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Sample records for nanocomposite facile synthesis

  1. Facile solvothermal synthesis of graphene-MnOOH nanocomposites

    International Nuclear Information System (INIS)

    Chen Sheng; Zhu Junwu; Huang Huajie; Zeng Guiyu; Nie Fude; Wang Xin

    2010-01-01

    In this paper, we report a facile solvothermal route capable of aligning MnOOH nanocrystals on graphene. X-ray diffraction (XRD) and transmission electron microscopy (TEM) observations indicate that the exfoliated graphene sheets are decorated randomly by MnOOH nanocrystals, forming well-dispersed graphene-MnOOH nanocomposites. Dissolution-crystallization and oriented attachment are speculated to be the vital mechanisms in the synthetic process. The attachment of additives, such as MnOOH nanoparticles, are found to be beneficial for the exfoliation of GO as well as preventing the restack of graphene sheets. Moreover, cyclic voltammetry (CV) analyses suggest that the electrochemical reversibility is improved by anchoring MnOOH on graphene. Notably, the as-fabricated nanocomposites reveal unusual catalytic performance for the thermal decomposition of ammonium perchlorate (AP) due to the concerted effects of graphene and MnOOH. This template-free method is easy to reproduce, and the process proceeds at a low temperature and can be readily extended to prepare other graphene-based nanocomposites. - Graphical abstract: Manganese oxyhydroxide nanocrystals have been successfully attached onto the graphene sheets via an oriented attachment and dissolution-crystallization process, forming a nanocomposite with unusual catalytic capabilities. Display Omitted

  2. Facile synthesis of carbon-ZnO nanocomposite with enhanced visible light photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Akir, Sana [Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520 − IEMN, F-59000, Centrale Lille (France); Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021, Bizerte (Tunisia); Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopôle de Bordj Cedria, BP73, 8027, Soliman (Tunisia); Hamdi, Abderrahmane [Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520 − IEMN, F-59000, Centrale Lille (France); Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021, Bizerte (Tunisia); Laboratory of Semi-conductors, Nano-structures and Advanced Technologies, Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050, Hammam-Lif (Tunisia); Addad, Ahmed [UMET, UMR CNRS 8207, Université Lille 1, 59655 Villeneuve d' Ascq Cédex (France); Coffinier, Yannick [Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520 − IEMN, F-59000, Centrale Lille (France); Boukherroub, Rabah, E-mail: rabah.boukherroub@iemn.univ-lille1.fr [Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520 − IEMN, F-59000, Centrale Lille (France); and others

    2017-04-01

    Highlights: • C-ZnO nanocomposite was successfully prepared via a facile and eco-friendly process. • C-ZnO NPs have excellent photocatalytic activity for RhB dye degradation under visible light irradiation compared with literature. • The visible photocatalytic properties originate from injection e{sup −} in CB of ZnO from RhB. - Abstract: The present study describes a facile route for synthesis of carbon-ZnO nanocomposites (C-ZnO) via hydrothermal process in presence of glucose as carbon precursor. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) measurements. The results showed carbon uniformly coated on the surface of the ZnO nanoparticles to form the C-ZnO nanocomposites. Further investigation revealed that carbon could significantly protect ZnO NPs against the coalescence during high temperature treatment. The obtained C-ZnO nanocomposite showed excellent photocatalytic activity for the degradation of rhodamine B (RhB) under visible light irradiation, which was attributed to the repressed charge carrier recombination in the nanocomposite. Quenching experiments and photocurrent measurements revealed a photocatalytic mechanism occurring through photosensitization.

  3. Facile synthesis, dielectric properties and electrocatalytic activities of PMMA-NiFe2O4 nanocomposite

    International Nuclear Information System (INIS)

    Maji, Pranabi; Choudhary, Ram Bilash

    2017-01-01

    The paper deals with the dielectric and catalytic properties of poly (methyl methacrylate)-nikel ferrite (PMMA-NiFe 2 O 4 ) nanocomposite. The nanocomposite was prepared by using a general and facile synthesis strategy. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectra confirmed the formation of PMMA-NiFe 2 O 4 nanocomposite. Field effect scanning electron microscopic (FESEM) and transmission electron microscopic (TEM) images revealed that NiFe 2 O 4 nanoparticles were uniformly distributed and were tightly adhered with PMMA matrix owing to surface modification with 3-methacryloyloxy propyl trimethoxy silane (KH-570). Thermal stability was enhanced by incorporation of NiFe 2 O 4 nanofillers. The nanocomposite showed high dielectric constant and low dielectric loss. The achieved dielectric and thermal property inferred the potential application of this material in energy storage and embedded electronics devices. Further, the as prepared nanocomposite also offered a remarkable electrochemical performance towards hydrogen peroxide (H 2 O 2 ) sensing. - Highlights: • PMMA-NiFe 2 O 4 nanocomposite was synthesized via free radical polymerization. • The nanocomposite exhibited high value of dielectric constant (51) and tanδ (0.3). • Thermal stability of the PMMA matrix was improved by the incorporation of NiFe 2 O 4. • The H 2 O 2 detection limit was estimated 44 μM when signal to noise (S/N) ration was 3. • The electrochemical sensitivity of H 2 O 2 was calculated 0.6727 μA mM -1 .

  4. Facile synthesis of TiO2/microcrystalline cellulose nanocomposites: photocatalytically active material under visible light irradiation

    Science.gov (United States)

    Doped TiO2 nanocomposites were prepared in situ by a facile and simple synthesis utilizing benign and renewable precursors such as microcrystalline cellulose (MC) and TiCl4 through hydrolysis in alkaline medium without the addition of organic solvents. The as-prepared nanocompos...

  5. Facile synthesis of a silver nanoparticles/polypyrrole nanocomposite for non-enzymatic glucose determination.

    Science.gov (United States)

    Poletti Papi, Maurício A; Caetano, Fabio R; Bergamini, Márcio F; Marcolino-Junior, Luiz H

    2017-06-01

    The present work describes the synthesis of a new conductive nanocomposite based on polypyrrole (PPy) and silver nanoparticles (PPy-AgNP) based on a facile reverse microemulsion method and its application as a non-enzymatic electrochemical sensor for glucose detection. Focusing on the best sensor performance, all experimental parameters used in the synthesis of nanocomposite were optimized based on its electrochemical response for glucose. Characterization of the optimized material by FT-IR, cyclic voltammetry, and DRX measurements and TEM images showed good monodispersion of semispherical Ag nanoparticles capped by PPy structure, with size average of 12±5nm. Under the best analytical conditions, the proposed sensor exhibited glucose response in linear dynamic range of 25 to 2500μmolL -1 , with limit of detection of 3.6μmolL -1 . Recovery studies with human saliva samples varying from 99 to 105% revealed the accuracy and feasibility of a non-enzymatic electrochemical sensor for glucose determination by easy construction and low-cost. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Facile Synthesis of Au Nanocube-CdS Core-Shell Nanocomposites with Enhanced Photocatalytic Activity

    Science.gov (United States)

    Liu, Xiao-Li; Liang, Shan; Li, Min; Yu, Xue-Feng; Zhou, Li; Wang, Qu-Qua

    2014-06-01

    Au nanocube-CdS core-shell nanocomposites are prepared by using a one-pot method in aqueous phase with cetyltrimethylammonium bromide as the surfactant. The extinction properties and photocatalytic activity of Au-CdS nanocomposites are investigated. Compared with the pure Au nanocubes, the Au-CdS nanocomposites exhibit enhanced extinction intensity. Compared with CdS nanoparticles, the Au-CdS nanocomposites exhibit improved photocatalytic activity. Furthermore, the photocatalytic efficiency is even better with the increase in the core size of the Au-CdS nanocomposites. Typically, the photocatalytic efficiency of the Au-CdS with 62 nm sized Au nanocubes is about two times higher than that of the pure CdS. It is believed that the Au-CdS nanocomposites may find potential applications in environmental fields, and this synthesis method can be extended to prepare a wide variety of functional composites with Au cores.

  7. Facile synthesis, dielectric properties and electrocatalytic activities of PMMA-NiFe{sub 2}O{sub 4} nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Maji, Pranabi; Choudhary, Ram Bilash, E-mail: rbcism@gmail.com

    2017-06-01

    The paper deals with the dielectric and catalytic properties of poly (methyl methacrylate)-nikel ferrite (PMMA-NiFe{sub 2}O{sub 4}) nanocomposite. The nanocomposite was prepared by using a general and facile synthesis strategy. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectra confirmed the formation of PMMA-NiFe{sub 2}O{sub 4} nanocomposite. Field effect scanning electron microscopic (FESEM) and transmission electron microscopic (TEM) images revealed that NiFe{sub 2}O{sub 4} nanoparticles were uniformly distributed and were tightly adhered with PMMA matrix owing to surface modification with 3-methacryloyloxy propyl trimethoxy silane (KH-570). Thermal stability was enhanced by incorporation of NiFe{sub 2}O{sub 4} nanofillers. The nanocomposite showed high dielectric constant and low dielectric loss. The achieved dielectric and thermal property inferred the potential application of this material in energy storage and embedded electronics devices. Further, the as prepared nanocomposite also offered a remarkable electrochemical performance towards hydrogen peroxide (H{sub 2}O{sub 2}) sensing. - Highlights: • PMMA-NiFe{sub 2}O{sub 4} nanocomposite was synthesized via free radical polymerization. • The nanocomposite exhibited high value of dielectric constant (51) and tanδ (0.3). • Thermal stability of the PMMA matrix was improved by the incorporation of NiFe{sub 2}O{sub 4.} • The H{sub 2}O{sub 2} detection limit was estimated 44 μM when signal to noise (S/N) ration was 3. • The electrochemical sensitivity of H{sub 2}O{sub 2} was calculated 0.6727 μA mM{sup -1}.

  8. Facile synthesis of reduced graphene oxide/CoWO4 nanocomposites with enhanced electrochemical performances for supercapacitors

    International Nuclear Information System (INIS)

    Xu, Xiaowei; Shen, Jianfeng; Li, Na; Ye, Mingxin

    2014-01-01

    Highlights: • RGO/CoWO 4 composites were successfully prepared through a facile hydrothermal method. • RGO/CoWO 4 composites show much higher specific capacitances than pure CoWO 4 . • Enhanced electrical conductivity leads to superior electrochemical performance. - Abstract: A facile one-pot hydrothermal method was provided for synthesis of the reduced graphene oxide-cobalt tungstate (RGO/CoWO 4 ) nanocomposites with the enhanced electrochemical performances for supercapacitors for the first time. The resulting nanocomposites are comprised of CoWO 4 nanospheres that are well-anchored on graphene sheets by in situ reducing. The prepared RGO/CoWO 4 nanocomposites have been thoroughly characterized by Fourier–transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, Thermogravimetric analysis, Scanning electron microscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy, and N 2 adsorption–desorption. Importantly, the prepared nanocomposites exhibit superior electrochemical performance to CoWO 4 as electrodes for supercapacitors. As a result, RGO/CoWO 4 nanocomposites with 91.6 wt% CoWO 4 content achieved a specific capacitance about 159.9 F g −1 calculated from the CV curves at 5 mV s −1 , which was higher than that of CoWO 4 (60.6 F g −1 ). The good electrochemical performance can be attributed to the increased electrical conductivity and the creation of new active sites due to the synergetic effect of RGO and CoWO 4 nanospheres. The cyclic stability tests demonstrated capacitance retention of about 94.7% after 1000 cycles, suggesting the potential application of RGO/CoWO 4 nanocomposites in energy-storage devices

  9. Facile synthesis of cobalt hexacyanoferrate/graphene nanocomposites for high-performance supercapacitor

    International Nuclear Information System (INIS)

    Wang, Jian-Gan; Zhang, Zhiyong; Liu, Xingrui; Wei, Bingqing

    2017-01-01

    Prussian blue and its analogues are promising for energy storage devices owing to the rigid open framework, yet suffer from poor conductivity and relatively low energy density. Herein, we report a facile preparation of cobalt hexacyanoferrate/reduced graphene oxide nanocomposites (CoHCF/rGO) for supercapacitors with enhanced performance. The CoHCF nanoparticles with a size of around 50 nm are adhered onto the rGO nanosheets, which, in turn, not only prevent the agglomeration of the CoHCF nanoparticles but also provide conductive network for fast electron transport. The CoHCF/rGO nanocomposite delivers a maximum specific capacitance of 361 F g"−"1 in Na_2SO_4 aqueous electrolyte. Asymmetric supercapacitor cells are assembled by pairing up an optimized nanocomposite electrode with an activated carbon negative electrode, which exhibits a wide reversible operating voltage of 2.0 V and a high energy density of 39.6 Wh kg"−"1. The enhanced electrochemical performance of CoHCF/rGO benefits from the strong synergistic utilization of CoHCF nanoparticles and rGO nanosheets, rendering the nanocomposites a great promise for high-performance supercapacitors.

  10. Facile synthesis of MnO{sub 2}/CNT nanocomposite and its electrochemical performance for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hongjuan, E-mail: cehjwang@scut.edu.cn [School of Chemistry and Chemcial Engineering, South China University of Technology, Guangzhou, 510640 (China); Peng Cheng [School of Chemistry and Chemcial Engineering, South China University of Technology, Guangzhou, 510640 (China); Peng Feng, E-mail: cefpeng@scut.edu.cn [School of Chemistry and Chemcial Engineering, South China University of Technology, Guangzhou, 510640 (China); Yu Hao; Yang Jian [School of Chemistry and Chemcial Engineering, South China University of Technology, Guangzhou, 510640 (China)

    2011-08-25

    Highlights: > MnO{sub 2}/CNTs are prepared by direct redox reaction between KMnO{sub 4} and carbon nanotubes. > This preparation method is a simple and green without any other additives. > MnO{sub 2}/CNTs show specific capacitance of 162.2 F g{sup -1} at the current density of 0.2 A g{sup -1}. > MnO{sub 2}/CNTs exhibit excellent charge-discharge property. - Abstract: A nanocomposite of manganese dioxide coated on the carbon nanotubes (MnO{sub 2}/CNTs) was synthesized by a facile direct redox reaction between potassium permanganate and carbon nanotubes without any other oxidant or reductant addition. The morphology, microstructure and crystalline form of this MnO{sub 2}/CNT nanocomposite were characterized by scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical properties are characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD). The results show that the facile prepared MnO{sub 2}/CNTs nanocomposite shows specific capacitance of 162.2 F g{sup -1} at the current density of 0.2 A g{sup -1} and excellent charge/discharge property with 90% of its specific capacitance kept after 2000 cycles at the current density of 5 A g{sup -1}.

  11. Facile synthesis of pristine graphene-palladium nanocomposites with extraordinary catalytic activities using swollen liquid crystals

    Science.gov (United States)

    Vats, T.; Dutt, S.; Kumar, R.; Siril, P. F.

    2016-09-01

    Amazing conductivity, perfect honeycomb sp2 arrangement and the high theoretical surface area make pristine graphene as one of the best materials suited for application as catalyst supports. Unfortunately, the low reactivity of the material makes the formation of nanocomposite with inorganic materials difficult. Here we report an easy approach to synthesize nanocomposites of pristine graphene with palladium (Pd-G) using swollen liquid crystals (SLCs) as a soft template. The SLC template gives the control to deposit very small Pd particles of uniform size on G as well as RGO. The synthesized nanocomposite (Pd-G) exhibited exceptionally better catalytic activity compared with Pd-RGO nanocomposite in the hydrogenation of nitrophenols and microwave assisted C-C coupling reactions. The catalytic activity of Pd-G nanocomposite during nitrophenol reduction reaction was sixteen times higher than Pd nanoparticles and more than double than Pd-RGO nanocomposite. The exceptionally high activity of pristine graphene supported catalysts in the organic reactions is explained on the basis of its better pi interacting property compared to partially reduced RGO. The Pd-G nanocomposite showed exceptional stability under the reaction conditions as it could be recycled upto a minimum of 15 cycles for the C-C coupling reactions without any loss in activity.

  12. Microwave assisted facile synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite and their application as active SERS substrate

    International Nuclear Information System (INIS)

    Wadhwa, Heena; Kumar, Devender; Mahendia, Suman; Kumar, Shyam

    2017-01-01

    The present paper represents the facile and rapid synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite with the help of microwave irradiation. The graphene oxide (GO) solution has been prepared in bulk using Hummer's method followed by microwave assisted in-situ reduction of GO and silver nitrate (AgNO_3) by hydrazine hydrate in a short spam of 5 min. The prepared nanocomposite has been characterized using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) Scanning Electron Microscopy (SEM) and UV–Visible spectroscopy. TEM analysis shows that Ag nanoparticles with average size 32 nm are uniformly entangled with in RGO layers. The UV–Visible absorption spectrum of nanocomposite depicts the reduction of GO to RGO along with the formation of Ag nanoparticles with the presence of characteristic surface Plasmon resonance (SPR) peak of Ag nanoparticles at 422 nm. The performance of prepared nanocomposite has been tested as the active Surface Enhanced Raman Scattering (SERS) substrate for Rhodamine 6G with detection limit 0.1 μM. - Highlights: • The RGO and RGO-Ag nanocomposite were synthesized with microwave irradiation. • Ag nanoparticles of average size 32 nm are uniformly entangled within RGO layers. • RGO itself is a florescence quencher with SERS detection limit 1 μM for R6G. • RGO-Ag nanocomposite show good SERS activity for R6G with detection limit 0.1 μM.

  13. Microwave assisted facile synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite and their application as active SERS substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wadhwa, Heena, E-mail: heenawadhwa1988@gmail.com; Kumar, Devender, E-mail: devkumsaroha@kuk.ac.in; Mahendia, Suman, E-mail: mahendia@gmail.com; Kumar, Shyam, E-mail: profshyam@gmail.com

    2017-06-15

    The present paper represents the facile and rapid synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite with the help of microwave irradiation. The graphene oxide (GO) solution has been prepared in bulk using Hummer's method followed by microwave assisted in-situ reduction of GO and silver nitrate (AgNO{sub 3}) by hydrazine hydrate in a short spam of 5 min. The prepared nanocomposite has been characterized using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) Scanning Electron Microscopy (SEM) and UV–Visible spectroscopy. TEM analysis shows that Ag nanoparticles with average size 32 nm are uniformly entangled with in RGO layers. The UV–Visible absorption spectrum of nanocomposite depicts the reduction of GO to RGO along with the formation of Ag nanoparticles with the presence of characteristic surface Plasmon resonance (SPR) peak of Ag nanoparticles at 422 nm. The performance of prepared nanocomposite has been tested as the active Surface Enhanced Raman Scattering (SERS) substrate for Rhodamine 6G with detection limit 0.1 μM. - Highlights: • The RGO and RGO-Ag nanocomposite were synthesized with microwave irradiation. • Ag nanoparticles of average size 32 nm are uniformly entangled within RGO layers. • RGO itself is a florescence quencher with SERS detection limit 1 μM for R6G. • RGO-Ag nanocomposite show good SERS activity for R6G with detection limit 0.1 μM.

  14. Facile synthesis of uniform MWCNT@Si nanocomposites as high-performance anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yifan; Du, Ning, E-mail: dna1122@zju.edu.cn; Zhang, Hui; Yang, Deren

    2015-02-15

    Highlights: • A uniform SiO{sub 2} layer was deposited on multi-walled carbon nanotube. • Synthesis of uniform (MWCNT)@Si nanocomposites via the magnesiothermic reduction. • The MWCNT@Si nanocomposites show high reversible capacity and good cyclability. • Enhanced performance is attributed to porous nanostructure, introduction of MWCNTs. - Abstract: We demonstrate the synthesis of uniform multi-walled carbon nanotube (MWCNT)@Si nanocomposites via the magnesiothermic reduction of pre-synthesized MWCNT@SiO{sub 2} nanocables. At first, the acid vapor steaming is used to treat the surface, which can facilitate the uniform deposition of SiO{sub 2} layer via the TEOS hydrolysis. Then, the uniform MWCNT@Si nanocomposites are obtained on the basis of MWCNT@SiO{sub 2} nanocables via a simple magnesiothermic reduction. When used as an anode material for lithium-ion batteries, the as-synthesized MWCNT@Si nanocomposites show high reversible capacity and good cycling performance, which is better than bulk Si and bare MWCNTs. It is believed that the good electrochemical performance can be attributed to the novel porous nanostructure and the introduction of MWCNTs that can buffer the volume change, maintain the electrical conductive network, and enhance the electronic conductivity and lithium-ion transport.

  15. Facile synthesis of carbon/MoO 3 nanocomposites as stable battery anodes

    KAUST Repository

    Ding, Jiang

    2017-03-09

    Pristine MoO3 is a potential anode material for lithium-ion batteries (LIBs), due to its high specific capacity (1117 mA h g−1); it suffers, however, from poor cyclability, resulting from a low conductivity and large volume changes during lithiation/delithiation process. Here we adopt a facile two-step method in which pristine bulk MoO3 is first converted into MoO3 nanorods (MoO3 NR) through mechanical grinding, to buffer the continuous volume changes, and then coated with amorphous carbon through simple stirring and heating, to provide high electronic and ionic conductivities. Electrochemical tests reveal that the carbon-coated MoO3 nanorods (C-MoO3 NRs) exhibit outstanding specific capacity (856 mA h g−1 after 110 cycles at a current density of 0.1 C); remarkable cycle life, among the best reported for carbon-based MoO3 nanostructures (485 mA h g−1 after 300 cycles at 0.5 C and 373 mA h g−1 after 400 cycles at 0.75 C); and greatly improved capacity retention (up to 90.4% after various C-rates) compared to bulk MoO3. We confirm the versatility of the C-MoO3 NR anodes by preparing flexible batteries that display stable performance, even in bent state. This simple approach toward C-MoO3 NR anodes proceeds without rigorous chemical synthesis or extremely high temperatures, making it a scalable solution to prepare high-capacity anodes for next-generation LIBs.

  16. Facile Synthesis of SrCO3-Sr(OH2/PPy Nanocomposite with Enhanced Photocatalytic Activity under Visible Light

    Directory of Open Access Journals (Sweden)

    Alfredo Márquez-Herrera

    2016-01-01

    Full Text Available Pyrrole monomer was chemically polymerized onto SrCO3-Sr(OH2 powders to obtain SrCO3-Sr(OH2/polypyrrole nanocomposite to be used as a candidate for photocatalytic degradation of methylene blue dye (MB. The material was characterized by Fourier transform infrared (FTIR spectroscopy, UV/Vis spectroscopy, and X-ray diffraction (XRD. It was observed from transmission electronic microscopy (TEM analysis that the reported synthesis route allows the production of SrCO3-Sr(OH2 nanoparticles with particle size below 100 nm which were embedded within a semiconducting polypyrrole matrix (PPy. The SrCO3-Sr(OH2 and SrCO3-Sr(OH2/PPy nanocomposites were tested in the photodegradation of MB dye under visible light irradiation. Also, the effects of MB dye initial concentration and the catalyst load on photodegradation efficiency were studied and discussed. Under the same conditions, the efficiency of photodegradation of MB employing the SrCO3-Sr(OH2/PPy nanocomposite increases as compared with that obtained employing the SrCO3-Sr(OH2 nanocomposite.

  17. Facile Synthesis of Cu2O/RGO/Ni(OH)2 Nanocomposite and its Double Synergistic Effect on Supercapacitor Performance

    International Nuclear Information System (INIS)

    Wang, Kun; Zhao, Chongjun; Min, Shudi; Qian, Xiuzhen

    2015-01-01

    ABSTRACT: A nanocomposite for supercapacitor electrode materials was designed and developed by integrating partially disabled Cu 2 O (low specific capacity, but high cycling ability) and Ni(OH) 2 (low cyclability and high specific capacity) in the presence of reduced graphene oxide (RGO) nanosheets. Nanocomposite of Cu 2 O/RGO/Ni(OH) 2 was directly grown on nickel foam (NF) through a facile one-pot hydrothermal process without any other reductant or oxidant, in which nickel foam acted as both a reductant of GO and Ni source, and a substrate for nanocomposite. The resultant Cu 2 O/RGO/Ni(OH) 2 nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectrometer (XPS), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The electrochemical performance of the as-synthesized Cu 2 O/RGO/Ni(OH) 2 /NF electrodes were evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectrometry (EIS) in 6 mol L −1 KOH aqueous solution. This Cu 2 O/RGO/Ni(OH) 2 nanocomposite exhibits superior capacitive performance: high capability (3969.3 mF cm −2 at 30 mA cm −2 , i.e., 923.1 F g −1 at 7.0 A g −1 ), excellent cycling stability (92.4% retention even after 4,000 cycles, for RGO/Ni(OH) 2 /NF, 92.3% after 1,000 cycles), and good rate capacitance (50.3% capacity remaining at 200 mA cm −2 )

  18. Facile synthesis of graphene oxide @ mesoporous carbon hybrid nanocomposites for lithium sulfur battery

    International Nuclear Information System (INIS)

    Bao, Weizhai; Zhang, Zhian; Chen, Wei; Zhou, Chengkun; Lai, Yanqing; Li, Jie

    2014-01-01

    Graphical abstract: - Highlights: • A novel design and synthesis of GO@Meso-C using GO@MOF-5 as precursor. • GO@Meso-C hybrid material as a host material was applied for sulfur cathode. • Electrochemical performances were improved in sulfur cathode using Go@Meso-C. - Abstract: We present a design and synthesis of a hierarchical architecture of graphene oxide @ mesoporous carbon (GO@Meso-C) using graphene oxide @ metal-organic framework hybrid materials (GO@MOF-5) as both the template and precursor. Active sulfur is encapsulated into the GO@Meso-C matrix prepared via carbonize GO@MOF-5 polyhedrons for high performance lithium sulfur battery. The initial and 100th cycle discharge capacity of GO@Meso-C/S sulfur cathode are as high as 1122 mAh g −1 and 820 mAh g −1 at a current rate of 0.2 C. The remarkably high special capacity and capacity retention rate indicate that the GO@Meso-C is a promising host material for the sulfur cathode in the lithium sulfur battery applications

  19. A facile synthesis and spectral characterization of Cu{sup 2+} doped CdO/ZnS nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Joyce Stella, R.; Thirumala Rao, G.; Babu, B.; Pushpa Manjari, V. [Department of Physics, University College of Sciences, Acharya Nagarjuna University, Nagarjuna Nagar, AP 522510 (India); Reddy, Ch. Venkata; Shim, Jaesool [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Ravikumar, R.V.S.S.N., E-mail: rvssn@yahoo.co.in [Department of Physics, University College of Sciences, Acharya Nagarjuna University, Nagarjuna Nagar, AP 522510 (India)

    2015-06-15

    A facile two-step method is demonstrated for the preparation of Cu{sup 2+} doped CdO/ZnS nanocomposite. Systematic investigations like X-ray diffraction (XRD), Scanning electron microscopy (SEM) with EDS, transmission electron microscopy (TEM), FT-IR, electron paramagnetic resonance (EPR), optical absorption, photoluminescence (PL) and magnetic studies are carried out for the prepared material. From powder XRD, the nanocomposites are comprised for cubic phase of both CdO and ZnS in a close contact with each other. The ground state wave function of dopant ions has been estimated from EPR studies. Optical and EPR data confirm that doped Cu{sup 2+}ions occupy rhombically distorted octahedral sites with the host material. Due to doping, band gap has been changed and blue shifts occurred in PL. Magnetic measurements indicate a possible ferromagnetic response, associated to the exchange interaction between local spin-polarized electrons of Cu{sup 2+} ions and conductive electrons. - Graphical abstract: M–H curve of Cu{sup 2+} doped CdO–ZnS nanocomposites. The magnetic properties of Cu{sup 2+} doped CdO/ZnS nanocomposite has been investigated using vibrating sample magnetometer given as magnetization and hysteresis (M–H) curve. The magnetization curve with noticeable coercivity of M–H loop clearly indicate the existence of ferromagnetic ordering in Cu{sup 2+} doped CdO/ZnS nanocomposite at room temperature. According to the Ruderman–Kittel–Kasuya–Yosida (RKKY) theory, the exchange interaction between local spin-polarized electrons (such as the electrons of Cu{sup 2+} ions) and conductive electrons is the main cause that leads to the ferromagnetism. Coercivity (Hc) of the field is about 98 Oe, saturation magnetization (Ms) and remnant magnetization (Mr) of present sample is estimated to be 15.8×10{sup −3} and 1.43×10{sup −3} emu/g respectively. The ferromagnetism observed in the prepared material is not commencing with other impurities but expected to

  20. Facile synthesis of surface-functionalized magnetic nanocomposites for effectively selective adsorption of cationic dyes

    Science.gov (United States)

    Hua, Yani; Xiao, Juan; Zhang, Qinqin; Cui, Chang; Wang, Chuan

    2018-04-01

    A new magnetic nano-adsorbent, polycatechol modified Fe3O4 magnetic nanoparticles (Fe3O4/PCC MNPs) were prepared by a facile chemical coprecipitation method using iron salts and catechol solution as precursors. Fe3O4/PCC MNPs owned negatively charged surface with oxygen-containing groups and showed a strong adsorption capacity and fast adsorption rates for the removal of cationic dyes in water. The adsorption capacity of methylene blue (MB), cationic turquoise blue GB (GB), malachite green (MG), crystal violet (CV) and cationic pink FG (FG) were 60.06 mg g- 1, 70.97 mg g- 1, 66.84 mg g- 1, 66.01 mg g- 1 and 50.27 mg g- 1, respectively. The adsorption mechanism was proposed by the analyses of the adsorption isotherms and adsorption kinetics of cationic dyes on Fe3O4/PCC MNPs. Moreover, the cationic dyes adsorbed on the MNPs as a function of contact time, pH value, temperature, coexisting cationic ions and ion strength were also investigated. These results suggested that the Fe3O4/PCC MNPs is promising to be used as a magnetic adsorbent for selective adsorption of cationic dyes in wastewater treatment.

  1. Facile synthesis of NiWO4/reduced graphene oxide nanocomposite with excellent capacitive performance for supercapacitors

    International Nuclear Information System (INIS)

    Xu, Xiaowei; Pei, Liyuan; Yang, Yang; Shen, Jianfeng; Ye, Mingxin

    2016-01-01

    NiWO 4 /reduced graphene oxide (NWG) nanocomposite was successfully synthesized through a facile one-pot solvothermal method for the first time. The resulting nanocomposite is composed of NiWO 4 nanoparticles that are uniformly attached on graphene sheets by in situ reducing. The as-prepared NWG composite has been systematically characterized by Powder X-ray diffraction, Fourier transform infrared spectra, Raman spectroscopy, Thermogravimetric analysis, Scanning electron microscopy, Transmission electron microscopy, X-ray photoelectron spectra, and Brunauer–Emmett–Teller analysis. The capacitive performances of the as-prepared NWG composite as electrode material are investigated. It is found that the NWG composite exhibits a high specific capacitance up to 1031.3 F g −1 at a current density of 0.5 A g −1 . The greatly enhanced capacitive performance of the NWG electrode can be attributed to the synergetic effect of NiWO 4 nanoparticles and RGO, which provides conducting channels and active sites. The cyclic stability tests demonstrated no decreases of its initial values after 5000 cycles, suggesting that such hybrid electrode possesses a great potential application in energy-storage devices. - Highlights: • NiWO 4 /RGO composite was successfully prepared through a facile solvothermal method. • The NiWO 4 /RGO composite shows a high specific capacitance of 1031.3 F g −1 . • Enhanced electrical conductivity leads to superior electrochemical performance.

  2. Facile, low temperature synthesis of SnO_2/reduced graphene oxide nanocomposite as anode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Hou, Chau-Chung; Brahma, Sanjaya; Weng, Shao-Chieh; Chang, Chia-Chin; Huang, Jow-Lay

    2017-01-01

    Highlights: • Facile, one-pot, low temperature synthesis of SnO_2-RGO composite. • In-situ reduction of graphene oxide and growth of SnO_2 nanoparticle. • Concentration of reductant during synthesis affects the properties significantly. • SnO_2-RGO composite shows good rate capability and stable capacitance. • Synthesis method is energy efficient and scalable for other metal oxides. - Abstract: We demonstrate a facile, single step, low temperature and energy efficient strategy for the synthesis of SnO_2-reduced graphene oxide (RGO) nanocomposite where the crystallization of SnO_2 nanoparticles and the reduction of graphene oxide takes place simultaneously by an in situ chemical reduction process. The electrochemical property of the SnO_2-RGO composite prepared by using low concentrations of reducing agent shows better Li storage performance, good rate capability (378 mAh g"−"1 at 3200 mA g"−"1) and stable capacitance (522 mAh g"−"1 after 50 cycles). Increasing the reductant concentration lead to crystallization of high concentration of SnO_2 nanoparticle aggregation and degrade the Li ion storage property.

  3. Facile, low temperature synthesis of SnO{sub 2}/reduced graphene oxide nanocomposite as anode material for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Chau-Chung; Brahma, Sanjaya; Weng, Shao-Chieh [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70001, Taiwan, ROC (China); Chang, Chia-Chin [Department of Greenergy, National University of Tainan, Tainan 70005, Taiwan, ROC (China); Huang, Jow-Lay, E-mail: jlh888@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70001, Taiwan, ROC (China); Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan, ROC (China); Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 70101, Taiwan, ROC (China)

    2017-08-15

    Highlights: • Facile, one-pot, low temperature synthesis of SnO{sub 2}-RGO composite. • In-situ reduction of graphene oxide and growth of SnO{sub 2} nanoparticle. • Concentration of reductant during synthesis affects the properties significantly. • SnO{sub 2}-RGO composite shows good rate capability and stable capacitance. • Synthesis method is energy efficient and scalable for other metal oxides. - Abstract: We demonstrate a facile, single step, low temperature and energy efficient strategy for the synthesis of SnO{sub 2}-reduced graphene oxide (RGO) nanocomposite where the crystallization of SnO{sub 2} nanoparticles and the reduction of graphene oxide takes place simultaneously by an in situ chemical reduction process. The electrochemical property of the SnO{sub 2}-RGO composite prepared by using low concentrations of reducing agent shows better Li storage performance, good rate capability (378 mAh g{sup −1} at 3200 mA g{sup −1}) and stable capacitance (522 mAh g{sup −1} after 50 cycles). Increasing the reductant concentration lead to crystallization of high concentration of SnO{sub 2} nanoparticle aggregation and degrade the Li ion storage property.

  4. Facile synthesis of Cu2O/CuO/RGO nanocomposite and its superior cyclability in supercapacitor

    International Nuclear Information System (INIS)

    Wang, Kun; Dong, Xiangmao; Zhao, Chongjun; Qian, Xiuzhen; Xu, Yunlong

    2015-01-01

    A reduced graphene oxide (RGO)-based nanocomposite of redox counterpart of the oxides of Cu(I)-Cu(II) pair for Faradaic reaction, Cu 2 O/CuO/RGO, was controllably synthesized through a facile, eco-friendly one-step hydrothermal-assisted redox reaction of elemental Cu and graphene oxide (GO) without the addition of any other reagents. The resultant Cu 2 O/CuO/RGO nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, Thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). It is found that, when dealloyed nanoporous Cu was used as a Cu source, the uniform spherical Cu 2 O/CuO nanoparticles with double size scales (∼25 nm and ∼5 nm) were anchored on RGO sheets. This Cu 2 O/CuO/RGO nanocomposite redox counterpart exhibits improved rate capability and excellent cycling stability, i.e., only ca. 21.4% of the capacity was lost when the discharge current density increases from 1 A g −1 (173.4 F g −1 ) to 10 A g −1 (136.3 F g −1 ). Especially, the capacity remains almost unchanged (98.2%) after 100,000 cycles at 10 A g −1 . The good electrochemical performance and simple accessibility prove that this Cu 2 O/CuO/RGO composite consisting of a pair of redox counterparts is a promising material for supercapacitor applications

  5. A facile synthesis of graphene oxide–ZnS/ZnO nanocomposites and observations of thermal quenching of visible photoluminescence emission and nonlinear optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Kole, A.K.; Biswas, S. [Nanoscience Laboratory, Dept. of Physics, National Institute of Technology, Durgapur 713209, West Bengal (India); Tiwary, C.S. [Department of Materials Engineering, Indian Institute of Science, Bangalore (India); Kumbhakar, P., E-mail: pathik.kumbhakar@phy.nitdgp.ac.in [Nanoscience Laboratory, Dept. of Physics, National Institute of Technology, Durgapur 713209, West Bengal (India)

    2016-11-15

    Here we have reported a facile synthesis of graphene oxide–ZnS/ZnO nanocomposite and the temperature dependent photoluminescence (PL) emissions in the synthesized materials, which are scarcely been available in the literature. In the present work PL emission in GO and its composites with ZnS and ZnO semiconductor quantum dots (QDs) have been measured at variable temperatures in 283–353 K temperature region. From the measured results it has been found that quenching of PL emission has been taken place in the composite sample and it has been proposed that as the temperature is increased, the excited electrons in the localized states formed by the sp{sup 2} clusters in GO can migrate to the nearby sp{sup 3} defects states, thereby the intensity of PL emission is reduced. Nonlinear Optical (NLO) properties as well as the optical limiting (OL) properties has also been studied by using an indigenously developed Z-scan technique with a 10 ns laser pulse at 1064 nm laser radiation. Two photon absorptions (2PA) behavior have been found to be the dominant mechanism in the synthesized samples. A suitable energy level scheme has been proposed to explain the observed PL emission behavior as well as the 2PA mechanism. The present report will open up a lot of prospects for synthesizing GO-semiconductor nanocomposites with semiconductor materials as well as for potential applications in future luminescent devices.

