (N-H bend amines), 2,736.49 and 2,479.04 cm(-1) (O-H stretch carboxylic acids), and 3,415.31 cm(-1) (N-H stretching due to amines group). An SEM micrograph showed 20-35-nm-size aggregates of spherical- and cubic-shaped nanoparticles. EDX showed the complete chemical composition of the synthesized nanoparticles of silver. Larvicidal activity of aqueous leaf extract of N. oleander and synthesized AgNPs was carried out against Anopheles stephensi, and the results showed that the highest larval mortality was found in the synthesized AgNPs against the first to fourth instar larvae and pupae of Anopheles stephensi with the following values: LC(50) of instar larvae 20.60, 24.90, 28.22, and 33.99 ppm; LC(90) of instar larvae 41.62, 50.33, 57.78, and 68.41

  1. Characterization, antioxidant and cytotoxicity evaluation of green synthesized silver nanoparticles using Cleistanthus collinus extract as surface modifier

    International Nuclear Information System (INIS)

    Graphical abstract: The figure is the TEM image of green synthesized silver nanoparticles from Cleistanthus collinus. In this investigation we have used the poisonous plant as a reducing and capping agent. This is a first time data to synthesis the metal nanoparticles using poisonous plant. - Highlights: • A hitherto unreported venomous plant mediated AgNPs synthesis. • The particle size is observed in the range of 20–40 nm. • Surface morphology of the well-dispersed silver nanoparticles is studied using SEM and TEM. • Crystalline nature of AgNPs is confirmed by X-ray diffraction analysis. • Antioxidant activities of green synthesized AgNPs are tested in vitro. - Abstract: We report, here a simple green method for the preparation of silver nanoparticles (AgNPs) using the plant extract of Cleistanthus collinus as potential phyto reducer. The synthesized AgNPs were characterized by UV–vis spectra, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained results confirmed that the AgNPs were crystalline in nature and the morphological studies reveal the spherical shape of AgNPs with size ranging from 20 to 40 nm. The in vitro antioxidant activity of AgNPs showed a significant effect on scavenging of free radicals. The cytotoxicity study exhibited a dose-dependent effect against human lung cancer cells (A549) and normal cells (HBL-100), the inhibitory concentration (IC50) were found to be 30 μg/mL and 60 μg/mL respectively. The in vivo histopathology of mouse organs proved that AgNPs does not possess toxic effect and can be extensively applied in biomedical sciences

  2. Cytotoxic effect of magnetic iron oxide nanoparticles synthesized via seaweed aqueous extract

    Directory of Open Access Journals (Sweden)

    Namvar F

    2014-05-01

    Full Text Available Farideh Namvar,1,2 Heshu Sulaiman Rahman,3,4 Rosfarizan Mohamad,1,5 Javad Baharara,2 Mahnaz Mahdavi,6 Elaheh Amini,7 Max Stanley Chartrand,8 Swee Keong Yeap31Institute of Tropical Forestry and Forest Products, Universiti Putra Malaysia, Selangor, Malaysia; 2Research Center for Animal Development Applied Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran; 3Institute of Bioscience, 4Department of Microbiology and Pathology, Faculty of Veterinary Medicine, 5Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Selangor, Malaysia; 6Department of Chemistry, Faculty of Science, Islamic Azad University, Shiraz Branch, Shiraz, 7Kharazmi University, Tehran, Iran; 8DigiCare Behavioral Research, Casa Grande, AZ, USAAbstract: Magnetic iron oxide nanoparticles (Fe3O4 MNPs are among the most useful metal nanoparticles for multiple applications across a broad spectrum in the biomedical field, including the diagnosis and treatment of cancer. In previous work, we synthesized and characterized Fe3O4 MNPs using a simple, rapid, safe, efficient, one-step green method involving reduction of ferric chloride solution using brown seaweed (Sargassum muticum aqueous extract containing hydroxyl, carboxyl, and amino functional groups mainly relevant to polysaccharides, which acts as a potential stabilizer and metal reductant agent. The aim of this study was to evaluate the in vitro cytotoxic activity and cellular effects of these Fe3O4 MNPs. Their in vitro anticancer activity was demonstrated in human cell lines for leukemia (Jurkat cells, breast cancer (MCF-7 cells, cervical cancer (HeLa cells, and liver cancer (HepG2 cells. The cancer cells were treated with different concentrations of Fe3O4 MNPs, and an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay was used to test for cytotoxicity, resulting in an inhibitory concentration 50 (IC50 value of 23.83±1.1

  3. Synthesis of copper/nickel nanoparticles using newly synthesized Schiff-base metals complexes and their cytotoxicity/catalytic activities.

    Science.gov (United States)

    Aazam, Elham S; El-Said, Waleed Ahmed

    2014-12-01

    Transition metal complexes compounds with Schiff bases ligand representing an important class of compounds that could be used to develop new metal-based anticancer agents and as precursors of metal NPs. Herein, 2,3-bis-[(3-ethoxy-2-hydroxybenzylidene)amino]but-2-enedinitrile Schiff base ligand and its corresponding copper/nickel complexes were synthesized. Also, we reported a facile and rapid method for synthesis nickel/copper nanoparticles based on thermal reduction of their complexes. Free ligand, its metal complexes and metals nanoparticles have been characterized based on elemental analysis, transmission electron microscopy, powder X-ray diffraction, magnetic measurements and by various spectroscopic (UV-vis, FT-IR, (1)H NMR, GC-MS) techniques. Additionally, the in vitro cytotoxic activity of free ligand and its complexes compounds were assessed against two cancer cell lines (HeLa and MCF-7 cells)and one healthy cell line (HEK293 cell). The copper complex was found to be active against these cancer cell lines at very low LD50 than the free ligand, while nickel complex did not show any anticancer activity against these cell lines. Also, the antibacterial activity of as-prepared copper nanoparticles were screened against Escherichia coli, which demonstrated minimum inhibitory concentration and minimum bactericidal concentration values lower than those values of the commercial Cu NPs as well as the previous reported values. Moreover, the synthesized nickel nanoparticles demonstrated remarkable catalytic performance toward hydrogenation of nitrobenzene that producing clean aniline with high selectivity (98%). This reactivity could be attributed to the high degree of dispersion of Ni nanoparticles.

  4. Advances of Ag, Cu, and Ag-Cu alloy nanoparticles synthesized via chemical reduction route

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Kim Seah; Cheong, Kuan Yew, E-mail: cheong@eng.usm.my [Universiti Sains Malaysia, Electronic Materials Research Group, School of Materials and Mineral Resources Engineering (Malaysia)

    2013-04-15

    Silver (Ag) and copper (Cu) nanoparticles have shown great potential in variety applications due to their excellent electrical and thermal properties resulting high demand in the market. Decreasing in size to nanometer scale has shown distinct improvement in these inherent properties due to larger surface-to-volume ratio. Ag and Cu nanoparticles are also shown higher surface reactivity, and therefore being used to improve interfacial and catalytic process. Their melting points have also dramatically decreased compared with bulk and thus can be processed at relatively low temperature. Besides, regularly alloying Ag into Cu to create Ag-Cu alloy nanoparticles could be used to improve fast oxidizing property of Cu nanoparticles. There are varieties methods have been reported on the synthesis of Ag, Cu, and Ag-Cu alloy nanoparticles. This review aims to cover chemical reduction means for synthesis of those nanoparticles. Advances of this technique utilizing different reagents namely metal salt precursors, reducing agents, and stabilizers, as well as their effects on respective nanoparticles have been systematically reviewed. Other parameters such as pH and temperature that have been considered as an important factor influencing the quality of those nanoparticles have also been reviewed thoroughly.

  5. Gold nanoparticles synthesized by gamma radiation and stabilized by bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Jessica; Silva, Andressa A.; Geraldes, Adriana N.; Lugao, Ademar B., E-mail: jessicaleal@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Grasselli, Mariano, E-mail: mariano.grasselli@gmail.com [Departamento de Ciencia y Tecnologia, Universidad Nacional de Quilmes, Bernal (Argentina)

    2015-07-01

    Gold nanoparticles (AuNPs) are a new option for pharmaceutical and cosmetic industries due to their interesting chemical, electrical and catalytic properties. Research for cancer treatments have been developed using this promising radiotherapy agent. The challenge of gold nanoparticles is to keep them stable, due to metallic behavior. It is know that surface plasma resonance promotes agglomeration of metallic nanoparticles, but they are not stable. Stabilizers have been used to reduce agglomeration. The aim of this work is reduction of HAuCl{sub 4} salt to AuNPs performed by gamma radiation {sup 60}Co source and the stabilization of gold nanoparticles using bovine serum albumin (BSA) fraction V as stabilizer agent. AuNPs were characterized by UV-visible to verify the nanoparticles formation. Samples containing BSA and samples obtained by the conventional method (without stabilizer) were monitored for two weeks and analyzed. Results were compared. (author)

  6. Gold nanoparticles synthesized by Brassica oleracea (Broccoli) acting as antimicrobial agents against human pathogenic bacteria and fungi

    Science.gov (United States)

    Piruthiviraj, Prakash; Margret, Anita; Krishnamurthy, Poornima Priyadharsani

    2016-04-01

    Production of antimicrobial agents through the synthesis of gold nanoparticles using green technology has been extensively made consistent by various researchers; yet, this study uses the flower bud's aqueous extracts of Brassica oleracea (Broccoli) as a reducing agent for chloroauric acid (1 mM). After 30 min of incubation, synthesis of gold nanoparticles (AuNps) was observed by a change in extract color from pale yellow to purple color. Synthesis of AuNps was confirmed in UV-visible spectroscopy at the range of approximately 560 nm. The SEM analysis showed the average nanoparticles size of 12-22 nm. The antimicrobial activity of AuNps was analyzed by subjecting it to human pathogenic bacteria (Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumonia) and fungi (Aspergillus flavus, Aspergillus niger and Candida albicans) using disc diffusion method. The broccoli-synthesized AuNps showed the efficient antibacterial and antifungal activity of above-mentioned microbes. It was confirmed that AuNps have the best antimicrobial agent compared to the standard antibiotics (Gentamicin and Fluconazole). When the concentrations of AuNps were increased (10, 25, and 50 µg/ml), the sensitivity zone also increased for all the tested microbes. The synthesized AuNps are capable of rendering high antimicrobial efficacy and, hence, have a great potential in the preparation of drugs used against major bacterial and fungal diseases in humans.

  7. A new green chemistry method based on plant extracts to synthesize gold nanoparticles

    Science.gov (United States)

    Montes Castillo, Milka Odemariz

    Extraordinary chemical and physical properties exhibited by nanomaterials, as compared to their bulk counterparts, have made the area of nanotechnology a growing realm in the past three decades. It is the nanoscale size (from 1 to 100 nm) and the morphologies of nanomaterials that provide several properties and applications not possible for the same material in the bulk. Magnetic and optical properties, as well as surface reactivity are highly dependent on the size and morphology of the nanomaterial. Diverse nanomaterials are being widely used in molecular diagnostics as well as in medicine, electronic and optical devices. Among the most studied nanomaterials, gold nanoparticles are of special interest due to their multifunctional capabilities. For instance, spherical gold nanoparticles measuring 15-20 nm in diameter have been studied due to their insulin binding properties. Also, thiol functionalized gold nanoparticles between 5 and 30 nm are used in the detection of DNA. Thus, harnessing the shape and size of gold nanoparticles plays an important role in science and technology. The synthesis of gold nanoparticles via the reduction of gold salts, using citrate or other reducing agents, has been widely studied. In recent years, algae, fungi, bacteria, and living plants have been used to reduce trivalent gold (Au3+) to its zero oxidation state (Au 0) forming gold nanoparticles of different sizes and shapes. In addition, plant biomasses have also been studied for their gold-reducing power and nanoparticle formation. Although there is information about the synthesis of the gold nanoparticles by biologically based materials; to our knowledge, the study of the use of alfalfa extracts has not been reported. This innovation represents a significant improvement; that is an environmentally friendly method that does not use toxic chemicals. Also, the problem of extracting the formed gold nanoparticles from biomaterials is addressed in this research but still remains to be

  8. Using Glutamic Acid, Phenylalanine and Tryptophan to Synthesize Capped Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Kamyar Khoshnevisan

    2011-01-01

    Full Text Available Introduction: The study and investigation of gold nanoparticles produced by amino acid is one of the interesting and applied issues in nanotechnology. In this study, amino acids were used to reduce gold cations as well as an agent to cap gold nanoparticles. In fact, strong bound of amino groups to amino acid and protein on the gold nanoparticles surface indicate the medical applications of these materials. Methods: In this study, gold nanoparticles were prepared and functionalized by using solution reduction containing gold cations with optimum concentration (0.005 M, and also prepared by using glutamic acid, phenylalanine and tryptophan with optimum concentration (0.025 M. Results: The investigation of optimum condition for gold solution and amino acids and also determination of gold nanoparticles were done by UV-Vis. The nanoparticles size were reported 5-20, 10-20 and 20-30 nm respectively by transmission electron microscopy and dynamic light scattering techniques, which is appropriate for biological activities. Conclusion: The comparison of the data from experimental and quantum calculations demonstrated that amino acids have strong band when they are conjugated by anion state. Free carboxylic groups of capped gold nanoparticles with glutamic acid are one of the suitable and capable beads for binding to biological agents.

  9. Synthesis, characterization and biocompatibility of ``green'' synthesized silver nanoparticles using tea polyphenols

    Science.gov (United States)

    Moulton, Michael C.; Braydich-Stolle, Laura K.; NadagoudaPresent Address: Pegasus Technical Services, 46 E. Hollister Street, Cincinnati, 45219, Ohio, Usa., Mallikarjuna N.; Kunzelman, Samantha; Hussain, Saber M.; Varma, Rajender S.

    2010-05-01

    Since ancient times, people have taken advantage of the antimicrobial effects of colloidal silver particles. Aside from the medical prospects, silver nanoparticles are found in a wide range of commercially available consumer products ranging from cosmetics to household cleansers. Current synthetic methods for creating silver nanoparticles typically call for potentially hazardous chemicals, extreme heat, and produce environmentally dangerous byproducts. Therefore, it is essential that novel ``green'' synthesis of nanoparticles becomes a reality, and it is imperative to fully analyze the potential toxic effects of these nanoparticles. In this study, we have shown that by reducing silver nitrate in solutions of tea extract or epicatechin of varying concentrations, spherical silver nanoparticles were formed that had controllable size distributions depending on the concentration of tea extract or epicatechin in the samples. Our ultra-resolution microscopy demonstrated that the nanoparticles were in fact interacting with the keratinocytes. Furthermore, evaluation of mitochondrial function (MTS) to assess cell viability and membrane integrity (LDH) in human keratinocytes showed that the silver nanoparticles were nontoxic. These results demonstrated that these nanoparicles are potentially biocompatible and warrant further evaluation in other biological systems.

  10. Synthesis, characterization and biocompatibility of "green" synthesized silver nanoparticles using tea polyphenols.

    Science.gov (United States)

    Moulton, Michael C; Braydich-Stolle, Laura K; Nadagouda, Mallikarjuna N; Kunzelman, Samantha; Hussain, Saber M; Varma, Rajender S

    2010-05-01

    Since ancient times, people have taken advantage of the antimicrobial effects of colloidal silver particles. Aside from the medical prospects, silver nanoparticles are found in a wide range of commercially available consumer products ranging from cosmetics to household cleansers. Current synthetic methods for creating silver nanoparticles typically call for potentially hazardous chemicals, extreme heat, and produce environmentally dangerous byproducts. Therefore, it is essential that novel "green" synthesis of nanoparticles becomes a reality, and it is imperative to fully analyze the potential toxic effects of these nanoparticles. In this study, we have shown that by reducing silver nitrate in solutions of tea extract or epicatechin of varying concentrations, spherical silver nanoparticles were formed that had controllable size distributions depending on the concentration of tea extract or epicatechin in the samples. Our ultra-resolution microscopy demonstrated that the nanoparticles were in fact interacting with the keratinocytes. Furthermore, evaluation of mitochondrial function (MTS) to assess cell viability and membrane integrity (LDH) in human keratinocytes showed that the silver nanoparticles were nontoxic. These results demonstrated that these nanoparicles are potentially biocompatible and warrant further evaluation in other biological systems. PMID:20648322

  11. Structural, morphological and gas sensing study of zinc doped tin oxide nanoparticles synthesized via hydrothermal technique

    Science.gov (United States)

    Singh, Davender; Kundu, Virender Singh; Maan, A. S.

    2016-07-01

    The pure and Zn-doped SnO2 nanoparticles were prepared successfully by hydrothermal route on large scale having different doping concentration of zinc from 0 to 0.20%. The calcined nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) for structural and morphological studies. XRD analyses reveal that the nanoparticles of these doping concentrations are polycrystalline in nature and existed as tetragonal rutile structure, SEM study of images confirms the existence of very small, homogeneously distributed, and spherical nanoparticles. The particles size of the nanoparticles was calculated by Scherrer formula and was found in the range of 9-21 nm. The presence of dopant (i.e. zinc) and formation of Sn-O phase and hydrous nature of Zn-doped SnO2 nanoparticles are confirmed by EDX and FTIR study. The gas sensing properties of pure and Zn-doped SnO2 nanoparticles were investigated for various concentrations of methanol, ethanol and acetone at different operating temperatures and it has been found that with doping concentration of zinc (x = 0.20%) shows the maximum response 78% to methanol, 65% to ethanol and 62% to acetone respectively at different operating temperature within the measurement limit for a concentration of 100 ppm of each gases.

  12. Novel morphology of needle-Like nanoparticles of Na2Mo2O7 synthesized by using Ultrasonic spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Ivana Lj. Validžić

    2013-02-01

    Full Text Available Low-temperature method for the synthesis of novel morphology of needle-like nanoparticles of disodium dimolybdate (Na2Mo2O7 in the process of ultrasonic spray pyrolysis (USP using aqueous solutions of thermodynamically stable molybdenum (VI oxide clusters as precursor is described. Needle-like Na2Mo2O7 particles were obtained and collected in toluene, while centrifugation was employed to isolate solid material from solution. The scanning electron microscopy (SEM confirmed that the morphology of the synthesized Na2Mo2O7 particles is needle-like collected into bundles. The X-ray Powder Diffraction (XRPD analysis revealed appearance of orthorhombic Na2Mo2O7, synthesized at 300 °C. By comparing the XRPD pattern of the synthesized needle-like Na2Mo2O7 powder obtained in the process of USP with the XRPD pattern simulated for randomly-distributed crystallites by planes, the most prefered growth plane of needle-like nanoparticles were found.

  13. Novel Morphology of Needle-Like Nanoparticles of Na2Mo2O7 Synthesized by Using Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Ivana Lj. Validžić

    2012-01-01

    Full Text Available Low-temperature method for the synthesis of novel morphology of needle-like nanoparticles of disodium dimolybdate (Na2Mo2O7 in the process of ultrasonic spray pyrolysis (USP using aqueous solutions of thermodynamically stable molybdenum (VI oxide clusters as precursor is described. Needle-like Na2Mo2O7 particles were obtained and collected in toluene, while centrifugation was employed to isolate solid material from solution. The scanning electron microscopy (SEM confirmed that the morphology of the synthesized Na2Mo2O7 particles is needle-like collected into bundles. The X-ray Powder Diffraction (XRPD analysis revealed appearance of orthorhombic Na2Mo2O7, synthesized at 300 °C. By comparing the XRPD pattern of the synthesized needle-like Na2Mo2O7 powder obtained in the process of USP with the XRPD pattern simulated for randomly-distributed crystallites by planes, the most prefered growth plane of needle-like nanoparticles were found.

  14. Study of photocatalytic activities of Bi{sub 2}WO{sub 6} nanoparticles synthesized by fast microwave-assisted method

    Energy Technology Data Exchange (ETDEWEB)

    Phu, Nguyen Dang [Faculty of Physics, Hanoi National University of Education, 136 Xuanthuy, Cau Giay, Hanoi (Viet Nam); Hoang, Luc Huy, E-mail: hoanglhsp@hnue.edu.vn [Faculty of Physics, Hanoi National University of Education, 136 Xuanthuy, Cau Giay, Hanoi (Viet Nam); Chen, Xiang-Bai, E-mail: xchen@wit.edu.cn [School of Science and Laboratory of Optical Information Technology, Wuhan Institute of Technology, Wuhan 430205 (China); Kong, Meng-Hong [School of Science and Laboratory of Optical Information Technology, Wuhan Institute of Technology, Wuhan 430205 (China); Wen, Hua-Chiang; Chou, Wu Ching [Department of Electrophysics, National Chiao Tung University, Hsin-Chu 30010, Taiwan (China)

    2015-10-25

    We present a study of photocatalytic activities of Bi{sub 2}WO{sub 6} nanoparticles synthesized by fast microwave-assisted method. The photocatalytic activities of the nanoparticles were evaluated by the decolorization of methylene-blue under visible-light-irradiation. Our results show that the surface area of Bi{sub 2}WO{sub 6} nanoparticles plays a major role for improving photocatalytic activity, while visible-light absorption has only a weak effect on photocatalytic activity. This suggests efficient transportation of photo-generated electrons and holes to the oxidation active sites on the surface of nanoparticles, indicating Bi{sub 2}WO{sub 6} nanoparticles synthesized by fast microwave-assisted method are promising for achieving high photocatalytic activity under visible-light-irradiation. - Highlights: • The Bi{sub 2}WO{sub 6} nanoparticles were synthesized via fast microwave-assisted method. • The obtained Bi{sub 2}WO{sub 6} nanoparticles exhibited visible-light absorbance. • The surface area of Bi{sub 2}WO{sub 6} nanoparticles plays major role for improving photocatalytic activity. • The Bi{sub 2}WO{sub 6} nanoparticles are promising for achieving high photocatalytic activity under visible-light-irradiation.

  15. Assembly and electroanalytical performance of Prussian blue/polypyrrole composite nanoparticles synthesized by the reverse micelle method

    Energy Technology Data Exchange (ETDEWEB)

    Miao Yuqing; Liu Jiwei, E-mail: biosensors@zjnu.c [Laboratory of Biocatalysis and Biosensor, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China)

    2009-04-15

    We report on the characterization, assembly and electroanalytical performance of Prussian blue/polypyrrole (PBPPy) composite nanoparticles synthesized by the reverse micelle method. Scanning electron microscopy suggests the formation of nanosized PBPPy particles with diameters between 40 and 50 nm. Optical absorption confirms that the particles are composed of Prussian blue (PB) and polypyrrole. PB and PBPPy nanoparticles were anchored onto the surface of cysteine-modified Au electrodes. Cyclic voltammetry experiments show that PB- or PBPPy-modified electrodes exhibit intrinsic electrochemical properties and a high electrocatalytic activity towards H{sub 2}O{sub 2}. PBPPy-modified electrodes exhibit a higher sensitivity to H{sub 2}O{sub 2} than PB-modified electrodes. A linear calibration curve in the concentration range 0.99 {mu}M-8.26 mM H{sub 2}O{sub 2} is constructed with a detection limit of 0.23 {mu}M at a signal-to-noise ratio of 3. Excellent stability is observed for PBPPy-composite-nanoparticle-modified electrodes even in a pH 6 phosphate buffer solution with a high H{sub 2}O{sub 2} concentration (0.99 mM). Glutaraldehyde and Nafion were also employed to immobilize glucose oxidase for the development of PBPPy-based biosensors. The results show that PBPPy composite nanoparticles can be used to develop oxidase-based biosensors.

  16. Influence of the Polyvinyl Pyrrolidone Concentration on Particle Size and Dispersion of ZnS Nanoparticles Synthesized by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Nayereh Soltani

    2012-09-01

    Full Text Available Zinc sulfide semiconductor nanoparticles were synthesized in an aqueous solution of polyvinyl pyrrolidone via a simple microwave irradiation method. The effect of the polymer concentration and the type of sulfur source on the particle size and dispersion of the final ZnS nanoparticle product was carefully examined. Microwave heating generally occurs by two main mechanisms: dipolar polarization of water and ionic conduction of precursors. The introduction of the polymer affects the heating rate by restriction of the rotational motion of dipole molecules and immobilization of ions. Consequently, our results show that the presence of the polymer strongly affects the nucleation and growth rates of the ZnS nanoparticles and therefore determines the average particle size and the dispersion. Moreover, we found that PVP adsorbed on the surface of the ZnS nanoparticles by interaction of the C–N and C=O with the nanoparticle’s surface, thereby affording protection from agglomeration by steric hindrance. Generally, with increasing PVP concentration, mono-dispersed colloidal solutions were obtained and at the optimal PVP concentration (5%, sufficiently small size and narrow size distributions were obtained from both sodium sulfide and thioacetamide sulfur sources. Finally, the sulfur source directly influences the reaction mechanism and the final particle morphology, as well as the average size.

  17. Combined structural, electrical, magnetic and optical characterization of bismuth ferrite nanoparticles synthesized by auto-combustion route

    Directory of Open Access Journals (Sweden)

    Sanjay Godara

    2014-12-01

    Full Text Available Phase-pure multiferroic bismuth ferrite (BFO nanoparticles were synthesized by energy efficient, simple and low temperature sol–gel followed by auto-combustion route. Highly crystalline and well-shaped BFO nanoparticles of size about 50 nm were observed in TEM. Thermal analysis was used to optimize the calcination temperature as 500 °C. An endothermic peak at 834 °C has been detected in the DTA curve, representing the Curie temperature. The dielectric anomaly around Neel temperature (TN was observed signifying the magnetoelectric coupling. The BFO nanoparticles were found to be highly resistive (ρ ∼ 3 × 109 Ω-cm and had very low leakage current of the order of μA/cm2, which resulted from phase purity. A significantly enhanced weak ferromagnetism was observed due to smaller particles size and remnant magnetization and coercive field were 0.067 emu/g and 185 Oe, respectively. P–E loop confirmed the ferroelectric behavior of BFO nanoparticles. The direct band gap energy was calculated to be 2.2 eV from UV–vis studies.

  18. A facile method to synthesize polypyrrole nanoparticles in the presence of natural organic phosphate

    International Nuclear Information System (INIS)

    The conductive polymers with unique nanostructures have attracted intense interest due to their potential application. Here the well-defined polypyrrole nanoparticles were facile fabricated via the facile chemical oxidative polymerization of pyrrole with high feeding ratio of phytic acid. Phytic acid is a renewable resource and a natural carbohydrate compound with a vast number of phosphate groups from plant which was used as the template and dopant for the nanostructured conductive polymer for the first time. The samples exhibit the well-defined nanoparticles observed by scanning electron microscope (SEM) and atomic force microscope (AFM). The PPy nanoparticles were achieved and outstanding electrical conductivity as high as 5263 S m−1 was obtained with the feeding mass ratio of phytic acid: pyrrole=3:7. Furthermore, the polypyrrole nanoparticles were characterized with Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and electrical conductivity techniques

  19. A facile method to synthesize polypyrrole nanoparticles in the presence of natural organic phosphate

    Science.gov (United States)

    Yang, Chao; Mo, Haodao; Zang, Limin; Qiu, Jianhui; Sakai, Eiichi; Wu, Xueli

    2014-09-01

    The conductive polymers with unique nanostructures have attracted intense interest due to their potential application. Here the well-defined polypyrrole nanoparticles were facile fabricated via the facile chemical oxidative polymerization of pyrrole with high feeding ratio of phytic acid. Phytic acid is a renewable resource and a natural carbohydrate compound with a vast number of phosphate groups from plant which was used as the template and dopant for the nanostructured conductive polymer for the first time. The samples exhibit the well-defined nanoparticles observed by scanning electron microscope (SEM) and atomic force microscope (AFM). The PPy nanoparticles were achieved and outstanding electrical conductivity as high as 5263 S m-1 was obtained with the feeding mass ratio of phytic acid: pyrrole=3:7. Furthermore, the polypyrrole nanoparticles were characterized with Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and electrical conductivity techniques.

  20. A facile method to synthesize polypyrrole nanoparticles in the presence of natural organic phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chao; Mo, Haodao [State Key Laboratory Breeding Base of Nonferrous Metals and Specific Materials Processing, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004 (China); Zang, Limin, E-mail: D14S004@akita-pu.ac.jp [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Yurihonjo City, Akita 015-0055 (Japan); Qiu, Jianhui; Sakai, Eiichi; Wu, Xueli [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Yurihonjo City, Akita 015-0055 (Japan)

    2014-09-15

    The conductive polymers with unique nanostructures have attracted intense interest due to their potential application. Here the well-defined polypyrrole nanoparticles were facile fabricated via the facile chemical oxidative polymerization of pyrrole with high feeding ratio of phytic acid. Phytic acid is a renewable resource and a natural carbohydrate compound with a vast number of phosphate groups from plant which was used as the template and dopant for the nanostructured conductive polymer for the first time. The samples exhibit the well-defined nanoparticles observed by scanning electron microscope (SEM) and atomic force microscope (AFM). The PPy nanoparticles were achieved and outstanding electrical conductivity as high as 5263 S m{sup −1} was obtained with the feeding mass ratio of phytic acid: pyrrole=3:7. Furthermore, the polypyrrole nanoparticles were characterized with Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and electrical conductivity techniques.

  1. Synthesis of Fe Nanoparticles Functionalized with Oleic Acid Synthesized by Inert Gas Condensation

    Directory of Open Access Journals (Sweden)

    L. G. Silva

    2014-01-01

    Full Text Available In this work, we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs in situ functionalized with oleic acid. The nanoparticles were self-assembled by inert gas condensation (IGC technique by using magnetron-sputtering process. Structural characterization of Fe-NPs was performed by transmission electron microscopy (TEM. Particle size control was carried out through the following parameters: (i condensation zone length, (ii magnetron power, and (iii gas flow (Ar and He. Typically the nanoparticles generated by IGC showed diameters which ranged from ~0.7 to 20 nm. Mass spectroscopy of Fe-NPs in the deposition system allowed the study of in situ nanoparticle formation, through a quadrupole mass filter (QMF that one can use together with a mass filter. When the deposition system works without quadrupole mass filter, the particle diameter distribution is around +/−20%. When the quadrupole is in line, then the distribution can be reduced to around +/−2%.

  2. Nanoparticles from Cu-Zn-Al shape memory alloys physically synthesized by ion milling deposition

    Energy Technology Data Exchange (ETDEWEB)

    Pavon, Luis Alberto Lopez [Universidad Autonoma de Nuevo Leon (UANL), Nuevo Leon (Mexico); Cuellara, Enrique Lopez; Castro, Alejandro Torres; Cruza, Azael Martinez de la [Universidad Autonoma de Nuevo Leon (CIIDIT/UANL), Nuevo Leon (Mexico). Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia; Ballesteros, Carmen [Universidad Carlos III de Madrid, Madrid (Spain). Departamento de Fisica; Araujo, Carlos Jose de [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia Mecanica

    2012-05-15

    In this research, an ion milling equipment was used to elaborate nanoparticles from Cu-Zn-Al alloys with shape memory effect. Two different compositions were used, target A: 75.22Cu-17.12Zn-7.66Al at % with an Ms of -9 deg C and target B: 76.18Cu-15.84Zn-7.98Al with an Ms of 20 degree C. Nanoparticles were characterized by High Resolution Transmission Electron Microscopy, Electron Diffraction and Energy Dispersive X-ray Spectroscopy. The obtained nanoparticles showed a small dispersion, with a size range of 3.2-3.5 nm. Their crystal structure is in good agreement with the bulk martensitic structure of the targets. In this sense, results on morphology, composition and crystal structure have indicated that it is possible to produce nanoparticles of CuZnAl shape memory alloys with martensitic structure in a single process using Ion Milling. (author)

  3. Microscopic evolution of dielectric nanoparticles at different calcination temperatures synthesized via sol-gel auto-combustion

    International Nuclear Information System (INIS)

    Dielectric nano powder synthesis is carried by a simple and fast sol-gel auto-combustion method. The transformation of crystalline phases of as-synthesized nano powders is investigated through the detailed transmission electron microscopy (TEM), revealed the crystallographic alterations and morphological information even at lattice scale. From specific area electron diffraction (SAED) pattern, has specified the d-spacing and corresponding planes supported by the observed lattice fringes. The morphological characterization of nanoparticles is performed through field-emission scanning electron microscopy (FESEM), exhibiting the increment in particle size due to agglomeration with the increase in annealing temperature. Furthermore, EDX pattern has been used to verify the formation of nanoparticles by revealing the presence of required elements

  4. Microscopic evolution of dielectric nanoparticles at different calcination temperatures synthesized via sol-gel auto-combustion

    Energy Technology Data Exchange (ETDEWEB)

    Adil, Muhammad, E-mail: muhammadadil86@hotmail.com; Zaid, Hasnah Mohd, E-mail: hasnamz@petronas.com.my; Chuan, Lee Kean, E-mail: lee.kc@petronas.com.my; Latiff, Noor Rasyada Ahmad, E-mail: syasya.latiff@gmail.com [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Alta’ee, Ali F., E-mail: ali-mangi@petronas.com.my [Geoscience and Petroleum Engineering Department, Universiti Teknologi PETRONAS Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    Dielectric nano powder synthesis is carried by a simple and fast sol-gel auto-combustion method. The transformation of crystalline phases of as-synthesized nano powders is investigated through the detailed transmission electron microscopy (TEM), revealed the crystallographic alterations and morphological information even at lattice scale. From specific area electron diffraction (SAED) pattern, has specified the d-spacing and corresponding planes supported by the observed lattice fringes. The morphological characterization of nanoparticles is performed through field-emission scanning electron microscopy (FESEM), exhibiting the increment in particle size due to agglomeration with the increase in annealing temperature. Furthermore, EDX pattern has been used to verify the formation of nanoparticles by revealing the presence of required elements.

  5. Optimized Packing Density of Large CZTS Nanoparticles Synthesized by Hot-injection for Thin Film Solar Cells

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    to image the faceted/hexagonal nanoparticles and determine their individual composition. Densification of the film will also improve the film-quality. The optimal packing density will be calculated, and size-selective methods can be carried out in order to try to isolate the desired particle sizes. Films......, but to maintain good control of the nanocrystal formation during the synthesis, it is necessary to have organic ligands on the surface of the particles. These ligands are often long alkyl chains that potentially limit the quality of the film and degrade its electronic properties. For nanocrystal solution...... the organic ligands by an antimony salt; however the efficiency is 1.4% for a cell annealed in Se-atmosphere. In our work, we try to limit the carbon amount in the film by synthesizing larger nanoparticles. The bigger the particles are the smaller surface-to-volume ratio they have, which might decrease...

  6. Optical, magnetic and structural characterization of Zn1−CoO nanoparticles synthesized by solvothermal method

    Indian Academy of Sciences (India)

    Tokeer Ahmad; Sarvari Khatoon; Kelsey Coolahan

    2013-11-01

    Nanoparticles of Co-doped ZnO with 3.8, 7.2 and 11.5 wt% were synthesized by solvothermal method through oxalate precursor route. X-ray diffraction studies showed the formation of hexagonal ZnO structure for = 0.038, however, secondary phase of Co3O4 arises on increasing the Co content up to 11.5%. Transmission electron microscopic studies showed that particles are in the nano-metric regime and the grain size decreases on increasing the Co concentration. Optical reflectance measurements showed an energy bandgap, which decreases on increasing Co concentration. Specific surface area of these nanoparticles was found to be very high and comes out to be 97.6, 112.1 and 603.8 m2g-1, respectively. All the solid solutions showed paramagnetism with weak antiferromagnetic interactions. It is seen that the antiferromagnetic interaction increases on increasing Co concentration.

  7. Surface-Enhanced Infrared Absorption of o-Nitroaniline on Nickel Nanoparticles Synthesized by Electrochemical Deposition

    OpenAIRE

    Yufang Niu; Jie Yao; Keyu Wang

    2014-01-01

    Nickel nanoparticles were electrochemically deposited on indium-tin oxide (ITO) coated glass plate in a modified Watt’s electrolyte. The surface-enhanced infrared absorption (SEIRA) effect of the nanoparticles was evaluated by attenuated total reflection spectroscopy (ATR-FTIR) using o-nitroaniline as a probe molecule. Electrodeposition parameters such as deposition time, pH value, and the type of surfactants were investigated. The morphology and the microstructure of the deposits were charac...

  8. Structural and Morphological Properties of Cr2O3 Nanoparticles Synthesized By Novel Solvent Free Method

    OpenAIRE

    Meenambika .R; Ramalingom .S

    2014-01-01

    Nanoparticles of chromium oxide (Cr2O3) are widely used in many fields serving as catalysts, wear resistance materials, and advanced colorants. For the first time, we have reported the solvent free synthesis of Cr2O3 nanoparticles via microwave irradiation followed by calcinations at 200, 400, 600 and 800°C for 1h. The influence of calcination temperature on the particle size, microstructure and morphology was examined by X-ray diffraction, Scanning Electron Microscope (SEM) and Transmission ...

  9. Evaluation of antibacterial activities of silver nanoparticles green-synthesized using pineapple leaf (Ananas comosus).

    Science.gov (United States)

    Emeka, Elemike Elias; Ojiefoh, Oseghale Charles; Aleruchi, Chuku; Hassan, Labulo Ayomide; Christiana, Owoseni Mojisola; Rebecca, Mfon; Dare, Enock Olugbenga; Temitope, Adesuji Elijah

    2014-02-01

    Pineapple leaf was used in this study for the synthesis of silver nanoparticles based on the search for sustainable synthetic means. Indeed, this offered an economical and sustainable synthetic route relative to expensive and toxic chemical methods. The leaf extract was used and the corresponding nanoparticles obtained were subjected to UV-vis analysis at different times. The UV-vis was used to monitor the silver nanoparticle formation through sampling at time intervals. The formation of silver nanoparticles was apparently displayed within 2 min with evidence of surface plasmon bands (SPB) between 440 and 460 nm. The crystals was equally characterized using FTIR, X-ray diffraction methods and TEM. The different results obtained suggested the appearance of silver nanoparticles (SNPs) as determined by the process parameters with a particle size of 12.4 nm. The sample was further screened against Staphylococcus aureus, Streptococcus pneumoniae, Proteus mirabilis and Escherichia coli using Gentamicin as control. From the results, there is evidence of inhibition towards bacteria growth. It can now be inferred from the studies that biosynthesis of nanoparticles could be a gateway to our numerous health issues. PMID:24268599

  10. Possible size control and emission characteristics of Eu3+-doped Y2O3 nanoparticles synthesized by surfactant-assembly

    Science.gov (United States)

    Akita, Yukihiko; Harada, Takashi; Sasai, Ryo; Tomita, Koji; Nishiyama, Katsura

    2016-08-01

    Yttrium oxide nanoparticles doped with 2.0 wt% Eu (Eu@Y2O3) were synthesized via the surfactant-assembly method. The average diameter of Eu@Y2O3 (dav) depends on the alkyl chain number (N) of the sodium alkyl sulfates employed as surfactants. Using surfactants with N = 8, 10, and 12, Eu@Y2O3 with dav = 35, 200, and 500 nm, respectively were obtained. Such changes in dav are ascribed to the difference in the micelle aggregation numbers, supporting the use of rare-earth ions in the assembly. The Eu@Y2O3 particles synthesized presently emitted through Eu3+ transitions under UV excitation of Y2O3, making them applicable to nanoemitters.

  11. Biosynthesis, characterization and antimicrobial studies of green synthesized silver nanoparticles from fruit extract of Syzygium alternifolium (Wt.) Walp. an endemic, endangered medicinal tree taxon

    Science.gov (United States)

    Yugandhar, P.; Savithramma, N.

    2016-02-01

    In nanotechnology, the plant mediated synthesis of nanoparticles has terrific application in biomedicine due to its novel properties and its eco-friendly nature. The present study deals with the biosynthesis of stable silver nanoparticles (SNPs) from aqueous fruit extract of S. alternifolium an endemic medicinal plant to Eastern Ghats. The synthesized nanoparticles are characterized by UV-VIS spectroscopy, FTIR, XRD, AFM, SEM with EDAX and TEM. Colour change from brown to grey indicates the formation of nanoparticles and UV-VIS surface plasmon resonance spectroscopy observed at 442 nm further confirms the synthesized nanoparticles are SNPs. FTIR studies reveal that the phenols and primary amines of proteins are main responsible for reduction, stabilization and capping agents towards these SNPs. The XRD data show crystalline nature of nanoparticles and EDAX measurements reveal the (12.74 %) percentage presence of Ag metal. AFM, SEM and TEM microscopic analyses revealed that the size of synthesized SNPs ranging from 5 to 68 nm has spherical shape and they are in polydispersed condition. Further, the antimicrobial studies of synthesized SNPs show high toxicity towards different bacterial and fungal isolates. This is the first report on fruit mediated synthesis of silver nanoparticles from S. alternifolium.

  12. Characterization of intracellular palladium nanoparticles synthesized by Desulfovibrio desulfuricans and Bacillus benzeovorans

    Energy Technology Data Exchange (ETDEWEB)

    Omajali, Jacob B., E-mail: JBO037@bham.ac.uk, E-mail: jbomajali@gmail.com; Mikheenko, Iryna P. [University of Birmingham, Unit of Functional Bionanomaterials, School of Biosciences, Institute of Microbiology and Infection (United Kingdom); Merroun, Mohamed L. [University of Granada, Department of Microbiology, Faculty of Sciences (Spain); Wood, Joseph [University of Birmingham, School of Chemical Engineering (United Kingdom); Macaskie, Lynne E. [University of Birmingham, Unit of Functional Bionanomaterials, School of Biosciences, Institute of Microbiology and Infection (United Kingdom)

    2015-06-15

    Early studies have focused on the synthesis of palladium nanoparticles within the periplasmic layer or on the outer membrane of Desulfovibrio desulfuricans and on the S-layer protein of Bacillus sphaericus. However, it has remained unclear whether the synthesis of palladium nanoparticles also takes place in the bacterial cell cytoplasm. This study reports the use of high-resolution scanning transmission electron microscopy with a high-angle annular dark field detector and energy dispersive X-ray spectrometry attachment to investigate the intracellular synthesis of palladium nanoparticles (Pd NPs). We show the intracellular synthesis of Pd NPs within cells of two anaerobic strains of D. desulfuricans and an aerobic strain of B. benzeovorans using hydrogen and formate as electron donors. The Pd nanoparticles were small and largely monodispersed, between 0.2 and 8 nm, occasionally from 9 to 12 nm with occasional larger nanoparticles. With D. desulfuricans NCIMB 8307 (but not D. desulfuricans NCIMB 8326) and with B. benzeovorans NCIMB 12555, the NPs were larger when made at the expense of formate, co-localizing with phosphate in the latter, and were crystalline, but were amorphous when made with H{sub 2,} with no phosphorus association. The intracellular Pd nanoparticles were mainly icosahedrons with surfaces comprising {111} facets and about 5 % distortion when compared with that of bulk palladium. The particles were more concentrated in the cell cytoplasm than the cell wall, outer membrane, or periplasm. We provide new evidence for synthesis of palladium nanoparticles within the cytoplasm of bacteria, which were confirmed to maintain cellular integrity during this synthesis.

  13. Induction of Apoptosis by Green Synthesized Gold Nanoparticles Through Activation of Caspase-3 and 9 in Human Cervical Cancer Cells

    Science.gov (United States)

    Baharara, Javad; Ramezani, Tayebe; Divsalar, Adeleh; Mousavi, Marzieh; Seyedarabi, Arefeh

    2016-01-01

    Background: Gold Nanoparticles (GNPs) are used in imaging and molecular diagnostic applications. As the development of a novel approach in the green synthesis of metal nanoparticles is of great importance and a necessity, a simple and safe method for the synthesis of GNPs using plant extracts of Zataria multiflora leaves was applied in this study and the results on GNPs’ anticancer activity against HeLa cells were reported. Methods: The GNPs were characterized by UV-visible spectroscopy, FTIR, TEM, DLS and Zeta-potential measurements. In addition, the cellular up-take of nanoparticles was investigated using Dark Field Microscopy (DFM). Induction of apoptosis by high dose of GNPs in HeLa cells was assessed by MTT assay, Acridin orange, DAPI staining, Annexin V/PI double-labeling flow cytometry and caspase activity assay. Results: UV-visible spectroscopy results showed a surface plasmon resonance band for GNPs at 530 nm. FTIR results demonstrated an interaction between plant extract and nanoparticles. TEM images revealed different shapes for GNPs and DLS results indicated that the GNPs range in size from 10 to 42 nm. The Zeta potential values of the synthesized GNPs were between 30 to 50 Mev, indicating the formation of stable particles. As evidenced by MTT assay, GNPs inhibit proliferation of HeLa cells in dose-dependent GNPs and cytotoxicity of GNPs in Bone Marrow Mesenchymal Stem Cell (BMSCs) was lower than cancerous cells. At nontoxic concentrations, the cellular up-take of the nanoparticles took place. Acridin orange and DAPI staining showed morphological changes in the cell’s nucleus due to apoptosis. Finally, caspase activity assay demonstrated HeLa cell’s apoptosis through caspase activation. Conclusion: The results showed that GNPs have the ability to induce apoptosis in HeLa cells. PMID:27141266

  14. Magnetic properties of sonochemically synthesized CoCr2O4 nanoparticles

    Science.gov (United States)

    Dutta, Dimple P.; Manjanna, J.; Tyagi, A. K.

    2009-08-01

    Cobalt chromite (CoCr2O4) is a potential multiferroic material. In order to understand the temperature dependent magnetic transitions on particle morphology, here we prepared CoCr2O4 nanoparticles by sonochemical technique. We used powder x-ray diffraction, transmission electron microscopy, selected area electron diffraction, superconducting quantum interference device magnetometer, and ac susceptibility measurement techniques for characterization. The low-temperature magnetic behavior of CoCr2O4 nanoparticles have been investigated in more detail. While the bulk CoCr2O4 exhibits two magnetic transitions viz., Tc≈98 K and Ts≈26 K, the nanoparticles here showed a Tc≈84 K and Ts≈25 K. We tentatively attribute this shift in Tc to finite size effects.

  15. Air-stable Fe@Au nanoparticles synthesized by the microemulsion's methods

    Science.gov (United States)

    Rivas, José; Redondo, Yolanda Piñeiro; Iglesias-Silva, Esther; Vilas-Vilela, J. M.; León, L. M.; López-Quintela, Manuel Arturo

    2013-05-01

    Magnetic particles covered by gold are very important in many biological applications. However, there are not simple methods to produce small (microemulsions, can avoid such problems and is able to produce very stable core-shell Fe@Au nanoparticles. With this procedure, nanoparticles of ˜6 nm with a Fe core of 3 nm can easily be obtained. These Fe@Au nanoparticles, with a saturation magnetization of 1.13 emu/g, are very stable even in air after magnetic separation from the solution, which shows the good covering of the Fe core by the Au shell. In this contribution we will report the key parameters, which have to be taken into account, to prepare such stable Fe@Au dispersions and analyze their optical and magnetic properties, as well as their possible applications as biosensors, targeted magnetic separation, etc.

  16. Supported palladium nanoparticles synthesized by living plants as a catalyst for Suzuki-Miyaura reactions.

    Directory of Open Access Journals (Sweden)

    Helen L Parker

    Full Text Available The metal accumulating ability of plants has previously been used to capture metal contaminants from the environment; however, the full potential of this process is yet to be realized. Herein, the first use of living plants to recover palladium and produce catalytically active palladium nanoparticles is reported. This process eliminates the necessity for nanoparticle extraction from the plant and reduces the number of production steps compared to traditional catalyst palladium on carbon. These heterogeneous plant catalysts have demonstrated high catalytic activity in Suzuki coupling reactions between phenylboronic acid and a range of aryl halides containing iodo-, bromo- and chloro- moieties.

  17. Cymbopogon citratus-synthesized gold nanoparticles boost the predation efficiency of copepod Mesocyclops aspericornis against malaria and dengue mosquitoes.

    Science.gov (United States)

    Murugan, Kadarkarai; Benelli, Giovanni; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Jeyalalitha, Tirupathi; Dinesh, Devakumar; Nicoletti, Marcello; Hwang, Jiang-Shiou; Suresh, Udaiyan; Madhiyazhagan, Pari

    2015-06-01

    Plant-borne compounds can be employed to synthesize mosquitocidal nanoparticles that are effective at low doses. However, how they affect the activity of mosquito predators in the aquatic environment is unknown. In this study, we synthesized gold nanoparticles (AuN) using the leaf extract of Cymbopogon citratus, which acted as a reducing and capping agent. AuN were characterized by a variety of biophysical methods and sorted for size in order to confirm structural integrity. C. citratus extract and biosynthesized AuN were tested against larvae and pupae of the malaria vector Anopheles stephensi and the dengue vector Aedes aegypti. LC₅₀ of C. citratus extract ranged from 219.32 ppm to 471.36 ppm. LC₅₀ of AuN ranged from 18.80 ppm to 41.52 ppm. In laboratory, the predatory efficiency of the cyclopoid crustacean Mesocyclops aspericornis against A. stephensi larvae was 26.8% (larva I) and 17% (larva II), while against A. aegypti was 56% (I) and 35.1% (II). Predation against late-instar larvae was minimal. In AuN-contaminated environment,predation efficiency against A. stephensi was 45.6% (I) and 26.7% (II), while against A. aegypti was 77.3% (I) and 51.6% (II). Overall, low doses of AuN may help to boost the control of Anopheles and Aedes larval populations in copepod-based control programs.

  18. Structural and electrical properties of TiO{sub 2}/ZnO core–shell nanoparticles synthesized by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Vlazan, P.; Ursu, D.H. [National Institute for Research and Development in Electrochemistry and Condensed Matter, Department of Condensed Matter, 1 Plautius Andronescu St., 300224 Timisoara (Romania); Irina-Moisescu, C. [Faculty of Industrial Chemistry and Environmental Engineering, “Politehnica” University of Timisoara, 6 Vasile Parvan Avenue, 300223 Timisoara (Romania); Miron, I., E-mail: mironiasmina@gmail.com [National Institute for Research and Development in Electrochemistry and Condensed Matter, Department of Condensed Matter, 1 Plautius Andronescu St., 300224 Timisoara (Romania); Sfirloaga, P. [National Institute for Research and Development in Electrochemistry and Condensed Matter, Department of Condensed Matter, 1 Plautius Andronescu St., 300224 Timisoara (Romania); Faculty of Physics, West University of Timisoara, 4 Vasile Parvan Avenue, 300223 Timisoara (Romania); Rusu, E. [Institute of Electronic Engineering and Nanotechnologies, “D. Ghiţu” of the Academy of Sciences of Moldova, Academiei str. 3, Chisinau MD-2028, Academiei str. 3, Chisinau MD-2028 (Moldova, Republic of)

    2015-03-15

    TiO{sub 2}/ZnO core–shell nanoparticles were successfully synthesized by hydrothermal method in two stages: first stage is the hydrothermal synthesis of ZnO nanoparticles and second stage the obtained ZnO nanoparticles are encapsulated in TiO{sub 2}. The obtained ZnO, TiO{sub 2} and TiO{sub 2}/ZnO core–shell nanoparticles were investigated by means of X-ray diffraction, transmission electron microscopy, Brunauer, Emmett, Teller and resistance measurements. X-ray diffraction analysis revealed the presence of both, TiO{sub 2} and ZnO phases in TiO{sub 2}/ZnO core–shell nanoparticles. According to transmission electron microscopy images, ZnO nanoparticles have hexagonal shapes, TiO{sub 2} nanoparticles have a spherical shape, and TiO{sub 2}/ZnO core–shell nanoparticles present agglomerates and the shape of particles is not well defined. The activation energy of TiO{sub 2}/ZnO core–shell nanoparticles was about 101 meV. - Graphical abstract: Display Omitted - Highlights: • TiO{sub 2}/ZnO core–shell nanoparticles were synthesized by hydrothermal method. • TiO{sub 2}/ZnO core–shell nanoparticles were investigated by means of XRD, TEM and BET. • Electrical properties of TiO{sub 2}/ZnO core–shell nanoparticles were investigated. • The activation energy of TiO{sub 2}/ZnO core–shell nanoparticles was about E{sub a} = 101 meV.

  19. Development and application of nanoparticles synthesized with folic acid-conjugated soy protein

    Science.gov (United States)

    In this study, soy protein isolate (SPI) was conjugated with folic acid (FA) to prepare nanoparticles for target-specific drug delivery. Successful conjugation was evidenced by UV spectrophotometry and primary amino group analysis. An increase in count rate by at least 142% was observed in FA-conjug...