  6. Synthesis, characterization, and Fischer–Tropsch performance of cobalt/zinc aluminate nanocomposites via a facile and corrosion-free coprecipitation route

    International Nuclear Information System (INIS)

    Liu, Zhenxin; Xing, Yu; Xue, Yingying; Wu, Depeng; Fang, Shaoming

    2015-01-01

    Literature about ZnAl 2 O 4 -supported cobalt Fischer–Tropsch synthesis (FTS) catalytic materials is sparse. A series of cobalt-containing nanocomposites, supported by nanosized ZnAl 2 O 4 spinel (i.e., a complex oxide of about 6.4 nm) or alumina (i.e., a simple oxide of about 6.2 nm), were prepared via urea-gelation, coprecipitation, or impregnation methods followed by stepwise reduction. These materials were examined by XRD, TGA, nitrogen sorption, FESEM, and EDS. Effects of corrosion and pore size distributions on materials preparation were also investigated. The “coprecipitation/stepwise reduction” route is facile and suitable to prepare nanosized ZnAl 2 O 4 -supported Co 0 nanocomposites. At similar CO conversions, the coprecipitated Co/ZnAl 2 O 4 exhibits significantly lower C 1 hydrocarbon distribution, slightly lower C 5+ hydrocarbon distribution, significantly higher C 2 –C 4 hydrocarbon distribution, and significantly higher olefin/paraffin ratio of C 2 –C 4 than Co/γ-Al 2 O 3

  7. Green synthesis of graphene/Ag nanocomposites

    International Nuclear Information System (INIS)

    Yuan Wenhui; Gu Yejian; Li Li

    2012-01-01

    Graphical abstract: A facile and green approach to synthesis of GNS/AgNPs is reported by employing sodium citrate as reductant, and this study represents the use of biocompounds for nontoxic and scalable production of GNS/AgNPs under a suitable concentration of silver ions and the prepared GNS/AgNPs can be used in the field of disinfection. Highlights: ► Graphene/Ag nanocomposites were prepared by a green and facile strategy based on sodium citrate. ► The influence of AgNO 3 amount on particle size and size range of AgNPs was studied. ► The surface plasmon resonance properties of AgNPs on graphene was investigated. ► The antibacterial activity of silver nanoparticles was retained in the nanocomposites. - Abstract: Graphene/Ag nanocomposites (GNS/AgNPs) were fabricated via a green and facile method, employing graphite oxide (GO) as a precursor of graphene, AgNO 3 as a precursor of Ag nanoparticles, and sodium citrate as an environmentally friendly reducing and stabilizing agent. The synthesized GNS/AgNPs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Raman spectra (RS), respectively. The results indicated that graphite oxide was completely reduced to graphene, and the silver ion was reduced by sodium citrate simultaneously. Under a suitable dosage of silver ions, well-dispersed AgNPs on the graphene sheets mostly centralized at 20–25 nm. The surface plasmon resonance property of AgNPs on graphene showed that there was a interaction between AgNPs and graphene supports. In addition, antibacterial activity of silver nanoparticles was retained in the nanocomposites, suggesting that they can be potentially used as a graphene-based biomaterial.

  8. Radiolytic Synthesis of Magnetic Nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Grdanovska, Slavica; Tissot, Chanel; Barkatt, Aaron; Al-Sheikhly, Mohamad [Nuclear Engineering Program – Department of Materials Science and Engineering, University of Maryland, College Park, MD (United States)

    2011-07-01

    Magnetic nanocomposites, in which magnetic nanoparticles are encapsulated in polymeric matrices, have important applications in medicine, electronics and mechanical devices. However, the development of processes leading to magnetic nanocomposites with desirable, predictable and reproducible properties has turned out to be a difficult challenge. To date, most studies have concentrated on a magnetic oxide, primarily magnetite (Fe{sub 3}O{sub 4}), as the encapsulated phase. However, the synthesis of batches of magnetite with homogeneous properties at reasonably low temperature is a delicate operation. Indeed, commercial lots of magnetite powder, despite having bulk Fe{sub 3}O{sub 4} stoichiometry, turn out to have large variations in structure and in magnetic properties. The difficulties in controlling the product are greatly magnified when the particle size is in the nanometer range.

  9. Synthesis of polyanthranilic acid–Au nanocomposites by emulsion ...

    Indian Academy of Sciences (India)

    Polyanthranilic acid (PANA) and polyanthranilic acid–gold (PANA–Au) nanocomposites have been synthesized through emulsion polymerization technique. Use of gold chloride as an oxidant for anthranilic acid not only provides a new route for chemical synthesis of PANA, but also explores a facile method for the formation ...

  10. A facile synthesis of a novel optoelectric material: a nanocomposite of SWCNT/ZnO nanostructures embedded in sulfonated polyaniline

    Directory of Open Access Journals (Sweden)

    Rajesh K. Agrawalla

    2014-07-01

    Full Text Available Functionalized single-walled carbon nanotubes (f-SWCNTs hybridized with freshly prepared zinc oxide (ZnO nanocrystals have been found to be good luminescent material with tuned emission properties. A three-phase nanocomposite of sulfonated polyaniline embedded with such SWCNT/ZnO nanostructures has been prepared by a simple solution mixing chemical process and characterized by using high-resolution transmission electron microscopy, X-ray diffractometry, Raman spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The study of UV-visible absorption and photoluminescence spectroscopies reveal that the ternary polymer nanocomposite is a luminescent material with enhanced emission intensity. Also an increase in DC conductivity indicates that the nanocomposite is also a good conductive material, satisfying Mott’s variable range hopping model for a two-dimensional conduction. Such a three-phase nanocomposite may find extensive application in dye-sensitized solar cells, sensors, and supercapacitors.

  11. Facile synthesis of gold-capped TiO2 nanocomposites for surface-enhanced Raman scattering

    International Nuclear Information System (INIS)

    Han, Di; Huang, Hao; Du, Deyang; Lang, Xianzhong; Long, Kailin; Hao, Qi; Qiu, Teng

    2015-01-01

    A convenient technique was developed to fabricate gold-capped TiO 2 nanocomposites as robust, cost-efficient and recyclable surface-enhanced Raman scattering (SERS) substrates. The morphologies of obtained nanocomposites exhibit nanotube, nanolace, and nanopore nanostructures by adjusting TiO 2 anodization parameters. As an illustration, dramatic enhancement is achieved using Rhodamine 6G as a molecular probe. Owing to activation by the incident laser beam, the localized electromagnetic field on the nanocomposite surface can be enhanced subsequently amplifying the Raman signal. The topography can be further tuned to optimize the enhancement factor by adjusting the time of gold evaporation. Finite-difference time-domain calculations indicate the nanopore structure may possess excellent SERS characteristic due to the high density of hot spots. In addition, the substrate can be self-cleaned under ultraviolet irradiation due to the superior photocatalytic capacity of the Au–TiO 2 nanocomposites. Our Au–TiO 2 nanocomposites with highly SERS-active properties and recyclability shows promising applications in the detection and treatment of pollutants. - Highlights: • Au–TiO 2 nanocomposites with different morphologies were fabricated. • Au–TiO 2 nanopore shows pronounced SERS compared with nanotube and nanolace. • The size of the gold nanocaps on Au–TiO 2 nanopore was tailored to optimize the SERS. • FDTD simulations indicate excellent SERS attributes to the high density of hot spots. • Au–TiO 2 nanocomposites prove to be recyclable substrates for SERS detection

  12. Superparamagnetic magnetite nanocrystals-graphene oxide nanocomposites: facile synthesis and their enhanced electric double-layer capacitor performance.

    Science.gov (United States)

    Wang, Qihua; Wang, Dewei; Li, Yuqi; Wang, Tingmei

    2012-06-01

    Superparamagnetic magnetite nanocrystals-graphene oxide (FGO) nanocomposites were successfully synthesized through a simple yet versatile one-step solution-processed approach at ambient conditions. Magnetite (Fe3O4) nanocrystals (NCs) with a size of 10-50 nm were uniformly deposited on the surfaces of graphene oxide (GO) sheets, which were confirmed by transmission electron microscopy (TEM) and high-angle annular dark field scanning transmission election microscopy (HAADF-STEM) studies. FGO with different Fe3O4 loadings could be controlled by simply manipulating the initial weight ratio of the precursors. The M-H measurements suggested that the as-prepared FGO nanocomposites have a large saturation magnetizations that made them can move regularly under an external magnetic field. Significantly, FGO nanocomposites also exhibit enhanced electric double-layer capacitor (EDLC) activity compared with pure Fe3O4 NCs and GO in terms of specific capacitance and high-rate charge-discharge.

  13. Polymer nanotube nanocomposites: synthesis, properties, and applications

    National Research Council Canada - National Science Library

    Mittal, Vikas

    2010-01-01

    ... in these commercially important areas of polymer technology. It sums up recent advances in nanotube composite synthesis technology, provides basic introduction to polymer nanotubes nanocomposite technology for the readers new to this field, provides valuable...

  14. Facile synthesis of mesoporous NiFe2O4/CNTs nanocomposite cathode material for high performance asymmetric pseudocapacitors

    Science.gov (United States)

    Kumar, Nagesh; Kumar, Amit; Huang, Guan-Min; Wu, Wen-Wei; Tseng, Tseung Yuen

    2018-03-01

    Morphology and synergistic effect of constituents are the two very important factors that greatly influence the physical, chemical and electrochemical properties of a composite material. In the present work, we report the enhanced electrochemical performance of mesoporous NiFe2O4 and multiwall carbon nanotubes (MWCNTs) nanocomposites synthesized via hexamethylene tetramine (HMT) assisted one-pot hydrothermal approach. The synthesized cubic phase spinel NiFe2O4 nanomaterial possesses high specific surface area (148 m2g-1) with narrow mesopore size distribution. The effect of MWCNTs addition on the electrochemical performance of nanocomposite has been probed thoroughly in a normal three electrode configuration using 2 M KOH electrolyte at room temperature. Experimental results show that the addition of mere 5 mg MWCNTs into fixed NiFe2O4 precursors amount enhances the specific capacitance up to 1291 F g-1 at 1 A g-1, which is the highest reported value for NiFe2O4 nanocomposites so far. NiFe2O4/CNT nanocomposite exhibits small relaxation time constant (1.5 ms), good rate capability and capacitance retention of 81% over 500 charge-discharge cycles. This excellent performance can be assigned to high surface area, mesoporous structure of NiFe2O4 and conducting network formed by MWCNTs in the composite. Further, to evaluate the device performance of the composite, an asymmetric pseudocapacitor has been designed using NiFe2O4/CNT nanocomposite as a positive and N-doped graphene as a negative electrode material, respectively. Our designed asymmetric pseudocapacitor gives maximum energy density of 23 W h kg-1 at power density of 872 W kg-1. These promising results assert the potential of synthesized nanocomposite in the development of efficient practical high-capacitive energy storage devices.

  15. Facile synthesis of core–shell structured PANI-Co_3O_4 nanocomposites with superior electrochemical performance in supercapacitors

    International Nuclear Information System (INIS)

    Hai, Zhenyin; Gao, Libo; Zhang, Qiang; Xu, Hongyan; Cui, Danfeng; Zhang, Zengxing; Tsoukalas, Dimitris; Tang, Jun; Yan, Shubin; Xue, Chenyang

    2016-01-01

    Graphical abstract: - Highlights: • PANI-Co_3O_4 is synthesized by carbon-assisted and in situ polymerization methods. • PANI coating improves the properties of Co_3O_4 affecting electrochemical performance. • The nanocomposites exhibit a high specific capacitance of 1184 F g"−"1 at 1.25 A g"−"1. - Abstract: Core–shell structured PANI-Co_3O_4 nanocomposites for supercapacitor applications were synthesized by combination of carbon-assisted method and in situ polymerization method. The crystalline structure, optical band gap, morphology, and hydrophilic property, as the major factors affecting the performances of supercapacitors, were investigated by X-ray diffraction (XRD), UV–vis spectrophotometry (UV–vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and water contact angle (WCA). The core–shell structured PANI-Co_3O_4 nanocomposites are characterized by amorphous PANI, small bandgaps, large surface area and favorable hydrophilicity, which indicates the superior electrochemical performances of the nanocomposites as electrode material for supercapacitors. Cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) measurements were conducted in 6 M KOH aqueous solution to evaluate the electrochemical performances. The results shows that core–shell structured PANI-Co_3O_4 nanocomposites exhibit a high specific capacitance of 1184 F g"−"1 at 1.25 A g"−"1, excellent cycling stability of a capacitance retention of 84.9% after 1000 galvanostatic charge/discharge cycles, good electrical conductivity and ion diffusion behavior.

  16. Silk Fiber as the Support and Reductant for the Facile Synthesis of Ag–Fe3O4 Nanocomposites and Its Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    Xiaonan Liu

    2016-06-01

    Full Text Available We report a facile and environmentally friendly approach to prepare Ag–Fe3O4–silk fiber nanocomposites. The Ag–Fe3O4–silk fiber acts as: (i a biocompatible support for the silver nanoparticles; and (ii a reducing agent for the silver ions. Neither additional reducing agents nor toxic organic solvents were used during the preparation process. The Ag–Fe3O4–silk fiber nanocomposites can be actuated by a small household magnet and have high antibacterial activities against both Escherichia coli and Staphylococcus aureus. These nanocomposites could be easily recycled without a decrease in their antibacterial activities due to the synergistic effects between the Ag NPs and Fe3O4 NPs with large amounts of active sites.

  17. Facile synthesis of cuprous oxide nanowires decorated graphene oxide nanosheets nanocomposites and its application in label-free electrochemical immunosensor.

    Science.gov (United States)

    Wang, Huan; Zhang, Yong; Wang, Yulan; Ma, Hongmin; Du, Bin; Wei, Qin

    2017-01-15

    In this work, the assembly between one-dimensional (1D) nanomaterials and two-dimensional (2D) nanomaterials was achieved by a simple method. Cuprous oxide nanowires decorated graphene oxide nanosheets (Cu 2 O@GO) nanocomposites were synthesized for the first time by a simple electrostatic self-assembly process. The nanostructure was well confirmed by scanning electron microscope (SEM) and transmission electron microscope (TEM) images. Taking advantages of good electrocatalytic activity and high specific surface area of Cu 2 O@GO nanocomposites, a label-free electrochemical immunosensor was developed by employing Cu 2 O@GO as signal amplification platform for the quantitative detection of alpha fetoprotein (AFP). In addition, toluidine blue (TB) was used as the electron transfer mediator to provide the electrochemical signal, which was adsorbed on graphene oxide nanosheets (GO NSs) by electrostatic attraction. The detection mechanism was based on the monitoring of the electrochemical current response change of TB by the square wave voltammetry (SWV) when immunoreaction occurred on the surface of electrode. Under optimal conditions, the proposed immunosensor displayed a high sensitivity and a low detection limit. This designed method may provide an effective method in the clinical diagnosis of AFP and other tumor markers. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Facile sonochemical synthesis of Zn2SnO4-V2O5 nanocomposite as an effective photocatalyst for degradation of Eosin Yellow.

    Science.gov (United States)

    Ramasamy Raja, V; Rosaline, D Rani; Suganthi, A; Rajarajan, M

    2018-06-01

    This study presents a novel method for the preparation of Zn 2 SnO 4 /V 2 O 5 nanocomposites via a sonochemical aqueous route. This method is mild, convenient, cheap and efficient. The as prepared samples were characterized by XRD, SEM, EDAX, TEM, BET, FT-IR and UV-DRS spectra. DRS spectrum shows the adsorption edge of Zn 2 SnO 4 -V 2 O 5 in visible region of spectrum. The structural and morphological features of the as synthesized Zn 2 SnO 4 -V 2 O 5 nanocomposites have been observed using both scanning and transmission electron microscopy. BET surface area analysis inferred that the prepared hetero-junctions are meso-porous in nature. The photocatalytic activity of Zn 2 SnO 4 -V 2 O 5 nanocomposites for the degradation of Eosin Yellow (EY) dye under visible light was investigated in detail. 3% Zn 2 SnO 4 -V 2 O 5 nanocomposite exhibited the highest photocatalytic performance (92% of EY degradation) when compared with 2% Zn 2 SnO 4 -V 2 O 5 and 5% Zn 2 SnO 4 -V 2 O 5 . The adsorption of Eosin Yellow followed the pseudo-first order kinetic model. Simultaneously, high stability of the sample was also investigated by four successive photodegradation of EY under visible light. The relationship between photocatalytic activity and the structure of 3% Zn 2 SnO 4 -V 2 O 5 nanocomposite is discussed, and possible reaction mechanisms are also proposed. Therefore, the facile sonochemical preparation process provides some insight into the application of Zn 2 SnO 4 -V 2 O 5 nanocomposites in photocatalytic degradation of organic pollutants. Copyright © 2018. Published by Elsevier B.V.

  19. A facile synthesis of Zn(x)Cd(1-x)S/CNTs nanocomposite photocatalyst for H2 production.

    Science.gov (United States)

    Wang, Lei; Yao, Zhongping; Jia, Fangzhou; Chen, Bin; Jiang, Zhaohua

    2013-07-21

    The sulfide solid solution has become a promising and important visible-light-responsive photocatalyst for hydrogen production nowadays. Zn(x)Cd(1-x)S/CNT nanocomposites were synthesized to improve the dispersion, adjust the energy band gap, and enhance the separation of the photogenerated electrons and holes. The as-prepared photocatalysts were characterized by scanning electron-microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse reflectance spectra (UV-visible), respectively. And the effects of CNTs on structure, composition and optical absorption property of the sulfide solid solutions were investigated along with their inherent relationships. For Zn0.83Cd0.17S/CNTs, sulfide solid solution is assembled along the CNTs orderly, with a diameter of 100 nm or so. XPS analysis shows that there is bonding effect between the solid solutions and the CNTs due to the strong adsorption of Zn(2+) and Cd(2+) on the surface of CNTs. There are two obvious absorption edges for Zn0.83Cd0.17S/CNTs, corresponding to two kinds of sulfide solid solutions with different molar ratios of Zn/Cd. The hybridization of solid solutions with CNTs makes the absorption spectrum red shift. The photocatalytic property was evaluated by splitting Na2S + Na2SO3 solution into H2, and the highest rate of H2 evolution of 6.03 mmol h(-1) g(-1) was achieved over Zn0.83Cd0.17S/CNTs. The high activity of photocatalytic H2 production is attributed to the following factors: (1) the optimum band gap and a moderate position of the conduction band (which needs to match the irradiation spectrum of the Xe lamp best), (2) the efficient separation of photogenerated electrons and holes by hybridization, and (3) the improvement of the dispersion of nanocomposites by assembling along the CNTs as well.

  20. Facile synthesis of a platinum-lead oxide nanocomposite catalyst with high activity and durability for ethanol electrooxidation.

    Science.gov (United States)

    Yang, Wei-Hua; Wang, Hong-Hui; Chen, De-Hao; Zhou, Zhi-You; Sun, Shi-Gang

    2012-12-21

    Aimed at searching for highly active and stable nano-scale Pt-based catalysts that can improve significantly the energy conversion efficiency of direct ethanol fuel cells (DEFCs), a novel Pt-PbO(x) nanocomposite (Pt-PbO(x) NC) catalyst with a mean size of 3.23 nm was synthesized through a simple wet chemistry method without using a surfactant, organometallic precursors and high temperature. Electrocatalytic tests demonstrated that the as-prepared Pt-PbO(x) NC catalyst possesses a much higher catalytic activity and a longer durability than Pt nanoparticles (nm-Pt) and commercial Pt black catalysts for ethanol electrooxidation. For instance, Pt-PbO(x) NC showed an onset potential that was 30 mV and 44 mV less positive, together with a peak current density 1.7 and 2.6 times higher than those observed for nm-Pt and Pt black catalysts in the cyclic voltammogram tests. The ratio of current densities per unit Pt mass on Pt-PbO(x) NC, nm-Pt and Pt black catalysts is 27.3 : 3.4 : 1 for the long-term (2 hours) chronoamperometric experiments measured at -0.4 V (vs. SCE). In situ FTIR spectroscopic studies revealed that the activity of breaking C-C bonds of ethanol of the Pt-PbO(x) NC is as high as 5.17 times that of the nm-Pt, which illustrates a high efficiency of ethanol oxidation to CO(2) on the as-prepared Pt-PbO(x) NC catalyst.

  1. A facile hydrothermal strategy for synthesis of SnO2 nanorods-graphene nanocomposites for high performance photocatalysis.

    Science.gov (United States)

    Chen, Lu-Ya; Zhang, Wei-De; Xu, Bin; Yu, Yu-Xiang

    2012-09-01

    In this study, we report a facilely hydrothermal process for synthesizing SnO2 nanorods-graphene (SnO2 nanorods-GR) composite using graphite oxide and SnCl4 as raw materials. The SnO2 nanorods-GR composite was characterized by X-ray diffraction, electron microscopy, Xray photoelectron spectroscopy, and thermogravimetric analysis. Compared to commercial TiO2 nanoparticles P25 and neat SnO2 nanorods, the SnO2 nanorods-GR composite exhibits higher photocatalytic activity under UV light irradiation. The mechanism of its high photocatalytic activity is mainly ascribed to the synergy effect between SnO2 and graphene, in which graphene acts as an adsorbent and electron acceptor due to its large structure of pi-pi conjugation from sp2 hybrid carbon atoms. The results demonstrated in this study provide a promising way to enhance the photocatalytic activity by compounding semiconductive nanocrystals with graphene.

  2. Facile synthesis and characterization of N-doped TiO2/C nanocomposites with enhanced visible-light photocatalytic performance

    Science.gov (United States)

    Jia, Tiekun; Fu, Fang; Yu, Dongsheng; Cao, Jianliang; Sun, Guang

    2018-02-01

    Ultrafine anatase N-doped TiO2 nanocrystals modified with carbon (denoted as N-doped TiO2/C) were successfully prepared via a facile and low-cost approach, using titanium tetrachloride, aqueous ammonia and urea as starting materials. The phase composition, surface chemical composition, morphological structure, electronic and optical properties of the as-prepared photocatalysts were well characterized and analyzed. On the basis of Raman spectral characterization combining with the results of X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM), it could be concluded that N dopant ions were successfully introduced into TiO2 crystal lattice and carbon species were modified on the surface or between the nanoparticles to form N-doped TiO2/C nanocomposites. Compared with that of bare TiO2, the adsorption band edge of N-doped TiO2/C nanocomposites were found to have an evident red-shift toward visible light region, implying that the bandgap of N-doped TiO2/C nanocomposites is narrowed and the visible light absorption capacity is significantly enhanced due to N doping and carbon modification. The photoactivity of the as-prepared photocatalytsts was tested by the degradation of Rhodamine B (RhB) under visible light (λ > 420 nm), and the results showed that the N-doped TiO2/C nanocomposites exhibited much higher photodegradation rate than pure TiO2 and N-doped TiO2, which was mainly attributed to the synergistic effect of the enhanced light harvesting, augmented catalytic active sites and efficient separation of photogenerated electron-hole pairs.

  3. Polypyrrole-silver Nanocomposite: Synthesis and Characterization

    Directory of Open Access Journals (Sweden)

    D. M. Nerkar

    2016-07-01

    Full Text Available Polypyrrole-Silver (PPy-Ag nanocomposite has been successfully synthesized by the chemical oxidative polymerization of pyrrole with iron (III chloride as an oxidant, in the presence of a colloidal suspension of silver nanoparticles. Turkevich method (Citrate reduction method was used for the synthesis of silver nanoparticles (Ag NPs. The silver nanoparticles were characterized by UV-Visible spectroscopy which showed an absorption band at 423 nm confirming the formation of nanoparticles. PPy-Ag nanocomposite was characterized by Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM, Fourier Transform Infrared Spectroscopy (FTIR and X-ray diffraction (XRD techniques for morphological and structural confirmations. TEM and SEM images revealed that the silver nanoparticles were well dispersed in the PPy matrix. XRD pattern showed that PPy is amorphous but the presence of the peaks at 2q values of 38.24°, 44.57°, 64.51° and 78.45° corresponding to a cubic phase of silver, revealed the incorporation of silver nanoparticles in the PPy matrix. A possible formation mechanism of PPy-Ag nanocomposite was also proposed. The electrical conductivity of PPy-Ag nanocomposite was studied using two probe method. The electrical conductivity of the PPy-Ag nanocomposite prepared was found to be 4.657´10- 2 S/cm, whereas that of pure PPy was found to be 9.85´10-3 S/cm at room temperature (303 K. The value of activation energy (Ea for pure PPy was 0.045 eV while it decreased to 0.034 eV for PPy-Ag nanocomposite. The synthesized nanocomposite powder can be utilized as a potential material for fabrication of gas sensors operating at room temperature.

  4. Polypyrrole-silver Nanocomposite: Synthesis and Characterization

    OpenAIRE

    D. M. Nerkar; S. V. Panse; S. P. Patil; S. E. Jaware; G. G. Padhye

    2016-01-01

    Polypyrrole-Silver (PPy-Ag) nanocomposite has been successfully synthesized by the chemical oxidative polymerization of pyrrole with iron (III) chloride as an oxidant, in the presence of a colloidal suspension of silver nanoparticles. Turkevich method (Citrate reduction method) was used for the synthesis of silver nanoparticles (Ag NPs). The silver nanoparticles were characterized by UV-Visible spectroscopy which showed an absorption band at 423 nm confirming the formation of nanoparticles. P...

  5. Microwave-Assisted Hydrothermal Synthesis of Cellulose/Hydroxyapatite Nanocomposites

    Directory of Open Access Journals (Sweden)

    Lian-Hua Fu

    2016-09-01

    Full Text Available In this paper, we report a facile, rapid, and green strategy for the synthesis of cellulose/hydroxyapatite (HA nanocomposites using an inorganic phosphorus source (sodium dihydrogen phosphate dihydrate (NaH2PO4·2H2O, or organic phosphorus sources (adenosine 5′-triphosphate disodium salt (ATP, creatine phosphate disodium salt tetrahydrate (CP, or D-fructose 1,6-bisphosphate trisodium salt octahydrate (FBP through the microwave-assisted hydrothermal method. The effects of the phosphorus sources, heating time, and heating temperature on the phase, size, and morphology of the products were systematically investigated. The experimental results revealed that the phosphate sources played a critical role on the phase, size, and morphology of the minerals in the nanocomposites. For example, the pure HA was obtained by using NaH2PO4·2H2O as phosphorus source, while all the ATP, CP, and FBP led to the byproduct, calcite. The HA nanostructures with various morphologies (including nanorods, pseudo-cubic, pseudo-spherical, and nano-spherical particles were obtained by varying the phosphorus sources or adjusting the reaction parameters. In addition, this strategy is surfactant-free, avoiding the post-treatment procedure and cost for the surfactant removal from the product. We believe that this work can be a guidance for the green synthesis of cellulose/HA nanocomposites in the future.

  6. Facile synthesis of glucose-functionalized reduced graphene oxide (GFRGO)/poly(vinyl alcohol) nanocomposites for improving thermal and mechanical properties

    International Nuclear Information System (INIS)

    Abdolmaleki, Amir; Mallakpour, Shadpour; Karshenas, Azam

    2017-01-01

    Highlights: • GFRGO composites were synthesized and used for fabrication of PVA/GFRGO NCs. • Attached glucose on RGO enhances RGO interaction with PVA hydroxyl groups. • PVA/GFRGO NCs exhibited enhanced thermal and mechanical properties. • FE-SEM and TEM micrographs prove good dispersion of GFRGO into PVA matrix. - Abstract: In this work, we provided a facile pathway to the modification of reduced graphene oxide (RGO) nanosheets by glucose as a biologically active molecule through covalent functionalization. Then, flexible and smooth poly(vinyl alcohol) (PVA)/glucose-functionalized reduced graphene oxide (PVA/GFRGO) nanocomposite (NC) films were fabricated using 0, 1, 3 and 5 wt% concentrations of RGO-glucose in water. As a reducing sugar, glucose can reduce graphene oxide. Thus, graphene oxide was converted to reduced graphene oxide (RGO) by hydrazine hydrate. Then, RGO was functionalized with glucose to achieve good dispersion in the polymer matrix. Due to the increased interfacial interaction between GFRGO and PVA matrix, the prepared PVA/GFRGO NCs showed a 52% increase in tensile strength and a 47% improvement in Young’s modulus by adding of only 5 wt% of GFRGO. Thermal analysis results showed that the thermal stability of the PVA/GFRGO NCs increased compared to the neat PVA film.

  7. Facile synthesis of glucose-functionalized reduced graphene oxide (GFRGO)/poly(vinyl alcohol) nanocomposites for improving thermal and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Abdolmaleki, Amir, E-mail: abdolmaleki@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Center of Excellence in Sensors and Green Chemistry, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Mallakpour, Shadpour, E-mail: mallak@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Center of Excellence in Sensors and Green Chemistry, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Karshenas, Azam [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2017-03-15

    Highlights: • GFRGO composites were synthesized and used for fabrication of PVA/GFRGO NCs. • Attached glucose on RGO enhances RGO interaction with PVA hydroxyl groups. • PVA/GFRGO NCs exhibited enhanced thermal and mechanical properties. • FE-SEM and TEM micrographs prove good dispersion of GFRGO into PVA matrix. - Abstract: In this work, we provided a facile pathway to the modification of reduced graphene oxide (RGO) nanosheets by glucose as a biologically active molecule through covalent functionalization. Then, flexible and smooth poly(vinyl alcohol) (PVA)/glucose-functionalized reduced graphene oxide (PVA/GFRGO) nanocomposite (NC) films were fabricated using 0, 1, 3 and 5 wt% concentrations of RGO-glucose in water. As a reducing sugar, glucose can reduce graphene oxide. Thus, graphene oxide was converted to reduced graphene oxide (RGO) by hydrazine hydrate. Then, RGO was functionalized with glucose to achieve good dispersion in the polymer matrix. Due to the increased interfacial interaction between GFRGO and PVA matrix, the prepared PVA/GFRGO NCs showed a 52% increase in tensile strength and a 47% improvement in Young’s modulus by adding of only 5 wt% of GFRGO. Thermal analysis results showed that the thermal stability of the PVA/GFRGO NCs increased compared to the neat PVA film.

  8. Facile green synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin nanocomposite in the dual acting fluorine-containing ionic liquid medium for bone substitute applications

    Energy Technology Data Exchange (ETDEWEB)

    Jegatheeswaran, S. [Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi-3, Tamil Nadu (India); Selvam, S. [Laser and Sensor Application Laboratory, Pusan National University, Busan 609735 (Korea, Republic of); Sri Ramkumar, V. [Deptartment of Environmental Biotechnology, School of Environmental, Sciences, Bharathidasan University, Tiruchirappalli, Tamilnadu (India); Sundrarajan, M., E-mail: sundrarajan@yahoo.com [Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi-3, Tamil Nadu (India)

    2016-05-15

    Highlights: • Fluorine based ionic liquid was highly influenced the morphological structure of nanocomposites. • These composites has been motivated controlled release of silver nanoparticles for uniform antibacterial activity. • These material has given excellent antibacterial biofilm activity and favourable cytotoxical behavior on the human osteosarcoma (MG-63) cells. • These material has been highly suitable for bone substitute appliactions. - Abstract: A novel green route has approached for the synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin composite by the assistance of fluorine-based ionic liquid. The selected [BMIM]BF{sub 4} ionic liquid for this work plays a dual role as fluoride source and templating agent. It helps to improve the crystalline structures and the shape of the composites. The crystallinity, surface morphology, topographical studies of the synthesized composite were validated. The XRD results of the composite show typical Ag reflection peaks at 38.1°, 44.2° and 63.4°. The ionic liquid assisted composite displayed the hexagonal shaped HA particles, which are surrounded by spherical nano-Ag particles and these particles are uniformly dispersed in the β-cyclodextrin matrix in both horizontal and cross sections from surface morphology observations. The Ionic liquid assisted silver doped fluor-hydroxyapatite/β-cyclodextrin composite exhibited very good antibacterial activities against Escherichia coli, Salmonella typhi, Klebsiella pneumonia and Serratia liquefaciens pathogens. The antibacterial proficiencies were established using Confocal Laser Scanning Microscopic developed biofilms images and bacterial growth curve analysis. The cytotoxicity results of the ionic liquid assisted composite analyzed by cell proliferation in vitro studies using human osteosarcoma cell line (MG-63) and this study has shown excellent biocompatibility.

  9. Facile green synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin nanocomposite in the dual acting fluorine-containing ionic liquid medium for bone substitute applications

    International Nuclear Information System (INIS)

    Jegatheeswaran, S.; Selvam, S.; Sri Ramkumar, V.; Sundrarajan, M.

    2016-01-01

    Highlights: • Fluorine based ionic liquid was highly influenced the morphological structure of nanocomposites. • These composites has been motivated controlled release of silver nanoparticles for uniform antibacterial activity. • These material has given excellent antibacterial biofilm activity and favourable cytotoxical behavior on the human osteosarcoma (MG-63) cells. • These material has been highly suitable for bone substitute appliactions. - Abstract: A novel green route has approached for the synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin composite by the assistance of fluorine-based ionic liquid. The selected [BMIM]BF_4 ionic liquid for this work plays a dual role as fluoride source and templating agent. It helps to improve the crystalline structures and the shape of the composites. The crystallinity, surface morphology, topographical studies of the synthesized composite were validated. The XRD results of the composite show typical Ag reflection peaks at 38.1°, 44.2° and 63.4°. The ionic liquid assisted composite displayed the hexagonal shaped HA particles, which are surrounded by spherical nano-Ag particles and these particles are uniformly dispersed in the β-cyclodextrin matrix in both horizontal and cross sections from surface morphology observations. The Ionic liquid assisted silver doped fluor-hydroxyapatite/β-cyclodextrin composite exhibited very good antibacterial activities against Escherichia coli, Salmonella typhi, Klebsiella pneumonia and Serratia liquefaciens pathogens. The antibacterial proficiencies were established using Confocal Laser Scanning Microscopic developed biofilms images and bacterial growth curve analysis. The cytotoxicity results of the ionic liquid assisted composite analyzed by cell proliferation in vitro studies using human osteosarcoma cell line (MG-63) and this study has shown excellent biocompatibility.

  10. Synthesis and characterization of functional magnetic nanocomposites

    Science.gov (United States)

    Gass, J.; Sanders, J.; Srinath, S.; Srikanth, H.

    2006-03-01

    Magnetic nanoparticles and carbon nanotubes have been excellent functional materials that could be dispersed in polymer matrices for various applications. However, uniform dispersion of particles in polymers without agglomeration is quite challenging. We have fabricated PMMA/polypyrrole bilayer structures embedded with Fe3O4 magnetite nanoparticles synthesized using wet chemical synthesis. Agglomeration-free dispersion of nanoparticles was achieved by coating the particles with surfactants and by dissolving both the particles and PMMA in chlorobenzene. Structural characterization was done using XRD and TEM. Magnetic properties of the bilayer structures indicated superparamagnetic behavior that is desirable for RF applications as the magnetic losses are reduced. Our polymer nanocomposite bilayer films with conducting polymer coatings are potential candidates for tunable RF applications with integrated EMI suppression. We will also report on our studies of pumped ferrofluids flowing past carbon nanotubes that are arranged in microchannel arrays. Magnetization under various flow conditions is investigated and correlated with the hydrodynamic properties. This scheme provides a novel method of energy conversion and storage using nanocomposite materials.

  11. Development and synthesis nanocompositions DLC coatings with orientation effect

    International Nuclear Information System (INIS)

    Levchenko, V.A.; Novoselova, N.V.; Matveenko, V.N.

    2008-01-01

    On the basis of volume modelling and a detailed experimental research of physical and chemical properties nanocompositions DLC with one-dimensional highly orientationally the carbon structure on interphase border of section with lubricant as models tribological knot, proves typical models of synthesis new nanocompositions the DLC possessing high tribological properties (by high wear resistance, low of a friction, etc.). The influence mechanism orientation properties of a surface of the synthesized coatings on molecular in a boundary lubricant layer is investigated. On basis tribological experimental batch tests nanocompositions the carbon coatings possessing orientation effect, the synthesis mechanism highly orientationally DLC coatings with optimum tribological properties is developed.

  12. Facile synthesis of silicon carbide-titanium dioxide semiconducting nanocomposite using pulsed laser ablation technique and its performance in photovoltaic dye sensitized solar cell and photocatalytic water purification

    Energy Technology Data Exchange (ETDEWEB)

    Gondal, M.A., E-mail: magondal@kfupm.edu.sa [Laser Research Group, Physics Department & Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Ilyas, A.M. [Laser Research Group, Physics Department & Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Baig, Umair [Laser Research Group, Physics Department & Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Center of Excellence for Scientific Research Collaboration with MIT, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2016-08-15

    Highlights: • SiC–TiO{sub 2} semiconducting nanocomposites synthesized by nanosecond PLAL technique. • Synthesized nanocomposites were morphologically and optically characterized. • Nanocomposites were applied for the photocatalytic degradation of toxic organic dye. • Photovoltaic performance was investigated in dye sensitized solar cell. - Abstract: Separation of photo-generated charge carriers (electron and holes) is a major approach to improve the photovoltaic and photocatalytic performance of metal oxide semiconductors. For harsh environment like high temperature applications, ceramic like silicon carbide is very prominent. In this work, 10%, 20% and 40% by weight of pre-oxidized silicon carbide was coupled with titanium dioxide (TiO{sub 2}) to form nanocomposite semiconductor via elegant pulsed laser ablation in liquid technique using second harmonic 532 nm wavelength of neodymium-doped yttrium aluminium garnet (Nd-YAG) laser. In addition, the effect of silicon carbide concentration on the performance of silicon carbide-titanium dioxide nanocomposite as photo-anode in dye sensitized solar cell and as photocatalyst in photodegradation of methyl orange dye in water was also studied. The result obtained shows that photo-conversion efficiency of the dye sensitized solar cell was improved from 0.6% to 1.65% and the percentage of methyl orange dye removed was enhanced from 22% to 77% at 24 min under ultraviolet–visible solar spectrum in the nanocomposite with 10% weight of silicon carbide. This remarkable performance enhancement could be due to the improvement in electron transfer phenomenon by the presence of silicon carbide on titanium dioxide.

  13. Facile synthesis and characterization of NiO-SnO2 ceramic nanocomposite and its unique performance in organic pollutants degradation

    Science.gov (United States)

    Nejati Moghadam, Laya; Salavati-Niasari, Masoud

    2017-10-01

    The ceramic nanocomposite of NiO-SnO2 has been known as a professional gas sensor in many fields. In this work, this nanocomposite was prepared with a simple in-situ method successfully. NiO-SnO2 was characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), and transmission electron microscopy (TEM). The obtained NiO-SnO2 is crystalline with a cubic structure. The photoluminescence measurement reveals one emission peak at about 3.18 eV at room temperature. In addition, this compound shows a good performance in degradation of organic dyes in a photo-catalytically reaction.