  20. Silver nanoparticles of variable morphology synthesized in aqueous foams as novel templates

    Indian Academy of Sciences (India)

    Saikat Mandal; Sujatha K Arumugam; Renu Pasricha; Murali Sastry

    2005-08-01

    In this paper, we describe the synthesis of silver nanocrystals within aqueous foams as a template. More specifically, we show that aqueous Ag+ ions may be electrostatically complexed with the anionic surfactants aerosol OT (sodium bis-2-ethylhexyl-sulfosuccinate, (AOT) and sodium dodecyl sulphate (SDS)) in a highly stable liquid foam. After drainage of the foam, the silver ions are reduced in situ by introducing sodium borohydride into the foam by capillary flow. This leads to the formation of silver nanoparticles of spherical, tape- and sheet-like morphology in the foam. The structure of the foam is extremely complex and presents reaction sites of different spatial extent. The differences in foam reaction–site geometry are believed to be responsible for the morphology variation in the silver nanoparticles observed. The silver nanoparticles are observed to be extremely stable in solution suggesting that the AOT or SDS molecules stabilize them. This approach appears promising for application in large-scale synthesis of nanoparticles and may be readily extended to other chemical compositions.

  1. Phase composition and morphology of nanoparticles of yttrium orthophosphates synthesized by microwave-hydrothermal treatment: The influence of synthetic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vanetsev, A.S., E-mail: alexander.vanetsev@ut.ee [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Samsonova, E.V. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Gaitko, O.M. [Kurnakov Institute of General and Inorganic Chemistry RAS, Leninskii Prospekt 31, Moscow 119991 (Russian Federation); Keevend, K. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Popov, A.V. [Prokhorov General Physics Institute RAS, Vavilov St. 38, Moscow 119991 (Russian Federation); Mäeorg, U. [Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411 (Estonia); Mändar, H.; Sildos, I. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Orlovskii, Yu.V. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Prokhorov General Physics Institute RAS, Vavilov St. 38, Moscow 119991 (Russian Federation)

    2015-08-05

    Highlights: • We synthesized YPO{sub 4} and YPO{sub 4}⋅0.8H{sub 2}O nanoparticles by microwave-hydrothermal treatment. • We studied “conditions–composition–properties” relations for this synthetic path. • We revealed the mechanism of stabilization of YPO{sub 4}⋅0.8H{sub 2}O phase at high temperatures. - Abstract: Herein we report the study of the influence of synthesis conditions during the microwave-hydrothermal crystallization of freshly precipitated gels on the phase composition and morphology of the rare-earth doped yttrium orthophosphates nanoparticles. We characterize the nanoparticles of YPO{sub 4} and YPO{sub 4}⋅0.8H{sub 2}O using X-ray diffraction analysis, TEM, and FT-IR spectroscopy. Furthermore, we argue that for the given phase the degree of crystallinity and thus the sample morphology depend strongly on the synthesis conditions. We establish that the hexagonal hydrate phase can be obtained by means of microwave-hydrothermal method if one uses phosphate anion excess or adjusts pH of the reaction mixture. Also we show that the metastable hydrate phase is most likely stabilized by hydroxyl groups at elevated temperatures.

  2. Nanostructural Features of Silver Nanoparticles Powder Synthesized through Concurrent Formation of the Nanosized Particles of Both Starch and Silver

    Directory of Open Access Journals (Sweden)

    A. Hebeish

    2013-01-01

    Full Text Available Green innovative strategy was developed to accomplish silver nanoparticles formation of starch-silver nanoparticles (St-AgNPs in the powder form. Thus, St-AgNPs were synthesized through concurrent formation of the nanosized particles of both starch and silver. The alkali dissolved starch acts as reducing agent for silver ions and as stabilizing agent for the formed AgNPs. The chemical reduction process occurred in water bath under high-speed homogenizer. After completion of the reaction, the colloidal solution of AgNPs coated with alkali dissolved starch was cooled and precipitated using ethanol. The powder precipitate was collected by centrifugation, then washed, and dried; St-AgNPs powder was characterized using state-of-the-art facilities including UV-vis spectroscopy, Transmission Electron Microscopy (TEM, particle size analyzer (PS, Polydispersity index (PdI, Zeta potential (ZP, XRD, FT-IR, EDX, and TGA. TEM and XRD indicate that the average size of pure AgNPs does not exceed 20 nm with spherical shape and high concentration of AgNPs (30000 ppm. The results obtained from TGA indicates that the higher thermal stability of starch coated AgNPS than that of starch nanoparticles alone. In addition to the data obtained from EDX which reveals the presence of AgNPs and the data obtained from particle size analyzer and zeta potential determination indicate that the good uniformity and the highly stability of St-AgNPs.

  3. Study on Nanoparticles of ZnSe Synthesized by Chemical Method and Their Characterization

    Directory of Open Access Journals (Sweden)

    M.P. Deshpande

    2011-01-01

    Full Text Available The properties of semiconductor nanoparticles depend mainly on their shape and size due to high surface-to-volume ratio. The II – VI semiconductors have many applications such as, LED, acousto-optical effects and biological sensors. The ZnSe nanoparticles have wide-ranging applications in laser, optical instruments etc. because it has wide band gap and transmittance range, high luminescence efficiency, low absorption coefficient. In recent years, much attention was paid on the preparation methods, performances and applications of ZnSe nanoparticles and thin solid films, and a lot of important accomplishments have been obtained. In the present study ZnSe nanoparticles were successfully prepared by reacting Zn(CH3COO2·2H2O and Na2SeSO3 at 343 K. The size of the crystallite was estimated by X-ray diffraction and TEM, whereas EDAX has confirmed of no foreign impurity inclusion in ZnSe nanoparticles. XRD shows the crystallite size of 5.68 nm and TEM gives a distribution ranging from 20 nm to 71 nm. A SEM image shows that the particles are spherical in a shape. Quantum confinement has resulted in the blue shift compared to bulk ZnSe as observed from the absorption spectra of particles dispersed in DMF. We obtained the photoluminescence spectra on these particles with two different excitation wavelength which shows broad band emission peak at 573 nm. Photoluminescence spectra taken with other excitation wavelength also gives sharp emission peaks at 484 nm, 530 nm, 551 nm and 600 nm.

  4. Characterization and antibacterial properties of stable silver substituted hydroxyapatite nanoparticles synthesized through surfactant assisted microwave process

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Nida [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Abdul Kadir, Mohammed Rafiq, E-mail: rafiq@biomedical.utm.my [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Nik Malek, Nik Ahmad Nazim [Faculty of Bioscience and Medical Engineering (FBME), Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Mahmood, Nasrul Humaimi Bin [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Murali, Malliga Raman; Kamarul, T. [Tissue Engineering Group, NOCERAL, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2013-09-01

    Highlights: • Stable nano sized silver substitute hydroxyapatite is prepared under surfactant assisted microwave process at 600 W power for 7 min. • The nanoparticles are in the size range of 58–72 nm and exert uniform elongated spheroid morphology. • Increase in silver concentration resulted in better dielectric properties. • Good antibacterial activity and silver release. - Abstract: The present study reports a relatively simple method for the synthesis of stable silver substituted hydroxyapatite nanoparticles with controlled morphology and particle size. In order to achieve this, CTAB is included as a surfactant in the microwave refluxing process (600 W for 7 min). The nanoparticles produced with different silver ion concentrations (0.05, 0.1 and 0.2 wt%) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX) and Brunauer–Emmett–Teller (BET) analysis. XRD and FTIR analyses reveal that the Ag-HA nanoparticles were phase pure at 1000 °C. FESEM images showed that the produced nanoparticles are in the size range of 58–72 nm and exert uniform elongated spheroid morphology. The dielectric properties suggest that the increase in dielectric constant (ε′) and dissipation factor (D) values with increasing Ag concentrations. Antibacterial performance of the Ag-HA samples elucidated using disk diffusion technique (DDT) and minimum inhibitory concentration (MIC) demonstrates anti-bacterial activity against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli. This effect was dose dependent and was more pronounced against Gram-negative bacteria than Gram-positive organisms.

  5. Combined efficacy of biologically synthesized silver nanoparticles and different antibiotics against multidrug-resistant bacteria

    Directory of Open Access Journals (Sweden)

    Naqvi SZ

    2013-08-01

    Full Text Available Syed Zeeshan Haider Naqvi, Urooj Kiran, Muhammad Ishtiaq Ali, Asif Jamal, Abdul Hameed, Safia Ahmed, Naeem Ali Microbiology Research Laboratory, Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan Abstract: Biological synthesis of nanoparticles is a growing innovative approach that is relatively cheaper and more environmentally friendly than current physicochemical processes. Among various microorganisms, fungi have been found to be comparatively more efficient in the synthesis of nanomaterials. In this research work, extracellular mycosynthesis of silver nanoparticles (AgNPs was probed by reacting the precursor salt of silver nitrate (AgNO3 with culture filtrate of Aspergillus flavus. Initially, the mycosynthesis was regularly monitored by ultraviolet-visible spectroscopy, which showed AgNP peaks of around 400–470 nm. X-ray diffraction spectra revealed peaks of different intensities with respect to angle of diffractions (2θ corresponding to varying configurations of AgNPs. Transmission electron micrographs further confirmed the formation of AgNPs in size ranging from 5–30 nm. Combined and individual antibacterial activities of the five conventional antibiotics and AgNPs were investigated against eight different multidrug-resistant bacterial species using the Kirby–Bauer disk-diffusion method. The decreasing order of antibacterial activity (zone of inhibition in mm of antibiotics, AgNPs, and their conjugates against bacterial group (average was; ciprofloxacin + AgNPs (23 > imipenem + AgNPs (21 > gentamycin + AgNPs (19 > vancomycin + AgNPs (16 > AgNPs (15 > imipenem (14 > trimethoprim + AgNPs (14 > ciprofloxacin (13 > gentamycin (11 > vancomycin (4 > trimethoprim (0. Overall, the synergistic effect of antibiotics and nanoparticles resulted in a 0.2–7.0 (average, 2.8 fold-area increase in antibacterial activity, which clearly revealed that nanoparticles can be effectively used in

  6. Influence of Reaction Solvent on Crystallinity and Magnetic Properties of MnFe2O4 Nanoparticles Synthesized by Thermal Decomposition

    Directory of Open Access Journals (Sweden)

    Lina Song

    2016-01-01

    Full Text Available This study reports the synthesis of three kinds of manganese-doped magnetic ferrite nanoparticles (MnFe2O4 in benzyl ether, octyl ether, and 1-octadecene by a simple and low cost thermal decomposition method. It was found that benzyl ether results in a dramatic improvement in nanoparticle crystallinity owing to its stronger reducibility compared to octyl ether and 1-octadecene, as demonstrated by X-ray diffraction and TEM measurements. Raman spectroscopy detection also indicated that the reducing solvent of benzyl ether was in favor of forming magnetite-like structure ferrite, while maghemite-like structured ferrite was obtained in octyl ether and 1-octadecene. The saturation magnetization (MS of MnFe2O4 synthesized in benzyl ether was 85 emu/g [Fe], which was 3 and 5 times larger than MnFe2O4 synthesized in octyl ether and 1-octadecene, respectively. The specific absorption rate (SAR of MnFe2O4 nanoparticles synthesized in benzyl ether was 574 W/g, while MnFe2O4 nanoparticles synthesized in octyl ether and 1-octadecene have had much smaller SAR of 76 and 33 W/g, respectively. MnFe2O4 nanoparticles synthesized in benzyl ether also exhibit higher relaxivity (r2=207 mM−1 s−1 than those synthesized in octyl ether and 1-octadecene (r2=65 and 22 mM−1 s−1. It was obvious that MnFe2O4 nanoparticles synthesized in reducing benzyl ether have higher crystallinity and thus higher MS, SAR, and r2 values, which can serve as a better candidate for hyperthermia and magnetic resonance imaging.

  7. Syntheses of Cu2SnS3 and Cu2ZnSnS4 nanoparticles with tunable Zn/Sn ratios under multibubble sonoluminescence conditions.

    Science.gov (United States)

    Park, Jongpil; Song, Miyeon; Jung, Won Mok; Lee, Won Young; Kim, Hanggeun; Kim, Youngkwon; Hwang, Chahwan; Shim, Il-Wun

    2013-08-01

    Cu2ZnSnS4 (CZTS) nanoparticles were synthesized by sonochemical reactions under multibubble sonoluminescence (MBSL) conditions. First, Cu2SnS3 (CTS) nanoparticles were synthesized by the sonochemical method with a 91.3% yield. Second, ZnS was coated on Cu2SnS3 nanoparticles by the same method. Then, they were transformed into CZTS nanoparticles of 90-300 nm diameter by heating them at 450 °C for 1 hour. The ratios between Zn and Sn could be controlled from 0.20 to 1.32 by adjusting the relative concentrations of Cu2SnS3 and ZnCl2. With relatively lower Zn : Sn ratios (0.20-0.41), there was a mixture of CTS and CZTS nanoparticles. The prepared nanoparticles show different band gaps from 1.19 to 1.52 eV depending on the zinc to tin ratio. In this sonochemical method without using any toxic or high temperature solvents, the specific stoichiometric element ratios in CZTS were controllable on demand and their experimental results were always reproducible in separate syntheses. The CZTS nanoparticles were investigated by using X-ray diffraction, a UV-Vis spectrophotometer, a scanning electron microscope, Raman spectroscopy, and a high resolution-transmission electron microscope. PMID:23759949

  8. The Effect of Green Synthesized CuO Nanoparticles on Callogenesis and Regeneration of Oryza sativa L.

    Science.gov (United States)

    Anwaar, Sadaf; Maqbool, Qaisar; Jabeen, Nyla; Nazar, Mudassar; Abbas, Fazal; Nawaz, Bushra; Hussain, Talib; Hussain, Syed Z.

    2016-01-01

    In this study, we have investigated the effect of copper oxide nanoparticles (CuO-NPs) on callogenesis and regeneration of Oryza sativa L (Super Basmati, Basmati 2000, Basmati 370, and Basmati 385). In this regard, CuO-NPs have been bio-synthesized via Azadirachta indica leaf extract. Scanning electron microscope (SEM) analysis depicts average particle size of 40 ± 5 nm with highly homogenous and spherical morphology. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) have been employed to confirm the phase purity of the synthesized NPs. It is found that CuO-NPs exhibit very promising results against callus induction. It is attributed to the fact that green synthesized CuO-NPs at optimum dosage possess very supportive effects on plant growth parameters. In contrast to callogenesis, differential regeneration pattern has been observed against all of the examined O. sativa L. indigenous verities. Overall observation concludes that CuO, being one of the essential plant nutrients, has greatly tailored the nutritive properties at nano-scale. PMID:27630655

  9. The Effect of Green Synthesized CuO Nanoparticles on Callogenesis and Regeneration of Oryza sativa L.

    Science.gov (United States)

    Anwaar, Sadaf; Maqbool, Qaisar; Jabeen, Nyla; Nazar, Mudassar; Abbas, Fazal; Nawaz, Bushra; Hussain, Talib; Hussain, Syed Z.

    2016-01-01

    In this study, we have investigated the effect of copper oxide nanoparticles (CuO-NPs) on callogenesis and regeneration of Oryza sativa L (Super Basmati, Basmati 2000, Basmati 370, and Basmati 385). In this regard, CuO-NPs have been bio-synthesized via Azadirachta indica leaf extract. Scanning electron microscope (SEM) analysis depicts average particle size of 40 ± 5 nm with highly homogenous and spherical morphology. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) have been employed to confirm the phase purity of the synthesized NPs. It is found that CuO-NPs exhibit very promising results against callus induction. It is attributed to the fact that green synthesized CuO-NPs at optimum dosage possess very supportive effects on plant growth parameters. In contrast to callogenesis, differential regeneration pattern has been observed against all of the examined O. sativa L. indigenous verities. Overall observation concludes that CuO, being one of the essential plant nutrients, has greatly tailored the nutritive properties at nano-scale.

  10. Nanoparticles of complex metal oxides synthesized using the reverse-micellar and polymeric precursor routes

    Indian Academy of Sciences (India)

    Ashok K Ganguli; Tokeer Ahmad; Padam R Arya; Pika Jha

    2005-11-01

    Current interest in the properties of materials having grains in the nanometer regime has led to the investigation of the size-dependent properties of various dielectric and magnetic materials. We discuss two chemical methods, namely the reverse-micellar route and the polymeric citrate precursor route used to obtain homogeneous and monophasic nanoparticles of several dielectric oxides like BaTiO3, Ba2TiO4, SrTiO3, PbTiO3, PbZrO3 etc. In addition we also discuss the synthesis of some transition metal (Mn and Cu) oxalate nanorods using the reverse-micellar route. These nanorods on decomposition provide a facile route to the synthesis of transition metal oxide nanoparticles. We discuss the size dependence of the dielectric and magnetic properties in some of the above oxides.

  11. A Novel DNA Nanosensor Based on CdSe/ZnS Quantum Dots and Synthesized Fe3O4 Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Roozbeh Hushiarian

    2014-04-01

    Full Text Available Although nanoparticle-enhanced biosensors have been extensively researched, few studies have systematically characterized the roles of nanoparticles in enhancing biosensor functionality. This paper describes a successful new method in which DNA binds directly to iron oxide nanoparticles for use in an optical biosensor. A wide variety of nanoparticles with different properties have found broad application in biosensors because their small physical size presents unique chemical, physical, and electronic properties that are different from those of bulk materials. Of all nanoparticles, magnetic nanoparticles are proving to be a versatile tool, an excellent case in point being in DNA bioassays, where magnetic nanoparticles are often used for optimization of the hybridization and separation of target DNA. A critical step in the successful construction of a DNA biosensor is the efficient attachment of biomolecules to the surface of magnetic nanoparticles. To date, most methods of synthesizing these nanoparticles have led to the formation of hydrophobic particles that require additional surface modifications. As a result, the surface to volume ratio decreases and nonspecific bindings may occur so that the sensitivity and efficiency of the device deteriorates. A new method of large-scale synthesis of iron oxide (Fe3O4 nanoparticles which results in the magnetite particles being in aqueous phase, was employed in this study. Small modifications were applied to design an optical DNA nanosensor based on sandwich hybridization. Characterization of the synthesized particles was carried out using a variety of techniques and CdSe/ZnS core-shell quantum dots were used as the reporter markers in a spectrofluorophotometer. We showed conclusively that DNA binds to the surface of ironoxide nanoparticles without further surface modifications and that these magnetic nanoparticles can be efficiently utilized as biomolecule carriers in biosensing devices.

  12. Donnan-exclusion-driven distribution of catalytic ferromagnetic nanoparticles synthesized in polymeric fibers

    OpenAIRE

    Alonso González, Amanda; Macanás de Benito, Jorge; Shafir, Alexandr; Muñoz Tapia, Maria; Vallribera Massó, Adelina; Prodius, Denis; Melnic, Silvia; Turta, Constantin; Muraviev, Dmitri N

    2010-01-01

    One of the routes to overcome the high instability of metal nanoparticles (MNPs) lies in the use of polymeric materials for their synthesis and stabilization. Besides, one of the most serious concerns associated with the growing production and use of MNPs is the possibility of their uncontrollable escape into the medium under treatment and the environment. A possible solution to this problem could be the synthesis of ferromagnetic MNPs with desired functionality, that might not only prevent t...

  13. Phytoextracts-Synthesized Silver Nanoparticles Inhibit Bacterial Fish Pathogen Aeromonas hydrophila

    OpenAIRE

    Mahanty, Arabinda; Mishra, Snehasish; Bosu, Ranadhir; Maurya, UK; Netam, Surya Prakash; Sarkar, Biplab

    2013-01-01

    Fish disease is a major stumbling block towards sustainable growth of the fisheries sector. Aeromonas hydrophila, which is a major infectious aquatic pathogen is reportedly the causative agent of ulcers, fin-rot, tail-rot, hemorrhagic septicemia in fish, and has reportedly developed resistance against many of the available antibiotics. In this context, the inhibitory function of silver nanoparticles (AgNPs) against A. hydrophila was studied to evaluate its possible application in aquaculture ...

  14. Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tamboli, Dhawal P.; Lee, Dae Sung, E-mail: daesung@knu.ac.kr

    2013-09-15

    Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO{sub 3} solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis.

  15. Magnetic properties of Ni nanoparticles embedded in silica matrix (KIT-6) synthesized via novel chemical route

    International Nuclear Information System (INIS)

    Thermally stable Ni nanoparticles have been embedded in mesoporous silica matrix (KIT-6) via novel chemical reduction method by using superhydride as reducing agent. X-ray diffraction (XRD) study confirms that pure and embedded Ni nanoparticles crystallize in face centered cubic (fcc) structure. Crystallite sizes of pure Ni, 4 wt% and 8 wt% Ni in silica were estimated to be 6.0 nm, 10.4 nm and 10.5 nm, respectively. Morphology and dispersion of Ni in silica matrix were studied by scanning electron microscopy (SEM). Magnetic study shows enhancement of magnetic moments of Ni nanoparticles embedded in silica matrix compared with that of pure Ni. The result has been interpreted on the basis of size reduction and magnetic exchange effects. Saturation magnetization values for pure Ni, 4 wt% and 8 wt% Ni in silica were found to be 15.77 emu/g, 5.08 emu/g and 2.00 emu/g whereas coercivity values were 33.72 Oe, 92.47 Oe and 64.70 Oe, respectively. We anticipate that the observed magnetic properties may find application as soft magnetic materials

  16. Magnetic properties of Ni nanoparticles embedded in silica matrix (KIT-6) synthesized via novel chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Dalavi, Shankar B.; Panda, Rabi N., E-mail: rnp@goa.bits-pilani.ac.in [Department of Chemistry, BITS-Pilani, K. K. Birla Goa Campus, Zuarinagar, Goa-403726 (India); Raja, M. Manivel [Defence Metallurgical Research Laboratory, Hyderabad-500058 (India)

    2015-06-24

    Thermally stable Ni nanoparticles have been embedded in mesoporous silica matrix (KIT-6) via novel chemical reduction method by using superhydride as reducing agent. X-ray diffraction (XRD) study confirms that pure and embedded Ni nanoparticles crystallize in face centered cubic (fcc) structure. Crystallite sizes of pure Ni, 4 wt% and 8 wt% Ni in silica were estimated to be 6.0 nm, 10.4 nm and 10.5 nm, respectively. Morphology and dispersion of Ni in silica matrix were studied by scanning electron microscopy (SEM). Magnetic study shows enhancement of magnetic moments of Ni nanoparticles embedded in silica matrix compared with that of pure Ni. The result has been interpreted on the basis of size reduction and magnetic exchange effects. Saturation magnetization values for pure Ni, 4 wt% and 8 wt% Ni in silica were found to be 15.77 emu/g, 5.08 emu/g and 2.00 emu/g whereas coercivity values were 33.72 Oe, 92.47 Oe and 64.70 Oe, respectively. We anticipate that the observed magnetic properties may find application as soft magnetic materials.

  17. Surface-Enhanced Infrared Absorption of o-Nitroaniline on Nickel Nanoparticles Synthesized by Electrochemical Deposition

    Directory of Open Access Journals (Sweden)

    Yufang Niu

    2014-01-01

    Full Text Available Nickel nanoparticles were electrochemically deposited on indium-tin oxide (ITO coated glass plate in a modified Watt’s electrolyte. The surface-enhanced infrared absorption (SEIRA effect of the nanoparticles was evaluated by attenuated total reflection spectroscopy (ATR-FTIR using o-nitroaniline as a probe molecule. Electrodeposition parameters such as deposition time, pH value, and the type of surfactants were investigated. The morphology and the microstructure of the deposits were characterized by the field emission scanning electron microscope (FESEM and the atomic force microscope (AFM, respectively. The results indicate that the optimum parameters were potential of 1.3 V, time of 30 s, and pH of 8.92 in the solution of 0.3756 mol/L diethanolamine, 0.1 mol/L nickel sulfate, 0.01 mol/L nickel chloride, and 0.05 mol/L boric acid. The FESEM observation shows that the morphology of nickel nanoparticles with best enhancement effect is spherical and narrowly distributed particles with the average size of 50 nm. SEIRA enhancement factor is about 68.

  18. A Green Approach to Synthesize Silver Nanoparticles in Starch-co-Poly(acrylamide) Hydrogels by Tridax procumbens Leaf Extract and Their Antibacterial Activity

    OpenAIRE

    Siraj Shaik; Madhusudana Rao Kummara; Sudhakar Poluru; Chandrababu Allu; Jaffer Mohiddin Gooty; Chowdoji Rao Kashayi; Marata Chinna Subbarao Subha

    2013-01-01

    A series of starch-co-poly(acrylamide) (starch-co-PAAm) hydrogels were synthesized by employing free radical redox polymerization. A novel green approach, Tridax procumbens (TD) leaf extract, was used for reduction of silver ions (Ag+) into silver nanoparticles in the starch-co-PAAm hydrogel network. The formation of silver nanoparticles was confirmed by UV-visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TE...

  19. Effect of Polyethylene Glycol on the Formation of Magnetic Nanoparticles Synthesized by Magnetospirillum magnetotacticum MS-1

    OpenAIRE

    Hirokazu Shimoshige; Hideki Kobayashi; Toru Mizuki; Yutaka Nagaoka; Akira Inoue; Toru Maekawa

    2015-01-01

    Magnetotactic bacteria (MTB) synthesize intracellular magnetic nanocrystals called magnetosomes, which are composed of either magnetite (Fe3O4) or greigite (Fe3S4) and covered with lipid membranes. The production of magnetosomes is achieved by the biomineralization process with strict control over the formation of magnetosome membrane vesicles, uptake and transport of iron ions, and synthesis of mature crystals. These magnetosomes have high potential for both biotechnological and nanotechnolo...

  20. A Fluorescent Sensor Synthesized Using Silica Nanoparticles for Detecting Hg²⁺ in Aqueous Solution.

    Science.gov (United States)

    Zhao, Wenqi; Liu, Xingliang; Lv, Haitang; Fu, Hua; Huang, Ziping; Han, Aixia

    2016-01-01

    With the aim of detecting Hg²⁺ in aqueous solution, a new fluorescent nanosensor (RhB-APTES-SiNPs) for the determination of Hg²⁺ has been successfully developed. This senor was synthesized by immobilizing RhB-APTES on the surface of silica nanoparticles (SiNPs), which were prepared using the reverse microemulsion method. RhB-APTES-SiNPs can detect Hg²⁺ on-line, in real time and with the naked eye, thus providing "turn-on" fluorescence enhancement. The developed nanosensor exhibits highly sensitivity and selectivity over several cations in aqueous solution. Additionally, RhB-APTES-SiNPs exhibits an excellent ability to detect Hg²⁺ within a linear range from 1 to 6 µM, and its detection limit was calculated to be 0.5 ppb. PMID:27398518

  1. Apoptosis Induction in Human Leukemia Cell Lines by Gold Nanoparticles Synthesized Using the Green Biosynthetic Approach

    Directory of Open Access Journals (Sweden)

    Farideh Namvar

    2015-01-01

    Full Text Available Gold nanoparticles were grown on Sargassum muticum water extract (S-GNPs using the green biosynthetic approach. The nanoparticles were characterized using UV-visible spectroscopy, zeta potential, and transmission electron microscopy (TEM. The resulting S-GNPs were spherical and crystalline with a size of <10 nm. The in vitro anticancer activity was demonstrated in human leukemia cell lines. The cancer cells were treated with different concentrations of S-GNPs, and calorimetric (MTT assay used for the cytotoxicity test, which resulted in an IC50 value of 4.22 ± 1.12, 5.71 ± 1.4, 6.55 ± 0.9, and 7.29 ± 1.7 μg/mL for each of the K562, HL-60, Jurkat, and CEM-ss cells, respectively. Thus, the K562 was selected for the next experiments. Furthermore, apoptosis induction was confirmed by Hoechst 33342, annexin V staining, and caspase-3/-9 activity tests. The cell cycle analysis exhibited a significant increase in the accumulation of S-GNPs treated cells at the sub-G1 phase, demonstrating the induction of apoptosis by S-GNPs. The nature of the inhibition of cancer cell growth by S-GNPs could open the way for further research in the design of green synthesis therapeutic agents, particularly in nanomedicine, for the treatment of cancer.

  2. Study of Methylene Blue Degradation by Gold Nanoparticles Synthesized within Natural Zeolites

    Directory of Open Access Journals (Sweden)

    Ericka Rodríguez León

    2016-01-01

    Full Text Available We carried out the in situ synthesis of gold nanoparticles inside a natural clinoptilolite-type zeolite matrix, using ascorbic acid as reducing agent. The microstructure of both zeolite and zeolite-gold nanocomposite was characterized by X-ray diffraction (XRD, Scanning Electron Microscopy (SEM, Scanning Transmission Electron Microscopy (STEM, and Energy-Dispersive X-ray Spectroscopy (EDS techniques. Size distribution as assessed by STEM indicated that 60% of gold nanoparticles measured less than 2.5 nm. Determination of the surface area by the BET method revealed a specific value of 27.35 m2/g. The catalytic activity of zeolite-gold regarding methylene blue degradation under different light-exposing conditions was evaluated by UV-Vis spectroscopy. The results indicated that 50% degradation was achieved in only 11 min in presence of sunlight. This reaction was faster in comparison with those obtained using a white LED light. A notable aspect of this study is that catalysis was carried out without the addition of any strong reducing agents, such as sodium borohydride (NaBH4.

  3. Characterization and antimicrobial properties of cotton fabric loaded with green synthesized silver nanoparticles.

    Science.gov (United States)

    Ibrahim, Haytham M M; Hassan, Mahmoud S

    2016-10-20

    In the present study, antimicrobial formulations, based on silver nanoparticles (AgNPs) and butyl acrylate binder, were prepared and applied to a cotton fabric, followed by gamma-radiation or thermal curing, to protect it against the undesirable microbial effects. AgNPs were prepared by a biological method, using the biomass filtrate of fungus Alternaria alternata. Nanoparticles were characterized by UV-vis spectroscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and dynamic light scattering. Besides, the thermal stability, surface morphology, color strength, and mechanical properties of treated fabric were investigated. Treated cotton fabric showed good quantitative and qualitative antimicrobial activity; the bacterial reduction efficiency reached ∼100% for Escherichia coli and Staphylococcus aureus. They revealed excellent resistance to biodegradation caused by soil microflora. Moreover, they exhibited high durability of the attained antimicrobial activities, even after 20 washing cycles; where they achieved 99.1% and 98.7% reduction of E. coli and S. aureus bacterial counts, respectively. PMID:27474632

  4. Datura metel-synthesized silver nanoparticles magnify predation of dragonfly nymphs against the malaria vector Anopheles stephensi.

    Science.gov (United States)

    Murugan, Kadarkarai; Dinesh, Devakumar; Kumar, Prabhu Jenil; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Madhiyazhagan, Pari; Suresh, Udaiyan; Nicoletti, Marcello; Alarfaj, Abdullah A; Munusamy, Murugan A; Higuchi, Akon; Mehlhorn, Heinz; Benelli, Giovanni

    2015-12-01

    Malaria is a life-threatening disease caused by parasites transmitted to people and animals through the bites of infected mosquitoes. The employ of synthetic insecticides to control Anopheles populations leads to high operational costs, non-target effects, and induced resistance. Recently, plant-borne compounds have been proposed for efficient and rapid extracellular synthesis of mosquitocidal nanoparticles. However, their impact against predators of mosquito larvae has been poorly studied. In this study, we synthesized silver nanoparticles (AgNPs) using the Datura metel leaf extract as reducing and stabilizing agent. The biosynthesis of AgNPs was confirmed analyzing the excitation of surface plasmon resonance using ultraviolet-visible (UV-vis) spectroscopy. Scanning electron microscopy (SEM) showed the clustered and irregular shapes of AgNPs, with a mean size of 40-60 nm. The presence of silver was determined by energy-dispersive X-ray (EDX) spectroscopy. Fourier transform infrared (FTIR) spectroscopy analysis investigated the identity of secondary metabolites, which may be acting as AgNP capping agents. In laboratory, LC50 of D. metel extract against Anopheles stephensi ranged from 34.693 ppm (I instar larvae) to 81.500 ppm (pupae). LC50 of AgNP ranged from 2.969 ppm (I instar larvae) to 6.755 ppm (pupae). Under standard laboratory conditions, the predation efficiency of Anax immaculifrons nymphs after 24 h was 75.5 % (II instar larvae) and 53.5 % (III instar larvae). In AgNP-contaminated environment, predation rates were boosted to 95.5 and 78 %, respectively. Our results documented that D. metel-synthesized AgNP might be employed at rather low doses to reduce larval populations of malaria vectors, without detrimental effects on behavioral traits of young instars of the dragonfly Anax immaculifrons.

  5. Multidimensional effects of biologically synthesized silver nanoparticles in Helicobacter pylori, Helicobacter felis, and human lung (L132) and lung carcinoma A549 cells

    OpenAIRE

    Gurunathan, Sangiliyandi; Jeong, Jae-Kyo; Han, Jae Woong; Zhang, Xi-Feng; Park, Jung Hyun; Kim, Jin-Hoi

    2015-01-01

    Silver nanoparticles (AgNPs) are prominent group of nanomaterials and are recognized for their diverse applications in various health sectors. This study aimed to synthesize the AgNPs using the leaf extract of Artemisia princeps as a bio-reductant. Furthermore, we evaluated the multidimensional effect of the biologically synthesized AgNPs in Helicobacter pylori, Helicobacter felis, and human lung (L132) and lung carcinoma (A549) cells. UV-visible (UV–vis) spectroscopy confirmed the synthesis ...

  6. Properties of Co2FeAl Heusler Alloy Nano-particles Synthesized by Coprecipitation and Thermal Deoxidization Method

    Institute of Scientific and Technical Information of China (English)

    J.H.Du; Y.L.Zuo; Z.Wang; J.H.Ma; L.Xi

    2013-01-01

    Co2FeAl nanoparticles were synthesized by reducing the coprecipitated precursor of CoCl2·6H2O,Fe(NO3)3·9H2O and Al2(SO4)3·18H2O under H2 atmosphere with various annealing temperatures and durations.X-ray diffraction and transmission electron microscopy were used to characterize the crystal structure and microstructure of Co2FeAl particles,respectively.The investigation indicates that the crystal structure of Co2FeAl particles tends to be B2 structure,in which atoms are partially ordered.The saturation magnetization and hyperfine field of Co2FeAl particles,which were measured under a vibrating sample magnetometer and a 57Fe M(o)ssbauer spectroscope,are consistent with those of the bulk sample and thin films.Furthermore,the higher annealing temperature and the longer annealing time,the better crystallinity of Co2FeAl and more ordered arrangement of atoms will be.It turned out that the coprecipitation thermal deoxidization method could be an easy and high efficient way to obtain the half-metallic Co2FeAl nanoparticles.

  7. Field Test Of Capability To Prevent Cabbage Clubroot Disease Caused By Plasmodiophora brassicae Of Silver Nanoparticles Synthesized By Gamma Radiation

    International Nuclear Information System (INIS)

    The effects of four dose rates 0.27; 0.90; 1.80 and 3.60 kGy/h on the solution of silver (Ag+ 10-2 M, PVP 2%, ethylenglycol 6%) irradiated at 25 kGy were investigated. The results showed that as the dose rates increased, the absorption peak shifted to blue wavelengths and also the particles decreased in size. For field test, nano particles were prepared by irradiation of silver solution at 25 kGy with the dose rate of 3.60 kGy/h. The absorption peaks of the synthesized nanoparticles were obtained at wavelengths of 412 nm and the average diameter of particles were 14 nm. Using two concentrations of 15 and 20 ppm, silver nanoparticles had not affected the growth and development of cabbage but showed antifungal activity against Plasmodiophora brassicae cause club root in cabbage. Using nano particles, the clubroot disease index were 9-10% compared to 5% of nebijin (fungicide), and 12% of control. The yield of cabbage were 55 tons/ha, 63 tons/ha and 70 tons/ha for the control, nanosilver group, and nebijin group, respectively. (author)

  8. Silver nanoparticles synthesized using aqueous leaf extract of Ziziphus oenoplia (L.) Mill: Characterization and assessment of antibacterial activity.

    Science.gov (United States)

    Soman, Soumya; Ray, J G

    2016-10-01

    Biological approach to synthesis of metal nanoparticles using aqueous leaf extract is a highly relevant and recent theme in nanotechnological research. Phytosynthesized AgNPs have better inhibitory and antimicrobial effects compared to aqueous leaf extract and silver nitrate. In the present investigation crystalline silver nanoparticles (AgNPs) with size of 10nm have been successfully synthesized using aqueous leaf extract (AQLE) of Ziziphus oenoplia (L.) Mill., which act as both reducing as well as capping agent. The particles were characterized using UV Visible spectroscopy, HRTEM-EDAX, XRD, FT-IR and DLS. An evaluation of the anti bacterial activity was carried out using Agar well diffusion method and MIC determination against four bacterial strains, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi; the AgNPs exhibited quite high antibacterial activity. Furthermore, bactericidal studies with TEM at different time intervals after AgNPs treatment showed the presence of AgNPs near cell membrane of bacteria at about 30min exposure and the bacterial-lysis was found completed at 24h. This gave an insight on the mechanism of bacterial-lysis by direct damage to the cell membrane. PMID:27619740

  9. Exploring the dielectric behavior of Co doped ZnO nanoparticles synthesized by wet chemical route using impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Arshad, Mohd, E-mail: arshad_632000@yahoo.com [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Aligarh Muslim University, Aligarh (India); Ahmed, Arham S. [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Aligarh Muslim University, Aligarh (India); Azam, Ameer [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Aligarh Muslim University, Aligarh (India); Center of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Naqvi, A.H. [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Aligarh Muslim University, Aligarh (India)

    2013-11-15

    Highlights: •Co doped ZnO nanoparticles were synthesized using wet chemical route. •Particle size and lattice parameters decreased with Co doping. •Dominance of grain boundary contribution was observed in doped samples. •Dielectric constant and loss tangent reduced with Co doping. -- Abstract: In the present investigation, we report the synthesis of Co doped ZnO nanoparticles by wet chemical method with dopant content varying from 0% to 5%. The structural and dielectric properties of the samples were studied. Crystallite sizes were calculated from the X-ray diffraction (XRD) patterns, which were found to decrease with the increase in Co content. The XRD analysis also ensures that ZnO has a hexagonal (wurtzite) crystal structure and Co{sup 2+} ions were successfully incorporated into the lattice sites of Zn{sup 2+} ions. Dielectric constant was found to decrease with frequency and dopant concentration. Loss tangent results show the decrease in the hopping frequency of charge carriers between metal ions with doping.

  10. Screening of zinc oxide nanoparticles for cell proliferation synthesized through Adhatoda vasica nees

    OpenAIRE

    G. Bhumi; Y. Ratna Raju; N.Savithramma

    2014-01-01

    Nano science is the basic Study of systems and materials at the nanoscale. The objective of the present study focuses on the Phytoconstituent mediated biological synthesis of ZnO-NPs by Zinc acetate and sodium hydroxide by utilizing the biocomponents of leaves of Adhatoda vasica .The samples are characterized by UV-Vis Spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive Xray (EDAX), X-ray diffraction (XRD) and FT-Raman Spectroscopy. The Synthesized ZnO-NPs were found to be dis...

  11. Large CZTS Nanoparticles Synthesized by Hot-Injection for Thin Film Solar Cells

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    can be carried out in order to isolate the desired particle sizes, and films will be deposited through wet-chemical means. Mixing large NPs with small NPs can also improve the film-quality as a result of densification at the optimal packing density. The films are characterized by scanning electron......) solution processing to be a feasible fabrication route, the amount of carbon in the film has to be limited. In our work, we try to limit the organic material in the film by synthesizing larger NPs. Larger particles can be obtained by longer reaction durations, slower reaction rates of the precursors...

  12. Mosquitocidal and antibacterial activity of green-synthesized silver nanoparticles from Aloe vera extracts: towards an effective tool against the malaria vector Anopheles stephensi?

    Science.gov (United States)

    Dinesh, Devakumar; Murugan, Kadarkarai; Madhiyazhagan, Pari; Panneerselvam, Chellasamy; Kumar, Palanisamy Mahesh; Nicoletti, Marcello; Jiang, Wei; Benelli, Giovanni; Chandramohan, Balamurugan; Suresh, Udaiyan

    2015-04-01

    Mosquitoes represent an important threat for lives of millions of people worldwide, acting as vectors for devastating pathogens, such as malaria, yellow fever, dengue, and West Nile. In addition, pathogens and parasites polluting water also constitute a severe plague for populations of developing countries. Here, we investigated the mosquitocidal and antibacterial properties of Aloe vera leaf extract and silver nanoparticles synthesized using A. vera extract. Mosquitocidal properties were assessed in laboratory against larvae (I-IV instar) and pupae of the malaria vector Anopheles stephensi. Green-synthesized silver nanoparticles were tested against An. stephensi also in field conditions. Antibacterial properties of nanoparticles were evaluated against Bacillus subtilis, Klebsiella pneumoniae, and Salmonella typhi using the agar disk diffusion and minimum inhibitory concentration protocol. The synthesized silver nanoparticles were characterized by UV-vis spectrum, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In laboratory conditions, the A. vera extract was toxic against An. stephensi larvae and pupae, even at low dosages. LC50 were 48.79 ppm (I instar), 59.09 ppm (II instar), 70.88 ppm (III instar), 83.58 ppm (IV instar), and 152.55 ppm (pupae). Green-synthesized silver nanoparticles were highly toxic against An. stephensi. LC50 were 3.825 ppm (I instar), 4.119 ppm (II instar), 4.982 ppm (III instar), 5.711 ppm (IV instar), and 6.113 ppm (pupae). In field conditions, the application of A. vera-synthesized silver nanoparticles (10 × LC50) leads to An. stephensi larval reduction of 74.5, 86.6, and 97.7%, after 24, 48, and 72 h, respectively. Nanoparticles also showed antibacterial properties, and the maximum concentration tested (150 mg/L) evoked an inhibition zone wider than 80 mm in all tested bacterium species. This study adds knowledge about the use of green synthesis of nanoparticles in

  13. Size dependence of structure and magnetic properties of CoCr2O4 nanoparticles synthesized by hydrothermal technique

    Science.gov (United States)

    Tian, Zhaoming; Zhu, Changming; Wang, Junfeng; Xia, Zhengcai; Liu, Yong; Yuan, Songliu

    2015-03-01

    The size dependence of structure and magnetic behavior has been investigated on spinel chromite CoCr2O4 nanoparticles (NPs) with different particles from ~2.8 to ~19.7 nm, synthesized by a hydrothermal technique. The microstructure analysis shows that the lattice parameter increases monotonically with reduced particle sizes. Compared with the bulk sample, all synthesized NPs exhibit lower Curie temperature (TC~87 K) from paramagnetic (PM) to collinear short-range ferrimagnetic (FiM) state, and this PM-FiM transition is gradually degraded with decreased particle sizes and nearly vanishes for ~2.8 nm NPs. No magnetic transition from short-range FiM order to long-range spiral spin structure is found at low temperatures contrast to the bulk ones. Instead, a cluster spin-glass (SG) transition appears for NPs with D≤5.4 nm. The dynamic behavior of the cluster SG can be described by a power law with the spin relaxation time in the range of 10-10-10-8 s and critical exponent zv‧=9.9±0.6, in accordance with a three-dimensional Ising SG behavior. The glass transition temperature (Tg) decreases from 16.3 K for ~5.4 nm to 12.8 K for ~2.8 nm NPs.

  14. New procedure to synthesize silver nanoparticles and their interaction with local anesthetics

    Directory of Open Access Journals (Sweden)

    Mocanu A

    2013-10-01

    Full Text Available Aurora Mocanu,1 Roxana Diana Pasca,1 Gheorghe Tomoaia,2 Corina Garbo,1 Petre T Frangopol,1 Ossi Horovitz,1 Maria Tomoaia-Cotisel11Chemical Engineering Department, Babes-Bolyai University, 2Orthopedic Department, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, RomaniaAbstract: Silver nanoparticles (AgNPs were prepared in aqueous colloid dispersions by the reduction of Ag+ with glucose in alkaline medium. Tetraethyl orthosilicate and l-asparagine were added as stabilizers of NPs. The AgNPs were characterized, and their interaction with three local anesthetics (procaine, dibucaine, or tetracaine was investigated. Optical spectra show the characteristic absorption band of AgNPs, due to surface plasmon resonance. Modifications in the position and shape of this band reflect the self-assembly of metal NPs mediated by anesthetic molecules and the progress in time of the aggregation process. Zeta-potential measuring was applied in order to characterize the electrostatic stability of the NPs. The size and shape of the AgNPs, as well as the features of the assemblies formed by their association in the presence of anesthetics, were evidenced by transmission electron microscopy images. Atomic force microscopy images showed the characteristics of the films of AgNPs deposited on glass support. The effect of the anesthetics could be described in terms of electrostatic forces between the negatively charged AgNPs and the anesthetic molecules, existing also in their cationic form at the working pH. But also hydrophobic and hydrogen bonding interactions between the coated nanoparticles and anesthetics molecular species should be considered.Keywords: self-assembled nanostructures, UV-vis spectra, TEM, AFM, zeta potential

  15. Antibacterial properties of silver nanoparticles synthesized using Pulicaria glutinosa plant extract as a green bioreductant

    Directory of Open Access Journals (Sweden)

    Khan M

    2014-07-01

    Full Text Available Mujeeb Khan,1 Shams Tabrez Khan,2 Merajuddin Khan,1 Syed Farooq Adil,1 Javed Musarrat,2 Abdulaziz A Al-Khedhairy,2 Abdulrahman Al-Warthan,1 Mohammed Rafiq H Siddiqui,1 Hamad Z Alkhathlan1 1Department of Chemistry, 2Zoology Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia Abstract: The antibacterial properties of nanoparticles (NPs can be significantly enhanced by increasing the wettability or solubility of NPs in aqueous medium. In this study, we investigated the effects of the stabilizing agent on the solubility of silver NPs and its subsequent effect on their antimicrobial activities. Silver NPs were prepared using an aqueous solution of Pulicaria glutinosa plant extract as bioreductant. The solution also acts as a capping ligand. During this study, the antimicrobial activities of silver NPs, as well as the plant extract alone, were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Micrococcus luteus. Silver NPs were prepared with various concentrations of the plant extract to study its effect on antimicrobial activity. Interestingly, various concentrations of P. glutinosa extract did not show any effect on the growth of tested bacteria; however, a significant effect on the antimicrobial property of plant extract capped silver NPs (Ag-NPs-PE was observed. For instance, the half maximal inhibitory concentration values were found to decrease (from 4% to 21% with the increasing concentrations of plant extract used for the synthesis of Ag-NPs-PE. These results clearly indicate that the addition of P. glutinosa extracts enhances the solubility of Ag-NPs-PE and, hence, increases their toxicity against the tested microorganisms. Keywords: antibacterial activity, silver nanoparticles, plant extract, Pulicaria glutinosa

  16. Thermal Instability and Microstructure of Strontium M-type Hexaferrite Nanoparticles Synthesized by Citrate Approach

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wenyu; ZHANG Qingjie; GUAN Jianguo

    2006-01-01

    The dried gel of SrFe12O19, prepared by citrate approach, was investigated by means of infrared spectroscopy (IR), thermogravimetric analysis(TG), differential scanning calorimetry(DSC), X-ray diffraction(XRD) techniques, energy dispersive spectroscopy(EDS), and transmission electron microscopy(TEM). The thermal instability and the thermal decomposition of low-temperature strontium M-type hexaferrite crystallized at about 600 ℃ were confirmed for the first time by XRD method. The decomposition of the low-temperature strontium M-type hexaferrite took place at about 688.6 ℃ determined by DSC investigation. The low-temperature strontium M-type hexaferrite nanoparticles were decomposed into SrFeO2.5 with an orthorthombic cell and Fe2O3 with a tetragonal cell as well as possibl α-Fe2O3. The agglomerated particles with sizes less than 200 nm obtained at 800 ℃ were plesiomorphous to strontium M-type hexaferrite. The thermally stable strontium M-type hexaferrite nanoparticles with sizes less than 100nm could take place at 900 ℃. Up to 1000 ℃, the phase transformation to form strontium M-type hexaferrite was ended, the calcinations with the sizes more than 1μm were composed of α-Fe2O3 and strontium M-type hexaferrite. The method of distinguishing γ-Fe2O3 with a spinel structure from Fe2O3 with tetragonal cells by using powder XRD method was proposed. Fe2O3 with tetragonal cells to be crystallized before the crystallization of thermally stable strontium M-type hexaferrite was confirmed for the first time. The reason why α-Fe2O3 as an additional phase appears in the calcinations is the cationic vacancy of strontium M-type hexaferrite, SrFe12-x()xO19 (0≤x≤0.5).

  17. Adulticidal properties of synthesized silver nanoparticles using leaf extracts of Feronia elephantum (Rutaceae) against filariasis, malaria, and dengue vector mosquitoes.

    Science.gov (United States)

    Veerakumar, Kaliyan; Govindarajan, Marimuthu

    2014-11-01

    Mosquito-borne diseases with an economic impact create loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Extracts from plants may be alternative sources of mosquito control agents because they constitute a rich source of bioactive compounds that are biodegradable into nontoxic products and potentially suitable for use to control mosquitoes. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Feronia elephantum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. The range of concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg mL(-1)) and aqueous leaf extract (40, 80, 120, 160, and 200 μg mL(-1)) were tested against the adults of A. stephensi, A. aegypti, and C. quinquefasciatus. Adults were exposed to varying concentrations of aqueous crude extract and synthesized AgNPs for 24 h. Considerable mortality was evident after the treatment of F. elephantum for all three important vector mosquitoes. The synthesized AgNPs from F. elephantum were highly toxic than crude leaf aqueous extract to three important vector mosquito species. The results were recorded from UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy analysis (EDX), and transmission electron microscopy (TEM). Synthesized AgNPs against the vector mosquitoes A. stephensi, A. aegypti, and C. quinquefasciatus had the following lethal dose (LD)₅₀ and LD₉₀ values: A. stephensi had LD₅₀ and LD₉₀ values of 18

  18. Eco-friendly microbial route to synthesize cobalt nanoparticles using Bacillus thuringiensis against malaria and dengue vectors.

    Science.gov (United States)

    Marimuthu, Sampath; Rahuman, Abdul Abdul; Kirthi, Arivarasan Vishnu; Santhoshkumar, Thirunavukkarasu; Jayaseelan, Chidambaram; Rajakumar, Govindasamy

    2013-12-01

    The developments of resistance and persistence to chemical insecticides and concerns about the non-target effects have prompted the development of eco-friendly mosquito control agents. The aim of this study was to investigate the larvicidal activities of synthesized cobalt nanoparticles (Co NPs) using bio control agent, Bacillus thuringiensis against malaria vector, Anopheles subpictus and dengue vector, Aedes aegypti (Diptera: Culicidae). The synthesized Co NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy, and Transmission electron microscopy (TEM). XRD analysis showed three distinct diffraction peaks at 27.03°, 31.00°, and 45.58° indexed to the planes 102, 122, and 024, respectively on the face-centered cubic cobalt acetate with an average size of 85.3 nm. FTIR spectra implicated role of the peak at 3,436 cm(-1) for O-H hydroxyl group, 2924 cm(-1) for methylene C-H stretch in the formation of Co NPs. FESEM analysis showed the topological and morphological appearance of NPs which were found to be spherical and oval in shape. TEM analysis showed polydispersed and clustered NPs with an average size of 84.81 nm. The maximum larvicidal mortality was observed in the cobalt acetate solution, B. thuringiensis formulation, and synthesized Co NPs against fourth instar larvae of A. subpictus and A. aegypti with LC50 values of 29.16, 8.12, 3.59 mg/L; 34.61, 6.94, and 2.87 mg/L; r (2) values of 0.986, 0.933, 0.942; 0.962, 0.957, and 0.922, respectively.