  14. Facile synthesis of core–shell structured PANI-Co{sub 3}O{sub 4} nanocomposites with superior electrochemical performance in supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Zhenyin [Key Laboratory of Instrumentation and Dynamic Measurement of Ministry of Education, North University of China, Taiyuan, Shanxi 030051 (China); Gao, Libo [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong SAR, Kowloon 999077 (Hong Kong); Zhang, Qiang [Key Laboratory of Instrumentation and Dynamic Measurement of Ministry of Education, North University of China, Taiyuan, Shanxi 030051 (China); Xu, Hongyan [School of Materials Science and Engineering, North University of China, Taiyuan, Shanxi 030051 (China); Cui, Danfeng; Zhang, Zengxing [Key Laboratory of Instrumentation and Dynamic Measurement of Ministry of Education, North University of China, Taiyuan, Shanxi 030051 (China); Tsoukalas, Dimitris [Department of Applied Physics, National Technical University of Athens, Zografou GR-15780 (Greece); Tang, Jun; Yan, Shubin [Key Laboratory of Instrumentation and Dynamic Measurement of Ministry of Education, North University of China, Taiyuan, Shanxi 030051 (China); Xue, Chenyang, E-mail: xuechenyang@nuc.edu.cn [Key Laboratory of Instrumentation and Dynamic Measurement of Ministry of Education, North University of China, Taiyuan, Shanxi 030051 (China)

    2016-01-15

    Graphical abstract: - Highlights: • PANI-Co{sub 3}O{sub 4} is synthesized by carbon-assisted and in situ polymerization methods. • PANI coating improves the properties of Co{sub 3}O{sub 4} affecting electrochemical performance. • The nanocomposites exhibit a high specific capacitance of 1184 F g{sup −1} at 1.25 A g{sup −1}. - Abstract: Core–shell structured PANI-Co{sub 3}O{sub 4} nanocomposites for supercapacitor applications were synthesized by combination of carbon-assisted method and in situ polymerization method. The crystalline structure, optical band gap, morphology, and hydrophilic property, as the major factors affecting the performances of supercapacitors, were investigated by X-ray diffraction (XRD), UV–vis spectrophotometry (UV–vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and water contact angle (WCA). The core–shell structured PANI-Co{sub 3}O{sub 4} nanocomposites are characterized by amorphous PANI, small bandgaps, large surface area and favorable hydrophilicity, which indicates the superior electrochemical performances of the nanocomposites as electrode material for supercapacitors. Cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) measurements were conducted in 6 M KOH aqueous solution to evaluate the electrochemical performances. The results shows that core–shell structured PANI-Co{sub 3}O{sub 4} nanocomposites exhibit a high specific capacitance of 1184 F g{sup −1} at 1.25 A g{sup −1}, excellent cycling stability of a capacitance retention of 84.9% after 1000 galvanostatic charge/discharge cycles, good electrical conductivity and ion diffusion behavior.

  15. Facile synthesis of multifunctional attapulgite/Fe{sub 3}O{sub 4}/polyaniline nanocomposites for magnetic dispersive solid phase extraction of benzoylurea insecticides in environmental water samples

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoling; Qiao, Kexin; Ye, Yiren; Yang, Miyi; Li, Jing; Gao, Haixiang; Zhang, Sanbing; Zhou, Wenfeng; Lu, Runhua, E-mail: rhlu@cau.edu.cn

    2016-08-31

    In this study, the superparamagnetic attapulgite/Fe{sub 3}O{sub 4}/polyaniline (ATP/Fe{sub 3}O{sub 4}/PANI) nanocomposites were successfully synthesized by a one-pot method. Fe (III) was applied as both the oxidant for the oxidative polymerization of aniline and the single iron source of Fe{sub 3}O{sub 4} formed by the redox reaction between aniline and Fe (III). The ATP/Fe{sub 3}O{sub 4}/PANI was used as sorbent for magnetic dispersive solid phase extraction (MDSPE) of benzoylurea insecticides (BUs) in environmental water samples. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X Ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry. Various experimental parameters affecting the ATP/Fe{sub 3}O{sub 4}/PANI-based MDSPE procedure, including the composition of the nanocomposite sorbents, amount of ATP/Fe{sub 3}O{sub 4}/PANI nanocomposites, vortex time, pH, and desorption conditions were investigated. Under the optimal conditions, a good linearity was observed for all target analytes, with correlation coefficients (r{sup 2}) ranging from 0.9985 to 0.9997; the limits of detection (LOD) were in the range of 0.02–0.43 μg L{sup −1}, and the recoveries of analytes using the proposed method ranged between 77.37% and 103.69%. The sorbents exhibited an excellent reproducibility in the range of 1.52–5.27% in extracting the five target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.78–6.86% and 1.66–8.41%, respectively. Finally, the proposed ATP/Fe{sub 3}O{sub 4}/PANI-based MDSPE method was successfully applied to analyze river water samples by rapid preconcentration of BUs. - Highlights: • A novel superparamagnetic ATP/Fe{sub 3}O{sub 4}/PANI nanocomposite was first introduced in MDSPE. • ATP/Fe{sub 3}O{sub 4}/PANI nanocomposites exhibited fast adsorption and desorption

  16. Facile synthesis of multifunctional attapulgite/Fe3O4/polyaniline nanocomposites for magnetic dispersive solid phase extraction of benzoylurea insecticides in environmental water samples

    International Nuclear Information System (INIS)

    Yang, Xiaoling; Qiao, Kexin; Ye, Yiren; Yang, Miyi; Li, Jing; Gao, Haixiang; Zhang, Sanbing; Zhou, Wenfeng; Lu, Runhua

    2016-01-01

    In this study, the superparamagnetic attapulgite/Fe 3 O 4 /polyaniline (ATP/Fe 3 O 4 /PANI) nanocomposites were successfully synthesized by a one-pot method. Fe (III) was applied as both the oxidant for the oxidative polymerization of aniline and the single iron source of Fe 3 O 4 formed by the redox reaction between aniline and Fe (III). The ATP/Fe 3 O 4 /PANI was used as sorbent for magnetic dispersive solid phase extraction (MDSPE) of benzoylurea insecticides (BUs) in environmental water samples. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X Ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry. Various experimental parameters affecting the ATP/Fe 3 O 4 /PANI-based MDSPE procedure, including the composition of the nanocomposite sorbents, amount of ATP/Fe 3 O 4 /PANI nanocomposites, vortex time, pH, and desorption conditions were investigated. Under the optimal conditions, a good linearity was observed for all target analytes, with correlation coefficients (r 2 ) ranging from 0.9985 to 0.9997; the limits of detection (LOD) were in the range of 0.02–0.43 μg L −1 , and the recoveries of analytes using the proposed method ranged between 77.37% and 103.69%. The sorbents exhibited an excellent reproducibility in the range of 1.52–5.27% in extracting the five target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.78–6.86% and 1.66–8.41%, respectively. Finally, the proposed ATP/Fe 3 O 4 /PANI-based MDSPE method was successfully applied to analyze river water samples by rapid preconcentration of BUs. - Highlights: • A novel superparamagnetic ATP/Fe 3 O 4 /PANI nanocomposite was first introduced in MDSPE. • ATP/Fe 3 O 4 /PANI nanocomposites exhibited fast adsorption and desorption kinetics. • An excellent sorbent-to-sorbent reproducibility was demonstrated in the

  17. Synthesis and characterization of graphene quantum dots/cobalt ferrite nanocomposite

    Science.gov (United States)

    Ramachandran, Shilpa; Sathishkumar, M.; Kothurkar, Nikhil K.; Senthilkumar, R.

    2018-02-01

    A facile method has been developed for the synthesis of a graphene quantum dots/cobalt ferrite nanocomposite. Graphene quantum dots (GQDs) were synthesized by a simple bottom-up method using citric acid, followed by the co-precipitation of cobalt ferrite nanoparticles on the graphene quantum dots. The morphology, structural analysis, optical properties, magnetic properties were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis absorption spectroscopy, fluorescence spectroscopy, vibrating sample magnetometry (VSM) measurements. The synthesized nanocomposite showed good fluorescence and superparamagnetic properties, which are important for biomedical applications.

  18. Green and facile synthesis of graphene nanosheets/K{sub 3}PW{sub 12}O{sub 40} nanocomposites with enhanced photocatalytic activities

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hongxun, E-mail: yhongxun@126.com [School of Environmental & Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian, Fuzhou 350002 (China); Liu, Xiaoyan; Sun, Shengnan; Nie, Yu; Wu, Huipeng; Yang, Tongyi; Zheng, Shaojun [School of Environmental & Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Lin, Shengling, E-mail: linshl5757@sina.com [School of Environmental & Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China)

    2016-06-15

    Highlights: • A new graphene/K{sub 3}PW{sub 12}O{sub 40} (GPW) composite was synthesized via photoreduction method. • Graphene in the GPW could reduce the recombination of electron-hole pairs. • Graphene in the GPW could increase adsorptive property. • GPW hybrid shows an enhancement photocatalytic activity. - Abstract: K{sub 3}PW{sub 12}O{sub 40} is a promising polyoxometalate photocatalyst for the removal of organic pollutants from water. However, two main disadvantages of poor adsorptive performance and high recombination rate of photogenerated electron-hole pair hinder its practical applications. In this paper, a new graphene nanosheets/K{sub 3}PW{sub 12}O{sub 40} nanocomposite has been synthesized via a green photoreduction strategy, being low-cost and scalable production. Characterizations show that K{sub 3}PW{sub 12}O{sub 40} nanoparticles with 60 nm or so have been successfully deposited on the graphene nanosheets. As a kind of photocatalyst, the binary graphene nanosheets/K{sub 3}PW{sub 12}O{sub 40} nanocomposite displays improved photocatalytic activity compared to pure K{sub 3}PW{sub 12}O{sub 40}. This improvement is ascribed to the introduction of graphene nanosheets in the nanocomposite, which could increase adsorptive property and reduce the recombination of electron-hole pairs.

  19. Synthesis and Characterization of Hydroxyapatite/Fullerenol Nanocomposites.

    Science.gov (United States)

    Djordjevic, Aleksandar; Ignjatovic, Nenad; Seke, Mariana; Jovic, Danica; Uskokovic, Dragan; Rakocevic, Zlatko

    2015-02-01

    Fullerenols are polyhydroxylated, water soluble derivatives of fullerene C60, with potential application in medicine as diagnostic agents, antioxidants or nano drug carriers. This paper describes synthesis and physical characterization of a new nanocomposite hydroxyapatite/fullerenol. Surface of the nanocomposite hydroxyapatite/fullerenol is inhomogeneous with the diameter of the particles in the range from 100 nm to 350 nm. The ζ potential of this nanocomposite is ten times lower when compared to hydroxyapatite. Surface phosphate groups of hydroxyapatite are prone to forming hydrogen bonds, when in close contact with hydroxyl groups, which could lead to formation of hydrogen bonds between hydroxyapatite and hydroxyl groups of fullerenol. The surface of hydroxyapatite particles (-2.5 mV) was modified by fullerenol particles, as confirmed by the obtained ζ potential value of the nanocomposite biomaterial hydroxyapatite/fullerenol (-25.0 mV). Keywords: Hydroxyapatite, Fullerenol, Nanocomposite, Surface Analysis.

  20. Rapid synthesis of flexible conductive polymer nanocomposite films

    International Nuclear Information System (INIS)

    Blattmann, C O; Sotiriou, G A; Pratsinis, S E

    2015-01-01

    Polymer nanocomposite films with nanoparticle-specific properties are sought out in novel functional materials and miniaturized devices for electronic and biomedical applications. Sensors, capacitors, actuators, displays, circuit boards, solar cells, electromagnetic shields and medical electrodes rely on flexible, electrically conductive layers or films. Scalable synthesis of such nanocomposite films, however, remains a challenge. Here, flame aerosol deposition of metallic nanosliver onto bare or polymer-coated glass substrates followed by polymer spin-coating on them leads to rapid synthesis of flexible, free-standing, electrically conductive nanocomposite films. Their electrical conductivity is determined during their preparation and depends on substrate composition and nanosilver deposition duration. Accordingly, thin (<500 nm) and flexible nanocomposite films are made having conductivity equivalent to metals (e.g. 5  × 10 4 S cm −1 ), even during repetitive bending. (paper)

  1. Synthesis, thermal properties and applications of polymer-clay nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Meneghetti, Paulo [Chemical Engineering Department, Case Western Reserve University, 10900 Euclid Ave. Cleveland, OH 44106 (United States); Qutubuddin, Syed [Chemical Engineering Department, Case Western Reserve University, 10900 Euclid Ave. Cleveland, OH 44106 (United States)]. E-mail: sxq@case.edu

    2006-03-15

    Polymer-clay nanocomposites constitute a new class of materials in which the polymer matrix is reinforced by uniformly dispersed inorganic particles (usually 10 wt.% or less) having at least one dimension in the nanometer scale. Nanocomposites exhibit improved properties when compared to pure polymer or conventional composites, such as enhanced mechanical and thermal properties, reduced gas permeability, and improved chemical stability. In this work, the synthesis of poly(methyl methacrylate) (PMMA)/clay nanocomposites is described via two methods: in situ and emulsion polymerization. The in situ technique follows a two-step process: ion-exchange of the clay to make it hydrophobic, and polymerization after dispersing the functionalized clay in the monomer. The emulsion technique combines the two steps of the in situ method into one by conducting ion-exchange and polymerization in an aqueous medium in the same reactor. The clay (montmorillonite, MMT) is functionalized with a zwitterionic surfactant, octadecyl-dimethyl betaine (C18DMB). Partially exfoliated nanocomposite, observed by transmission electron microscopy (TEM), was obtained by emulsion polymerization with 10 wt.% clay. Glass transition temperature (T {sub g}) of this nanocomposite was 18 deg. C higher than pure PMMA. With the same clay content, in situ polymerization produced intercalated nanocomposite with T {sub g} 10 deg. C lower than the emulsion nanocomposite. The storage modulus of partially exfoliated nanocomposite was superior to the intercalated structure and to the pure polymer. Using nanocomposite technology, novel PMMA nanocomposite gel electrolytes were synthesized exhibiting improved ionic conductivity and stable lithium interfacial resistance. Nanocomposites can also be used for gas storage and packaging applications as demonstrated by high barrier polymer-clay films.

  2. Synthesis, thermal properties and applications of polymer-clay nanocomposites

    International Nuclear Information System (INIS)

    Meneghetti, Paulo; Qutubuddin, Syed

    2006-01-01

    Polymer-clay nanocomposites constitute a new class of materials in which the polymer matrix is reinforced by uniformly dispersed inorganic particles (usually 10 wt.% or less) having at least one dimension in the nanometer scale. Nanocomposites exhibit improved properties when compared to pure polymer or conventional composites, such as enhanced mechanical and thermal properties, reduced gas permeability, and improved chemical stability. In this work, the synthesis of poly(methyl methacrylate) (PMMA)/clay nanocomposites is described via two methods: in situ and emulsion polymerization. The in situ technique follows a two-step process: ion-exchange of the clay to make it hydrophobic, and polymerization after dispersing the functionalized clay in the monomer. The emulsion technique combines the two steps of the in situ method into one by conducting ion-exchange and polymerization in an aqueous medium in the same reactor. The clay (montmorillonite, MMT) is functionalized with a zwitterionic surfactant, octadecyl-dimethyl betaine (C18DMB). Partially exfoliated nanocomposite, observed by transmission electron microscopy (TEM), was obtained by emulsion polymerization with 10 wt.% clay. Glass transition temperature (T g ) of this nanocomposite was 18 deg. C higher than pure PMMA. With the same clay content, in situ polymerization produced intercalated nanocomposite with T g 10 deg. C lower than the emulsion nanocomposite. The storage modulus of partially exfoliated nanocomposite was superior to the intercalated structure and to the pure polymer. Using nanocomposite technology, novel PMMA nanocomposite gel electrolytes were synthesized exhibiting improved ionic conductivity and stable lithium interfacial resistance. Nanocomposites can also be used for gas storage and packaging applications as demonstrated by high barrier polymer-clay films

  3. Facile synthesis of a nitrogen-doped graphene flower-like MnO2 nanocomposite and its application in supercapacitors

    Science.gov (United States)

    Dong, Jinyang; Lu, Gang; Wu, Fan; Xu, Chenxi; Kang, Xiaohong; Cheng, Zhiming

    2018-01-01

    A flower-like MnO2 nanocomposite embedded in nitrogen-doped graphene (NG-MnO2) is fabricated by a hydrothermal method. It is a mesoporous nanomaterial with a pore size of approximately 0.765 cm3 g-1 and specific surface area of 201.8 m2 g-1. NG-MnO2 exhibits a superior average specific capacitance of 220 F g-1 at 0.5 A g-1 and a preferable capacitance of 189.1 F g-1, even at 10 A g-1. After 1000 cycles, over 98.3% of the original specific capacitance retention of the NG-MnO2 electrode is maintained, and it can even activate a red light emitting diode (LED) after being charged, which indicates that it has excellent cycling stability as an electrode material. This prominent electrochemical performance is primarily attributed to the nitrogen doping and mesoporous structures of NG-MnO2, which can be attributed to its numerous electroactive sites as well as faster ion and electron transfer for redox reactions than general graphene-MnO2 nanocomposites (G-MnO2).

  4. An Innovative Electrolysis Approach for the Synthesis of Metal Matrix Bulk Nanocomposites: A Case Study on Copper-Niobium System

    Science.gov (United States)

    Shokrvash, Hussein; Rad, Rahim Yazdani; Massoudi, Abouzar

    2018-04-01

    Design and synthesis of a prototype Cu-Nb nanocomposite are presented. Oxygen-free Cu-Nb nanocomposites were prepared using an electrolysis facility with special emphasis on the cathodic deoxidation of Cu and nanometric Nb2O5 blends in a molten NaCl-CaCl2 electrolyte. The as-prepared nanocomposites were characterized by X-ray diffraction and energy-dispersive X-ray spectroscopy. The elemental analysis of the Cu matrix and Nb phase revealed the high solubility of Nb in the Cu structure (0.85 at. pct) and Cu in the Nb structure (10.59 at. pct) over short synthesis times (4-5 hours). Furthermore, precise analysis using field emission scanning electron microscopy and transmission electron microscopy confirmed the unique structure and nanocomposite morphology of the Cu-Nb nanocomposite. The successful synthesis of Cu-Nb nanocomposites offers a new conceptual and empirical outlook on the generation of bulk nanostructures of immiscible bimetals using electro-synthesis.

  5. Amphibious fluorescent carbon dots: one-step green synthesis and application for light-emitting polymer nanocomposites.

    Science.gov (United States)

    Zhou, Li; He, Benzhao; Huang, Jiachang

    2013-09-21

    A facile and green approach for the synthesis of amphibious fluorescent carbon dots (CDs) from natural polysaccharide is reported. Light-emitting polymer nanocomposites with excellent optical performance can be easily prepared by incorporation of the amphibious CDs into the polymer matrix.

  6. Polymer nanotube nanocomposites: synthesis, properties, and applications

    National Research Council Canada - National Science Library

    Mittal, Vikas

    2010-01-01

    ... insights for the use of technologies for polymer nanocomposites for commercial application, and features chapters from the most experienced researches in the field"-- "The purpose of this edited book...

  7. Synthesis of polyaniline/ZrO 2 nanocomposites and their ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 3. Synthesis of polyaniline/ZrO 2 nanocomposites and their performance in AC conductivity and electrochemical supercapacitance. B P PRASANNA D N AVADHANI H B MURALIDHARA K CHAITRA VINNY ROSE THOMAS M REVANASIDDAPPA N ...

  8. Synthesis of PDLLA/PLLA-bentonite nanocomposite through sonication

    International Nuclear Information System (INIS)

    Sitompul, Johnner; Setyawan, Daru; Kim, Daniel Young Joon; Lee, Hyung Woo

    2016-01-01

    This paper concerns the synthesis of poly(D,L-lactic acid)/poly(L-lactic acid) bentonite nanocomposites. Poly (D,L-lactic acid) (PDLLA) was synthesized using lactic acid through the ZnO-catalyzed direct polycondensation method at vacuum pressure and poly(L-lactic acid) (PLLA) was synthesized with L-lactide by ring-opening polymerization method. The PDLLA/PLLA-bentonite nanocomposite films were synthesized using the solvent casting method. The nanoclay, bentonite, was prepared using the solution-intercalation method by dissolving the nanoparticles into chloroform before sonication. In this study, PDLLA/PLLA-bentonite nanocomposite films were produced using variable amounts of nanoclay and sonication times during the mixing of PDLLA/PLLA and bentonite. The properties of the PDLLA/PLLA nanocomposites were then characterized using the X-ray Diffraction (XRD), Universal Testing Machine (UTM), Water Vapor Permeability (WVP) tests, and the enzymatic biodegradability test. The XRD test was used to measure the intercalation of nanoclay layers in the PDLLA/PLLA matrix and the PDLLA/PLLA-bentonite intercalated nanocomposite films. It was found through these various tests that adding bentonite to the PDLLA/PLLA increases tensile strength to 56.76 MP. Furthermore, the biodegradability increases as well as the barrier properties of the polymers The different sonication time used during the mixing of the polymer solution with bentonite also affected the properties of the PDLLA/PLLA-bentonite nanocomposite films.

  9. Synthesis of PDLLA/PLLA-bentonite nanocomposite through sonication

    Energy Technology Data Exchange (ETDEWEB)

    Sitompul, Johnner, E-mail: sitompul@che.itb.ac.id; Setyawan, Daru, E-mail: daru.setyawan@gmail.com; Kim, Daniel Young Joon, E-mail: daniel.kim12321@gmail.com [Department of Chemical Engineering, Faculty of Industrial Technology, Institute of Technology Bandung Jl. Ganesha 10, Bandung, West Java, 40132 (Indonesia); Lee, Hyung Woo, E-mail: leehw@che.itb.ac.id [Department of Chemical Engineering, Faculty of Industrial Technology, Institute of Technology Bandung Jl. Ganesha 10, Bandung, West Java, 40132 (Indonesia); Research and Business Foundation, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi, 440-746 (Korea, Republic of)

    2016-04-19

    This paper concerns the synthesis of poly(D,L-lactic acid)/poly(L-lactic acid) bentonite nanocomposites. Poly (D,L-lactic acid) (PDLLA) was synthesized using lactic acid through the ZnO-catalyzed direct polycondensation method at vacuum pressure and poly(L-lactic acid) (PLLA) was synthesized with L-lactide by ring-opening polymerization method. The PDLLA/PLLA-bentonite nanocomposite films were synthesized using the solvent casting method. The nanoclay, bentonite, was prepared using the solution-intercalation method by dissolving the nanoparticles into chloroform before sonication. In this study, PDLLA/PLLA-bentonite nanocomposite films were produced using variable amounts of nanoclay and sonication times during the mixing of PDLLA/PLLA and bentonite. The properties of the PDLLA/PLLA nanocomposites were then characterized using the X-ray Diffraction (XRD), Universal Testing Machine (UTM), Water Vapor Permeability (WVP) tests, and the enzymatic biodegradability test. The XRD test was used to measure the intercalation of nanoclay layers in the PDLLA/PLLA matrix and the PDLLA/PLLA-bentonite intercalated nanocomposite films. It was found through these various tests that adding bentonite to the PDLLA/PLLA increases tensile strength to 56.76 MP. Furthermore, the biodegradability increases as well as the barrier properties of the polymers The different sonication time used during the mixing of the polymer solution with bentonite also affected the properties of the PDLLA/PLLA-bentonite nanocomposite films.

  10. Facile fabrication of novel silver-polypyrrole-multiwall carbon nanotubes nanocomposite for replacement of platinum in dye-sensitized solar cell

    OpenAIRE

    Shaista Rafique; Rehana Sharif; Imran Rashid; Sheeba Ghani

    2016-01-01

    This paper demonstrates the facile synthesis of high performance silver-polypyrrole-multiwall carbon nanotubes (Ag-PPy-FMWCNTS) nanocomposites via electrodeposition method on stainless steel substrate and its application as a low cost counter electrode (CE) for the precious platinum (Pt) free DSSC. The nanocomposites were characterized by variety of techniques such as Fourier transforms infrared (FTIR), X-ray diffraction, Scanning electron microscope (SEM), cyclic voltammetry (CV) and Four pr...

  11. Facile synthesis of flake-like TiO{sub 2}/C nano-composites for photocatalytic H{sub 2} evolution under visible-light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Baolin; Zhou, Juan; Liang, Xiaoyu; Song, Kainan; Su, Xintai, E-mail: suxintai827@163.com

    2017-01-15

    Highlights: • TiO{sub 2}/C nano-flakes were prepared by a facile phase-transfer strategy combined with salt-template calcination method. • The sub–10 nm of TiO{sub 2} NPs were uniformly dispersed on the carbon flakes. • The TiO{sub 2}/C nano-flakes showed a superior visible-light photocatalytic activity for H{sub 2} production. - Abstract: The production of H{sub 2} by photocatalytic water splitting has become a promising approach for clean, economical, and renewable evolution of H{sub 2} by using solar energy. In spite of tremendous efforts, the present challenge for materials scientists is to build a highly active photocatalytic system with high efficiency and low cost. Here we report a facile method for the preparation of TiO{sub 2}/C nano-flakes, which was used as an efficient visible-light photocatalyst for H{sub 2} evolution. This composite material was prepared by using a phase-transfer strategy combined with salt-template calcination treatment. The results showed that anatase TiO{sub 2} nanoparticles with the diameter of ∼10 nm were uniformly dispersed on the carbon nano-flakes. In addition, the samples prepared at 600 °C (denoted as T600) endowed a larger surface area of 196 m{sup 2} g{sup −1} and higher light absorption, resulting in enhanced photocatalytic activity. Further, the T600 product reached a high H{sub 2} production rate of 57.2 μmol h{sup −1} under visible-light irradiation. This unusual photocatalytic activity arose from the positive synergetic effect between the TiO{sub 2} and carbon in this hybrid catalyst. This work highlights the potential of TiO{sub 2}/C nano-flakes in the field of photocatalytic H{sub 2} evolution under visible-light irradiation.

  12. Synthesis of copper polyacrylate nanocomposites by gamma irradiation

    International Nuclear Information System (INIS)

    Casalme, Loida Olores

    2005-04-01

    This research involves the synthesis of copper nanoparticles with controlled size by the application of gamma radiation with varying polyacrylic acid (PAA) and CuSO 4 concentration. An alternative and convenient method was done which employs Co 60 irradiation of solutions of copper salt and PAA with irradiation dose of 1.6, 3.6, 6.4, and 9.2 MRad. The effect of polymer and copper sulfate's initial concentrations as well as the effect of the presence of alcohol as radical scavenger and the presence of ethylenediaminetetraacetic acid as stabilizer were evaluated. Characterization of nanocomposite properties such as plasmon resonance band, fluorescence, and particle morphology and size were determined. Layer-by-layer assembly of Cu-PAA nanocomposites and polydiallyl dimethyl ammonium chloride (PDDA) was also constructed. Stability of the synthesized copper-PAA nanocomposites in terms of the disappearance of plasmon band with time was evaluated. (Author)

  13. Facile hydrothermal synthesis of Fe3O4@cellulose aerogel nanocomposite and its application in Fenton-like degradation of Rhodamine B.

    Science.gov (United States)

    Jiao, Yue; Wan, Caichao; Bao, Wenhui; Gao, He; Liang, Daxin; Li, Jian

    2018-06-01

    A magnetic cellulose aerogel-supported Fe 3 O 4 nanoparticles composite was designed as a highly efficient and eco-friendly catalyst for Fenton-like degradation of Rhodamine B (RhB). The composite (coded as Fe 3 O 4 @CA) was formed by embedding well-dispersed Fe 3 O 4 nanoparticles into the 3D structure of cellulose aerogels by virtue of a facile and cheap hydrothermal method. Comparative studies indicate that the RhB decolorization ratio is much higher in co-presence of Fe 3 O 4 and H 2 O 2 than that in presence of Fe 3 O 4 or H 2 O 2 only, revealing that the Fe 3 O 4 @CA-catalyzed Fenton-like reaction governed the RhB decolorization process. It was also found that almost 100% RhB removal was achieved in the Fenton-like system. Moreover, the composite exhibited higher catalytic activity than that of the individual Fe 3 O 4 particles. In addition, the Fe 3 O 4 @CA catalyst retained ∼97% of its ability to degrade RhB after the six successive degradation experiments, suggesting its excellent reusability. All these merits indicate that the green and low-cost catalyst with strong magnetic responsiveness possesses good potential for H 2 O 2 -driven Fenton-like treatment of organic dyestuff wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Synthesis of PbS/poly (vinyl-pyrrolidone) nanocomposite

    International Nuclear Information System (INIS)

    Patel, Jayesh D.; Chaudhuri, Tapas K.

    2009-01-01

    A simple solution growth method for synthesis of nanocomposite of PbS nanoparticles in poly(vinyl-pyrrolidone) (PVP) polymer is described. The nanocomposite is prepared from methanolic solution of lead acetate (PbAc), thiourea (TU) and PVP at room temperature (∼27 deg. C). Optical absorption spectrum of PbS/PVP nanocomposite solution shows strong absorption from 300 to 650 nm with significant bands at 400 and 590 nm which is characteristic of nanoscale PbS. Spin-coated nanocomposite films on glass have an absorption edge at ∼650 nm with band gap of 2.55 eV. Fourier transform infrared (FTIR) spectroscopy of PbS/PVP nanocomposite and PVP shows strong chemical bond between PbS nanoparticles and host PVP polymer. The transmission electron microscope (TEM) images reveal that 5-10 nm PbS particles are evenly embedded in PVP polymer. The formation of PbS is confirmed by selective area electron diffraction (SAED) of a typical nanoparticle.

  15. Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms

    International Nuclear Information System (INIS)

    Nunes, D.; Vilarigues, M.; Correia, J.B.; Carvalho, P.A.

    2012-01-01

    The present work investigates Ni–nanodiamond and Ni–graphite composites produced by mechanical synthesis and subsequent heat treatments. Processing of nickel–carbon nanocomposites by this powder metallurgy route poses specific challenges, as carbon phases are prone to carbide conversion and amorphization. The processing window for carbide prevention has been established through X-ray diffraction by a systematic variation of the milling parameters. Transmission electron microscopy confirmed the absence of carbide and showed homogeneous particle distributions, as well as intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained largely unaffected by mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. The results on the annealed nanocomposites showed that milling with Ni accelerated graphitization of the carbon phases during heat treatments at 973 and 1073 K in both composites. At the finer scales, the nanocomposites exhibited a remarkable microhardness enhancement (∼70%) compared with pure nanostructured nickel. The Hall–Petch relation and the Orowan–Ashby equation are used to discuss strengthening mechanisms and the load transfer ability to the reinforcing particles.

  16. Gas-phase synthesis of magnetic metal/polymer nanocomposites

    Science.gov (United States)

    Starsich, Fabian H. L.; Hirt, Ann M.; Stark, Wendelin J.; Grass, Robert N.

    2014-12-01

    Highly magnetic metal Co nanoparticles were produced via reducing flame spray pyrolysis, and directly coated with an epoxy polymer in flight. The polymer content in the samples varied between 14 and 56 wt% of nominal content. A homogenous dispersion of Co nanoparticles in the resulting nanocomposites was visualized by electron microscopy. The size and crystallinity of the metallic fillers was not affected by the polymer, as shown by XRD and magnetic hysteresis measurements. The good control of the polymer content in the product nanocomposite was shown by elemental analysis. Further, the successful polymerization in the gas phase was demonstrated by electron microscopy and size measurements. The presented effective, dry and scalable one-step synthesis method for highly magnetic metal nanoparticle/polymer composites presented here may drastically decrease production costs and increase industrial yields.

  17. Synthesis and Applications of Inorganic/Organic-Polymer Nanocomposites

    Science.gov (United States)

    Goyal, Anubha

    This research work focuses on developing new synthesis routes to fabricate polymer nanocomposites tailored towards different applications. A simple, one-step method has been devised for synthesizing free-standing, flexible metal nanoparticle-polydimethylsiloxane films. This process simplifies prevalent methods to synthesize nanocomposites, in that here nanoparticles are created in situ while curing the polymer. This route circumvents the need for pre-synthesized nanoparticles, external reducing agents and stabilizers, thereby significantly reducing processing time and cost. The resulting nanocomposite also demonstrates enhancement in mechanical and antibacterial properties, with other envisaged applications in biomedical devices and catalysis. Applying the same mechanism as that used for the formation of bulk metalsiloxane nanocomposites, metal core-siloxane shell nanoparticles and siloxane nanowires were synthesized, with octadecylsilane as the precursor and in situ formed metal nanoparticles (gold, silver) as the catalyst. This method offers some unique advantages over the previously existing methods. This is a room temperature route which does not require high temperature refluxing or the use of pre-synthesized nanoparticles. Furthermore, this synthesis process gives a control over the shape of resulting nanocomposite structures (1-D wires or 0-D spherical particles). High thermal stability of polydimethylsiloxane (PDMS) makes it viable to alternatively synthesize metal nanoparticles in the polymer matrix by thermal decomposition process. This technique is generic across a range of metals (palladium, iron, nickel) and results in nanoparticles with a very narrow size distribution. Membranes with palladium nanoparticles demonstrate catalytic activity in ethylene hydrogenation reaction. Additionally, a new nanocomposite electrode has been developed for flexible and light-weight Li-ion batteries. Flexible films were prepared by the integration of the poly

  18. Graphene Synthesis & Graphene/Polymer Nanocomposites

    Science.gov (United States)

    Liao, Ken-Hsuan

    We successfully developed a novel, fast, hydrazine-free, high-yield method for producing single-layered graphene. Graphene sheets were formed from graphite oxide by reduction with de-ionized water at 130 ºC. Over 65% of the sheets are single graphene layers. A dehydration reaction of exfoliated graphene oxide was utilized to reduce oxygen and transform C-C bonds from sp3 to sp2. The reduction appears to occur in large uniform interconnected oxygen-free patches so that despite the presence of residual oxygen the sp2 carbon bonds formed on the sheets are sufficient to provide electronic properties comparable to reduced graphene sheets obtained using other methods. Cytotoxicity of aqueous graphene was investigated with Dr. Yu-Shen Lin by measuring mitochondrial activity in adherent human skin fibroblasts using two assays. The methyl-thiazolyl-diphenyl-tetrazolium bromide (MTT) assay, a typical nanotoxicity assay, fails to predict the toxicity of graphene oxide and graphene toxicity because of the spontaneous reduction of MTT by graphene and graphene oxide, resulting in a false positive signal. An appropriate alternate assessment, using the water soluble tetrazolium salt (WST-8) assay, reveals that the compacted graphene sheets are more damaging to mammalian fibroblasts than the less densely packed graphene oxide. Clearly, the toxicity of graphene and graphene oxide depends on the exposure environment (i.e. whether or not aggregation occurs) and mode of interaction with cells (i.e. suspension versus adherent cell types). Ultralow percolation concentration of 0.15 wt% graphene, as determined by surface resistance and modulus, was observed from in situ polymerized thermally reduced graphene (TRG)/ poly-urethane-acrylate (PUA) nanocomposite. A homogeneous dispersion of TRG in PUA was revealed by TEM images. The aspect ratio of dispersed TRG, calculated from percolation concentration and modulus, was found to be equivalent to the reported aspect ratio of single

  19. Ultrasonic-assisted synthesis and magnetic studies of iron oxide/MCM-41 nanocomposite

    International Nuclear Information System (INIS)

    Ursachi, Irina; Vasile, Aurelia; Ianculescu, Adelina; Vasile, Eugeniu; Stancu, Alexandru

    2011-01-01

    Highlights: → A quick and facile route for the synthesis of iron oxide/MCM-41 nanocomposite. → Magnetic nanoparticles were stabilized inside the pores of mesoporous silica MCM-41. → The pore size of MCM-41 dictates the properties of iron oxide nanoparticles. → The procedure provides a narrow size distribution of magnetic nanoparticles. - Abstract: Iron oxide nanoparticles were stabilized within the pores of mesoporous silica MCM-41 amino-functionalized by a sonochemical method. Formation of iron oxide nanoparticles inside the mesoporous channels of amino-functionalized MCM-41 was realized by wet impregnation using iron nitrate, followed by calcinations at 550 deg. C in air. The effect of functionalization level on structural and magnetic properties of obtained nanocomposites was studied. The resulting materials were characterized by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy and selected area electron diffraction (HRTEM and SAED), vibrating sample and superconducting quantum interface magnetometers (VSM and SQUID) and nitrogen adsorption-desorption isotherms measurements. The HRTEM images reveal that the most of the iron oxide nanoparticles were dispersed inside the mesopores of silica matrix and the pore diameter of the amino-functionalized MCM-41 matrix dictates the particle size of iron oxide nanoparticles. The obtained material possesses mesoporous structure and interesting magnetic properties. Saturation magnetization value of magnetic iron oxide nanopatricles stabilized in MCM-41 amino-functionalized by in situ sonochemical synthesis was 1.84 emu g -1 . An important finding is that obtained magnetic nanocomposite materials exhibit enhanced magnetic properties than those of iron oxide/MCM-41 nanocomposite obtained by conventional method. The described method is providing a rather short preparation time and a narrow size distribution of iron oxide nanoparticles.

  20. Plasma Synthesis of Nanoparticles for Nanocomposite Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Peter C. Kong; Alex W. Kawczak

    2008-09-01

    The nanocomposite energy applications for plasma reactor produced nanoparticles are reviewed. Nanoparticles are commonly defined as particles less than 100 nm in diameter. Due to this small size, nanoparticles have a high surface-to-volume ratio. This increases the surface energy compared to the bulk material. The high surface-to-volume ratio and size effects (quantum effects) give nanoparticles distinctive chemical, electronic, optical, magnetic and mechanical properties from those of the bulk material. Nanoparticles synthesis can be grouped into 3 broad approaches. The first one is wet phase synthesis (sol-gel processing), the second is mechanical attrition, and the third is gas-phase synthesis (aerosol). The properties of the final product may differ significantly depending on the fabrication route. Currently, there are no economical large-scale production processes for nanoparticles. This hinders the widespread applications of nanomaterials in products. The Idaho National Laboratory (INL) is engaging in research and development of advanced modular hybrid plasma reactors for low cost production of nanoparticles that is predicted to accelerate application research and enable the formation of technology innovation alliances that will result in the commercial production of nanocomposites for alternative energy production devices such as fuel cells, photovoltaics and electrochemical double layer capacitors.

  1. Nanocrystalline functional materials and nanocomposites synthesis through aerosol routes

    Directory of Open Access Journals (Sweden)

    Milošević Olivera B.

    2003-01-01

    Full Text Available This paper represents the results of the design of functional nanocrystalline powders and nanocomposites using chemical reactions in aerosols. The process involves ultrasonic aerosol formation (mist generators with the resonant frequencies of 800 kHz, 1.7 and 2.5 MHz from precursor salt solutions and control over the aerosol decomposition in a high-temperature tubular flow reactor. During decomposition, the aerosol droplets undergo evaporation/drying, precipitation and thermolysis in a single-step process. Consequently, spherical, solid, agglomerate-free submicronic particles are obtained. The particle morphology, revealed as a composite structure consisting of primary crystallites smaller than 20 nm was analysed by several methods (XRD, DSC/DTA, SEM, TEM and discussed in terms of precursor chemistry and process parameters. Following the initial attempts, a more detailed aspect of nanocrystalline particle synthesis was demonstrated for the case of nanocomposites based on ZnO-MeO (MeO=Bi Cr+, suitable for electronic applications, as well as an yttrium-aluminum base complex system, suitable for phosphorus applications. The results imply that parts of the material structure responsible for different functional behaviour appear through in situ aerosol synthesis by processes of intraparticle agglomeration, reaction and sintering in the last synthesis stage.

  2. Synthesis of polypropylene/graphite nanocomposites by means of in situ polymerization

    International Nuclear Information System (INIS)

    Montagna, Larissa S.; Basso, Nara R.S.

    2009-01-01

    The nanotechnology presents a large field for research and development of new polymeric materials based in nanocomposites. This work is related to the synthesis of nanocomposites of polypropylene with graphite as filler. The sheets of graphite in nanometer dimensions were made by means of the chemical exfoliation and thermal treatment. The synthesis of the nanocomposites was carried through by means of the in situ polymerization using a metallocene catalyst and with different amounts of inorganic load (0,5; 1 and 2%). The synthesized nanocomposites were characterized by scanning electron microscopy (SEM) and X-Ray diffraction (XRD). (author)

  3. Facile synthesis of MoS{sub 2}/Bi{sub 2}WO{sub 6} nanocomposites for enhanced CO{sub 2} photoreduction activity under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Weili, E-mail: wldai81@126.com [Key Laboratory of Jiangxi Province for Persistant Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, Jiangxi (China); Yu, Juanjuan [Key Laboratory of Jiangxi Province for Persistant Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, Jiangxi (China); Deng, Yiqiang, E-mail: dyq3211@126.com [College of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming 525000 Guangdong (China); Hu, Xu; Wang, Tengyao; Luo, Xubiao [Key Laboratory of Jiangxi Province for Persistant Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, Jiangxi (China)

    2017-05-01

    Highlights: • MoS{sub 2}/Bi{sub 2}WO{sub 6} nanocomposites (MB) were fabricated by a facile two-step approach. • MoS{sub 2} was first used as a cocatalyst coupling with Bi{sub 2}WO{sub 6} for CO{sub 2} photoreduction. • MoS{sub 2} significantly enhanced the photoelectric properties and photoactivity. • The CO{sub 3}{sup 2−}, HCO{sub 3}{sup −} and H{sub 2}CO{sub 3} in CO{sub 2} solution actually act as the reactive substrates. - Abstract: A novel composite material, MoS{sub 2}/Bi{sub 2}WO{sub 6}, has been fabricated via a facile two-step approach. The few layered MoS{sub 2} as a cocatalyst has intimate interactions with the hierarchical flower-like Bi{sub 2}WO{sub 6} microspheres, which boosts the visible light harvesting and charge transferring, and promotes the separation of electron-hole pairs, thus leading to the superior photocatalytic activity. It was found that the as-synthesized MoS{sub 2}/Bi{sub 2}WO{sub 6} nanocomposites exhibited significantly enhanced performance for the photoreduction of CO{sub 2} into hydrocarbons, i.e. methanol and ethanol, as compared with pure Bi{sub 2}WO{sub 6}. The yields of methanol and ethanol obtained over the composite with optimal content of MoS{sub 2} (0.4 wt%) were 36.7 and 36.6 μmol gcat{sup −1} after 4 h of visible light irradiation, respectively, which were 1.94 times higher than that over pure Bi{sub 2}WO{sub 6}. Furthermore, the mechanism of CO{sub 2} photoreduction was also investigated. It indicates that the CO{sub 3}{sup 2−}, HCO{sub 3}{sup −} and H{sub 2}CO{sub 3} generated in CO{sub 2} aqueous solution would be the reactive substrates during the photoreduction reaction, proving the thermodynamic feasibility of CO{sub 2} photoreduction. This work demonstrated that MoS{sub 2} is a very promising candidate for development of highly active photocatalysts, and supplied a facile and simple strategy for designing environmentally benign, cheap non-noble metal, and highly efficient semiconductor

  4. Synthesis and characterization of luminescence magnetic nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Kiplagat, Ayabei [DST/Mintek Nanotechnology Innovation Centre, Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville (South Africa); Onani, Martin O., E-mail: monani@uwc.ac.za [DST/Mintek Nanotechnology Innovation Centre, Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville (South Africa); Meyer, Mervin [DST/Mintek Nanotechnology Innovation Centre, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville (South Africa); Akenga, Teresa A. [Department of Chemistry, University of Eldoret, P.O. Box 1125, Eldoret (Kenya); Dejene, Francis B. [Department of Physics, University of the Free State, QwaQwa Campus, Private Bag X13, Phuthadithaba 9866 (South Africa)

    2016-01-01

    We report a new type of indium based quantum dots which were conjugated to the magnetic Fe{sub 2}O{sub 3} nanoparticles. They were characterized by photoluminescence (PL), high resolution transmission electron microscopy (HRTEM), superconducting quantum interference device (SQUID) and fourier transform infra-red (FTIR). The photoluminescence characteristics of the coupled and uncoupled indium based quantum dots were investigated to determine whether the fluorescing property could be retained in the bifunctional system. Generally, the PL intensity of the quantum dots was observed to reduce significantly and with huge red shift most probably due to quenching effects for the MNPs. The average size of the coupled nanoparticles were found to range between 4 and 5 nm for the quantum dots and range of 6–13 nm for the Fe{sub 2}O{sub 3} magnetic nanoparticles as revealed by both HRTEM and XRD. The highest magnetic saturation reached for both bare and functionalized magnetic nanoparticles was 68.58 emu/g. The FTIR data revealed that the postulated functional groups were actually present in both the bare and functionalized nanoparticles. For instance, Fe–O was observed at around 580 cm{sup −1}, O–H at 3432 cm{sup −1} and thiol group at 2929 cm{sup −1} for meso-2,3-dimercaptosuccinic acid capped Fe{sub 2}O{sub 3} magnetic nanoparticles. The energy dispersive spectroscopy (EDS) also confirmed that all the elements of the nanocomposite were actually present in the designed material.

  5. Efficient One-Pot Synthesis of Colloidal Zirconium Oxide Nanoparticles for High-Refractive-Index Nanocomposites.

    Science.gov (United States)

    Liu, Chao; Hajagos, Tibor Jacob; Chen, Dustin; Chen, Yi; Kishpaugh, David; Pei, Qibing

    2016-02-01

    Zirconium oxide nanoparticles are promising candidates for optical engineering, photocatalysis, and high-κ dielectrics. However, reported synthetic methods for the colloidal zirconium oxide nanoparticles use unstable alkoxide precursors and have various other drawbacks, limiting their wide application. Here, we report a facile one-pot method for the synthesis of colloidally stable zirconium oxide nanoparticles. Using a simple solution of zirconium trifluoroacetate in oleylamine, highly stable zirconium oxide nanoparticles have been synthesized with high yield, following a proposed amidization-assisted sol-gel mechanism. The nanoparticles can be readily dispersed in nonpolar solvents, forming a long-term stable transparent solution, which can be further used to fabricate high-refractive-index nanocomposites in both monolith and thin-film forms. In addition, the same method has also been extended to the synthesis of titanium oxide nanoparticles, demonstrating its general applicability to all group IVB metal oxide nanoparticles.

  6. Study on Synthesis and Antibacterial Properties of Ag NPs/GO Nanocomposites

    Directory of Open Access Journals (Sweden)

    Lei Huang

    2016-01-01

    Full Text Available Using graphene oxide as substrate and stabilizer for the silver nanoparticles, silver nanoparticles-graphene oxide (Ag NPs/GO composites with different Ag loading were synthesized through a facile solution-phase method. During the synthesis process, AgNO3 on GO matrix was directly reduced by NaBH4. The structure characterization was studied through X-ray diffraction (XRD, atomic force microscopy (AFM, high-resolution transmission electron microscope (HRTEM, ultraviolet-visible spectroscopy (UV-Vis, and selected area electron diffraction (SAED. The results show that Ag nanoparticles (Ag NPs with the sizes ranging from 5 to 20 nm are highly dispersed on the surfaces of GO sheets. The shape and size of the Ag NPs are decided by the volume of initial AgNO3 solution added in the GO. The antibacterial activities of Ag NPs/GO nanocomposites were investigated and the result shows that all the produced composites exhibit good antibacterial activities against Gram-negative (G− bacterial strain Escherichia coli (E. coli and Gram-positive (G+ strain Staphylococcus aureus (S. aureus. Moreover, the antibacterial activities of Ag NPs/GO nanocomposites gradually increased with the increasing of volume of initial AgNO3 solution added in the GO and this improvement of the antibacterial activities results from the combined action of size effect and concentration effect of Ag NPs in Ag NPs/GO nanocomposites.

  7. Synthesis of Polyaniline-Coated Graphene Oxide@SrTiO3 Nanocube Nanocomposites for Enhanced Removal of Carcinogenic Dyes from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Syed Shahabuddin

    2016-09-01

    Full Text Available The present investigation highlights the synthesis of polyaniline (PANI-coated graphene oxide doped with SrTiO3 nanocube nanocomposites through facile in situ oxidative polymerization method for the efficient removal of carcinogenic dyes, namely, the cationic dye methylene blue (MB and the anionic dye methyl orange (MO. The presence of oxygenated functional groups comprised of hydroxyl and epoxy groups in graphene oxide (GO and nitrogen-containing functionalities such as imine groups and amine groups in polyaniline work synergistically to impart cationic and anionic nature to the synthesised nanocomposite, whereas SrTiO3 nanocubes act as spacers aiding in segregation of GO sheets, thereby increasing the effective surface area of nanocomposite. The synthesised nanocomposites were characterised by field emission scanning electron microscopy (FESEM, transmission electron microscopy (TEM, thermogravimetric analysis (TGA, X-ray diffraction (XRD, and Fourier transform infrared spectroscopy (FTIR. The adsorption efficiencies of graphene oxide (GO, PANI homopolymer, and SrTiO3 nanocubes-doped nanocomposites were assessed by monitoring the adsorption of methylene blue and methyl orange dyes from aqueous solution. The adsorption efficiency of nanocomposites doped with SrTiO3 nanocubes were found to be of higher magnitude as compared with undoped nanocomposite. Moreover, the nanocomposite with 2 wt % SrTiO3 with respect to graphene oxide demonstrated excellent adsorption behaviour with 99% and 91% removal of MB and MO, respectively, in a very short duration of time.

  8. Radiation induced synthesis of conducting polymer nanocomposite

    International Nuclear Information System (INIS)

    Sayed, T.A.M.

    2013-01-01

    In this work, we prepared a series of Ag/PVA and Ag/PANI nano composites were prepared successfully using a modern and new method. Our synthetic route did not need complicated apparatus, expensive surfactants or additional reducing agents. The prepared nano composite developed optically functional material that does not exist for metal or polymer alone. The present work contains five chapters in addition to the list of figures, tables, abbreviations and references. The first two chapters are concerned with the introduction and reviews of previous studies. Chapter 3 describes the preparation methodology, experimental setup and techniques used in the Ag/PVA and Ag/PANI nano composites processing and analysis. Ag nanoparticles with different particle sizes were prepared via chemical method and gamma- irradiation method. Several techniques were used to detect the structural changes of the nano composites as UV-Visible spectrophotometer, Transmission Electron microscope (TEM), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectrometer, and thermogravimetric analysis (TGA). Chapter 4 includes the obtained results and their discussions: Part I: Synthesis of Ag/PVA nano composite via gamma irradiation From UV/VIS spectroscopy the surface plasmon bands appearing in the visible region (406-422 nm) for Ag/PVA nano composite films are characteristic of the noble metal nanoparticles. The obtained data regarding the change of the absorption intensity and wavelength at maximum absorption and the size of Ag nanoparticles as a function of either irradiation dose or Ag + concentration pointed the following remark: The particle size of Ag nanoparticles in the as-prepared Ag/PVA nano composite films decreases with increasing either irradiation dose or Ag + ion concentration. Transmission electron microscope images illustrated that the average diameter of the Ag nanoparticles is indicated as the peak position of the Gaussian curves of the histogram to be from 40-16 nm. The

  9. Facile fabrication of hollow mesosphere of crystalline SnO2 nanoparticles and synthesis of SnO2@SWCNTs@Reduced Graphene Oxide nanocomposite as efficient Pt-Free counter electrode for dye-sensitized solar cells

    Science.gov (United States)

    Khan, Muhammad Wasim; Yao, Jixin; Zhang, Kang; Zuo, Xueqin; Yang, Qun; Tang, Huaibao; Ur Rehman, Khalid Mehmood; Li, Guang; Wu, Mingzai; Zhu, Kerong; Zhang, Haijun

    2018-06-01

    In this research, SnO2@SWCNTs@Reduced Graphene Oxide based nanocomposite was synthesized by a one step hydrothermal method and reported new cost effective platinum-free counter-electrodes (CEs) in dye-sensitized solar cells (DSSCs). The CEs were formed by using the nanocomposites with the help of a pipette using a doctor-blade technique. The efficiency of this nanocomposite revealed significant elctrocatalytic properties upon falling the triiodide, possessing to synergistic effect of SnO2 nano particles and improved conductivity when SWCNTs dispersed on graphene sheet. Therefore, the power conversion efficiency (PCE) of prepared SnO2@SWCNTs@RGO nanocomposite CE attained of (6.1%) in DSSCs which is equivalent to the value (6.2%) which attained to the value (6.2%) with pure Pt CE as a reference. SnO2@SWCNTs@RGO nanocomposite CEs give more stable catalytic activities for triiodide reduction than SnO2 and SWCNTs CEs in the cyclic voltammetry (CV) analysis. Furthermore, to the subsistence of graphene oxide, the nanocomposite acquired both higher stability and efficiency in the nanocomposite.

  10. Synthesis of new dental nanocomposite with glass nanoparticles

    Directory of Open Access Journals (Sweden)

    Alireza Khavandi

    2013-09-01

    Full Text Available Objective(s: The aim of this study was to synthesis new dental nanocomposites reinforced with fabricated glass nanoparticles and compare two methods for fabrication and investigate the effect of this filler on mechanical properties. Materials and Methods : The glass nanoparticles were produced by wet milling process. The particle size and shape was achieved using PSA and SEM. Glass nanoparticles surface was modified with MPTMS silane. The composite was prepared by mixing these silane-treated nanoparticles with monomers. The resin composition was UDMA /TEGDMA (70/30 weight ratio. Three composites were developed with 5, 7.5 and 10 wt% glass fillers in each group. Two preparation methods were used, in dispersion in solvent method (group D glass nanoparticles were sonically dispersed in acetone and the solution was added to resin, then acetone was evaporated. In non-dispersion in solvent method (group N the glass nanoparticles were directly added to resin. Mechanical properties were investigated included flexural strength, flexural modulus and Vickers hardness. Results: Higher volume of glass nanoparticles improves mechanical properties of composite. Group D has batter mechanical properties than group N. Flexural strength of composite with 10%w filler of group D was 75Mpa against 59 Mpa of the composite with the same filler content of group N. The flexural modulus and hardness of group D is more than group N. Conclusion: It can be concluded that dispersion in solvent method is the best way to fabricate nanocomposites and glass nanoparticles is a significant filler to improve mechanical properties of dental nanocomposite.

  11. Synthesis and characterization of CdS/PVA nanocomposite films

    Science.gov (United States)

    Wang, Hongmei; Fang, Pengfei; Chen, Zhe; Wang, Shaojie

    2007-08-01

    A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd 2+-dispersed poly vinyl-alcohol (PVA) with H 2S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of Cd sbnd S bond at 405 cm -1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect.

  12. Synthesis and characterization of CdS/PVA nanocomposite films

    International Nuclear Information System (INIS)

    Wang Hongmei; Fang Pengfei; Chen Zhe; Wang Shaojie

    2007-01-01

    A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd 2+ -dispersed poly vinyl-alcohol (PVA) with H 2 S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of Cd-S bond at 405 cm -1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect

  13. Synthesis, characterization and electrospinning of corn cob cellulose-graft-polyacrylonitrile and their clay nanocomposites.

    Science.gov (United States)

    Kalaoğlu, Özlem I; Ünlü, Cüneyt H; Galioğlu Atıcı, Oya

    2016-08-20

    This study aims at evaluation of cellulose recovered from agricultural waste (corn cob) in terms of synthesis of graft copolymers, polymer/clay nanocomposites, and nanofibers. The copolymers and nanocomposites were synthesized in aqueous solution using Ce(4+) initiator. Conditions (concentrations of the components, reaction temperature, and period) were determined first for copolymer synthesis to obtain the highest conversion ratio. Then found parameters were used to synthesize nanocomposites adding clay mineral to reaction medium. Although there was a decrease in conversion in nanocomposites syntheses, thermal and rheologic measurements indicated enhancements compared to pristine copolymer. Obtained polymeric materials have been successfully electrospun into nanofibers and characterized. Average diameter of the nanofibers was about 650nm and was strongly influenced by NaMMT amount in the nanocomposite sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Synthesis and properties of unagglomerated nanocomposite particles for nanomedical applications

    Science.gov (United States)

    Rouse, Sarah M.

    2005-11-01

    Methods have been developed to prepare stable, unagglomerated active-medical-agent nanoparticles in a range of sizes, based on reverse-micelle microemulsion techniques. The process used to prepare monodisperse, spherical nanocomposite particles is based on methods originally outlined in detail by Adair et al. and Li et al. The "Molecular Dot" (MD) nanoparticles incorporate a variety of medically-active substances, such as organic fluorophores and therapeutic drugs, internally distributed in silica, titania, calcium phosphate, or calcium phospho-silicate matrices. The synthesis techniques have also been modified to produce nanoparticles containing combinations of fluorophores and medicinal agents, in order to monitor drug release and location. The specific biomedical application for the nanocomposite particles dictates the selection of core and shell-matrix materials. For example, the protective shell-matrices of the silica and titania MDs shield the active-medical agents from damage due to changes in pH, temperature, and other environmental effects. Conversely, the calcium phosphate and calcium phospho-silicate shell-matrix nanoparticles can potentially be engineered to dissolve in physiological environments. The method used to remove residual precursor materials while maintaining a well-dispersed assembly of nanoparticles is critical to the use of nanocolloids in medical applications. The dispersion approach is based on protection-dispersion theory tailored to accommodate the high surface areas and reactivity of sub-50 nm particles in aqueous or water/ethanol mixtures. Dispersion of the nanocomposite particles is further enhanced with the use of size-exclusion high performance liquid chromatography (HPLC) to simultaneously wash and disperse the nanocomposite particle suspensions. The state of dispersion of the nanosuspensions is evaluated using the average agglomeration number (AAN) approach in conjunction with other characterization techniques. The formulation of

  15. ZnS-Graphene nanocomposite: Synthesis, characterization and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Pan Shugang [Key Laboratory for Soft Chemistry and Functional Materials, Nanjing University of Science and Technology, Ministry of Education, Nanjing 210094 (China); Liu Xiaoheng, E-mail: xhliu@mail.njust.edu.cn [Key Laboratory for Soft Chemistry and Functional Materials, Nanjing University of Science and Technology, Ministry of Education, Nanjing 210094 (China)

    2012-07-15

    A ZnS-Graphene nanocomposite was prepared by a facile one-step hydrothermal method using zinc nitrate hexahydrate, ethylenediamine and carbon disulfide as precursors, graphene oxide as a template. The composite was characterized by X-ray power diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, Fourier transform infrared, Raman spectra and fluorescence spectroscopy. The results show that graphene oxide was reduced to graphene in the hydrothermal reaction process. Simultaneously, the graphene sheets in the composite are exfoliated and decorated with ZnS nanoparticles. Furthermore, Raman and fluorescence properties of the composite were observed. ZnS-Graphene nanocomposite displays surface-enhanced Raman scattering activity for graphene oxide, and fluorescence enhancement property compared with pure ZnS sample. - Graphical abstract: Approach of reaction makes the reduction of grapheme oxide and the deposition of Zns on the grapheme sheets occur simultaneously and overcomes the aggregation of the grapheme sheets and Zns. Highlights: Black-Right-Pointing-Pointer Graphene oxide is reduced to graphene in the hydrothermal reaction process. Black-Right-Pointing-Pointer ZnS nanoparticles are attached onto the almost transparent graphene sheets. Black-Right-Pointing-Pointer ZnS-Graphene system shows surface-enhanced Raman scattering (SERS) activity. Black-Right-Pointing-Pointer ZnS-Graphene system displays relatively better fluorescence property than pure ZnS.

  16. Synthesis of polyanthranilic acid–Au nanocomposites by emulsion ...

    Indian Academy of Sciences (India)

    Administrator

    PANA–Au nanocomposites are characterized by SEM, equipped with EDS, TGA, FT–IR, XRD and electrochemical techniques. XRD of ... Polyanthranilic acid; nanocomposite; in situ polymerization; emulsion polymerization; nano- particles. 1.

  17. Synthesis and characterization of fly ash-zinc oxide nanocomposite

    Directory of Open Access Journals (Sweden)

    Kunal Yeole

    2014-04-01

    Full Text Available Fly ash, generated in thermal power plants, is recognized as an environmental pollutant. Thus, measures are required to be undertaken to dispose it in an environmentally friendly method. In this paper an attempt is made to coat zinc oxide nano-particles on the surface of fly ash by a simple and environmentally friendly facile chemical method, at room temperature. Zinc oxide may serve as effective corrosion inhibitor by providing sacrificial protection. Concentration of fly ash was varied as 5, 10 and 15 (w/w % of zinc oxide. It was found that crystallinity increased, whereas particle size, specific gravity and oil absorption value decreased with increased concentration of fly ash in zinc oxide, which is attributed to the uniform distribution of zinc oxide on the surface of fly ash. These nanocomposites can potentially be used in commercial applications as additive for anticorrosion coatings.

  18. Facile fabrication of novel silver-polypyrrole-multiwall carbon nanotubes nanocomposite for replacement of platinum in dye-sensitized solar cell

    Science.gov (United States)

    Rafique, Shaista; Sharif, Rehana; Rashid, Imran; Ghani, Sheeba

    2016-08-01

    This paper demonstrates the facile synthesis of high performance silver-polypyrrole-multiwall carbon nanotubes (Ag-PPy-FMWCNTS) nanocomposites via electrodeposition method on stainless steel substrate and its application as a low cost counter electrode (CE) for the precious platinum (Pt) free DSSC. The nanocomposites were characterized by variety of techniques such as Fourier transforms infrared (FTIR), X-ray diffraction, Scanning electron microscope (SEM), cyclic voltammetry (CV) and Four probe technique respectively. The cyclic voltammetry and Tafel polymerization measurements of Ag-PPy-FMWCNTS nanocomposites CE reveal the favorable electrocatalytic activity and low charge transfer resistance Rct(2.50 Ω cm2) for I3-/I- redox solution. The four probe studies showed the large electrical conductivity (226S cm-1) of Ag-PPy-FMWCNTS nanocomposite. The DSSC assembled with Ag-PPy-FMWCNTS nanocomposites CE display the considerable short circuit current density (13.95 mA cm-2) and acceptable solar to electrical conversion efficiency of 7.6%, which is higher to the efficiency of DSSC with thermally decomposed Pt reference electrode 7.1%. The excellent conversion efficiency, rapid charge transfer in combination with low cost and simple fabrication method of Ag-PPy-FMWCNTS nanocomposites can be exploited as an efficient and potential candidate to replace the Pt CE for large scale production of DSSC.

  19. Facile fabrication of novel silver-polypyrrole-multiwall carbon nanotubes nanocomposite for replacement of platinum in dye-sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Rafique, Shaista; Sharif, Rehana; Ghani, Sheeba [Department of Physics, University of Engineering and Technology, Lahore, 54000 (Pakistan); Rashid, Imran, E-mail: f.imran.rashid@gmail.com [Department of Electrical Engineering, The University of Lahore, Islamabad, 44000 (Pakistan)

    2016-08-15

    This paper demonstrates the facile synthesis of high performance silver-polypyrrole-multiwall carbon nanotubes (Ag-PPy-FMWCNTS) nanocomposites via electrodeposition method on stainless steel substrate and its application as a low cost counter electrode (CE) for the precious platinum (Pt) free DSSC. The nanocomposites were characterized by variety of techniques such as Fourier transforms infrared (FTIR), X-ray diffraction, Scanning electron microscope (SEM), cyclic voltammetry (CV) and Four probe technique respectively. The cyclic voltammetry and Tafel polymerization measurements of Ag-PPy-FMWCNTS nanocomposites CE reveal the favorable electrocatalytic activity and low charge transfer resistance R{sub ct}(2.50 Ω cm{sup 2}) for I{sub 3}{sup −}/I{sup −} redox solution. The four probe studies showed the large electrical conductivity (226S cm{sup −1}) of Ag-PPy-FMWCNTS nanocomposite. The DSSC assembled with Ag-PPy-FMWCNTS nanocomposites CE display the considerable short circuit current density (13.95 mA cm{sup −2}) and acceptable solar to electrical conversion efficiency of 7.6%, which is higher to the efficiency of DSSC with thermally decomposed Pt reference electrode 7.1%. The excellent conversion efficiency, rapid charge transfer in combination with low cost and simple fabrication method of Ag-PPy-FMWCNTS nanocomposites can be exploited as an efficient and potential candidate to replace the Pt CE for large scale production of DSSC.

  20. Facile fabrication of novel silver-polypyrrole-multiwall carbon nanotubes nanocomposite for replacement of platinum in dye-sensitized solar cell

    International Nuclear Information System (INIS)

    Rafique, Shaista; Sharif, Rehana; Ghani, Sheeba; Rashid, Imran

    2016-01-01

    This paper demonstrates the facile synthesis of high performance silver-polypyrrole-multiwall carbon nanotubes (Ag-PPy-FMWCNTS) nanocomposites via electrodeposition method on stainless steel substrate and its application as a low cost counter electrode (CE) for the precious platinum (Pt) free DSSC. The nanocomposites were characterized by variety of techniques such as Fourier transforms infrared (FTIR), X-ray diffraction, Scanning electron microscope (SEM), cyclic voltammetry (CV) and Four probe technique respectively. The cyclic voltammetry and Tafel polymerization measurements of Ag-PPy-FMWCNTS nanocomposites CE reveal the favorable electrocatalytic activity and low charge transfer resistance R_c_t(2.50 Ω cm"2) for I_3"−/I"− redox solution. The four probe studies showed the large electrical conductivity (226S cm"−"1) of Ag-PPy-FMWCNTS nanocomposite. The DSSC assembled with Ag-PPy-FMWCNTS nanocomposites CE display the considerable short circuit current density (13.95 mA cm"−"2) and acceptable solar to electrical conversion efficiency of 7.6%, which is higher to the efficiency of DSSC with thermally decomposed Pt reference electrode 7.1%. The excellent conversion efficiency, rapid charge transfer in combination with low cost and simple fabrication method of Ag-PPy-FMWCNTS nanocomposites can be exploited as an efficient and potential candidate to replace the Pt CE for large scale production of DSSC.

  1. Porous Fe-Mn-O nanocomposites: Synthesis and supercapacitor electrode application

    Directory of Open Access Journals (Sweden)

    Guoxing Zhu

    2016-06-01

    Full Text Available Transition metal oxide micro-/nanostructures demonstrate high potential applications in energy storage devices. Here, we report a facile synthesis of highly homogeneous oxide composites with porous structure via a coordination polymer precursor, which was prepared with the assistance of tartaric acid. The typical product, Fe-Mn-O composite was demonstrated here. The obtained Fe-Mn-O product was systemically characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, elemental mapping analysis, and X-ray photoelectron spectroscopy. It was demonstrated that the Fe-Mn-O nanocomposite shows interconnected porous structure, in which iron, manganese, and oxygen are uniformly distributed. In addition, the Fe-Mn-O nanocomposite was then fabricated as capacitor electrodes. Operating in an aqueous neutral solution, the Fe-Mn-O composite electrodes showed an wide working potential window from −0.2 to 1.0 V (vs. SCE, and a specific capacitance of 86.7 Fg−1 or 0.4 Fcm−2 at a constant current density of 1 Ag−1 with good cycle life. This study offers a new precursor approach to prepare porous metal oxide composites, which would be applied in energy-storage/conversion devices, catalysts, sensors, and so on.

  2. Synthesis of Conductive Polymeric Nanocomposites for Applications in Responsive Materials

    Science.gov (United States)

    Chavez, Jessica

    concentration as well as the extension of the reaction time. The overall interaction between the conductive polymer and the commercial fibers showed that the conductive polymer was physically adsorbed to the commercial fiber. This physical adsorption caused a decrease in conductive efficiency as a function of repeated washes because the weak intermolecular forces between the conductive polymer and the commercial fiber. This led to the synthesis of conductive films and nanofibers by integrating the conductive polymers directly into a cellulose acetate matrix. The voltage efficiency of the conductive films was lower compared to the coated commercial fiber nanocomposites. However, the conductive material generated greater lux values compared to the coated commercial fiber nanocomposites. Theses conductive materials can be applied to applications in both the medical field and water filtration. The conductive films can be used to create a sensor based system that can trigger a sensor to signify when bandages used for wound management need to be changed. The conductive nanofibers can be used in water filtration as a means of electroplating metals ions from contaminated water. Overall, the synthesis of these conductive materials can be applicable for responsive materials.

  3. Synthesis and characterization of barium ferrite–silica nanocomposites

    International Nuclear Information System (INIS)

    Aguilar-González, M.A.; Mendoza-Suárez, G.; Padmasree, K.P.

    2013-01-01

    In this work, we prepared barium ferrite-silica (BaM-SiO 2 ) nanocomposites of different molar ratios by high-energy ball milling, followed by heat-treatment at different temperatures. The microstructure, morphology and magnetic properties were characterized for different synthesis conditions by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The results indicate that 15 h of milling was enough to avoid the generation of hematite phase and to get a good dispersion of barium ferrite particles in the ceramic matrix. For milling periods beyond 15 h and heat treatment above 900 °C, the XRD patterns showed the presence of hematite phase caused by the decomposition of BaM. The agglomerate size observed through SEM analysis was around 150 nm with a good BaM dispersion into the SiO 2 matrix. The highest saturation magnetization (Ms) value obtained was 43 emu/g and the corresponding coercivity (Hc) value of 3.4 kOe for the composition 60BaM-40SiO 2 milled for 15 h and heat treated at 900 °C. This coercivity value is acceptable for the application in magnetic recording media. Highlights: • Barium ferrite–silica nanocomposites were prepared by high energy ball milling. • Optimal processing time is 15 h milling and heat treatment at 900 °C. • This is enough to avoid the generation of hematite phase. • Obtain good dispersion of barium ferrite particles in the ceramic matrix • Above this processing time shows the presence of increased amount of hematite

  4. Synthesis and characterization of intercalated polyaniline-clay nanocomposite using supercritical CO2

    Science.gov (United States)

    Abdelraheem, A.; El-Shazly, A. H.; Elkady, M. F.

    2018-05-01

    Lately, supercritical CO2 (SCCO2) have been getting great interest. It can be used in numerous applications because it is environmentally friendly, safe, comparatively low cost, and nonflammable. One of its applications is being a solvent in the synthesis of polymeric-clay nanocomposite. In this paper, intercalated polyaniline-clay nanocomposite (PANC) was prepared using SCCO2. The intercalation structure of polyaniline chains between clay layers was verified by various characterization techniques. Scanning electron microscope and transmission electron microscope (SEM-TEM) were used to show the morphology of the synthesized nanocomposite. The molecular structure of PANC nanocomposite was confirmed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The BET surface area and the conductivity of the nanocomposite were determined.

  5. Novel Electrochemical Synthesis of Polypyrrole/Ag Nanocomposite and Its Electrocatalytic Performance towards Hydrogen Peroxide Reduction

    OpenAIRE

    Ruma Gupta; Kavitha Jayachandran; J. S. Gamare; B. Rajeshwari; Santosh K. Gupta; J. V. Kamat

    2015-01-01

    A simple electrochemical method of synthesis of polypyrrole/silver (PPy/Ag) nanocomposite is presented. The method is based on potentiodynamic polymerization of pyrrole followed by electrodeposition of silver employing a single potentiostatic pulse. The synthesized PPy film has embedded Ag nanocubes. The morphology and structure of the resulting nanocomposite were characterized by field emission scanning electron microscopy and X-ray diffraction. Electron paramagnetic resonance studies showed...

  6. Synthesis of alumina-metal nanocomposites by mechanical alloying

    International Nuclear Information System (INIS)

    Osso, D.; Caer, G. le; Begin-Colin, S.; Mocellin, A.; Matteazzi, P.

    1993-01-01

    The synthesis of nanometer-sized α-Al 2 O 3 -metal composites can be performed by room temperature ball-milling of mixtures of metal-oxides and aluminium as shown by Matteazzi and Le Caer. The average crystallite size of the alumina-metal composite so obtained is in general about 10nm. Such composites may also be prepared by direct grinding of a mixture of α-Al 2 O 3 and of a metal or an alloy. The present work is devoted to the study of the reaction mechanisms by X-Ray diffraction and 57 Fe Moessbauer spectroscopy for the α-Al 2 O 3 -Cr, α-Al 2 O 3 -Fe, α-Al 2 O 3 -(Fe-Cr) and α-Al 2 O 3 -Ti systems. Moessbauer spectroscopy shows that non-completely reduced Fe, partly in the form of Fe 2+ , still exists at the end of the synthesis and belongs to a ternary Al-Fe-O oxide in α-Al 2 O 3 -Fe composites although it cannot be indexed by X-Ray diffraction. The Fe 2+ component is mainly associated with iron environments in or similar to those of hercynite. Species like Fe 3+ in Al 2 O 3 or in grain boundaries are observed, Fe 4+ and Fe 0 cannot be excluded. Differences are obtained by reactive milling and by direct milling the reaction products. Reactive milling of Al-TiO 2 (anatase) yields α-Al 2 O 3 -Ti nanocomposites. The transient formation of a high-pressure orthorhombic form of TiO 2 of the α-PbO 2 type is observed. (orig.)

  7. One-step synthesis and structural features of CdS/montmorillonite nanocomposites.

    Science.gov (United States)

    Han, Zhaohui; Zhu, Huaiyong; Bulcock, Shaun R; Ringer, Simon P

    2005-02-24

    A novel synthesis method was introduced for the nanocomposites of cadmium sulfide and montmorillonite. This method features the combination of an ion exchange process and an in situ hydrothermal decomposition process of a complex precursor, which is simple in contrast to the conventional synthesis methods that comprise two separate steps for similar nanocomposite materials. Cadmium sulfide species in the composites exist in the forms of pillars and nanoparticles, the crystallized sulfide particles are in the hexagonal phase, and the sizes change when the amount of the complex for the synthesis is varied. Structural features of the nanocomposites are similar to those of the clay host but changed because of the introduction of the sulfide into the clay.

  8. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiaoning [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Tian, Mingwei [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Qu, Lijun, E-mail: lijunqu@126.com [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Zhu, Shifeng [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Guo, Xiaoqing [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Han, Guangting [Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); and others

    2014-10-30

    Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  9. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    International Nuclear Information System (INIS)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting

    2014-01-01

    Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric

  10. Synthesis, characterization and biocompatibility evaluation of hydroxyapatite - gelatin polyLactic acid ternary nanocomposite

    Directory of Open Access Journals (Sweden)

    Z. Nabipour

    2016-04-01

    Full Text Available Objective(s: The current study reports the production and biocompatibility evaluation of a ternary nanocomposite consisting of HA, PLA, and gelatin for biomedical application.Materials and Methods: Hydroxyapatite nanopowder (HA: Ca10(PO46(OH2 was produced by burning the bovine cortical bone within the temperature range of 350-450 oC followed by heating in an oven at 800. Synthesis of the ternary nanocomposite was carried out in two steps: synthesis of gelatin-hydroxyapatite binary nanocomposite and addition of poly lactic acid with different percentages to the resulting composition. The crystal structure was determined by X-ray diffraction (XRD, while major elements and impurities of hydroxyapatite were identified by elemental analysis of X-ray fluorescence (XRF. Functional groups were determined by Fourier transform infrared spectroscopy (FTIR. Morphology and size of the nanocomposites were evaluated using field emission scanning electron microscope (FE-SEM.Biocompatibility of nanocomposites was investigated by MTT assay. Results: XRD patterns verified the ideal crystal structure of the hydroxyapatite, which indicated an appropriate synthesis process and absence of disturbing phases. Results of FTIR analysis determined the polymers’ functional groups, specified formation of the polymers on the hydroxyapatite surface, and verified synthesis of nHA/PLA/Gel composite. FESEM images also indicated the homogeneous structure of the composite in the range of 50 nanometers. MTT assay results confirmed the biocompatibility of nanocomposite samples.Conclusion: This study suggested that the ternary nanocomposite of nHA/PLA/Gel can be a good candidate for biomedical application such as drug delivery systems, but for evaluation of its potential in hard tissue replacement, mechanical tests should be performed.

  11. Synthesis of poly(furfuryl alcohol)/montmorillonite nanocomposites ...

    Indian Academy of Sciences (India)

    The purpose of this study was to obtain poly(furfuryl alcohol) nanocomposites with Algerian organically modified clay (termed 12-montmorillonite). The formation of poly(furfuryl alcohol) was confirmed by infrared spectroscopy (IR); the prepared nanocomposites were characterized by X-ray diffraction (XRD), transmission ...

  12. Ultrasound assisted synthesis of PMMA/clay nanocomposites: Study ...

    Indian Academy of Sciences (India)

    The Young's modulus, breaking stress, elongation at break, toughness, yield stress and yield strain of the nanocomposites as a function of different clay concentrations and ultrasonic power were measured. Particle diameter of the nanocomposites was measured by laser diffraction technique. Oxygen permeability of the ...

  13. Synthesis and Investigation of Carbon-Based Nanocomposites for Supercapacitors

    OpenAIRE

    LI WAN

    2018-01-01

    Carbon-based nanocomposites were synthesized for high-performance supercapacitors. The coalition between each of the constituent in the nanocomposites and the performance was investigated. Continuous efforts have been put to improve the supercapacitor assembly techniques from conventional supercapacitor to all-solid-state supercapacitor and to binder-free supercapacitor.

  14. Synthesis and characterization of nanocomposites based on poly(3 ...

    Indian Academy of Sciences (India)

    The structure and morphologies of LNMO/P3HT- g -CNTs nanocomposites have also been performed by SEM, XRD and TEM. The electrochemical performance of LNMO/P3HT- g -CNTs nanocomposites as cathode materials of lithium-ion batteries were investigated by cyclic voltammetry and electrochemical impedance ...

  15. Review on the progress in synthesis and application of magnetic carbon nanocomposites

    Science.gov (United States)

    Zhu, Maiyong; Diao, Guowang

    2011-07-01

    This review focuses on the synthesis and application of nanostructured composites containing magnetic nanostructures and carbon-based materials. Great progress in fabrication of magnetic carbon nanocomposites has been made by developing methods including filling process, template-based synthesis, chemical vapor deposition, hydrothermal/solvothermal method, pyrolysis procedure, sol-gel process, detonation induced reaction, self-assembly method, etc. The applications of magnetic carbon nanocomposites expanded to a wide range of fields such as environmental treatment, microwave absorption, magnetic recording media, electrochemical sensor, catalysis, separation/recognization of biomolecules and drug delivery are discussed. Finally, some future trends and perspectives in this research area are outlined.