  19. Investigation of laundering and dispersion approaches for silica and calcium phosphosilicate composite nanoparticles synthesized in reverse micelles

    Science.gov (United States)

    Tabakovic, Amra

    Nanotechnology, the science and engineering of materials at the nanoscale, is a booming research area with numerous applications in electronic, cosmetic, automotive and sporting goods industries, as well as in biomedicine. Composite nanoparticles (NPs) are of special interest since the use of two or more materials in NP design imparts multifunctionality on the final NP constructs. This is especially relevant for applications in areas of human healthcare, where the use of dye or drug doped composite NPs is expected to improve the diagnosis and treatment of cancer and other serious illnesses. Since the physicochemical properties of NP suspensions dictate the success of these systems in biomedical applications, especially drug delivery of chemotherapeutics, synthetic routes which offer precise control of NP properties, especially particle diameter and colloidal stability, are utilized to form a variety of composite NPs. Formation of NPs in reverse, or water-in-oil, micelles is one such synthetic approach. However, while the use of reverse micelles to form composite NPs offers precise control over NP size and shape, the post-synthesis laundering and dispersion of synthesized NP suspensions can still be a challenge. Reverse micelle synthetic approaches require the use of surfactants and low dielectric constant solvents, like hexane and cyclohexane, as the oil phase, which can compromise the biocompatibility and colloidal stability of the final composite NP suspensions. Therefore, appropriate dispersants and solvents must be used during laundering and dispersion to remove surfactant and ensure stability of synthesized NPs. In the work presented in this dissertation, two laundering and dispersion approaches, including packed column high performance liquid chromatography (HPLC) and centrifugation (sedimentation and redispersion), are investigated for silver core silica (Ag-SiO2) and calcium phosphosilicate (Caw(HxPO4)y(Si(OH)zOa) b · cH2O, CPS) composite NP suspensions

  20. Biologically Synthesized Gold Nanoparticles Ameliorate Cold and Heat Stress-Induced Oxidative Stress in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Xi-Feng Zhang

    2016-06-01

    Full Text Available Due to their unique physical, chemical, and optical properties, gold nanoparticles (AuNPs have recently attracted much interest in the field of nanomedicine, especially in the areas of cancer diagnosis and photothermal therapy. Because of the enormous potential of these nanoparticles, various physical, chemical, and biological methods have been adopted for their synthesis. Synthetic antioxidants are dangerous to human health. Thus, the search for effective, nontoxic natural compounds with effective antioxidative properties is essential. Although AuNPs have been studied for use in various biological applications, exploration of AuNPs as antioxidants capable of inhibiting oxidative stress induced by heat and cold stress is still warranted. Therefore, one goal of our study was to produce biocompatible AuNPs using biological methods that are simple, nontoxic, biocompatible, and environmentally friendly. Next, we aimed to assess the antioxidative effect of AuNPs against oxidative stress induced by cold and heat in Escherichia coli, which is a suitable model for stress responses involving AuNPs. The response of aerobically grown E. coli cells to cold and heat stress was found to be similar to the oxidative stress response. Upon exposure to cold and heat stress, the viability and metabolic activity of E. coli was significantly reduced compared to the control. In addition, levels of reactive oxygen species (ROS and malondialdehyde (MDA and leakage of proteins and sugars were significantly elevated, and the levels of lactate dehydrogenase activity (LDH and adenosine triphosphate (ATP significantly lowered compared to in the control. Concomitantly, AuNPs ameliorated cold and heat-induced oxidative stress responses by increasing the expression of antioxidants, including glutathione (GSH, glutathione S-transferase (GST, super oxide dismutase (SOD, and catalase (CAT. These consistent physiology and biochemical data suggest that AuNPs can ameliorate cold and

  1. Room temperature ferromagnetism in liquid-phase pulsed laser ablation synthesized nanoparticles of nonmagnetic oxides

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S. C., E-mail: subhash.laserlab@gmail.com; Gopal, R. [Laser Spectroscopy and Nanomaterials Lab, Department of Physics, University of Allahabad, Allahabad-211002 (India); Kotnala, R. K. [Magnetic Standardization Division, National Physical Laboratory, K.S. Krishnan Road, New Delhi (India)

    2015-08-14

    Intrinsic Room Temperature Ferromagnetism (RTF) has been observed in undoped/uncapped zinc oxide and titanium dioxide spherical nanoparticles (NPs) obtained by a purely green approach of liquid phase pulsed laser ablation of corresponding metal targets in pure water. Saturation magnetization values observed for zinc oxide (average size, 9 ± 1.2 nm) and titanium dioxide (average size, 4.4 ± 0.3 nm) NPs are 62.37 and 42.17 memu/g, respectively, which are several orders of magnitude larger than those of previous reports. In contrast to the previous works, no postprocessing treatments or surface modification is required to induce ferromagnetism in the case of present communication. The most important result, related to the field of intrinsic ferromagnetism in nonmagnetic materials, is the observation of size dependent ferromagnetism. Degree of ferromagnetism in titanium dioxide increases with the increase in particle size, while it is reverse for zinc oxide. Surface and volume defects play significant roles for the origin of RTF in zinc oxide and titanium dioxide NPs, respectively. Single ionized oxygen and neutral zinc vacancies in zinc oxide and oxygen and neutral/ionized titanium vacancies in titanium dioxide are considered as predominant defect centres responsible for observed ferromagnetism. It is expected that origin of ferromagnetism is a consequence of exchange interactions between localized electron spin moments resulting from point defects.

  2. Resistive Switching of Individual, Chemically Synthesized TiO2 Nanoparticles.

    Science.gov (United States)

    Schmidt, Dirk Oliver; Hoffmann-Eifert, Susanne; Zhang, Hehe; La Torre, Camilla; Besmehn, Astrid; Noyong, Michael; Waser, Rainer; Simon, Ulrich

    2015-12-22

    Resistively switching devices are considered promising for next-generation nonvolatile random-access memories. Today, such memories are fabricated by means of "top-down approaches" applying thin films sandwiched between nanoscaled electrodes. In contrast, this work presents a "bottom-up approach" disclosing for the first time the resistive switching (RS) of individual TiO2 nanoparticles (NPs). The NPs, which have sizes of 80 and 350 nm, respectively, are obtained by wet chemical synthesis and thermally treated under oxidizing or vacuum conditions for crystallization, respectively. These NPs are deposited on a Pt/Ir bottom electrode and individual NPs are electrically characterized by means of a nanomanipulator system in situ, in a scanning electron microscope. While amorphous NPs and calcined NPs reveal no switching hysteresis, a very interesting behavior is found for the vacuum-annealed, crystalline TiO(2-x) NPs. These NPs reveal forming-free RS behavior, dominantly complementary switching (CS) and, to a small degree, bipolar switching (BS) characteristics. In contrast, similarly vacuum-annealed TiO2 thin films grown by atomic layer deposition show standard BS behavior under the same conditions. The interesting CS behavior of the TiO(2-x) NPs is attributed to the formation of a core-shell-like structure by re-oxidation of the reduced NPs as a unique feature. PMID:26540646

  3. Hybrid palm-oil/styrene-maleimide nanoparticles synthesized in aqueous dispersion under different conditions.

    Science.gov (United States)

    Samyn, Pieter; Van Nieuwkerke, Dieter; Schoukens, Gustaaf; Stanssens, Dirk; Vonck, Leo; Van den Abbeele, Henk

    2015-01-01

    Poly(styrene-co-maleic anhydride) was imidized with ammonium hydroxide and palm oil, resulting in an aqueous dispersion of hybrid nanoparticles with diameters 85-180 nm (dispersed) or 20-50 nm (dried). The reaction conditions were optimized for different precursors by evaluating the relative amount ammonium hydroxide and maximizing the incorporated palm oil up to 70 wt.%. The interactions between palm oil and polymer phase have been studied by TEM, IR, Raman spectroscopy and thermal analysis (TGA, [TM] DSC). From Raman spectra, the amount of imide and reacted oil were quantified. Through concurring effects of imidization and coupling of fatty acids, the imidization needs a slight excess of NH3 relatively to maleic anhydride. The oxidative stability highly depends on oxidative crosslinking of free or non-reacted oil. Comparing the imide content from spectroscopic and thermal analysis suggests that a complex rigid imide phase without strong relaxation behavior has formed in combination with oil.

  4. Antibacterial properties of silver nanoparticles synthesized using Pulicaria glutinosa plant extract as a green bioreductant.

    Science.gov (United States)

    Khan, Mujeeb; Khan, Shams Tabrez; Khan, Merajuddin; Adil, Syed Farooq; Musarrat, Javed; Al-Khedhairy, Abdulaziz A; Al-Warthan, Abdulrahman; Siddiqui, Mohammed Rafiq H; Alkhathlan, Hamad Z

    2014-01-01

    The antibacterial properties of nanoparticles (NPs) can be significantly enhanced by increasing the wettability or solubility of NPs in aqueous medium. In this study, we investigated the effects of the stabilizing agent on the solubility of silver NPs and its subsequent effect on their antimicrobial activities. Silver NPs were prepared using an aqueous solution of Pulicaria glutinosa plant extract as bioreductant. The solution also acts as a capping ligand. During this study, the antimicrobial activities of silver NPs, as well as the plant extract alone, were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Micrococcus luteus. Silver NPs were prepared with various concentrations of the plant extract to study its effect on antimicrobial activity. Interestingly, various concentrations of P. glutinosa extract did not show any effect on the growth of tested bacteria; however, a significant effect on the antimicrobial property of plant extract capped silver NPs (Ag-NPs-PE) was observed. For instance, the half maximal inhibitory concentration values were found to decrease (from 4% to 21%) with the increasing concentrations of plant extract used for the synthesis of Ag-NPs-PE. These results clearly indicate that the addition of P. glutinosa extracts enhances the solubility of Ag-NPs-PE and, hence, increases their toxicity against the tested microorganisms.

  5. Antibacterial activity of silver nanoparticles synthesized In-situ by solution spraying onto cellulose.

    Science.gov (United States)

    Yan, Jinhua; Abdelgawad, Abdelrahman M; El-Naggar, Mehrez E; Rojas, Orlando J

    2016-08-20

    Spray technique was used for the adsorption of in-situ silver nanoparticles (AgNPs) onto and inside the surface of nano- and micro- fibrillar cellulose (NFC and MFC) as well as filter paper. The abundance of hydroxyl and carboxyl groups located in NFC and MFC are used to stabilize Ag ions (Ag(+)) which were then in-situ reduced to (AgNPs) by chemical or UV reduction. The surface characteristic features, elemental analysis, particle size as well as size distribution of the obtained MFC, NFC and filter paper loaded with AgNPs were characterized via field emission scanning electron microscopy connected to energy dispersive X-ray spectroscopy (FESEM- EDX) and transmission electron microscopy (TEM). The associated chemical changes after growth of AgNPs onto the cellulose substrates were assessed by fourier transform infra-red (FT-IR) while the thermal stability of such systems were investigated by thermogravimetrical analyses (TGA). The antibacterial properties of AgNPs loaded NFC, MFC and filter paper as well was investigated against Escherichia Coli. The resulted data indicate that the particle size was found to be 11 and 26nm for AgNPs nucleated on NFC and MFC-based papers respectively. The antibacterial activity of AgNPs loaded MFC exhibited higher antibacterial activity than that of AgNPs loaded NFC. Overall, the present research demonstrates facile and fast method for in-situ antibacterial AgNPs loading on cellulose substrates. PMID:27178957

  6. A New Method of Synthesizing Black Birnessite Nanoparticles: From Brown to Black Birnessite with Nanostructures

    Directory of Open Access Journals (Sweden)

    Marcos A. Cheney

    2008-01-01

    Full Text Available A new method for preparing black birnessite nanoparticles is introduced. The initial synthesis process resembles the classical McKenzie method of preparing brown birnessite except for slower cooling and closing the system from the ambient air. Subsequent process, including wet-aging at 7∘C for 48 hours, overnight freezing, and lyophilization, is shown to convert the brown birnessite into black birnessite with complex nanomorphology with folded sheets and spirals. Characterization of the product is performed by X-ray diffraction (XRD, transmission electron microscopy (TEM, high-resolution transmission electron microscopy (HRTEM, thermogravimetric analysis (TGA, and N2 adsorption (BET techniques. Wet-aging and lyophilization times are shown to affect the architecture of the product. XRD patterns show a single phase corresponding to a semicrystalline birnessite-based manganese oxide. TEM studies suggest its fibrous and petal-like structures. The HRTEM images at 5 and 10 nm length scales reveal the fibrils in folding sheets and also show filamentary breaks. The BET surface area of this nanomaterial was found to be 10.6 m2/g. The TGA measurement demonstrated that it possessed an excellent thermal stability up to 400∘C. Layer-structured black birnessite nanomaterial containing sheets, spirals, and filamentary breaks can be produced at low temperature (−49∘C from brown birnessite without the use of cross-linking reagents.

  7. Oxidation of o-chloro and o-hydroxy benzyl alcohols catalyzed by copper (II tetraphenylporphyrin nanoparticles synthesized by mixed solvent method

    Directory of Open Access Journals (Sweden)

    Rahmatollah Rahimi

    2012-07-01

    Full Text Available Tetraphenylporphyrin (TPP and copper tetraphenylporphyrin (CuTPP were synthesized and characterized by IR, UV-Vis, 1HNMR and 13CNMR. The CuTPP nanoparticles were synthesized by sonication and mixed solvent methods. These nanoparticles were characterized by AFM and SEM images and UV-Vis spectra. The catalytic activity of nanoparticles was investigated by oxidation of o-choloro and o-hydroxy benzyl alcohols in presence of molecular oxygen and isobutyraldehyde. The yields of oxidation of o-hydroxy benzyl alcohol by the two catalysts, CuTPP NPs and CuTPP, are 96.5% and ~ 2%, respectively. It is very obvious that the oxidation at the presence of CuTPP NPs catalyst is very high but selectivity for both reactants is 100%.‎

  8. A simple way to obtain high saturation magnetization for superparamagnetic iron oxide nanoparticles synthesized in air atmosphere: Optimization by experimental design

    Science.gov (United States)

    Karaagac, Oznur; Kockar, Hakan

    2016-07-01

    Orthogonal design technique was applied to obtain superparamagnetic iron oxide nanoparticles with high saturation magnetization, Ms. Synthesis of the nanoparticles were done in air atmosphere according to the orthogonal table L934. Magnetic properties of the synthesized nanoparticles were measured by a vibrating sample magnetometer. Structural analysis of the nanoparticles was also carried out by X-ray diffraction technique (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). After the analysis of magnetic data, the optimized experimental parameters were determined as [Fe+2]/[Fe+3]=6/6, iron ion concentration=1500 mM, base concentration=6.7 M and reaction time=2 min. Magnetic results showed that the synthesis carried out according to the optimized conditions gave the highest Ms of 69.83 emu/g for the nanoparticles synthesized in air atmosphere. Magnetic measurements at 10 K and 300 K showed the sample is superparamagnetic at room temperature. Structural analysis by XRD, FTIR and selected area electron diffraction showed that the sample had the inverse spinel crystal structure of iron oxide. The particle size of the optimized sample determined from the TEM image is 7.0±2.2 nm. The results indicated that the Ms of superparamagnetic iron oxide nanoparticles can be optimized by experimental design with the suitable choice of the synthesis parameters.

  9. Oxide or carbide nanoparticles synthesized by laser ablation of a bulk Hf target in liquids and their structural, optical, and dielectric properties

    Science.gov (United States)

    Semaltianos, N. G.; Friedt, J.-M.; Chassagnon, R.; Moutarlier, V.; Blondeau-Patissier, V.; Combe, G.; Assoul, M.; Monteil, G.

    2016-05-01

    Laser ablation of a bulk Hf target in deionized (DI) water, ethanol, or toluene was carried out for the production of nanoparticles' colloidal solutions. Due to the interaction of the ablation plasma plume species with the species which are produced by the liquid decomposition at the plume-liquid interface, hafnia (HfO2) nanoparticles are synthesized in DI water, hafnium carbide (HfC) nanoparticles in toluene, and a mixture of these in ethanol. The hafnia nanoparticles are in the monoclinic low temperature phase and in the tetragonal and fcc high temperature phases. Their size distribution follows log-normal function with a median diameter in the range of 4.3-5.3 nm. Nanoparticles synthesized in DI water have band gaps of 5.6 and 5.4 eV, in ethanol 5.72 and 5.65 eV (using low and high pulse energy), and in toluene 3 eV. The values for the relative permittivity in the range of 7.74-8.90 were measured for hafnia nanoparticles' thin films deposited on substrates by drop-casting (self-assembled layers) in parallel plate capacitor structures.

  10. Reductive reactivity of borohydride- and dithionite-synthesized iron-based nanoparticles: A comparative study.

    Science.gov (United States)

    Ma, Xiaoming; He, Di; Jones, Adele M; Collins, Richard N; Waite, T David

    2016-02-13

    In this study sodium dithionite (NaS2O4) and sodium borohydride (NaBH4) were employed as reducing agents for the synthesis of nanosized iron-based particles. The particles formed using NaBH4 (denoted nFe(BH4)) principally contained (as expected) Fe(0) according to XAS and XRD analyses while the particles synthesized using NaS2O4, (denoted nFe(S2O4)) were dominated by the mixed Fe(II)/Fe(III) mineral magnetite (Fe3O4) though with possible presence of Fe(0). The ability of both particles to reduce trichloroethylene (TCE) under analogous conditions demonstrated remarkable differences with nFe(BH4) resulting in complete reduction of 1.5mM of TCE in 2h while nFe(S2O4) were unable to effect complete reduction of TCE in 120 h. Moreover, acetylene was the major reaction product formed in the presence of nFe(S2O4) while the major reaction product formed following reaction with nFe(BH4) was ethylene, which was further reduced to ethane as the reaction proceeded. Considering that effective Pd reduction to Pd(0) requires the presence of Fe(0), this is consistent with our finding that Fe(0) is not the dominant phase formed when employing dithionite as a reducing agent under the conditions employed in this study. PMID:26513569

  11. Effect of Polyethylene Glycol on the Formation of Magnetic Nanoparticles Synthesized by Magnetospirillum magnetotacticum MS-1.

    Directory of Open Access Journals (Sweden)

    Hirokazu Shimoshige

    Full Text Available Magnetotactic bacteria (MTB synthesize intracellular magnetic nanocrystals called magnetosomes, which are composed of either magnetite (Fe3O4 or greigite (Fe3S4 and covered with lipid membranes. The production of magnetosomes is achieved by the biomineralization process with strict control over the formation of magnetosome membrane vesicles, uptake and transport of iron ions, and synthesis of mature crystals. These magnetosomes have high potential for both biotechnological and nanotechnological applications, but it is still extremely difficult to grow MTB and produce a large amount of magnetosomes under the conventional cultural conditions. Here, we investigate as a first attempt the effect of polyethylene glycol (PEG added to the culture medium on the increase in the yield of magnetosomes formed in Magnetospirillum magnetotacticum MS-1. We find that the yield of the formation of magnetosomes can be increased up to approximately 130 % by adding PEG200 to the culture medium. We also measure the magnetization of the magnetosomes and find that the magnetosomes possess soft ferromagnetic characteristics and the saturation mass magnetization is increased by 7 %.

  12. Effect of Polyethylene Glycol on the Formation of Magnetic Nanoparticles Synthesized by Magnetospirillum magnetotacticum MS-1.

    Science.gov (United States)

    Shimoshige, Hirokazu; Kobayashi, Hideki; Mizuki, Toru; Nagaoka, Yutaka; Inoue, Akira; Maekawa, Toru

    2015-01-01

    Magnetotactic bacteria (MTB) synthesize intracellular magnetic nanocrystals called magnetosomes, which are composed of either magnetite (Fe3O4) or greigite (Fe3S4) and covered with lipid membranes. The production of magnetosomes is achieved by the biomineralization process with strict control over the formation of magnetosome membrane vesicles, uptake and transport of iron ions, and synthesis of mature crystals. These magnetosomes have high potential for both biotechnological and nanotechnological applications, but it is still extremely difficult to grow MTB and produce a large amount of magnetosomes under the conventional cultural conditions. Here, we investigate as a first attempt the effect of polyethylene glycol (PEG) added to the culture medium on the increase in the yield of magnetosomes formed in Magnetospirillum magnetotacticum MS-1. We find that the yield of the formation of magnetosomes can be increased up to approximately 130 % by adding PEG200 to the culture medium. We also measure the magnetization of the magnetosomes and find that the magnetosomes possess soft ferromagnetic characteristics and the saturation mass magnetization is increased by 7 %. PMID:25993286

  13. Microstructure, electronic structure and optical properties of combustion synthesized Co doped ZnO nanoparticles

    Science.gov (United States)

    Srinatha, N.; Nair, K. G. M.; Angadi, Basavaraj

    2015-10-01

    We report on the microstructure, electronic structure and optical properties of nanocrystalline Zn1-xCoxO (x=0, 0.01, 0.03, 0.05 and 0.07) particles prepared by solution combustion technique using L-Valine as fuel. The detailed structural and micro-structural studies were carried out by XRD, HRTEM and TEM-SAED respectively, which confirms the formation of single phased, nano-sized particles. The electronic structure was determined through NEXAFS and atomic multiplet calculations/simulations performed for various symmetries and valence states of 'Co' to determine the valance state, symmetry and crystal field splitting. The correlations between the experimental NEXAFS spectra and atomic multiplet simulations, confirms that, 'Co' present is in the 2+ valence state and substituted at the 'Zn' site in tetrahedral symmetry with crystal field splitting, 10Dq =-0.6 eV. The optical properties and 'Co' induced defect formation of as-synthesized materials were examined by using diffuse reflectance and Photoluminescence spectroscopy, respectively. Red-shift of band gap energy (Eg) was observed in Zn1-xCoxO samples due to Co (0.58 Å) substitution at Zn (0.60 Å) site of the host ZnO. Also, in PL spectra, a prominent pre-edge peak corresponds to ultraviolet (UV) emission around 360-370 nm was observed with Co concentration along with near band edge emission (NBE) of the wide band gap ZnO and all samples show emission in the blue region.

  14. Microstructure, electronic structure and optical properties of combustion synthesized Co doped ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Srinatha, N. [Department of Physics, JB Campus, Bangalore University, Bangalore 560056 (India); Nair, K.G.M. [UGC-DAE-CSR, Kalpakkam Node, Kalpakkam, Kokilamedu 603102 (India); Angadi, Basavaraj, E-mail: brangadi@gmail.com [Department of Physics, JB Campus, Bangalore University, Bangalore 560056 (India)

    2015-10-01

    We report on the microstructure, electronic structure and optical properties of nanocrystalline Zn{sub 1−x}Co{sub x}O (x=0, 0.01, 0.03, 0.05 and 0.07) particles prepared by solution combustion technique using L-Valine as fuel. The detailed structural and micro-structural studies were carried out by XRD, HRTEM and TEM-SAED respectively, which confirms the formation of single phased, nano-sized particles. The electronic structure was determined through NEXAFS and atomic multiplet calculations/simulations performed for various symmetries and valence states of ‘Co’ to determine the valance state, symmetry and crystal field splitting. The correlations between the experimental NEXAFS spectra and atomic multiplet simulations, confirms that, ‘Co’ present is in the 2+ valence state and substituted at the ‘Zn’ site in tetrahedral symmetry with crystal field splitting, 10Dq =−0.6 eV. The optical properties and ‘Co’ induced defect formation of as-synthesized materials were examined by using diffuse reflectance and Photoluminescence spectroscopy, respectively. Red-shift of band gap energy (E{sub g}) was observed in Zn{sub 1−x}Co{sub x}O samples due to Co (0.58 Å) substitution at Zn (0.60 Å) site of the host ZnO. Also, in PL spectra, a prominent pre-edge peak corresponds to ultraviolet (UV) emission around 360–370 nm was observed with Co concentration along with near band edge emission (NBE) of the wide band gap ZnO and all samples show emission in the blue region.

  15. S argassum muticum-synthesized silver nanoparticles: an effective control tool against mosquito vectors and bacterial pathogens.

    Science.gov (United States)

    Madhiyazhagan, Pari; Murugan, Kadarkarai; Kumar, Arjunan Naresh; Nataraj, Thiyagarajan; Dinesh, Devakumar; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Mahesh Kumar, Palanisamy; Suresh, Udaiyan; Roni, Mathath; Nicoletti, Marcello; Alarfaj, Abdullah A; Higuchi, Akon; Munusamy, Murugan A; Benelli, Giovanni

    2015-11-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. Furthermore, pathogens and parasites polluting water also constitute a severe plague for populations of developing countries. In this research, silver nanoparticles (AgNP) were synthesized using the aqueous extract of the seaweed Sargassum muticum. The production of AgNP was confirmed by surface plasmon resonance band illustrated in UV-vis spectrophotometry. AgNP were characterized by FTIR, SEM, EDX, and XRD analyses. AgNP were mostly spherical in shape, crystalline in nature, with face-centered cubic geometry, and mean size was 43-79 nm. Toxicity of AgNP was assessed against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. In laboratory, AgNP were highly toxic against larvae and pupae of the three mosquito species. Maximum efficacy was observed against A. stephensi larvae, with LC50 ranging from 16.156 ppm (larva I) to 28.881 ppm (pupa). In the field, a single treatment with AgNP (10 × LC50) in water storage reservoirs was effective against the three mosquito vectors, allowing complete elimination of larval populations after 72 h. In ovicidal experiments, egg hatchability was reduced by 100% after treatment with 30 ppm of AgNP. Ovideterrence assays highlighted that 10 ppm of AgNP reduced oviposition rates of more than 70% in A. aegypti, A. stephensi, and C. quinquefasciatus (OAI = -0.61, -0.63, and -0.58, respectively). Antibacterial properties of AgNP were evaluated against Bacillus subtilis, Klebsiella pneumoniae, and Salmonella typhi using the agar disk diffusion and minimum inhibitory concentration protocol. AgNP tested at 50 ppm evoked growth inhibition zones larger than 5 mm in all tested bacteria. Overall, the chance to use S. muticum-synthesized AgNP for control of mosquito vectors seems promising since they are effective at low doses and may constitute an advantageous alternative to build newer and safer mosquito control tools. This is the first

  16. Design and syntheses of MMP inhibitors and photosensitive lipid nanoparticle formulations for drug delivery

    Science.gov (United States)

    Subramaniam, Rajesh

    Drug administration without any compromise to the quality of life and lifespan is the ideal goal for disease management. The molecular mechanisms of several pathologies have shown that site-specific delivery of target-specific drugs seems to be a promising avenue to achieve this goal. This thesis describes the initial steps that we have taken toward that goal. Matrix metalloproteinases (MMPs) are a family of about 23 isozymes in humans that were actively targeted for treating a multitude of pathologies. Clinical studies carried out on cancer patients have revealed the complexity of the working of this enzyme family and necessitated the development of isozyme-specific MMP inhibitors. Our studies toward the development of isozyme-specific inhibitors have resulted in the development of several inhibitors that seem to be selective toward some MMP isozymes. Our understanding on the molecular mechanism that confers this selectivity is documented in this thesis. Another aspect of discussion in the thesis is the development of photosensitive liposomes for drug delivery that could be triggered to release the drug by irradiation with light of appropriate wavelength. Development of such delivery vehicles, in principle, would confer external spatiotemporal control on drug delivery. This could potentially lead to better disease management by minimizing side effects and enhancing patient compatibility. The thesis discusses our attempts toward the development of photosensitive liposomes. These liposomes incorporated a photosensitive lipid (PSL) that would be cleaved upon irradiation with UV light, causing liposomal destabilization and release of the enclosed drug. The discussion includes: (i) the syntheses of the PSLs, (ii) formulation of the photosensitive liposomes that contained a model drug, (iii) light-mediated release of the drug and (iv) the mechanism of photocleavage of the PSL that leads to content release from liposomes. The thesis concludes with suggestions toward the

  17. Surface plasmon enhanced near-UV emission in monodispersed ZnO:Ag core-shell type nanoparticles synthesized by a wet chemical method

    Science.gov (United States)

    Jadhav, J.; Biswas, S.

    2016-03-01

    Monodispersed core-shell type ZnO:Ag nanoparticles were synthesized by a wet chemical method and their salient properties were reported. The synthesis technique explores a facile route following a chemical reaction between aqueous solutions of poly-vinyl alcohol (PVA), sucrose and Zn2+ salt. The Zn2+-PVA-sucrose polymer precursor powders so obtained after the reaction was further explored for the synthesis of ZnO:Ag nanoparticles. The key part of the process lies in the use of polymer encapsulated ZnO nanoparticles as templates to obtain the ZnO core-Ag shell type nanostructures. Structural, morphological and optical properties of the derived ZnO:Ag core-shell nanoparticles were evaluated with X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high resolution transmission electron microscope (HRTEM), Raman spectroscopy, UV-visible diffuse reflectance spectroscopy, and photoluminescence (PL) spectroscopy. Microstructural analysis revealed monodispersed platelet shaped ZnO nanoparticles with a thin layer of Ag coating on the surface. The surface modified ZnO nanoparticles show colossal enhancement in their near-UV emission characteristics, primarily due to the efficient excitation of surface plasmons and excellent semiconductor-metal interfacing in the ZnO:Ag nanoparticles.

  18. Influence of catalytic gold and silver metal nanoparticles on structural, optical, and vibrational properties of silicon nanowires synthesized by metal-assisted chemical etching

    Science.gov (United States)

    Dawood, M. K.; Tripathy, S.; Dolmanan, S. B.; Ng, T. H.; Tan, H.; Lam, J.

    2012-10-01

    We report on the structural and vibrational characterization of silicon (Si) nanowire arrays synthesized by metal-assisted chemical etching (MACE) of Si deposited with metal nanoparticles. Gold (Au) and silver (Ag) metal nanoparticles were synthesized by glancing angle deposition, and MACE was performed in a mixture of H2O2 and HF solution. We studied the structural differences between Au and Ag-etched Si nanowires. The morphology of the synthesized nanowires was characterized by scanning electron microscopy and transmission electron microscopy. The optical and vibrational properties of the Si nanostructures were studied by photoluminescence and Raman spectroscopy using three different excitation sources (UV, visible, and near-infrared) and are correlated to their microstructures. The structural differences between Au-etched and Ag-etched nanowires are due to the higher degree of hole injection by the Au nanoparticle and diffusion into the Si nanowires, causing enhanced Si etching by HF on the nanowire surface. Au-etched nanowires were observed to be mesoporous throughout the nanowire while Ag-etched nanowires consisted of a thin porous layer around the crystalline core. In addition, the surface-enhanced resonant Raman scattering observed is attributed to the presence of the sunken metal nanoparticles. Such Si nanostructures may be useful for a wide range of applications such as photovoltaic and biological and chemical sensing.

  19. Enhanced ultraviolet photocatalytic activity of Ag/ZnO nanoparticles synthesized by modified polymer-network gel method

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Y. H.; Xu, M., E-mail: hsuming-2001@aliyun.com [Southwest University for Nationalities, Key Laboratory of Information Materials of Sichuan Province, School of Electrical and Information Engineering (China); Xu, L. X. [Nanyang Technological University, Plasma Sources and Applications Center, NIE (Singapore); Zhang, C. L.; Zhang, Q. P.; Xu, X. N. [Southwest University for Nationalities, Key Laboratory of Information Materials of Sichuan Province, School of Electrical and Information Engineering (China); Xu, S. [Nanyang Technological University, Plasma Sources and Applications Center, NIE (Singapore); Ostrikov, K., E-mail: kostya.ostrikov@qut.edu.au [Queensland University of Technology, Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering (Australia)

    2015-09-15

    Ag/ZnO nanoparticle (NP) heterostructures are synthesized through a modified polymer-network gel method in which glucose is added to the precursor solution to prevent the gel from drastically shrinking during drying of the aqueous solution. Structural and optical properties of the samples are characterized by a range of techniques including XRD, SEM, TEM, XPS, UV–Vis, and PL. The high-quality Ag-ZnO heterostructure is evidenced clearly by high-resolution TEM. The Ag/ZnO heterostructure nanocomposites exhibit a higher photocatalytic activity in the degradation of methyl orange than pure ZnO. Especially, Ag/ZnO NP heterostructures with the Ag/Zn molar ratio of 5:95 (sample ZA-5) show the highest degradation efficiency, which is 11 times higher compared with pure ZnO. The photoluminescence properties of the heterostructures and O defect states are studied to well explain the observed photocatalytic effects. ZA-5 also exhibits competitive photocatalytic activity for the degradation of other pollutant dyes such as Methylene blue and Rhodamine B compared with the recently reported techniques, while showing excellent catalyst photostability as well as offering simplicity and reliability.

  20. Aristolochia indica green-synthesized silver nanoparticles: A sustainable control tool against the malaria vector Anopheles stephensi?

    Science.gov (United States)

    Murugan, Kadarkarai; Labeeba, Mohammed Aamina; Panneerselvam, Chellasamy; Dinesh, Devakumar; Suresh, Udaiyan; Subramaniam, Jayapal; Madhiyazhagan, Pari; Hwang, Jiang-Shiou; Wang, Lan; Nicoletti, Marcello; Benelli, Giovanni

    2015-10-01

    Malaria is a life-threatening disease caused by parasites transmitted to people and animals through the bites of infected mosquitoes. We biosynthesized silver nanoparticles (AgNP) using Aristolochia indica extract as reducing and stabilizing agent. AgNP were characterized by UV-vis spectroscopy, FTIR, SEM, EDX and XRD. In laboratory, LC50 of A. indica extract against Anopheles stephensi ranged from 262.66 (larvae I) to 565.02 ppm (pupae). LC50 of AgNP against A. stephensi ranged from 3.94 (larvae I) to 15.65 ppm (pupae). In the field, the application of A. indica extract and AgNP (10 × LC50) leads to 100% larval reduction after 72 h. In laboratory, 24-h predation efficiency of Diplonychus indicus against A. stephensi larvae was 33% (larvae II) and 57% (larvae III). In AgNP-contaminated environment (1 ppm), it was 45.5% (larvae II) and 71.75% (larvae III). Overall, A. indica-synthesized AgNP may be considered as newer and safer control tools against Anopheles vectors.

  1. Green synthesized gold nanoparticles decorated graphene oxide for sensitive determination of chloramphenicol in milk, powdered milk, honey and eye drops.

    Science.gov (United States)

    Karthik, R; Govindasamy, Mani; Chen, Shen-Ming; Mani, Veerappan; Lou, Bih-Show; Devasenathipathy, Rajkumar; Hou, Yu-Shen; Elangovan, A

    2016-08-01

    A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV-Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5-2.95μM, low detection limit of 0.25μM and high sensitivity of 3.81μAμM(-1)cm(-2). The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures. PMID:27153217

  2. Optical and magnetic properties of La1-xGaxFeO3 nanoparticles synthesized by polymerization complex method

    Science.gov (United States)

    Hunpratub, Sitchai; Karaphun, Attaphol; Phokha, Sumalin; Swatsitang, Ekaphan

    2016-09-01

    La1-xGaxFeO3 (x = 0.0, 0.1, 0.2, 0.3 and 0.4) nanoparticles were synthesized by polymerization complex method. X-ray diffraction (XRD) results reveal a pure orthorhombic phase structure. Increasing of Ga content, resulting in the decrease of average crystallite sizes calculated by XRD from 58.4 ± 5.9 to 13.4 ± 4.3 nm and the average particle sizes estimated by transmission electron microscope (TEM) images from 70.2 ± 4.5 to 21.4 ± 8.5 nm. The optical band gaps determined by UV-vis spectra showed a redshift from 2.145 to 1.954 eV that originates from surface effect caused by Ga substitution. The magnetic properties were investigated using a vibrating sample magnetometer (VSM). The room temperature hysteresis loops of La1-xGaxFeO3 nanopowders indicate the antiferromagnetic behavior of pure sample and all doped samples of ferromagnetic behavior with the enhancement of coercive field (Hc), remanence (Mr) and magnetization (M) due to the more disordering spins induced at the surface of particle. It is evident from field cool (FC) measurement of La0.6Ga0.4FeO3 sample that the Curie temperature (Tc) is above 350 K.

  3. Facile method to synthesize magnetic iron oxides/TiO2 hybrid nanoparticles and their photodegradation application of methylene blue

    Directory of Open Access Journals (Sweden)

    Wu Wei

    2011-01-01

    Full Text Available Abstract Many methods have been reported to improving the photocatalytic efficiency of organic pollutant and their reliable applications. In this work, we propose a facile pathway to prepare three different types of magnetic iron oxides/TiO2 hybrid nanoparticles (NPs by seed-mediated method. The hybrid NPs are composed of spindle, hollow, and ultrafine iron oxide NPs as seeds and 3-aminopropyltriethyloxysilane as linker between the magnetic cores and TiO2 layers, respectively. The composite structure and the presence of the iron oxide and titania phase have been confirmed by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectra. The hybrid NPs show good magnetic response, which can get together under an external applied magnetic field and hence they should become promising magnetic recovery catalysts (MRCs. Photocatalytic ability examination of the magnetic hybrid NPs was carried out in methylene blue (MB solutions illuminated under Hg light in a photochemical reactor. About 50% to 60% of MB was decomposed in 90 min in the presence of magnetic hybrid NPs. The synthesized magnetic hybrid NPs display high photocatalytic efficiency and will find recoverable potential applications in cleaning polluted water with the help of magnetic separation.

  4. Green synthesized gold nanoparticles decorated graphene oxide for sensitive determination of chloramphenicol in milk, powdered milk, honey and eye drops.

    Science.gov (United States)

    Karthik, R; Govindasamy, Mani; Chen, Shen-Ming; Mani, Veerappan; Lou, Bih-Show; Devasenathipathy, Rajkumar; Hou, Yu-Shen; Elangovan, A

    2016-08-01

    A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV-Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5-2.95μM, low detection limit of 0.25μM and high sensitivity of 3.81μAμM(-1)cm(-2). The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures.

  5. Effects of precursor on the morphology and size of ZrO{sub 2} nanoparticles, synthesized by sol-gel method in non-aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Mohammed Rafiq Hussain; Al-Wassil, Abdulaziz Ibrahim; Mahfouz, Refaat Mohamad [King Saud University, Riyadh (Saudi Arabia). Department of Chemistry, College of Science; Al-Otaibi, Abdullah Mohmmed [King Abdulaziz City for Science and Technology (Saudi Arabia). The NationalProgram for Advanced Materials and Building Systems

    2012-11-15

    Pure zirconium oxide (ZrO{sub 2}) nanoparticles with diameters 10-25 nm were synthesized from ZrOCl{sub 2}.8H{sub 2}O and Zr(SO{sub 4})2.H{sub 2}O with benzyl alcohol as non-aqueous solvent medium using sol-gel method. Sodium lauryl sulfate was added as surfactants to control the particle size. The synthesized ZrO{sub 2} nanoparticles have a mixture of tetragonal and monoclinic structure. The XRD showed the purity of obtained ZrO{sub 2} nanoparticles with tetragonal and monoclinic phase and the crystallite size for ZrOCl{sub 2}.8H{sub 2}O precursor was estimated to be 18.1 nm and that from Zr(SO{sub 4})2.H{sub 2}O was 9.7 nm. The transmission electron microscopy and scanning electron microscopic studies also shows different sizes of nanoparticles and different morphology depending on the precursor used for the synthesis of ZrO{sub 2} nanoparticles. (author)

  6. Formic acid electro-oxidation on carbon supported Pd{sub x}Pt{sub 1-x} (0 {>=} x {>=} 1) nanoparticles synthesized via modified polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Baranova, Elena A., E-mail: elena.baranova@uottawa.c [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur St., Ottawa, ON, K1N 6N5 (Canada); Miles, Neil [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur St., Ottawa, ON, K1N 6N5 (Canada); Mercier, Patrick H.J.; Le Page, Yvon; Patarachao, Bussaraporn [Institute for Chemical Process and Environmental Technology, National Research Council Canada, 1200 Montreal Rd., Ottawa, ON, K1A 0R6 (Canada)

    2010-11-30

    Carbon supported nanoparticle catalysts of Pd{sub x}Pt{sub 1-x} (0 {>=} x {>=} 1) were synthesized using a modified polyol method and poly(N-vinyl-2-pyrrolidone) (PVP) as a stabilizer. Resulting nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperommetry (CA) study for formic acid electro-oxidation. Surface composition of the synthesized nanoparticles found from XPS revealed the Pt surface segregation even for the Pd-rich compositions. It is suggested that the surface segregation behavior in PdPt nanoparticles supported on carbon may be influenced, in addition to the difference in Pd and Pt surface energies, by particle size and particle interaction with the support. According to CA, the carbon supported Pd nanoparticles show the highest initial activity towards formic acid electro-oxidation at the potential of 0.3 V (RHE), due to the promotion of the direct dehydrogenation mechanism. However its stability is quite poor resulting in the fast deactivation of the Pd surface. Addition of Pt considerably improves the steady-state activity of Pd in 12 h CA experiment. CA measurements show that the most active catalyst is Pd{sub 0.5}Pt{sub 0.5} of 4 nm size, which displays narrow size distribution and Pd to Pt surface atomic ratio of 27-73.

  7. Antiplasmodial activity of eco-friendly synthesized palladium nanoparticles using Eclipta prostrata extract against Plasmodium berghei in Swiss albino mice.

    Science.gov (United States)

    Rajakumar, Govindasamy; Rahuman, Abdul Abdul; Chung, Ill-Min; Kirthi, Arivarasan Vishnu; Marimuthu, Sampath; Anbarasan, Karunanithi

    2015-04-01

    Malaria is an infectious disease caused by the Plasmodium parasite that continues to be a health issue for humans. It is one of the most common pathogenic factors of morbidity and mortality. Palladium nanoparticles (Pd NPs) have been used as target antimicrobial compounds, as a catalyst to manufacture pharmaceuticals, degrade harmful environmental pollutants, and as sensors for the detection of various analyses. The aim of this study was to investigate the antiplasmodial activity of synthesized Pd NPs by using leaf aqueous extract of Eclipta prostrata against Plasmodium berghei in Swiss albino mice. The synthesized Pd NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Scanning electron microscopy (SEM) with Energy dispersive X-ray spectroscopy (EDX), and High-resolution transmission electron microscope (HRTEM) with the Selected area (electron) diffraction (SAED). The XRD peaks appeared at 35.61°, 44.27°, 56.40°, and 74.51°, which correspond to (111), (200), (220), and (311) planes for palladium, respectively. The FTIR spectra that were carried out to identify the potential biomolecule of synthesized Pd NPs showed the peaks at 3361, 1540, 1399, 1257, 1049, and 659 in the region of 4000-500 cm(-1). The SEM images showed aggregation of NPs with an average size of 63 ± 1.4. The HRTEM images of the precipitated solid phase obtained after termination of the reaction of E. prostrata aqueous leaf extract were in the range from 18 to 64 nm with an average size of 27 ± 1.3 nm. The in vivo antiplasmodial assay was carried out as per Peters' 4-day suppressive test, and the synthesized Pd NP-treated mice group showed reduction of parasitemia by 78.13% with an inhibitory concentration (IC)50 value of 16.44 mg/kg/body weight. The growth inhibition of E. prostrata aqueous leaf extract, palladium acetate, and synthesized Pd NPs showed the IC20, IC50, and IC90 values of 1.90, 10.29, and 64.11; 4.49, 9.84, and 23.04; and 4.34, 8

  8. Co-deposition of Synthesized ZnO Nanoparticles into Ni-P Matrix Using Electroless Technique and Their Corrosion Study

    Science.gov (United States)

    Sharma, Sarika; Sharma, Sulaxna; Sharma, Awanish; Agarwala, Vijaya

    2016-10-01

    In the present study, Ni-P-ZnO nanocomposite coating was developed on the surface of mild steel substrate by electroless technique. The second phase ZnO nanoparticles were synthesized by autocombustion method, to incorporate into the Ni-P matrix. 10 g/L of ZnO nanoparticles were added to the Ni-P alkaline bath for co-deposition, and the electroless bath was reduced by sodium hypophosphite. The heat treatment of the as-prepared Ni-P/Ni-P-ZnO coatings was carried out at 400 °C in argon (99.9%) atmosphere for 1 h. The as-prepared and heat-treated Ni-P/Ni-P-ZnO coatings and ZnO nanoparticles were analyzed for surface morphology, elemental composition, phase analysis and particle size distribution using field emission scanning electron microscopy (FESEM), energy-dispersive analysis of x-rays (EDAX), transmission electron microscopy (TEM), powder x-ray diffraction analysis. To determine the calcinations temperature of ZnO powder, differential scanning calorimetry was also carried out. TEM analysis of the synthesized ZnO nanoparticles was also carried out, and from the micrographs a spherical shape of ~40 nm size range is observed for the ZnO nanoparticles. The corrosion properties of the coatings were carried out in a 3.5 wt.% NaCl solution by electrochemical polarization test. The dispersion of ZnO nanoparticles into the coating is determined by FESEM. Atomic force microscopy was used to investigate the change in the surface topography of the coatings before and after exposure in the test environment. A uniform distribution of ZnO nanoparticles into the Ni-P matrix is confirmed by the FESEM-EDAX results. Electrochemical test results suggest that Ni-P-ZnO shows better corrosion resistance as compared to plain Ni-P coating.

  9. Co-deposition of Synthesized ZnO Nanoparticles into Ni-P Matrix Using Electroless Technique and Their Corrosion Study

    Science.gov (United States)

    Sharma, Sarika; Sharma, Sulaxna; Sharma, Awanish; Agarwala, Vijaya

    2016-08-01

    In the present study, Ni-P-ZnO nanocomposite coating was developed on the surface of mild steel substrate by electroless technique. The second phase ZnO nanoparticles were synthesized by autocombustion method, to incorporate into the Ni-P matrix. 10 g/L of ZnO nanoparticles were added to the Ni-P alkaline bath for co-deposition, and the electroless bath was reduced by sodium hypophosphite. The heat treatment of the as-prepared Ni-P/Ni-P-ZnO coatings was carried out at 400 °C in argon (99.9%) atmosphere for 1 h. The as-prepared and heat-treated Ni-P/Ni-P-ZnO coatings and ZnO nanoparticles were analyzed for surface morphology, elemental composition, phase analysis and particle size distribution using field emission scanning electron microscopy (FESEM), energy-dispersive analysis of x-rays (EDAX), transmission electron microscopy (TEM), powder x-ray diffraction analysis. To determine the calcinations temperature of ZnO powder, differential scanning calorimetry was also carried out. TEM analysis of the synthesized ZnO nanoparticles was also carried out, and from the micrographs a spherical shape of ~40 nm size range is observed for the ZnO nanoparticles. The corrosion properties of the coatings were carried out in a 3.5 wt.% NaCl solution by electrochemical polarization test. The dispersion of ZnO nanoparticles into the coating is determined by FESEM. Atomic force microscopy was used to investigate the change in the surface topography of the coatings before and after exposure in the test environment. A uniform distribution of ZnO nanoparticles into the Ni-P matrix is confirmed by the FESEM-EDAX results. Electrochemical test results suggest that Ni-P-ZnO shows better corrosion resistance as compared to plain Ni-P coating.

  10. Colloidal gold nanoparticles. Synthesis, characterization and effect in polymer/fullerene solar cells; Kolloidale Goldnanopartikel. Synthese, Charakterisierung und Wirkung in Polymer/Fulleren-Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Topp, Katja

    2011-06-08

    It has been reported in the literature that the efficiency of polymer/fullerene solar cells has been improved by the incorporation of Au nanoparticles. The improvement was attributed to an enhanced electrical conductivity of the active layer and to an enhanced light absorption due to the plasmon resonance of the Au nanoparticles. In this work colloidal Au nanoparticles coated with different stabilizing ligands were synthesized and characterized. Then the impact of their incorporation into P3HT/PCBM solar cells was studied. On the one hand the Au nanoparticles were incorporated into the bulk heterojunction active layer, otherwise they were deposited as an interlayer in the device set-up. No improvement of the solar cell efficiency could be observed neither for the incorporation of Au nanoparticles with isolating ligand shell nor for those with direct contact to the photoactive molecules. The efficiency even dropped, the more the higher the concentration of the Au nanoparticles was. Possible reasons are pointed out on the basis of detailed photophysical and structural investigations.

  11. Consequence of pH variation on the dielectric properties of Cr-doped lithium ferrite nanoparticles synthesized by the sol–gel method

    International Nuclear Information System (INIS)

    Highlights: • Cr-doped Li-ferrite nanoparticles have been synthesized at different pH values via sol–gel method. • Dielectric properties strongly depend on the pH value. • Samples synthesized at pH 3.5 exhibits the highest dielectric constant, on the order of ∼107. - Abstract: Nanocrystalline Cr-doped lithium ferrites have been synthesized at different pH values through sol–gel process. Dielectric properties of the synthesized samples were studied via impedance measurements in the frequency range of 100 Hz–7 MHz at room temperature. It was found that the dielectric properties strongly depended on the pH value, and the sample synthesized at pH 3.5 exhibited the highest dielectric constant, on the order of ∼107. In contrast, the sample synthesized at pH 11.5 exhibited the lowest dielectric constant. The occurrence of a peak in the dielectric loss spectra was found to be pH dependent, whereas the AC conductivity increased with frequency and was the highest in the sample synthesized at pH 3.5. The impedance spectroscopy and modulus formulism were also employed to investigate the charge transfer and relaxation dynamic properties. Consequently, dielectric properties of the samples were easily tuned by varying the pH during the synthesis process

  12. Controlling the morphology and properties of solvothermal synthesized Cu{sub 2}ZnSnS{sub 4} nanoparticles by solvent type

    Energy Technology Data Exchange (ETDEWEB)

    Bahramzadeh, Saeid [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Abdizadeh, Hossein [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, University of Tehran, Tehran (Iran, Islamic Republic of); Golobostanfard, Mohammad Reza, E-mail: Bostanfr@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

    2015-09-05

    Highlights: • CZTS nanoparticles are fabricated by solvothermal method with different solvents. • Different morphologies are achieved by EDA, TETA, EG, and OA solvents. • Property and chelating ability of the solvents have a key role on nanoparticles formation. • TETA and OA are strongly recommended for solar cell applications. - Abstract: The copper–zinc–tin sulfide Cu{sub 2}ZnSnS{sub 4} (CZTS) semiconductors are recently considered as one of the favorable materials for application as absorber layers in solar cells due to their appropriate direct band gap energy and high optical absorption coefficient. In this study, the effect of solvent type on properties of solvothermal synthesized CZTS nanoparticles has been investigated. Ethylenediamine (EDA), triethylenetetramine (TETA), ethylene glycol (EG), and oleic acid (OA) have been used as the solvent. X-ray diffraction technique and Raman spectroscopy confirmed the formation of crystalline CZTS nanoparticles with kesterite crystal structure in these solvents with the exception of EDA, which forms wurtzite crystal structure. Morphological characterizations show that several distinct morphologies including spherical (70–160 nm), nanoplates (∼45 nm thickness and more than 1 μm length), peculiar flower-like particles (with diameter of ∼0.4–1.5 μm), truncated hexagonal disks, irregular particles, and hexagonal microdisks are obtained by varying the solvent type. Optical studies revealed broad absorption of the CZTS particles in the visible region. Compared with other solvents, OA synthesized CZTS particles show higher absorption in the visible region. However, CZTS nanoparticles synthesized by TETA solvent show the most appropriate properties for application as an absorber materials in solar cells due to high crystallinity, low impurity phases, suitable size, and proper band gap energy.

  13. Effect of pH variation on the stability and structural properties of In(OH)3 nanoparticles synthesized by co-precipitation method

    Science.gov (United States)

    Goh, Kian Wei; Johan, Mohd Rafie; Wong, Yew Hoong

    2016-10-01

    Indium hydroxide (In(OH)3) nanoparticles were synthesized at various pH values (8-11) by co-precipitation method. Its properties were characterized by X-ray diffractometer, Fourier transform infrared spectroscopy, Raman spectroscopy and transmission electron microscope. The electrostatic stability of nanoparticles is carried out through zeta potential measurement. The crystallite size of nanoparticles calculated by Scherrer equation has similar trend with the values obtained from William-Hall plot. TEM images show that the particles size is within the range of 11.76-20.76 nm. The maximum zeta potential is 3.68 mV associated with the smallest particle size distribution of 92.6 nm occurred at pH 10. Our work clearly confirms the crystallite size, stability and the morphology of In(OH)3 NPs are strongly depending on the pH of precursor solution.

  14. A novel hydrothermal approach for synthesizing α-Fe2O3, γ-Fe2O3 and Fe3O4 mesoporous magnetic nanoparticles

    International Nuclear Information System (INIS)

    A novel method to synthesize the three phases of iron oxide nanoparticles (hematite, maghemite and magnetite) using the same non-toxic inorganic precursors via a water–organic interface under the low temperature hydrothermal conditions is reported. The synthesized particles are characterized by Powder X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). The Brunauer–Emmett–Teller (BET) results reveal the mesoporous nature of the particles. The magnetic properties of the nanoparticles are studied by Vibrating Sample Magnetometer (VSM) at various low temperatures and also at room temperature. The XRD peaks corresponding to each sample clearly depict the presence of the respective phase of the as-prepared magnetic nanoparticles. The nanoparticles of maghemite and magnetite have saturation magnetization of 58.56 and 40.30 emu/g respectively at room temperature, whereas the particles of hematite possess very low saturation magnetization value of 1.89 emu/g. Further, the magnetization is studied at four different temperatures and the zero field cooled (ZFC) and field cooled (FC) magnetization are reported. - Graphical abstract: Display Omitted - Highlights: • Hematite, maghemite and magnetite are obtained under hydrothermal synthesis. • α-Fe2O3, γ-Fe2O3 and Fe3O4 prepared are mesoporous and nearly monodisperse. • Near superparamagnetism is observed at room temperature for maghemite and magnetite

  15. Effect of Fe-doping on the structural, morphological and optical properties of ZnO nanoparticles synthesized by solution combustion process

    Science.gov (United States)

    Silambarasan, M.; Saravanan, S.; Soga, T.

    2015-07-01

    The effect of Fe-doping on the structural, morphological and optical properties of ZnO nanoparticles synthesized by simple solution combustion process are reported. The powder XRD pattern indicates that the Fe-doped ZnO samples exhibit primary and secondary phases. The primary phase indicates the hexagonal wurtzite structure with the average crystalline size of around 25-50 nm and the secondary phase is associated with the face centered cubic structure of magnetite iron oxide. The elemental composition of pure and Fe-doped samples are evaluvated by EDX. The results of FE-SEM and HR-TEM cleary show that particles morphology have changed with respect to the incorporation of doping agent and particles are in aggregating nature. The vibrational properties of the synthesized ZnO nanoparticles are investigated by Raman scattering technique and it exhibits that the influence of Fe-doping significantly modify the lattice vibrational characteristics in ZnO sites. The optical properties of the Fe-doped ZnO nanoparticles are carried out by UV-vis absorption and PL spectra. The results of PL spectra show the near-band edge related emission as well as strong blue emissions in the Fe-doped ZnO nanoparticles.

  16. Superparamagnetism and metamagnetic transition in Fe3O4 nanoparticles synthesized via co-precipitation method at different pH

    International Nuclear Information System (INIS)

    In the present work, Fe3O4 nanoparticles have been synthesized via low temperature co-precipitation method at different pH (7.0, 11.0 and 12.4) with the aim to study the variation of pH on the structural, optical and magnetic properties of samples. Further, the sample synthesized at pH ~12.4 has been annealed at 230 °C for 10 h to study the effect of annealing on structural, optical and magnetic properties. X-ray diffraction (XRD) results reveal the formation of pure spinel phase with the space group Fd-3m. Further, XRD, FESEM and TEM results confirm the nanocrystalline nature of the as synthesized samples, and the particle size of the samples decreases as the pH increases and increases after annealing at 230 °C. FTIR analysis indicates that the sample synthesized at pH ~12.4 and the same sample annealed at 230 °C are pure spinel Fe3O4, whereas the samples synthesized at pH ~7.0 and 11.0 have small content of α-Fe2O3. The optical measurements of the as synthesized samples show two band gaps in all synthesized samples. Field dependent magnetization measurements (M–H) reveal superparamagnetic nature of all the synthesized samples at room temperature and ferromagnetic behavior at low temperature (~5 K). Furthermore, M–H plots measured at 5 K show presence of metamagnetic transition in all samples. The metamagnetic transition along with ferromagnetic behavior at low temperature in Fe3O4 nanoparticles are observed first time in the present work to the best of our knowledge. Further the value of magnetization decreases with decreasing particle size at both temperatures. The fitting of the field cooled (FC) temperature dependent magnetization (M–T) measurements data with modified Bloch-spin wave model with additional surface disorder term and mixed magnetic phases indicates surface spin disorder and mixed magnetic phases in the as synthesized samples, which may be the possible reason for the existence of metamagnetic transition in the samples. The correlation

  17. Influence of aging time of oleate precursor on the magnetic relaxation of cobalt ferrite nanoparticles synthesized by the thermal decomposition method

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Adriana P.; Polo-Corrales, Liliana [Department of Chemical Engineering, University of Puerto Rico, Mayagueez, Puerto Rico, PR 00681-9000 (United States); Chavez, Ermides; Cabarcas-Bolivar, Jari [Department of Physics, University of Puerto Rico, Mayagueez, Puerto Rico, PR 00681-9000 (United States); Uwakweh, Oswald N.C. [Department of General Engineering, University of Puerto Rico, Mayagueez, Puerto Rico, PR 00681-9000 (United States); Rinaldi, Carlos, E-mail: crinaldi@uprm.edu [Department of Chemical Engineering, University of Puerto Rico, Mayagueez, Puerto Rico, PR 00681-9000 (United States)

    2013-02-15

    Cobalt ferrite nanoparticles are of interest because of their room temperature coercivity and high magnetic anisotropy constant, which make them attractive in applications such as sensors based on the Brownian relaxation mechanism and probes to determine the mechanical properties of complex fluids at the nanoscale. These nanoparticles can be synthesized with a narrow size distribution by the thermal decomposition of an iron-cobalt oleate precursor in a high boiling point solvent. We studied the influence of aging time of the iron-cobalt oleate precursor on the structure, chemical composition, size, and magnetic relaxation of cobalt ferrite nanoparticles synthesized by the thermal decomposition method. The structure and thermal behavior of the iron-cobalt oleate was studied during the aging process. Infrared spectra indicated a shift in the coordination state of the oleate and iron/cobalt ions from bidentate to bridging coordination. Aging seemed to influence the thermal decomposition of the iron-cobalt oleate as determined from thermogravimmetric analysis and differential scanning calorimetry, where shifts in the temperatures corresponding to decomposition events and a narrowing of the endotherms associated with these events were observed. Aging promoted formation of the spinel crystal structure, as determined from X-ray diffraction, and influenced the nanoparticle magnetic properties, resulting in an increase in blocking temperature and magnetocrystalline anisotropy. Mossbauer spectra also indicated changes in the magnetic properties resulting from aging of the precursor oleate. Although all samples exhibited some degree of Brownian relaxation, as determined from complex susceptibility measurements in a liquid medium, aging of the iron-cobalt oleate precursor resulted in crossing of the in-phase {chi} Prime and out-of-phase {chi} Double-Prime components of the complex susceptibility at the frequency of the Brownian magnetic relaxation peak, as expected for

  18. Larvicidal activity of green synthesized silver nanoparticles using bark aqueous extract of Ficus racemosa against Culex quinquefasciatus andCulex gelidus

    Institute of Scientific and Technical Information of China (English)

    Kanayairam Velayutham; Chinnadurai Siva; Abdul Abdul Rahuman; Govindasamy Rajakumar; Selvaraj Mohana Roopan; Gandhi Elango; Chinnaperumal Kamaraj; Sampath Marimuthu; Thirunavukkarasu Santhoshkumar; Moorthy Iyappan

    2013-01-01

    Objective:To investigate the larvicidal activity of synthesized silver nanoparticles (AgNPs) utilizing aqueous bark extract ofFicus racemosa (F. racemosa) was tested against fourth instar larvae of filariasis vector,Culex quinquefasciatus (Cx. quinquefasciatus) and japanese encephalitis vectors,Culex gelidus (Cx. gelidus).Methods:The synthesizedAgNPs was characterized byUV-vis spectrum,X-ray diffraction (XRD),Scanning electron microscopy (SEM) andFourier transform infrared (FTIR).The larvicidal activities were assessed for24 h against the larvae ofCx. quinquefasciatus andCx. gelidus with varying concentrations of aqueous bark extract ofF. racemosa and synthesizedAgNPs.LC50 andr2 values were calculated.Results:The maximum efficacy was observed in crude aqueous extract ofF. racemosa against the larvae of Cx. quinquefasciatus andCx. gelidus (LC50=67.72 and63.70 mg/L;r2=0.995 and0.985) and the synthesizedAgNPs (LC50=12.00 and11.21 mg/L;r2=0.997 and0.990), respectively.SynthesizedAg NPs showed theXRD peaks at2θ values of27.61,29.60,35.48,43.48 and79.68were identified as (210), (121), (220), (200) and (311) reflections, respectively.TheFTIR spectra ofAgNPs exhibited prominent peaks at3425,2878,1627 and1382 in the region500-3000 cm-1.The peaks correspond to the presence of a stretching vibration of (NH)C=O group.SEM analysis showed shape in cylindrical, uniform and rod with the average size of250.60 nm.Conclusions:The biosynthesis of silver nanoparticles using bark aqueous extract ofF. racemosa and its larvicidal activity against the larvae of disease spreading vectors.The maximum larvicidal efficacy was observed in the synthesizedAgNPs.

  19. Highly magnetic Fe{sub 2}O{sub 3} nanoparticles synthesized by laser pyrolysis used for biological and heat transfer applications

    Energy Technology Data Exchange (ETDEWEB)

    Dumitrache, F., E-mail: dumitracheflorian@yahoo.com [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania); “Politehnica” University of Bucharest, Physics Department, Independentei 313, Bucharest (Romania); Morjan, I. [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania); Fleaca, C. [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania); “Politehnica” University of Bucharest, Physics Department, Independentei 313, Bucharest (Romania); Badoi, A. [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania); Manda, G.; Pop, S.; Marta, D.S. [“Victor Babes” National Institute of Pathology, Independentei 99-101, Bucharest (Romania); Huminic, G.; Huminic, A. [“Trasilvania” University, 29 Eroilor Blv., 500036, Brasov (Romania); Vekas, L.; Daia, C. [Romanian Academy – Timisoara branch, 24 Mihai Viteazul Blv., Timisoara (Romania); Marinica, O. [“Politehnica” University of Timisoara – Research Center for Engineering of Systems with Complex Fluids, 1 Mihai Viteazul Blv., Timisoara (Romania); Luculescu, C.; Niculescu, A.-M. [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania)

    2015-05-01

    Highlights: • Laser pyrolysis technique was employed for gamma iron oxide nanoparticles synthesis. • Hydrophobicity was induced by higher synthesis temperature due to C{sub 2}H{sub 4} decomposition. • They show or ferro or superpamagnetic behavior and 70 emu/g saturation magnetization. • Nanoparticles (20 g/l)/L-DOPA aqueous suspensions have enhanced thermal conductivity. • The suspensions show no cytotoxic effects on human tumor or normal mouse immune cells. - Abstract: γFe{sub 2}O{sub 3}-based nanoparticles were synthesized by laser pyrolysis using various optimized Fe(CO){sub 5}, O{sub 2} and C{sub 2}H{sub 4} flow ratios in the reactive mixture, and different laser power values. Depending on particular conditions, two different iron oxide-based nanoparticles (MNPs) were synthesized, with a hydrophilic or hydrophobic behavior, both presenting a high magnetization saturation (around 70 emu/g). TEM, EDX, XRD and magnetic analyses were performed for a comprehensive characterization. The raw powders were successfully dispersed in aqueous media using L-DOPA as stabilizing agent. Dispersed samples, with or without stabilization agents, have been tested and DLS measurements proved their good stability, with the hydrodynamic diameter varying between 70 and 150 nm when the stabilizing agent was used. Thermal conductivity and viscosity tests on L-DOPA-functionalized MNPs suspensions reveal the increasing (up to 40%) of their thermal conductivity, accompanied by a viscosity increase of only 5%, validating them as thermal transfer fluids. Water-based nanoparticle dispersions and also those stabilized with L-DOPA proved a good biocompatibility, as demonstrated by a preliminary in vitro study on mouse primary leukocytes and human breast carcinoma cell line MCF-7; although ingested by the investigated cells, MNPs do not decrease cellular viability and proliferation.

  20. Polyvinyl polypyrrolidone attenuates genotoxicity of silver nanoparticles synthesized via green route, tested in Lathyrus sativus L. root bioassay.

    Science.gov (United States)

    Panda, Kamal K; Achary, V Mohan M; Phaomie, Ganngam; Sahu, Hrushi K; Parinandi, Narasimham L; Panda, Brahma B

    2016-08-01

    The silver nanoparticles (AgNPs) were synthesized extracellularly from silver nitrate (AgNO3) using kernel extract from ripe mango Mengifera indica L. under four different reaction conditions of the synthesis media such as the (i) absence of the reducing agent, trisodium citrate (AgNPI), (ii) presence of the reducing agent (AgNPII), (iii) presence of the cleansing agent, polyvinyl polypyrrolidone, PVPP (AgNPIII), and (iv) presence of the capping agent, polyvinyl pyrrolidone, PVP (AgNPIV). The synthesis of the AgNPs was monitored by UV-vis spectrophotometry. The AgNPs were characterised by the energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and small-angle X-ray scattering. Functional groups on the AgNPs were established by the Fourier transform infrared spectroscopy. The AgNPs (AgNPI, AgNPII, AgNPIII and AgNPIV) were spherical in shape with the diameters and size distribution-widths of 14.0±5.4, 19.2±6.6, 18.8±6.6 and 44.6±13.2nm, respectively. Genotoxicity of the AgNPs at concentrations ranging from 1 to 100mgL(-1) was determined by the Lathyrus sativus L. root bioassay and several endpoint assays including the generation of reactive oxygen species and cell death, lipid peroxidation, mitotic index, chromosome aberrations (CA), micronucleus formation (MN), and DNA damage as determined by the Comet assay. The dose-dependent induction of genotoxicity of the silver ion (Ag(+)) and AgNPs was in the order Ag(+)>AgNPII>AgNPI>AgNPIV>AgNPIII that corresponded with their relative potencies of induction of DNA damage and oxidative stress. Furthermore, the findings underscored the CA and MN endpoint-based genotoxicity assay which demonstrated the genotoxicity of AgNPs at concentrations (≤10mgL(-1)) lower than that (≥10mgL(-1)) tested in the Comet assay. This study demonstrated the protective action of PVPP against the genotoxicity of AgNPIII which was independent of the size of the AgNPs in the L. sativus L. root bioassay

  1. Dispersion and functionalization of nanoparticles synthesized by gas aggregation source: Opening new routes towards the fabrication of nanoparticles for bio-medicine

    Science.gov (United States)

    Oprea, B.; Martínez, L.; Román, E.; Vanea, E.; Simon, S.; Huttel, Y.

    2015-01-01

    The need to find new nanoparticles for biomedical applications is pushing the limits of the fabrication methods. New techniques with versatilities beyond the extended chemical routes can provide new insight in the field. In particular gas aggregation sources offer the possibility to fabricate nanoparticles with controlled size, composition and structure out of thermodynamics. In this context, the milestone is the optimization of the dispersion and functionalization processes of nanoparticles once fabricated by these routes as they are generated in the gas phase and deposited on substrates in vacuum or ultra-high vacuum conditions. In the present work we propose a fabrication route in ultra-high vacuum that is compatible with the subsequent dispersion and functionalization of nanoparticles in aqueous media and, that is more remarkable, in one single step. In particular, we will present the fabrication of nanoparticles with a sputter gas aggregation source, using a Fe50B50 target, and their further dispersion and functionalization with polyethileneglycol (PEG). A characterization of these nanoparticles is carried out before and after PEG functionalization. During functionalization, significant boron dissolution occurs, which facilitates nanoparticle dispersion in the aqueous solution. The use of different complementary techniques allows us to prove the PEG attachment onto the surface of the nanoparticles creating a shell to make them biocompatible. The result is the formation of nanoparticles with a structure mainly composed by a metallic Fe core and an iron oxide shell, surrounded by a second PEG shell dispersed in aqueous solution. Relaxivitiy measurements of these PEG functionalized nanoparticles assessed their effectiveness as contrast agents for Magnetic Resonance Imaging (MRI) analysis. Therefore, this new fabrication route is a reliable alternative for the synthesis of nanoparticles for biomedicine. PMID:26640032

  2. Effect of calcining temperature and time on the characteristics of Sb-doped SnO2 nanoparticles synthesized by the sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Xiaohua Zhong; Baoping Yang; Xiaoliang Zhang; Junhong Jia; Gewen Yi

    2012-01-01

    Spherical Sb-doped SnO2 (ATO) nanoparticles were synthesized by the sol-gel route,employing SnCl4·5H2O and SbCl3 as precursors in an ethanol solution.The influences of the calcining temperature and calcining time on the crystallite size,crystallinity,lattice parameters,lattice distortion ratio and the resistivity of the ATO nanoparticles were synthetically investigated.The results suggested that the ATO nanoparticles were crystallized in a tetragonal cassiterite structure of SnO2 with a highly (110)-plane-preferred orientation.The calcining temperature had a dominating effect on the crystallite size,crystallinity,lattice distortion ratios and resistivity of the ATO.As the calcining temperature increased,the average crystallite size increased,the crystallinity was promoted accompanied by a decrease in the lattice distortion ratio and a corresponding decrease in the resistivity of the ATO.X-ray diffraction (XRD) and Fourier transform infrared spectrophotometer (FTIR) analysis revealed that Sb ions could not entirely supplant the Sn ions in the SnO2 lattice for a calcining time of less than 0.5 h,even at a calcining temperature of 1000℃.The ATO nanoparticles calcined at 1000℃ for 3.0h possessed the lowest resistivity of 10.18Ωcm.

  3. A Green Approach to Synthesize Silver Nanoparticles in Starch-co-Poly(acrylamide Hydrogels by Tridax procumbens Leaf Extract and Their Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Siraj Shaik

    2013-01-01

    Full Text Available A series of starch-co-poly(acrylamide (starch-co-PAAm hydrogels were synthesized by employing free radical redox polymerization. A novel green approach, Tridax procumbens (TD leaf extract, was used for reduction of silver ions (Ag+ into silver nanoparticles in the starch-co-PAAm hydrogel network. The formation of silver nanoparticles was confirmed by UV-visible spectroscopy (UV-Vis, thermogravimetric analysis (TGA, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and X-ray diffraction (X-RD studies. 22% of weight loss difference between hydrogel and silver nanocomposite hydrogel (SNCH clearly indicates the formation of silver nanoparticles by TGA. TEM images indicate the successful incorporation of silver nanoparticles ranging from 5 to 10 nm in size and spherical in shape with a narrow size distribution. These developed SNCHs were used to study the antibacterial activity by inhibition zone method against gram-positive and gram-negative bacteria such as Bacillus and Escherichia coli. The results indicated that these SNCHs can be used potentially for biomedical applications.

  4. The influence of parameters of spark discharge generator on dimensional characteristics of synthesized TiO2 nanoparticles

    Directory of Open Access Journals (Sweden)

    Alexey Efimov

    2015-12-01

    Full Text Available A multi-spark discharge generator was used for the synthesis of TiO2 nanoparticles. The nanoparticles were obtained in the form of fractal-like agglomerates with an average size of 30-60 nm consisting of primary spherical nanoparticles with a diameter of about 7-8 nm according to TEM measurements. We found that changing the operating parameters of the generator - energy of the capacitor (2 to18 J, repetition frequency of discharge (0.5 to 4 Hz and velocity of airflow (1.4 to 5.4 m/s changed only the size of the agglomerates while the size of the primary nanoparticles stayed the same.

  5. A Simple and Efficient Method for Synthesizing Te Nanowires from CdTe Nanoparticles with EDTA as Shape Controller under Hydrothermal Condition

    Directory of Open Access Journals (Sweden)

    Fangfang Xue

    2012-01-01

    Full Text Available We developed a simple and efficient method for synthesizing Te nanowires from CdTe nanoparticles with ethylenediaminetetraacetic acid disodium salt dehydrate (EDTA as shape controller under hydrothermal condition. The system could both complete the transformation to Te and reduce the interference of CdTeS by adjusting the concentration of EDTA, which was proved by inductively coupled plasma mass spectrometry, X-ray diffraction patterns, and Raman spectra. It was found that the as-prepared Te nanowires display strong fluorescence emission in the blue-violet region. The nanowires exhibit a pretty good morphology with the average diameter of ca. 30 nm and a length up to micrometer scale. Moreover, a possible transformation mechanism of CdTe nanoparticles into Te nanowires is also discussed.

  6. Biosynthesis, mosquitocidal and antibacterial properties of Toddalia asiatica-synthesized silver nanoparticles: do they impact predation of guppy Poecilia reticulata against the filariasis mosquito Culex quinquefasciatus?

    Science.gov (United States)

    Murugan, Kadarkarai; Venus, Joseph Selvaraj Eugine; Panneerselvam, Chellasamy; Bedini, Stefano; Conti, Barbara; Nicoletti, Marcello; Sarkar, Santosh Kumar; Hwang, Jiang-Shiou; Subramaniam, Jayapal; Madhiyazhagan, Pari; Kumar, Palanisamy Mahesh; Dinesh, Devakumar; Suresh, Udaiyan; Benelli, Giovanni

    2015-11-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. Furthermore, pathogens and parasites polluting water also constitute a severe plague for populations of developing countries. In this study, silver nanoparticles (AgN) were biosynthesized a cheap aqueous extract of T. asiatica leaves as reducing and stabilizing agent. The formation of nanoparticle was confirmed by surface Plasmon resonance band illustrated in UV-vis spectrophotometer. AgN were characterized by FTIR, SEM, EDX, and XRD analyses. AgN were mostly spherical in shape, crystalline in nature, with face-centered cubic geometry, and their mean size was 25-30 nm. T. asiatica aqueous extract and green-synthesized AgN showed excellent larvicidal and pupicidal toxicity against the filariasis vector Culex quinqufasciatus, both in laboratory and field experiments. AgN LC50 ranged from 16.48 (I instar larvae) to 31.83 ppm (pupae). T. asiatica-synthesized were also highly effective in inhibiting growth of Bacillus subtilis, Klebsiella pneumoniae, and Salmonella typhi using the agar disk diffusion and minimum inhibitory concentration protocol. Lastly, we evaluated if sublethal doses of nanoparticles affect predation rates of fishes, Poecilia reticulata, against C. quinquefasciatus. In AgN-contaminated environment, predation of guppies against mosquito larvae was slightly higher over normal laboratory conditions. Overall, this study highlighted that T. asiatica-synthesized AgN are easy to produce, stable over time, and may be employed at low dosages to reduce populations of filariasis vectors, without detrimental effects on predation rates of mosquito natural enemies.

  7. Au-Loaded Titanium Dioxide Nanoparticles Synthesized by Modified Sol-Gel/Impregnation Methods and Their Application to Dye-Sensitized Solar Cells

    OpenAIRE

    Hathaithip Ninsonti; Weerasak Chomkitichai; Akira Baba; Natda Wetchakun; Wiyong Kangwansupamonkon; Sukon Phanichphant; Kazunari Shinbo; Keizo Kato; Futao Kaneko

    2014-01-01

    Au-loaded TiO2 nanoparticles were synthesized by the modified sol-gel method together with the impregnation method. Anatase phase of TiO2 was obtained in all samples with an average particle size of 20 nm. For the enhancement of DSSCs, the dye-sensitized solar cells composed of the ITO/Au-loaded TiO2/N-719/electrolyte/Pt were fabricated. Au-loaded TiO2 films were deposited by using squeegee method. Finally, the fabricated cells were studied upon an irradiation of solar light to study the perf...

  8. Enhancement of photocatalytic activity of combustion-synthesized CeO2/C3N4 nanoparticles

    Science.gov (United States)

    Li, Dong-Feng; Yang, Ke; Wang, Xiao-qin; Ma, Ya-Li; Huang, Gui-Fang; Huang, Wei-Qing

    2015-09-01

    Nanocrystalline CeO2/C3N4 was synthesized via a one-step solution combustion method using urea as fuel for the first time. The effects of the molar ratio of urea to cerium chloride on the photocatalytic activity of the synthesized samples were investigated. The synthesized nanocrystalline CeO2/C3N4 shows small size and large surface exposure area. Photocatalytic degradation of methylene blue demonstrates that the synthesized nanocrystalline CeO2/C3N4 possesses enhanced photocatalytic activity. It is proposed that the enhanced photocatalytic activity might be related to the favorable morphology and structure, and the effective charge separation between C3N4 and CeO2 in the photocatalytic process.

  9. Inhibition of E. coli and S. aureus with selenium nanoparticles synthesized by pulsed laser ablation in deionized water

    Science.gov (United States)

    Guisbiers, G; Wang, Q; Khachatryan, E; Mimun, LC; Mendoza-Cruz, R; Larese-Casanova, P; Webster, TJ; Nash, KL

    2016-01-01

    Nosocomial diseases are mainly caused by two common pathogens, Escherichia coli and Staphylococcus aureus, which are becoming more and more resistant to conventional antibiotics. Therefore, it is becoming increasingly necessary to find other alternative treatments than commonly utilized drugs. A promising strategy is to use nanomaterials such as selenium nanoparticles. However, the ability to produce nanoparticles free of any contamination is very challenging, especially for nano-medical applications. This paper reports the successful synthesis of pure selenium nanoparticles by laser ablation in water and determines the minimal concentration required for ~50% inhibition of either E. coli or S. aureus after 24 hours to be at least ~50 ppm. Total inhibition of E. coli and S. aureus is expected to occur at 107±12 and 79±4 ppm, respectively. In this manner, this study reports for the first time an easy synthesis process for creating pure selenium to inhibit bacterial growth. PMID:27563240

  10. Pre dye treated titanium dioxide nanoparticles synthesized by modified sol-gel method for efficient dye-sensitized solar cells

    Science.gov (United States)

    Ananth, S.; Vivek, P.; Arumanayagam, T.; Murugakoothan, P.

    2015-06-01

    Pure and pre dye treated titanium dioxide nanoparticles were prepared by sol-gel and modified sol-gel methods, respectively. The pre dye treatment has improved the properties of TiO2, such as uniform dye adsorption, reduced agglomeration, improved morphology and less dye aggregation. The brazilein pigment-rich Caesalpinia sappan heartwood extract was used as natural dye sensitizer for pure and pre dye treated TiO2 nanoparticles. Low cost and environment friendly dye-sensitized solar cells (DSSC) fabricated using pure and pre dye treated TiO2 nanoparticles sensitized by natural dye showed solar light to electron conversion efficiencies of 1.09 and 1.65 %, respectively. The pre dye treated TiO2-based DSSC showed 51 % improvement in efficiency when compared to that of conventionally prepared DSSC.

  11. The magnetic and oxidation behavior of bare and silica-coated iron oxide nanoparticles synthesized by reverse co-precipitation of ferrous ion (Fe2+) in ambient atmosphere

    International Nuclear Information System (INIS)

    The synthesis of iron oxide nanoparticles, i.e., magnetite was attempted by using only ferrous ion (Fe2+) as a magnetite precursor, under an ambient atmosphere. The room temperature reverse co-precipitation method was used, by applying two synthesis protocols. The freshly prepared iron oxide was also immediately coated with Stöber silica (SiO2) layer, forming the coreshell structure. The phase, stoichiometry, crystallite and the particle size of the synthesized powders were determined by using X-ray diffraction (XRD) and transmission electron microscope (TEM), while the magnetic and oxidation behaviors were studied by using the vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. Based on the results, the bare iron oxide nanoparticles are in the stoichiometry between the magnetite and the maghemite stoichiometry, i.e., oxidation occurs. This oxidation is depending on the synthesis protocols used. With the silica coating, the oxidation can be prevented, as suggested by the fits of Mössbauer spectra and low temperature magnetic measurement. - Highlights: • Synthesis of magnetite was attempted by using ferrous ion (Fe2+) in air. • The synthesized particle has a stoichiometry in between magnetite and maghemite. • Silica shell partly prevented the oxidation as suggested by magnetic and Mössbauer study

  12. Control-release microcapsule of famotidine loaded biomimetic synthesized mesoporous silica nanoparticles: Controlled release effect and enhanced stomach adhesion in vitro.

    Science.gov (United States)

    Li, Jing; Wang, Hongyu; Yang, Baixue; Xu, Lu; Zheng, Nan; Chen, Hongtao; Li, Sanming

    2016-01-01

    In the present work, control-release microcapsule of famotidine (FMT) loaded biomimetic synthesized mesoporous silica nanoparticles (B-MSNs) was developed, and controlled release effect and stomach adhesion of this formulation in vitro were mainly investigated. B-MSN was previously synthesized and it was amorphous mesoporous nanoparticles with helical channels. Cytotoxicity of B-MSN was studied using human breast cancer cells (MCF-7) and the result indicated that cytotoxicity of B-MSN can be neglected. After loading FMT into B-MSN, specific surface area, pore volume and pore diameter of B-MSN were obviously reduced. In vitro dissolution test showed that B-MSN had the ability to slow down FMT release for 15 min. In order to prolong controlled release effect and remained the advantage of B-MSN (improve drug stability due to its rigid silica framework), the combined application of control-release microcapsule (using cellulose and hydroxypropyl methylcellulose K15M as excipients) with B-MSN was designed. It was obvious that newly designed formulation significantly controlled FMT release with Fickian diffusion mechanism and showed enhanced stomach adhesion in vitro, which has significant value in widening the application of B-MSN in formulation design.

  13. In situ synthesized BSA capped gold nanoparticles: Effective carrier of anticancer drug Methotrexate to MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Murawala, Priyanka [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008 (India); Tirmale, Amruta [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008 (India); National Centre for Cell Science, NCCS, Pune 411007 (India); Shiras, Anjali, E-mail: anjalishiras@nccs.res.in [National Centre for Cell Science, NCCS, Pune 411007 (India); Prasad, B.L.V., E-mail: pl.bhagavatula@ncl.res.in [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008 (India)

    2014-01-01

    The proficiency of MTX loaded BSA capped gold nanoparticles (Au-BSA-MTX) in inhibiting the proliferation of breast cancer cells MCF-7 as compared to the free drug Methotrexate (MTX) is demonstrated based on MTT and Ki-67 proliferation assays. In addition, DNA ladder gel electrophoresis studies, flow cytometry and TUNEL assay confirmed the induction of apoptosis by MTX and Au-BSA-MTX in MCF-7 cells. Notably, Au-BSA-MTX was found to have higher cytotoxicity on MCF-7 cells compared with an equivalent dose of free MTX. The enhanced activity is attributed to the preferential uptake of Au-BSA-MTX particles by MCF-7 cells due to the presence of BSA that acts as a source of nutrient and energy to the rapidly proliferating MCF-7 cells. Moreover, the targeting ability of the drug MTX to the over expressed folate receptors on MCF-7 cells also contributes to the enhanced uptake and activity. Taken together, these results unveil that Au-BSA-MTX could be more effective than free drug for cancer treatment. - Highlights: • Gold nanoparticles prepared using bovine serum albumin as a reducing and capping agent. • These gold nanoparticles are extremely stable under strong electrolyte and pH conditions. • The anticancer drug methotrexate has been loaded on the Au-BSA nanoparticles. • Due to BSA loading these are taken up by cancerous cells preferentially. • Better proficiency in inhibiting MCF-7 cells as compared to the free drug Methotrexate is demonstrated.

  14. In situ synthesized BSA capped gold nanoparticles: Effective carrier of anticancer drug Methotrexate to MCF-7 breast cancer cells

    International Nuclear Information System (INIS)

    The proficiency of MTX loaded BSA capped gold nanoparticles (Au-BSA-MTX) in inhibiting the proliferation of breast cancer cells MCF-7 as compared to the free drug Methotrexate (MTX) is demonstrated based on MTT and Ki-67 proliferation assays. In addition, DNA ladder gel electrophoresis studies, flow cytometry and TUNEL assay confirmed the induction of apoptosis by MTX and Au-BSA-MTX in MCF-7 cells. Notably, Au-BSA-MTX was found to have higher cytotoxicity on MCF-7 cells compared with an equivalent dose of free MTX. The enhanced activity is attributed to the preferential uptake of Au-BSA-MTX particles by MCF-7 cells due to the presence of BSA that acts as a source of nutrient and energy to the rapidly proliferating MCF-7 cells. Moreover, the targeting ability of the drug MTX to the over expressed folate receptors on MCF-7 cells also contributes to the enhanced uptake and activity. Taken together, these results unveil that Au-BSA-MTX could be more effective than free drug for cancer treatment. - Highlights: • Gold nanoparticles prepared using bovine serum albumin as a reducing and capping agent. • These gold nanoparticles are extremely stable under strong electrolyte and pH conditions. • The anticancer drug methotrexate has been loaded on the Au-BSA nanoparticles. • Due to BSA loading these are taken up by cancerous cells preferentially. • Better proficiency in inhibiting MCF-7 cells as compared to the free drug Methotrexate is demonstrated

  15. Modification of MnO{sub 2} nanoparticles with rutin synthesized by Triton X-100 aggregations' template

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yi; Zhu Jun; Han Jie; Guo Rong [School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, Jiangsu (China)], E-mail: guorong@yzu.edu.cn

    2008-10-08

    Manganese dioxide (MnO{sub 2}) nanoparticles have been prepared through the redox reaction between KMnO{sub 4} and the nonionic surfactant Triton X-100 with the aid of rod-like micelles, hexagonal liquid crystals and reverse micelle templates, in which Triton X-100 acts both as template and reductant. MnO{sub 2} nanorods (20-50 nm in diameter) can be obtained in rod-like micelles and hexagonal liquid crystals, whereas MnO{sub 2} nanospheres (about 85 nm in diameter) are formed in reverse micelles. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize the products. Modification of MnO{sub 2} nanoparticles by rutin has been discussed using fluorescence spectra and UV-vis spectra, and the free radical eliminating investigations of surface-modified MnO{sub 2} nanoparticles with rutin show that MnO{sub 2} nanoparticles can improve the free-radical-scavenging activity of rutin.

  16. Investigation of synthesized silica coating Fe3O4 nanoparticles efficiency in removal of NOM from water

    Directory of Open Access Journals (Sweden)

    E. Karimi pasandideh

    2014-05-01

    Conclusion: Having high number of active surface sites, magnetic properties, easily separation using magnetic field, and its cost-effectiveness, the Fe3O4/SiO2 nanoparticles could be used as an efficient adsorbent in removal of humic acid from water.

  17. Magnetic and optical properties of manganese doped ZnO nanoparticles synthesized by sol-gel technique

    KAUST Repository

    Omri, Karim

    2013-08-01

    Mn doped ZnO nanoparticles with different doping concentration (1, 2, 3, 4, 5 at.%) were prepared by sol-gel method using supercritical drying conditions of ethyl alcohol. The structural, morphological, optical and magnetic properties of the as-prepared nanoparticles were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV measurements and superconducting quantum interference device (SQUID). The structural properties showed that the undoped and Mn doped ZnO nanoparticles exhibit hexagonal wurtzite structure. From the optical studies, the transmittance in UV region was decreased with the increase of Mn concentration. For Mn doped ZnO nanoparticles the optical band gap varies between 3.34 eV and 3.22 eV. It was found that the doping Mn 2+ ions have a significant influence on the optical properties. The magnetic characterization of the samples with 1% and 5% Mn concentrations reveal diamagnetic behavior for the first one and the presence of both paramagnetic and ferromagnetic behavior for the second. The room ferromagnetic component is due to the presence of the secondary phase ZnOMn3 which is confirmed by XRD study. © 2013 Elsevier Ltd. All rights reserved.

  18. Crystal structure of superparamagnetic Mg0.2Ca0.8Fe2O4 nanoparticles synthesized by sol–gel method

    International Nuclear Information System (INIS)

    Powders of magnetic iron oxide nanoparticles (Mg0.2Ca0.8Fe2O4) were prepared by a sol–gel method using ethylene glycol and nitrates of Fe, Ca and Mg as starting materials. Those powders were heat treated at different temperatures (573, 673, 773 and 873 K). In order to evaluate the effect of the heat treatment temperature on the nanoferrites properties, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques were used. It was found that the reaction products exhibit nanometric sizes and superparamagnetic behavior. It is also demonstrated that, as the heat treatment temperature increases, the particle size and the saturation magnetization of the nanoferrites are increased. - Highlights: • Mg0.2Ca0.8Fe2O4 superparamagnetic nanoparticles were successfully synthesized. • Particle average sizes of Ca–Mg ferrites were within the range of 8–25 nm. • The nanoferrite treated at 873 K showed a stoichiometry close to Mg0.2Ca0.8Fe2O4. • The heat treatment temperature has a strong effect on the crystal structure. • These nanoparticles are potential materials for magnetic hyperthermia

  19. Structural characterization and self-assembly into superlattices of iron oxide-gold core-shell nanoparticles synthesized via a high-temperature organometallic route

    International Nuclear Information System (INIS)

    Iron oxide-gold core-shell nanocrystals have been synthesized by the thermal decomposition of iron pentacarbonyl and the subsequent reduction of gold acetate by 1,2-hexadecanediol with oleic acid and oleylamine as stabilizers. Their size, structure, composition, and optical and magnetic properties were characterized. The resultant nanoparticles were nearly monodisperse with a complete core-shell structure, and the shell thickness could be tuned via the seed-mediated growth. Also, they exhibited an absorption band at 520 nm owing to the surface plasmon resonance of Au shells and were nearly superparamagnetic due to the presence of the iron cores. By analyzing the x-ray adsorption near-edge structure (XANES) spectrum and the x-ray photoelectron spectroscopy (XPS) spectra of the fast etching mode, the iron cores were shown to be oxidized but the oxidation was incomplete in the inner region. Noteworthily, the iron oxide-Au nanoparticles could self-assemble into 2D and 3D superlattices. The packing density increased while approaching the center of assembly, leading to the variation of superstructures from a 2D nearly hcp monolayer to a 3D hcp superlattice and a 3D hexagonal superlattice. Moreover, hydrophilic iron oxide-Au core-shell nanoparticles were also obtained by surface modification with mercaptoacetic acid via a phase transfer route.

  20. Dietary supplementation of green synthesized manganese-oxide nanoparticles and its effect on growth performance, muscle composition and digestive enzyme activities of the giant freshwater prawn Macrobrachium rosenbergii.

    Science.gov (United States)

    Asaikkutti, Annamalai; Bhavan, Periyakali Saravana; Vimala, Karuppaiya; Karthik, Madhayan; Cheruparambath, Praseeja

    2016-05-01

    The green synthesized Mn3O4 nanoparticles (manganese-oxide nanoparticles) using Ananas comosus (L.) peel extract was characterized by various techniques. HR-SEM photograph showed that manganese-oxide nanoparticles (Mn-oxide NPs) were spherical in shape, with an average size of 40-50 nm. The Zeta potential revealed the surface charge of Mn-oxide NPs to be negative. Further, the Mn-oxide NPs were dietary supplemented for freshwater prawn Macrobrachium rosenbergii. The experimental basal diets were supplemented with Mn-oxide NPs at the rates of 0 (control), 3.0, 6.0, 9.0, 12, 15 and 18 mg/kg dry feed weight. The as-supplemented Mn-oxide NPs were fed in M. rosenbergii for a period of 90 days. The experimental study demonstrated that prawns fed with diet supplemented with 3-18 mg Mn-oxide NPs/kg shows enhanced (P0.05) alterations in prawns fed with 3.0-18 mg/kg of Mn-oxide NPs supplemented diets. Consequently, the present work proposed that 16 mg/kg of Mn-oxide NPs could be supplemented for flexible enhanced survival, growth and production of M. rosenbergii. Therefore, the data of the present study recommend the addition of 16 mg/kg of Mn-oxide NPs diet to developed prawn growth and antioxidant defense system.

  1. Photo-catalytic activity of Plasmonic Ag@AgCl nanoparticles (synthesized via a green route) for the effective degradation of Victoria Blue B from aqueous phase.

    Science.gov (United States)

    Devi, Th Babita; Begum, Shamima; Ahmaruzzaman, M

    2016-07-01

    This study reports a green process for the fabrication of Ag@AgCl (silver@silver chloride) nanoparticles by using Aquilaria agallocha (AA) leaves juice without using any external reagents. The effect of various reaction parameters, such as reaction temperature, reaction time and concentration of Aquilaria agallocha leaves juice in the formation of nanoparticles have also been investigated. From the FTIR spectra of leaves juice and phytochemicals test, it was found that flavonoids present in the leaves are responsible for the reduction of Ag(+) ions to Ag(0) species and leads to the formation of Ag@AgCl NPs. The synthesized Ag@AgCl NPs were utilized for the removal of toxic and hazardous dyes, such as Victoria Blue B from aqueous phase. Approximately, 99.46% degradation of Victoria Blue B dye were observed with Ag@AgCl NPs. Furthermore, the photocatalytic activity of the Ag@AgCl nanoparticles was unchanged after 5cycles of operation. PMID:27152674

  2. Effect of temperature on structural, optical and photoluminescence studies on ZnO nanoparticles synthesized by the standard co-precipitation method

    Science.gov (United States)

    Raj, K. Pradeev; Sadayandi, K.

    2016-04-01

    This present study brings the synthesis of Zinc oxide (ZnO) nanoparticles (NPs) by the standard aqueous chemical route technique. The impact of calcination temperature on the extent of the ZnO nanoparticles is studied for its lattice constraints. X-ray diffraction (XRD) affirms the hexagonal Wurtzite structure of the synthesized ZnO nanoparticles. From the Williamson-Hall (W-H) plot, positive slope is inferred for pure and calcined ZnO NPs and confirms the presence of tensile strain. From the SEM images it is found that the crystallinity enhances with calcination temperature. From the optical studies, it is found that the band gap energy decreases with improved transmission. The Photoluminescence (PL) spectrum reveals the UV emission is strong near the band-edge. The emission peaks around 400-480 nm result in blue emission and the peaks around 540-560 nm result in green emission. Decrease in band gap energy and enhancement in PL studies reveal the red shift of the calcined ZnO exhibiting solid quantum confinements.

  3. Structure and morphologies of ZnO nanoparticles synthesized by pulsed laser ablation in liquid: Effects of temperature and energy fluence

    Energy Technology Data Exchange (ETDEWEB)

    Guillén, G. García; Palma, M.I. Mendivil [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455 (Mexico); Krishnan, B. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455 (Mexico); Universidad Autónoma de Nuevo León – Centro de Innovación, Investigación y Desarrollo de Ingeniería y Tecnología, Apodaca, Nuevo León 66600 (Mexico); Avellaneda, D.; Castillo, G.A.; Roy, T.K. Das [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455 (Mexico); and others

    2015-07-15

    Zinc oxide nanoparticles were prepared by pulsed laser ablation of a zinc metal target at different water temperatures (room temperature, 50, 70 and 90 °C). Ablation was carried out using 532 nm output from a pulsed (10 ns, 10 Hz) Nd:YAG laser at three different laser fluence. Analysis of the morphology, crystalline phase, elemental composition, optical and luminescent properties were done using Transmission Electron Microscopy (TEM), X-Ray Photoelectron Spectroscopy (XPS), UV–visible absorption spectroscopy and photoluminescence spectroscopy. TEM analysis showed that a change in temperature resulted in ZnO and Zn(OH){sub 2} nanoparticles with different sizes and morphologies. XPS results confirmed the compositions and chemical states of these nanoparticles. These zinc nanomaterials showed emission in the ultraviolet (UV) and blue regions. The results of this work demonstrated that by varying the liquid medium temperature, the structure, composition, morphology and optical properties of the nanomaterials could be modified during pulsed laser ablation in liquid. - Graphical abstract: Display Omitted - Highlights: • Zinc nanomaterial colloids were synthesized by PLAL. • Effects of laser fluence and the distilled water temperature were analyzed. • The final structure varied with the distilled water temperature and laser fluence. • The morphology was dependent on the distilled water temperature and laser fluence. • Zinc nanocolloids showed emission in the UV and blue region.

  4. Structure and morphologies of ZnO nanoparticles synthesized by pulsed laser ablation in liquid: Effects of temperature and energy fluence

    International Nuclear Information System (INIS)

    Zinc oxide nanoparticles were prepared by pulsed laser ablation of a zinc metal target at different water temperatures (room temperature, 50, 70 and 90 °C). Ablation was carried out using 532 nm output from a pulsed (10 ns, 10 Hz) Nd:YAG laser at three different laser fluence. Analysis of the morphology, crystalline phase, elemental composition, optical and luminescent properties were done using Transmission Electron Microscopy (TEM), X-Ray Photoelectron Spectroscopy (XPS), UV–visible absorption spectroscopy and photoluminescence spectroscopy. TEM analysis showed that a change in temperature resulted in ZnO and Zn(OH)2 nanoparticles with different sizes and morphologies. XPS results confirmed the compositions and chemical states of these nanoparticles. These zinc nanomaterials showed emission in the ultraviolet (UV) and blue regions. The results of this work demonstrated that by varying the liquid medium temperature, the structure, composition, morphology and optical properties of the nanomaterials could be modified during pulsed laser ablation in liquid. - Graphical abstract: Display Omitted - Highlights: • Zinc nanomaterial colloids were synthesized by PLAL. • Effects of laser fluence and the distilled water temperature were analyzed. • The final structure varied with the distilled water temperature and laser fluence. • The morphology was dependent on the distilled water temperature and laser fluence. • Zinc nanocolloids showed emission in the UV and blue region

  5. Structure and electrochemical properties of Mg{sub 2}SnO{sub 4} nanoparticles synthesized by a facile co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Hao, E-mail: htang@ncu.edu.cn [Institute of Photovoltaics, Nanchang University, Nanchang 330031 (China); Cheng, Cuixia; Yu, Gaige [Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, Hubei Province, South-Central University for Nationalities, Wuhan 430074 (China); Liu, Haowen, E-mail: liuhwchem@hotmail.com [Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, Hubei Province, South-Central University for Nationalities, Wuhan 430074 (China); Chen, Weiqing [Institute of Photovoltaics, Nanchang University, Nanchang 330031 (China)

    2015-06-01

    Nanosized Mg{sub 2}SnO{sub 4} has been synthesized by a facile co-precipitation method. The structure and morphology of the as-prepared samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), fourier Transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It is found that Mg{sub 2}SnO{sub 4} sample is very sensitive to the aging time of the precursor. The single phase Mg{sub 2}SnO{sub 4} nanoparticles with ∼23 nm can be obtained at 900 °C using the aging 35 min percusor as source. The electrochemical properties of the powder obtained at 900 °C are investigated by galvanostatic discharge-charge tests and cyclic voltammograms (CVs). The initial specific discharge capacity reaches as high as 927.7 mAh g{sup −1} at 0.2 mA cm{sup −2} in 0.05–3.0 V, which indicates that Mg{sub 2}SnO{sub 4} nanoparticles could be a promising candidate of anode material for Li-ion batteries. - Highlights: • Nanosized Mg{sub 2}SnO{sub 4} has been synthesized by a facile co-precipitation method. • We find that Mg{sub 2}SnO{sub 4} sample is very sensitive to the ageing time of the precursor. • The single phase Mg{sub 2}SnO{sub 4} nanoparticles with about 23 nm can be obtained by calcining the ageing 35 min percusor at 900 °C. • The obtained powders show a better electrochemical performance.

  6. Effects of Mn on the magnetic and optical properties and photocatalytic activities of NiO nanoparticles synthesized via the simple precipitation process

    Energy Technology Data Exchange (ETDEWEB)

    Anandan, K., E-mail: anand.nanoscience@yahoo.com; Rajendran, V.

    2015-09-15

    Graphical abstract: - Highlights: • Pure and Mn doped NiO were synthesized via very simple precipitation method. • Mn concentrations played a vital role to modify the properties of NiO. • Quantum confinement effect was occurred in the UV–vis spectra due to lower size. • MeO dye was degraded up to 84.43% by Mn doped NiO compared with pure 63.63%. • Proposed method has the important advantage of being simple, fast and cost effective. - Abstract: Pure and Mn doped NiO nanoparticles have been successfully synthesized via the simple precipitation process. The XRD and TEM studies have confirmed that the prepared NiO nanoparticles sizes decreased with the manganese insertion into nickel oxide. The observed antiferro to superpara and ferromagnetic transition on Mn doping in NiO is understood on the basis of Mn occupying Ni sites, and breaking the translational symmetry of the parent antiferromagnetic correlation. The measured band gap energies (E{sub g} = 3.78, 3.81, 3.84 and 3.90 eV) increased with decreasing particles size, which indicated the quantum confinement effect. The broad visible emission at 527 nm originates from the deep levels of the prepared NiO nanoparticles and is due to the presence of V{sub o} and Ni{sub (in)} defects. The photocatalytic degradation of the methyl orange dye was studied for the prepared pure and doped samples, and the mechanism has been discussed.

  7. Synthesizing A Phase Changing Bistable Electroactive Polymer And Silver Nanoparticles Coated Fabric As A Resistive Heating Element

    Science.gov (United States)

    Ren, Zhi

    Transducer technologies that convert energy from one form to another (e.g. electrical energy to mechanical energy or thermal energy and vise versa) are considered as the basic building blocks of robots and wearable electronics, two of the rapidly emerging technologies that impact our daily life. With an emphasis on developing the essential smart materials, this dissertation focuses on two specific transducer technologies, bistable large-strain electro-mechanical actuation and resistive Joule heating, in pursuit of refreshable Braille electronic displays and wearable thermal management element, respectively. Dielectric elastomers (DEs) have been intensively studied for their promising ability to mimic human muscles in providing efficient electro-mechanical actuation. They exhibit a unique combination of properties, including large strain, fast response, high energy density, mechanical compliancy, lightweight, and low cost. However, the softness of the DE materials, which is a prerequisite for electrically induced large actuation strain, has been hindering their application in adaptive structures. In these applications such as braille displays, a certain amount of mechanical support is necessary in addition to large strains for the device or system to function. Bistable electroactive polymers (BSEP) that leverage the electrically induced large-strain actuation of DE actuators and the bi-stable rigid-to-rigid deformation of shape memory polymers are innovated to provide large electrical actuation strain in their rubbery state and fix the deformation by cooling down to room temperature to incorporate mechanical rigidity. BSEP materials that can suppress electromechanical instability and exhibit stable mechanical properties in the rubbery state are desired. A bimodal BSEP material with a glass transition temperature right above room temperature has been synthesized employing simple UV curing process. The BSEP has a large storage modulus over 1GPa at room temperature

  8. Preparation and characterization of BaLiF3:Er3+ nanoparticles by the hydrothermal microemulsion synthesized method

    Institute of Scientific and Technical Information of China (English)

    YAN Jinghui; LI Zhongtian; WANG Linkun; CAO Liangjun; WANG Suqing; SHI Chunshan

    2008-01-01

    Nanoparticles of BaLiF3:Er3+ were prepared from the quaternary microemulsions of Cetyltrim-Enthyl Ammonium Bromide (CTAB), n-butanol, n-octane, and water, using the hydrothermal-microemulsion technique. The complex fluorides were characterized by means of X-ray power diffraction, Environmental Scanning Electron Microscopy (ESEM), and fluorescence spectra. The positions and intensities of the peaks in the XRD pattern of the final products indicate the formation of BaLiF3:Er3+. No other peaks or impurities were detected. The average size of the nanoparticles, calculated with the Debye-Scherrer equation was 98.45 nm, which was in agreement with the result of ESEM. The infrared fluorescence spectra consisted of four peaks with a predominant peak located at 1540 nm.

  9. The green synthesis, characterization, and evaluation of the biological activities of silver nanoparticles synthesized from Leptadenia reticulata leaf extract

    Science.gov (United States)

    Kumara Swamy, M.; Sudipta, K. M.; Jayanta, K.; Balasubramanya, S.

    2015-01-01

    Biosynthesis of silver nanoparticles (Ag Nps) was carried out using methanol leaves extract of L. reticulata. Ag Nps were characterized based on the observations of UV-visible spectroscopy, transmission electron microscopy, and X-ray diffraction (XRD) analysis. These Ag Nps were tested for antimicrobial activity by agar well diffusion method against different pathogenic microorganisms and antioxidant activity was performed using DPPH assay. Further, the in vitro cytotoxic effects of Ag Nps were screened against HCT15 cancer cell line and viability of tumor cells was confirmed using MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a yellow tetrazole)) assay. The nuclear condensation was studied using the propidium iodide-staining method. The color change from green to dark brown and the absorbance peak at about 420 nm indicated the formation of nanoparticles. XRD pattern showed characteristic peaks indexed to the crystalline planes (111), (200) and (220) of face-centered cubic silver. The nanoparticles were of spherical shape with varying sizes ranging from 50 to 70 nm. Biosynthesized Ag Nps showed potent antibacterial activity and effective radical scavenging activity. MTT assay revealed a dose-dependent decrease in cell viability. Microscopic observations showed distinct cellular morphological changes indicating unhealthy cells, whereas the control appeared normal. Increase in the number of propidium iodide positive cells were observed in maximum concentration. Methanolic leaf extract of L. reticulata acts as an excellent capping agent for the formation of silver nanoparticles and demonstrates immense biological activities. Hence, these Ag NPs can be used as antibacterial, antioxidant as well as cytotoxic agent in treating many medical complications.

  10. Investigation of synthesized silica coating Fe3O4 nanoparticles efficiency in removal of NOM from water

    OpenAIRE

    E. Karimi pasandideh; R Rezaei Kalantary; S. Nasseri; A. H. Mahvi; R Nabizadeh; A Esrafili

    2014-01-01

    Background and Objective: The presence of natural organic materials (NOM) in water resources affects its quality (i.e. color, odor, and taste). In addition, it leads to the fouling of filters and membranes and reduces water treatment efficiency during flocculation/ coagulation. Moreover, NOM reacts with disinfectants and produces byproducts (DBPs), which are harmful to human health. Magnetic nanoparticles have been reported as effective adsorbents for the removal of pollutants from the aqueou...