  16. Facile hydrothermal growth graphene/ZnO nanocomposite for development of enhanced biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Low, Sze Shin [Department of Electrical and Electronic Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor (Malaysia); Division of Materials, Mechanics and Structures, Center of Nanotechnology and Advanced Materials, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor (Malaysia); Tan, Michelle T.T., E-mail: Michelle.Tan@nottingham.edu.my [Department of Electrical and Electronic Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor (Malaysia); Division of Materials, Mechanics and Structures, Center of Nanotechnology and Advanced Materials, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor (Malaysia); Loh, Hwei-San [School of Biosciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor (Malaysia); Biotechnology Research Centre, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor (Malaysia); Khiew, Poi Sim [Division of Materials, Mechanics and Structures, Center of Nanotechnology and Advanced Materials, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor (Malaysia); Chiu, Wee Siong [Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-01-15

    Graphene/zinc oxide nanocomposite was synthesised via a facile, green and efficient approach consisted of novel liquid phase exfoliation and solvothermal growth for sensing application. Highly pristine graphene was synthesised through mild sonication treatment of graphite in a mixture of ethanol and water at an optimum ratio. The X-ray diffractometry (XRD) affirmed the hydrothermal growth of pure zinc oxide nanoparticles from zinc nitrate hexahydrate precursor. The as-prepared graphene/zinc oxide (G/ZnO) nanocomposite was characterised comprehensively to evaluate its morphology, crystallinity, composition and purity. All results clearly indicate that zinc oxide particles were homogenously distributed on graphene sheets, without any severe aggregation. The electrochemical performance of graphene/zinc oxide nanocomposite-modified screen-printed carbon electrode (SPCE) was evaluated using cyclic voltammetry (CV) and amperometry analysis. The resulting electrode exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H{sub 2}O{sub 2}) in a linear range of 1–15 mM with a correlation coefficient of 0.9977. The sensitivity of the graphene/zinc oxide nanocomposite-modified hydrogen peroxide sensor was 3.2580 μAmM{sup −1} with a limit of detection of 7.4357 μM. An electrochemical DNA sensor platform was then fabricated for the detection of Avian Influenza H5 gene based on graphene/zinc oxide nanocomposite. The results obtained from amperometry study indicate that the graphene/zinc oxide nanocomposite-enhanced electrochemical DNA biosensor is significantly more sensitive (P < 0.05) and efficient than the conventional agarose gel electrophoresis. - Highlights: • One step, green and facile exfoliation of graphite in ethanol/water mixture. • G/ZnO nanocomposite prepared via simple, green low temperature solvothermal method. • CV and amperometric study of G/ZnO nanocomposite towards H{sub 2}O{sub 2} with R{sup 2} of 0.9977.

  17. Single Step In Situ Synthesis and Optical Properties of Polyaniline/ZnO Nanocomposites

    Directory of Open Access Journals (Sweden)

    Deepali Sharma

    2014-01-01

    Full Text Available Polyaniline/ZnO nanocomposites were prepared by in situ oxidative polymerization of aniline monomer in the presence of different weight percentages of ZnO nanostructures. The steric stabilizer added to prevent the agglomeration of nanostructures in the polymer matrix was found to affect the final properties of the nanocomposite. ZnO nanostructures of various morphologies and sizes were prepared in the absence and presence of sodium lauryl sulphate (SLS surfactant under different reaction conditions like in the presence of microwave radiation (microwave oven, under pressure (autoclave, under vacuum (vacuum oven, and at room temperature (ambient condition. The conductivity of these synthesized nanocomposites was evaluated using two-probe method and the effect of concentration of ZnO nanostructures on conductivity was observed. X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR, and UV-visible (UV-VIS spectroscopy techniques were used to characterize nanocomposites. The optical energy band gap of the nanocomposites was calculated from absorption spectra and ranged between 1.5 and 3.21 eV. The reported values depicted the blue shift in nanocomposites as compared to the band gap energies of synthesized ZnO nanostructures. The present work focuses on the one-step synthesis and potential use of PANI/ZnO nanocomposite in molecular electronics as well as in optical devices.

  18. Synthesis and characterization of nanocomposites ZnO / polypyrrole for anti corrosive application

    International Nuclear Information System (INIS)

    Valenca, D.P.; Bouchonneau, N.; Vieira, M.R.S.; Alves, K.G.B.; Melo, C.P. de; Urtiga Filho, S.L.

    2014-01-01

    Nanoparticles of metal oxides and conductive polymers have been investigated as alternative additives in corrosion protection of oxidizable metals. In this hybrid nanocomposites work Polypyrrole-ZnO were synthesized and characterized as a potential application as industrial paint anti corrosive additive. The different steps of the synthesis and characterization of nanocomposites are described. The nanocomposites were obtained from the emulsion polymerization of aqueous solutions of pyrrole and sodium dodecyl sulfate containing ZnO nanoparticles dispersed in the mass. The nanoparticles were characterized by scanning electron microscopy and transmission, dynamic light scattering, diffraction of X-rays and techniques of infrared spectroscopy. From the characterization techniques, it was possible to determine the average size of nanoparticles of ZnO and ZnO-Polypyrrole. The peaks in the diffraction pattern of X-rays observed in the nanocomposite were the same as in ZnO, confirming the presence of ZnO in the composite. (author)

  19. Synthesis, Structural Characterization and Up-Conversion Luminescence Properties of NaYF4:Er3+,Yb3+@MOFs Nanocomposites

    Science.gov (United States)

    Giang, Lam Thi Kieu; Marciniak, Lukasz; Huy, Tran Quang; Vu, Nguyen; Le, Ngo Thi Hong; Binh, Nguyen Thanh; Lam, Tran Dai; Minh, Le Quoc

    2017-10-01

    This paper describes a facile synthesis of NaYF4:Er3+,Yb3+ nanoparticles embraced in metal-organic frameworks (MOFs), known as NaYF4:Er3+, Yb3+@MOFs core/shell nanostructures, by using iron(III) carboxylate (MIL-100) and zeolitic imidazolate frameworks (ZIF-8). Morphological, structural and optical characterization of these nanostructures were investigated by field emission-scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, and up-conversion luminescence measurements. Results showed that spherical-shaped NaYF4:Er3+,Yb3+@MIL-100 nanocomposites with diameters of 150-250 nm, and rod-shaped NaYF4:Er3+,Yb3+@ZIF-8 nanocomposites with lengths of 300-550 nm, were successfully synthesized. Under a 980-nm laser excitation at room temperature, the NaYF4:Er3+,Yb3+@MOFs nanocomposites exhibited strong up-conversion luminescence with two emission bands in the green part of spectrum at 520 nm and 540 nm corresponding to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+ ions, respectively, and a red emission band at 655 nm corresponding to the 4F9/2 → 4I15/2 transition of Er3+ ions. The above properties of NaYF4:Er3+,Yb3+@MOFs make them promising candidates for applications in biotechnology.

  20. Synthesis and characterization of PMMA/clay nanocomposites prepared by in situ polymerization assisted by sonication

    International Nuclear Information System (INIS)

    Prado, Bruna R.; Bartoli, Julio R.; Ito, Edson N.

    2015-01-01

    In this work is presented the synthesis of nanocomposites of poly(methyl methacrylate), PMMA, with organically montmorillonite (OMMT) modified clays by in situ polymerization assisted by sonication. A statistically designed experiment was used, central composing design (CCD), to study the effect of synthesis variables on the dispersion of nanoparticles in PMMA matrix. The processing and formulation factors studied were: energy of sonication and Flory-Huggins interaction parameter between PMMA and organoclay. The structural (XRD) and morphological (TEM) characterizations of the PMMA/OMMT nanocomposites are compared with the literature. It was observed significant exfoliation of OMMT modified with hydroxyl groups in the nanocomposites of PMMA, mainly at the low ultrasonic energy level (90 and 105 kJ) studied. (author)

  1. Synthesis of photothermal nanocomposites and their application to antibacterial assays

    Science.gov (United States)

    Yang, Ning; Wang, Chun; Wang, Xiaoyu; Li, Lidong

    2018-04-01

    In this work, we report a novel gold nanorod (AuNR)-based nanocomposite that shows strong binding to bacterium and high antibacterial efficiency. The AuNRs were used as a photothermal material to transform near-infrared radiation (NIR) into heat. We selected poly (acrylic acid) to modify the surface of the AuNRs based on a simple self-assembly method. After conjugation of the bacterium-binding molecule vancomycin, the nanocomposites were capable of efficiently gathering on the cell walls of bacteria. The nanocomposites exhibited a high bacterial inhibition capability owing to NIR-induced heat generation in situ. Therefore, the prepared photothermal nanocomposites show great potential for use in antibacterial assays.

  2. Synthesis of thermoresponsive poly(N-isopropylacrylamide)/clay nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.P.; Lyu, S.G. [Yeungnam Univeristy, Kyongsan (Korea); Bae, K.S. [Andong Institute of Information and Technology, Andong (Korea); Sur, G.S. [Yeungnam Univeristy, Kyungsan (Korea)

    2001-03-01

    MAPTAC-MMT was prepared by exchanging the mineral cation (sodium montmorillonite) with 3-(methacryloyl amino) propyltrimethyl ammonium chloride, thus rendering the mineral organophilic and forming polymerizable moieties directly bonded to the surface of montmorillonite (MMT). Thermoresponsive nanocomposites (PNIPAM-MMT) were synthesized by polymerization of N-isopropyl acrylamide in an aqueous suspension of MAPTAC-MMT at room temperature. Thermoresponsive nanocomposites exhibited a low critical solution temperature (LCST) similar to unmodified poly(N-isopropyl acrylamide) (PNIPAM). The LCST of thermoresponsive nanocomposites decreased in proportion to the amount of MAPTAC-MMT. TGA results showed that the thermal stability of thermoresponsieve nanocomposites was improved compared to PNIPAM itself the thermoresponsive polymer. (author). 25 refs., 9 figs.

  3. Synthesis of silver-titanium dioxide nanocomposites for antimicrobial applications

    Science.gov (United States)

    Yang, X. H.; Fu, H. T.; Wang, X. C.; Yang, J. L.; Jiang, X. C.; Yu, A. B.

    2014-08-01

    Silver-titanium dioxide (Ag-TiO2) nanostructures have attracted increasing attention because of unique functional properties and potential applications in many areas such as photocatalysis, antibacterial, and self-cleaning coatings. In this study, Ag@TiO2 core-shell nanostructures and Ag-decorated TiO2 particles (TiO2@Ag) (the size of these two nanoparticles is ranging from 200-300 nm) have been synthesized by a developed facile but efficient method. These two types of hybrid nanostructures, characterized by various advanced techniques (TEM, XRD, BET and others), exhibit unique functional properties particularly in antibacterial toward Gram negative Escherichia coli, as a case study. Specifically: (i) the TiO2@Ag nanoparticles are superior in bacterial growth inhibition in standard culture conditions (37 °C incubator) to the Ag@TiO2 core-shell ones, in which silver may dominate the antibacterial performance; (ii) while after UV irradiation treatment, the Ag@TiO2 core-shell nanoparticles exhibit better performance in killing grown bacteria than the TiO2@Ag ones, probably because of the Ag cores facilitating charge separation for TiO2, and thus produce more hydroxyl radicals on the surface of the TiO2 particles; and (iii) without UV irradiation, both TiO2@Ag and Ag@TiO2 nanostructures show poor capabilities in killing mature bacteria. These findings would be useful for designing hybrid metal oxide nanocomposites with desirable functionalities in bioapplications in terms of sterilization, deodorization, and water purification.

  4. Multifunctional Nanocomposites for Improved Sustainability and Protection of Facilities

    Science.gov (United States)

    2015-05-01

    ballistic-resistant panels. Equipment needed for cur- ing the epoxy is more expensive, and the viscosity of the epoxy material is too high for use in common...fracture. It was concluded that the lower V50 of the clay -modified Nylon 6 nanocomposite was brittle and had lower toughness than that of the neat...levels (0.5, 1.0, 2.0, and 3.0 wt%) in the polyester matrix. Higher load- ing of the CNTs was attempted but was constrained by the viscosity increase of

  5. Synthesis of Ag2Se–graphene–TiO2 nanocomposite and analysis of ...

    Indian Academy of Sciences (India)

    2017-11-16

    Nov 16, 2017 ... Synthesis of Ag2Se–graphene–TiO2 nanocomposite and analysis of photocatalytic ... photoactivity, obtaining a total CH3OH yield of 3.52μmol g. −1 h. −1 after 48h. .... a = b = 3.78 Å and c = 9.51 Å (JCPDS PDF#00-021-1279).

  6. Chemically stabilized reduced graphene oxide/zirconia nanocomposite: synthesis and characterization

    Science.gov (United States)

    Sagadevan, Suresh; Zaman Chowdhury, Zaira; Enamul Hoque, Md; Podder, Jiban

    2017-11-01

    In this research, chemical method was used to fabricate reduced graphene oxide/zirconia (rGO/ZrO2) nanocomposite. X-ray Diffraction analysis (XRD) was carried out to examine the crystalline structure of the nanocomposites. The nanocomposite prepared here has average crystallite size of 14 nm. The surface morphology was observed using scanning electron microscopic analysis (SEM) coupled with electron dispersion spectroscopy (EDS) to detect the chemical element over the surface of the nanocomposites. High-resolution Transmission electron microscopic analysis (HR-TEM) was carried out to determine the particle size and shape of the nanocomposites. The optical property of the prepared samples was determined using UV-visible absorption spectrum. The functional groups were identified using FTIR and Raman spectroscopic analysis. Efficient, cost effective and properly optimized synthesis process of rGO/ZrO2 nanocomposite can ensure the presence of infiltrating graphene network inside the ZrO2 matrix to enhance the electrical properties of the hybrid composites up to a greater scale. Thus the dielectric constant, dielectric loss and AC conductivity of the prepared sample was measured at various frequencies and temperatures. The analytical results obtained here confirmed the homogeneous dispersion of ZrO2 nanostructures over the surface of reduced graphene oxide nanosheets. Overall, the research demonstrated that the rGO/ZrO2 nano-hybrid structure fabricated here can be considered as a promising candidate for applications in nanoelectronics and optoelectronics.

  7. Poly(2-aminothiazole)-silica nanocomposite particles: Synthesis and morphology control

    Science.gov (United States)

    Zou, Hua; Wu, Di; Sun, Hao; Chen, Suwu; Wang, Xia

    2018-04-01

    Synthesis of conducting polymer-silica colloidal nanocomposites has been recognized as an effective method to overcome the poor processability of heterocyclic conducting polymers prepared by chemical oxidative method. However, the morphology control of such conducting polymer-silica nanocomposites was seldomly reported in the literature. Novel poly(2-aminothiazole)(PAT)-silica nanocomposite particles can be conveniently prepared by chemical oxidative polymerization of 2-aminothiazole using CuCl2 oxidant in the presence of ∼20 nm silica nanoparticles. The effects of varying the oxidant/monomer ratio and silica sol concentration on the morphology and size of the resulting PAT-silica nanocmposites have been studied. Optimization of the oxidant/monomer molar ratio and initial silica sol concentration allows relatively round spherical particles of 150-350 nm in diameter to be achieved. The nanocomposite particles have a well-defined raspberry-like morphology with a silica-rich surface, but a significant fraction of PAT component still exists on the surface and, which is beneficial for its applications. Furthermore, the surface compositions of the colloidal nanocomposites could be regulated to some extent. Based on the above results, a possible formation mechanism of the spherical nanocomposite particles is proposed.

  8. Synthesis of polyetherimide / halloysite nanotubes (PEI/HNTs) based nanocomposite membrane towards hydrogen storage

    Science.gov (United States)

    Muthu, R. Naresh; Rajashabala, S.; Kannan, R.

    2018-04-01

    Even though hydrogen is considered as green and clean energy sources of future, the blooming of hydrogen economy mainly relies on the development of safe and efficient hydrogen storage medium. The present work is aimed at the synthesis and characterization of polyetherimide/acid treated halloysite nanotubes (PEI/A-HNTs) nanocomposite membranes for solid state hydrogen storage medium, where phase inversion technique was adopted for the synthesis of nanocomposite membrane. The synthesized PEI/A-HNTs nanocomposite membranes were characterized by XRD, FTIR, SEM, EDX, CHNS elemental analysis and TGA. Hydrogenation studies were performed using a Sievert's-like hydrogenation setup. The important conclusions arrived from the present work are the PEI/A-HNTs nanocomposite membranes have better performance with a maximum hydrogen storage capacity of 3.6 wt% at 100 °C than pristine PEI. The adsorbed hydrogen possesses the average binding energy of 0.31 eV which lies in the recommended range of US- DOE 2020 targets. Hence it is expected that the PEI/A-HNTs nanocomposite membranes may have bright extent in the scenario of hydrogen fuel cell applications.

  9. One-pot synthesis of Fe{sub 3}O{sub 4}/Fe/MWCNT nanocomposites via electrical wire pulse for Li ion battery electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Duk-Hee; Seo, Seung-Deok; Lee, Gwang-Hee [School of Civil, Environmental and Architectural Engineering, Korea University, 145, Anam-Ro, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of); Hong, Hyun-Seon [Advanced Materials and Processing Center, Institute for Advanced Engineering, Yongin 449-863 (Korea, Republic of); Kim, Dong-Wan, E-mail: dwkim1@korea.ac.kr [School of Civil, Environmental and Architectural Engineering, Korea University, 145, Anam-Ro, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of)

    2014-09-01

    Highlights: • Synthesis of Fe{sub 3}O{sub 4}/Fe/MWCNT nanocolloids using an electrical wire explosion process. • Electrical connection of Fe{sub 3}O{sub 4} to a current collector by the conducting networks. • Improved electrochemical performance of Fe{sub 3}O{sub 4}/Fe/MWCNT nanocomposite electrodes. - Abstract: Nanocomposites containing Fe{sub 3}O{sub 4}/Fe/multiwalled carbon nanotubes (MWCNT) were prepared via an electrical wire pulse process (a top-down approach) using Fe wire and dispersed, functionalized MWCNT in deionized water (DIW) at room temperature. The structural and electrochemical characteristics of the resulting nanocomposites were investigated in detail. When used as an anode for Li ion batteries, the Fe{sub 3}O{sub 4}/Fe/MWCNT nanocomposites exhibited greater cycle stability and rate performance than plain Fe{sub 3}O{sub 4}/Fe composites, with a capacity of 460 mA h g{sup −1} at a rate of 168 mA g{sup −1} after 50 cycles. The enhanced performance was attributed to superior electrical conductivity and buffering effect of the MWCNTs on volume changes of the anodes. This process is a promising facile method for lithium ion battery anode material synthesis.

  10. Facile hydrothermal growth graphene/ZnO nanocomposite for development of enhanced biosensor.

    Science.gov (United States)

    Low, Sze Shin; Tan, Michelle T T; Loh, Hwei-San; Khiew, Poi Sim; Chiu, Wee Siong

    2016-01-15

    Graphene/zinc oxide nanocomposite was synthesised via a facile, green and efficient approach consisted of novel liquid phase exfoliation and solvothermal growth for sensing application. Highly pristine graphene was synthesised through mild sonication treatment of graphite in a mixture of ethanol and water at an optimum ratio. The X-ray diffractometry (XRD) affirmed the hydrothermal growth of pure zinc oxide nanoparticles from zinc nitrate hexahydrate precursor. The as-prepared graphene/zinc oxide (G/ZnO) nanocomposite was characterised comprehensively to evaluate its morphology, crystallinity, composition and purity. All results clearly indicate that zinc oxide particles were homogenously distributed on graphene sheets, without any severe aggregation. The electrochemical performance of graphene/zinc oxide nanocomposite-modified screen-printed carbon electrode (SPCE) was evaluated using cyclic voltammetry (CV) and amperometry analysis. The resulting electrode exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) in a linear range of 1-15 mM with a correlation coefficient of 0.9977. The sensitivity of the graphene/zinc oxide nanocomposite-modified hydrogen peroxide sensor was 3.2580 μAmM(-1) with a limit of detection of 7.4357 μM. An electrochemical DNA sensor platform was then fabricated for the detection of Avian Influenza H5 gene based on graphene/zinc oxide nanocomposite. The results obtained from amperometry study indicate that the graphene/zinc oxide nanocomposite-enhanced electrochemical DNA biosensor is significantly more sensitive (P < 0.05) and efficient than the conventional agarose gel electrophoresis. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Microwave-assisted synthesis of Mn{sub 3}O{sub 4} nanoparticles@reduced graphene oxide nanocomposites for high performance supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    She, Xiao; Zhang, Xinmin; Liu, Jingya [School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Li, Liang, E-mail: msell08@163.com [School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Yu, Xianghua; Huang, Zhiliang [School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Shang, Songmin, E-mail: shang.songmin@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China)

    2015-10-15

    Highlights: • Mn{sub 3}O{sub 4}@rGO nanocomposites were prepared by one-step microwave-assisted method. • The growth of Mn{sub 3}O{sub 4} and the reduction of graphene oxide occurred simultaneously. • Specific capacitance of the nanocomposite is higher than those of rGO and Mn{sub 3}O{sub 4}. • The nanocomposites have good rate capability and cycling stability. - ABSTRACT: One-step microwave-assisted synthetic route for the fabrication of Mn{sub 3}O{sub 4} nanoparticles@reduced graphene oxide (Mn{sub 3}O{sub 4}@rGO) nanocomposites has been demonstrated. The morphological structures of the nanocomposites are characterized by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analyses (TGA), and scanning electron microscopy (SEM), respectively. All of the results indicate that the microwave-assisted synthesis results in the growth of Mn{sub 3}O{sub 4} and the reduction of graphene oxide simultaneously in ethylene glycol-water system. The specific capacitance of the as-prepared Mn{sub 3}O{sub 4}@rGO nanocomposite is higher than those of rGO and pure Mn{sub 3}O{sub 4}, which indicates the synergetic interaction between rGO and Mn{sub 3}O{sub 4}. The nanocomposites also have good rate capability and cycling stability in electrochemical experiments. This facile technique may be extended to the large scale and cost effective production of other composites based on graphene and metal oxide for many applications.

  12. Synthesis of Carbon–Metal Multi-Strand Nanocomposites by Discharges in Heptane Between Two Metallic Electrodes

    KAUST Repository

    Hamdan, Ahmad; Kabbara, H.; Courty, M.-A.; Cha, Min; Martinez, J.-M.; Belmonte, T.

    2017-01-01

    We studied composite wires assembled from electric field-driven nanoparticles in a dielectric liquid (heptane) to elucidate the exact processes and controlling factors involved in the synthesis of the multi-phase nanocomposites. Filamentary wires

  13. Facile synthesis of Z-scheme graphitic-C{sub 3}N{sub 4}/Bi{sub 2}MoO{sub 6} nanocomposite for enhanced visible photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Jiali [College of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000 (China); Dai, Kai, E-mail: daikai940@chnu.edu.cn [College of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000 (China); Zhang, Jinfeng; Geng, Lei [College of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000 (China); Liang, Changhao, E-mail: chliang@issp.ac.cn [College of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000 (China); Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Qiangchun; Zhu, Guangping; Chen, Chen [College of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000 (China)

    2015-12-15

    Graphical abstract: - Highlights: • g-C{sub 3}N{sub 4}/Bi{sub 2}MoO{sub 6} nanocomposite photocatalyst was prepared. • g-C{sub 3}N{sub 4}/Bi{sub 2}MoO{sub 6} as a typical Z-scheme photocatalyst was proved. • g-C{sub 3}N{sub 4}/Bi{sub 2}MoO{sub 6} showed long reusable life with irradiation of LED light. - Abstract: The band engineering of visible-light-driven photocatalysts is a promising route for harnessing of effective solar energy to perform high chemical reactions and to treat environmental pollution. In this study, two narrow band gap semiconductor nanomaterials, graphitic carbon nitride (g-C{sub 3}N{sub 4}) and Bi{sub 2}MoO{sub 6}, were selected and coupled to form series of g-C{sub 3}N{sub 4}/Bi{sub 2}MoO{sub 6} photocatalysts. Their structure, light absorption wavelength range, charge transport properties and energy level were investigated. Through perfect manipulation of their composition, enhanced photocatalytic activity of the Z-scheme g-C{sub 3}N{sub 4}/Bi{sub 2}MoO{sub 6} photocatalysts with efficient reduction of recombination of photogenerated electrons and holes was achieved. The optimized Z-scheme g-C{sub 3}N{sub 4}/Bi{sub 2}MoO{sub 6} photocatalysts with 25 wt%g-C{sub 3}N{sub 4} showed apparent pseudo-first-order rate constant k{sub app} as high as 0.0688 min{sup −1}, which was 4.8 times and 8.2 times higher than that of g-C{sub 3}N{sub 4} and Bi{sub 2}MoO{sub 6} photocatalyst, respectively.

  14. Nanocomposites: synthesis, structure, properties and new application opportunities

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Cury Camargo

    2009-03-01

    Full Text Available Nanocomposites, a high performance material exhibit unusual property combinations and unique design possibilities. With an estimated annual growth rate of about 25% and fastest demand to be in engineering plastics and elastomers, their potential is so striking that they are useful in several areas ranging from packaging to biomedical applications. In this unified overview the three types of matrix nanocomposites are presented underlining the need for these materials, their processing methods and some recent results on structure, properties and potential applications, perspectives including need for such materials in future space mission and other interesting applications together with market and safety aspects. Possible uses of natural materials such as clay based minerals, chrysotile and lignocellulosic fibers are highlighted. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors of the aerospace, automotive, electronics and biotechnology industries.

  15. High pressure synthesis of zeolite/polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Haines, Julien; Thibaud, Jean-Marc; Rouquette, Jerome; Cambon, Olivier; Di Renzo, Francesco, E-mail: julien.haines@univ-montp2.fr [Institut Charles Gerhardt Montpellier (France); Lee, Arie van der [Institut Europeen des Membranes, Montpellier (France); Scelta, Demetrio; Ceppatelli, Matteo; Dziubek, Kamil; Gorelli, Federico; Bini, Roberto; Santoro, Mario [European Laboratory for Non Linear Spectroscopy, Firenze (Italy)

    2016-07-01

    Full text: Polymerization of simple organic molecules under high pressure in the subnanometric pores of pure SiO{sub 2} zeolites can be used to produce novel nanocomposite materials, which can be recovered at ambient P and have remarkable mechanical, electrical or optical properties. Polymerization of ethylene in silicalite was studied in situ at high pressure by IR and results in a nanocomposite with isolated chains of non-conducting polyethylene strongly confined in the pores based on single crystal x-ray diffraction data. The nanocomposite is much less compressible than silicalite and has a positive rather than a negative thermal expansion coefficient. In order to target novel electrical and optical properties, isolated chains of conducting polymers can also be prepared in the pores of zeolite hosts at high pressure, such as polyacetylene, which was polymerized under pressure in the pores of the 1-D zeolite TON. The structure of this nanocomposite was determined by synchrotron x-ray powder diffraction data with complete pore filling corresponding to one planar polymer chain confined in each pore with a zig-zag configuration in the yz plane. This very strong confinement can be expected to strongly modify the electrical properties of polyacetylene. In this nanocomposite, our theoretical calculations indicate that the electronic density of states of polyacetylene exhibit van Hove singularities related to quantum 1D confinement, which could lead to future technological applications. This new material is susceptible to have applications in nanoelectronics, nanophotonics and energy and light harvesting. Completely novel nanocomposites were prepared by the polymerization of carbon monoxide CO in silicalite and TON. In these materials, isolated, ideal polycarbonyl chains are obtained in contrast to the non-stoichiometric, branched bulk polymers obtained by high pressure polymerization of this simple system. These poly CO/zeolite composites could be interesting energetic

  16. Microwave-assisted synthesis of graphene/CoMoO4 nanocomposites with enhanced supercapacitor performance

    International Nuclear Information System (INIS)

    Xu, Xiaowei; Shen, Jianfeng; Li, Na; Ye, Mingxin

    2014-01-01

    Highlights: • RGO/CoMoO 4 nanocomposites are prepared by microwave irradiation for the first time. • RGO/CoMoO 4 nanocomposites show a high specific capacitance of 322.5 F g −1 . • Enhanced electrical conductivity leads to superior electrochemical performance. • Low crystallinity of CoMoO 4 is favorable to improve the electrochemical performance. - Abstract: A facile and efficient strategy for preparing reduced graphene oxide–cobalt molybdate (RGO/CoMoO 4 ) nanocomposites assisted by microwave irradiation for the first time is demonstrated. The resulting nanocomposites are comprised of CoMoO 4 nanoparticles that are well-anchored on graphene sheets by in situ reducing. The prepared RGO/CoMoO 4 nanocomposites have been thoroughly characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy and X-ray photoelectron spectroscopy. Importantly, the prepared nanocomposites exhibit excellent electrochemical performance for supercapacitors. Results show that RGO/CoMoO 4 nanocomposites exhibited much better electrochemical capability than pure-CoMoO 4 and RGO/CoMoO 4 for annealing. RGO/CoMoO 4 nanocomposites with 37.4 wt% CoMoO 4 content achieved a specific capacitance about 322.5 F g −1 calculated from the CV plots at 5 mV s −1 , which was higher than that of pure-CoMoO 4 (95.0 F g −1 ) and RGO/CoMoO 4 for annealing (102.5 F g −1 ). The good electrochemical performance can be attributed to the synergistic effects of the individual components

  17. A Facile Route to Metal Oxides/Single-Walled Carbon Nanotube Macrofilm Nanocomposites for Energy Storage

    Science.gov (United States)

    Cao, Zeyuan; Wei, Bingqing

    2015-05-01

    Nanocomposites consisting of transition-metal oxides and carbon nanomaterials with a desired size and structure are highly demanded for high performance energy storage devices. Here, a facile two-step and cost-efficient approach relying on directly thermal treatment of chemical-vapor-deposition products is developed as a general synthetic method to prepare a family of metal oxides (MxOy (M=Fe, Co, Ni))/single-walled carbon nanotube (SWNT) macrofilm nanocomposites. The MxOy nanoparticles obtained are of 3-17 nm in diameter and homogeneously anchor on the free-standing SWNT macrofilms. NiO/SWNT also exhibits a high specific capacitance of 400 F g-1 and fast charge-transfer Faradaic redox reactions to achieve asymmetric supercapacitors with a high power and energy density. All MxOy/SWNT nanocomposites could deliver a high capacity beyond 1000 mAh g-1 and show excellent cycling stability for lithium-ion batteries. The impressive results demonstrate the promise for energy storage devices and the general approach may pave the way to synthesize other functional nanocomposites.

  18. A Facile Route to Metal Oxides/Single-Walled Carbon Nanotube Macrofilm Nanocomposites for Energy Storage

    Directory of Open Access Journals (Sweden)

    Zeyuan eCao

    2015-05-01

    Full Text Available Nanocomposites consisting of transition-metal oxides and carbon nanomaterials with a desired size and structure are highly demanded for high performance energy storage devices. Here, a facile two-step and cost-efficient approach relying on directly thermal treatment of chemical-vapor-deposition products is developed as a general synthetic method to prepare a family of metal oxides (MxOy (M=Fe, Co, Ni/single-walled carbon nanotube (SWNT macrofilm nanocomposites. The MxOy nanoparticles obtained are of 3-17 nm in diameter and homogeneously anchor on the free-standing SWNT macrofilms. NiO/SWNT also exhibits a high specific capacitance of 400 F g-1 and fast charge-transfer Faradaic redox reactions to achieve asymmetric supercapacitors with a high power and energy density. All MxOy/SWNT nanocomposites could deliver a high capacity beyond 1000 mAh g-1 and show excellent cycling stability for lithium-ion batteries. The impressive results demonstrate the promise for energy storage devices and the general approach may pave the way to synthesize other functional nanocomposites.

  19. Synthesis of antimicrobial silver/hydroxyapatite nanocomposite by gamma irradiation

    International Nuclear Information System (INIS)

    Akhavan, A.; Sheikh, N.; Khoylou, F.; Naimian, F.; Ataeivarjovi, E.

    2014-01-01

    Silver nanoparticles (AgNPs) were synthesized through γ-irradiation reduction of silver ions into hydroxyapatite as a solid support. The formation of AgNPs incorporated in the hydroxyapatite composite was studied as a function of γ-irradiation doses. The X-ray diffraction and transmission electron microscopy (TEM) measurements showed the fabrication of face-centered cubic AgNPs with a mean diameter of about 39 nm at 20 kGy absorbed dose. When the absorbed dose increases from 20 to 40 kGy the size of AgNPs particles partially increases, while with increasing absorbed dose from 40 to 60 kGy the particle diameters decreases. In addition, the results of XRD analysis indicated that increasing of γ-irradiation doses from 20 to 40 kGy enhances the concentration of AgNPs, without inducing significant changes in degree of HA crystallinity. The antibacterial test study of samples against Escherichia coli indicated a significant enhancement in the antibacterial property of Ag/HA nanocomposites. - Highlights: • Silver/hydroxyapatite nanocomposites are synthesized through γ-irradiation method. • Ag/HA nanocomposites have good antibacterial properties. • Fabricated pure nanocomposites are suitable for medical and dental applications

  20. Synthesis and characterization of polyaniline coated gold nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Zuber, Siti Nurzulaiha Mohd; Kamarun, Dzaraini; Zaki, Hamizah; Kamarudin, Mohamad Shukri [Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Shah Alam, 40450 Selangor Darul Ehsan (Malaysia); Thomas, Sabu; Kalarikkal, Nandakumar [International and Inter University Centre of Nanoscience and Nanotechnoogy, Mahatma Ghandi University, Priyadarsini Hills Kottayam, Kerala India-686560 (India)

    2015-08-28

    Considerable attention has been drawn during the last two decades to prepare nanocomposites consists of conducting polymer and noble metal due to their potential ability to generate a new class of material with novel optical, chemical, electronic or mechanical properties for various applications. In this work, an attempt has been made to synthesize nanocomposite of polyaniline (PANI) coated with gold nanoparticles (AuNPs) chemically with various types of surfactants such as polyvinylpyrrolidone (PVP), and sodium dodecyl sulphate (SDS) which act as stabilizing agents to help in stabilization of the PANI/Gold nanocomposites system. The synthesized nanocomposites were characterized by UV-Visible, field emission scanning electron microscope (FESEM) and particle size analyzer (PSA). The formation of finger like structure can be seen in the FESEM images when the AuNPs were incorporated into the polymer matrix. The EDX data showed that 18.66% and 12.67% of AuNPs atoms were present in the composite system thus proved the incorporation of AuNPs into the polymer matrix. A small red shift of the absorption peak in the UV-Vis of both PANI/AuNPs composites system may be due to the incorporation of AuNPs in the PANI matrix.

  1. Synthesis and characterization of polyaniline coated gold nanocomposites

    International Nuclear Information System (INIS)

    Zuber, Siti Nurzulaiha Mohd; Kamarun, Dzaraini; Zaki, Hamizah; Kamarudin, Mohamad Shukri; Thomas, Sabu; Kalarikkal, Nandakumar

    2015-01-01

    Considerable attention has been drawn during the last two decades to prepare nanocomposites consists of conducting polymer and noble metal due to their potential ability to generate a new class of material with novel optical, chemical, electronic or mechanical properties for various applications. In this work, an attempt has been made to synthesize nanocomposite of polyaniline (PANI) coated with gold nanoparticles (AuNPs) chemically with various types of surfactants such as polyvinylpyrrolidone (PVP), and sodium dodecyl sulphate (SDS) which act as stabilizing agents to help in stabilization of the PANI/Gold nanocomposites system. The synthesized nanocomposites were characterized by UV-Visible, field emission scanning electron microscope (FESEM) and particle size analyzer (PSA). The formation of finger like structure can be seen in the FESEM images when the AuNPs were incorporated into the polymer matrix. The EDX data showed that 18.66% and 12.67% of AuNPs atoms were present in the composite system thus proved the incorporation of AuNPs into the polymer matrix. A small red shift of the absorption peak in the UV-Vis of both PANI/AuNPs composites system may be due to the incorporation of AuNPs in the PANI matrix

  2. Synthesis, characterization and impedance spectroscopy study of magnetite/epoxidized natural rubber nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Tan, W.L. [Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, M., E-mail: bmohamad@usm.my [Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2013-06-05

    Highlights: ► The Fe{sub 3}O{sub 4}/ENR nanocomposites have not been synthesized and reported. ► Nanocomposites were obtained via in situ synthesis of Fe{sub 3}O{sub 4} in the presence of ENR. ► The use of ENR enabled control of the size of Fe{sub 3}O{sub 4} particles to <20 nm. ► Conductivity of the nanocomposites increases with the increase in Fe{sub 3}O{sub 4} loading. ► The equivalent circuit for the nanocomposites is proposed and discussed. -- Abstract: The magnetite (Fe{sub 3}O{sub 4}) particles were synthesized in situ in the presence of epoxidized natural rubber (ENR) to produce the various Fe{sub 3}O{sub 4}/ENR nanocomposites. The X-ray diffraction (XRD) analysis confirmed the existence of Fe{sub 3}O{sub 4} particles in the composites. The FTIR and DSC studies suggested that no chemical interactions between the particles and the matrix. The SEM and X-mapping micrographs revealed that the Fe{sub 3}O{sub 4} particles were distributed within the ENR matrix. The ENR matrix exerts control on the Fe{sub 3}O{sub 4} particles with a size of <20 nm in the composites. The Fe{sub 3}O{sub 4} particles also affect the electrical properties of the composites. Impedance spectroscopy studies show that the electrical conductivity of the nanocomposites increases with the increase in Fe{sub 3}O{sub 4} loading in the composite. The equivalent circuit for the Fe{sub 3}O{sub 4}/ENR nanocomposites is proposed and discussed.

  3. Room temperature synthesis of water-repellent polystyrene nanocomposite coating

    International Nuclear Information System (INIS)

    Guo Yonggang; Jiang Dong; Zhang Xia; Zhang Zhijun; Wang Qihua

    2010-01-01

    A stable superhydrophobic polystyrene nanocomposite coating was fabricated by means of a very simple and easy method. The coating was characterized by scanning electron microscopy and X-ray photoelectron spectrum. The wettability of the products was also investigated. By adding the surface-modified SiO 2 nanoparticles, the wettability of the coating changed to water-repellent superhydrophobic, not only for pure water, but also for a wide pH range of corrosive liquids. The influence of the drying temperature and SiO 2 content on the wettability of the nanocomposite coating was also investigated. It was found that both factors had little or no significant effect on the wetting behavior of the coating surface.