  11. Structural, chemical and optical evaluation of Cu-doped ZnO nanoparticles synthesized by an aqueous solution method

    Energy Technology Data Exchange (ETDEWEB)

    Iribarren, A., E-mail: augusto@imre.oc.uh.cu [Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba); Hernández-Rodríguez, E. [Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba); Maqueira, L. [Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba); Facultad de Química, Universidad de La Habana, Zapata y G, Vedado, Plaza, La Habana 10400 (Cuba)

    2014-12-15

    Highlights: • Cu-doped ZnO nanoparticles obtained by chemical synthesis. • Substitutional or interstitial Cu into ZnO lead specific structural, chemical, and optical changes. • Incorporation efficiency of Cu atoms in ZnO as a function of the Cu concentration in the precursor dissolution. - Abstract: In this work a study of ZnO and Cu-doped ZnO nanoparticles obtained by chemical synthesis in aqueous media was carried out. Structural analysis gave the dominant presence of wurtzite ZnO phase forming a solid solution Zn{sub 1−x}Cu{sub x}O. For high Cu doping CuO phase is also present. For low Cu concentration the lattice shrinks due to Cu atoms substitute Zn atoms. For high Cu concentration the lattice enlarges due to predominance of interstitial Cu. From elemental analysis we determined and analyzed the incorporation efficiency of Cu atoms in Zn{sub 1−x}Cu{sub x}O as a function of the Cu concentration in the precursor dissolution. Combining structural and chemical results we described the Cu/Zn precursor concentrations r{sub w} in which the solid solution of Cu in ZnO is predominant. In the region located at r{sub w} ≈ 0.2–0.3 it is no longer valid. For Cu/Zn precursor concentration r{sub w} > 0.3 interstitial Cu dominates, and some amount of copper oxide appears. As the Cu concentration increases, the effective size of nanoparticles decreases. Photoluminescence (PL) measurements of the Cu-doped ZnO nanoparticles were carried out and analyzed.

  12. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-González, R.

    2010-03-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  13. Inhibition of E. coli and S. aureus with selenium nanoparticles synthesized by pulsed laser ablation in deionized water

    Directory of Open Access Journals (Sweden)

    Guisbiers G

    2016-08-01

    Full Text Available G Guisbiers,1 Q Wang,2 E Khachatryan,1 LC Mimun,1 R Mendoza-Cruz,1 P Larese-Casanova,3 TJ Webster,2,4,5 KL Nash1 1Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, TX, 2Department of Bioengineering, 3Department of Civil and Environmental Engineering, 4Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 5Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: Nosocomial diseases are mainly caused by two common pathogens, Escherichia coli and Staphylococcus aureus, which are becoming more and more resistant to conventional antibiotics. Therefore, it is becoming increasingly necessary to find other alternative treatments than commonly utilized drugs. A promising strategy is to use nanomaterials such as selenium nanoparticles. However, the ability to produce nanoparticles free of any contamination is very challenging, especially for nano-medical applications. This paper reports the successful synthesis of pure selenium nanoparticles by laser ablation in water and determines the minimal concentration required for ~50% inhibition of either E. coli or S. aureus after 24 hours to be at least ~50 ppm. Total inhibition of E. coli and S. aureus is expected to occur at 107±12 and 79±4 ppm, respectively. In this manner, this study reports for the first time an easy synthesis process for creating pure selenium to inhibit bacterial growth. Keywords: nosocomial disease, bacteria, antibiotics resistant, cytotoxicity

  14. Effect of heating rate and plant species on the size and uniformity of silver nanoparticles synthesized using aromatic plant extracts

    Science.gov (United States)

    Hernández-Pinero, Jorge Luis; Terrón-Rebolledo, Manuel; Foroughbakhch, Rahim; Moreno-Limón, Sergio; Melendrez, M. F.; Solís-Pomar, Francisco; Pérez-Tijerina, Eduardo

    2016-05-01

    Mixing aqueous silver solutions with aqueous leaf aromatic plant extracts from basil, mint, marjoram and peppermint resulted in the synthesis of quasi-spherical silver nanoparticles in a range of size between 2 and 80 nm in diameter as analyzed by analytical high-resolution electron microscopy. The average size could be controlled by applying heat to the initial reaction system at different rates of heating, and by the specific botanical species employed for the reaction. Increasing the rate of heating resulted in a statistically significant decrease in the size of the nanoparticles produced, regardless of the species employed. This fact was more evident in the case of marjoram, which decreased the average diameter from 27 nm at a slow rate of heating to 8 nm at a high rate of heating. With regard to the species, minimum sizes of mint yielded an average size between 10 and 25 nm. The results indicate that aromatic plant extracts can be used to achieve the controlled synthesis of metal nanoparticles.

  15. Enhancing the Mobilization of Native Phosphorus in the Mung Bean Rhizosphere Using ZnO Nanoparticles Synthesized by Soil Fungi.

    Science.gov (United States)

    Raliya, Ramesh; Tarafdar, Jagadish Chandra; Biswas, Pratim

    2016-04-27

    Phosphorus (P) is a limiting factor to plant growth and productivity in almost half of the world's arable soil, and its uptake in plants is often constrained because of its low solubility in the soil. To avoid repeated and large quantity application of rock phosphate as a P fertilizer and enhance the availability of native P acquisition by the plant root surface, in this study a biosynthesized ZnO nanoparticle was used. Zn acts as a cofactor for P-solubilizing enzymes such as phosphatase and phytase, and nano ZnO increased their activity between 84 and 108%. The level of resultant P uptake in mung bean increased by 10.8%. In addition, biosynthesized ZnO also improves plant phenology such as stem height, root volume, and biochemical indicators such as leaf protein and chlorophyll contents. In the rhizosphere, increased chlorophyll content and root volume attract microbial populations that maintain soil biological health. ICP-MS results showed ZnO nanoparticles were distributed in all plant parts, including seeds. However, the concentration of Zn was within the limit of the dietary recommendation. To the best of our knowledge, this is the first holistic study focusing on native P mobilization using ZnO nanoparticles in the life cycle of mung bean plants. PMID:27054413

  16. A novel hydrolysis method to synthesize chromium hydroxide nanoparticles and its catalytic effect in the thermal decomposition of ammonium perchlorate

    International Nuclear Information System (INIS)

    Highlights: ► Synthesis of Cr(OH)3 nanoparticles in Cr3+–F− aqueous solution. ► The F− ion tailors coagulated materials, Cr(OH)3 nanoparticles are obtained. ► Adding nanosized Cr(OH)3, AP thermal decomposition temperature decreases to 200 °C. ► The nanosized Cr(OH)3 catalyzes NH3 oxidation, accelerating AP thermal decomposition. - Abstract: A procedure for the preparation of spherical Cr(OH)3 nanoparticles was developed based on the aging of chromium nitrate aqueous solutions in the presence of sodium fluoride, urea, and polyvinylpyrrolidone. Using scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy, the morphological characteristics of Cr(OH)3 were controlled by altering the molar ratio of fluoride ion to chromium ion, as well as the initial pH and chromium ion concentration. The prepared nanosized Cr(OH)3 decreased the temperature required to decompose ammonium perchlorate from 450 °C to about 250 °C as the catalyst. The possible catalytic mechanism of the thermal decomposition of ammonium perchlorate was also discussed.

  17. Larvicidal and pupicidal activity of synthesized silver nanoparticles using Leucas aspera leaf extract against mosquito vectors, Aedes aegypti and Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    S. Sivapriyajothi

    2014-08-01

    Full Text Available Mosquitoes are one of the most medically significant groups of vectors, having an ability to transmit parasites and pathogens that can have devastating impacts on humans. The development of reliable and ecofriendly processes for the synthesis of metallic nanoparticles is an important step in the field of application of nanotechnology. In this study, we address the biosynthesis of silver nanoparticles (AgNPs using Leucas aspera leaf extract, and evaluate its lethal concentration (LC50 and LC90 values against first to fourth instar larvae and pupae of the mosquito vectors, Aedes aegypti and Anopheles stephensi. The nanoparticles were characterized by UV-Vis spectrum, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transformed infrared spectroscopy analysis. Larvae and pupae were exposed to varying concentrations of aqueous extracts of synthesized AgNPs for 24 h. The maximum mortality was observed from synthesized AgNPs, with LC50 values for I-IV instars and pupae ranging from 13.06 to 25.54, and LC90 values ranging from 24.11 to 47.34 for A. aegypti; for A. stephensi, the corresponding LC50 values ranged from 12.45 to 22.26, and the LC90 values ranged from 23.50 to 42.95. With methanol leaf extract of L. aspera against A. aegypti, the LC50 values ranged from 174.89 to 462.96 and the LC90 values ranged from 488.16 to 963.74; for A. stephensi, the corresponding LC50 values ranged from 148.93 to 417.07 and the LC90 values ranged from 449.72 to 912.94. The study suggests that nanoparticles could be a preferred alternative to the most hazardous existing chemical pesticides, contributing to a more healthy environment by providing an ideal ecological and user-friendly vector control strategy for managing malaria and dengue, and contributing to their eventual elimination in the near future.

  18. Magnetic, structural, and electronic properties of iron sulfide Fe{sub 3}S{sub 4} nanoparticles synthesized by the polyol mediated process

    Energy Technology Data Exchange (ETDEWEB)

    Lyubutin, I. S., E-mail: lyubutin@ns.crys.ras.ru; Starchikov, S. S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Lin, Chun-Rong, E-mail: crlin@mail.stut.edu.tw; Lu, Shin-Zong; Shaikh, Muhammad Omar [Southern Taiwan University of Science and Technology, Department of Mechanical Engineering, Institute of Nanotechnology (China); Funtov, K. O.; Dmitrieva, T. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Ovchinnikov, S. G., E-mail: sgo@iph.krasn.ru; Edelman, I. S.; Ivantsov, R. [Siberian Branch of Russian Academy of Sciences, Kirensky Institute of Physics (Russian Federation)

    2013-01-15

    Iron sulfide nanoparticles Fe{sub 3}S{sub 4} with the spinel-type crystal structure were synthesized by the polyol mediated process. The particle size depends on preparation conditions and varies from 9 to 20 nm. Moessbauer data have revealed that the dominating fraction of iron ions in the 9-nm sample is in the high-spin ferric state. This implies an occurrence of the cation vacancies in nonstoichiometric greigite. The stoichiometric phase of greigite Fe{sub 3}S{sub 4} dominates in the 18-nm-size nanoparticles. Magnetic measurements have shown a ferrimagnetic behavior of all samples at temperatures between 78 and 300 K. The estimated value of magnetic moment of the stoichiometric greigite nanoparticles is about 3.5 {mu}{sub B} per Fe{sub 3}S{sub 4} unit. The Moessbauer spectra indicate a superparamagnetic behavior of small particles, and some fraction of superparamagnetic phase is observed in all samples synthesized which may be caused by the particle size distribution. The blocking temperatures of T{sub B} Almost-Equal-To 230 and 250 K are estimated for the 9 and 14 nm particles, respectively. The Moessbauer parameters indicate a great degree of covalency in the Fe-S bonds and support the fast electron Fe{sup 3+} Leftwards-Arrow-Over-Rightwards-Arrow Fe{sup 2+} exchange in the B-sites of greigite. An absence of the Verwey transition at temperatures between 90 and 295 K is established supporting a semimetal type of conductivity. The temperature and magnetic field dependences of the magnetic circular dichroism (MCD) of optical spectra were measured in Fe{sub 3}S{sub 4} for the first time. The spectra differ substantially from that of the isostructural oxide Fe{sub 3}O{sub 4}. It is supposed that the MCD spectra of greigite nanoparticles result from the collective electron excitations in a wide band with superimposed peaks of the d-d transitions in Fe ions.

  19. An Investigation of the Cytotoxicity and Caspase-Mediated Apoptotic Effect of Green Synthesized Zinc Oxide Nanoparticles Using Eclipta prostrata on Human Liver Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Ill-Min Chung

    2015-08-01

    Full Text Available Cancer is a leading cause of death worldwide and sustained focus is on the discovery and development of newer and better tolerated anticancer drugs, especially from plants. In the present study, a simple, eco-friendly, and inexpensive approach was followed for the synthesis of zinc oxide nanoparticles (ZnO NPs using the aqueous leaf extract of Eclipta prostrata. The synthesized ZnO NPs were characterized by UV-visible absorption spectroscopy, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX, High-resolution transmission electron microscopy (HRTEM, and Selected area (electron diffraction (SAED. The HRTEM images confirmed the presence of triangle, radial, hexagonal, rod, and rectangle, shaped with an average size of 29 ± 1.3 nm. The functional groups for synthesized ZnO NPs were 3852 cm−1 for H-H weak peak, 3138 cm−1 for aromatic C-H extend, and 1648 cm−1 for Aromatic ring stretch. The 3-(4,5-Dimethylthiazol-2-yl-2,5-Diphenyltetrazolium Bromide (MTT, caspase and DNA fragmentation assays were carried out using various concentrations of ZnO NPs ranging from 1 to 100 mg/mL. The synthesized ZnO NPs showed dose dependent cytopathic effects in the Hep-G2 cell line. At 100 mg/mL concentration, the synthesized ZnO NPs exhibited significant cytotoxic effects and the apoptotic features were confirmed through caspase-3 activation and DNA fragmentation assays.

  20. Effect of Co Doping on Structural and Magnetic Properties of ZnO Nanoparticles Synthesized by Novel Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    V. Rajendar

    2013-03-01

    Full Text Available ZnO is a wide band gap semiconductor (3.37 eV with a high exciton binding energy (60 meV, which has wide applications in advanced optoelectronic devices. The theoretical prediction of room temperature ferromagnetism will be possible through the investigation of diluted magnetic semiconductors such as transition metal doped ZnO, especially Cobalt doped ZnO. The aim of the work is to synthesize Zn1 – xCoxO (x = 0 and x = 0.20 nanostructures through a novel urea based auto combustion method and its characterization. The Structural and Magnetic studies of the synthesized Zn1 – xCoxO Nano powders were carried out by X-Ray diffraction (XRD technique and Vibrating Sample Magnetometer (VSM, respectively.

  1. Decomposition of NO in gas phase by gold nanoparticles supported on titanium dioxide synthesized by the deposition-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Fernandez, J., E-mail: javier.fernandez@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados, Av. Miguel de Cervantes 120, Complejo Industrial C.P. 31109, Chihuahua, Chih. (Mexico); Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Eje Central Lazaro Cardenas 152, C.P. 07730, D.F. (Mexico); Zanella, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, UNAM, Circuito exterior S/N, Ciudad Universitaria, C.P. 04510, A.P. 70-186, Delegacion Coyoacan, D.F. (Mexico); Aguilar-Elguezabal, A. [Centro de Investigacion en Materiales Avanzados, Av. Miguel de Cervantes 120, Complejo Industrial C.P. 31109, Chihuahua, Chih. (Mexico); Arizabalo, R.D.; Castillo, S.; Moran-Pineda, M. [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Eje Central Lazaro Cardenas 152, C.P. 07730, D.F. (Mexico)

    2010-10-25

    In the present work, the synthesis, characterization and photoactivity concerning the nitrogen monoxide (NO) decomposition of sol-gel Au/TiO{sub 2} photocatalysts are reported. TiO{sub 2} was prepared by gelling titanium (IV) isopropoxide, and gold nanoparticles were added by the deposition-precipitation method with urea. The catalysts with different gold concentrations were characterized by the following techniques: BET, XRD, UV-vis and dark-field TEM. It was found that by using this synthesis method, a high dispersion of gold nanoparticles on TiO{sub 2} was reached (4.4-6.7 nm), and the obtained structure lead to a band gap energy that is lower than the one observed for undoped TiO{sub 2}. A NO + O{sub 2} mixture (150 ppm) was used to evaluate the photocatalytic activity in situ, at room temperature, under atmospheric pressure and a UV lamp was used as radiation source. The photocatalytic conversion of nitrogen monoxide (NO) was followed by FTIR, which reached 96% in 60 min. The Au/TiO{sub 2} materials showed an enhanced photocatalytic activity when compared with the reference TiO{sub 2}.

  2. Green in-situ synthesized silver nanoparticles embedded in bacterial cellulose nanopaper as a bionanocomposite plasmonic sensor.

    Science.gov (United States)

    Pourreza, Nahid; Golmohammadi, Hamed; Naghdi, Tina; Yousefi, Hossein

    2015-12-15

    Herein, we introduce a new strategy for green, in-situ generation of silver nanoparticles using flexible and transparent bacterial cellulose nanopapers. In this method, adsorbed silver ions on bacterial cellulose nanopaper are reduced by the hydroxyl groups of cellulose nanofibers, acting as the reducing agent producing a bionanocomposite "embedded silver nanoparticles in transparent nanopaper" (ESNPs). The fabricated ESNPs were investigated and characterized by field emission scanning electron microscopy (FE-SEM), UV-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and energy-dispersive X-ray spectroscopy (EDX). The important parameters affecting the ESNPs were optimized during the fabrication of specimens. The resulting ESNPs were used as a novel and sensitive probe for the optical sensing of cyanide ion (CN(-)) and 2-mercaptobenzothiazole (MBT) in water samples with satisfactory results. The change in surface plasmon resonance absorption intensity of ESNPs was linearly proportional to the concentration in the range of 0.2-2.5 µg mL(-1) and 2-110 µg mL(-1) with a detection limit of 0.012 µg mL(-1) and 1.37 µg mL(-1) for CN(-) and MBT, respectively. PMID:26159156

  3. Highly crystalline LiCuXFe1-XPO4 nanoparticles synthesized by high temperature thermal decomposition: a morphological and electrical transport study

    Science.gov (United States)

    Martinez, P.; Ruiz, F.; Curiale, J.; Vasquez Mansilla, M.; Zysler, R. D.; Dada, L.; Moreno, M. S.; Rodríguez, L.; Fregenal, D.; Bernardi, G.; Lima, E., Jr.

    2016-08-01

    In this work, we report the morphological and electrical characterization of highly crystalline \\text{LiC}{{\\text{u}}\\text{X}}\\text{F}{{\\text{e}}1-\\text{X}}\\text{P}{{\\text{O}}4} nanoparticles synthesized via the high-temperature (380 °C) thermal decomposition of organometallic precursors. The mean diameter of the studied nanoparticles was 30-40 nm. The Cu/Fe relations of 0, 0.001 and 0.042 for the three studied samples were obtained via particle-induced x-ray emission spectroscopy. Crystallographic and morphological studies were performed using x-ray diffraction, transmission electron microscopy and high-resolution transmission electron microscopy techniques. We investigated the effects of incorporating copper on the electric transport properties of this highly crystalline nanometric system using impedance spectroscopy and DC transport techniques. The experimental evidence allowed us to conclude that in the frequency range f  <  1 kHz the transport is dominated by the diffusion of Li and the presence of Cu atoms in the systems hinders this transport mechanism, despite the high crystallinity of the system.

  4. Identifying the sources of ferromagnetism in sol-gel synthesized Zn1-xCoxO (0≤x≤0.10) nanoparticles

    Science.gov (United States)

    Beltrán, J. J.; Barrero, C. A.; Punnoose, A.

    2016-08-01

    We have carefully investigated the structural, optical and electronic properties and related them with changes in the magnetism of sol-gel synthesized Zn1-xCoxO (0≤x≤0.10) nanoparticles. Samples with x≤0.05 were free of spurious phases. Samples with x≤0.03 were found to be with only high spin Co2+ ions into ZnO structure, whereas sample with x=0.05, exhibited the presence of high spin Co2+ and low spin Co3+. We found that the intensity of the main EPR peak associated with Co2+ varies with the nominal Co content in a similar manner as the saturation magnetization and coercive field do. These results point out that the ferromagnetism in these samples should directly be correlated with the presence of divalent cobalt ions. Bound magnetic polaron (BMP) model and the charge transfer model are insufficient to explain the ferromagnetic properties of Zn1-xCoxO nanoparticles. The room temperature ferromagnetism (RTFM) may be originated from a combination of several factors such as the interaction of high spin Co2+ ions, perturbation/alteration and/or changes in the electronic structure of ZnO close to the valence band edge and grain boundary effects.

  5. The magnetic and oxidation behavior of bare and silica-coated iron oxide nanoparticles synthesized by reverse co-precipitation of ferrous ion (Fe2+) in ambient atmosphere

    Science.gov (United States)

    Mahmed, N.; Heczko, O.; Lancok, A.; Hannula, S.-P.

    2014-03-01

    The synthesis of iron oxide nanoparticles, i.e., magnetite was attempted by using only ferrous ion (Fe2+) as a magnetite precursor, under an ambient atmosphere. The room temperature reverse co-precipitation method was used, by applying two synthesis protocols. The freshly prepared iron oxide was also immediately coated with Stöber silica (SiO2) layer, forming the coreshell structure. The phase, stoichiometry, crystallite and the particle size of the synthesized powders were determined by using X-ray diffraction (XRD) and transmission electron microscope (TEM), while the magnetic and oxidation behaviors were studied by using the vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. Based on the results, the bare iron oxide nanoparticles are in the stoichiometry between the magnetite and the maghemite stoichiometry, i.e., oxidation occurs. This oxidation is depending on the synthesis protocols used. With the silica coating, the oxidation can be prevented, as suggested by the fits of Mössbauer spectra and low temperature magnetic measurement.

  6. Thermal stability and microstructure characterization of MgAl{sub 2}O{sub 4} nanoparticles synthesized by reverse microemulsion method

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Ping; Lu, Wenzhong; Lei, Wen, E-mail: lwz@mail.hust.edu.cn [Department of Electronic Science and Technology, HuaZhong University of Science and Technology - HUST, Wuhan (China); Wu, Ke; Xu, Yong [Department of Materials Science and Engineering, Wuhan Institute of Technology - WIT, Wuhan (China); Wu, Jiamin [Key Lab of Functional Materials for Electronic Information(B) MOE, HuaZhong University of Science and Technology - HUST, Wuhan (China)

    2013-11-01

    Magnesium aluminate (MgAl{sub 2}O{sub 4}) spinel nanoparticles were synthesized by reverse microemulsion process in cyclohexane by using two kinds of surfactants, n-amyl alcohol as cosurfactant and mixture of aluminic/magnesic salt aqueous solution as basic reagents. The effects of surfactant types and titration methods on the morphologies and sizes of the MgAl{sub 2}O{sub 4} nanoparticles were characterized by TEM, TGA-DTA, XRD, HR-TEM and FT-IR. TEM images show that the particles prepared by forward titration method with SPAN-80/Triton X-100 compound emulsifier have uniform spherical shape and good monodispersity with an average size of 9.5 nm. However, the average size of the particles prepared by reverse-titration method was about 10 nm and some particles have irregular plate like appearance. The products prepared with NP-40 surfactant and forward-titration method were agglomerated with an average size of 13 nm. TGA and XRD results show that the reverse microemulsion method has dramatically lowered the calcination temperature of MgAl{sub 2}O{sub 4} with a degree of 700 Degree-Sign C, and the precursor can transform to single spinel phase at 900 Degree-Sign C. (author)

  7. Dietary supplementation of green synthesized manganese-oxide nanoparticles and its effect on growth performance, muscle composition and digestive enzyme activities of the giant freshwater prawn Macrobrachium rosenbergii.

    Science.gov (United States)

    Asaikkutti, Annamalai; Bhavan, Periyakali Saravana; Vimala, Karuppaiya; Karthik, Madhayan; Cheruparambath, Praseeja

    2016-05-01

    The green synthesized Mn3O4 nanoparticles (manganese-oxide nanoparticles) using Ananas comosus (L.) peel extract was characterized by various techniques. HR-SEM photograph showed that manganese-oxide nanoparticles (Mn-oxide NPs) were spherical in shape, with an average size of 40-50nm. The Zeta potential revealed the surface charge of Mn-oxide NPs to be negative. Further, the Mn-oxide NPs were dietary supplemented for freshwater prawn Macrobrachium rosenbergii. The experimental basal diets were supplemented with Mn-oxide NPs at the rates of 0 (control), 3.0, 6.0, 9.0, 12, 15 and 18mg/kg dry feed weight. The as-supplemented Mn-oxide NPs were fed in M. rosenbergii for a period of 90 days. The experimental study demonstrated that prawns fed with diet supplemented with 3-18mg Mn-oxide NPs/kg shows enhanced (Pfeed conversion ratio (FCR) were observed in prawn fed with different diets. Additionally, prawns fed with 3.0-18mg/kg Mn-oxide NPs supplemented diets achieved significant (PCAT) metabolic enzymes status in muscle and hepatopancreas showed no significant (P>0.05) alterations in prawns fed with 3.0-18mg/kg of Mn-oxide NPs supplemented diets. Consequently, the present work proposed that 16mg/kg of Mn-oxide NPs could be supplemented for flexible enhanced survival, growth and production of M. rosenbergii. Therefore, the data of the present study recommend the addition of 16mg/kg of Mn-oxide NPs diet to developed prawn growth and antioxidant defense system. PMID:27049122

  8. Effect of Co Doping on Structural and Magnetic Properties of ZnO Nanoparticles Synthesized by Novel Combustion Synthesis

    OpenAIRE

    V. Rajendar; K. Venkateswara Rao; K. Shobhan; C.H. Shilpa Chakra

    2013-01-01

    ZnO is a wide band gap semiconductor (3.37 eV) with a high exciton binding energy (60 meV), which has wide applications in advanced optoelectronic devices. The theoretical prediction of room temperature ferromagnetism will be possible through the investigation of diluted magnetic semiconductors such as transition metal doped ZnO, especially Cobalt doped ZnO. The aim of the work is to synthesize Zn1 – xCoxO (x = 0 and x = 0.20) nanostructures through a novel urea based auto combustion method a...

  9. Transformation of biogenic carbohydrates into levulinic acid and further hydrogenation using supported nanoparticle catalysts synthesized by chemical fluid deposition

    OpenAIRE

    Yan, Kai

    2011-01-01

    The primary objective of this thesis was to synthesize and identify powerful metal catalysts and key factors for the conversion of D-fructose and D-glucose to LA as well as the hydrogenation of LA to GVL. A general overview on the use of biomass for chemicals and potential biofuel production is provided. The catalytic transformation systems developed for the conversion of biomass-derived monomers to LA and GVL are reviewed. Meanwhile, an intensive overview of the preparation of supported nano...

  10. Improved battery performance using Pd nanoparticles synthesized on the surface of LiFePO4/C by ultrasound irradiation

    Science.gov (United States)

    Saliman, Muhammad Ali; Okawa, Hirokazu; Takai, Misaki; Ono, Yuki; Kato, Takahiro; Sugawara, Katsuyasu; Sato, Mineo

    2016-07-01

    LiFePO4 has been attracting interest as a cathode material for Li-ion batteries due to its high energy density, low cost, and eco-friendliness. The electrochemical performance of LiFePO4 is limited because it exhibits low Li-ion diffusivity and low electronic conductivity. Numerous solutions have been considered, such as carbon coating, which is widely known to improve the electronic conductivity of LiFePO4. The deposition of metal nanoparticles (NPs) on the surface of carbon-coated LiFePO4 further enhances the electronic conductivity. In this study, we deposited Pd NPs onto the surface of LiFePO4/C and investigated the resulting electrochemical performance. Sonochemical synthesis was used to prepare the metal NPs; the procedure did not require any surfactants and the reaction was rapid.

  11. Removal of phosphate using iron oxide nanoparticles synthesized by eucalyptus leaf extract in the presence of CTAB surfactant.

    Science.gov (United States)

    Cao, Dan; Jin, Xiaoying; Gan, Li; Wang, Ting; Chen, Zuliang

    2016-09-01

    This study investigated the use of cetyltrimethylammonium bromide (CTAB) as a stabilizer in green synthesis to improve the reactivity of iron oxide nanoparticles (IONP). Results show that efficiency in removing phosphate increased from 71.0% to 97.3%. To understand how to improve the reactivity of IONP by CTAB: firstly, characterizations of IONP before and after phosphate removal by SEM, EDS, FTIR, XPS show the adsorption of P onto the IONP; secondly, batch experiments indicate that the adsorption capacity of phosphate increased when temperature or initial phosphate concentration increased and decreased with an increase in both adsorbent dose and pH. Adsorption followed the pseudo-second-order kinetics model and the equilibrium data fitted well to the Langmuir isotherm. Thermodynamic data confirmed the spontaneous and endothermic nature of the adsorption process. Finally, it was proposed that the adsorption of phosphate using CTAB-modified IONP was mainly associated with inner-sphere complexing mechanism and electrostatic attraction. PMID:27268791

  12. Magnetic properties of iron-oxide and (iron, cobalt)-oxide nanoparticles synthesized in polystyrene resin matrix

    Energy Technology Data Exchange (ETDEWEB)

    Naik, R. E-mail: naik@physics.wayne.edu; Kroll, E.; Rodak, D.; Tsoi, G.M.; McCullen, E.; Wenger, L.E.; Suryanarayanan, R.; Naik, V.M.; Vaishnava, P.P.; Tao, Qu; Boolchand, P

    2004-05-01

    A sulfonated polystyrene resin matrix was ion exchanged with aqueous solutions of (1) FeCl{sub 2}, (2) FeCl{sub 3}, (3) 2FeCl{sub 2}:FeCl{sub 3}, (4) 9FeCl{sub 2}:CoCl{sub 2}, and (5) 4FeCl{sub 2}:CoCl{sub 2} to prepare magnetic nanoparticles of varying size. The samples were characterized by X-ray diffraction (XRD), {sup 57}Fe Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), and identify two major phases: {gamma}-Fe{sub 2}O{sub 3}, CoFe{sub 2}O{sub 4}, and perhaps a minor Fe{sub 3}O{sub 4} phase. SQUID magnetometry measurements indicate superparamagnetic particles with blocking temperatures (T{sub B}) ranging from 20 K to room temperature.

  13. Effect of different polymers on morphology and particle size of silver nanoparticles synthesized by modified polyol method

    Science.gov (United States)

    Fereshteh, Zeinab; Rojaee, Ramin; Sharifnabi, Ali

    2016-10-01

    In this work, simple, economic, eco-friendly modified method with high efficiency was applied for synthesis of silver nanoparticles (Ag NPs) by using polyethylene glycol (PEG) as a capping agent, reductant, and media agent. In order to preparation uniform and small Ag NPs, the reaction parameters such as type of polymer, AgNO3/Polymer weight concentration ratio, and AgNO3/NaBH4 molar concentration ratio were modified. The best condition was optimized in concentration ratio of AgNO3: PEG: NaBH4 where are 1:10:0.01, respectively with 82% efficiency and 98.95% purity. Therefore, this modified polyol method can also be scaled up for synthesis of Ag NPs appropriately. Due to polymeric coating on the Ag NPs, they can be employed as a promising candidate for drug delivery systems.

  14. Characterisation and thermal properties of titanium dioxide nanoparticles-containing biodegradable polylactide composites synthesized by sol-gel method.

    Science.gov (United States)

    Mhlanga, Nikiwe; Ray, Suprakas Sinha

    2014-06-01

    This study reports the synthesis, characterisation and thermal properties of polylactide (PLA)/titanium dioxide nanoparticles (TiO2 NPs) composites using the sol-gel method. The percentage weight of TiO2 NP sol was varied from 3, 8, 11 and 14. The synthesised composites were characterised using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis and dynamic mechanical analysis. Encapsulation of the TiO2 into the PLA matrix was attainable based on the SEM images and the FTIR and EDS results. The thermal stability of the composites was shifted to lower temperatures due to photodegradation induced by the metal oxide on the PLA chain. Both PLA and TiO2 NPs have potential in drug delivery because of their biocompatibility and biodegradability. PMID:24738382

  15. Physical, electrical and dielectric properties of Ca-substituted strontium hexaferrite (SrFe{sub 12}O{sub 19}) nanoparticles synthesized by co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Javed Iqbal, Muhammad, E-mail: mjiqauchem@yahoo.co [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University Islamabad-45320 (Pakistan); Naeem Ashiq, Muhammad [Department of Chemistry, Bahauddin Zakariya University, Multan (Pakistan); Hussain Gul, Iftikhar [School of Chemical and Materials Engineering, National University of Science and Technology (NUST), Islamabad (Pakistan)

    2010-07-15

    Calcium substituted strontium hexaferrite Ca{sub x}Sr{sub 1-x}Fe{sub 12}O{sub 19} (x=0.0-0.6) nanoparticles are synthesized by chemical co-precipitation method. The synthesized samples are characterized by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy, Transmission Electron Microscopy, DC electrical resistivity and dielectric measurements. FTIR data of uncalcined sample shows that nitrate ions are present which disappeared on calcination at 920 deg. C. The XRD data shows that a single hexagonal magnetoplumbite phase is formed in samples in which the calcium content, x, is <=0.20. However, a nonmagnetic phase (alpha-Fe{sub 2}O{sub 3}) in addition to the hexagonal phase is also present in samples with x>0.20. The average crystallite size is found between 17 and 29 nm. The DC electrical resistivity increases with increase of calcium content up to level of x=0.2 but decreased on further addition of calcium. The enhanced resistivity of the calcium doped material has potential applications in microwave devices. The variations of dielectric constant and dielectric loss angle are explained on the basis of Maxwell-Wagner and Koops models.

  16. Comparison of Urea and Citric Acid Complexing Agents and Annealing Temperature Effect on the Structural Properties of - and -Alumina Nanoparticles Synthesized by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    A. Rajaeiyan

    2013-01-01

    Full Text Available A sol-gel method based on the Pechini process was used to synthesize different phases of alumina nanoparticles using a polymeric precursor with Aluminum nitrate. The emphasis was on investigating the effect of two different complexing agents, urea and citric acid, on the structural properties, particle size, and phase transformation during the heat treatment that was studied by XRD, TEM, SEM, BET, and FT-IR spectroscopy. The obtained results showed that particles do get fused together at high temperatures, and also the size of particles increases with the increase of annealing temperature. It was concluded that the size of α-alumina synthesized by urea was 10–15 nm, whereas the sample with citric acid yielded α-powder with particle size of 200 nm. Also, the resulting powder prepared by urea exhibited larger surface area (84.2 m2/gm−1 compared to citric acid (39.92 m2/gm−1 at .

  17. Effect of hydrolysis ratio on structural, optical and electrical properties of SnO2 nanoparticles synthesized by polyol method

    Science.gov (United States)

    Soltan, Wissem Ben; Mbarki, Mourad; Bargougui, Radhouane; Ammar, Salah; Babot, Odile; Toupance, Thierry

    2016-08-01

    Using the polyol method and a thermal post-treatment, nanoporous tin dioxide (SnO2) were prepared at different hydrolysis ratio (h = n (H2O)/n (Sn)). The influence of the hydrolysis ratio on the structural, textural, optical and electrical properties of SnO2 nanopowders was investigated by employing a set of various techniques including Fourier Transform Infra-Red spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM), Nitrogen Sorption Porosimetry and Impedance Spectroscopy. FTIR and EDX studies revealed that SnO2 species were obtained. Nanocrystallites of cassiterite, i.e. rutile-like tetragonal SnO2 structure, were formed after annealing in air at 700 °C and the average crystallite size increased from 12.8 to 29.1 when the hydrolysis ratio rose from 17 to 24. Moreover, TEM, SEM, and N2 sorption porosimetry investigations indicated that the sample prepared for h = 17 was composed of an aggregated network of almost spherical nanoparticles, the morphology and sizes of which changed with the increase in the hydrolysis ratio to h = 24 and the mesoporosity of which was found to be linked to the interparticle space. Moreover, this increase in mean nanoparticle size was accompanied by a decrease in the band gap value from 3.4 eV (h = 17) to 3.16 eV (h = 24). Finally, bulk conductivity dependence with temperature was found to follow an Arrhenius law for samples annealed at 700 °C with an activation energy of 0.65 eV for h = 17, 0.69 eV for h = 20 and 0.71 eV for h = 24 that is typical of SnO2 nanopowders.

  18. The optical band gap investigation of PVP-capped ZnO nanoparticles synthesized by sol-gel method

    Science.gov (United States)

    Yuliah, Yayah; Bahtiar, Ayi; Fitrilawati, Siregar, Rustam E.

    2016-02-01

    ZnO Nanoparticles (NPs) has unique natures on their crystal structure, direct band gap and high exciton binding energy, consequently applied in optoelectronic devices such as solar cells, optical wave guide and light emitting diodes (LED). However the drawback was ZnO NPs tend to agglomerate and turn to nano-structured materials with poor properties. Effort to avoid agglomerations generally resolved by surface modification of ZnO NPs to obtain well-dispersed suspension. However changes in the surface of ZnO NPs may change the electronic structure and density of states of ZnO NPs, in turn may change the optical band gap. Thus, the objective of current research is investigation of optical band gap of ZnO NPs due to surface modification by capping agent of poly-4-vinylpyrrolidone (PVP) molecules. Uncapped and PVP-capped ZnO nanoparticles were prepared by sol-gel method. The characteristics of surface modifications were investigated by UV-Vis and Photo Luminescence spectroscopy and Transmission Electron Microscope (TEM). The results shows the surface modification has change the band gap of ZnO NPs obtained at second precipitated stage. In contrast, the change of the optical band gap did not observe due to the surface modification of ZnO NPs obtained at the first stage. It was concluded that PVP capping on ZnO NPs did not affect on the band gap when the capping was performed on first stage. It is emphasized that this statement also supported by TEM images observations.

  19. Microstructural, structural and optical properties of nanoparticles of PbO-CrO3 pigment synthesized by a soft route

    Directory of Open Access Journals (Sweden)

    V. D. Araújo

    2015-03-01

    Full Text Available PbCrO4 and Pb2CrO5 particles were synthesized by the polymeric precursor method. Structural and microstructural properties of the particles were characterized by scanning electron microscopy with field emission gun, X-ray diffraction, and Raman spectroscopy techniques. The diffuse reflectance technique was employed to study the optical properties in the 400-700 nm range. The optical bandgap of the samples was obtained indirectly. Colorimetric coordinates L*, a*, b* were calculated for the pigment powders as a function of the heat treatment (400-700 ºC. The powders displayed colors ranging from green to red. X-ray diffraction patterns showed the presence of monoclinic PbCrO4 phase in green samples, while red powders had a monoclinic Pb2CrO5 phase structure. The Raman spectra of the PbCrO4 and Pb2CrO5 powders were in good agreement with those reported in the literature. The synthesized compounds can be used as green and red pigments with high thermal stability.

  20. Mössbauer and magnetization studies of nickel ferrite nanoparticles synthesized by the microwave-combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, M.H.; Elshahawy, A.M. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Makhlouf, Salah A., E-mail: smakhlouf@gmail.com [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Deanship of Scientific Research, Al Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11463 (Saudi Arabia); Hamdeh, H.H. [Department of Physics, Wichita State University, Wichita, KS (United States)

    2013-10-15

    Nanocrystalline nickel ferrite was synthesized from its stoichiometric metal nitrates and urea mixtures, using a microwave assisted combustion method. The process was a convenient, inexpensive and an efficient method for formation of NiFe{sub 2}O{sub 4} nanomaterials. Effect of urea/metal nitrates ratio on the obtained phases, particle size and magnetic properties has been investigated by various techniques. Saturation magnetization of 50 emu/g was observed at room temperature for larger particles, and it decreases with decreasing particle size. The coercivity attains a maximum value of 170 Oe when the particle size was ∼20 nm, and decreases with increasing particle size. Mössbauer spectra measured at RT for some representative samples show a combination of ordered and superparamagnetic behavior, whereas those collected at 20 K elucidate the nature of the obtained phases and cation distribution. - Highlights: • Nanosized Ni ferrite was synthesized by a microwave assisted combustion method. • The particle size was controlled by changing the urea/metal nitrate ratio. • Magnetization and coercive field vary with particle size. • Mössbauer spectra elucidate the nature of the phases and cation distribution.

  1. Characterization and biotoxicity of Hypnea musciformis-synthesized silver nanoparticles as potential eco-friendly control tool against Aedes aegypti and Plutella xylostella.

    Science.gov (United States)

    Roni, Mathath; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Nicoletti, Marcello; Madhiyazhagan, Pari; Dinesh, Devakumar; Suresh, Udaiyan; Khater, Hanem F; Wei, Hui; Canale, Angelo; Alarfaj, Abdullah A; Munusamy, Murugan A; Higuchi, Akon; Benelli, Giovanni

    2015-11-01

    Two of the most important challenges facing humanity in the 21st century comprise food production and disease control. Eco-friendly control tools against mosquito vectors and agricultural pests are urgently needed. Insecticidal products of marine origin have a huge potential to control these pests. In this research, we reported a single-step method to synthesize silver nanoparticles (AgNP) using the aqueous leaf extract of the seaweed Hypnea musciformis, a cheap, nontoxic and eco-friendly material, that worked as reducing and stabilizing agent during the biosynthesis. The formation of AgNP was confirmed by surface plasmon resonance band illustrated in UV-vis spectrophotometer. AgNP were characterized by FTIR, SEM, EDX and XRD analyses. AgNP were mostly spherical in shape, crystalline in nature, with face-centered cubic geometry, and their mean size was 40-65nm. Low doses of H. musciformis aqueous extract and seaweed-synthesized AgNP showed larvicidal and pupicidal toxicity against the dengue vector Aedes aegypti and the cabbage pest Plutella xylostella. The LC50 value of AgNP ranged from 18.14 to 38.23ppm for 1st instar larvae (L1) and pupae of A. aegypti, and from 24.5 to 38.23ppm for L1 and pupae of P. xylostella. Both H. musciformis extract and AgNP strongly reduced longevity and fecundity of A. aegypti and P. xylostella adults. This study adds knowledge on the toxicity of seaweed borne insecticides and green-synthesized AgNP against arthropods of medical and agricultural importance, allowing us to propose the tested products as effective candidates to develop newer and cheap pest control tools.

  2. Multidimensional effects of biologically synthesized silver nanoparticles in Helicobacter pylori, Helicobacter felis, and human lung (L132) and lung carcinoma A549 cells

    Science.gov (United States)

    Gurunathan, Sangiliyandi; Jeong, Jae-Kyo; Han, Jae Woong; Zhang, Xi-Feng; Park, Jung Hyun; Kim, Jin-Hoi

    2015-02-01

    Silver nanoparticles (AgNPs) are prominent group of nanomaterials and are recognized for their diverse applications in various health sectors. This study aimed to synthesize the AgNPs using the leaf extract of Artemisia princeps as a bio-reductant. Furthermore, we evaluated the multidimensional effect of the biologically synthesized AgNPs in Helicobacter pylori, Helicobacter felis, and human lung (L132) and lung carcinoma (A549) cells. UV-visible (UV-vis) spectroscopy confirmed the synthesis of AgNPs. X-ray diffraction (XRD) indicated that the AgNPs are specifically indexed to a crystal structure. The results from Fourier transform infrared spectroscopy (FTIR) indicate that biomolecules are involved in the synthesis and stabilization of AgNPs. Dynamic light scattering (DLS) studies showed the average size distribution of the particle between 10 and 40 nm, and transmission electron microscopy (TEM) confirmed that the AgNPs were significantly well separated and spherical with an average size of 20 nm. AgNPs caused dose-dependent decrease in cell viability and biofilm formation and increase in reactive oxygen species (ROS) generation and DNA fragmentation in H. pylori and H. felis. Furthermore, AgNPs induced mitochondrial-mediated apoptosis in A549 cells; conversely, AgNPs had no significant effects on L132 cells. The results from this study suggest that AgNPs could cause cell-specific apoptosis in mammalian cells. Our findings demonstrate that this environmentally friendly method for the synthesis of AgNPs and that the prepared AgNPs have multidimensional effects such as anti-bacterial and anti-biofilm activity against H. pylori and H. felis and also cytotoxic effects against human cancer cells. This report describes comprehensively the effects of AgNPs on bacteria and mammalian cells. We believe that biologically synthesized AgNPs will open a new avenue towards various biotechnological and biomedical applications in the near future.

  3. Flower-shaped ZnO nanoparticles synthesized by a novel approach at near-room temperatures with antibacterial and antifungal properties

    Directory of Open Access Journals (Sweden)

    Khan MF

    2014-02-01

    Full Text Available Mohd Farhan Khan,1,2 M Hameedullah,1 Akhter H Ansari,1 Ejaz Ahmad,3 MB Lohani,2 Rizwan Hasan Khan,3 M Mezbaul Alam,4 Wasi Khan,5 Fohad Mabood Husain,6 Iqbal Ahmad6 1NanoSolver Lab, Department of Mechanical Engineering, Zakir Hussain College of Engineering and Technology, Aligarh Muslim University, Aligarh, India; 2Department of Applied Chemistry, Integral University, Lucknow, India; 3Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India; 4Chemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 5Centre of Excellence in Materials Science (Nanomaterials, Department of Applied Physics, Zakir Hussain College of Engineering and Technology, Aligarh Muslim University Aligarh, India; 6Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, India Abstract: Due to enormous applications of metal oxide nanoparticles in research and health-related applications, metal oxide nanoparticles are increasingly being developed through cheaper and more user-friendly approaches. We have formulated a simple route to synthesize zinc oxide nanoparticles (ZNPs by a sol–gel method at near-room temperatures 25°C, 35°C, 55°C, and 75°C. The results are analyzed by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and ultraviolet-visible absorption spectroscopy. The effect of different temperature conditions (25°C–75°C on the particulate sizes (23.7–88.8 nm, pH levels (11.7–11.9, and morphologies (slender needle–broad arrow of flower-shaped ZNP colonies is studied. A possible mechanism depicting the growth rates at different temperatures and of different facets, mainly towards the <0 0 0 I> and <0 I Ī0> planes of the ZNPs has also been discussed. The values of λmax (293–298 nm suggest that ZNPs prepared at 55°C are the most effective ultraviolet B absorbers, and that they can be used in sunscreens

  4. In situ synthesized BSA capped gold nanoparticles: effective carrier of anticancer drug methotrexate to MCF-7 breast cancer cells.

    Science.gov (United States)

    Murawala, Priyanka; Tirmale, Amruta; Shiras, Anjali; Prasad, B L V

    2014-01-01

    The proficiency of MTX loaded BSA capped gold nanoparticles (Au-BSA-MTX) in inhibiting the proliferation of breast cancer cells MCF-7 as compared to the free drug Methotrexate (MTX) is demonstrated based on MTT and Ki-67 proliferation assays. In addition, DNA ladder gel electrophoresis studies, flow cytometry and TUNEL assay confirmed the induction of apoptosis by MTX and Au-BSA-MTX in MCF-7 cells. Notably, Au-BSA-MTX was found to have higher cytotoxicity on MCF-7 cells compared with an equivalent dose of free MTX. The enhanced activity is attributed to the preferential uptake of Au-BSA-MTX particles by MCF-7 cells due to the presence of BSA that acts as a source of nutrient and energy to the rapidly proliferating MCF-7 cells. Moreover, the targeting ability of the drug MTX to the over expressed folate receptors on MCF-7 cells also contributes to the enhanced uptake and activity. Taken together, these results unveil that Au-BSA-MTX could be more effective than free drug for cancer treatment.

  5. The impact of the confinement of reactants on the metal distribution in bimetallic nanoparticles synthesized in reverse micelles

    Directory of Open Access Journals (Sweden)

    Concha Tojo

    2014-11-01

    Full Text Available A kinetic study on the formation of bimetallic nanoparticles in microemulsions was carried out by computer simulation. A comprehensive analysis of the resulting nanostructures was performed regarding the influence of intermicellar exchange on reactivity. The objects of this study were metals having a difference in standard reduction potential of about 0.2–0.3 V. Relatively flexible microemulsions were employed and the concentration of the reactants was kept constant, while the reaction rate of each metal was monitored as a function of time using different reactant proportions. It was demonstrated that the reaction rates depend not only on the chemical reduction rate, but also on the intermicellar exchange rate. Furthermore, intermicellar exchange causes the accumulation of slower precursors inside the micelles, which favors chemical reduction. As a consequence, slower reduction rates strongly correlate with the number of reactants in this confined media. On the contrary, faster reduction rates are limited by the intermicellar exchange rate and not the number of reactants inside the micelles. As a result, different precursor proportions lead to different sequences of metal reduction, and thus the arrangement of the two metals in the nanostructure can be manipulated.

  6. Formic acid electro-oxidation at PtAu alloyed nanoparticles synthesized by pulsed laser ablation in liquids

    Science.gov (United States)

    Oko, Daniel Nii; Zhang, Jianming; Garbarino, Sébastien; Chaker, Mohamed; Ma, Dongling; Tavares, Ana C.; Guay, Daniel

    2014-02-01

    A series of mono dispersed PtxAu100-x alloy nanoparticles (NPs), with x varying from 0 to 100, were prepared by pulsed laser ablation in liquids, using a series of targets that were made by mixing pure Pt and pure Au powders. The structures of PtxAu100-x alloy NPs were assessed by transmission electron microscopy and X-ray diffraction. A face-centered solid solution is obtained over the whole composition range, and the particle size increases from 2.5 to 5.3 nm as x is increased from 0 to 100. The electrocatalytic performances of the PtxAu100-x alloy NPs towards the formic acid oxidation were investigated by cyclic voltammetry and chronoamperometry. On as-prepared PtxAu100-x alloy NPs, oxidation of formic acid occurs through dehydrogenation, while dehydration is the privileged mechanism on as-prepared mixtures of Pt and Au NPs. However, after a series of CV in 0.5 M H2SO4, both types of catalysts are able to oxidize formic acid according to the dehydrogenation pathway. After 600 s of electrolysis, the mass activities of PtxAu100-x alloy NPs is a factor of two larger than that of mixtures of pure Pt and pure Au NPs with the same surface composition, although both types of catalysts display similar activity with respect to the total electrochemically active surface area.

  7. Linear sweep anodic stripping voltammetry: Determination of Chromium (VI) using synthesized gold nanoparticles modified screen-printed electrode

    Indian Academy of Sciences (India)

    Salamatu Aliyu Tukur; Nor Azah Yusof; Reza Hajian

    2015-06-01

    A highly sensitive electrochemical sensor has been constructed for determination of Cr(VI) with the lowest limit of detection (LOD) reported to date using gold nanoparticles (AuNPs) modified screen-printed electrode (SPE). The modification of SPE by casting pure AuNPs increases the sensitivity for detection of Cr(VI) ion using anodic stripping voltammetry. Cr(VI) ions are reduced to chromium metal on SPE-AuNPs by applying deposition potential of –1.1 V for 180 s. Afterwards, the oxidation peak current of chromium is obtained by linear sweep voltammetry in the range of −1.0 V to 0.2 V. Under the optimized conditions (HClO4, 0.06 mol L−1; deposition potential, –1.1 V; deposition time, 180s; scan rate, 0.1 V s−1), the limit of detection (LOD) was 1.6 pg mL−1. The fabricated electrode was successfully used for detection of Cr(VI) in tap and seawater.

  8. Mosquito larvicidal potential of silver nanoparticles synthesized using Chomelia asiatica (Rubiaceae) against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Muthukumaran, Udaiyan; Govindarajan, Marimuthu; Rajeswary, Mohan

    2015-03-01

    Mosquitoes transmit serious human diseases, causing millions of deaths every year. Mosquito control is to enhance the health and quality of life of county residents and visitors through the reduction of mosquito populations. Mosquito control is a serious concern in developing countries like India due to the lack of general awareness, development of resistance, and socioeconomic reasons. Today, nanotechnology is a promising research domain which has a wide ranging application in vector control programs. These are nontoxic, easily available at affordable prices, biodegradable, and show broad-spectrum target-specific activities against different species of vector mosquitoes. In the present study, larvicidal activity of aqueous leaf extract and silver nanoparticles (AgNPs) synthesized using C. asiatica plant leaves against late third instar larvae of Anopheles stephensi, Aedes aegypti, and Cx. quinquefasciatus. The range of varying concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg/mL) and aqueous leaf extract (40, 80, 120, 160, and 200 μg/mL) were tested against the larvae of An. stephensi, Ae. aegypti, and Cx. quinquefasciatus. The synthesized AgNPs from C. asiatica were highly toxic than crude leaf aqueous extract in three important vector mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis (EDX). Considerable mortality was evident after the treatment of C. asiatica for all three important vector mosquitoes. The LC50 and LC90 values of C. asiatica aqueous leaf extract appeared to be effective against An. stephensi (LC50, 90.17 μg/mL; LC90, 165.18 μg/mL) followed by Ae. aegypti (LC50, 96.59 μg/mL; LC90, 173.83 μg/mL) and Cx. quinquefasciatus (LC50, 103.08 μg/mL; LC90, 183.16 μg/mL). Synthesized AgNPs against the vector mosquitoes of An. stephensi, Ae. aegypti, and Cx. quinquefasciatus had the following LC50 and LC90

  9. Seaweed-synthesized silver nanoparticles: an eco-friendly tool in the fight against Plasmodium falciparum and its vector Anopheles stephensi?

    Science.gov (United States)

    Murugan, Kadarkarai; Samidoss, Christina Mary; Panneerselvam, Chellasamy; Higuchi, Akon; Roni, Mathath; Suresh, Udaiyan; Chandramohan, Balamurugan; Subramaniam, Jayapal; Madhiyazhagan, Pari; Dinesh, Devakumar; Rajaganesh, Rajapandian; Alarfaj, Abdullah A; Nicoletti, Marcello; Kumar, Suresh; Wei, Hui; Canale, Angelo; Mehlhorn, Heinz; Benelli, Giovanni

    2015-11-01

    Malaria, the most widespread mosquito-borne disease, affects 350-500 million people each year. Eco-friendly control tools against malaria vectors are urgently needed. This research proposed a novel method of plant-mediated synthesis of silver nanoparticles (AgNP) using a cheap seaweed extract of Ulva lactuca, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The U. lactuca extract and the green-synthesized AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi. In mosquitocidal assays, LC50 values of U. lactuca extract against A. stephensi larvae and pupae were 18.365 ppm (I instar), 23.948 ppm (II), 29.701 ppm (III), 37.517 ppm (IV), and 43.012 ppm (pupae). LC50 values of AgNP against A. stephensi were 2.111 ppm (I), 3.090 ppm (II), 4.629 ppm (III), 5.261 ppm (IV), and 6.860 ppm (pupae). Smoke toxicity experiments conducted against mosquito adults showed that U. lactuca coils evoked mortality rates comparable to the permethrin-based positive control (66, 51, and 41%, respectively). Furthermore, the antiplasmodial activity of U. lactuca extract and U. lactuca-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. Fifty percent inhibitory concentration (IC50) values of U. lactuca were 57.26 μg/ml (CQ-s) and 66.36 μg/ml (CQ-r); U. lactuca-synthesized AgNP IC50 values were 76.33 μg/ml (CQ-s) and 79.13 μg/ml (CQ-r). Overall, our results highlighted out that U. lactuca-synthesized AgNP may be employed to develop newer and safer agents for malaria control.

  10. Larvicidal activity of silver nanoparticles synthesized using Pergularia daemia plant latex against Aedes aegypti and Anopheles stephensi and nontarget fish Poecillia reticulata.

    Science.gov (United States)

    Patil, Chandrashekhar D; Borase, Hemant P; Patil, Satish V; Salunkhe, Rahul B; Salunke, Bipinchandra K

    2012-08-01

    In present study, the bioactivity of latex-producing plant Pergularia daemia as well as synthesized silver nanoparticles (AgNPs) against the larval instars of Aedes aegypti and Anopheles stephensi mosquito larvae was determined. The range of concentrations of plant latex (1,000, 500, 250, 125, 62.25, and 31.25 ppm) and AgNPs (10, 5, 2.5, 1.25, 0.625, and 0.3125 ppm) were prepared. The LC(50) and LC(90) values for first, second, third, and fourth instars of synthesized AgNPs-treated first, second, third, and fourth instars of A. aegypti (LC(50) = 4.39, 5.12, 5.66, 6.18; LC(90) = 9.90, 11.13, 12.40, 12.95 ppm) and A. stephensi (LC(50) = 4.41, 5.35, 5.91, 6.47; LC(90) = 10.10, 12.04, 13.05, 14.08 ppm) were found many fold lower than crude latex-treated A. aegypti (LC(50) = 55.13, 58.81, 75.66, 94.31; LC(90) = 113.00, 118.25, 156.95, 175.71 ppm) and A. stephensi (LC(50) = 81.47, 92.09, 96.07, 101.31; LC(90) = 159.51, 175.97, 180.67, 190.42 ppm). The AgNPs did not exhibit any noticeable effects on Poecillia reticulata after either 24 or 48 h of exposure at their LC(50) and LC(90) values against fourth-instar larvae of A. aegypti and A. stephensi. The UV-visible analysis shows absorbance for AgNPs at 520 nm. TEM reveals spherical shape of synthesized AgNPs. Particle size analysis revealed that the size of particles ranges from 44 to 255 nm with average size of 123.50 nm. AgNPs were clearly negatively charged (zeta potential -27.4 mV). This is the first report on mosquito larvicidal activity P. daemia-synthesized AgNPs.

  11. Structural studies of mechano-chemically synthesized CuIn1-xGaxSe2 nanoparticles

    International Nuclear Information System (INIS)

    CuInGaSe2 is a I-III-VI2 semiconducting material of tetragonal chalcopyrite structure. It is a very prominent absorber layer for photovoltaic devices. Particle-based coating process for CIGS is considered to be promising technique with relatively simple procedures and low initial investment. In the present work CIGS nanoparticle precursors suitable for screen-printing ink has been prepared by ball milling. High purity elemental copper granules, selenium and indium powders and fine chips of gallium were used as starting materials. First the ball milling was carried out for CuIn1-xGaxSe2 (x = 0.5) with (i) 10 ml of ethyl alcohol (ii) 5 ml of tetra ethylene glycol (wet) and (iii) 1 ml of ethylene diamine (semi-dry) for a milling time of 3 h and the results are not stoichiometric. In order to obtain an improved stoichiometric composition dry ball milling of elemental sources for three different compositions of CuIn1-xGaxSe2 (x = 0.25, 0.5 and 0.75) has been carried out. X-ray diffraction analysis revealed the presence of (1 1 2), (2 2 0)/(2 0 4), (3 1 2)/(1 1 6), (4 0 0) and (3 3 2) reflections for all the milled powders. These reflections correspond to chalcopyrite structure of CIGS. Shift in peaks towards higher value of 2θ is observed with the increase in Ga composition. Average grain size calculated by Scherrer's formula is found to be around 13 nm for the dry samples milled for 1.5 h and 7-8 nm for the samples wet milled for 3 h. Lattice constants 'a' and 'c' are found to decrease with the increase in concentration of Gallium. FESEM analysis revealed a strong agglomeration of the particles and the particle size varied from 11 to 30 nm for the dry-milled samples. Composition of milled powders has been studied by energy dispersive X-ray analysis. TEM analysis revealed the presence of nanocrystalline particles and SAED pattern corresponds to (1 1 2), (2 2 0)/(2 0 4), (5 1 2)/(4 1 7) and (6 2 0)/(6 0 4) diffraction peaks of CIGS. From the HRTEM analysis the d

  12. High-value utilization of lignin to synthesize Ag nanoparticles with detection capacity for Hg²⁺.

    Science.gov (United States)

    Shen, Zuguang; Luo, Yuqiong; Wang, Qun; Wang, Xiaoying; Sun, Runcang

    2014-09-24

    This study reports the rapid preparation of silver nanoparticles (AgNPs) from Tollens' reagent under microwave irradiation. In the synthesis, lignin with reducing groups and spatial three-dimensional structure was used as reducing and stabilizing agents without other chemical reagents, and the effects of the ratio of lignin to Ag(+), reaction temperature, and heating time on the synthesis of AgNPs were investigated. The obtained AgNPs were further characterized by UV-vis, Malvern particle size, TEM, XRD, and XPS analyses. The structural changes of lignin before and after reaction were also studied by FT-IR, (1)H NMR, (13)C NMR, and GC-MS. The results revealed that the obtained AgNPs were mostly spherical with diameters of around 24 nm. The optimum reaction conditions were a ratio 50 mg of lignin to 0.3 mM of Ag(+), a microwave irradiation temperature of 60 °C, and a heating time of 10 min. Moreover, AgNPs redispersed well in water and ethanol after centrifugation for the removal of lignin. During the formation of AgNPs, lignin was oxidized, and the side chains of lignin were partly disrupted into small molecules, such as hydrocarbon and alcohol. The resultant lignin-AgNPs showed highly selective sensing detection for Hg(2+), and the color of the lignin-AgNP solution containing Hg(2+) decreased gradually with increasing amounts of Hg(2+) within seconds, but the other 19 metal ions had little effect on the color and surface plasmon absorption band of the lignin-AgNPs. Also, there was a linear relationship between the absorbance and Hg(2+) concentration, with a limit of detection concentration of 23 nM. This study provides not only a new way to take advantage of agricultural and forestry residues, but also a green and rapid method for the synthesis of AgNPs to detect the toxic ion Hg(2+) selectively and sensitively.

  13. Distinction between SnO2 nanoparticles synthesized using co-precipitation and solvothermal methods for the photovoltaic efficiency of dye-sensitized solar cells

    Indian Academy of Sciences (India)

    M M Rashad; I A Ibrahim; I Osama; A E Shalan

    2014-06-01

    Nanocrystalline SnO2 powders prepared by solvothermal and co-precipitation pathways have been characterized using XRD, TEM, UV–Visible absorption, BET specific surface area (BET) method, EIS and – measurements. The obtained powders have a surface area and size of 38.59 m2/g and 10.63 nm for the SnO2 powders synthesized solvothermally at a temperature of 200 °C for 24 h, while the values were 32.59 m2/g and 16.20 nm for the formed hydroxide precursor annealed at 1000 °C for 2 h by co-precipitation route. The microstructure of the formed powders appeared as tetragonal-like structure. Thus, the prepared SnO2 nanopowders using two pathways were applied as an electrode in dye-sensitized solar cell (DSSC). The photoelectrochemical measurements indicated that the cell presents short-circuit photocurrent (sc), open circuit voltage (oc) and fill factor (FF) were 7.017 mA/cm2, 0.690 V and 69.68%, respectively, for solvothermal route and they were 4.241 mA/cm2, 0.756 V and 66.74%, respectively, for co-precipitation method. The energy conversion efficiency of the solvothermal SnO2 powders was considerably higher than that formed by co-precipitation powders; ∼ 3.20% (solvothermal) and 2.01% (co-precipitation) with the N719 dye under 100 mW/cm2 of simulated sunlight, respectively. These results were in agreement with EIS study showing that the electrons were transferred rapidly to the surface of the solvothermal-modified SnO2 nanoparticles, compared with that of a co-precipitation-modified SnO2 nanoparticles.

  14. Characterization of mechano-thermally synthesized Curie temperature-adjusted La0.8Sr0.2MnO3 nanoparticles coated with (3-aminopropyl) triethoxysilane

    International Nuclear Information System (INIS)

    This research aimed to synthesize nanostructured strontium-doped lanthanum manganite, La0.8Sr0.2MnO3 (LSMO), with its Curie temperature (Tc) adjusted to the therapeutic range, through a mechanothermal route. In order to investigate the effect of heat treatment temperature and duration on the resulting crystallite size, morphology, magnetic behavior and Curie temperature, the starting powder mixture was milled in a planetary ball mill before being subsequently heat treated at distinct temperatures for different time lengths. The composition, morphology, and magnetic behavior were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and vibrating sample magnetometer (VSM). In addition, magnetic properties were further investigated using an alternating current (AC) susceptometer and thermo-magnetic analyzer. 20 h of milling produced a crystallite size reduction leading to a decrease in the heat treatment temperature of LSMO synthesis to 800 °C. Moreover, SEM analysis has shown the morphology of a strong agglomeration of fine nanoparticles. HRTEM showed clear lattice fringes of high crystallinity. The mean crystallite and particle size of 20-hour milled sample heat treated at 1100 °C for 10 h are relatively 69 and 100 nm, respectively. The VSM data at room temperature, indicated a paramagnetic behavior for samples heat treated at 800 °C. However, by increasing heat treatment temperature to 1100 °C, LSMO indicates a ferromagnetic behavior with well-adjusted Curie temperature of 320 K, suitable for hyperthermia applications. Also, reentrant spin glass (RSG) behavior has been found in heat treated samples. The particles are coated with (3-aminopropyl) triethoxysilane (APTES) for biocompatibility purposes; Fourier transform infrared spectroscopy (FTIR) and thermo-gravimetric analysis (TGA) are used for

  15. Verification of resistance to three mediated microbial strains and cancerous defense against MCF7 compared to HepG2 through microwave synthesized plant-mediated silver nanoparticle

    Science.gov (United States)

    Abdel-Fattah, W. I.; Eid, M. M.; Hanafy, M. F.; Hussein, M.; Abd El-Moez, Sh I.; El-Hallouty, S. M.; Mohamed, E.

    2015-09-01

    The antimicrobial and anticancer efficiencies of green synthesized silver nanoparticles (AgNPs) through biogenic extracts were assessed on three bacterial strains and two cancer cell lines. Bio-synthesized AgNPs were achieved through domestic microwave generator for obtaining extracts from Asian nuts and Egyptian blackberry fruits. Surface plasmon resonance (SPR) ˜435 nm demonstrated AgNPs earlier formation by the fruit extract. Capping by triglycerides/almond and phenols/berry extracts were responsible for the reduction proved by FTIR. XRD calculated particle sizes were 18 and 42 nm while TEM sizes are 24.5 and 21.5 nm for AgNPs from almond nut and blackberry fruits extracts (Alm.N.Ext. and BB.F.Ext.), respectively. Ag 3d5/2 was recorded at 368.12 eV for both samples through XPS. The monodispersed AgNPs recorded 0.727 and 0.5 polydispersity indices (PdI) for almond/Ag and berry/Ag, respectively. Zeta potential ˜ -31 and -13.2 for the same sequence confirmed the higher stability of the former. Reaction kinetics confirmed the advantage of fruit extract consuming only six minutes compared to nuts, consuming twice. Bactericidal effect of the extracts seldomly presented remarkable inhibition compared to extracts/Ag against the three species. In addition, Alm.N.Ext. showed the highest inhibition against staphylococcus aureus (S. aureus) at 4 mM. The anti-cancerous effect of Ag/berry against HepG2 is stronger than Ag/almond, and similarly for MCF7.

  16. Green-synthesized silver nanoparticles as a novel control tool against dengue virus (DEN-2) and its primary vector Aedes aegypti.

    Science.gov (United States)

    Sujitha, Vasu; Murugan, Kadarkarai; Paulpandi, Manickam; Panneerselvam, Chellasamy; Suresh, Udaiyan; Roni, Mathath; Nicoletti, Marcello; Higuchi, Akon; Madhiyazhagan, Pari; Subramaniam, Jayapal; Dinesh, Devakumar; Vadivalagan, Chithravel; Chandramohan, Balamurugan; Alarfaj, Abdullah A; Munusamy, Murugan A; Barnard, Donald R; Benelli, Giovanni

    2015-09-01

    Dengue is an arthropod-borne viral infection mainly vectored through the bite of Aedes mosquitoes. Recently, its transmission has strongly increased in urban and semi-urban areas of tropical and sub-tropical regions worldwide, becoming a major international public health concern. There is no specific treatment for dengue. Its prevention and control solely depends on effective vector control measures. In this study, we proposed the green-synthesis of silver nanoparticles (AgNP) as a novel and effective tool against the dengue serotype DEN-2 and its major vector Aedes aegypti. AgNP were synthesized using the Moringa oleifera seed extract as reducing and stabilizing agent. AgNP were characterized using a variety of biophysical methods including UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and sorted for size categories. AgNP showed in vitro antiviral activity against DEN-2 infecting vero cells. Viral titer was 7 log10 TCID50/ml in control (AgNP-free), while it dropped to 3.2 log10 TCID50/ml after a single treatment with 20 μl/ml of AgNP. After 6 h, DEN-2 yield was 5.8 log10 PFU/ml in the control, while it was 1.4 log10 PFU/ml post-treatment with AgNP (20 μl/ml). AgNP were highly effective against the dengue vector A. aegypti, with LC50 values ranging from 10.24 ppm (I instar larvae) to 21.17 ppm (pupae). Overall, this research highlighted the concrete potential of green-synthesized AgNP in the fight against dengue and its primary vector A. aegypti. Further research on structure-activity relationships of AgNP against other dengue serotypes is urgently required. PMID:26063530

  17. Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO2 reforming of methane

    KAUST Repository

    Biausque, Gregory

    2015-09-24

    Embodiments of the present disclosure provide for NiPt nanoparticles, compositions and supports including NiPt nanoparticles, methods of making NiPt nanoparticles, methods of supporting NiPt nanoparticles, methods of using NiPt nanoparticles, and the like.

  18. A facile and practical biosensor for choline based on manganese dioxide nanoparticles synthesized in-situ at the surface of electrode by one-step electrodeposition.

    Science.gov (United States)

    Yu, Guangxia; Zhao, Qiang; Wu, Weixiang; Wei, Xiaoyun; Lu, Qing

    2016-01-01

    In this paper, a facile and sensitive biocompatible biosensor based on Nafion/choline oxidase/manganese dioxide composite film was developed for the determination of choline chloride. Manganese dioxide (MnO2) nanoparticles, possessing the advantages of large specific surface areas, good hydrophilicity, great permeability as well as excellent biocompatibility, were synthesized in-situ at the surface of the glassy carbon electrode (GCE) by one-step electrodeposition. And then, choline oxidase (ChOx) was immobilized on the MnO2 modified GCE with coating a Nafion film to hold the ChOx/MnO2 film on the electrode surface firmly. Upon optimized conditions, a linear range of 8.0-1.0 mM was obtained for the sensor in a cyclic voltammetry method, with a detection limit as low as 5.0 µM. Besides, the biosensor was successfully employed to detect choline in milk, milk powder and feedstuff samples, providing a promising alternative for the practical application. PMID:26695320

  19. One-step sonochemical syntheses of Ni@Pt core-shell nanoparticles with controlled shape and shell thickness for fuel cell electrocatalyst.

    Science.gov (United States)

    Lee, Eunjik; Jang, Ji-Hoon; Matin, Md Abdul; Kwon, Young-Uk

    2014-01-01

    We demonstrate a facile one-step method to synthesize Ni@Pt core-shell nanoparticles (NPs) with a control over the shape and the Pt-shell thickness of the NPs. By adjusting the relative reactivity of the Pt and Ni reagents in ultrasound-assisted polyol reactions, two Ni@Pt NP samples of the same composition (Ni/Pt=1) and size (3-4 nm) but with different particle shape (octahedral vs. truncated octahedral) and different Pt-shell thicknesses (1-2 vs. 2-3 monolayer) are obtained. The control is achieved by using different Ni reagents, Ni(acac)2 (acac=acetylacetonate) and Ni(hfac)2 (hfac=hexafluoroacetylacetonate). A reaction mechanism that can explain all of the observations is proposed. The Ni@Pt NPs show up to threefold higher mass activity than pure Pt NPs in oxygen reduction reaction. Between the two Ni@Pt NP samples, the one composed of octahedral NPs with the thicker Pt-shell has higher activity than the other. PMID:23769750

  20. Capacitive behaviour of MnF2 and CoF2 submicro/nanoparticles synthesized via a mild ionic liquid-assisted route

    Science.gov (United States)

    Ma, Ruguang; Zhou, Yao; Yao, Lin; Liu, Guanghui; Zhou, Zhenzhen; Lee, Jong-Min; Wang, Jiacheng; Liu, Qian

    2016-01-01

    Submicro-/nano-sized MnF2 rods and hierarchical CoF2 cuboids are respectively synthesized via a facile precipitation method assisted by ionic liquid under a mild condition. The as-prepared MF2 (M = Mn, Co) submicro/nanoparticles exhibit impressive specific capacitance in 1.0 M KOH aqueous solution, especially at relatively high current densities, e.g. 91.2, 68.7 and 56.4 F g-1 for MnF2, and 81.7, 70.6 and 63.0 F g-1 for CoF2 at 5, 8 and 10 A g-1, respectively. The mechanism of striking capacitance of MF2 is clarified on the basis of analysing the cycled electrodes by different characterization techniques. Such remarkable capacitance is ascribed to the redox reactions between MF2 and MOOH in aqueous alkaline electrolytes, which can not be obtained in aqueous neutral electrolytes. This study for the first time provides direct evidences on the pseudocapacitance mechanism of MF2 in alkaline electrolytes and paves the way of application of transition metal fluorides as electrodes in supercapacitors.

  1. Radiation synthesized poly(n-vinyl-2-pyrrolidone)-stabilized-gold nanoparticles as LSPR-based optical sensor for mercury ions estimation

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Nilanjal; Kumar, Virendra, E-mail: vkrawat75@gmail.com, E-mail: vkumar@barc.gov.in; Goel, Narender Kumar; Varshney, Lalit [Bhabha Atomic Research Centre, Radiation Technology Development Division (India)

    2015-07-15

    Poly(n-vinyl-2-pyrrolidone)-stabilized-gold nanoparticles (PVP-Au-NPs) have been synthesized via a green-{sup 60}Co-Gamma radiolytic route and employed as a localized surface plasmon resonance (LSPR)-based optical sensor for estimation of trace quantities of Hg{sup 2+} ion in aqueous solutions. The in situ generated PVP-Au-NPs were characterized using UV–vis spectroscopy, transmission electron microscopy, and particle size analysis techniques. Reaction conditions were optimized to obtain uniformly dispersed PVP-Au-NPs with average particle size of 7.1 ± 1.6 nm (±s), which exhibited a narrow LSPR band at ∼527 nm. The decrease in LSPR band intensity of PVP-Au-NPs with increase in Hg{sup 2+} ion concentration was found to be linear in the Hg{sup 2+} ion concentration range of 0–100 nM. The LSPR-based PVP-Au-NPs optical sensor system was found to be selective for Hg{sup 2+} and independent of interference from other metal ions such as Ca{sup 2+,} Cu{sup 2+}, Cd{sup 2+}, and Fe{sup 2+} up to a concentration of 500 nM.

  2. The mechanism for degrading Orange II based on adsorption and reduction by ion-based nanoparticles synthesized by grape leaf extract

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Fang; Yang, Die [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia); Chen, Zuliang, E-mail: zuliang.chen@unisa.edu.au [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia); Megharaj, Mallavarapu; Naidu, Ravendra [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2015-10-15

    Biomolecules taken from plant extracts have often been used in the single-step synthesis of iron-based nanoparticles (Fe NPs) due to their low cost, environmental safety and sustainable properties. However, the composition of Fe NPs and the degradation mechanism of organic contaminants by them are limited because these are linked to the reactivity of Fe NPs. In this study, Fe NPs synthesized by grape leaf extract served to remove Orange II. Batch experiments showed that more than 92% of Orange II was removed by Fe NPs at high temperature based on adsorption and reduction and confirmed by kinetic studies. To understand the role of Fe NPs in the removal process of azo dye, surface analysis via X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were employed, showing that the Fe NPs were composed of biomolecules, hydrous iron oxides and Fe{sup 0}, thus providing evidence for the adsorption of Orange II onto hydrous iron oxides and its reduction by Fe{sup 0}. Degraded products such as 2-naphthol were identified using LC–MS analysis. A degradation mechanism based on asymmetrical azo bond cleavage for the removal of Orange II was proposed.

  3. Facile approach to synthesize uniform Au@mesoporous SnO{sub 2} yolk–shell nanoparticles and their excellent catalytic activity in 4-nitrophenol reduction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ya [Changchun University of Science and Technology, School of Chemistry & Environmental Engineering (China); Li, Lu; Wang, Chungang, E-mail: wangcg925@nenu.edu.cn [Northeast Normal University, Faculty of Chemistry (China); Wang, Tingting, E-mail: wangtt@cust.edu.cn [Changchun University of Science and Technology, School of Chemistry & Environmental Engineering (China)

    2016-01-15

    Monodispersed and uniform Au@mesoporous SnO{sub 2} yolk–shell nanoparticles (Au@mSnO{sub 2} yolk–shell NPs) composed of the moveable Au NP cores and mSnO{sub 2} shells have been successfully fabricated via a facile and reproducible approach. The outside mSnO{sub 2} shells of Au@mSnO{sub 2} yolk–shell NPs not only prevent Au NPs from aggregating and corroding by the reaction solution but also allow the Au NPs to contact with reactant molecules easily through the mesoporous channels. The obtained Au@mSnO{sub 2} yolk–shell NPs are characterized by means of transmission electron microscope, scanning electron microscopy, X-ray powder diffraction, X-ray photoelectron spectrum, and UV–vis absorption spectroscopy. The synthesized materials exhibit excellent catalytic performance and high stability towards the reduction of 4-nitrophenol with NaBH{sub 4} as a reducing agent, which may be ascribed to their high specific surface area and unique mesoporous structure. Moreover, the synthetic strategy reported in this paper can be extended to fabricate a series of multifunctional noble metal@metal oxide yolk–shell nanocomposite materials with unique properties for various applications.

  4. Biologically synthesized silver nanoparticles induce neuronal differentiation of SH-SY5Y cells via modulation of reactive oxygen species, phosphatases, and kinase signaling pathways.

    Science.gov (United States)

    Dayem, Ahmed Abdal; Kim, BongWoo; Gurunathan, Sangiliyandi; Choi, Hye Yeon; Yang, Gwangmo; Saha, Subbroto Kumar; Han, Dawoon; Han, Jihae; Kim, Kyeongseok; Kim, Jin-Hoi; Cho, Ssang-Goo

    2014-07-01

    Nano-scale materials are noted for unique properties, distinct from those of their bulk material equivalents. In this study, we prepared spherical silver nanoparticles (AgNPs) with an average size of about 30 nm and tested their potency to induce neuronal differentiation of SH-SY5Y cells. Human neuroblastoma SH-SY5Y cells are considered an ideal in vitro model for studying neurogenesis, as they can be maintained in an undifferentiated state or be induced to differentiate into neuron-like phenotypes in vitro by several differentiation-inducing agents. Treatment of SH-SY5Y cells by biologically synthesized AgNPs led to cell morphological changes and significant increase in neurite length and enhanced the expression of neuronal differentiation markers such as Map-2, β-tubulin III, synaptophysin, neurogenin-1, Gap-43, and Drd-2. Furthermore, we observed an increase in generation of intracellular reactive oxygen species (ROS), activation of several kinases such as ERK and AKT, and downregulation of expression of dual-specificity phosphatases (DUSPs) in AgNPs-exposed SH-SY5Y cells. Our results suggest that AgNPs modulate the intracellular signaling pathways, leading to neuronal differentiation, and could be applied as promising nanomaterials for stem cell research and therapy. PMID:24827677

  5. Biologically synthesized silver nanoparticles induce neuronal differentiation of SH-SY5Y cells via modulation of reactive oxygen species, phosphatases, and kinase signaling pathwayss.

    Science.gov (United States)

    Dayem, Ahmed Abdal; Kim, Bongwoo; Gurunathan, Sangiliyandi; Choi, Hye Yeon; Yang, Gwangmo; Saha, Subbroto Kumar; Han, Dawoon; Han, Jihae; Kim, Kyeongseok; Kim, Jin-Hoi; Cho, Ssang-Goo

    2014-04-22

    The relevant in vitro cellular model resembling functional neurons is important for the mechanistic research on various neuronal diseases. Human neuroblastoma SH-SY5Y cells may be considered one of the ideal in vitro models for studying neuroscience, as they can be maintained in an undifferentiated state or be induced to differentiate into neuron-like phenotypes in vitro by several differentiation-inducing agents. In this study, we prepared spherical silver nanoparticles (AgNPs) with an average size of about 30 nm and tested their potency to induce neuronal differentiation of SH-SY5Y cells. Treatment of SH-SY5Y cells by biologically synthesized AgNPs led to cell morphological changes and significant increase in neurite length and enhanced the expression of neuronal differentiation markers such as Map-2, β-tubulin III, synaptophysin, neurogenin-1, Gap-43, and Drd-2. Furthermore, we observed an increase in generation of intracellular reactive oxygen species (ROS), activation of several kinases such as ERK and AKT, and down-regulation of expression of dual-specificity phosphatases (DUSPs) in AgNPs-exposed SH-SY5Y cells. Our results suggest that AgNPs could modulate the intracellular signaling pathways to lead to neuronal differentiation, and could be applied as promising nanomaterials for stem cell research and therapy. PMID:24753441

  6. Atomic-scale microstructural characterization and dielectric properties of crystalline cubic pyrochlore Bi1.5MgNb1.5O7 nanoparticles synthesized by sol-gel method

    KAUST Repository

    Zhang, Yuan

    2013-12-24

    Here, we report the atomic-scale microstructural characterization and dielectric properties of crystalline cubic pyrochlore Bi1.5MgNb 1.5O7 (BMN) nanoparticles with mean size of 70 nm, which were synthesized by sol-gel method. The crystallinity, phase formation, morphology, and surface microstructure of the BMN nanoparticles were characterized by X-ray diffraction (XRD), Raman spectra, transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM), respectively. The phase evolution of the BMN nanoparticles investigated by XRD patterns showed that uniform cubic pyrochlore BMN nanoparticles were obtained after calcination at temperature of 800 C, and their structural information was revealed by Raman spectrum. TEM images demonstrated that the BMN nanoparticles had a spherical morphology with an average particle size of 70 nm, and their crystalline nature was revealed by HRTEM images. In addition, HRTEM images also demonstrate a terrace-ledge-kink (TLK) surface structure at the edges of rough BMN nanoparticles, where the terrace was on the (100) plane, and the ledge on the (001) plane. The formation of such a TLK surface structure can be well explained by a theory of periodic bond chains. Due to the surface structural reconstruction in the BMN nanoparticles, the formation of a tetragonal structure in a rough BMN nanoparticle was also revealed by HRTEM image. The BMN nanoparticles exhibited dielectric constants of 50 at 100 kHz and 30 at 1 MHz, and the dielectric loss of 0.19 at 1 MHz. © 2013 Springer Science+Business Media Dordrecht.

  7. Structural, optical, electrical, and magnetic properties of Zn0.7MnxNi0.3−xO nanoparticles synthesized by sol–gel technique

    Directory of Open Access Journals (Sweden)

    Sarita Sharma

    2015-12-01

    Full Text Available The structural, morphology, optical, electrical, and magnetic properties of Zn0.7MnxNi0.3−xO (x = 0.05, 0.1, 0.15, 0.2 nanoparticles synthesized by sol–gel technique have been systematically investigated by using X-ray diffractometer (XRD, scanning electron microscope (SEM, UV–vis-NIR spectrophotometer, impedance analyzer, and vibration sample magnetometer (VSM. XRD patterns reveal that all samples have hexagonal wurtzite structure along with secondary phases such as NiO and ZnMnO3. The average crystalline size increases with the increase in the Mn concentration in the host matrix. Diffuse reflectance studies (DRS show an increment in optical band gap with increasing Mn content. AC conductivity of present samples has been studied as a function of frequency (100 Hz–10 MHz of the applied AC signal in the temperature range of 323–463 K. The results showed that AC conductivity increases with an increase in frequency and temperature. The frequency exponent shows that small polaron conduction mechanism is the most favorable for all samples. The value of AC conductivity is observed to decrease with an increase in the Mn dopant concentration in the Zn0.7MnxNi0.3−xO system. At room temperature, magnetic characterization of the samples indicates the presence of both paramagnetic and ferromagnetic behavior. Magnetic saturation decreases with the increase in the Mn concentration in the host lattice.

  8. Synthesize Triangular Silver Nanoparticle by Photo-induced Reaction%光诱导合成三角板银纳米粒子的研究

    Institute of Scientific and Technical Information of China (English)

    杜虹; 赵淑贤; 董磊

    2011-01-01

    采用钠灯作为光诱导反应的光源,利用柠檬酸钠为稳定剂和结构导向剂,以硼氢化钠为还原剂,在水相中光诱导合成三角板银纳米粒子.考察了柠檬酸钠、硼氢化钠比例对粒子形貌的影响,确定最佳比例为[AgNO3]:[Na3C6H5O7]:[NaBH4]=1:25:0.4(物质的量比).采用透射电镜(TEM)、紫外可见吸收光谱(UV-Vis)、X-射线粉末衍射仪(XRD)对实验样品的形貌、光学性质及晶体结构进行表征.%Triangular silver naoplates were synthesized by irradiating the growth solution, which contained silver cations and citrate anions. The sodium lamp was chosen as the light source. The citrate anions in the system acted as stabilizers,and sodium borohydride acted as reducing agents. The spectral evolution of the growth process was monitored by the UV-vis spectrometer,and the corresponding shape,size and crystallo-graphic structure of nanoparticles in details were investigated by transmission electron microscope(TEM) and X-ray diffraction (XRD). We also estimated the influences of the molar ration between citrate anions and sodium borohydride on the final products.

  9. Effects of pH and citric acid content on the structure and magnetic properties of MnZn ferrite nanoparticles synthesized by a sol–gel autocombustion method

    International Nuclear Information System (INIS)

    MnZn ferrite nanoparticles have been synthesized by a sol–gel autocombustion technique with different pHs of 0, 5 and 7 and different citric acid to metal nitrate (CA/MN) molar ratios of 0.25, 0.5 and 1. The crystallite size, microstructure and magnetic properties were studied using X-ray diffraction, scanning electron microscopy and vibrating sample magnetometry methods. The results showed that the single phase MnZn ferrite could be achieved directly without any post-calcination using pH of 7 and CA/MN molar ratio of 0.5. MnZn ferrite nanoparticles prepared by pH=7 and CA/MN=0.5 with the crystallite size of 39 nm exhibited saturation magnetization of 20.9 emu/g and coercivity of 44 Oe. - Highlights: • MnZnFe2O4 nanoparticles were synthesized by the sol–gel autocombustion technique at different pHs and citric acid to metal nitrate (CA/MN) molar ratios. • The single phase MnZn ferrite was achieved directly without any post-calcination using pH=7 and CA/MN molar ratio=0.5. • Single phase nanoparticles exhibited partially inverse spinel structures. • Magnetization was correlated to the inversion factor and crystallite size

  10. A novel hydrothermal approach for synthesizing α-Fe{sub 2}O{sub 3}, γ-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} mesoporous magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jayanthi, S. Amala [Department of Physics, Government Arts College (Autonomous), Nandanam, Chennai, 600 035 (India); Nathan, D. Muthu Gnana Theresa; Jayashainy, J. [Department of Physics, Loyola College (Autonomous), Chennai, 600 034 (India); Sagayaraj, P., E-mail: psagayaraj@hotmail.com [Department of Physics, Loyola College (Autonomous), Chennai, 600 034 (India)

    2015-07-15

    A novel method to synthesize the three phases of iron oxide nanoparticles (hematite, maghemite and magnetite) using the same non-toxic inorganic precursors via a water–organic interface under the low temperature hydrothermal conditions is reported. The synthesized particles are characterized by Powder X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). The Brunauer–Emmett–Teller (BET) results reveal the mesoporous nature of the particles. The magnetic properties of the nanoparticles are studied by Vibrating Sample Magnetometer (VSM) at various low temperatures and also at room temperature. The XRD peaks corresponding to each sample clearly depict the presence of the respective phase of the as-prepared magnetic nanoparticles. The nanoparticles of maghemite and magnetite have saturation magnetization of 58.56 and 40.30 emu/g respectively at room temperature, whereas the particles of hematite possess very low saturation magnetization value of 1.89 emu/g. Further, the magnetization is studied at four different temperatures and the zero field cooled (ZFC) and field cooled (FC) magnetization are reported. - Graphical abstract: Display Omitted - Highlights: • Hematite, maghemite and magnetite are obtained under hydrothermal synthesis. • α-Fe{sub 2}O{sub 3}, γ-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} prepared are mesoporous and nearly monodisperse. • Near superparamagnetism is observed at room temperature for maghemite and magnetite.

  11. Evaluation of Antioxidant and Cytotoxicity Activities of Copper Ferrite (CuFe2O4 and Zinc Ferrite (ZnFe2O4 Nanoparticles Synthesized by Sol-Gel Self-Combustion Method

    Directory of Open Access Journals (Sweden)

    Samikannu Kanagesan

    2016-08-01

    Full Text Available Spinel copper ferrite (CuFe2O4 and zinc ferrite (ZnFe2O4 nanoparticles were synthesized using a sol-gel self-combustion technique. The structural, functional, morphological and magnetic properties of the samples were investigated by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, Transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. XRD patterns conform to the copper ferrite and zinc ferrite formation, and the average particle sizes were calculated by using a transmission electron microscope, the measured particle sizes being 56 nm for CuFe2O4 and 68 nm for ZnFe2O4. Both spinel ferrite nanoparticles exhibit ferromagnetic behavior with saturation magnetization of 31 emug−1 for copper ferrite (50.63 Am2/Kg and 28.8 Am2/Kg for zinc ferrite. Both synthesized ferrite nanoparticles were equally effective in scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH free radicals. ZnFe2O4 and CuFe2O4 nanoparticles showed 30.57% ± 1.0% and 28.69% ± 1.14% scavenging activity at 125 µg/mL concentrations. In vitro cytotoxicity study revealed higher concentrations (>125 µg/mL of ZnFe2O4 and CuFe2O4 with increased toxicity against MCF-7 cells, but were found to be non-toxic at lower concentrations suggesting their biocompatibility.

  12. Structural and magnetic properties of Co0.7Ni0.3Fe2O4 nanoparticles synthesized by sol-gel method

    Science.gov (United States)

    Mahhouti, Z.; Ben Ali, M.; El Moussaoui, H.; Hamedoun, M.; El Marssi, M.; El Kenz, A.; Benyoussef, A.

    2016-07-01

    In this paper, we present the structural and magnetic properties of Co0.7Ni0.3Fe2O4 nanoparticles. The nanoparticles are prepared by the sol-gel method; structural analysis by X-ray diffraction shows that the nanoparticles are pure phase with the spinel structure. Transmission electron microscopy analysis reveals the local microstructure of the particles and their size range of 6-8 nm, with isometric shape. The magnetic properties obtained with magnetic properties measurement system demonstrate the soft magnetic character of the nanoparticles.

  13. Effect of Gd doping on the structural, luminescence and magnetic properties of ZnS nanoparticles synthesized by the hydrothermal method

    Science.gov (United States)

    Poornaprakash, B.; Chalapathi, U.; Reddeppa, Maddaka; Park, Si-Hyun

    2016-09-01

    This paper reports the synthesis and characterization of ZnS:Gd nanoparticles prepared by a hydrothermal process using different doping concentrations. The chemical, structural, luminescence and magnetic properties of these nanoparticles were investigated by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, and vibrating sample magnetometer (VSM) measurements. XRD confirmed that all the samples had a cubic structure with good crystallinity. HRTEM showed that the particles were polycrystalline with a mean size of 4-6 nm. XPS revealed the oxidation state of Gd in the ZnS lattice to be +3. The PL spectra of all the nanoparticles exhibited broad emission peaks in the visible region. All the Gd doped nanoparticles exhibited well-defined ferromagnetic behavior at room temperature. The saturation magnetization increased significantly with increasing Gd concentration, reaching a maximum for 3 at.% Gd and decreasing for the 5 at.% Gd doped ZnS nanoparticles.

  14. Fern-synthesized nanoparticles in the fight against malaria: LC/MS analysis of Pteridium aquilinum leaf extract and biosynthesis of silver nanoparticles with high mosquitocidal and antiplasmodial activity.

    Science.gov (United States)

    Panneerselvam, Chellasamy; Murugan, Kadarkarai; Roni, Mathath; Aziz, Al Thabiani; Suresh, Udaiyan; Rajaganesh, Rajapandian; Madhiyazhagan, Pari; Subramaniam, Jayapal; Dinesh, Devakumar; Nicoletti, Marcello; Higuchi, Akon; Alarfaj, Abdullah A; Munusamy, Murugan A; Kumar, Suresh; Desneux, Nicolas; Benelli, Giovanni

    2016-03-01

    Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum strains resistant to chloroquine. There is an urgent need to investigate new and effective sources of antimalarial drugs. This research proposed a novel method of fern-mediated synthesis of silver nanoparticles (AgNP) using a cheap plant extract of Pteridium aquilinum, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Phytochemical analysis of P. aquilinum leaf extract revealed the presence of phenols, alkaloids, tannins, flavonoids, proteins, carbohydrates, saponins, glycosides, steroids, and triterpenoids. LC/MS analysis identified at least 19 compounds, namely pterosin, hydroquinone, hydroxy-acetophenone, hydroxy-cinnamic acid, 5, 7-dihydroxy-4-methyl coumarin, trans-cinnamic acid, apiole, quercetin 3-glucoside, hydroxy-L-proline, hypaphorine, khellol glucoside, umbelliferose, violaxanthin, ergotamine tartrate, palmatine chloride, deacylgymnemic acid, methyl laurate, and palmitoyl acetate. In DPPH scavenging assays, the IC50 value of the P. aquilinum leaf extract was 10.04 μg/ml, while IC50 of BHT and rutin were 7.93 and 6.35 μg/ml. In mosquitocidal assays, LC50 of P. aquilinum leaf extract against Anopheles stephensi larvae and pupae were 220.44 ppm (larva I), 254.12 ppm (II), 302.32 ppm (III), 395.12 ppm (IV), and 502.20 ppm (pupa). LC50 of P. aquilinum-synthesized AgNP were 7.48 ppm (I), 10.68 ppm (II), 13.77 ppm (III), 18.45 ppm (IV), and 31.51 ppm (pupa). In the field, the application of P. aquilinum extract and AgNP (10 × LC50) led to 100 % larval reduction after 72 h. Both the P. aquilinum extract and AgNP reduced longevity and fecundity of An. stephensi adults. Smoke toxicity experiments conducted against An. stephensi adults showed that P. aquilinum leaf-, stem-, and root-based coils

  15. Fern-synthesized nanoparticles in the fight against malaria: LC/MS analysis of Pteridium aquilinum leaf extract and biosynthesis of silver nanoparticles with high mosquitocidal and antiplasmodial activity.

    Science.gov (United States)

    Panneerselvam, Chellasamy; Murugan, Kadarkarai; Roni, Mathath; Aziz, Al Thabiani; Suresh, Udaiyan; Rajaganesh, Rajapandian; Madhiyazhagan, Pari; Subramaniam, Jayapal; Dinesh, Devakumar; Nicoletti, Marcello; Higuchi, Akon; Alarfaj, Abdullah A; Munusamy, Murugan A; Kumar, Suresh; Desneux, Nicolas; Benelli, Giovanni

    2016-03-01

    Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum strains resistant to chloroquine. There is an urgent need to investigate new and effective sources of antimalarial drugs. This research proposed a novel method of fern-mediated synthesis of silver nanoparticles (AgNP) using a cheap plant extract of Pteridium aquilinum, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Phytochemical analysis of P. aquilinum leaf extract revealed the presence of phenols, alkaloids, tannins, flavonoids, proteins, carbohydrates, saponins, glycosides, steroids, and triterpenoids. LC/MS analysis identified at least 19 compounds, namely pterosin, hydroquinone, hydroxy-acetophenone, hydroxy-cinnamic acid, 5, 7-dihydroxy-4-methyl coumarin, trans-cinnamic acid, apiole, quercetin 3-glucoside, hydroxy-L-proline, hypaphorine, khellol glucoside, umbelliferose, violaxanthin, ergotamine tartrate, palmatine chloride, deacylgymnemic acid, methyl laurate, and palmitoyl acetate. In DPPH scavenging assays, the IC50 value of the P. aquilinum leaf extract was 10.04 μg/ml, while IC50 of BHT and rutin were 7.93 and 6.35 μg/ml. In mosquitocidal assays, LC50 of P. aquilinum leaf extract against Anopheles stephensi larvae and pupae were 220.44 ppm (larva I), 254.12 ppm (II), 302.32 ppm (III), 395.12 ppm (IV), and 502.20 ppm (pupa). LC50 of P. aquilinum-synthesized AgNP were 7.48 ppm (I), 10.68 ppm (II), 13.77 ppm (III), 18.45 ppm (IV), and 31.51 ppm (pupa). In the field, the application of P. aquilinum extract and AgNP (10 × LC50) led to 100 % larval reduction after 72 h. Both the P. aquilinum extract and AgNP reduced longevity and fecundity of An. stephensi adults. Smoke toxicity experiments conducted against An. stephensi adults showed that P. aquilinum leaf-, stem-, and root-based coils

  16. Soft template strategy to synthesize iron oxide-titania yolk-shell nanoparticles as high-performance anode materials for lithium-ion battery applications.

    Science.gov (United States)

    Lim, Joohyun; Um, Ji Hyun; Ahn, Jihoon; Yu, Seung-Ho; Sung, Yung-Eun; Lee, Jin-Kyu

    2015-05-18

    Yolk-shell-structured nanoparticles with iron oxide core, void, and a titania shell configuration are prepared by a simple soft template method and used as the anode material for lithium ion batteries. The iron oxide-titania yolk-shell nanoparticles (IO@void@TNPs) exhibit a higher and more stable capacity than simply mixed nanoparticles of iron oxide and hollow titania because of the unique structure obtained by the perfect separation between iron oxide nanoparticles, in combination with the adequate internal void space provided by stable titania shells. Moreover, the structural effect of IO@void@TNPs clearly demonstrates that the capacity retention value after 50 cycles is approximately 4 times that for IONPs under harsh operating conditions, that is, when the temperature is increased to 80 °C.

  17. Influence of dopant concentrations (Mn = 1, 2 and 3 mol%) on the structural, magnetic and optical properties and photocatalytic activities of SnO2 nanoparticles synthesized via the simple precipitation process

    Science.gov (United States)

    Anandan, K.; Rajendran, V.

    2015-09-01

    We have successfully synthesized pure and Mn (1-3 mol%)-doped SnO2 nanoparticles via the facile precipitation method. The influence of Mn concentrations on SnO2 nanoparticles properties were systematically investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, vibrating sample magnetometer (VSM), ultraviolet visible (UV-Vis) spectroscopy and photoluminescence (PL) spectroscopy. On the other hand, the photocatalytic degradation of the Methyl orange dye was comparatively investigated, by using pure and 1-3% concentration of Mn-doped SnO2 samples and the mechanism has been discussed. All the results demonstrate that doping levels have strong influences on the structural, magnetic, and optical properties and photocatalytic activity performances.

  18. A spectroscopic study on interaction between bovine serum albumin and titanium dioxide nanoparticle synthesized from microwave-assisted hybrid chemical approach.

    Science.gov (United States)

    Ranjan, Shivendu; Dasgupta, Nandita; Srivastava, Priyanka; Ramalingam, Chidambaram

    2016-08-01

    The use of nanoparticles in food or pharma requires a molecular-level perceptive of how NPs interact with protein corona once exposed to a physiological environment. In this study, the conformational changes of bovine serum albumin (BSA) were investigated in detail when exposed to different concentration of titanium dioxide nanoparticle by various techniques. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin and titanium dioxide nanoparticles at different concentrations were investigated. The interaction, BSA conformations, kinetics, and adsorption were analyzed by dynamic light scattering, Fourier transform infrared spectroscopy and fluorescence quenching. Dynamic light scattering analysis confirms the interaction with major changes in the size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.1 molecules of serum albumin to titanium dioxide nanoparticles. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The spectroscopic analysis suggests that there is a conformational change both at secondary and tertiary structure levels. A distortion in both α-helix and β-sheets was observed by Fourier transform infrared (FTIR) spectroscopy. Fluorescence quenching analysis confirms the interaction of a molecule of bovine serum albumin to the single TiO2 nanoparticle. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The data of the present study determines the detailed evaluation of BSA adsorption on TiO2 nanoparticle along with mechanism and adsorption kinetics.

  19. A spectroscopic study on interaction between bovine serum albumin and titanium dioxide nanoparticle synthesized from microwave-assisted hybrid chemical approach.

    Science.gov (United States)

    Ranjan, Shivendu; Dasgupta, Nandita; Srivastava, Priyanka; Ramalingam, Chidambaram

    2016-08-01

    The use of nanoparticles in food or pharma requires a molecular-level perceptive of how NPs interact with protein corona once exposed to a physiological environment. In this study, the conformational changes of bovine serum albumin (BSA) were investigated in detail when exposed to different concentration of titanium dioxide nanoparticle by various techniques. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin and titanium dioxide nanoparticles at different concentrations were investigated. The interaction, BSA conformations, kinetics, and adsorption were analyzed by dynamic light scattering, Fourier transform infrared spectroscopy and fluorescence quenching. Dynamic light scattering analysis confirms the interaction with major changes in the size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.1 molecules of serum albumin to titanium dioxide nanoparticles. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The spectroscopic analysis suggests that there is a conformational change both at secondary and tertiary structure levels. A distortion in both α-helix and β-sheets was observed by Fourier transform infrared (FTIR) spectroscopy. Fluorescence quenching analysis confirms the interaction of a molecule of bovine serum albumin to the single TiO2 nanoparticle. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The data of the present study determines the detailed evaluation of BSA adsorption on TiO2 nanoparticle along with mechanism and adsorption kinetics. PMID:27318604

  20. Multipurpose effectiveness of Couroupita guianensis-synthesized gold nanoparticles: high antiplasmodial potential, field efficacy against malaria vectors and synergy with Aplocheilus lineatus predators.

    Science.gov (United States)

    Subramaniam, Jayapal; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Kovendan, Kalimuthu; Madhiyazhagan, Pari; Dinesh, Devakumar; Kumar, Palanisamy Mahesh; Chandramohan, Balamurugan; Suresh, Udaiyan; Rajaganesh, Rajapandian; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Canale, Angelo; Benelli, Giovanni

    2016-04-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. According to recent estimates, about 3.2 billion people, almost half of the world's population, are at risk of malaria. Malaria control is particularly challenging due to a growing number of chloroquine-resistant Plasmodium and pesticide-resistant Anopheles vectors. Newer and safer control tools are required. In this research, gold nanoparticles (AuNPs) were biosynthesized using a cheap flower extract of Couroupita guianensis as reducing and stabilizing agent. The biofabrication of AuNP was confirmed by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), zeta potential, and particle size analysis. AuNP showed different shapes including spheres, ovals, and triangles. AuNPs were crystalline in nature with face-centered cubic geometry; mean size was 29.2-43.8 nm. In laboratory conditions, AuNPs were toxic against Anopheles stephensi larvae, pupae, and adults. LC50 was 17.36 ppm (larva I), 19.79 ppm (larva II), 21.69 ppm (larva III), 24.57 ppm (larva IV), 28.78 ppm (pupa), and 11.23 ppm (adult). In the field, a single treatment with C. guianensis flower extract and AuNP (10 × LC50) led to complete larval mortality after 72 h. In standard laboratory conditions, the predation efficiency of golden wonder killifish, Aplocheilus lineatus, against A. stephensi IV instar larvae was 56.38 %, while in an aquatic environment treated with sub-lethal doses of the flower extract or AuNP, predation efficiency was boosted to 83.98 and 98.04 %, respectively. Lastly, the antiplasmodial activity of C. guianensis flower extract and AuNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. IC50 of C. guianensis flower extract was 43.21 μg/ml (CQ-s) and 51.16 μg/ml (CQ-r). AuNP IC50 was 69.47 μg/ml (CQ-s) and 76

  1. Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanoparticles dispersed in a SiO{sub 2} matrix synthesized by sol-gel processing

    Energy Technology Data Exchange (ETDEWEB)

    Pozo Lopez, G., E-mail: gpozo@famaf.unc.edu.ar [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000, Cordoba (Argentina); Instituto de Fisica Enrique Gaviola - CONICET (Argentina); Condo, A.M. [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Av. Bustillo 9500, 8400, San Carlos de Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo, Av. Bustillo 9500, 8400, San Carlos de Bariloche (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Urreta, S.E. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000, Cordoba (Argentina); Silvetti, S.P.; Aguirre, M. del C. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000, Cordoba (Argentina); Instituto de Fisica Enrique Gaviola - CONICET (Argentina)

    2012-12-15

    (Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4})x/(SiO{sub 2})(100 - x) (x = 5, 20 and 50 wt.%) nanocomposites are synthesized by a sol-gel method using tetraethylorthosilicate (TEOS) and metallic nitrates as precursors, and by further annealing the powders for 1 h at 1273 K. X-ray diffraction (XRD), transmission electron microscopy (TEM), room temperature vibrating sample magnetometry (VSM) and SQUID measurements are employed for structural, morphological and magnetic sample characterization. For all the concentrations analyzed, the powder nanocomposites actually consist of spinel NiZn ferrite nanoparticles, dispersed in an amorphous silica matrix. TEM studies reveal different particle size distributions and particle morphologies for the three ferrite contents. The 20 wt.%-NiZn ferrite samples consist of nearly spherical nanoparticles, of about 8 nm, mainly superparamagnetic, well-dispersed in the amorphous silica matrix, while the 5 wt.%-NiZn ferrite samples exhibit a bimodal particle size distribution (5 and 30 nm) of single-domain nanoparticles embedded in the silica. In the 50 wt.%-NiZn ferrite samples, two particle families are observed: small round superparamagnetic nanoparticles of about 8 nm embedded in the amorphous silica matrix and large, non-spherical, ferrimagnetic ones, forming agglomerates outside the matrix. In all the synthesized samples, thickness fringes are observed inside some of the ferrite nanoparticles in dark field images. This contrast is explained using the theory of electron diffraction in a weak beam dark field (WBDF) condition and considering spherical ferrite nanoparticles. A large range of tailored magnetic properties varying the fraction, dispersion and mean size of the ferrimagnetic NiZn ferrite particles is obtained. Room temperature saturation magnetization values are found in the range 3.0-30.4 Am{sup 2}/kg for the different concentration samples. Coercivity values, between 1.9 and 7.6 mT, are more than 50% higher than those measured

  2. Morphology and luminescence characteristics of combustion synthesized Y{sub 2}O{sub 3}: (Eu, Dy, Tb) nanoparticles with various amino-acid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S.; Sudarsan, V. [Chemistry Division Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sastry, P.U.; Patra, A.K. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Tyagi, A.K., E-mail: aktyagi@barc.gov.in [Chemistry Division Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2014-01-15

    Y{sub 2}O{sub 3} nanoparticles doped with Dy{sup 3+}, Eu{sup 3+} and Tb{sup 3+} together were prepared by the gel combustion method using a variety of amino acids namely, glycine, phenyl alanine, arginine, glutamic and aspartic acids. Number of carboxylate groups present in the amino acids used for combustion reaction was found to have strong influence on powder characteristics as well as luminescence from the samples. Based on small angle X-ray scattering studies, it is inferred that the nanoparticles prepared by using glycine and arginine as the fuels have smooth surface compared to those prepared using other amino acids. For the nanoparticles prepared using glutamic and aspartic acids, there exist a diffused pore-grain interface due to the lesser extent of heat generated in the reaction which leads to smaller particle size, poor crystallinity and improper burning of the organic materials. Lower surface area and smooth surface of the nanoparticles prepared using glycine leads to their improved luminescence properties. -- Highlights: • Surface smoothness of Y{sub 2}O{sub 3} (Dy, Eu, Tb) nanoparticles vary with amino acids. • Optimum luminescence intensity is observed when glycine is used as the fuel. • Diffused pore grain interface when glutamic and aspartic acids are used as fuels.