  4. Synthesis and characterization of rubbery epoxy/organoclay hectorite nanocomposites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available The present research investigates the morphology, the mechanical, and the viscoelastic properties of rubbery epoxy/clay nanocomposites synthesized by in situ polymerisation of a prepolymer diglycidyl ether of bisphenol-A crosslinked with an aliphatic diamine based on a polyoxypropylene backbone. The inorganic phase was hectorite, exchanged with octadecylammonium ions in order to give organophilic properties to the phyllosilicate. An ultrasonicator was used to disperse the silicate clay layer into epoxy-amine matrix. The morphology of epoxy-hectorite nanocomposites examined by transmission electron microscopy (TEM showed that mixed delamination or intercalation or microdispersion could occur depending on type of organoclay. Moreover, the mechanical and viscoelastic properties were found to be improved with only the treated hectorite.

  5. Synthesis and characterization of optically transparent epoxy matrix nanocomposites

    International Nuclear Information System (INIS)

    Esposito Corcione, C.; Manera, M.G.; Maffezzoli, A.; Rella, R.

    2009-01-01

    In this work optically transparent nanocomposites were prepared and characterized from an optical and morphological point of view. An organically modified boehmite was added at different concentrations in a diglycidyl ether of bisphenol A (DGEBA) epoxy matrix, hardened with a polyether diamine. Nanocomposites were characterized structurally by X-ray diffraction (XRD), optically by UV-Vis-NIR spectrophotometry and their morphology was investigated by Atomic Force Microscopy (AFM). Morphological investigation reveals the presence of boehmite particles dispersed in the epoxy matrix in different dimensions ranging from ten to hundreds of nanometers; some aggregation in the particles is the tendency noticed in the AFM images. The acquisition of multiple AFM images in different areas of the sample was used for a statistical analysis of the volumetric distribution of boehmite aggregates. The obtained result, (3.6 ± 0.3)%vol, is well comparable to thermogravimetric analysis.

  6. Synthesis and characterization of HDPE/N-MWNT nanocomposite films.

    Science.gov (United States)

    Chouit, Fairouz; Guellati, Ounassa; Boukhezar, Skander; Harat, Aicha; Guerioune, Mohamed; Badi, Nacer

    2014-01-01

    In this work, a series of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) with several weight percentages (0.1, 0.4, 0.8, and 1.0 wt.%) were synthesized by catalytic chemical vapor deposition (CCVD) technique. The N-MWCNTs were first characterized and then dispersed in high-density polyethylene (HDPE) polymer matrix to form a nanocomposite. The HDPE/N-MWCNT nanocomposite films were prepared by melt mixing and hot pressing; a good dispersion in the matrix and a good N-MWCNT-polymer interfacial adhesion have been verified by scanning electron microscopy (SEM). Raman spectroscopy measurements have been performed on prepared samples to confirm the presence and nature of N-MWNTs in HDPE matrix. The X-ray diffraction (XRD) analysis demonstrated that the crystalline structure of HDPE matrix was not affected by the incorporation of the N-MWNTs.

  7. Synthesis and photocatalytic activity of graphene based doped TiO2 nanocomposites

    International Nuclear Information System (INIS)

    Gu, Yongji; Xing, Mingyang; Zhang, Jinlong

    2014-01-01

    Graphical abstract: - Highlights: • Graphene based doped TiO 2 nanocomposites were prepared. • The intimate contact between doped TiO 2 and graphene is achieved simultaneously. • These nanocomposites showed higher photocatalytic activity than TiO 2 and doped TiO 2 . • Photocatalytic mechanism was explained thoroughly. - Abstract: The nanocomposites of reduced graphene oxide based nitrogen doped TiO 2 (N–TiO 2 –RGO) and reduced graphene oxide based nitrogen and vanadium co-doped TiO 2 (N, V–TiO 2 –RGO) were prepared via a facile hydrothermal reaction of graphene oxide and TiO 2 in a water solvent. In this hydrothermal treatment, the reduction of graphene oxide and the intimate contact between nitrogen doped TiO 2 (N–TiO 2 ) or nitrogen and vanadium co-doped TiO 2 (N,V–TiO 2 ) and the RGO sheet is achieved simultaneously. Both N–TiO 2 –RGO and N,V–TiO 2 –RGO nanocomposites exhibit much higher visible light photocatalytic activity than N–TiO 2 and N,V–TiO 2 , and the order of visible light photocatalytic activity is N,V–TiO 2 –RGO > N–TiO 2 –RGO > N,V–TiO 2 > N–TiO 2 > TiO 2 . According to the characterization, the enhanced photocatalytic activity of the nanocomposites is attributed to reasons, such as enhancement of adsorption of pollutants, light absorption intensity, minimizing the recombination of photoinduced electrons and holes and more excited states of these nanocomposites under visible light irradiation. Overall, this work provides a more marked contrast of graphene based semiconductor nanocomposites and a more comprehensive explanation of the mechanism

  8. Synthesis and morphology of hydroxyapatite/polyethylene oxide nanocomposites with block copolymer compatibilized interfaces

    Science.gov (United States)

    Lee, Ji Hoon; Shofner, Meisha

    2012-02-01

    In order to exploit the promise of polymer nanocomposites, special consideration should be given to component interfaces during synthesis and processing. Previous results from this group have shown that nanoparticles clustered into larger structures consistent with their native shape when the polymer matrix crystallinity was high. Therefore in this research, the nanoparticles are disguised from a highly-crystalline polymer matrix by cloaking them with a matrix-compatible block copolymer. Specifically, spherical and needle-shaped hydroxyapatite nanoparticles were synthesized using a block copolymer templating method. The block copolymer used, polyethylene oxide-b-polymethacrylic acid, remained on the nanoparticle surface following synthesis with the polyethylene oxide block exposed. These nanoparticles were subsequently added to a polyethylene oxide matrix using solution processing. Characterization of the nanocomposites indicated that the copolymer coating prevented the nanoparticles from assembling into ordered clusters and that the matrix crystallinity was decreased at a nanoparticle spacing of approximately 100 nm.

  9. Synthesis of EVA/MWNT nanocomposites by radiation induced crosslinking

    International Nuclear Information System (INIS)

    Dubey, K.A.; Bhardwaj, Y.K.; Chaudhari, C.V.; Sabharwal, S.

    2008-01-01

    Full text: EVA is widely used as an insulating material for high voltage cables and in the footwear and toy industries due to its high flexibility and chemical inertness. The nano-composites of EVA with MWNT are of the special interest because incorporation of suitable amount of MWNT in EVA matrix is expected to significantly enhance EVA's thermal and mechanical properties, and open a new domain of applications. The modification of EVA by using high-energy radiation and with particulate filler has been widely practiced; however, there is not much information available on the radiation processing of EVA nanocomposites. To understand the effect of radiation and of MWNT addition on the physico-mechanical characteristics of EVA, different compositions of ethylene vinyl acetate (EVA)/multiple walled carbon nanotube (MWNT) nanocomposites were prepared by mixing in Brabender and subjected to different doses of gamma radiation. The efficiency of radiation vulcanization was analyzed by gel-content, Charlesby-Pinner parameter and crosslinking density measurements. Gamma radiation induced crosslinking was found to increase with MWNT fraction in EVA/MWNT nanocomposites (P o /q o range: 1.15-0.98). These results ruled out the possibility of a significant neutralization of single ionization spurs by MWNT addition. The polymer-filler interaction parameter determined from Kraus plot indicated good interaction between EVA and MWNTs. Storage modulus changed from 7 x 10 7 Pa to 1.8 x 10 8 Pa with incorporation of 5% (wt/wt) MWNT while density increased from 0.78 g/cc to 0.80 g/cc

  10. Synthesis of a nanocomposite biomaterial for implant tissue engineering

    OpenAIRE

    Santos Montes, Angélica

    2015-01-01

    In order to improve health and quality of life, the challenge to develop new biomaterials has become extremely relevant. In this project, our main objective is to obtain a nanocomposite biopolymer that serves as a temporal synthetic extracellular matrix for cell growth and tissue regeneration. This matrix consists of a hydrogel lm of chitosan or agarose doped with di erent ceramic nanoparticles: titanium dioxide (TiO2) and aluminum oxide (Al2O3). Once developed, this composite will be tested...

  11. A facile method to prepare superhydrophobic fluorinated polysiloxane/ZnO nanocomposite coatings with corrosion resistance

    Science.gov (United States)

    Qing, Yongquan; Yang, Chuanning; Hu, Chuanbo; Zheng, Yansheng; Liu, Changsheng

    2015-01-01

    In this paper, we report a simple and inexpensive method for fabricating fluorinated polysiloxane/ZnO nanocomposite coatings on the steel substrates. The surface wettability and topology of coating were characterized by contact angle measurement, scanning electron microscope and Fourier transform infrared spectrometry. The results showed that the hydrophobic sbnd CH3 and sbnd CH2sbnd groups were introduced into ZnO particles via modification, the ZnO nanoparticles were modified from hydrophilic to hydrophobic. When the weight ratio of modified-ZnO to fluorinated polysiloxane was 13:7, the contact angle of nanocomposite coating was 166°, and a sliding angle of 4°, coating surface with hierarchical micro/nano-structures. In addition, the as-prepared superhydrophobic surface has excellent durability and corrosion resistance. It is believed that the facile and low-cost method offer an effective strategy and promising industrial applications for fabricating superhydrophobic surfaces on steel materials.

  12. Manufacturing Demonstration Facility: Low Temperature Materials Synthesis

    International Nuclear Information System (INIS)

    Graham, David E.; Moon, Ji-Won; Armstrong, Beth L.; Datskos, Panos G.; Duty, Chad E.; Gresback, Ryan; Ivanov, Ilia N.; Jacobs, Christopher B.; Jellison, Gerald Earle; Jang, Gyoung Gug; Joshi, Pooran C.; Jung, Hyunsung; Meyer, Harry M.; Phelps, Tommy

    2015-01-01

    The Manufacturing Demonstration Facility (MDF) low temperature materials synthesis project was established to demonstrate a scalable and sustainable process to produce nanoparticles (NPs) for advanced manufacturing. Previous methods to chemically synthesize NPs typically required expensive, high-purity inorganic chemical reagents, organic solvents and high temperatures. These processes were typically applied at small laboratory scales at yields sufficient for NP characterization, but insufficient to support roll-to-roll processing efforts or device fabrication. The new NanoFermentation processes described here operated at a low temperature (~60 C) in low-cost, aqueous media using bacteria that produce extracellular NPs with controlled size and elemental stoichiometry. Up-scaling activities successfully demonstrated high NP yields and quality in a 900-L pilot-scale reactor, establishing this NanoFermentation process as a competitive biomanufacturing strategy to produce NPs for advanced manufacturing of power electronics, solid-state lighting and sensors.

  13. Facile Synthesis of Ternary Boron Carbonitride Nanotubes

    Directory of Open Access Journals (Sweden)

    Luo Lijie

    2009-01-01

    Full Text Available Abstract In this study, a novel and facile approach for the synthesis of ternary boron carbonitride (B–C–N nanotubes was reported. Growth occurred by heating simple starting materials of boron powder, zinc oxide powder, and ethanol absolute at 1150 °C under a mixture gas flow of nitrogen and hydrogen. As substrate, commercial stainless steel foil with a typical thickness of 0.05 mm played an additional role of catalyst during the growth of nanotubes. The nanotubes were characterized by SEM, TEM, EDX, and EELS. The results indicate that the synthesized B–C–N nanotubes exhibit a bamboo-like morphology and B, C, and N elements are homogeneously distributed in the nanotubes. A catalyzed vapor–liquid–solid (VLS mechanism was proposed for the growth of the nanotubes.

  14. Manufacturing Demonstration Facility: Low Temperature Materials Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Graham, David E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moon, Ji-Won [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Armstrong, Beth L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Datskos, Panos G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duty, Chad E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gresback, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ivanov, Ilia N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jacobs, Christopher B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jellison, Gerald Earle [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jang, Gyoung Gug [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Joshi, Pooran C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jung, Hyunsung [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Meyer, III, Harry M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Phelps, Tommy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-06-30

    The Manufacturing Demonstration Facility (MDF) low temperature materials synthesis project was established to demonstrate a scalable and sustainable process to produce nanoparticles (NPs) for advanced manufacturing. Previous methods to chemically synthesize NPs typically required expensive, high-purity inorganic chemical reagents, organic solvents and high temperatures. These processes were typically applied at small laboratory scales at yields sufficient for NP characterization, but insufficient to support roll-to-roll processing efforts or device fabrication. The new NanoFermentation processes described here operated at a low temperature (~60 C) in low-cost, aqueous media using bacteria that produce extracellular NPs with controlled size and elemental stoichiometry. Up-scaling activities successfully demonstrated high NP yields and quality in a 900-L pilot-scale reactor, establishing this NanoFermentation process as a competitive biomanufacturing strategy to produce NPs for advanced manufacturing of power electronics, solid-state lighting and sensors.

  15. Green synthesis of AgI-reduced graphene oxide nanocomposites: Toward enhanced visible-light photocatalytic activity for organic dye removal

    International Nuclear Information System (INIS)

    Reddy, D. Amaranatha; Lee, Seunghee; Choi, Jiha; Park, Seonhwa; Ma, Rory; Yang, Haesik; Kim, Tae Kyu

    2015-01-01

    Graphical abstract: - Highlights: • A novel green synthesis of AgI-RGO nanocomposites. • Significant improvement of the photocatalytic activity in RGO wrapped composites. • Additive promoted photocatalytic performance in AgI-RGO composites. • AgI-RGO nanocomposites may find applications in luminescent and catalytic devices. - Abstract: Novel reduced graphene oxide (RGO) enwrapped AgI nanocomposites were successfully fabricated by a facile template-free ultrasound-assisted method at room temperature. The structural, morphological, and optical studies demonstrate that the obtained nanostructures have good crystallinity and that the graphene nanosheets are decorated densely with AgI nanostructures. The photocatalytic activity of the composite was evaluated by the degradation of an organic dye, Rhodamine B (RhB), under visible-light irradiation. The results indicate that AgI with incorporated graphene exhibited much higher photocatalytic activity than the pure AgI due to the improved separation efficiency of the photogenerated carriers and that it prolonged the lifetime of the electron–hole pairs due to the chemical bonding between AgI and graphene. AgI (0.4 mg mL −1 of graphene oxide) nanocomposites displayed the highest photocatalytic degradation efficiency and the corresponding catalytic efficiencies within 70 min were ∼96%. Moreover, with the assistance of H 2 O 2 the photocatalytic ability of the as-obtained AgI-RGO nanocomposites was enhanced. The corresponding catalytic efficiencies within 30 min were ∼96.8% (for 1 mL H 2 O 2 ) under the same irradiation conditions. The excellent visible-light photocatalytic efficiency and luminescence properties make the AgI-RGO nanocomposites promising candidates for the removal of organic dyes for water purification and enable their application in near-UV white LEDs

  16. Structural Ceramic Nanocomposites: A Review of Properties and Powders’ Synthesis Methods

    Science.gov (United States)

    Palmero, Paola

    2015-01-01

    Ceramic nanocomposites are attracting growing interest, thanks to new processing methods enabling these materials to go from the research laboratory scale to the commercial level. Today, many different types of nanocomposite structures are proposed in the literature; however, to fully exploit their exceptional properties, a deep understanding of the materials’ behavior across length scales is necessary. In fact, knowing how the nanoscale structure influences the bulk properties enables the design of increasingly performing composite materials. A further key point is the ability of tailoring the desired nanostructured features in the sintered composites, a challenging issue requiring a careful control of all stages of manufacturing, from powder synthesis to sintering. This review is divided into four parts. In the first, classification and general issues of nanostructured ceramics are reported. The second provides basic structure–property relations, highlighting the grain-size dependence of the materials properties. The third describes the role of nanocrystalline second-phases on the mechanical properties of ordinary grain sized ceramics. Finally, the fourth part revises the mainly used synthesis routes to produce nanocomposite ceramic powders, underlining when possible the critical role of the synthesis method on the control of microstructure and properties of the sintered ceramics. PMID:28347029

  17. Facile synthesis of nanorod-type graphitic carbon nitride/Fe2O3 composite with enhanced photocatalytic performance

    International Nuclear Information System (INIS)

    Wang, Jiangpeng; Li, Changqing; Cong, Jingkun; Liu, Ziwei; Zhang, Hanzhuo; Liang, Mei; Gao, Junkuo; Wang, Shunli; Yao, Juming

    2016-01-01

    Here we report a facile synthesis of nanorod-type graphitic carbon nitride/Fe 2 O 3 composite (Fe 2 O 3 -g-C 3 N 4 ) by using Fe-melamine supramolecular framework as precursor. The chemical and optical properties of the nanocomposites are well-characterized. The Fe 2 O 3 -g-C 3 N 4 nanocomposite demonstrated excellent photocatalytic activities under visible light due to the efficient utilization of sunlight and the construction of Z-scheme electron transfer pathway. The results indicated that it could be a promising approach for the preparation of efficient g-C 3 N 4 nanocomposites photocatalysts by using metal-melamine supramolecular framework as precursors. - Graphical abstract: Nanorod-type graphitic carbon nitride/Fe 2 O 3 composite (Fe 2 O 3 -g-C 3 N 4 ) was synthesized by using Fe-melamine supramolecular framework as precursor. The Fe 2 O 3 -g-C 3 N 4 nanocomposite demonstrated excellent photocatalytic activities under visible light. Display Omitted - Highlights: • Nanorod-type graphitic carbon nitride/Fe 2 O 3 composite (Fe 2 O 3 -g-C 3 N 4 ) was synthesized. • Fe 2 O 3 -g-C 3 N 4 showed strong optical absorption in the visible-light region. • The Fe 2 O 3 -g-C 3 N 4 nanocomposite demonstrated excellent photocatalytic activities.

  18. Novel synthesis of magnesium hydroxide nanoparticles modified with organic phosphate and their effect on the flammability of acrylonitrile-butadiene styrene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Attia, Nour F., E-mail: drnour2005@yahoo.com [Fire Protection Laboratory, Chemistry Division, National Institute of Standards, 136, Giza 12211 (Egypt); Goda, Emad S.; Nour, M.A. [Fire Protection Laboratory, Chemistry Division, National Institute of Standards, 136, Giza 12211 (Egypt); Sabaa, M.W. [Chemistry Department, Faculty of Science, Cairo University, NahdetMisr Street, Giza 12613 (Egypt); Hassan, M.A., E-mail: Mohamed_a_hassan@hotmail.com [Fire Protection Laboratory, Chemistry Division, National Institute of Standards, 136, Giza 12211 (Egypt)

    2015-11-15

    New and facile method for the synthesis and modification of magnesium hydroxide nanoparticles has been developed. The organic phosphate was used to facilitate the synthesis and wrapping of magnesium hydroxide nanoparticles with organic phosphate shell. The size of the nanoparticles wrapped with phosphate has an average diameter range from 46 to 125 nm. The preparation method has governed the nanoparticles diameter based on reaction time. Thermal stability and morphological properties of the new nanoparticles coated phosphates were investigated. The developed magnesium hydroxide nanoparticles-organic phosphate achieved a very good compatibility when dispersed in acrylonitrile-butadiene styrene polymer (ABS) produced dispersed nanocomposites. The flammability and thermal properties of the new polymer nanocomposites were studied. The rate of burning of the nanocomposites was reduced to 9.8 mm/min compared to 15, 21.9 and 42.5 mm/min for polymer-conventional magnesium hydroxide composite, polymer-conventional magnesium hydroxide-organic phosphate composite and virgin polymer, respectively. The peak heat release rate (PHRR) and total heat release (THR) of the new nanocomposites were recorded as 243.4 kW/m{sup 2} and 19.2 MJ/m{sup 2}, respectively, achieved 71% reduction for PHRR and 55% for THR. The synergism between magnesium hydroxide nanoparticles and organic phosphates shell was also studied. The developed nanoparticles suppressed the emission of toxic gases. The different materials were characterized using thermal gravimetric analysis, fourier transform infrared spectroscopy, transmission electron microscopy. The flammability properties were evaluated using UL94 horizontal method and cone calorimeter. The dispersion of magnesium hydroxide nanoparticles-organic phosphate in ABS was studied using scanning electron microscope. - Highlights: • Novel and facile nanoparticles synthesis and modification have developed. • Magnesium hydroxide nanoparticles size has

  19. Survey of current trends in DNA synthesis core facilities.

    Science.gov (United States)

    Hager, K M; Fox, J W; Gunthorpe, M; Lilley, K S; Yeung, A

    1999-12-01

    The Nucleic Acids Research Group of the Association of Biomolecular Resource Facilities (ABRF) last surveyed DNA synthesis core facilities in April 1995. Because of the introduction of new technologies and dramatic changes in the market, we sought to update survey information and to determine how academic facilities responded to the challenge presented by commercial counterparts. The online survey was opened in January 1999 by notifying members and subscribers to the ABRF electronic discussion group. The survey consisted of five parts: general facility information, oligonucleotide production profile, oligonucleotide charges, synthesis protocols, and trends in DNA synthesis (including individual comments). All submitted data were anonymously coded. Respondents from DNA synthesis facilities were primarily from the academic category and were established between 1984 and 1991. Typically, a facility provides additional services such as DNA sequencing and has upgraded to electronic ordering. There is stability in staffing profiles for these facilities in that the total number of employees is relatively unchanged, the tenure for staff averages 5.9 years, and experience is extensive. On average, academic facilities annually produce approximately 1/16 the number of oligonucleotides produced by the average commercial facilities, but all facilities report an increase in demand. Charges for standard oligonucleotides from academic facilities are relatively higher than from commercial companies; however, the opposite is true for modified phosphoramidites. Subsidized facilities charge less than nonsubsidized facilities. Synthesis protocols and reagents are standard across the categories. Most facilities offer typical modifications such as biotinylation. Despite the competition by large commercial facilities that have reduced costs dramatically, academic facilities remain a stable entity. Academic facilities enhance the quality of service by focusing on nonstandard

  20. Facile preparation of PbS nanostructures and PbS/f-CNT nanocomposites using xanthate as sulfur source: Thermal and optical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Golabi, Parisa; Akbarzadeh, Raziyeh; Dehghani, Hossein, E-mail: dehghani@kashanu.ac.ir

    2015-10-25

    PbS nanostructures with different morphologies were fabricated using a new sulfur source through a facile and low cost hydro(solvo)thermal method. The influence of different reaction factors such as sulfur source, temperature, reactant, solvent and surfactant on the size and morphology of the obtained PbS particles were investigated. Beside, a simple hydrothermal process at low temperature (60 °C) for little time (4 h), has been used for preparation of PbS nanoparticles (NPs)/functionalized multi wall carbon nanotubes (f-MWCNTs) nanocomposite. The as-prepared nanocomposite possesses excellent thermal and optical properties. Thermal stability increases by depositing PbS nanoparticles on the surface of CNT. The structure, morphology, thermal and optical properties of the as-prepared nanocompounds were studied by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy, Thermogravimetric analysis (TGA), Pl spectra and UV–Vis absorption spectra. Photoluminescence spectra of PbS NPs and nanocomposite are consist of two emission peaks which centered at around 402 and 423 nm, when excited at 350 nm. It was noteworthy that the blue luminescence intensity over PbS/f-CNT nanocomposite is very lower than that of pure PbS NPs. Remarkable blue-shift from bulk material was observed on the PbS nanoparticles using UV–Vis spectrum. Furthermore, possible growth mechanism of PbS nanostructures is presented. - Graphical abstract: PbS nanostructures with different morphologies were fabricated using xanthate as sulfide source. Also, PbS/f-CNT nanocomposites were synthesized by simple hydrothermal process at low temperature (60 °C) for little time (4 h). - Highlights: • Sodium tert-butyl xanthate was used as sulfur source for synthesis of PbS. • Pb(CH{sub 3}COO){sub 2}·3H{sub 2}O salt was used for synthesis of PbS. • PbS/CNT nanocomposite was synthesized in deionized water for 4 h at 60

  1. One-pot synthesis and transfer of PMMA/Ag photonic nanocomposites by pulsed laser deposition

    Science.gov (United States)

    Karoutsos, V.; Koutselas, I.; Orfanou, P.; Mpatzaka, Th.; Vasileiadis, M.; Vassilakopoulou, A.; Vainos, N. A.; Perrone, A.

    2015-08-01

    Nanocomposite films comprising metallic nanoparticles in polymer matrices find increasing use in emerging photonic, electronic and microsystem applications owing to their tailored advanced functionalities. The versatile development of such films based on poly-methyl-methacrylate (PMMA) matrix having embedded Ag nanoparticles is addressed here. Two low-cost one-pot chemical methods for the synthesis of bulk target nanocomposite materials are demonstrated. These nanocomposites are subsequently transferred via pulsed laser deposition using 193 nm ArF excimer laser radiation, producing films maintaining the structural and functional properties. Both target- and laser-deposited materials have been thoroughly characterized using microscopic, spectroscopic and thermal analysis methods. Infrared spectra demonstrated the close molecular PMMA chain similarity for both target and film materials, though structural alterations identified by thermal analysis proved the enhanced characteristics of films grown. High-resolution electron microscopy proved the transfer of Ag nanoparticles sized 10-50 nm. Visible absorption peaked in the spectral range of 430-440 nm and attributed to the Ag nanocomposite plasmonic response verifying the transfer of the functional performance from target to film.

  2. CdS/ZnS nanocomposites: from mechanochemical synthesis to cytotoxicity issues

    International Nuclear Information System (INIS)

    Baláž, Peter; Baláž, Matej; Dutková, Erika; Zorkovská, Anna; Kováč, Jaroslav; Hronec, Pavol; Kováč, Jaroslav; Čaplovičová, Mária; Mojžiš, Ján; Mojžišová, Gabriela; Eliyas, Alexander; Kostova, Nina G.

    2016-01-01

    CdS/ZnS nanocomposites have been prepared by a two-step solid-state mechanochemical synthesis. CdS has been prepared from cadmium acetate and sodium sulfide precursors in the first step. The obtained cubic CdS (hawleyite, JCPDS 00-010-0454) was then mixed in the second step with the cubic ZnS (sphalerite, JCPDS 00-005-0566) synthesized mechanochemically from the analogous precursors. The crystallite sizes of the new type CdS/ZnS nanocomposite, calculated based on the XRD data, were 3–4 nm for both phases. The synthesized nanoparticles have been further characterized by high-resolution transmission electron microscopy (HRTEM) and micro-photoluminescence (μPL) spectroscopy. The PL emission peaks in the PL spectra are attributed to the recombination of holes/electrons in the nanocomposites occurring in depth associated with Cd, Zn vacancies and S interstitials. Their photocatalytic activity was also measured. In the photocatalytic activity tests to decolorize Methyl Orange dye aqueous solution, the process is faster and its effectivity is higher when using CdS/ZnS nanocomposite, compared to single phase CdS. Very low cytotoxic activity (high viability) of the cancer cell lines (selected as models of living cells) has been evidenced for CdS/ZnS in comparison with CdS alone. This fact is in a close relationship with Cd(II) ions dissolution tested in a physiological solution. The concentration of cadmium dissolved from CdS/ZnS nanocomposites with variable Cd:Zn ratio was 2.5–5.0 μg.mL"−"1, whereas the concentration for pure CdS was much higher — 53 μg.ml"−"1. The presence of ZnS in the nanocrystalline composite strongly reduced the release of cadmium into the physiological solution, which simulated the environment in the human body. The obtained CdS/ZnS quantum dots can serve as labeling media and co-agents in future anti-cancer drugs, because of their potential in theranostic applications. - Highlights: • CdS/ZnS nanocomposites with crystallite size 3–4

  3. CdS/ZnS nanocomposites: from mechanochemical synthesis to cytotoxicity issues

    Energy Technology Data Exchange (ETDEWEB)

    Baláž, Peter; Baláž, Matej [Institute of Geotechnics, Slovak Academy of Sciences, 04001 Košice (Slovakia); Dutková, Erika, E-mail: dutkova@saske.sk [Institute of Geotechnics, Slovak Academy of Sciences, 04001 Košice (Slovakia); Zorkovská, Anna [Institute of Geotechnics, Slovak Academy of Sciences, 04001 Košice (Slovakia); Kováč, Jaroslav; Hronec, Pavol; Kováč, Jaroslav [Institute of Electronics and Photonics, Slovak University of Technology and International Laser Centre, 81219 Bratislava (Slovakia); Čaplovičová, Mária [STU Centre for Nanodiagnostics, Slovak University of Technology, Vazovova 5, 812 43 Bratislava (Slovakia); Mojžiš, Ján; Mojžišová, Gabriela [Faculty of Medicine, P. J. Šafárik University, 04011 Košice (Slovakia); Eliyas, Alexander; Kostova, Nina G. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2016-01-01

    CdS/ZnS nanocomposites have been prepared by a two-step solid-state mechanochemical synthesis. CdS has been prepared from cadmium acetate and sodium sulfide precursors in the first step. The obtained cubic CdS (hawleyite, JCPDS 00-010-0454) was then mixed in the second step with the cubic ZnS (sphalerite, JCPDS 00-005-0566) synthesized mechanochemically from the analogous precursors. The crystallite sizes of the new type CdS/ZnS nanocomposite, calculated based on the XRD data, were 3–4 nm for both phases. The synthesized nanoparticles have been further characterized by high-resolution transmission electron microscopy (HRTEM) and micro-photoluminescence (μPL) spectroscopy. The PL emission peaks in the PL spectra are attributed to the recombination of holes/electrons in the nanocomposites occurring in depth associated with Cd, Zn vacancies and S interstitials. Their photocatalytic activity was also measured. In the photocatalytic activity tests to decolorize Methyl Orange dye aqueous solution, the process is faster and its effectivity is higher when using CdS/ZnS nanocomposite, compared to single phase CdS. Very low cytotoxic activity (high viability) of the cancer cell lines (selected as models of living cells) has been evidenced for CdS/ZnS in comparison with CdS alone. This fact is in a close relationship with Cd(II) ions dissolution tested in a physiological solution. The concentration of cadmium dissolved from CdS/ZnS nanocomposites with variable Cd:Zn ratio was 2.5–5.0 μg.mL{sup −1}, whereas the concentration for pure CdS was much higher — 53 μg.ml{sup −1}. The presence of ZnS in the nanocrystalline composite strongly reduced the release of cadmium into the physiological solution, which simulated the environment in the human body. The obtained CdS/ZnS quantum dots can serve as labeling media and co-agents in future anti-cancer drugs, because of their potential in theranostic applications. - Highlights: • CdS/ZnS nanocomposites with crystallite

  4. Synthesis, characterization and optical properties of polymer-based ZnS nanocomposites.

    Science.gov (United States)

    Tiwari, A; Khan, S A; Kher, R S; Dhoble, S J; Chandel, A L S

    2016-03-01

    Nanostructured polymer-semiconductor hybrid materials such as ZnS-poly(vinyl alcohol) (ZnS-PVA), ZnS-starch and ZnS-hydroxypropylmethyl cellulose (Zns-HPMC) are synthesized by a facile aqueous route. The obtained nanocomposites are characterized using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV/vis spectroscopy and photoluminescence (PL). XRD studies confirm the zinc blende phase of the nanocomposites and indicate the high purity of the samples. SEM studies indicate small nanoparticles clinging to the surface of a bigger particle. The Energy Dispersive Analysis by X-rays (EDAX) spectrum reveals that the elemental composition of the nanocomposites consists primarily of Zn:S. FTIR studies indicate that the polymer matrix is closely associated with ZnS nanoparticles. The large number of hydroxyl groups in the polymer matrix facilitates the complexation of metal ions. The absorption spectra of the specimens show a blue shift in the absorption edge. The spectrum reveals an absorption edge at 320, 310 and 325 nm, respectively. PL of nanocomposites shows broad peaks in the violet-blue region (420-450 nm). The emission intensity changes with the nature of capping agent. The PL intensity of ZnS-HPMC nanocomposites is found to be highest among the studied nanocomposites. The results clearly indicate that hydroxyl-functionalized HPMC is much more effective at nucleating and stabilizing colloidal ZnS nanoparticles in aqueous suspensions compared with PVA and starch. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Synthesis and microwave absorption properties of PPy/Co nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Juhua, E-mail: luojuhua@163.com [School of Materials Engineering, Yancheng Institute of Technology, Yancheng 224051 (China); Gao, Duoduo [School of Material Science and Engineering, Changzhou University, Changzhou 213164 (China)

    2014-11-15

    Polypyrrole (PPy)/cobalt (Co) nanocomposites were successfully prepared by an in-situ polymerization of pyrrole in the presence of synthesized Co nanoparticles. Characterization of the product was accomplished by XRD, TEM, FT-IR, VSM, and vector network analyzer techniques. XRD analysis revealed that characteristic diffraction peaks of polypyrrole and Co appeared at the same time in nanocomposites. FT-IR analysis indicated a successful conjugation of Co particles with polypyrrole. TEM confirmed the formation of a core-shell structure with a wide particle size distribution. Magnetization measurements showed that polypyrrole coating decreased the saturation magnetization of Co significantly. With the increase of the matching thickness, the absorption peak varied towards low frequency direction. When the matching thickness was 3.0 mm, the value of the maximum reflection loss (RL) was −20.0 dB at 13.8 GHz with the 7.2 GHz bandwidth. - Highlights: • The influence of PPy on the structure of Co is discussed. • The influence of PPy on the magnetic properties of Co is discussed. • The influence of PPy on the absorption property of Co is discussed. • PPy/Co possessed the excellent absorption property.

  6. GRAPHENE BASED METAL AND METAL OXIDE NANOCOMPOSITES: SYNTHESIS, PROPERTIES AND THEIR APPLICATIONS

    KAUST Repository

    Khan, Mujeeb

    2015-06-11

    Graphene, an atomically thin two-dimensional carbonaceous material, has attracted tremendous attention in the scientific community, due to its exceptional electronic, electrical, and mechanical properties. Indeed, with the recent explosion of methods for a large-scale synthesis of graphene, the number of publications related to graphene and other graphene based materials have increased exponentially. Particularly the easy preparation of graphene like materials, such as, highly reduced graphene oxide (HRG) via reduction of graphite oxide (GO), offers a wide range of possibilities for the preparation of graphene based inorganic nanocomposites by the incorporation of various functional nanomaterials for a variety of applications. In this review, we discuss the current development of graphene based metal and metal oxide nanocomposites, with a detailed account of their synthesis and properties. Specifically, much attention has been given to their wide range of applications in various fields, including, electronics, electrochemical and electrical fields. Overall, by the inclusion of various references, this review covers in detail aspects of the graphene-based inorganic nanocomposites.

  7. Colloidal synthesis of BaF2 nanoparticles and their application as fillers in polymer nanocomposites

    Science.gov (United States)

    Sathyamurthy, Srivatsan; Tuncer, Enis; More, Karren L.; Gu, Baohua; Sauers, Isidor; Paranthaman, M. Parans

    2012-03-01

    Nanoparticles of pure and Eu-doped BaF2 have been prepared through sol-gel colloidal synthesis. In addition, BaF2-filled PMMA polymer nanocomposites were fabricated and dielectric properties were measured. The as-synthesized pure and Eu-doped BaF2 nanoparticles were analyzed by both X-ray diffraction and transmission electron microscopy and consisted of crystalline BaF2 particles with an average diameter of 13.6 nm with a standard deviation of about ±2.4 nm. The photoluminescence properties of the pure and Eu-doped (2%, 4% and 8%) nanoparticles showed characteristic emission of Eu3+ (5D0→7F J ( J=1-4) transitions). We also measured significantly enhanced dielectric breakdown strength of up to 30% for BaF2 nanocomposites over the unfilled PMMA polymer. This study thus offers some promise of sol-gel synthesis of nanocomposite dielectrics with great potential for use as electrical insulation materials in cryogenic high-voltage applications.

  8. Colloidal synthesis of BaF2 nanoparticles and their application as fillers in polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Sathyamurthy, Srivatsan [ORNL; Tuncer, Enis [ORNL; More, Karren Leslie [ORNL; Gu, Baohua [ORNL; Sauers, Isidor [ORNL; Paranthaman, Mariappan Parans [ORNL

    2012-01-01

    Nanoparticles of pure and Eu-doped BaF2 have been prepared through sol-gel colloidal synthesis. In addition, BaF2 filled PMMA polymer nanocomposites were fabricated and dielectric properties were measured. The as-synthesized pure and Eu-doped BaF2 nanoparticles were analyzed by both X-ray diffraction and transmission electron microscopy and consisted of crystalline BaF2 particles with an average diameter of 13.6 nm with a standard deviation of about 2.4 nm. The photoluminescence properties of the pure and Eu-doped (2%, 4% and 8%) nanoparticles showed characteristic emission of Eu3+ (5D0 7FJ (J=1-4) transitions). We also measured significantly enhanced dielectric breakdown strength of up to 30% for BaF2 nanocomposites over the unfilled PMMA polymer. This study thus offers some promise of sol-gel synthesis of nanocomposite dielectrics with great potential for use as electrical insulation materials in cryogenic high voltage applications.

  9. GRAPHENE BASED METAL AND METAL OXIDE NANOCOMPOSITES: SYNTHESIS, PROPERTIES AND THEIR APPLICATIONS

    KAUST Repository

    Khan, Mujeeb; Tahir, Muhammad Nawaz; Adil, Syed F; Khan, Hadayat Ullah; Siddiqui, Rafiq H; Al-Warthan, Abdulrahman Abdullah; Tremel, Wolfgang

    2015-01-01

    Graphene, an atomically thin two-dimensional carbonaceous material, has attracted tremendous attention in the scientific community, due to its exceptional electronic, electrical, and mechanical properties. Indeed, with the recent explosion of methods for a large-scale synthesis of graphene, the number of publications related to graphene and other graphene based materials have increased exponentially. Particularly the easy preparation of graphene like materials, such as, highly reduced graphene oxide (HRG) via reduction of graphite oxide (GO), offers a wide range of possibilities for the preparation of graphene based inorganic nanocomposites by the incorporation of various functional nanomaterials for a variety of applications. In this review, we discuss the current development of graphene based metal and metal oxide nanocomposites, with a detailed account of their synthesis and properties. Specifically, much attention has been given to their wide range of applications in various fields, including, electronics, electrochemical and electrical fields. Overall, by the inclusion of various references, this review covers in detail aspects of the graphene-based inorganic nanocomposites.