  3. Effects of annealing temperature variation on the evolution of structural and magnetic properties of NiFe2O4 nanoparticles synthesized by starch-assisted sol-gel auto-combustion method

    Science.gov (United States)

    Singh Yadav, Raghvendra; Havlica, Jaromir; Masilko, Jiri; Kalina, Lukas; Wasserbauer, Jaromir; Hajdúchová, Miroslava; Enev, Vojtěch; Kuřitka, Ivo; Kožáková, Zuzana

    2015-11-01

    Evolution of the structural and magnetic properties of NiFe2O4 nanoparticles synthesized by starch-assisted sol-gel auto-combustion method, and exposed to further annealing at 200 °C, 400 °C, 600 °C, 800 °C and 1000 °C, was evaluated in detail and correlation of these properties explored. The ferrite nanoparticles were characterized by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy and Vibrating Sample Magnetometer. The X-ray diffraction patterns demonstrated single phase formation of NiFe2O4 spinel ferrite nanoparticles at different annealing temperature 200 °C, 400 °C, 600 °C, 800 °C and 1000 °C. The change in crystallite size with increase of annealing temperature is observed. The FE-SEM analysis also indicated an increase of particle size with increase of higher annealing temperature. The change in Raman modes and infrared absorption bands were noticed with change of particle size. The X-ray photoelectron spectroscopy revealed the presence of Ni2+ and Fe3+ at octahedral and tetrahedral sites in NiFe2O4 nanoparticles. The representative sample NiFe2O4 nanoparticles annealed at 400 °C, have mixed cation distribution (Ni0.23+2 Fe0.52+3)[ Ni0.77+2 Fe1.48+3 ]O4. The highest value of coercivity 62.35 Oe and saturation magnetization 34.10 erg/g were obtained at annealing temperature 600 °C and 1000 °C, respectively.

  4. Sm-Doped Tio2 Nanoparticles with High Photocatalytic Activity for ARS Dye Under Visible Light Synthesized by Ultrasonic Assisted Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    V. Aware Dinkar

    2016-05-01

    Full Text Available In this article series of nano crystalline Sm-doped TiO2 nano particles with various molar concentration of samarium were synthesized by modified ultrasonic assisted sol-gel method and calcined at 500°C for 2 h. The synthesized nanomaterials were characterized in details using XRD, TEM, XPS UV–vis DRS and BET analysis. The detailed photocatalytic activity results revealed that doped samples shows excellent photodegradation efficiency towards model pollutant Alizarin red-S (ARS and almost 93% dye degrades within 120 minutes. The highest photodegradation efficiency was noticed for 1mole % samarium doped sample at 50 mgL-1 of catalyst dose. The photocatalytic activity of synthesized nano particles were also compared with commercially available ZnO and TiO2 (Degussa, P-25 photocatalyst. It was found that synthesized nano materials showed enhanced photocatalytic efficiency than commercially available semiconducting photocatalyst.

  5. Enhancement of photocatalytic activity of combustion-synthesized CeO{sub 2}/C{sub 3}N{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dong-Feng; Yang, Ke; Wang, Xiao-qin; Ma, Ya-Li; Huang, Gui-Fang; Huang, Wei-Qing [Hunan University, Department of Applied Physics, School of Physics and Electronics, Changsha (China)

    2015-09-15

    Nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} was synthesized via a one-step solution combustion method using urea as fuel for the first time. The effects of the molar ratio of urea to cerium chloride on the photocatalytic activity of the synthesized samples were investigated. The synthesized nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} shows small size and large surface exposure area. Photocatalytic degradation of methylene blue demonstrates that the synthesized nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} possesses enhanced photocatalytic activity. It is proposed that the enhanced photocatalytic activity might be related to the favorable morphology and structure, and the effective charge separation between C{sub 3}N{sub 4} and CeO{sub 2} in the photocatalytic process. (orig.)

  6. Structural and magnetic studies of the nickel doped CoFe2O4 ferrite nanoparticles synthesized by the chemical co-precipitation method

    International Nuclear Information System (INIS)

    The physical properties of nickel doped cobalt ferrite nanoparticles NixCo1−xFe2O4 (x=0.5, 0.75, 0.9) derived by the chemical co-precipitation route are characterized by XRD, FTIR, TEM, EPR, search coil and ac susceptibility techniques to develop stable kerosene based ferrofluid. XRD patterns and TEM images confirm the single phase formation of NixCo1-xFe2O4 nanoparticles whose crystallite size increases and lattice parameters decreases with the increase in Ni content. EPR resonance signal peak-to-peak line width and resonance field value decreases with the increase in Ni concentration in these samples. The broad nature of resonance signal is attributed to the ferromagnetic nature of the as-prepared nanoparticles and the increase in super exchange interaction among Ni2+-O-Co2+ facilitate the shifting of resonance value to lower field. The hysteresis loops of these nickel doped cobalt ferrite analogs exhibits highly magnetic nature of these nanoparticles at ambient temperature whose saturation magnetization, coerecivity and remanence magnetization decreases linearly with the increase in Ni-concentration in cobalt ferrite. The magnetic susceptibility with temperature curve shows increasing trend of blocking temperature with rise in nickel ion concentration. - Graphical abstract: Magnetic Characteristics variation in Nickel Doped cobalt ferrite nanoparticles with nickel content through structural and morphological correlation. - Highlights: • Nickel doped Cobalt ferrite nanoparticles (NPs) synthesis by the co-precipitation route. • Explored magnetic properties variation with nickel content. • Lattice parameter decreases and crystallite size increases with Ni2+ content. • NPs Ferromagnetic nature is confirmed by EPR and search coil studies. • Magnetocrystalline anisotropy of Ni2+ ions increases blocking temperature

  7. Structural and magnetic studies of the nickel doped CoFe{sub 2}O{sub 4} ferrite nanoparticles synthesized by the chemical co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ashok, E-mail: ashok.physics22@gmail.com [Department of Physics, Deenbandhu Chhotu Ram University of Science & Technology, Murthal, 131039 Haryana (India); Yadav, Nisha; Rana, Dinesh S. [Department of Instrumentation, Kurukshetra University, Kurukshetra, 136119 Haryana (India); Kumar, Parmod [Materials Science Division, Inter University Accelerator Center, 110067 New Delhi (India); Arora, Manju; Pant, R.P. [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, 110012 New Delhi (India)

    2015-11-15

    The physical properties of nickel doped cobalt ferrite nanoparticles Ni{sub x}Co{sub 1−x}Fe{sub 2}O{sub 4} (x=0.5, 0.75, 0.9) derived by the chemical co-precipitation route are characterized by XRD, FTIR, TEM, EPR, search coil and ac susceptibility techniques to develop stable kerosene based ferrofluid. XRD patterns and TEM images confirm the single phase formation of Ni{sub x}Co{sub 1-x}Fe{sub 2}O{sub 4} nanoparticles whose crystallite size increases and lattice parameters decreases with the increase in Ni content. EPR resonance signal peak-to-peak line width and resonance field value decreases with the increase in Ni concentration in these samples. The broad nature of resonance signal is attributed to the ferromagnetic nature of the as-prepared nanoparticles and the increase in super exchange interaction among Ni{sup 2+}-O-Co{sup 2+} facilitate the shifting of resonance value to lower field. The hysteresis loops of these nickel doped cobalt ferrite analogs exhibits highly magnetic nature of these nanoparticles at ambient temperature whose saturation magnetization, coerecivity and remanence magnetization decreases linearly with the increase in Ni-concentration in cobalt ferrite. The magnetic susceptibility with temperature curve shows increasing trend of blocking temperature with rise in nickel ion concentration. - Graphical abstract: Magnetic Characteristics variation in Nickel Doped cobalt ferrite nanoparticles with nickel content through structural and morphological correlation. - Highlights: • Nickel doped Cobalt ferrite nanoparticles (NPs) synthesis by the co-precipitation route. • Explored magnetic properties variation with nickel content. • Lattice parameter decreases and crystallite size increases with Ni{sup 2+} content. • NPs Ferromagnetic nature is confirmed by EPR and search coil studies. • Magnetocrystalline anisotropy of Ni{sup 2+} ions increases blocking temperature.

  8. The magnetic and oxidation behavior of bare and silica-coated iron oxide nanoparticles synthesized by reverse co-precipitation of ferrous ion (Fe{sup 2+}) in ambient atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Mahmed, N., E-mail: norsuria.mahmed@aalto.fi [Aalto University School of Chemical Technology, Department of Materials Science and Engineering, P.O. Box 16200, FI-00076 Aalto (Finland); School of Materials Engineering, Kompleks Pusat Pengajian UniMAP, Taman Muhibbah, Universiti Malaysia Perlis, 02600 Jejawi, Perlis (Malaysia); Heczko, O., E-mail: heczko@fzu.cz [Institute of Physics, Academy of Sciences, Czech Republic Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Lancok, A., E-mail: Lancok@seznam.cz [Institute of Physics, Academy of Sciences, Czech Republic Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Hannula, S-P., E-mail: simo-pekka.hannula@aalto.fi [Aalto University School of Chemical Technology, Department of Materials Science and Engineering, P.O. Box 16200, FI-00076 Aalto (Finland)

    2014-03-15

    The synthesis of iron oxide nanoparticles, i.e., magnetite was attempted by using only ferrous ion (Fe{sup 2+}) as a magnetite precursor, under an ambient atmosphere. The room temperature reverse co-precipitation method was used, by applying two synthesis protocols. The freshly prepared iron oxide was also immediately coated with Stöber silica (SiO{sub 2}) layer, forming the coreshell structure. The phase, stoichiometry, crystallite and the particle size of the synthesized powders were determined by using X-ray diffraction (XRD) and transmission electron microscope (TEM), while the magnetic and oxidation behaviors were studied by using the vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. Based on the results, the bare iron oxide nanoparticles are in the stoichiometry between the magnetite and the maghemite stoichiometry, i.e., oxidation occurs. This oxidation is depending on the synthesis protocols used. With the silica coating, the oxidation can be prevented, as suggested by the fits of Mössbauer spectra and low temperature magnetic measurement. - Highlights: • Synthesis of magnetite was attempted by using ferrous ion (Fe{sup 2+}) in air. • The synthesized particle has a stoichiometry in between magnetite and maghemite. • Silica shell partly prevented the oxidation as suggested by magnetic and Mössbauer study.

  9. Phase formation, morphology and magnetic properties of MgFe{sub 2}O{sub 4} nanoparticles synthesized by hydrothermal technique

    Energy Technology Data Exchange (ETDEWEB)

    Nonkumwong, Jeeranan [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Ananta, Supon [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Jantaratana, Pongsakorn [Department of Physics, Faculty of Science, Kasetsart University, Bangkok 11900 (Thailand); Phumying, Santi; Maensiri, Santi [Advanced Materials Physics Laboratory (Amp.), School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Srisombat, Laongnuan, E-mail: slaongnuan@yahoo.com [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-05-01

    In the present work, the processing conditions for obtaining monodispersed magnesium ferrite (MgFe{sub 2}O{sub 4}) nanoparticles with the desired morphology and relatively high saturation magnetization via hydrothermal technique were developed. For the first time, the effects of base type and reaction conditions (i.e. temperature and time) on phase formation, morphology and magnetic properties of the obtained products were determined by using a combination of XRD, TEM/EDX and VSM techniques. It is seen that the saturation magnetization of the particles can be increased by employing lower reaction temperature and/or shorter reaction time, while narrow size distribution of the particles can be maintained. In addition, it was found that pure phase of superparamagnetic MgFe{sub 2}O{sub 4} nanoparticles with the smallest size of about 65 nm was obtained by using CH{sub 3}COONa as a base at 180 °C for 14 h. - Highlights: • Preparation of MgFe{sub 2}O{sub 4} nanoparticles by hydrothermal method. • Effects of base and reaction conditions on formation and morphology MgFe{sub 2}O{sub 4} particles. • Producing the 65 nm MgFe{sub 2}O{sub 4} nanoparticles with superparamagnetic property.

  10. In vitro antioxidant and hepatoprotective potential of Azolla microphylla phytochemically synthesized gold nanoparticles on acetaminophen - induced hepatocyte damage in Cyprinus carpio L.

    Science.gov (United States)

    Kunjiappan, Selvaraj; Bhattacharjee, Chiranjib; Chowdhury, Ranjana

    2015-06-01

    The present study aims to evaluate the hepatoprotective and antioxidant effects of gold nanoparticles (GNaP) biosynthesized through the mediation of Azolla microphylla and A. microphylla extract on acetaminophen-induced hepatocyte damage in common carp fish (Cyprinus carpio L.). The gold nanoparticles (100, 150, 200 μg/ml) and A. microphylla extract powder (100, 200, 400 μg/ml) were added to the primary hepatocytes in different conditions: treatment I (before 12 mM acetaminophen), treatment II (after 12 mM acetaminophen), and treatment III (both before and after 12 mM acetaminophen), and incubated. Among these, control group treated with 12 mM acetaminophen produced significantly elevated levels (50-80%) of lactate dehydrogenase (LDH), catalase (CAT), glutamate oxalate transaminase (GOT), glutamate pyruvate transaminase (GPT), and malondialdehyde (MDA), and significantly decreased the levels (60-75%) of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Treatment with methanol extract of A. microphylla phytochemically biosynthesized gold nanoparticles (100, 150, 200 μg/ml) and A. microphylla methanol extract powder (100, 200, 400 μg/ml) significantly improved the viability of cells in a culture medium. It also significantly reduced the levels of LDH, CAT, GOT, GPT, and MDA, and significantly increased the levels of SOD and GSH-Px. In conclusion, gold nanoparticles biosynthesized through A. microphylla demonstrated effective hepatoprotective and antioxidant effects than methanol extract of A. microphylla. PMID:25862331

  11. Crystal structure of superparamagnetic Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4} nanoparticles synthesized by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Escamilla-Pérez, A.M., E-mail: angel.mep@gmail.com [Cinvestav-Unidad Saltillo, Industria Metalúrgica No. 1062, Parque Industrial Saltillo-Ramos Arizpe, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Cortés-Hernández, D.A., E-mail: dora.cortes@cinvestav.edu.mx [Cinvestav-Unidad Saltillo, Industria Metalúrgica No. 1062, Parque Industrial Saltillo-Ramos Arizpe, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Almanza-Robles, J.M. [Cinvestav-Unidad Saltillo, Industria Metalúrgica No. 1062, Parque Industrial Saltillo-Ramos Arizpe, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Mantovani, D.; Chevallier, P. [Laboratory for Biomaterials and Bioengineering, Department of Materials Engineering and University Hospital Research Center, Laval University, Quebec City, QC (Canada)

    2015-01-15

    Powders of magnetic iron oxide nanoparticles (Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4}) were prepared by a sol–gel method using ethylene glycol and nitrates of Fe, Ca and Mg as starting materials. Those powders were heat treated at different temperatures (573, 673, 773 and 873 K). In order to evaluate the effect of the heat treatment temperature on the nanoferrites properties, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques were used. It was found that the reaction products exhibit nanometric sizes and superparamagnetic behavior. It is also demonstrated that, as the heat treatment temperature increases, the particle size and the saturation magnetization of the nanoferrites are increased. - Highlights: • Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4} superparamagnetic nanoparticles were successfully synthesized. • Particle average sizes of Ca–Mg ferrites were within the range of 8–25 nm. • The nanoferrite treated at 873 K showed a stoichiometry close to Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4}. • The heat treatment temperature has a strong effect on the crystal structure. • These nanoparticles are potential materials for magnetic hyperthermia.

  12. Structural, magnetic and dielectric properties of Ni(1_x)Zn(x)Fe2O4 (x = 0,0.5 and 1) nanoparticles synthesized by chemical co-precipitation method.

    Science.gov (United States)

    Rathore, Deepshikha; Kurchania, Rajnish; Pandey, R K

    2013-03-01

    Ni(1-x)Zn(x)Fe2O4 (x = 0, 0.5 and 1) ferrite nanoparticles were synthesized by chemical co-precipitation method. X-ray diffraction technique and Rietveld refinement were used to investigate the structural characteristics and determination of the particle size which was found to decrease from 4.9 to 4.1 nm as a function of increasing Zn from 0 to 1.0. Vibrating sample magnetometer was used to study magnetic properties of nickel zinc ferrite nanoparticles. Field-dependent magnetization measurements (M-H curve) at 300 K revealed that Zn substitutions on inverse spinel nickel ferrites enhance the magnetic properties. Magnetization as a function of temperature showed the superparamagnetic behavior of Ni(1-x)Zn(x)Fe2O4 (x = 0,0.5 and 1) nanoparticles. Dielectric permittivity and a.c. conductivity were measured as a function of frequency from 100 kHz to 1 MHz at certain temperatures. The observed response in a.c. conductivity as a function of log of frequency of these nickel zinc ferrite systems was believed to be due to the presence of Maxwell-Wagner type interfacial polarization and hopping of electron by means of quantum mechanical tunneling. PMID:23755597

  13. A new attitude to environment: Preparation of an efficient electrocatalyst for methanol oxidation based on Ni-doped P zeolite nanoparticles synthesized from stem sweep ash

    International Nuclear Information System (INIS)

    Graphical abstract: - Abstract: Amorphous silica powder was extracted from stem sweep (SS) which grows in the southern parts of the Caspian Sea (Mazandran province, Iran) and used in the preparation of P zeolite nanoparticles. X-ray diffraction, scanning electronic microscopy, transmission electron microscopy and FT-IR techniques were used to characterize P zeolite nanoparticles. SEM and TEM showed the presence of nearly spherical nanoparticles with sizes in the nanometer range. Ni2+ ions could introduced into the pores of P zeolite nanoparticles through exchange with Na+ ions to modify zeolite and improve their electrochemical properties. To surmount the overvoltage of methanol oxidation on carbon paste electrode (CPE), Ni (II)-doped P zeolite (Ni/P) mixed with CPE was used as modified electrode (Ni/P-CPE). Electrochemical techniques such as cyclic voltammetry and chronoamperometry were applied to modified electrode in order to investigate the role of zeolite in electrocatalytic process of methanol oxidation. The current intensity of methanol oxidation increases impressively on Ni/P-CPE in the presence of methanol and in comparison with CPE that means the catalyst can reduce the overvoltage of methanol oxidation. Ni/P nanoparticles provide the active sites on modified electrode to catalyze the oxidation of methanol in alkaline solution. Some parameters such as potential scan rates and methanol concentration investigated to describe the mechanism of catalysis of methanol oxidation on Ni/P. In contrast to some expensive materials such as noble metals, Ni-doped P zeolite play effective role in reduction of methanol oxidation overvoltage by some valuable advantage such as inexpensive and environmentally friend nature and simplicity of preparation

  14. nanoparticles

    Science.gov (United States)

    Andreu-Cabedo, Patricia; Mondragon, Rosa; Hernandez, Leonor; Martinez-Cuenca, Raul; Cabedo, Luis; Julia, J. Enrique

    2014-10-01

    Thermal energy storage (TES) is extremely important in concentrated solar power (CSP) plants since it represents the main difference and advantage of CSP plants with respect to other renewable energy sources such as wind, photovoltaic, etc. CSP represents a low-carbon emission renewable source of energy, and TES allows CSP plants to have energy availability and dispatchability using available industrial technologies. Molten salts are used in CSP plants as a TES material because of their high operational temperature and stability of up to 500°C. Their main drawbacks are their relative poor thermal properties and energy storage density. A simple cost-effective way to improve thermal properties of fluids is to dope them with nanoparticles, thus obtaining the so-called salt-based nanofluids. In this work, solar salt used in CSP plants (60% NaNO3 + 40% KNO3) was doped with silica nanoparticles at different solid mass concentrations (from 0.5% to 2%). Specific heat was measured by means of differential scanning calorimetry (DSC). A maximum increase of 25.03% was found at an optimal concentration of 1 wt.% of nanoparticles. The size distribution of nanoparticle clusters present in the salt at each concentration was evaluated by means of scanning electron microscopy (SEM) and image processing, as well as by means of dynamic light scattering (DLS). The cluster size and the specific surface available depended on the solid content, and a relationship between the specific heat increment and the available particle surface area was obtained. It was proved that the mechanism involved in the specific heat increment is based on a surface phenomenon. Stability of samples was tested for several thermal cycles and thermogravimetric analysis at high temperature was carried out, the samples being stable.

  15. Magnetic properties of Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} spinel ferrite nanoparticles synthesized by starch-assisted sol–gel autocombustion method and its ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Raghvendra Singh, E-mail: yadav@fch.vutbr.cz [Materials Research Centre, Brno University of Technology, Purkyňova 464/118, 61200 Brno (Czech Republic); Havlica, Jaromir [Materials Research Centre, Brno University of Technology, Purkyňova 464/118, 61200 Brno (Czech Republic); Hnatko, Miroslav; Šajgalík, Pavol [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 36 Bratislava (Slovakia); Alexander, Cigáň [Institute of Measurement Science, Slovak Academy of Sciences, Dúbravská cesta 9, SK-841 04 Bratislava (Slovakia); Palou, Martin; Bartoníčková, Eva; Boháč, Martin; Frajkorová, Františka; Masilko, Jiri; Zmrzlý, Martin; Kalina, Lukas; Hajdúchová, Miroslava; Enev, Vojtěch [Materials Research Centre, Brno University of Technology, Purkyňova 464/118, 61200 Brno (Czech Republic)

    2015-03-15

    In this article, Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (x=0.0 and 0.5) spinel ferrite nanoparticles were achieved at 800 °C by starch-assisted sol–gel autocombustion method. To further reduce the particle size, these synthesized ferrite nanoparticles were ball-milled for 2 h. X-ray diffraction patterns demonstrated single phase formation of Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (x=0.0 and 0.5) spinel ferrite nanoparticles. FE-SEM analysis indicated the nanosized spherical particles formation with spherical morphology. The change in Raman modes and relative intensity were observed due to ball milling and consequently decrease of particle size and cationic redistribution. An X-ray Photoelectron Spectroscopy (XPS) result indicated that Co{sup 2+}, Zn{sup 2+} and Fe{sup 3+} exist in octahedral and tetrahedral sites. The cationic redistribution of Zn{sup 2+} and consequently Fe{sup 3+} occurred between octahedral and tetrahedral sites after ball-milling. The change in saturation magnetization (M{sub s}) and coercivity (H{sub c}) with decrease of nanocrystalline size and distribution of cations in spinel ferrite were observed. - Highlights: • Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} spinel ferrite nanoparticles. • Starch-assisted sol–gel auto-combustion method. • Effect of ball-milling on particle size and cation distribution. • Magnetic property dependent on cations and particle size.

  16. Effect of oxidation on α″-Fe{sub 16}N{sub 2} phase formation from plasma-synthesized spherical core–shell α-Fe/Al{sub 2}O{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zulhijah, Rizka [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Nandiyanto, Asep Bayu Dani [Departemen Kimia, Fakultas Pendidikan Matematika dan Ilmu Pengetahuan Alam, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi No. 229, Bandung 40154 (Indonesia); Ogi, Takashi, E-mail: ogit@hiroshima-u.ac.jp [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Iwaki, Toru [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Nakamura, Keitaro [Research Center for Production and Technology, Nisshin Seifun Group, Inc., 5-3-1, Tsurugaoka, Fujimino, Saitama 356-8511 (Japan); Okuyama, Kikuo [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan)

    2015-05-01

    The introduction of an oxidation treatment to the synthesis of spherical and core–shell α″-Fe{sub 16}N{sub 2}/Al{sub 2}O{sub 3} nanoparticles (~62 nm) from plasma-synthesized core–shell α-Fe/Al{sub 2}O{sub 3} nanoparticles has been found to result in a high yield of α″-Fe{sub 16}N{sub 2} phase of up to 98%. The oxidation treatment leads the formation of a maghemite phase with open channeled structures along the c-axis, facilitating penetration of H{sub 2} and NH{sub 3} gases during the hydrogen reduction and nitridation steps. The saturation magnetization and magnetic coercivity of the core–shell α″-Fe{sub 16}N{sub 2}/Al{sub 2}O{sub 3} magnetic nanoparticles were found to be 156 emu/g and 1450 Oe, respectively. The detailed effects of the oxidation on the formation of α″-Fe{sub 16}N{sub 2} phase were investigated by characterizing the morphology (SEM, TEM and BET), elemental composition (EDX, EELS, and XAFS) and magnetic properties (Mössbauer and MSPS) of the prepared particles. The good magnetic properties obtained have the potential for future applications such as rare-earth-free magnetic materials. - Highlights: • High yield of α″-Fe{sub 16}N{sub 2} up to 98% was prepared from core–shell α-Fe/Al{sub 2}O{sub 3} NPs. • Introduction of oxidation improved yield of α″-Fe{sub 16}N{sub 2} for large size of NPs. • Oxidation forming microporous structured maghemite facilitated nitridation process. • Particle morphology changed during the nitrogen process due to atomic dislocation. • Core–shell α″-Fe{sub 16}N{sub 2}/Al{sub 2}O{sub 3} nanoparticles showed good magnetic performances.

  17. N-doped carbon nanotubes synthesized in high yield and decorated with CeO2 and SnO2 nanoparticles

    International Nuclear Information System (INIS)

    Graphical abstract: Highlights: · Nitrogen doped multiwalled carbon nanotubes (CNxNTs) with high yield have been prepared. · The maximum yield of the CNxNTs is 920%. · SnO2 and CeO2 nanoparticles were decorated on the surface of CNxNTs without any pre-treatment. · The SnO2/CNxNTs and the CeO2/CNxNTs have excellent activity for NO electrooxidation. - Abstract: Nitrogen doped multiwalled carbon nanotubes (CNxNTs) with high yield and purity have been successfully prepared from n-propylamine precursor with CoxMg1-xMoO4 catalyst. The maximum yield of the CNxNTs is 920%. SnO2 and CeO2 nanoparticles are decorated on the surface of CNxNTs without any acid treatment due to the inherent interface activity. The TEM images reveal that SnO2 and CeO2 nanoparticles were anchored on the surface of the CNxNTs uniformly, and the XPS results indicate that the doped nitrogen atoms of CNxNTs play significant roles in immobilizing SnO2 and CeO2 nanoparticles, and the mechanism of the composite process has been discussed. The electrooxidation performance of the composites for NO at the modified electrodes was investigated. The CNxNTs-based composites show greater activity and sensitivity than the conventional CNTs-based composites for NO electrooxidation, which render them excellent electrode materials for NO detection and other potential applications.

  18. Enhanced coagulation-photocatalytic treatment of Acid red 73 dye and real textile wastewater using UVA/synthesized MgO nanoparticles.

    Science.gov (United States)

    Jorfi, Sahand; Barzegar, Gelavizh; Ahmadi, Mehdi; Darvishi Cheshmeh Soltani, Reza; Alah Jafarzadeh Haghighifard, Nemat; Takdastan, Afshin; Saeedi, Reza; Abtahi, Mehrnoosh

    2016-07-15

    Sequencing coagulation - photocatalytic degradation using UVA/MgO nanoparticles process was investigated for Acid red 73dye removal and then treatment of a real textile wastewater. Effective operational parameters including pH and coagulant and photocatalyst dosage were studied in synthetic wastewater and then the process was applied for real wastewater. Both coagulation and photocatalytic processes were pH dependent. At coagulant dosage of 200 mg/L and initial pH of 6, the dye concentration decreased from 200 to 31 mg/L. Complete removal of AR73 was observed with MgO nanoparticles of 0.8 g/L, initial pH of 5 and reaction time of 60 min. Langmuir-Hinshelwood model was well fitted with removal results (R(2): 0.939-0.988 for different initial dye concentration). In the case of real textile wastewater, the sequence coagulation-UVA/MgO nanoparticles photocatalytic degradation yielded considerable total COD and TOC removal 98.3% and 86.9%respectively, after 300 min. PMID:27086271

  19. In-Situ Synchrotron Radiation Study of Formation and Growth of Crystalline CexZr1-xO2 Nanoparticles Synthesized in Supercritical Water

    DEFF Research Database (Denmark)

    Tyrsted, Christoffer; Becker-Christensen, Jacob; Hald, Peter;

    2010-01-01

    limited by the diffusion of monomers toward the surface. For x=0 and 0.2, the opposite behavior is observed with the growth initially being limited by diffusion (up to∼3.5 nm) and later by the surface reaction kinetics. Thus, although a continuous solid solution can be obtained for the ceria-zirconia...... system, the growth of ceria and zirconia nanoparticles is fundamentally different under supercritical water conditions. For comparison, ex situ synthesis has also been performed using an in-house supercritical flow reactor. The resulting samples were analyzed using PXRD, small-angle X-ray scattering...

  20. Study on nanoparticles synthesized from β-conglycinin-dextran conjugate products and conjugate products hydrolysates%7S-葡聚糖糖基化产物及其水解物制备纳米颗粒的研究

    Institute of Scientific and Technical Information of China (English)

    张晋博; 王丽娟; 何秀婷; 杨晓泉; 尹寿伟; 王金梅

    2013-01-01

    采用干热法制备β-伴大豆球蛋白(7S)与葡聚糖(67ku)糖基化产物.利用胰蛋白酶对糖基化产物进行限制性酶解,得到了一种具有两亲性结构的水解度(DH)为2.2%的糖基化产物水解物.利用反溶剂法制备了7S、7S-葡聚糖糖基化产物及DH为2.2%的糖基化产物水解物的纳米颗粒,并且考察了戊二醛交联和旋转蒸发去除乙醇对已形成的纳米颗粒的影响.研究了三种纳米颗粒样品的粒度,Zeta-电位和多分散性指数(PDI).实验发现,DH为2.2%的糖基化产物水解物在反溶剂过程中更容易发生自组装,形成的纳米颗粒比7S和7S-葡聚糖糖基化产物形成的纳米颗粒的粒度小、电位绝对值高、PDI值低.%The amphiphilic molecule was prepared by conjugating soy β-conglycinin and dextran(MW 67ku) under dry-heated reaction followed by trypin hydrolysis with the degree of hydrolysis(DH) at 2.2%. Nanoparticles were synthesized from β-conglycinin , β-conglycinin-dextran conjugate products and hydrolysates of β -conglycinin -dextran conjugate products DH 2.2% by desolvation method. The effect of glutaraldehyde cross-linking and removing ethanol by evaporation on the formed nanoparticles were examined. Formed nanoparticles were systematically investigated by means of particle size,zeta-potential and polydispersity index(PDI). Self-assembly could be easily occurred in the hydrolysates of β-conglycinin-dextran conjugate products DH 2.2% during desolvation process,and the formed nanoparticles had smaller particle size,much higher absolute value of zeta-potential and a significantly lower PDI compared with that of the nanoparticles formed from β-conglycinin,and β-conglycinin-dextran conjugate products.

  1. Magnetic and structural properties of RE doped Co-ferrite (REåNd, Eu, and Gd) nano-particles synthesized by co-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Amiri, S.; Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir

    2013-11-15

    Cobalt ferrite nano-particles, Co{sub 0.9}RE{sub 0.1}Fe{sub 2}O{sub 4}, with three different rare earth ions (Nd, Eu, and Gd) were prepared by the chemical co-precipitation method. X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR), and Vibrating Sample Magnetometry were carried out to study the structural and magnetic properties, respectively. The XRD results revealed that the crystal size is about 22 nm for Gd–Co ferrite, which is close to the particle sizes observed from TEM images (20 nm). The FTIR measurements between 350 and 4000 cm{sup −1} confirmed the intrinsic cation vibrations of the spinel structure. The results showed that the RE ions increase both vibrational frequencies and bond strength. The magnetic results showed that the highest magnetic coercivity and the loop area correspond to the Gd–Co ferrite, making it suitable for hyperthermia treatment. Also, the Curie point was decreased by the RE ions and had its lowest value for Nd–Co ferrite (336 °C). - Highlights: • Magnetic and structural studies of RE{sup 3+}–Co-ferrite (RE=Nd, Gd, and Eu) are investigated. • Simple co-precipitation method involving less energy and low-cost is used. • Nanoparticles with high coercivity, magnetization and loop area are obtained. • The obtained particles are used in nanomedicine applications like hyperthermia.

  2. CURRENT SITUATION OF ZnO NANOPARTICLE SYNTHESES BY TEMPLATE METHOD%纳米氧化锌的模板法制备现状

    Institute of Scientific and Technical Information of China (English)

    张宁; 李锋锋; 武子瀚; 李娟娟; 王庆辉; 勾好竹

    2012-01-01

    The size, structure and morphology ol ZnO nanoparticles can be effectively controlled by the spatial confinement and regulation of the template, because of the abundant internal structures of template materials. In this paper, the basic principle, preparation method, application fields and developing trends of template method for preparing ZnO nanoparticle were elaborated. Simultaneously, some suggestionis and ideas were proposed.%模板材料的内部结构是十分丰富的,利用模板材料中空隙的空间限制作用和模板的调控作用便可有效地控制纳米氧化锌材料的尺寸、结构、形貌等特征。文章主要对几种特殊模板法合成纳米氧化锌材料的基本原理、合成工艺及其相关的应用领域和发展前景进行了阐述,并提出了一些相关的建议和想法。

  3. Eco-friendly control of malaria and arbovirus vectors using the mosquitofish Gambusia affinis and ultra-low dosages of Mimusops elengi-synthesized silver nanoparticles: towards an integrative approach?

    Science.gov (United States)

    Subramaniam, Jayapal; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Kovendan, Kalimuthu; Madhiyazhagan, Pari; Kumar, Palanisamy Mahesh; Dinesh, Devakumar; Chandramohan, Balamurugan; Suresh, Udaiyan; Nicoletti, Marcello; Higuchi, Akon; Hwang, Jiang-Shiou; Kumar, Suresh; Alarfaj, Abdullah A; Munusamy, Murugan A; Messing, Russell H; Benelli, Giovanni

    2015-12-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. However, the use of synthetic insecticides to control Culicidae may lead to high operational costs and adverse non-target effects. Plant-borne compounds have been proposed for rapid extracellular synthesis of mosquitocidal nanoparticles. Their impact against biological control agents of mosquito larval populations has been poorly studied. We synthesized silver nanoparticles (AgNP) using the aqueous leaf extract of Mimusops elengi as a reducing and stabilizing agent. The formation of AgNP was studied using different biophysical methods, including UV-vis spectrophotometry, TEM, XRD, EDX and FTIR. Low doses of AgNP showed larvicidal and pupicidal toxicity against the malaria vector Anopheles stephensi and the arbovirus vector Aedes albopictus. AgNP LC50 against A. stephensi ranged from 12.53 (I instar larvae) to 23.55 ppm (pupae); LC50 against A. albopictus ranged from 11.72 ppm (I) to 21.46 ppm (pupae). In the field, the application of M. elengi extract and AgNP (10 × LC50) led to 100 % larval reduction after 72 h. In adulticidal experiments, AgNP showed LC50 of 13.7 ppm for A. stephensi and 14.7 ppm for A. albopictus. The predation efficiency of Gambusia affinis against A. stephensi and A. albopictus III instar larvae was 86.2 and 81.7 %, respectively. In AgNP-contaminated environments, predation was 93.7 and 88.6 %, respectively. This research demonstrates that M. elengi-synthesized AgNP may be employed at ultra-low doses to reduce larval populations of malaria and arbovirus vectors, without detrimental effects on predation rates of mosquito natural enemies, such as larvivorous fishes.

  4. Effect of sonochemical synthesized TiO2 nanoparticles and coagulation bath temperature on morphology, thermal stability and pure water flux of asymmetric cellulose acetate membranes prepared via phase inversion method

    Directory of Open Access Journals (Sweden)

    Abedini Reza

    2012-01-01

    Full Text Available In this study, asymmetric pure CA and CA/ TiO2 composite membranes were prepared via phase inversion by dispersing TiO2 nanopaticles in the CA casting solutions induced by immersion precipitation in water coagulation bath. TiO2 nanoparticles, which were synthesized by the sonochemical method, were added into the casting solution with different concentrations. Effects of TiO2 nanoparticles concentration (0 wt. %, 5wt.%, 10wt.%, 15wt.%, 20wt.% and 25wt.% and coagulation bath temperature (CBT= 25°C, 50°C and 75°C on morphology, thermal stability and pure water flux (PWF of the prepared membranes were studied and discussed. Increasing TiO2 concentration in the casting solution film along with higher CBT resulted in increasing the membrane thickness, water content (WC, membrane porosity and pure water flux (PWF, also these changes facilitate macrovoids formation. Thermal gravimetric analysis (TGA shows that thermal stability of the composite membranes were improved by the addition of TiO2 nanopaticles. Also TGA results indicated that increasing CBT in each TiO2 concentration leads to the decreasing of decomposition temperature (Td of hybrid membranes.

  5. Synthesize and characterization of a novel anticorrosive cobalt ferrite nanoparticles dispersed in silica matrix (CoFe2O4-SiO2) to improve the corrosion protection performance of epoxy coating

    Science.gov (United States)

    Gharagozlou, M.; Ramezanzadeh, B.; Baradaran, Z.

    2016-07-01

    This study aimed at studying the effect of an anticorrosive nickel ferrite nanoparticle dispersed in silica matrix (NiFe2O4-SiO2) on the corrosion protection properties of steel substrate. NiFe2O4 and NiFe2O4-SiO2 nanopigments were synthesized and then characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscope (TEM). Then, 1 wt.% of nanopigments was dispersed in an epoxy coating and the resultant nanocomposites were applied on the steel substrates. The corrosion inhibition effects of nanopigments were tested by an electrochemical impedance spectroscopy (EIS) and salt spray test. Results revealed that dispersing nickel ferrite nanoparticles in a silica matrix (NiFe2O4-SiO2) resulted in the enhancement of the nanopigment dispersion in the epoxy coating matrix. Inclusion of 1 wt.% of NiFe2O4-SiO2 nanopigment into the epoxy coating enhanced its corrosion protection properties before and after scratching.

  6. Effect of palladium on gas sensing properties of Sn(Sb2O3)O2 nanoparticles synthesized by sonochemical processing at room temperature

    Science.gov (United States)

    Majumdar, Sanhita

    2016-07-01

    Palladium catalyzed Sn(Sb2O3)O2 nanoparticles prepared by the sonication assisted method exhibited a Pd dependent selectivity to butane as well as methane. Attempts have been made to correlate powder properties such as surface area, particle size, crystallite size and rate of agglomeration with sensor properties like resistance, percent sensitivity, response and recovery times. Sample with 3 wt% Pd exhibited the lowest rate of agglomeration amongst the prepared samples and around 70% sensitivity towards butane at 400 °C operating temperature. 5 wt% Pd loaded sample, on the other hand, exhibited about 98% methane sensitivity at 350 °C operating temperature. Results confirmed that either by varying the amount of palladium or by changing the operating temperature, it was possible to tune the selective sensitivity of the fabricated sensors towards either butane or methane.

  7. A two step method to synthesize palladium-copper nanoparticles on reduced graphene oxide and their extremely high electrocatalytic activity for the electrooxidation of methanol and ethanol

    Science.gov (United States)

    Na, HeYa; Zhang, Lei; Qiu, HaiXia; Wu, Tao; Chen, MingXi; Yang, Nian; Li, LingZhi; Xing, FuBao; Gao, JianPing

    2015-08-01

    Palladium-copper nanoparticles (Pd-Cu NPs) supported on reduced graphene oxide (RGO) with different Pd/Cu ratios (Pd-Cu/RGO) were prepared by a two step method. The Pd-Cu/RGO hybrids were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and thermogravimetric analyses. Cyclic voltammetry and chronoamperometry were used to investigate the electrochemical activities and stabilities of the Pd-Cu/RGO catalysts for the electro-oxidation of methanol and ethanol in alkaline media. The Pd-Cu/RGO catalysts exhibited high catalytic activities and good stabilities. This is because the catalysts have a bimetallic structure consisting of a small Pd-Cu core surrounded by a thin Pd-rich shell which improves the catalytic activities of the Pd-Cu/RGO hybrids. Thus they should be useful in direct methanol and ethanol fuel cells.

  8. Enzyme-based sensing of glucose using a glassy carbon electrode modified with a one-pot synthesized nanocomposite consisting of chitosan, reduced graphene oxide and gold nanoparticles

    International Nuclear Information System (INIS)

    A nanocomposite was prepared that consists of chitosan, reduced graphene oxide and gold nanoparticles by in-situ and simultaneous reduction of graphene oxide and hexachloroaurate whereby chitosan acts as a reducing and stabilizing agent. The nanocomposite was then deposited on a glassy carbon electrode, and glucose oxidase (GOx) was immobilized on its surface to obtain a glucose biosensor. The immobilized GOx displays fast electron transfer with a transfer rate constant of 2.80 s−1. Operated at a working voltage of −0.45 V (vs. Ag/AgCl), the sensor gives a linear response to glucose in the 0.05 to 1.2 mM concentration range, with a sensitivity of 13.58 μA mM−1 cm−2, and a 0.52 μM detection limit. The apparent Michaelis-Menten constant is 2.39 mM. It also possesses good selectivity, reproducibility and stability. (author)

  9. Ion dependence of magnetic anisotropy in MFe2O4 (M=Fe, Co, Mn) nanoparticles synthesized by high-temperature reaction

    International Nuclear Information System (INIS)

    The influence of different M2+ cations on the effective magnetic anisotropy of systems composed of MFe2O4 (M=Fe, Co and Mn) nanoparticles was investigated. Samples were prepared by the high-temperature (538 K) solution phase reaction of Fe (acac)3, Co (acac)2 and Mn (acac)2 with 1,2 octanodiol in the presence of oleic acid and oleylamine. The final particles are coated by an organic layer of oleic acid that prevents agglomeration. Transmission electron microscopy (TEM) images show that particles present near spherical form and a narrow grain size distribution, with mean diameters in the range of 4.5-7.6 nm. Powder samples were analyzed by ac susceptibility and Moessbauer measurements, and Keff for all samples was evaluated using both techniques, showing a strong dependence on the nature of the divalent cation

  10. Structural, magnetic and electronic properties of Fe1+xGa2-xO4 nanoparticles synthesized by the combustion method.

    Science.gov (United States)

    Lyubutin, I S; Starchikov, S S; Gervits, N E; Lin, Chun-Rong; Tseng, Yaw-Teng; Shih, Kun-Yauh; Lee, Jiann-Shing; Ogarkova, Yu L; Korotkov, N Yu

    2016-08-10

    The combustion method was used to prepare a precursor powder of an iron-gallium oxide compound which was further heat-treated in order to obtain a set of Fe1+xGa2-xO4 nanoparticles. All samples have a cubic spinel-type structure (space group Fd3[combining macron]m) and the particle size varies from 1.8 to 28.0 nm depending on the treatment conditions. From the comparative analysis by XRD, EDS, and Raman and Mössbauer spectroscopy the creation of a new spinel phase γ-FeGaO3, which was mainly located on the particle surface, was established. As a result, the composition consists of a FeGa2O4 core covered by a FeGaO3 shell. The relative content of FeGa2O4/FeGaO3 compounds in the composites can be varied by heat treatment. The maximum in the ZFC magnetization curves appeared in all samples at about 20-30 K corresponding to the spin-freezing temperature Tsg, which is much higher than in the bulk compound with a pure inverse spinel structure (Ga)[FeGa]O4. The values of effective Curie temperature ΘC for the Fe1+xGa2-xO4 nanoparticles are rather high and positive, indicating a ferromagnetic interaction between iron ions. The high values of the magnetic frustration parameter f = ΘC/Tsg (up to 7) indicate a high degree of magnetic frustration. The low temperature Mössbauer data reveal the magnetic ordering of Fe ions in all samples with the magnetic transition at about 20-26 K depending on the particle size. The specific features of the Mössbauer parameters indicate the properties of non-homogeneous magnetic systems with frustrated interactions specific to spin-glasses. The magnetic system behaves as a spin-glass below Tsg and it is superparamagnetic above Tsg. Such a system is called a "super-spin-glass". The anisotropy energy Eanis strongly depends on the content of Fe(2+) and Fe(3+) ions which contribute to the magnetocrystalline Ecryst and exchange Eex anisotropies, respectively. The anisotropy energy can be tuned by variation of the content of the (FeGaO3)-(FeGa2

  11. Revitalizing the Frens Method To Synthesize Uniform, Quasi-Spherical Gold Nanoparticles with Deliberately Regulated Sizes from 2 to 330 nm.

    Science.gov (United States)

    Xia, Haibing; Xiahou, Yujiao; Zhang, Peina; Ding, Wenchao; Wang, Dayang

    2016-06-14

    In this work, we have successfully developed a new and consistent model to describe the growth of gold nanoparticles (Au NPs) via citrate reduction of auric acid (HAuCl4) by carefully assessing the temporal evolution of the NP sizes and surface charges by means of dynamic light scattering (DLS) and zeta-potential measurements. The new model demonstrates that the nucleation and growth of the Au NPs occur exclusively in the particles of the complexes of Au(+) ions and sodium acetone dicarboxylate (SAD) derived from the citrate/HAuCl4 redox reaction, which proceeds as described by the classic LaMer model. Concomitant with the Au NP growing therein, the Au(+)/SAD complex particles undergo reversible agglomeration with the reaction time, which may result in an abnormal color change of the reaction media but have little impact on the Au NP growth. Built on the new model, we have successfully produced monodisperse quasi-spherical Au NPs with sizes precisely regulated from 2 to 330 nm via simple citrate reduction in a one-pot manner. To date, highly uniform Au NPs with sizes spanning such a large size range could not be formed otherwise even via deliberately controlled seeded growth methods. PMID:27263542

  12. Morphology of hydrothermally synthesized ZnO nanoparticles tethered to carbon nanotubes affects electrocatalytic activity for H2O2 detection

    Science.gov (United States)

    Wayu, Mulugeta B.; Spidle, Ryan T.; Devkota, Tuphan; Deb, Anup K.; Delong, Robert K.; Ghosh, Kartik C.; Wanekaya, Adam K.; Chusuei, Charles C.

    2013-01-01

    We describe the synthesis of zinc oxide (ZnO) nanoparticles and demonstrate their attachment to multiwalled carbon tubes, resulting in a composite with a unique synergistic effect. Morphology and size of ZnO nanostructures were controlled using hydrothermal synthesis, varying the hydrothermal treatment temperature, prior to attachment to carboxylic acid functionalized multi-walled carbon nanotubes for sensing applications. A strong dependence of electrocatalytic activity on nanosized ZnO shape was shown. High activity for H2O2 reduction was achieved when nanocomposite precursors with a roughly semi-spherical morphology (no needle-like particles present) formed at 90 °C. A 2.4-fold increase in cyclic voltammetry current accompanied by decrease in overpotential from the composites made from the nanosized, needle-like-free ZnO shapes was observed as compared to those composites produced from needle-like shaped ZnO. Electrocatalytic activity varied with pH, maximizing at pH 7.4. A stable, linear response for H2O2 concentrations was observed in the 1–20 mM concentration range. PMID:25684785

  13. Effect of annealing temperature on antimicrobial and structural properties of bio-synthesized zinc oxide nanoparticles using flower extract of Anchusa italica.

    Science.gov (United States)

    Azizi, Susan; Mohamad, Rosfarizan; Bahadoran, Azadeh; Bayat, Saadi; Rahim, Raha Abdul; Ariff, Arbakariya; Saad, Wan Zuhainis

    2016-08-01

    The use of nontoxic biological compounds in the synthesis of nanomaterials is an economic and eco-friendly approach. The present work was undertaken to develop zinc oxide nanoparticles (ZnO-NPs) by a green method using simple precursor from the solution consisting of zinc acetate and the flower extract of Anchusa italica (A. italica). Effect of annealing temperature on structural and antimicrobial properties was investigated. The crystalline structure of ZnO-NPs was shown using X-ray diffraction (XRD) analysis. Transmission electron microscopy (TEM) results showed that ZnO-NPs are hexagonal in shapes with mean particle size of ~8 and ~14nm at 100°C and 200°C annealing temperatures respectively. The optical band gap was increased from 3.27eV to 3.30eV with the decreasing of the particle size. The antimicrobial activity of ZnO-NPs towards Gram positive (Bacillus megaterium and Stapphylococcus aureus) and Gram negative (Escherichia coli and Salmonella typhimurium) pathogens decreased with the increasing of the heat treating temperature. In vitro cytotoxicity studies on Vero cells, a dose dependent toxicity with non-toxic effect of concentration below 142μg/mL was shown. The results indicated that A. italica is an appropriate reaction media to prepare ZnO-NPs for cosmetic and bio-medical productions. PMID:27318600

  14. Mesoporous carbon stabilized MgO nanoparticles synthesized by pyrolysis of MgCl2 preloaded waste biomass for highly efficient CO2 capture.

    Science.gov (United States)

    Liu, Wu-Jun; Jiang, Hong; Tian, Ke; Ding, Yan-Wei; Yu, Han-Qing

    2013-08-20

    Anthropogenic CO2 emission makes significant contribution to global climate change and CO2 capture and storage is a currently a preferred technology to change the trajectory toward irreversible global warming. In this work, we reported a new strategy that the inexhaustible MgCl2 in seawater and the abundantly available biomass waste can be utilized to prepare mesoporous carbon stabilized MgO nanoparticles (mPC-MgO) for CO2 capture. The mPC-MgO showed excellent performance in the CO2 capture process with the maximum capacity of 5.45 mol kg(-1), much higher than many other MgO based CO2 trappers. The CO2 capture capacity of the mPC-MgO material kept almost unchanged in 19-run cyclic reuse, and can be regenerated at low temperature. The mechanism for the CO2 capture by the mPC-MgO was investigated by FTIR and XPS, and the results indicated that the high CO2 capture capacity and the favorable selectivity of the as-prepared materials were mainly attributed to their special structure (i.e., surface area, functional groups, and the MgO NPs). This work would open up a new pathway to slow down global warming as well as resolve the pollution of waste biomass.

  15. Effect of surfactant/water ratio and reagents' concentration on size distribution of manganese carbonate nanoparticles synthesized by microemulsion mediated route

    Science.gov (United States)

    Granata, Giuseppe; Pagnanelli, Francesca; Nishio-Hamane, Daisuke; Sasaki, Takehiko

    2015-03-01

    In this work nanoparticles of manganese carbonate were produced by microemulsion-mediated route at room temperature, without any post-thermal treatment. All produced samples were characterized by XRD and by TEM and obtained images were analyzed in order to evaluate particle size distribution, mean size and polydispersity (variance). The influence of water-surfactant molar ratio and concentration of reagents were investigated in the range 5-7.5 and 0.25-1.0 M, respectively, according to factorial design. Significant effects on particle mean size and polydispersity were assessed by statistical analysis. Results showed that by increasing the water-surfactant molar ratio from 5 to 7.5, the average particle size increased from less than 10 nm to around 100 nm, and the standard deviation increased from less than 5 nm to 35 nm. Statistical analysis put in evidence that water-surfactant molar ratio has significant positive effect on both mean and variance of particle size. Concentration of reactants, in the investigated range, did not influence mean size of particles, while significant changes of variance were observed: passing from 0.25 to 1 M concentration, variances of particle size increased for w = 5 and for w = 6.25, while decreased for w = 7.5.