  10. The synthesis and characterization of biotin-silver-dendrimer nanocomposites as novel bioselective labels

    Energy Technology Data Exchange (ETDEWEB)

    Maly, J; Lampova, H; Semeradtova, A; Stofik, M [Faculty of Science, University of J E Purkynje, 40096 Usti nad Labem (Czech Republic); Kovacik, L, E-mail: malyjalga@seznam.c [Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague (Czech Republic)

    2009-09-23

    This paper presents a synthesis of a novel nanoparticle label with selective biorecognition properties based on a biotinylated silver-dendrimer nanocomposite (AgDNC). Two types of labels, a biotin-AgDNC (bio-AgDNC) and a biotinylated AgDNC with a poly(ethylene)glycol spacer (bio-PEG-AgDNC), were synthesized from a generation 7 (G7) hydroxyl-terminated ethylenediamine-core-type (2-carbon core) PAMAM dendrimer (DDM) by an N,N'-dicyclohexylcarbodiimide (DDC) biotin coupling and a NaBH{sub 4} silver reduction method. Synthesized conjugates were characterized by several analytical methods, such as UV-vis, FTIR, AFM, TEM, ELISA, HABA assay and SPR. The results show that stable biotinylated nanocomposites can be formed either with internalized silver nanoparticles (AgNPs) in a DMM polymer backbone ('type I') or as externally protected ('type E'), depending on the molar ratio of the silver/DMM conjugate and type of conjugate. Furthermore, the selective biorecognition function of the biotin is not affected by the AgNPs' synthesis step, which allows a potential application of silver nanocomposite conjugates as biospecific labels in various bioanalytical assays, or potentially as fluorescence cell biomarkers. An exploitation of the presented label in the development of electrochemical immunosensors is anticipated.

  11. Electrochemical synthesis, in situ spectroelectrochemistry of conducting indole-titanium dioxide and zinc oxide polymer nanocomposites for rechargeable batteries

    International Nuclear Information System (INIS)

    Parvin, Mohammad Hadi; Pirnia, Mahsa; Arjomandi, Jalal

    2015-01-01

    Highlights: • Two novel hybrid materials-based conducting PIn rechargeable batteries were developed. • The charge-discharging behavior of PIn-nanocomposite batteries were studied. • The characterization of samples has been done by in situ spectroelectrochemical method. • PIn-TiO 2 and ZnO nanocomposites were synthesized electrochemically on Au and ITO. • The PIn-TiO 2 and ZnO nanocomposites resistances were less than PIn. - Abstract: Electrochemical synthesis, in situ spectroelectrochemistry of conducting polyindole (PIn), polyindole-TiO 2 (PIn-TiO 2 ) and polyindole-ZnO (PIn-ZnO) nanocomposites were investigated. The PIn and polymer nanocomposites were tested electrochemically for rechargeable batteries. The films were characterized by means of CVs, in situ UV-visible, FT-IR spectroscopies, in situ resistivity measurements, energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The charge-discharging behavior of a Zn/1 M ZnSO 4 /PIn cell with a capacity of around 90 Ah Kg −1 and on open circuit potential of around 1.45 V was compared with Zn/1 M ZnSO 4 /PIn-nanocomposite. The potential differences of redox couples (ΔE) for nanocomposites films show very good reversibility. A positive shift of potential was observed for polymer nanocomposites during redox scan. A significant variability was observed for in situ conductivity of the PIn and polymer nanocomposites. During in situ UV-visible and FT-IR measurements, intermediate spectroscopic behavior and positive shifts of wavelengths were observed for PIn and polymer nanocomposites. The SEM, TEM and EDX of nanocomposite films show the presence of nano particle in PIn.

  12. Synthesis of malachite@clay nanocomposite for rapid scavenging of cationic and anionic dyes from synthetic wastewater.

    Science.gov (United States)

    Srivastava, Varsha; Sillanpää, Mika

    2017-01-01

    Synthesis of malachite@clay nanocomposite was successfully carried out for the removal of cationic (Methylene Blue, MB) and anionic dyes (Congo Red, CR) from synthetic wastewater. Nanocomposite was characterized by TEM, SEM, FT-IR, EDS analysis and zeta potential. TEM analysis indicated that the particle diameter of nanocomposite was in the range of 14 to 23nm. Various important parameters viz. contact time, concentration of dyes, nanocomposite dosage, temperature and solution pH were optimized to achieve maximum adsorption capacity. In the case of MB, removal decreased from 99.82% to 93.67% while for CR, removal decreased from 88.55% to 75.69% on increasing dye concentration from 100 to 450mg/L. pH study confirmed the higher removal of CR in acidic range while MB removal was higher in alkaline range. Kinetic study revealed the applicability of pseudo-second-order model for the adsorption of both dyes. Negative values of ΔG 0 for both systems suggested the feasibility of dye removal and support for spontaneous adsorption of CR and MB on nanocomposite. Nanocomposite showed 277.77 and 238.09mg/g Langmuir adsorption capacity for MB and CR respectively. Desorption of dyes from the dye loaded nanocomposite was easily carried out with acetone. The results indicate that the prepared malachite@clay nanocomposite is an efficient adsorbent with high adsorption capacity for the aforementioned dyes. Copyright © 2016. Published by Elsevier B.V.

  13. Lanthanides-clay nanocomposites: Synthesis, characterization and optical properties

    International Nuclear Information System (INIS)

    Celedon, Salvador; Quiroz, Carolina; Gonzalez, Guillermo; Sotomayor Torres, Clivia M.; Benavente, Eglantina

    2009-01-01

    Complexes of Europium(III) and Terbium(III) with 2,2-bipyridine and 1,10-phenanthroline were inserted into Na-bentonite by ion exchange reactions at room temperature. The products display interlaminar distances and stoichiometries in agreement with the ion exchange capacity and the interlayer space available in the clay. The optical properties of the intercalates, being qualitatively similar to those of the free complexes, are additionally improved with respect to exchange processes with the medium, especially in a moist environment. The protection again hydrolysis, together with the intensity of the optical transition 5 D 0 - 5 F 2 observed in the nanocomposite, makes these products promising for the development of novel optical materials

  14. Synthesis and Antimicrobial Activity of a Silver-Hydroxyapatite Nanocomposite

    Directory of Open Access Journals (Sweden)

    Marcos Díaz

    2009-01-01

    Full Text Available A silver-hydroxyapatite nanocomposite has been obtained by a colloidal chemical route and subsequent reduction process in H2/Ar atmosphere at 350∘C. This material has been characterized by TEM, XRD, and UV-Visible spectroscopy, showing the silver nanoparticles (∼65 nm supported onto the HA particles (∼130 nm surface without a high degree of agglomeration. The bactericidal effect against common Gram-positive and Gram-negative bacteria has been also investigated. The results indicated a high antimicrobial activity for Staphylococcus aureus, Pneumococcus and Escherichia coli, so this material can be a promising antimicrobial biomaterial for implant and reconstructive surgery applications.

  15. Green Synthesis and Characterization of Carbon Nanotubes/Polyaniline Nanocomposites

    Directory of Open Access Journals (Sweden)

    Van Hoa Nguyen

    2015-01-01

    Full Text Available Carbon nanotubes/polyaniline (CNT/PANI nanocomposites were synthesized by the interfacial polymerization of aniline in the presence of CNTs using two green solvents, water and an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4], as the two phases. The formation and incorporation of PANI on the surface of the CNTs were confirmed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy. The analyses showed that the surface of the CNTs was coated with different morphologies of thin PANI layers depending on whether a HCl or HNO3 solution was used. The thermal stability of the composites was much better than that of the bare CNTs and pure PANI. The as-prepared composites were also used to modify the nickel foam electrodes for characterization of the electrochemical properties.

  16. Solvothermal synthesis of V2O5/graphene nanocomposites for high performance lithium ion batteries

    International Nuclear Information System (INIS)

    Chen, Da; Yi, Ran; Chen, Shuru; Xu, Terrence; Gordin, Mikhail L.; Lv, Dongping; Wang, Donghai

    2014-01-01

    Highlights: • A homogeneous V 2 O 5 /graphene nanocomposite is successfully synthesized. • V 2 O 5 nanoparticles are highly encapsulated in the 2D graphene matrix. • V 2 O 5 /graphene nanocomposite shows much better performance than bare V 2 O 5 . - Abstract: In this work, V 2 O 5 /graphene nanocomposites have been synthesized by a facile solvothermal approach. The V 2 O 5 nanoparticles, around 20–40 nm in size, were encapsulated in the 2D graphene matrix. The reversible Li-cycling properties of V 2 O 5 /graphene have been evaluated by galvanostatic discharge–charge cycling, cyclic voltammetry, and impedance spectroscopy. Compared with the bare V 2 O 5 nanoparticles, the V 2 O 5 /graphene nanocomposites exhibited enhanced electrochemical performance with higher reversible capacity and improved cycling stability and rate capability. The graphene nanosheets act not only as an electronically conductive matrix to improve the electronic and ionic conductivity of the composite electrode, but also as a flexible buffer matrix to maintain the structural integrity of the composite electrodes by preventing particle agglomeration, thus leading to the improvement of the electrochemical performance of V 2 O 5

  17. In Situ Synthesis of Reduced Graphene Oxide and Gold Nanocomposites for Nanoelectronics and Biosensing

    Directory of Open Access Journals (Sweden)

    Chen Peng

    2011-01-01

    Full Text Available Abstract In this study, an in situ chemical synthesis approach has been developed to prepare graphene–Au nanocomposites from chemically reduced graphene oxide (rGO in aqueous media. UV–Vis absorption, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy were used to demonstrate the successful attachment of Au nanoparticles to graphene sheets. Configured as field-effect transistors (FETs, the as-synthesized single-layered rGO-Au nanocomposites exhibit higher hole mobility and conductance when compared to the rGO sheets, promising its applications in nanoelectronics. Furthermore, we demonstrate that the rGO-Au FETs are able to label-freely detect DNA hybridization with high sensitivity, indicating its potentials in nanoelectronic biosensing.

  18. Synthesis and characterization of nanocomposite powders of calcium phosphate/titanium oxide for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Delima, S.A.; Camargo, N.H.A.; Souza, J.C.P.; Gemelli, E., E-mail: sarahamindelima@hotmail.com, E-mail: dem2nhac@joinville.udesc.br, E-mail: souzajulio@joinville.udesc.br, E-mail: gemelli@joinville.udesc.br [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Centro de Ciencias Tecnologicas

    2009-07-01

    The nanostructured bioceramics of calcium phosphate are current themes of research and they are becoming important as bone matrix in regeneration of tissues in orthopedic and dental applications. Nanocomposite powders of calcium phosphate, reinforced with nanometric particles of titanium oxide, silica oxide and alumina oxid ealpha, are being widely studied because they offer new microstructures, nanostructures and interconnected microporosity with high superficial area of micropores that contribute to osteointegration and osteoinduction processes. This study is about the synthesis of nanocomposites powders of calcium phosphate reinforced with 1%, 2%, 3% and 5% in volume of titanium oxide and its characterization through the techniques of X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis (DTA), Thermogravimetry (TG) and Dilatometry. (author)

  19. Recent Advances in the Synthesis and Biomedical Applications of Nanocomposite Hydrogels

    Directory of Open Access Journals (Sweden)

    Umile Gianfranco Spizzirri

    2015-10-01

    Full Text Available Hydrogels sensitive to electric current are usually made of polyelectrolytes and undergo erosion, swelling, de-swelling or bending in the presence of an applied electric field. The electrical conductivity of many polymeric materials used for the fabrication of biomedical devices is not high enough to achieve an effective modulation of the functional properties, and thus, the incorporation of conducting materials (e.g., carbon nanotubes and nanographene oxide was proposed as a valuable approach to overcome this limitation. By coupling the biological and chemical features of both natural and synthetic polymers with the favourable properties of carbon nanostructures (e.g., cellular uptake, electromagnetic and magnetic behaviour, it is possible to produce highly versatile and effective nanocomposite materials. In the present review, the recent advances in the synthesis and biomedical applications of electro-responsive nanocomposite hydrogels are discussed.

  20. Synthesis and characterization of nanocomposite powders of calcium phosphate/titanium oxide for biomedical applications

    International Nuclear Information System (INIS)

    Delima, S.A.; Camargo, N.H.A.; Souza, J.C.P.; Gemelli, E.

    2009-01-01

    The nanostructured bioceramics of calcium phosphate are current themes of research and they are becoming important as bone matrix in regeneration of tissues in orthopedic and dental applications. Nanocomposite powders of calcium phosphate, reinforced with nanometric particles of titanium oxide, silica oxide and alumina oxid ealpha, are being widely studied because they offer new microstructures, nanostructures and interconnected microporosity with high superficial area of micropores that contribute to osteointegration and osteoinduction processes. This study is about the synthesis of nanocomposites powders of calcium phosphate reinforced with 1%, 2%, 3% and 5% in volume of titanium oxide and its characterization through the techniques of X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis (DTA), Thermogravimetry (TG) and Dilatometry. (author)

  1. In situ chemical synthesis of ruthenium oxide/reduced graphene oxide nanocomposites for electrochemical capacitor applications.

    Science.gov (United States)

    Kim, Ji-Young; Kim, Kwang-Heon; Yoon, Seung-Beom; Kim, Hyun-Kyung; Park, Sang-Hoon; Kim, Kwang-Bum

    2013-08-07

    An in situ chemical synthesis approach has been developed to prepare ruthenium oxide/reduced graphene oxide (RGO) nanocomposites. It is found that as the C/O ratio increases, the number density of RuO2 nanoparticles decreases, because the chemical interaction between the Ru ions and the oxygen-containing functional groups provides anchoring sites where the nucleation of particles takes place. For electrochemical capacitor applications, the microwave-hydrothermal process was carried out to improve the conductivity of RGO in RuO2/RGO nanocomposites. The significant improvement in capacitance and high rate capability might result from the RuO2 nanoparticles used as spacers that make the interior layers of the reduced graphene oxide electrode available for electrolyte access.

  2. Sol–gel synthesis and luminescence of undoped and Mn-doped zinc orthosilicate phosphor nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    El Ghoul, J., E-mail: ghoultn@yahoo.fr [Laboratoire de Physique des Matériaux et des Nanomatériaux Appliquée à l’Environnement, Faculté des Sciences de Gabès, Cité Erriadh Manara Zrig, 6072 Gabès (Tunisia); El Mir, L. [Laboratoire de Physique des Matériaux et des Nanomatériaux Appliquée à l’Environnement, Faculté des Sciences de Gabès, Cité Erriadh Manara Zrig, 6072 Gabès (Tunisia); Al Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Sciences, Departement of Physics, Riyadh 11623 (Saudi Arabia)

    2014-04-15

    Zn{sub 2}SiO{sub 4} and Zn{sub 2}SiO{sub 4}:Mn particles embedded in SiO{sub 2} host matrix prepared by sol gel method under supercritical conditions of ethyl alcohol in two steps. Were prepared by a simple solid-phase reaction under natural atmosphere at 1200 °C after the incorporation of ZnO and ZnO:Mn nanoparticles, respectively, in silica monolith. In the case of SiO{sub 2}/Zn{sub 2}SiO{sub 4} nanocomposite, the powder with an average particle size of 80 nm shows a strong luminescence band centred at around 760 nm in the visible range. In addition, the PL spectrum for the SiO{sub 2}/Zn{sub 2}SiO{sub 4}:Mn nanocomposite showed that a dominant peak at 525 nm appeared, which originated from the {sup 4}T{sub 1}–{sup 6}A{sub 1} transitions of Mn{sup 2+} ions. The luminescence properties of nanocomposites were characterized by emission and excitation spectra as well their dependencies of upon temperature and power excitation density. -- Highlights: • The Synthesis of Zn{sub 2}SiO{sub 4} nanocomposites. • Structural and optical characterizations of Zn{sub 2}SiO{sub 4} and Zn{sub 2}SiO{sub 4}:Mn nanocomposites. • The willemite α-Zn{sub 2}SiO{sub 4} structure was formed to the heat treatment temperature 1200 °C. • The powder exhibits a nanometric size. • Strong bands of luminescence have appeared.

  3. Hydrothermal synthesis of carbonyl iron-carbon nanocomposite: Characterization and electromagnetic performance

    Directory of Open Access Journals (Sweden)

    Hakimeh Pourabdollahi

    Full Text Available In this research, the electromagnetic absorption properties of the carbonyl iron-carbon (CI/C nanocomposite prepared via hydrothermal reaction using glucose as carbon precursor was studied in the range of 8.2–12.4 GHz. In hydrothermal reaction, glucose solution containing CI particles, placed in autoclave for 4 h under 453 K. Using surface coating technology is a method that prevents Cl oxidation and improves CI electromagnetic absorption. The structure, morphology and magnetic performances of the prepared nanocomposites were characterized by X-ray diffraction (XRD, energy dispersive spectrometry (EDS, transmission electron microscopy (TEM and vibrating sample magnetometer (VSM. The electromagnetic properties including complex permittivity (εr, the permeability (µr, dielectric loss, magnetic loss, reflection loss, and attenuation constant were investigated using a vector network analyzer. For The CI/C nanocomposite, the bandwidth of −10 dB and −20 dB were obtained in the frequency range of 9.8–12.4 and 11.0–11.8 GHz, respectively. As well as, the reflection loss was −46.69 dB at the matching frequency of 11.5 GHz, when the matching thickness was 1.3 mm. While for CI particles the reflection loss for 4.4 mm thickness was −16.86 dB at the matching frequency of 12.3 GHz. The results indicate that the existence layer of carbon on carbonyl iron enhance the electromagnetic absorbing properties. Therefore, this nanocomposite can be suitable for in the radar absorbing coatings. Keywords: Hydrothermal synthesis, Carbonyl iron-carbon nanocomposite, Microwave absorption, Reflection loss

  4. Quercetin-mediated synthesis of graphene oxide–silver nanoparticle nanocomposites: a suitable alternative nanotherapy for neuroblastoma

    Directory of Open Access Journals (Sweden)

    Yuan YG

    2017-08-01

    mitochondrial membrane potential, reduced numbers of mitochondria, enhanced level of reactive oxygen species generation, increased expression of pro-apoptotic genes, and decreased expression of anti-apoptotic genes. GO-AgNPs induced caspase-9/3-dependent apoptosis via DNA fragmentation. Finally, GO-AgNPs induced accumulation of autophagosomes and autophagic vacuoles.Conclusion: In this study, we developed an environmentally friendly, facile, dependable, and simple method for the synthesis of GO-AgNPs nanocomposites using quercetin. The synthesized GO-AgNPs exhibited enhanced cytotoxicity compared with that of GO at very low concentrations. This study not only elucidates the potential cytotoxicity against neuroblastoma cancer cells, but also reveals the molecular mechanism of toxicity. Keywords: neuroblastoma, cell viability, cytotoxicity, graphene oxide–silver nanoparticles nanocomposite, apoptosis, autophagy

  5. A simple biogenic route to rapid synthesis of Au-TiO{sub 2} nanocomposites by electrochemically active biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Kalathil, Shafeer; Khan, Mohammad Mansoob [Yeungnam University, School of Chemical Engineering (Korea, Republic of); Banerjee, Arghya Narayan [Yeungnam University, School of Mechanical Engineering (Korea, Republic of); Lee, Jintae; Cho, Moo Hwan, E-mail: mhcho@ynu.ac.kr [Yeungnam University, School of Chemical Engineering (Korea, Republic of)

    2012-08-15

    Deposition of gold on titanium dioxide (TiO{sub 2}) nanoparticles is highly beneficial for maximizing the efficiency of many photocatalytic reactions. In this study, we have reported for the first time the use of an electrochemically active biofilm (EAB) for the synthesis of Au-TiO{sub 2} nanocomposite with sodium acetate as the electron donor. The EAB acts as an electron generator for the reduction of gold ions on the surface of TiO{sub 2} nanoparticles. It was observed that the TiO{sub 2} plays not only as a support for the gold nanoparticles but also as a storage of electrons produced by the EAB within the particles. These stored electrons dramatically increase the reduction of gold ions and hence we have observed the formation of the Au-TiO{sub 2} nanocomposites within 90 min. A mechanism of the nanocomposite formation is also proposed. The as-synthesized nanocomposites were characterized by UV-Vis absorption spectroscopy to monitor the proper formation of the nanocomposites. X-ray diffraction and transmission electron microscopic analyses were performed to determine the structural and microstructural properties of the nanocomposites. High-resolution transmission electron micrographs depict the proper formation of the Au-TiO{sub 2} nanocomposites with gold nanoparticle size varying from 5 to 10 nm with an increase in the gold precursor concentration. Zeta potential measurements were used to investigate surface charges of the as-synthesized nanocomposites. This novel biogenic route represents a unique pathway for the low cost, eco-friendly, rapid, and controlled synthesis of nanostructured Au-TiO{sub 2} hybrid systems which will truly revolutionize the synthetic fields of nanocomposites.

  6. Synthesis of zinc sulfide nanoparticles and their incorporation into poly(hydroxybutyrate) matrix in the formation of a novel nanocomposite

    Science.gov (United States)

    Riaz, Shahina; Raza, Zulfiqar Ali; Majeed, Muhammad Irfan; Jan, Tariq

    2018-05-01

    In the present study, zinc sulfide (ZnS) nanoparticles (NPs) were successfully synthesized through a modified chemical precipitation protocol and then mediated into poly(hydroxybutyrate) (PHB) matrix to get ZnS/PHB nanocomposite. Mean diameter and zeta potential of ZnS NPs, as determined using dynamic light scattering technique (DLS), were observed to be 53 nm and ‑89 mV, respectively. The structural investigations performed using x-ray diffraction (XRD) technique depicted the phase purity of ZnS NPs exhibiting cubic crystal structure. Fourier transform infrared (FTIR) spectroscopic analysis was conducted to identify the presence or absence of bonding vibrational modes on the surface of synthesized single phase ZnS NPs. The FTIR analysis confirmed the metal to sulphur bond formation by showing the characteristic band at 1123 cm‑1. The UV–vis absorption spectra of ZnS NPs confirmed the synthesis of particles in nanoscale regime showing a λ max of 302 nm. These NPs were then successfully incorporated into PHB matrix to synthesize ZnS/PHB nanocomposite. The synthesis of nanocomposite was confirmed by EDX analysis. The chemical bonding and structural properties of ZnS/PHB nanocomposite were determined by FTIR and XRD analysis, respectively. The FTIR analysis confirmed the synthesis of ZnS/PHB nanocomposite. Moreover, XRD analysis showed that structure of nanocomposite was completely controlled by ZnS NPs as pure PHB exhibited orthorhombic crystal structure while the nanocomposite demonstrated cubic crystal structure of ZnS. Thermal properties of nanocomposite were studied through thermogravimetric analysis revealing that the incorporation of ZnS NPs into PHB matrix lead to enhance heat resistance properties of PHB.

  7. All-acrylic superelastomers: facile synthesis and exceptional mechanical behavior

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei; Goodwin, Andrew; Wang, Yangyang; Yin, Panchao; Wang, Weiyu; Zhu, Jiahua; Wu, Ting; Lu, Xinyi; Hu, Bin; Hong, Kunlun; Kang, Nam-Goo; Mays, Jimmy (Tennessee-K); (ORNL)

    2018-01-01

    All-acrylic multigraft copolymers made by a facile synthesis procedure exhibit elongation at break >1700% and strain recovery behavior far exceeding those of commercial acrylic and styrenic triblock copolymers.

  8. Facile template-free hydrothermal synthesis and microstrain ...

    Indian Academy of Sciences (India)

    Administrator

    2009), solar cells (Yuan et al 2011), transparent elec- trodes (Kim et al ... increasing the peak width, intensity and shifting the 2θ peak position. ... Facile template-free hydrothermal synthesis and microstrain measurement of ZnO nanorods. 399.

  9. Synthesis of MoS2-reduced graphene oxide/Fe3O4 nanocomposite for enhanced electromagnetic interference shielding effectiveness

    Science.gov (United States)

    Prasad, Jagdees; Singh, Ashwani Kumar; Shah, Jyoti; Kotnala, R. K.; Singh, Kedar

    2018-05-01

    This article presents a facile two step hydrothermal process for the synthesis of MoS2-reduced graphene oxide/Fe3O4 (MoS2-rGO/Fe3O4) nanocomposite and its application as an excellent electromagnetic interference shielding material. Characterization tools like; scanning electron microscope, transmission electron microscope, x-ray diffraction, and Raman spectroscopy were used to confirm the formation of nanocomposite and found that spherical Fe3O4 nanoparticles are well dispersed over MoS2-rGO composite with average particle size ∼25–30 nm was confirmed by TEM. Structural characterization done by XRD was found inconsistent with the known lattice parameter of MoS2 nanosheet, reduced graphene oxide and Fe3O4 nanoparticles. Electromagnetic shielding effectiveness of MoS2-rGO/Fe3O4 nanocomposite was evaluated and found to be an excellent EMI shielding material in X-band range (8.0–12.0 GHz). MoS2-rGO composite shows poor shielding capacity (SET ∼ 3.81 dB) in entire range as compared to MoS2-rGO/Fe3O4 nanocomposite (SET ∼ 8.27 dB). It is due to interfacial polarization in the presence of EM field. The result indicates that MoS2-rGO/Fe3O4 nanocomposite provide a new stage for the next generation in high-performance EM wave absorption and EMI shielding effectiveness.

  10. Facile Route to Transparent, Strong, and Thermally Stable Nanocellulose/Polymer Nanocomposites from an Aqueous Pickering Emulsion.

    Science.gov (United States)

    Fujisawa, Shuji; Togawa, Eiji; Kuroda, Katsushi

    2017-01-09

    Cellulose nanofibril (CNF) is a promising nanofiller for polymer nanocomposite materials, and a critical challenge in designing these materials is organization of the nanostructure using a facile process. Here, we report a facile aqueous preparation process for nanostructured polystyrene (PS)/CNF composites via the formation of a CNF-stabilized Pickering emulsion. PS nanoparticles, with a narrow size distribution, were synthesized by free radical polymerization in water using CNF as a stabilizer. The nanoparticles were easily collected by filtration, and the resulting material had a composite structure of PS nanoparticles embedded in a CNF framework. The PS/CNF nanocomposite showed high optical transparency, strength, and thermal dimensional stability. Thus, this technique provides a simple and environmentally friendly method for the preparation of novel CNF/polymer nanocomposite materials.

  11. Green synthesis, characterization, and anticancer activity of hyaluronan/zinc oxide nanocomposites

    Directory of Open Access Journals (Sweden)

    Namvar F

    2016-07-01

    were treated with HA/ZnO nanocomposite. At 72 hours of treatment, the half maximal inhibitory concentration (IC50 value via the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay was 10.8±0.3 µg/mL, 15.4±1.2 µg/mL, 12.1±0.9 µg/mL, and 6.25±0.5 µg/mL for the PANC-1, CaOV-3, COLO-205, and HL-60 cells, respectively, showing that the composite is most toxic to the HL-60 cells. On the other hand, HA/ZnO nanocomposite treatment for 72 hours did not cause toxicity to the normal human lung fibroblast (MRC-5 cell line. Using fluorescent dyes and flow cytometry analysis, HA/ZnO nanocomposite caused G2/M cell cycle arrest and stimulated apoptosis-related increase in caspase-3 and -7 activities of the HL-60 cells. Thus, the study shows that the HA/ZnO nanocomposite produced through green synthesis has great potential to be developed into an efficacious therapeutic agent for cancers. Keywords: green synthesis, hyaluronan, zinc oxide nanocomposite, anticancer activity

  12. Synthesis and characterization of graphene/cellulose nanocomposite

    Science.gov (United States)

    Kafy, Abdullahil; Yadav, Mithilesh; Kumar, Kishor; Kumar, Kishore; Mun, Seongcheol; Gao, Xiaoyuan; Kim, Jaehwan

    2014-04-01

    Cellulose is one of attractive natural polysaccharides in nature due to its good chemical stability, mechanical strength, biocompatibility, hydrophilic, and biodegradation properties [1-2]. The main disadvantages of biopolymer films like cellulose are their poor mechanical properties. Modification of polymers with inorganic materials is a new way to improve polymer properties such as mechanical strength [3-4]. Presently, the use of graphene/graphene oxide (GO) in materials research has attracted tremendous attention in the past 40 years in various fields including biomedicine, information technology and nanotechnology[5-7]. Graphene, a single sheet of graphite, has an ideal 2D structure with a monolayer of carbon atoms packed into a honeycomb crystal plane. Using both experimental and theoretical scientific research, researchers including Geim, Rao and Stankovich [8-10] have described the attractiveness of graphene in the materials research field. Due to its sp2 hybrid carbon network as well as extraordinary mechanical, electronic, and thermal properties, graphene has opened new pathways for developing a wide range of novel functional materials. Perfect graphene does not exist naturally, but bulk and solution processable functionalized graphene materials including graphene oxide (GO) can now be prepared [11-13].The large surface area of GO has a number of functional groups, such as -OH, -COOH, -O- , and C=O, which make GO hydrophilic and readily dispersible in water as well as some organic solvents[14] , thereby providing a convenient access to fabrication of graphene-based materials by solution casting. According to several reports [15-17], GO can be dispersed throughout a selected polymer matrix to make GO-based nanocomposites with excellent mechanical and thermal properties. Since GO is prepared from low-cost graphite, it has an outstanding price advantage over CNTs, which has encouraged studies of GO/synthetic polymer composites [18-20]. In some reported papers

  13. Synthesis of dextran/Se nanocomposites for nanomedicine application

    International Nuclear Information System (INIS)

    Shen Yuhua; Wang Xiufang; Xie Anjian; Huang Lachun; Zhu Jinmiao; Chen Long

    2008-01-01

    In this study, spherical Se nanoparticles were prepared by the reduction of aqueous selenious acid with ice bath through a simple, conventional, and one-step method without the aid of any surfactant, or template. The nanoparticles were characterized by transmission electron microscopy (TEM), photon correlation spectroscopy (PCS), X-ray powder diffraction (XRD), Ultraviolet-visible spectroscopy (UV-vis), Zeta potential, respectively. The results show the Se nanoparticles have good particle dispersion with the average diameters of 36 nm and are amorphous (α-Se). Tablets A and B containing dextran and Se nanoparticles were synthesized with different preparation methods. Se nanoparticles studded equably in the interior and the surface of the tablets, and there are strong interactions between Se and dextran. The release of Se from tablets is investigated in the simulated gastric and intestinal conditions. It is found that the pH environment and different synthetical methods have significant influence on the release rate of Se. The release mechanism of Se nanoparticles is also discussed. The nanocomposites can be applied in controlled releasing of Se nanomedicine

  14. In situ synthesis of nanocomposite membranes: comprehensive improvement strategy for direct methanol fuel cells.

    Science.gov (United States)

    Rao, Siyuan; Xiu, Ruijie; Si, Jiangju; Lu, Shanfu; Yang, Meng; Xiang, Yan

    2014-03-01

    In situ synthesis is a powerful approach to control nanoparticle formation and consequently confers extraordinary properties upon composite membranes relative to conventional doping methods. Herein, uniform nanoparticles of cesium hydrogen salts of phosphotungstic acid (CsPW) are controllably synthesized in situ in Nafion to form CsPW–Nafion nanocomposite membranes with both improved proton conductivity and methanol-crossover suppression. A 101.3% increase of maximum power density has been achieved relative to pristine Nafion in a direct methanol fuel cell (DMFC), indicating a potential pathway for large-scale fabrication of DMFC alternative membranes.

  15. Synthesis of multi-walled carbon nanotubes and their application in resin based nanocomposites

    International Nuclear Information System (INIS)

    Ahmad, Shahid Nisar; Hakeem, Saira; Alvi, Rashid Ahmed; Farooq, Khawar; Farooq, Naveed; Yasmin, Farida; Saeed, Sadaf

    2013-01-01

    Multi-walled carbon nanotubes (MWCNTs) were synthesized by catalytic decomposition of hydrocarbon gas using chemical vapor deposition method. Synthesis was done at different growth temperatures and catalyst ratios. These MWCNTs were dispersed in epoxy resin (E-51) and their effect on mechanical strength of epoxy nanocomposites was studied. Increase in the mechanical strength of epoxy was observed with the addition of CNTs. The surface characterization was done by using optical microscope and scanning electron microscope (SEM). Mechanical properties were determined by the general tensile strength testing method.

  16. A facile approach to fabrication of novel CeO2–TiO2 core–shell nanocomposite leads to excellent UV-shielding ability and lower catalytic activity

    International Nuclear Information System (INIS)

    Bahadur, Newaz Mohammed; Kurayama, Fumio; Furusawa, Takeshi; Sato, Masahide; Siddiquey, Iqbal Ahmed; Hossain, Md. Mufazzal; Suzuki, Noboru

    2013-01-01

    This study reports the development of a fast and facile route for the synthesis of novel CeO 2 –TiO 2 core–shell nanocomposite particles using microwave (MW) irradiation of the mixture of commercial CeO 2 , titanium-tetra-n-butoxide (TBOT) and aqueous ammonia. Solutions of TBOT in ethanol and ammonia were mixed with dispersed CeO 2 nanoparticles in ethanol, and the mixture was rapidly MW irradiated at 70 °C for 2 min. The resulting nanocomposite particles were characterized in terms of phase, shell thickness, composition, surface charge, morphology, and chemical state of the elements by XRD, TEM, XPS, SEM, Zeta potential analyzer, XRF, and FT-IR. Conventional methods of the synthesis of CeO 2 –TiO 2 nanocomposite require a long time, and TiO 2 is rarely found as a coated material. In contrast, the MW method was able to synthesize CeO 2 –TiO 2 core–shell nanocompsite particles within a very short time. CeO 2 –TiO 2 nanocomposite particles were fairly unaggregated with an average titania layer thickness of 2–5 nm. The obtained nanocomposites retained the crystalline cubic phase of CeO 2 , and the phase of coated TiO 2 was amorphous. The catalytic activities of uncoated and TiO 2 -coated CeO 2 nanoparticles for the oxidation of organic compounds were evaluated by the degradation study of methylene blue in air atmosphere at 403 K. The enhanced UV-shielding ability and visible transparency of the nanocomposite obtained by UV visible spectroscopic measurements suggested that the core–shell material has novel characteristics for using as a sunscreen material.

  17. A facile approach to fabrication of novel CeO{sub 2}-TiO{sub 2} core-shell nanocomposite leads to excellent UV-shielding ability and lower catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Bahadur, Newaz Mohammed, E-mail: nmbahadur@yahoo.com [Utsunomiya University, Laboratory of Powder Technology, Graduate School of Engineering, Venture Business Laboratry (Japan); Kurayama, Fumio [Utsunomiya University, Center for Optical Research and Education (Japan); Furusawa, Takeshi; Sato, Masahide [Utsunomiya University, Department of Advanced Interdisciplinary Sciences (Japan); Siddiquey, Iqbal Ahmed [Utsunomiya University, Laboratory of Powder Technology, Graduate School of Engineering, Venture Business Laboratry (Japan); Hossain, Md. Mufazzal [University of Dhaka, Department of Chemistry (Bangladesh); Suzuki, Noboru [Utsunomiya University, Laboratory of Powder Technology, Graduate School of Engineering, Venture Business Laboratry (Japan)

    2013-01-15

    This study reports the development of a fast and facile route for the synthesis of novel CeO{sub 2}-TiO{sub 2} core-shell nanocomposite particles using microwave (MW) irradiation of the mixture of commercial CeO{sub 2}, titanium-tetra-n-butoxide (TBOT) and aqueous ammonia. Solutions of TBOT in ethanol and ammonia were mixed with dispersed CeO{sub 2} nanoparticles in ethanol, and the mixture was rapidly MW irradiated at 70 Degree-Sign C for 2 min. The resulting nanocomposite particles were characterized in terms of phase, shell thickness, composition, surface charge, morphology, and chemical state of the elements by XRD, TEM, XPS, SEM, Zeta potential analyzer, XRF, and FT-IR. Conventional methods of the synthesis of CeO{sub 2}-TiO{sub 2} nanocomposite require a long time, and TiO{sub 2} is rarely found as a coated material. In contrast, the MW method was able to synthesize CeO{sub 2}-TiO{sub 2} core-shell nanocompsite particles within a very short time. CeO{sub 2}-TiO{sub 2} nanocomposite particles were fairly unaggregated with an average titania layer thickness of 2-5 nm. The obtained nanocomposites retained the crystalline cubic phase of CeO{sub 2}, and the phase of coated TiO{sub 2} was amorphous. The catalytic activities of uncoated and TiO{sub 2}-coated CeO{sub 2} nanoparticles for the oxidation of organic compounds were evaluated by the degradation study of methylene blue in air atmosphere at 403 K. The enhanced UV-shielding ability and visible transparency of the nanocomposite obtained by UV visible spectroscopic measurements suggested that the core-shell material has novel characteristics for using as a sunscreen material.