  16. Eco-friendly drugs from the marine environment: spongeweed-synthesized silver nanoparticles are highly effective on Plasmodium falciparum and its vector Anopheles stephensi, with little non-target effects on predatory copepods.

    Science.gov (United States)

    Murugan, Kadarkarai; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Madhiyazhagan, Pari; Hwang, Jiang-Shiou; Wang, Lan; Dinesh, Devakumar; Suresh, Udaiyan; Roni, Mathath; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-08-01

    Mosquitoes act as vectors of devastating pathogens and parasites, representing a key threat for millions of humans and animals worldwide. The control of mosquito-borne diseases is facing a number of crucial challenges, including the emergence of artemisinin and chloroquine resistance in Plasmodium parasites, as well as the presence of mosquito vectors resistant to synthetic and microbial pesticides. Therefore, eco-friendly tools are urgently required. Here, a synergic approach relying to nanotechnologies and biological control strategies is proposed. The marine environment is an outstanding reservoir of bioactive natural products, which have many applications against pests, parasites, and pathogens. We proposed a novel method of seaweed-mediated synthesis of silver nanoparticles (AgNP) using the spongeweed Codium tomentosum, acting as a reducing and capping agent. AgNP were characterized by UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). In mosquitocidal assays, the 50 % lethal concentration (LC50) of C. tomentosum extract against Anopheles stephensi ranged from 255.1 (larva I) to 487.1 ppm (pupa). LC50 of C. tomentosum-synthesized AgNP ranged from 18.1 (larva I) to 40.7 ppm (pupa). In laboratory, the predation efficiency of Mesocyclops aspericornis copepods against A. stephensi larvae was 81, 65, 17, and 9 % (I, II, III, and IV instar, respectively). In AgNP contaminated environment, predation was not affected; 83, 66, 19, and 11 % (I, II, III, and IV). The anti-plasmodial activity of C. tomentosum extract and spongeweed-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. Fifty percent inhibitory concentration (IC50) of C. tomentosum were 51.34 μg/ml (CQ-s) and 65.17 μg/ml (CQ-r); C. tomentosum-synthesized AgNP achieved IC50 of 72.45 μg/ml (CQ-s) and 76.08

  17. Eco-friendly drugs from the marine environment: spongeweed-synthesized silver nanoparticles are highly effective on Plasmodium falciparum and its vector Anopheles stephensi, with little non-target effects on predatory copepods.

    Science.gov (United States)

    Murugan, Kadarkarai; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Madhiyazhagan, Pari; Hwang, Jiang-Shiou; Wang, Lan; Dinesh, Devakumar; Suresh, Udaiyan; Roni, Mathath; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-08-01

    Mosquitoes act as vectors of devastating pathogens and parasites, representing a key threat for millions of humans and animals worldwide. The control of mosquito-borne diseases is facing a number of crucial challenges, including the emergence of artemisinin and chloroquine resistance in Plasmodium parasites, as well as the presence of mosquito vectors resistant to synthetic and microbial pesticides. Therefore, eco-friendly tools are urgently required. Here, a synergic approach relying to nanotechnologies and biological control strategies is proposed. The marine environment is an outstanding reservoir of bioactive natural products, which have many applications against pests, parasites, and pathogens. We proposed a novel method of seaweed-mediated synthesis of silver nanoparticles (AgNP) using the spongeweed Codium tomentosum, acting as a reducing and capping agent. AgNP were characterized by UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). In mosquitocidal assays, the 50 % lethal concentration (LC50) of C. tomentosum extract against Anopheles stephensi ranged from 255.1 (larva I) to 487.1 ppm (pupa). LC50 of C. tomentosum-synthesized AgNP ranged from 18.1 (larva I) to 40.7 ppm (pupa). In laboratory, the predation efficiency of Mesocyclops aspericornis copepods against A. stephensi larvae was 81, 65, 17, and 9 % (I, II, III, and IV instar, respectively). In AgNP contaminated environment, predation was not affected; 83, 66, 19, and 11 % (I, II, III, and IV). The anti-plasmodial activity of C. tomentosum extract and spongeweed-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. Fifty percent inhibitory concentration (IC50) of C. tomentosum were 51.34 μg/ml (CQ-s) and 65.17 μg/ml (CQ-r); C. tomentosum-synthesized AgNP achieved IC50 of 72.45 μg/ml (CQ-s) and 76.08

  18. Structural studies of mechano-chemically synthesized CuIn{sub 1-x}Ga{sub x}Se{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Vidhya, B., E-mail: vidhyabhojan@gmail.com [Department of Electrical Engineering, SEES, CINVESTAV-IPN, Mexico, D.F., C.P. 07360 (Mexico); Velumani, S. [Department of Electrical Engineering, SEES, CINVESTAV-IPN, Mexico, D.F., C.P. 07360 (Mexico); Arenas-Alatorre, Jesus A. [Institute of Physics, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico, D.F. (Mexico); Morales-Acevedo, Arturo; Asomoza, R. [Department of Electrical Engineering, SEES, CINVESTAV-IPN, Mexico, D.F., C.P. 07360 (Mexico); Chavez-Carvayar, J.A. [Instituto de investigaciones en Materiales, UNAM, Mexico, D.F. (Mexico)

    2010-10-25

    CuInGaSe{sub 2} is a I-III-VI{sub 2} semiconducting material of tetragonal chalcopyrite structure. It is a very prominent absorber layer for photovoltaic devices. Particle-based coating process for CIGS is considered to be promising technique with relatively simple procedures and low initial investment. In the present work CIGS nanoparticle precursors suitable for screen-printing ink has been prepared by ball milling. High purity elemental copper granules, selenium and indium powders and fine chips of gallium were used as starting materials. First the ball milling was carried out for CuIn{sub 1-x}Ga{sub x}Se{sub 2} (x = 0.5) with (i) 10 ml of ethyl alcohol (ii) 5 ml of tetra ethylene glycol (wet) and (iii) 1 ml of ethylene diamine (semi-dry) for a milling time of 3 h and the results are not stoichiometric. In order to obtain an improved stoichiometric composition dry ball milling of elemental sources for three different compositions of CuIn{sub 1-x}Ga{sub x}Se{sub 2} (x = 0.25, 0.5 and 0.75) has been carried out. X-ray diffraction analysis revealed the presence of (1 1 2), (2 2 0)/(2 0 4), (3 1 2)/(1 1 6), (4 0 0) and (3 3 2) reflections for all the milled powders. These reflections correspond to chalcopyrite structure of CIGS. Shift in peaks towards higher value of 2{theta} is observed with the increase in Ga composition. Average grain size calculated by Scherrer's formula is found to be around 13 nm for the dry samples milled for 1.5 h and 7-8 nm for the samples wet milled for 3 h. Lattice constants 'a' and 'c' are found to decrease with the increase in concentration of Gallium. FESEM analysis revealed a strong agglomeration of the particles and the particle size varied from 11 to 30 nm for the dry-milled samples. Composition of milled powders has been studied by energy dispersive X-ray analysis. TEM analysis revealed the presence of nanocrystalline particles and SAED pattern corresponds to (1 1 2), (2 2 0)/(2 0 4), (5 1 2)/(4 1 7) and (6

  19. Characterization and mosquitocidal potential of neem cake-synthesized silver nanoparticles: genotoxicity and impact on predation efficiency of mosquito natural enemies.

    Science.gov (United States)

    Chandramohan, Balamurugan; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Madhiyazhagan, Pari; Chandirasekar, Ramachandran; Dinesh, Devakumar; Kumar, Palanisamy Mahesh; Kovendan, Kalimuthu; Suresh, Udaiyan; Subramaniam, Jayapal; Rajaganesh, Rajapandian; Aziz, Al Thabiani; Syuhei, Ban; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Wei, Hui; Benelli, Giovanni

    2016-03-01

    Mosquitoes (Diptera: Culicidae) serve as important vectors for a wide number of parasites and pathogens of huge medical and veterinary importance. Aedes aegypti is a primary dengue vector in tropical and subtropical urban areas. There is an urgent need to develop eco-friendly mosquitocides. In this study, silver nanoparticles (AgNP) were biosynthesized using neem cake, a by-product of the neem oil extraction from the seed kernels of Azadirachta indica. AgNP were characterized using a variety of biophysical methods, including UV-vis spectrophotometry, FTIR, SEM, EDX, and XRD analyses. Furthermore, the neem cake extract and the biosynthesized AgNP were tested for acute toxicity against larvae and pupae of the dengue vector Ae. aegypti. LC50 values achieved by the neem cake extract ranged from 106.53 (larva I) to 235.36 ppm (pupa), while AgNP LC50 ranged from 3.969 (larva I) to 8.308 ppm (pupa). In standard laboratory conditions, the predation efficiency of a Carassius auratus per day was 7.9 (larva II) and 5.5 individuals (larva III). Post-treatment with sub-lethal doses of AgNP, the predation efficiency was boosted to 9.2 (larva II) and 8.1 individuals (larva III). The genotoxic effect of AgNP was studied on C. auratus using the comet assay and micronucleus frequency test. DNA damage was evaluated on peripheral erythrocytes sampled at different time intervals from the treatment; experiments showed no significant damages at doses below 12 ppm. Overall, this research pointed out that neem cake-fabricated AgNP are easy to produce, stable over time, and can be employed at low dosages to reduce populations of dengue vectors, with moderate detrimental effects on non-target mosquito natural enemies. PMID:26573518

  20. Optical and magnetic properties of Fe{sub 2}O{sub 3} nanoparticles synthesized by laser ablation/fragmentation technique in different liquid media

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B.K., E-mail: bishnu.pandey750@gmail.com [Laser Spectroscopy and Nanomaterials Lab, Department of Physics (UGC-CAS), University of Allahabad, Allahabad 211002 (India); Shahi, A.K. [Laser Spectroscopy and Nanomaterials Lab, Department of Physics (UGC-CAS), University of Allahabad, Allahabad 211002 (India); Shah, Jyoti; Kotnala, R.K. [National Physical Laboratory (NPL), New Delhi (India); Gopal, Ram, E-mail: profrgopal@gmail.com [Laser Spectroscopy and Nanomaterials Lab, Department of Physics (UGC-CAS), University of Allahabad, Allahabad 211002 (India)

    2014-01-15

    Iron oxide (Fe{sub 2}O{sub 3}) bulk powder have been ablated/fragmented in different liquid medium by Nd:YAG laser beam using 1064 nm wavelength. Sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide (CTAB) and double distilled water (DDW) are used as liquid medium. Crystalline size, lattice strain, phase and structure of ablated particles have been investigated using synchrotron X-ray diffraction. Optical band gap energy of as purchased Fe{sub 2}O{sub 3} found 1.92 eV that increased to 2.03 eV after ablation in CTAB determined by UV–vis absorption spectroscopy. Magnetic properties have been analyzed by hysteresis loops using vibrating sample magnetometer (VSM). Crystalline sizes have been found in the range of 29.23–16.54 nm and coercivity tailored in the range of 206.91–298.36 Oe using laser ablation. Saturation magnetization and remanence have been found in the range of 0.013–3.41 emu/g and 0.0023–.0.51 emu/g respectively. Particle shape and size have been examined by scanning electron microscopy (SEM). CTAB (cationic) and SDS (anionic) surfactants are used as capping agent. CTAB produces phase transformation in ablated iron oxide (Fe{sub 2}O{sub 3}). Crystallinity and crystalline size of ablated particles in DDW increased due to presence of rich oxygen in it due to oxidation. Ablated Fe{sub 2}O{sub 3} nanoparticles have been widely used experimentally for numerous in vivo applications such as MRI contrast enhancement agent, tissue repair, immunoassay, detoxification of biological fluids, hyperthermia, drug delivery and cell separation.

  1. Characterization and mosquitocidal potential of neem cake-synthesized silver nanoparticles: genotoxicity and impact on predation efficiency of mosquito natural enemies.

    Science.gov (United States)

    Chandramohan, Balamurugan; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Madhiyazhagan, Pari; Chandirasekar, Ramachandran; Dinesh, Devakumar; Kumar, Palanisamy Mahesh; Kovendan, Kalimuthu; Suresh, Udaiyan; Subramaniam, Jayapal; Rajaganesh, Rajapandian; Aziz, Al Thabiani; Syuhei, Ban; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Wei, Hui; Benelli, Giovanni

    2016-03-01

    Mosquitoes (Diptera: Culicidae) serve as important vectors for a wide number of parasites and pathogens of huge medical and veterinary importance. Aedes aegypti is a primary dengue vector in tropical and subtropical urban areas. There is an urgent need to develop eco-friendly mosquitocides. In this study, silver nanoparticles (AgNP) were biosynthesized using neem cake, a by-product of the neem oil extraction from the seed kernels of Azadirachta indica. AgNP were characterized using a variety of biophysical methods, including UV-vis spectrophotometry, FTIR, SEM, EDX, and XRD analyses. Furthermore, the neem cake extract and the biosynthesized AgNP were tested for acute toxicity against larvae and pupae of the dengue vector Ae. aegypti. LC50 values achieved by the neem cake extract ranged from 106.53 (larva I) to 235.36 ppm (pupa), while AgNP LC50 ranged from 3.969 (larva I) to 8.308 ppm (pupa). In standard laboratory conditions, the predation efficiency of a Carassius auratus per day was 7.9 (larva II) and 5.5 individuals (larva III). Post-treatment with sub-lethal doses of AgNP, the predation efficiency was boosted to 9.2 (larva II) and 8.1 individuals (larva III). The genotoxic effect of AgNP was studied on C. auratus using the comet assay and micronucleus frequency test. DNA damage was evaluated on peripheral erythrocytes sampled at different time intervals from the treatment; experiments showed no significant damages at doses below 12 ppm. Overall, this research pointed out that neem cake-fabricated AgNP are easy to produce, stable over time, and can be employed at low dosages to reduce populations of dengue vectors, with moderate detrimental effects on non-target mosquito natural enemies.

  2. Magnetic and electrical properties of Co1−x Cax Fe2O4 nanoparticles synthesized by the auto combustion method

    International Nuclear Information System (INIS)

    Highlights: ► Co–Ca mixed ferrite nano particles were prepared. ► The effect of adding Ca on saturation magnetization and coercivity is reported. ► Frequency and composition dependence of dielectric properties are studied too. ► This original study may be of considerable importance for materials designers. - Abstract: Nano-sized particles of Co1−x Cax Fe2O4 (x = 0.0, 0.01, 0.03, 0.05, 0.07 and 0.09) have been prepared by using the citrate-nitrate auto combustion method. X-Ray diffraction analysis has ensured the formation of the desired ferrites and has been used also to determine some of their structural properties. The particle size of only three samples has been checked out by using both transmission electron microscope (TEM) and particle size analyzer (PSA). Magnetic measurements have been performed by using vibrating sample magnetometer (VSM) at room temperature. The reduction of saturation magnetization of the nano-structured samples in comparison to bulk samples in literature and the effect of Ca addition on saturation magnetization and coercivity of all the samples are discussed. The AC conductivity and dielectric properties of these spinel ferrite nanoparticles have been investigated too as function of frequency at room temperature by using a broadband dielectric spectrometer. The AC conductivity of all the samples has been found to increase with increasing Ca substitution. This behavior is interpreted according to a suggested cationic distribution in agreement with literature and in consistency with the dielectric and loss factor results.

  3. Characterization of mechano-thermally synthesized Curie temperature-adjusted La{sub 0.8}Sr{sub 0.2}MnO{sub 3} nanoparticles coated with (3-aminopropyl) triethoxysilane

    Energy Technology Data Exchange (ETDEWEB)

    Salili, S.M. [Chemical Physics Interdisciplinary Program, Liquid Crystal Institute, Kent State University, Kent, OH 44242 (United States); School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Ataie, A., E-mail: aataie@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Barati, M.R. [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Sadighi, Z. [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

    2015-08-15

    This research aimed to synthesize nanostructured strontium-doped lanthanum manganite, La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LSMO), with its Curie temperature (T{sub c}) adjusted to the therapeutic range, through a mechanothermal route. In order to investigate the effect of heat treatment temperature and duration on the resulting crystallite size, morphology, magnetic behavior and Curie temperature, the starting powder mixture was milled in a planetary ball mill before being subsequently heat treated at distinct temperatures for different time lengths. The composition, morphology, and magnetic behavior were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and vibrating sample magnetometer (VSM). In addition, magnetic properties were further investigated using an alternating current (AC) susceptometer and thermo-magnetic analyzer. 20 h of milling produced a crystallite size reduction leading to a decrease in the heat treatment temperature of LSMO synthesis to 800 °C. Moreover, SEM analysis has shown the morphology of a strong agglomeration of fine nanoparticles. HRTEM showed clear lattice fringes of high crystallinity. The mean crystallite and particle size of 20-hour milled sample heat treated at 1100 °C for 10 h are relatively 69 and 100 nm, respectively. The VSM data at room temperature, indicated a paramagnetic behavior for samples heat treated at 800 °C. However, by increasing heat treatment temperature to 1100 °C, LSMO indicates a ferromagnetic behavior with well-adjusted Curie temperature of 320 K, suitable for hyperthermia applications. Also, reentrant spin glass (RSG) behavior has been found in heat treated samples. The particles are coated with (3-aminopropyl) triethoxysilane (APTES) for biocompatibility purposes; Fourier transform infrared spectroscopy (FTIR) and thermo

  4. Well-defined mono(η3-allyl)nickel complex MONi(η3-C3H5) (M = Si or Al) grafted onto silica or alumina: A molecularly dispersed nickel precursor for syntheses of supported small size nickel nanoparticles

    KAUST Repository

    Li, Lidong

    2014-01-01

    Preparing evenly-dispersed small size nickel nanoparticles over inert oxides remains a challenge today. In this context, a versatile method to prepare supported small size nickel nanoparticles (ca. 1-3 nm) with narrow size distribution via a surface organometallic chemistry (SOMC) route is described. The grafted mono(η3-allyl)nickel complexes MONi(η 3-C3H5) (M = Si or Al) as precursors are synthesized and fully characterized by elemental analysis, FTIR spectroscopy and paramagnetic solid-state NMR. © 2014 the Partner Organisations.

  5. Effect of Cr and Al substitution cations on the structural and magnetic properties of Ni0.6Zn0.4Fe2−xCrx/2Alx/2O4 nanoparticles synthesized using the sol–gel auto-combustion method

    International Nuclear Information System (INIS)

    The Ni0.6Zn0.4Fe2−xCrx/2Alx/2O4 (x=0–0.5) nanoparticles were prepared by employing the sol–gel auto-combustion method. The effect of aluminum and chromium on the structural and superparamagnetic properties of prepared samples was investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy, vibrating sample magnetometry (VSM), ac magnetic susceptibility and magnetization temperature curve recording in ZFC mode analysis. The XRD analysis of all synthesized samples confirmed the formation of single-phase cubic spinel structure. The results of FTIR analysis indicated that the functional groups of Ni–Zn spinel ferrite were formed during the auto-combustion sol–gel process. Moreover, FE-SEM and TEM micrographs demonstrated that nanoparticles with narrow size distribution were obtained. According to VSM results by increasing substitution contents, saturation magnetization decreased. Magnetic dynamics of the samples was studied by measuring ac magnetic susceptibility versus temperature at different frequencies. The phenomenological Néel–Brown and Vogel–Fulcher models were employed to distinguish between the interacting or noninteracting system. Results exhibited that there is a strong interaction between nanoparticles. A frequency–dependence peak was observed in ac magnetic susceptibility versus temperature for nanoparticles which is well fitted by the Vogel–Fulcher model. It is confirmed that there is strong magnetic interaction among prepared nanoparticles. - Highlights: • The hysteresis curves of the Ni0.6Zn0.4Fe2−xCrx/2Alx/2O4 nanoparticles exhibited the reduction of saturation magnetization with an increase in substitution value. • The good agreement between the susceptibility data and the Vogel–Fulcher model confirms the existence of strong interactions between nanoparticles. • The values of blocking temperature have

  6. Preparation of Gold Nanoparticles Protected with Polyelectrolyte

    Institute of Scientific and Technical Information of China (English)

    Xu Ping SUN; Zhe Ling ZHANG; Bai Lin ZHANG; Xian Dui DONG; Shao Jun DONG; Er Kang WANG

    2003-01-01

    Gold nanoparticles were synthesized through the reduction of tetrachlorauric acid (HAuCl4) by NaBH4, with polyethyleneimine(PEI) as stabilizer. The nanoparticles were characterized by UV-vis spectroscopy and atomic force microscopy(AFM).

  7. Green Synthesis of Gold Nanoparticles

    OpenAIRE

    Hamid Reza Ghorbani

    2015-01-01

    There is an increased interest in understanding the toxicity and rational design of gold nanoparticles for biomedical applications in recent years. In this study gold nanoparticles were synthesized using dextrose as a reducing agent. The gold nanoparticles displayed characteristic Surface Plasmon Resonance peak at around 550 nm having a mean particle size of 75±30 nm. In order to identify and analyze nanoparticles, UV–Vis spectroscopy, Scanning electron microscopy (SEM), and dynamic light sca...

  8. Recording-media-related morphology and magnetic properties of crystalline CoPt{sub 3} and CoPt{sub 3}-Au core-shell nanoparticles synthesized via reverse microemulsion

    Energy Technology Data Exchange (ETDEWEB)

    Bahmanrokh, Ghazaleh, E-mail: ghazalehbahmanrokh@yahoo.com; Hashim, Mansor; Matori, Khamirul Amin; Kanagesan, Samikannu; Sabbaghizadeh, Rahim; Ezzad Shafie, Mohd Shamsul [Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Navasery, Manizheh; Soltani, Nayereh [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Vaziri, Parisa [Department of Medical Physics and Biomedical Engineering, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-09-07

    A comparative experimental study of the magnetic properties of CoPt{sub 3} and CoPt{sub 3}/Au nanoparticles as well as a detailed study of the structural properties of the samples by X-ray diffraction, Transmission electron microscopy, and vibrating sample magnetometer is presented in this work. In addition, the effect of particle size on the structure and magnetic properties of nanoparticles prepared by microemulsion is studied. The correlation between particle size, crystallinity, and magnetization was studied as well. CoPt nanoparticles have been studied intensively over the last decade because of their increased magnetic anisotropy in the ordered phase that can be interesting for high density magnetic recording. A significant high coercivity for as-prepared CoPt{sub 3} and CoPt{sub 3}-Au nanoparticles was obtained at room temperature and enhanced after annealing. The focused aim of our study is to obtain high coercivity at room temperature that follows the Curie-Weiss law. This indicates an interacting system in which the nanoparticles behave like single domain ferromagnetic materials in the particle size range of 8 to 35 nm. In addition, the interaction increases by cooling the samples to low temperature around 15 K. Temperature dependence 1/M graph was obtained to investigate the behavior of nanoparticles at low temperature and shows the best fit with Curie-Weis mode.

  9. Effect of Cr and Al substitution cations on the structural and magnetic properties of Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2−x}Cr{sub x/2}Al{sub x/2}O{sub 4} nanoparticles synthesized using the sol–gel auto-combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, Ali, E-mail: ali13912001@yahoo.com; Ekhlasi, Sima; Mousavinia, Mohammad

    2014-03-15

    The Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2−x}Cr{sub x/2}Al{sub x/2}O{sub 4} (x=0–0.5) nanoparticles were prepared by employing the sol–gel auto-combustion method. The effect of aluminum and chromium on the structural and superparamagnetic properties of prepared samples was investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy, vibrating sample magnetometry (VSM), ac magnetic susceptibility and magnetization temperature curve recording in ZFC mode analysis. The XRD analysis of all synthesized samples confirmed the formation of single-phase cubic spinel structure. The results of FTIR analysis indicated that the functional groups of Ni–Zn spinel ferrite were formed during the auto-combustion sol–gel process. Moreover, FE-SEM and TEM micrographs demonstrated that nanoparticles with narrow size distribution were obtained. According to VSM results by increasing substitution contents, saturation magnetization decreased. Magnetic dynamics of the samples was studied by measuring ac magnetic susceptibility versus temperature at different frequencies. The phenomenological Néel–Brown and Vogel–Fulcher models were employed to distinguish between the interacting or noninteracting system. Results exhibited that there is a strong interaction between nanoparticles. A frequency–dependence peak was observed in ac magnetic susceptibility versus temperature for nanoparticles which is well fitted by the Vogel–Fulcher model. It is confirmed that there is strong magnetic interaction among prepared nanoparticles. - Highlights: • The hysteresis curves of the Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2−x}Cr{sub x/2}Al{sub x/2}O{sub 4} nanoparticles exhibited the reduction of saturation magnetization with an increase in substitution value. • The good agreement between the susceptibility data and the Vogel–Fulcher model confirms the existence of strong interactions

  10. Shaped Ir-Ni bimetallic nanoparticles for minimizing Ir utilization in oxygen evolution reaction.

    Science.gov (United States)

    Lim, Jinkyu; Yang, Sungeun; Kim, Chanyeon; Roh, Chi-Woo; Kwon, Yongwoo; Kim, Yong-Tae; Lee, Hyunjoo

    2016-04-25

    Shaped Ir-Ni bimetallic nanoparticles were synthesized and used for electrocatalytic oxygen evolution reaction (OER). The obtained bimetallic nanoparticles showed significantly enhanced Ir mass activity and durability compared with Ir nanoparticles. PMID:27034092

  11. Modification of carbon screen-printed electrodes by adsorption of chemically synthesized Bi nanoparticles for the voltammetric stripping detection of Zn(II), Cd(II) and Pb(II).

    Science.gov (United States)

    Rico, Ma Angeles Granado; Olivares-Marín, Mara; Gil, Eduardo Pinilla

    2009-12-15

    A simple procedure for the chemical synthesis of bismuth nanoparticles and subsequent adsorption on commercial screen-printed carbon electrodes offer reliable quantitation of trace zinc, cadmium and lead by anodic stripping square-wave voltammetry in nondeareated water samples. The influence of two hydrodynamic configurations (convective cell and flow cell) and the effect of various experimental variables upon the stripping signals at the bismuth-coated sensor are explored. The square-wave peak current signal is linear over the low ng mL(-1) range (120 s deposition), with detections limits ranging from 0.9 to 4.9 ng mL(-1) and good precision. Applicability to waste water certified reference material and drinking water samples is demonstrated. The attractive behaviour of the new disposable Bi nanoparticles modified carbon strip electrodes, coupled with the negligible toxicity of bismuth, hold great promise for decentralized heavy metal testing in environmental and industrial effluents waters.

  12. Green syntheses, v.1

    CERN Document Server

    Tundo, Pietro

    2014-01-01

    Introduction to the Green Syntheses SeriesPietro Tundo and John AndraosApplication of Material Efficiency Metrics to Assess Reaction Greenness-Illustrative Case Studies from Organic SynthesesJohn AndraosReaction 1: Synthesis of 3-Benzyl-5-Methyleneoxazolidin-2-one from N-Benzylprop-2-yn-1-Amine and CO2Qing-Wen Song and Liang-Nian HeReaction 2: Synthesis of the 5-Membered Cyclic Carbonates from Epoxides and CO2Qing-Wen Song, Liang-Nian HePart I: Green Methods for the Epoxidation of

  13. Shape dependent heat transport through green synthesized gold nanofluids

    Science.gov (United States)

    John, Jisha; Thomas, Lincy; Kumar, B. Rajesh; Kurian, Achamma; George, Sajan D.

    2015-08-01

    Nanofluids hold promise as a more efficient coolant for thermoelectric devices. Despite the capability of tailoring the thermo physical properties of nanofluids, by tuning the particle parameters such as shape, size and concentration, the toxicity of chemicals used for the preparation of nanoparticles is a serious concern. Green synthesis of nanoparticles is emerging as an alternative to the conventional chemical and physical methods for the preparation of nanoparticles. In this work, the results of the preparation of gold nanoparticles using plant extracts as reducing agents are presented. The green synthesis route employed for the present study provides particles of similar size, but the shape of the particles is found to vary depending upon the source of the natural reducing agents. The thermal diffusivity values of the gold nanofluid measured using laser based dual beam thermal lens technique elucidate the role of shape and concentration of the green synthesized nanoparticles on the effective thermal diffusivity values of the nanofluids.

  14. Tannin biosynthesis of iron oxide nanoparticles

    Science.gov (United States)

    Herrera-Becerra, R.; Rius, J. L.; Zorrilla, C.

    2010-08-01

    In this work, iron oxide nanoparticles synthesized with gallic acid and tannic acid are characterized using High-Resolution Transmission Electron Microscopy (HRTEM). Its size, form, and structure are compared with nanoparticles obtained previously using alfalfa biomass in order to find a simpler, consistent, and environmentally friendly method in the production of iron oxide nanoparticles.

  15. Nanotoxicology of Metal Oxide Nanoparticles

    OpenAIRE

    Amedea B. Seabra; Nelson Durán

    2015-01-01

    This review discusses recent advances in the synthesis, characterization and toxicity of metal oxide nanoparticles obtained mainly through biogenic (green) processes. The in vitro and in vivo toxicities of these oxides are discussed including a consideration of the factors important for safe use of these nanomaterials. The toxicities of different metal oxide nanoparticles are compared. The importance of biogenic synthesized metal oxide nanoparticles has been increasing in recent years; howeve...

  16. Coalescence Behavior of Gold Nanoparticles

    OpenAIRE

    Wang YQ; Liang WS; Geng CY

    2009-01-01

    Abstract The tetraoctylammonium bromide (TOAB)-stabilized gold nanoparticles have been successfully fabricated. After an annealing of the as-synthesized nanoparticles at 300 °C for 30 min, the coalescence behavior of gold nanoparticles has been investigated using high-resolution transmission electron microscopy in detail. Two types of coalescence, one being an ordered combination of two or more particles in appropriate orientations through twinning, and the other being an ordered combina...

  17. Polymer Protected Gold Nanoparticles

    OpenAIRE

    Shan, Jun

    2006-01-01

    Polymer protected gold nanoparticles have successfully been synthesized by both "grafting-from" and "grafting-to" techniques. The synthesis methods of the gold particles were systematically studied. Two chemically different homopolymers were used to protect gold particles: thermo-responsive poly(N-isopropylacrylamide), PNIPAM, and polystyrene, PS. Both polymers were synthesized by using a controlled/living radical polymerization process, reversible addition-fragmentation chain transfer (RAFT)...

  18. Radiolitically Synthesized Hybrid Nanosystems for Bio-Nano-Technologies

    International Nuclear Information System (INIS)

    In this report a review of the main results and the studies carried out under the scope of the IAEA CRP project: Nanoscale Radiation Engineering of Advanced Materials for Potential Biomedical Application is presented. In particular two topics are discussed: radiation synthesizing of Ag nanoparticles in hydrogels for potential biomedical application and decoration of carbon nanotubes with Ag clusters by gamma irradiation. (author)

  19. Methods of synthesizing thermoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhifeng; Chen, Shuo; Liu, Wei-Shu; Wang, Hengzhi; Wang, Hui; Yu, Bo; Chen, Gang

    2016-04-05

    Methods for synthesis of thermoelectric materials are disclosed. In some embodiments, a method of fabricating a thermoelectric material includes generating a plurality of nanoparticles from a starting material comprising one or more chalcogens and one or more transition metals; and consolidating the nanoparticles under elevated pressure and temperature, wherein the nanoparticles are heated and cooled at a controlled rate.

  20. SYNTHESIS OF COPPER NANOPARTICLES BY ASPERGILLUS SPECIES

    Directory of Open Access Journals (Sweden)

    Kantabathini Venkata Pavani

    2013-06-01

    Full Text Available Recent developments in the biosynthesis of nanomaterials have demonstrated the important role of microorganisms in nanotechnology. The organisms show a unique potential in environmentally friendly production and accumulation of nanoparticles with different shapes and sizes. The present study proposed a green process for synthesis of copper nanoparticles using Aspergillus species. Syntheses of copper nanoparticles were characterized by UV-visible spectroscopy. The extracellular synthesis of copper nanoparticles was characterized by scanning electron microscopy and Transmission electron microscopy.

  1. Newly synthesized salicylidene-4,4′-dimorpholine (SDM) assembled on nickel oxide nanoparticles (NiONPs) and its inhibitive effect on mild steel in 2 N hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Wadhwani, Poonam M. [Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat (India); Panchal, Vikram K., E-mail: vikram60panchal@gmail.com [R.G. Shah Science College, Vasna, Ahmedabad 382170, Gujarat (India); Shah, Nisha K. [Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat (India)

    2015-03-15

    Graphical abstract: - Highlights: • Nanoparticles with inhibitor were found to be better corrosion inhibitor than only organic compound. • A strong binding mechanism was confirmed by FTIR, PXRD. • Inhibition efficiency increases drastically for SDM assembled on NiONPs as compared to SDM. • The adsorption model obeys Langmuir adsorption isotherm. • The protective layer over the surface of mild steel has been confirmed by AFM analysis. - Abstract: Corrosion inhibition of mild steel in hydrochloric acid solution by salicylidene-4,4′-dimorpholine (SDM) and SDM assembled on nickel oxide nanoparticles (NiONPs) has been studied with gravimetric, electrochemical impedance spectroscopy (EIS) and polarization techniques. Inhibition was found to increase with increasing concentration of the inhibitors. While studying the temperature effect on corrosion behaviour of SDM and SDM assembled on NiONPs, the inhibition efficiency decreases for SDM only but increases for SDM assembled on NiONPs. The adsorption of both the inhibitors on the mild steel surface obeys the Langmuir adsorption isotherm. The activation energy as well as other thermodynamic parameters (ΔH* and ΔS*) for the inhibition process was calculated. EIS analysis results showed that the capacitive loops for SDM assembled on NiONPs were far away from blank when compared with SDM only. Polarization curve shows that the inhibitors are of mixed type. Further, the protective layer formation was confirmed from atomic force microscopy (AFM) results. Various methods such as EIS-MS, {sup 1}H NMR, XRD, FTIR, and DLS were performed for the confirmation of the structure, interaction of SDM with NiONPs and size of NiONPs.

  2. Programmable electronic synthesized capacitance

    Science.gov (United States)

    Kleinberg, Leonard L. (Inventor)

    1987-01-01

    A predetermined and variable synthesized capacitance which may be incorporated into the resonant portion of an electronic oscillator for the purpose of tuning the oscillator comprises a programmable operational amplifier circuit. The operational amplifier circuit has its output connected to its inverting input, in a follower configuration, by a network which is low impedance at the operational frequency of the circuit. The output of the operational amplifier is also connected to the noninverting input by a capacitor. The noninverting input appears as a synthesized capacitance which may be varied with a variation in gain-bandwidth product of the operational amplifier circuit. The gain-bandwidth product may, in turn, be varied with a variation in input set current with a digital to analog converter whose output is varied with a command word. The output impedance of the circuit may also be varied by the output set current. This circuit may provide very small ranges in oscillator frequency with relatively large control voltages unaffected by noise.

  3. Solventless synthesis of ruthenium nanoparticles

    Science.gov (United States)

    García-Peña, Nidia G.; Redón, Rocío; Herrera-Gomez, Alberto; Fernández-Osorio, Ana Leticia; Bravo-Sanchez, Mariela; Gomez-Sosa, Gustavo

    2015-06-01

    This paper presents a novel solventless method for the synthesis of zero-valent ruthenium nanoparticles Ru(0). The proposed method, although not entirely new in the nanomaterials world, was used for the first time to synthesize zero-valent ruthenium nanoparticles. This new approach has proved to be an environmentally friendly, clean, cheap, fast, and reproducible technique which employs low amounts of solvent. It was optimized through varying amounts of reducing salt on a determined quantity of precursor and measuring the effect of this variation on the average particle size obtained. The resulting products were fully characterized by powder XRD, TEM, HR-TEM, and XPS studies, all of which corroborated the purity of the nanoparticles achieved. In order to verify the advantages of our method over other techniques, we compared our nanoparticles with two common colloidal-synthesized ruthenium nanoparticles.

  4. Polyol-synthesized Zn{sub 0.9}Mn{sub 0.1}S nanoparticles as potential luminescent and magnetic bimodal imaging probes: synthesis, characterization, and toxicity study

    Energy Technology Data Exchange (ETDEWEB)

    Gaceur, M.; Giraud, M., E-mail: marion.giraud@univ-paris-diderot.fr; Hemadi, M.; Nowak, S. [ITODYS, Universite Paris Diderot, Sorbonne Paris Cite (France); Menguy, N. [IMPMC, Universite Pierre et Marie Curie (France); Quisefit, J. P. [LISA, Universite Paris Diderot, Universite Paris Est Creteil (France); David, K. [Universite de Cergy-Pontoise, ERRMECe EA1391, Institut des Materiaux (France); Jahanbin, T.; Benderbous, S. [INSERM U-825, Pavillon Baudot (France); Boissiere, M. [Universite de Cergy-Pontoise, ERRMECe EA1391, Institut des Materiaux (France); Ammar, S., E-mail: ammarmer@univ-paris-diderot.fr [ITODYS, Universite Paris Diderot, Sorbonne Paris Cite (France)

    2012-07-15

    We report here the synthesis, by the polyol method, of Mn-doped ZnS nanocrystals with the zinc blende structure. Phase transfer of the as-produced quantum dots from organic solvent into water was achieved by surface complexation with mercaptoacetate ligands. The magnetic and optical properties of the powders and aqueous colloids obtained were evaluated by SQUID magnetometry as well as electronic absorption and emission spectroscopies, to test their potential as magnetic and luminescent bimodal probes for medical imaging. With a 10 % concentration of Mn{sup 2+}, the nanoparticles are paramagnetic at body temperature, and the aqueous colloids they form have high relaxivity with a r{sub 1} value of 20 mM{sup -1} s{sup -1} at 3 T. They are highly luminescent with a blue-green emission on 405-nm excitation. Viability assays and genotoxicity tests on Chinese hamster ovarian cells revealed neither acute cellular death, nor cell toxicity, nor damage to the nucleus after exposure for 24 h to particle doses of up to 100 {mu}g mL{sup -1}.

  5. Solvent resistant microfluidic DNA synthesizer.

    Science.gov (United States)

    Huang, Yanyi; Castrataro, Piero; Lee, Cheng-Chung; Quake, Stephen R

    2007-01-01

    We fabricated a microfluidic DNA synthesizer out of perfluoropolyether (PFPE), an elastomer with excellent chemical compatibility which makes it possible to perform organic chemical reactions, and synthesized 20-mer oligonucleotides on chip. PMID:17180201

  6. Microwave assisted template synthesis of silver nanoparticles

    Indian Academy of Sciences (India)

    K J Sreeram; M Nidhin; B U Nair

    2008-12-01

    Easier, less time consuming, green processes, which yield silver nanoparticles of uniform size, shape and morphology are of interest. Various methods for synthesis, such as conventional temperature assisted process, controlled reaction at elevated temperatures, and microwave assisted process have been evaluated for the kind of silver nanoparticles synthesized. Starch has been employed as a template and reducing agent. Electron microscopy, photon correlation spectroscopy and surface plasmon resonance have been employed to characterize the silver nanoparticles synthesized. Compared to conventional methods, microwave assisted synthesis was faster and provided particles with an average particle size of 12 nm. Further, the starch functions as template, preventing the aggregation of silver nanoparticles.

  7. Comparative assessment of the apoptotic potential of silver nanoparticles synthesized by Bacillus tequilensis and Calocybe indica in MDA-MB-231 human breast cancer cells: targeting p53 for anticancer therapy

    Directory of Open Access Journals (Sweden)

    Gurunathan S

    2015-06-01

    Full Text Available Sangiliyandi Gurunathan, Jung Hyun Park, Jae Woong Han, Jin-Hoi KimDepartment of Animal Biotechnology, Konkuk University, Seoul, Republic of KoreaBackground: Recently, the use of nanotechnology has been expanding very rapidly in diverse areas of research, such as consumer products, energy, materials, and medicine. This is especially true in the area of nanomedicine, due to physicochemical properties, such as mechanical, chemical, magnetic, optical, and electrical properties, compared with bulk materials. The first goal of this study was to produce silver nanoparticles (AgNPs using two different biological resources as reducing agents, Bacillus tequilensis and Calocybe indica. The second goal was to investigate the apoptotic potential of the as-prepared AgNPs in breast cancer cells. The final goal was to investigate the role of p53 in the cellular response elicited by AgNPs.Methods: The synthesis and characterization of AgNPs were assessed by various analytical techniques, including ultraviolet-visible (UV-vis spectroscopy, X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, dynamic light scattering (DLS, and transmission electron microscopy (TEM. The apoptotic efficiency of AgNPs was confirmed using a series of assays, including cell viability, leakage of lactate dehydrogenase (LDH, production of reactive oxygen species (ROS, DNA fragmentation, mitochondrial membrane potential, and Western blot.Results: The absorption spectrum of the yellow AgNPs showed the presence of nanoparticles. XRD and FTIR spectroscopy results confirmed the crystal structure and biomolecules involved in the synthesis of AgNPs. The AgNPs derived from bacteria and fungi showed distinguishable shapes, with an average size of 20 nm. Cell viability assays suggested a dose-dependent toxic effect of AgNPs, which was confirmed by leakage of LDH, activation of ROS, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL-positive cells in MDA

  8. Synthesis of silver nanoparticles and antibacterial property of silk fabrics treated by silver nanoparticles

    OpenAIRE

    ZHANG, GUANGYU; Liu, Yan; Gao, Xiaoliang; Chen, Yuyue

    2014-01-01

    A silver nanoparticle solution was prepared in one step by mixing AgNO3 and a multi-amino compound (RSD-NH2) solution under ambient condition. RSD-NH2 was in-house synthesized by methacrylate and polyethylene polyamine in methanol, which has abundant amino and imino groups. However, the characterization of silver nanoparticles indicated that these nanoparticles are easy to agglomerate in solution. Therefore, an in situ synthesis method of silver nanoparticles on the silk fabrics was developed...

  9. Doclet To Synthesize UML

    Science.gov (United States)

    Barry, Matthew R.; Osborne, Richard N.

    2005-01-01

    The RoseDoclet computer program extends the capability of Java doclet software to automatically synthesize Unified Modeling Language (UML) content from Java language source code. [Doclets are Java-language programs that use the doclet application programming interface (API) to specify the content and format of the output of Javadoc. Javadoc is a program, originally designed to generate API documentation from Java source code, now also useful as an extensible engine for processing Java source code.] RoseDoclet takes advantage of Javadoc comments and tags already in the source code to produce a UML model of that code. RoseDoclet applies the doclet API to create a doclet passed to Javadoc. The Javadoc engine applies the doclet to the source code, emitting the output format specified by the doclet. RoseDoclet emits a Rose model file and populates it with fully documented packages, classes, methods, variables, and class diagrams identified in the source code. The way in which UML models are generated can be controlled by use of new Javadoc comment tags that RoseDoclet provides. The advantage of using RoseDoclet is that Javadoc documentation becomes leveraged for two purposes: documenting the as-built API and keeping the design documentation up to date.

  10. Structure and magnetic properties of Zr–Mn substituted strontium hexaferrite Sr(Zr,Mn)$_x$Fe$_{12−2x}$O$_{19}$ nanoparticles synthesized by sol–gel auto-combustion method

    Indian Academy of Sciences (India)

    S ALAMOLHODA; S M MIRKAZEMI; Z GHIAMI; M NIYAIFAR

    2016-09-01

    In this research, nano-sized powders of Zr–Mn substituted strontium hexaferrite (Sr(Zr,Mn)$_x$Fe$_{12−2x}$O$_{19}$ ($x = 0, 2, 2.5, 3$)) were synthesized by sol–gel auto-combustion route using subsequent heat treatment. The samples were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), Mössbauer spectroscopyand vibration sample magnetometer (VSM) techniques. XRD and Mössbauer spectroscopy results revealed formation of Sr(Zr,Mn)$_x$Fe$_{12−2x}$O$_{19}$ accompanied with Mn$_{\\delta}$Fe$_{2−\\delta}$O$_4$ lateral phase in the samples. Also, FTIR and XRDresults demonstrated presence of SrO impurity phase. FESEM micrographs show particle size reduction and presence of two distinct powder morphologies with different brightness levels with Zr$^{4+}$ and Mn$^{2+}$ substitutions which approves existence of lateral phases in the substituted samples. TEM micrographs show nanometric particles with sizes smaller than 100nm with high crystallinity. Mössbauer results showed that at low level of substitution, Zr$^{4+}$ ions prefer to occupy both 4f1 and 2b however, at higher level of substitution, they prefer exclusively 4f1 site. While, Mn$^{2+}$ ions distributed approximately equally between 12k and 2a sites. The presence of nonmagnetic Zr$^{4+}$ cation leads to decrease in exchange interaction, especially at 12k and 2a sites. VSM results showed decrement of coercivity force (${}_i$H$_c$) from 5593.60 to 3282.46 Oe and maximum magnetization from 62.60 to 46.15 emu g$^{−1}$, respectively, by increment of Zr–Mn substitution values. Variations in maximum magnetization magnitude have been explained on the basis of occupation of the substituted cations at different iron sites.

  11. Fabrication of transparent ceramics using nanoparticles

    Science.gov (United States)

    Cherepy, Nerine J; Tillotson, Thomas M; Kuntz, Joshua D; Payne, Stephen A

    2012-09-18

    A method of fabrication of a transparent ceramic using nanoparticles synthesized via organic acid complexation-combustion includes providing metal salts, dissolving said metal salts to produce an aqueous salt solution, adding an organic chelating agent to produce a complexed-metal sol, heating said complexed-metal sol to produce a gel, drying said gel to produce a powder, combusting said powder to produce nano-particles, calcining said nano-particles to produce oxide nano-particles, forming said oxide nano-particles into a green body, and sintering said green body to produce the transparent ceramic.

  12. Mycosynthesis of silver nanoparticles bearing antibacterial activity.

    Science.gov (United States)

    Azmath, Pasha; Baker, Syed; Rakshith, Devaraju; Satish, Sreedharamurthy

    2016-03-01

    Mycosynthesis of silver nanoparticles was achieved by endophytic Colletotrichum sp. ALF2-6 inhabiting Andrographis paniculata. Well dispersed nanoparticles were characterized using UV-Visible spectrometry with maximum absorption conferring at 420 nm. FTIR analysis revealed possible biomolecules reducing the metal salt and stabilization of nanoparticles. XRD analysis depicted the diffraction intensities exhibiting between 20 and 80 °C at 2theta angle thus conferring the crystalline nature of nanoparticles. Morphological characteristic using TEM revealed the polydispersity of nanoparticles with size ranging from 20 to 50 nm. Synthesized nanoparticles exhibited bactericidal activity against selected human pathogens. Nanoparticles mode of action was carried out to reveal DNA damage activity. Thus the present investigation reports facile fabrication of silver nanoparticles from endophytic fungi. PMID:27013906

  13. Zinc nanoparticles in solution by laser ablation technique

    Indian Academy of Sciences (India)

    S C Singh; R Gopal

    2007-06-01

    Colloidal zinc metallic nanoparticles are synthesized using pulsed laser ablation of metal plate in an aqueous solution of suitable surfactant to prevent aggregation. UV-visible absorption, TEM, small angle X-ray diffraction and wide-angle X-ray diffraction are used for the characterization of colloidal zinc metallic nanoparticles. Colloidal nanoparticles are found highly stable for a long time.

  14. Study of streptavidin coated onto PAMAM dendrimer modified magnetite nanoparticles

    International Nuclear Information System (INIS)

    Polyamidoamine dendrimer was synthesized on the surface of amino silane modified magnetite nanoparticles. After coating of streptavidin to these dendrimer-modified magnetite nanoparticles, an up to 3.4 times higher amount of streptavidin (SA) was measured compared to magnetite nanoparticles modified with only amino silane. The biotin-binding capacity of SA thus increased after dendrimer modification

  15. Size Controlled Synthesis of Starch Nanoparticles by a Microemulsion Method

    Directory of Open Access Journals (Sweden)

    Suk Fun Chin

    2014-01-01

    Full Text Available Controllable particles sizes of starch nanoparticles were synthesized via a precipitation in water-in-oil microemulsion approach. Microemulsion method offers the advantages of ultralow interfacial tension, large interfacial area, and being thermodynamically stable and affords monodispersed nanoparticles. The synthesis parameters such as stirring rates, ratios of oil/cosurfactant, oil phases, cosurfactants, and ratios of water/oil were found to affect the mean particle size of starch nanoparticles. Starch nanoparticles with mean particles sizes of 109 nm were synthesized by direct nanoprecipitation method, whereas by using precipitation in microemulsion approach, starch nanoparticles with smaller mean particles sizes of 83 nm were obtained.

  16. Radiation-induced synthesis of gold, iron-oxide composite nanoparticles

    International Nuclear Information System (INIS)

    Composite nanoparticles consisting of magnetic iron oxide nanoparticles and gold nanoparticles were synthesized using gamma-rays or electron beam. Ionizing irradiation induces the generation of reducing species inside the aqueous solution, and gold ions are reduced to form metallic Au nanoparticles. The size of Au nanoparticles depended on the dose rate and the concentration of support iron oxide. The gold nanoparticles on iron oxide nanoparticles selectively adsorb biomolecules via Au-S bonding. By using magnetic property of the support iron oxide nanoparticles, the composite nanoparticles are expected as a new type of magnetic nanocarrier for biomedical applications. (author)

  17. Biotinylated magnetic nanoparticles for pretargeting: synthesis and characterization study

    OpenAIRE

    Chauhan, Ram Prakash; Singh, Gurjaspreet; Singh, Sweta; Bag, Narmada; Patra, Manoj; S. R. Vadera; Mishra, Anil K.; Mathur, Rashi

    2011-01-01

    In this paper, we have proposed a simple method to covalently conjugate biotin to magnetic nanoparticles, which can be targeted to the tumour sites by using pretargeting approach with avidin or streptavidin. Magnetic nanoparticles of manganese ferrite were synthesized by alkaline coprecipitation of ferric chloride hexahydrate, ferrous sulphate heptahydrate and manganese sulphate monohydrate using ammonium hydroxide. The synthesized magnetic nanoparticles were then successfully surface modifie...

  18. Synthesis and Characterization of Gold Nanoparticles

    OpenAIRE

    Hedkvist, Olof

    2013-01-01

    This thesis is focused on the synthesis of three different shapes of gold nanoparticles; the gold nanosphere, the gold nanorod and the gold nanocube. These will be synthesized using wet chemistry methods and characterized using UV-Vis- NIR spectroscopy and dynamic light scattering. The results will be used to draw some conclusions as to what factors influence the growth of gold nanoparticles.

  19. Green Nanoparticles for Mosquito Control

    Science.gov (United States)

    Soni, Namita; Prakash, Soam

    2014-01-01

    Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag) and gold (Au) nanoparticles (NPs) were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum) (C. zyelanicum or C. verum J. Presl). Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM). The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77 nm AgNPs and 46.48 nm AuNPs). The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito. PMID:25243210

  20. Green Nanoparticles for Mosquito Control

    Directory of Open Access Journals (Sweden)

    Namita Soni

    2014-01-01

    Full Text Available Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag and gold (Au nanoparticles (NPs were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum (C. zyelanicum or C. verum J. Presl. Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM. The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77 nm AgNPs and 46.48 nm AuNPs. The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito.

  1. SYNTHESIS OF COPPER NANOPARTICLES BY ASPERGILLUS SPECIES

    OpenAIRE

    Kantabathini Venkata Pavani; Nandigam Srujana; Guntur Preethi; Tandale Swati

    2013-01-01

    Recent developments in the biosynthesis of nanomaterials have demonstrated the important role of microorganisms in nanotechnology. The organisms show a unique potential in environmentally friendly production and accumulation of nanoparticles with different shapes and sizes. The present study proposed a green process for synthesis of copper nanoparticles using Aspergillus species. Syntheses of copper nanoparticles were characterized by UV-visible spectroscopy. The extracellular synthesis of co...

  2. Coalescence Behavior of Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Wang YQ

    2009-01-01

    Full Text Available Abstract The tetraoctylammonium bromide (TOAB-stabilized gold nanoparticles have been successfully fabricated. After an annealing of the as-synthesized nanoparticles at 300 °C for 30 min, the coalescence behavior of gold nanoparticles has been investigated using high-resolution transmission electron microscopy in detail. Two types of coalescence, one being an ordered combination of two or more particles in appropriate orientations through twinning, and the other being an ordered combination of two small particles with facets through a common lattice plane, have been observed.

  3. Nanotoxicology of Metal Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Amedea B. Seabra

    2015-06-01

    Full Text Available This review discusses recent advances in the synthesis, characterization and toxicity of metal oxide nanoparticles obtained mainly through biogenic (green processes. The in vitro and in vivo toxicities of these oxides are discussed including a consideration of the factors important for safe use of these nanomaterials. The toxicities of different metal oxide nano