  18. Novel synthesis of tin oxide/graphene aerogel nanocomposites as anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Wu, Zheyu; Li, Xifei; Tai, Limin; Song, Haoze; Zhang, Yiyan; Yan, Bo; Fan, Linlin; Shan, Hui; Li, Dejun

    2015-01-01

    A novel method of mechanical exfoliation followed by hydrothermal approach was proposed to synthesize the tin oxide/graphene aerogels (SnO 2 /GAs) nanocomposites. Homogeneous distribution of SnO 2 nanocrystals on GAs was confirmed by SEM, XRD and TEM characterization. It was found that optimized exfoliation of the SnS 2 is the key factor to obtain high electrochemical lithiation/delithiation performance of the anodes. The as-prepared SnO 2 /GA nanocomposites exhibited high reversible capacity (up to 1086.7 mAh g −1 after 100 cycles) and excellent cycling stability. The improved rate capability was also obtained, for instance, the reversible capacity at a current density of 800 mA g −1 is over 447.9 mAh g −1 , and then recovered to as high as 784.4 mAh g −1 at a current density of 100 mA g −1 . - Highlights: • A novel approach was employed to synthesize the SnO 2 /GA nanocomposites. • The designed SnO 2 /GAs exhibited high reversible capacity and excellent cycling stability. • The volume change challenge of SnO 2 was markedly alleviated by the GA matrix. • The novel synthesis method can be extended for other materials in lithium ion batteries

  19. Synthesis and characterization of PTP/[Fe(CN){sub 3}(dien)]·H{sub 2}O nanocomposite; study of electrical, thermal and photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Moosvi, Syed Kazim; Majid, Kowsar, E-mail: kowsarmajid@rediffmail.com; Ara, Tabassum

    2016-10-20

    Highlights: • Synthesis of PTP nanocomposite with photoadduct via in-situ chemical polymerisation. • Photoadduct and its nanocomposite are characterized by UV–Vis, FTIR, XRD, and SEM characterisation techniques. • Enhanced thermal stability of nanocomposite as compared to pure PTP. • Nanocomposite exhibit non-linear I–V behaviour. • Improved electrical properties and photocatalytic activity of nanocomposite as compared to pure PTP. - Abstract: Polythiophene/[Fe(CN){sub 3}(dien)]·H{sub 2}O nanocomposite was synthesised by oxidative chemical polymerisation method. Photoadduct was synthesised by irradiating an equimolar mixture of potassium ferricyanide and diethylenetriamine which was then reduced to nanosize by high energy ball mill. The reduction of photoadduct to nanosize was confirmed from XRD. Nanocomposite of PTP with photoadduct was then prepared by oxidative chemical polymerisation using FeCl{sub 3} as oxidant. The successful synthesis of nanocomposite was confirmed from FTIR, XRD and SEM. TGA revealed higher thermal stability of nanocomposite as compared to pure PTP. I–V characteristics plotted on a log–log scale showed two distinct power law regions in case of nanocomposite. At lower voltages, the transport mechanism follows Ohm’s law. At higher voltages, the mechanism is consistent with space charge-limited emission. Furthermore, nanocomposite shows enhanced conductivity as compared to pure PTP. From dielectric studies, an appreciable high value of dielectric constant (4.4 × 10{sup 6} at 100 Hz) and ac conductivity (2.1 × 10{sup 9} S/m at 300 kHz) of nanocomposite was obtained. This indicates the possible application of this nanocomposite in charge storage devices. The photocatalytic activity of the materials was studied against the methyl orange (MO) dye under UV–Vis light and 76% degradation of MO dye was achieved in presence of nanocomposite in just 2 h, hence indicating its better photocatalytic efficiency. Results thus

  20. Synthesis and characterization of PTP/[Fe(CN)_3(dien)]·H_2O nanocomposite; study of electrical, thermal and photocatalytic properties

    International Nuclear Information System (INIS)

    Moosvi, Syed Kazim; Majid, Kowsar; Ara, Tabassum

    2016-01-01

    Highlights: • Synthesis of PTP nanocomposite with photoadduct via in-situ chemical polymerisation. • Photoadduct and its nanocomposite are characterized by UV–Vis, FTIR, XRD, and SEM characterisation techniques. • Enhanced thermal stability of nanocomposite as compared to pure PTP. • Nanocomposite exhibit non-linear I–V behaviour. • Improved electrical properties and photocatalytic activity of nanocomposite as compared to pure PTP. - Abstract: Polythiophene/[Fe(CN)_3(dien)]·H_2O nanocomposite was synthesised by oxidative chemical polymerisation method. Photoadduct was synthesised by irradiating an equimolar mixture of potassium ferricyanide and diethylenetriamine which was then reduced to nanosize by high energy ball mill. The reduction of photoadduct to nanosize was confirmed from XRD. Nanocomposite of PTP with photoadduct was then prepared by oxidative chemical polymerisation using FeCl_3 as oxidant. The successful synthesis of nanocomposite was confirmed from FTIR, XRD and SEM. TGA revealed higher thermal stability of nanocomposite as compared to pure PTP. I–V characteristics plotted on a log–log scale showed two distinct power law regions in case of nanocomposite. At lower voltages, the transport mechanism follows Ohm’s law. At higher voltages, the mechanism is consistent with space charge-limited emission. Furthermore, nanocomposite shows enhanced conductivity as compared to pure PTP. From dielectric studies, an appreciable high value of dielectric constant (4.4 × 10"6 at 100 Hz) and ac conductivity (2.1 × 10"9 S/m at 300 kHz) of nanocomposite was obtained. This indicates the possible application of this nanocomposite in charge storage devices. The photocatalytic activity of the materials was studied against the methyl orange (MO) dye under UV–Vis light and 76% degradation of MO dye was achieved in presence of nanocomposite in just 2 h, hence indicating its better photocatalytic efficiency. Results thus obtained indicate the

  1. Polymer Nanocomposites

    Indian Academy of Sciences (India)

    methods for the synthesis of polymer nanocomposites. In this article we .... ers, raw materials recovery, drug delivery and anticorrosion .... region giving rise to dose-packed absorption bands called an IR ... using quaternary ammonium salts.

  2. Facile synthesis of porous Pt-Pd nanospheres supported on reduced graphene oxide nanosheets for enhanced methanol electrooxidation

    Science.gov (United States)

    Li, Shan-Shan; Lv, Jing-Jing; Hu, Yuan-Yuan; Zheng, Jie-Ning; Chen, Jian-Rong; Wang, Ai-Jun; Feng, Jiu-Ju

    2014-02-01

    In this study, a simple, facile, and effective wet-chemical strategy was developed in the synthesis of uniform porous Pt-Pd nanospheres (Pt-Pd NSs) supported on reduced graphene oxide nanosheets (RGOs) under ambient temperature, where octylphenoxypolye thoxyethanol (NP-40) is used as a soft template, without any seed, organic solvent or special instruments. The as-prepared nanocomposites display enhanced electrocatalytic activity and good stability toward methanol oxidation, compared with commercial Pd/C and Pt/C catalysts. This strategy may open a new route to design and prepare advanced electrocatalysts for fuel cells.

  3. Synthesis, characterization and antibacterial effect of new magnetically core–shell nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Allafchian, Alireza, E-mail: Allafchian@cc.iut.ac.ir [Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of); Bahramian, Hamid [Department of physics, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of); Hossein Jalali, Seyed Amir [Institute of Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of); Ahmadvand, Hossein [Department of physics, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of)

    2015-11-15

    A new magnetically responsive three-component nanocomposite consisting of NiFe{sub 2}O{sub 4}, Poly Acrylonitrile Co Maleic Anhydride (PAMA) and nanosilver was synthesized and characterized and then its antibacterial activities were tested. For the preparation of NiFe{sub 2}O{sub 4}@Ag, NiFe{sub 2}O{sub 4} was coated by Ag and for the synthesis of NiFe{sub 2}O{sub 4}@PAMA@Ag, NiFe{sub 2}O{sub 4} was first covered by PAMA and then silver nanoparticles were immobilized on the surface of the PAMA shell. The nanocomposites were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The antibacterial activity of the synthesized nanocomposite against some gram positive and gram negative bacteria was studied and compared with that of naked NiFe{sub 2}O{sub 4}, NiFe{sub 2}O{sub 4}@Ag and NiFe{sub 2}O{sub 4}@PAMA. The NiFe{sub 2}O{sub 4}@PAMA@Ag had better antibacterial activity and could be readily isolated from the aqueous solution via magnetic decantation, thereby avoiding the contamination of the environment. - Highlights: • A novel NiFe{sub 2}O{sub 4}@PAMA@Ag nanocomposites magnetic composite has been prepared. • This system display potent antimicrobial activity toward some bacterial species. • The antibacterial effect was studied by disk diffusion method. • This composite can be easily removed from solution by magnetic decantation.

  4. Synthesis and optical properties of CdS/PVA nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, P K [Nanomaterials Laboratory, Centre for Materials for Electronics Technology (C-MET), Panchawati, Off Pashan Road, Pune 411008 (India); Gokhale, R R [Nanomaterials Laboratory, Centre for Materials for Electronics Technology (C-MET), Panchawati, Off Pashan Road, Pune 411008 (India); Subbarao, V V.V.S. [Nanomaterials Laboratory, Centre for Materials for Electronics Technology (C-MET), Panchawati, Off Pashan Road, Pune 411008 (India); Singh, Narendra [Nanomaterials Laboratory, Centre for Materials for Electronics Technology (C-MET), Panchawati, Off Pashan Road, Pune 411008 (India); Jun, K -W [Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of); Das, B K [Nanomaterials Laboratory, Centre for Materials for Electronics Technology (C-MET), Panchawati, Off Pashan Road, Pune 411008 (India)

    2005-12-15

    Yellow and orange light emission from nanoparticles of cadmium sulphide embedded in polyvinyl alcohol (PVA) has been observed as thin films. The synthesis of CdS embedded in PVA has been performed via two different routes at room temperature and the composite films have been prepared by vacuum evaporation of solvent on a glass surface. The absorption spectra show a blue shift of more than 80 nm as compared to bulk CdS band-gap. The photoluminescence studies indicate the air stable light emission from the films. Bright light emission at 515 nm (2.41 eV) has been observed without using PVA.

  5. Synthesis of redox polymer nanobeads and nanocomposites for glucose biosensors.

    Science.gov (United States)

    Wang, Jen-Yuan; Chen, Lin-Chi; Ho, Kuo-Chuan

    2013-08-28

    Redox polymer nanobeads of branched polyethylenimine binding with ferrocene (BPEI-Fc) were synthesized using a simple chemical process. The functionality and morphology of the redox polymer nanobeads were investigated by Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). This hydrophilic redox nanomaterial could be mixed with glucose oxidase (GOx) for drop-coating on a screen-printed carbon electrode (SPCE) for glucose sensing application. Electrochemical properties of the BPEI-Fc/GOx/SPCE prepared under different conditions were studied by cyclic voltammetry (CV). On the basis of these CV results, the synthetic condition of the BPEI-Fc/GOx/SPCE could be optimized. By incorporating conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the performance of a redox polymer nanobead–based enzyme electrode could be further improved. The influence of PEDOT:PSS on the nanocomposite enzyme electrode was discussed from the aspects of the apparent electron diffusion coefficient (D(app)) and the charge transfer resistance (R(ct)). The glucose-sensing sensitivity of the BPEI-Fc/PEDOT:PSS/GOx/SPCE is calculated to be 66 μA mM(–1) cm(–2), which is 2.5 times higher than that without PEDOT:PSS. The apparent Michaelis constant (K(M)(app)) of the BPEI-Fc/PEDOT:PSS/GOx/SPCE estimated by the Lineweaver–Burk plot is 2.4 mM, which is much lower than that of BPEI-Fc/GOx/SPCE (11.2 mM). This implies that the BPEI-Fc/PEDOT:PSS/GOx/SPCE can catalytically oxidize glucose in a more efficient way. The interference test was carried out by injection of glucose and three common interferences: ascorbic acid (AA), dopamine (DA), and uric acid (UA) at physiological levels. The interferences of DA (4.2%) and AA (7.8%) are acceptable and the current response to UA (1.6%) is negligible, compared to the current response to glucose.

  6. A facile one-pot hydrothermal approach for the preparation of CuO/rGO nanocomposites with different morphologies

    Science.gov (United States)

    Ajit, Akshata V.; Gawli, Yogesh P.; Ethiraj, Anita Sagadevan

    2018-05-01

    Graphene-based metal oxides such as Cu2O, SnO2, CuO, Fe3O4, MnO2 are promising candidates for many applications because of their advantageous properties. Amongst all, CuO has been widely studied because of its excellent electrocatalytic activity. Although many methodologies have been developed for the synthesis of CuO/graphene nanostructures with different morphologies including nanorods, nanoparticles, nanosheets, flower, urchin; not many investigations have been done on one pot synthesis method for CuO/reduced graphene oxide (rGO) nanocomposites to achieve different morphologies. Therefore in the present work effort has been made to synthesize various CuO-rGO nanocomposites via surfactant (CTAB) assisted hydrothermal method. Detailed study was performed to monitor the effect of various reaction parameters like temperature, reaction time, reactant concentration on the synthesized nanocomposites. Several analytical tools, including XRD, SEM, FTIR and UV-Vis spectroscopy have been utilized to characterize the samples. XRD results showed formation of monoclinic structure of CuO along with presence of rGO. Calculated optical bandgap studies indicate decrease in the bandgap of synthesized CuO (Eg=4.5eV-4.34eV) with increase in temperature from 120°C to 180°C. Our results clearly demonstrate that reaction parameters play a key role to bring out the optical and morphological changes in the CuO-rGO nanocomposites.

  7. Synthesis, fabrication and characterization of magnetic and dielectric nanoparticles and nanocomposite films

    Science.gov (United States)

    Liu, Xiaohua

    Materials science is an interdisciplinary field investigating the structure-property relationship in solid-state materials scientifically and technologically. Nanoscience is concerned with the distinctive properties that matter exhibits when confined to physical dimensions on the order of 10-9 meters. At these length scales, behaviors of particles or elaborate structures are often governed by the rules of quantum mechanics in addition to the physical properties associated with the bulk material. The work reported here seeks to employ nanocystals, binary nanocomposites and thin films of materials, to build versatile, functional systems and devices. With a focus on dielectric, ferroelectric, and magnetoelectric performance, a series of materials has been synthesized and different types of nanocomposites have been built. Barium strontium titannate particles at various sizes was developed, aiming at high dielectric constant and low loss at high frequency range. Cobalt ferrite-polymer nanocomposite was fabricated with potential magnetoelectric coupling. Along with synthesis, advanced electron microscopies (TEM, SEM, STEM, EELS) at atomic resolution were employed to thoroughly investigate the crystallinity, morphology and composition. By means of spin-coating and printing techniques, single and multiple layered capacitors featuring improved dielectric performance (high k, low loss, high breakdown voltage, etc.) were developed through a) electrode deposition, b) dielectric layer deposition, and c) parylene evaporation. Such capacitors are further incorporated into electric power converters for LED lighting. Hopefully in the future we can make electronic devices more efficient, sustainable, smaller and cheaper. By advancing our knowledge of nanomaterials, especially those with potential of multifunction, energy efficiency and sustainability, we have strived to push the limits of synthesis, characterization, fabrication and property analysis of nanostructures towards new

  8. Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

    Science.gov (United States)

    Xia, Yijie; Jiang, Xiaoyu; Zhang, Jing; Lin, Ming; Tang, Xiaosheng; Zhang, Jie; Liu, Hongjun

    2017-02-01

    Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV-vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

  9. Infrared heating mediated synthesis and characterization of FeCo/C nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Karpenkov, Dmitriy Yu., E-mail: Karpenkov_dmitriy@yahoo.com [National University of Science and Technology “MISiS”, 119991 Moscow (Russian Federation); Technical University of Darmstadt, 64289 Darmstadt (Germany); Muratov, Dmitriy G. [National University of Science and Technology “MISiS”, 119991 Moscow (Russian Federation); A.V.Topchiev Institute of Petrochemical Synthesis, RAS, 119991 Moscow (Russian Federation); Kozitov, Lev V. [National University of Science and Technology “MISiS”, 119991 Moscow (Russian Federation); Skokov, Konstantin P. [Technical University of Darmstadt, 64289 Darmstadt (Germany); Karpenkov, Alexey Yu. [Chelyabinsk State University, 454001 Chelyabinsk (Russian Federation); Tver State University, 170100 Tver (Russian Federation); Popkova, Alena V. [Tver State University, 170100 Tver (Russian Federation); Gutfleisch, Oliver [Technical University of Darmstadt, 64289 Darmstadt (Germany)

    2017-05-01

    Metal-filled carbon nanocomposites containing 20 wt% of metallic FeCo nanoparticles were synthesized by means of infrared heating of precursors (polyacrylonitrile – iron acetylacetonate - cobalt acetate). This fabrication approach shows promise for making radiation-absorbent materials in short one-step process with ability to control the size of nanoparticles and attune the composition of the metallic components. In this work the magnetic behavior of reaction products obtained at different stages of the synthesis have been investigated in detail. We report on the influence of the annealing temperature on evolution of the structure, chemical composition, size, surface morphology, spontaneous magnetization and coercivity of the FeCo nanoparticles. - Highlights: • A method of preparation of FeCo metal-filled carbon nanocomposites was proposed. • Proposed method is based on infrared heating of the precursors. • This technique excels at up scaling and the ability to control the particle size. • Usage of IR radiation leads to significant reduction of process time and temperature. • The influence of the synthesis parameters on physical properties was studied.

  10. Microwave-polyol synthesis and electrocatalytic performance of Pt/graphene nanocomposites

    International Nuclear Information System (INIS)

    Liao, Chien-Shiun; Liao, Chien-Tsao; Tso, Ching-Yu; Shy, Hsiou-Jeng

    2011-01-01

    Highlights: · One-pot microwave-polyol synthesis of Pt/graphene electrocatalyst. · Simultaneous formation of Pt nanoparticles and reduction of graphene oxide. · Electrocatalytic activities depend on the morphology of the deposited Pt particles. · Dense dispersion of isolated Pt particles with high electrochemical active surface. · Few particle clusters of Pt have large number of active sites for methanol oxidation. - Abstract: Graphene oxide (GO) prepared by the modified Hummers method is used as a support in the formation of a Pt/GO nanocomposite electrocatalyst by microwave-polyol synthesis. The effects of microwave reaction times on particle size, dispersion, and electrocatalytic performance of Pt nanoparticles are studied using wide-angle X-ray diffractometery, Raman spectroscopy, transmission electron microscopy and three-electrode electrochemical measurements. The results indicate that Pt nanoparticles nucleation and growth occur, and the particles are uniformly deposited on the GO nanosheets within a short time. The maximum electrochemical active surface area 85.71 m 2 g -1 for a Pt/GO reaction time of 5 min, is a result of the deposition of a dense dispersion of small Pt particles. The highest methanol oxidation peak current density, I f , of 0.59 A mg -1 occurs for a Pt/GO reaction time of 10 min and is due to the formation of interconnecting Pt particles clusters. This novel Pt/GO nanocomposite electrocatalyst with high electrocatalytic activities has the potential for use as an anode material in fuel cells.

  11. Radiation induced synthesis of conducting polymers and their metal nano-composites

    International Nuclear Information System (INIS)

    Cui, Zhenpeng

    2017-01-01

    The aim of the present work is to demonstrate the versatility of the gamma (γ)-rays based radiolytic method and to extend our methodology to the synthesis of various conducting polymers (CPs) in water in different experimental conditions. Poly(3,4-ethylenedioxy-thiophene) (PEDOT) and poly-pyrrole (PPy) conjugated polymers were successfully prepared and characterized in solution and after deposition by complementary spectroscopic and microscopic techniques. Also their thermal stability and their electrical conductivity were studied and compared with those of CPs prepared by conventional methods. The influence of the nature of radiation-induced oxidizing radicals, of the ionic strength, of the medium, of the pH, of the presence of surfactant-based soft templates on the growth mechanism, on the efficiency of polymerization, on the morphology of the obtained CPs as well as on their absorption and conducting properties was checked. Also, the radiolytic method was extend to the synthesis of CPs/noble metal nano-composites. Different preparation methodologies were developed based on two-step method and one-pot method, by using oxidation route or reduction route. Our new radiolytic strategy described and extended in this manuscript opens the way for the preparation of different kinds of CPs and CPs nano-composites not only in aqueous solutions but also in various environments foreshadowing many promising applications.. (author)

  12. Synthesis of multifunctional clustered nano-Fe3O4 chitosan nanocomposite for biomedical applications

    Science.gov (United States)

    Villamin, Maria Emma; Kitamoto, Yoshitaka

    2018-01-01

    Clustered iron oxide nanoparticles covered with chitosan hydrogel (FeOx/Ch NC) have multiple potential functionalities in biomedical applications such as pH-controlled drug release, magnetic hyperthermia, and magnetic non-contact pH sensing. In the present study, the synthesis and characterization of FeOx/Ch NC are demonstrated. Moreover, the heating capability of the nanocomposites is also explored for the potential magnetic hyperthermia application by measuring the temperature curves under different AC frequencies (900 kHz to 2500 kHz). Monodispersed FeOx NPs are first synthesized via thermal decomposition. Then, dried FeOx NPs are combined with chitosan using a homogenizer to form the clustered composites. Synthesized composites are then characterized using XRD, TEM, and FTIR. Temperature curves are measured via a custom-built hyperthermia setup. Results show successful synthesis of clustered Fe3O4-chitosan nanocomposite with XRD peaks corresponding to magnetite (Fe3O4) structure. FTIR results show the presence of functional groups of chitosan (N-H, C-O) and FeOx NPs (Fe-O). These confirms the successful fabrication of FeOx/Ch NC. The temperature curves show maximum temperature changes of about 2°C to 22°C depending on the AC frequency. The heating rate is found to increase with the frequency, which suggests that the resonance frequency is higher than 2500 kHz.

  13. Synthesis of Polyimides in Molecular-Scale Confinement for Low-Density Hybrid Nanocomposites.

    Science.gov (United States)

    Isaacson, Scott G; Fostvedt, Jade I; Koerner, Hilmar; Baur, Jeffery W; Lionti, Krystelle; Volksen, Willi; Dubois, Geraud; Dauskardt, Reinhold H

    2017-11-08

    In this work, we exploit a confinement-induced molecular synthesis and a resulting bridging mechanism to create confined polyimide thermoset nanocomposites that couple molecular confinement-enhanced toughening with an unprecedented combination of high-temperature properties at low density. We describe a synthesis strategy that involves the infiltration of individual polymer chains through a nanoscale porous network while simultaneous imidization reactions increase the molecular backbone stiffness. In the extreme limit where the confinement length scale is much smaller than the polymer's molecular size, confinement-induced molecular mechanisms give rise to exceptional mechanical properties. We find that polyimide oligomers can undergo cross-linking reactions even in such molecular-scale confinement, increasing the molecular weight of the organic phase and toughening the nanocomposite through a confinement-induced energy dissipation mechanism. This work demonstrates that the confinement-induced molecular bridging mechanism can be extended to thermoset polymers with multifunctional properties, such as excellent thermo-oxidative stability and high service temperatures (>350 °C).

  14. Ferroferric oxide/polystyrene (Fe3O4/PS superparamagnetic nanocomposite via facile in situ bulk radical polymerization

    Directory of Open Access Journals (Sweden)

    2010-03-01

    Full Text Available Organo-modified ferroferric oxide superparamagnetic nanoparticles, synthesized by the coprecipitation of superparamagnetic nanoparticles in presence of oleic acid (OA, were incorporated in polystyrene (PS by the facile in situ bulk radical polymerization by using 2,2-azobisisobutyronitrile (AIBN as initiator. The transmission electron microscopy (TEM analysis of the resultant uniform ferroferric oxide/polystyrene superparamagnetic nanocomposite (Fe3O4/PS showed that the superparamagnetic nanoparticles had been dispersed homogeneously in the polymer matrix due to the surface grafted polystyrene, confirmed by Fourier transform infrared (FT-IR spectroscopy and thermogravimetric analysis (TGA. The superparamagnetic property of the Fe3O4/PS nanocomposite was testified by the vibrating sample magnetometer (VSM analysis. The strategy developed is expected to be applied for the large-scale industrial manufacturing of the superparamagnetic polymer nanocomposite.

  15. Hydrothermal synthesis of TiO2-ZnO-graphene nanocomposite towards photocatalytic and photovoltaic applications

    International Nuclear Information System (INIS)

    Gayathri, S.; Jayabal, P.; Ramakrishnan, V.

    2015-01-01

    Titanium dioxide (TiO 2 ) - Zinc oxide (ZnO) - Graphene (G) nanocomposite was successfully synthesized through facile hydrothermal method. The X-ray diffraction (XRD) pattern and the micro-Raman spectroscopic technique revealed the formation of TiO 2 -ZnO-Graphene (TZG) nanocomposite. The ZnO and TiO 2 nanoparticles decorated graphene sheets were clearly noticeable in the Field Emission Scanning Electron Micrograph (FE-SEM). The UV-Visible absorption spectra clearly indicated that the formation of TZG nanocomposite enriched the absorption in the visible region. Hence, the prepared nanocomposite can be used as photocatalyst to remove organic dyes from water and as photoanode in the fabrication of dye sensitized solar cells (DSSCs)

  16. Hydrothermal synthesis of TiO2-ZnO-graphene nanocomposite towards photocatalytic and photovoltaic applications

    Science.gov (United States)

    Gayathri, S.; Jayabal, P.; Ramakrishnan, V.

    2015-06-01

    Titanium dioxide (TiO2) - Zinc oxide (ZnO) - Graphene (G) nanocomposite was successfully synthesized through facile hydrothermal method. The X-ray diffraction (XRD) pattern and the micro-Raman spectroscopic technique revealed the formation of TiO2-ZnO-Graphene (TZG) nanocomposite. The ZnO and TiO2 nanoparticles decorated graphene sheets were clearly noticeable in the Field Emission Scanning Electron Micrograph (FE-SEM). The UV-Visible absorption spectra clearly indicated that the formation of TZG nanocomposite enriched the absorption in the visible region. Hence, the prepared nanocomposite can be used as photocatalyst to remove organic dyes from water and as photoanode in the fabrication of dye sensitized solar cells (DSSCs).

  17. Hydrothermal synthesis of TiO{sub 2}-ZnO-graphene nanocomposite towards photocatalytic and photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Gayathri, S., E-mail: s.gayathri1010@gmail.com; Jayabal, P. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai-625021 (India); Ramakrishnan, V. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai-625021 (India); Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram-695016 (India)

    2015-06-24

    Titanium dioxide (TiO{sub 2}) - Zinc oxide (ZnO) - Graphene (G) nanocomposite was successfully synthesized through facile hydrothermal method. The X-ray diffraction (XRD) pattern and the micro-Raman spectroscopic technique revealed the formation of TiO{sub 2}-ZnO-Graphene (TZG) nanocomposite. The ZnO and TiO{sub 2} nanoparticles decorated graphene sheets were clearly noticeable in the Field Emission Scanning Electron Micrograph (FE-SEM). The UV-Visible absorption spectra clearly indicated that the formation of TZG nanocomposite enriched the absorption in the visible region. Hence, the prepared nanocomposite can be used as photocatalyst to remove organic dyes from water and as photoanode in the fabrication of dye sensitized solar cells (DSSCs)

  18. Biomolecule-assisted synthesis of Ag/reduced graphene oxide nanocomposite with excellent electrocatalytic and antibacterial performance

    Energy Technology Data Exchange (ETDEWEB)

    Fathalipour, Soghra, E-mail: fathalipour@pnu.ac.ir [Department of Chemistry, Payame Noor University, PO Box: 19395-3697, Tehran (Iran, Islamic Republic of); Pourbeyram, Sima; Sharafian, Aziaeh [Department of Chemistry, Payame Noor University, PO Box: 19395-3697, Tehran (Iran, Islamic Republic of); Tanomand, Asghar [Department of Basic Sciences, Faculty Of Medicine, Maragheh University of Medical Sciences, PO Box: 78151-55158 (Iran, Islamic Republic of); Azam, Parisa [Department of Chemistry, Payame Noor University, PO Box: 19395-3697, Tehran (Iran, Islamic Republic of)

    2017-06-01

    In this work, an environmentally friendly method was applied for the synthesis of aqueous suspension of L-cysteine modified Ag nanoparticles (NPs)-decorated reduced graphene oxide (rGO) nanocomposite. L-cysteine played a triple role as reducing agent, stabilizer and linker of Ag NPs onto the surface of rGO. The resultant nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction studies (XRD), zeta potential, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDX). Meanwhile, minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC), agar well diffusion and cyclic voltammetry (CV) techniques were used for the investigation of antibacterial and electrocatalytic behaviors of the nanocomposite, respectively. The obtained nanocomposite showed not only enhanced electrocatalytic activity for glucose but also excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). - Highlights: • Biocompatible reduced graphene oxide/ Ag nanocomposite was synthesized based on cysteine- Ag nanoparticles. • The reaction was carried out at room temperature without any further reducer. • The nanocomposite displayed excellent antibacterial and electrocatalytic activity against glucose.

  19. Facile and Green Synthesis of Saturated Cyclic Amines

    Directory of Open Access Journals (Sweden)

    Arruje Hameed

    2017-10-01

    Full Text Available Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

  20. Synthesis of reduced graphene oxide-anatase TiO2 nanocomposite and its improved photo-induced charge transfer properties.

    Science.gov (United States)

    Wang, Ping; Zhai, Yueming; Wang, Dejun; Dong, Shaojun

    2011-04-01

    The construction of reduced graphene oxide or graphene oxide with semiconductor has gained more and more attention due to its unexpected optoelectronic and electronic properties. The synthesis of reduced graphene oxide (RGO) or graphene oxide-semiconductor nanocomposite with well-dispersed decorated particles is still a challenge now. Herein, we demonstrate a facile method for the synthesis of graphene oxide-amorphous TiO(2) and reduced graphene oxide-anatase TiO(2) nanocomposites with well-dispersed particles. The as-synthesized samples were characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis absorption spectroscopy, Fourier transform infrared spectrometry, and thermogravimetric analysis. The photovoltaic properties of RGO-anatase TiO(2) were also compared with that of similar sized anatase TiO(2) by transient photovoltage technique, and it was interesting to find that the combination of reduced graphene oxide with anatase TiO(2) will significantly increase the photovoltaic response and retard the recombination of electron-hole pairs in the excited anatase TiO(2).

  1. Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yijie [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Jiang, Xiaoyu; Zhang, Jing [AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore); Lin, Ming [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); Tang, Xiaosheng [AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore); Zhang, Jie, E-mail: zhangj@imre.a-star.edu.sg [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); Liu, Hongjun, E-mail: hjliu@henu.edu.cn [Key Laboratory of Natural Medicine and Immuno-Engineering of Henan Province, Henan University, Kaifeng, Henan 475004 (China); AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore)

    2017-02-28

    Highlights: • Nanosilver diatomite has been developed with a facile, easy and effective in–situ reduction method. • The nanosilver diatomite demonstrated great antibacterial properties to gram positive and gram–negative bacterial. • A small amount of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. • Low cost nano–composite antimicrobial material for water purification industry. - Abstract: Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV–vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

  2. Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

    International Nuclear Information System (INIS)

    Xia, Yijie; Jiang, Xiaoyu; Zhang, Jing; Lin, Ming; Tang, Xiaosheng; Zhang, Jie; Liu, Hongjun

    2017-01-01

    Highlights: • Nanosilver diatomite has been developed with a facile, easy and effective in–situ reduction method. • The nanosilver diatomite demonstrated great antibacterial properties to gram positive and gram–negative bacterial. • A small amount of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. • Low cost nano–composite antimicrobial material for water purification industry. - Abstract: Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV–vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

  3. Facile Synthesis of N -Substituted Benzimidazoles

    NARCIS (Netherlands)

    Kurhade, Santosh; Rossetti, Arianna; Dömling, Alexander

    2016-01-01

    A particularly mild and efficient one-pot synthesis of N-substituted benzimidazole derivatives was developed. 2-Fluoro-5-nitrophenylisocyanide reacts with a diverse set of primary amines to afford the respective products in moderate to very good yield (35-95%; 20 examples).

  4. Mechanism of Particle Formation in Silver/Epoxy Nanocomposites Obtained through a Visible-Light-Assisted in Situ Synthesis.

    Science.gov (United States)

    dell'Erba, Ignacio E; Martínez, Francisco D; Hoppe, Cristina E; Eliçabe, Guillermo E; Ceolín, Marcelo; Zucchi, Ileana A; Schroeder, Walter F

    2017-10-03

    A detailed understanding of the processes taking place during the in situ synthesis of metal/polymer nanocomposites is crucial to manipulate the shape and size of nanoparticles (NPs) with a high level of control. In this paper, we report an in-depth time-resolved analysis of the particle formation process in silver/epoxy nanocomposites obtained through a visible-light-assisted in situ synthesis. The selected epoxy monomer was based on diglycidyl ether of bisphenol A, which undergoes relatively slow cationic ring-opening polymerization. This feature allowed us to access a full description of the formation process of silver NPs before this was arrested by the curing of the epoxy matrix. In situ time-resolved small-angle X-ray scattering investigation was carried out to follow the evolution of the number and size of the silver NPs as a function of irradiation time, whereas rheological experiments combined with near-infrared and ultraviolet-visible spectroscopies were performed to interpret how changes in the rheological properties of the matrix affect the nucleation and growth of particles. The analysis of the obtained results allowed us to propose consistent mechanisms for the formation of metal/polymer nanocomposites obtained by light-assisted one-pot synthesis. Finally, the effect of a thermal postcuring treatment of the epoxy matrix on the particle size in the nanocomposite was investigated.

  5. In situ synthesis of magnetic CaraPVA IPN nanocomposite hydrogels and controlled drug release

    International Nuclear Information System (INIS)

    Mahdavinia, Gholam Reza; Etemadi, Hossein

    2014-01-01

    In this work, the magnetic nanocomposite hydrogels that focused on targeted drug delivery were synthesized by incorporation of polyvinyl alcohol (PVA), kappa-carrageenan (Cara), and magnetite Fe 3 O 4 nanoparticles. The magnetic nanoparticles were obtained in situ in the presence of a mixture of polyvinyl alcohol/kappa-carrageenan (CaraPVA). The produced magnetite-polymers were cross-linked with freezing–thawing technique and subsequent with K + solution. The synthesized hydrogels were thoroughly characterized by transmittance electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. The dynamic swelling kinetic models of hydrogels were analyzed according to the first- and second-order kinetic models and were found that the experimental kinetics data followed the second-order model well. Drug loading and release efficiency were evaluated by diclofenac sodium (DS) as the model drug. The in vitro drug release studies from hydrogels exhibited significant behaviors on the subject of physiological simulated pHs and external magnetic fields. Investigation on the antibacterial activity revealed the ability of drug-loaded hydrogels to inactivate the Gram-positive Staphylococcus aureus (S. aureus) bacteria. The mucoadhesive properties of the hydrogels were studied and the hydrogels containing kappa-carrageenan showed good mucoadhesiveness in both simulated gastric and intestinal conditions. - Highlights: • In situ synthesis of magnetic kappa-carrageenan/PVA nanocomposite hydrogel. • Low salt sensitivity of magnetic nanocomposite hydrogels was observed. • The release of diclofenac sodium from hydrogels was pH-dependent. • The release of diclofenac sodium from magnetic hydrogels was affected by external magnetic field. • The hydrogels containing carrageenan component showed high mucoadhesiveness

  6. In situ synthesis of magnetic CaraPVA IPN nanocomposite hydrogels and controlled drug release

    Energy Technology Data Exchange (ETDEWEB)

    Mahdavinia, Gholam Reza, E-mail: grmnia@maragheh.ac.ir; Etemadi, Hossein

    2014-12-01

    In this work, the magnetic nanocomposite hydrogels that focused on targeted drug delivery were synthesized by incorporation of polyvinyl alcohol (PVA), kappa-carrageenan (Cara), and magnetite Fe{sub 3}O{sub 4} nanoparticles. The magnetic nanoparticles were obtained in situ in the presence of a mixture of polyvinyl alcohol/kappa-carrageenan (CaraPVA). The produced magnetite-polymers were cross-linked with freezing–thawing technique and subsequent with K{sup +} solution. The synthesized hydrogels were thoroughly characterized by transmittance electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. The dynamic swelling kinetic models of hydrogels were analyzed according to the first- and second-order kinetic models and were found that the experimental kinetics data followed the second-order model well. Drug loading and release efficiency were evaluated by diclofenac sodium (DS) as the model drug. The in vitro drug release studies from hydrogels exhibited significant behaviors on the subject of physiological simulated pHs and external magnetic fields. Investigation on the antibacterial activity revealed the ability of drug-loaded hydrogels to inactivate the Gram-positive Staphylococcus aureus (S. aureus) bacteria. The mucoadhesive properties of the hydrogels were studied and the hydrogels containing kappa-carrageenan showed good mucoadhesiveness in both simulated gastric and intestinal conditions. - Highlights: • In situ synthesis of magnetic kappa-carrageenan/PVA nanocomposite hydrogel. • Low salt sensitivity of magnetic nanocomposite hydrogels was observed. • The release of diclofenac sodium from hydrogels was pH-dependent. • The release of diclofenac sodium from magnetic hydrogels was affected by external magnetic field. • The hydrogels containing carrageenan component showed high

  7. Facile Synthesis of Permethyl Yttrocene Hydride

    NARCIS (Netherlands)

    Haan, Klaas H. den; Teuben, Jan H.

    1984-01-01

    A convenient three step synthesis of (Cp*2YH)n (Cp* = C5Me5) is described starting with YCl3.3thf, in which Cp*2YCl.thf and Cp*2YCH(SiMe3)2 are intermediates, which could be isolated and characterized. The hydride is active in the activation of sp2 and sp3 C-H bonds as was demonstrated by the H-D

  8. Microwave assisted facile hydrothermal synthesis and characterization of zinc oxide flower grown on graphene oxide sheets for enhanced photodegradation of dyes

    International Nuclear Information System (INIS)

    Kashinath, L.; Namratha, K.; Byrappa, K.

    2015-01-01

    Graphical abstract: - Highlights: • Synthesis of hybrid ZnO–GO nanocomposite via microwave assisted facile hydrothermal method. • The in situ flower like ZnO nano particles are densely decorated and anchored on the surfaces of graphene oxide sheets. • They exhibited high adsorption measurement, increase in surface area and meso/micro porous in nature. • The structure and morphology plays a vital role in enhancing the photo response activities of degradation of dyes. - Abstract: Microwave assisted hydrothermal process of synthesis of ZnO–GO nanocomposite by using ZnCl 2 and NaOH as precursors is being reported first time. In this investigation, a novel route to study on synthesis, interaction, kinetics and mechanism of hybrid zinc oxide–graphene oxide (ZnO–GO) nanocomposite using microwave assisted facile hydrothermal method has been reported. The results shows that the ZnO–GO nanocomposite exhibits an enhancement and acts as stable photo-response degradation performance of Brilliant Yellow under the UV light radiation better than pure GO and ZnO nanoparticles. The microwave exposure played a vital role in the synthesis process, it facilitates with well define crystalline structure, porosity and fine morphology of ZnO/GO nanocomposite. Different molar concentrations of ZnO precursors doped to GO sheets were been synthesized, characterized and their photodegradation performances were investigated. The optical studies by UV–vis and Photo Luminescence shows an increase in band gap of nanocomposite, which added an advantage in photodegradation performance. The in situ flower like ZnO nano particles are were densely decorated and anchored on the surfaces of graphene oxide sheets which aids in the enhancement of the surface area, adsorption, mass transfer of dyes and evolution of oxygen species. The nanocomposite having high surface area and micro/mesoporous in nature. This structure and morphology supports significantly in increasing photo catalytic

  9. Synthesis of Platinum-Nickel Hydroxide Nanocomposites for Electrocatalytic Reduction of Water

    KAUST Repository

    Wang, Lei

    2016-11-25

    Water electrolysis represents a promising solution for storage of renewable but intermittent electrical energy in hydrogen molecules. This technology is however challenged by the lack of efficient electrocatalysts for the hydrogen and oxygen evolution reactions. Here we report on the synthesis of platinum-nickel hydroxide nanocomposites and their electrocatalytic applications for water reduction. An in situ reduction strategy taking advantage of the Ni(II)/Ni(III) redox has been developed to enable and regulate the epitaxial growth of Pt nanocrystals on single-layer Ni(OH)2 nanosheets. The obtained nanocomposites (denoted as Pt@2D-Ni(OH)2) exhibit an improvement factor of 5 in catalytic activity and a reduction of up to 130 mV in overpotential compared to Pt for the hydrogen evolution reaction (HER). A combination of electron microscopy/spectroscopy characterization, electrochemical studies and density functional calculations was employed to uncover the structures of the metal-hydroxide interface and understand the mechanisms of catalytic enhancement.

  10. Synthesis and characterization of a nanocomposite of goethite nanorods and reduced graphene oxide for electrochemical capacitors

    International Nuclear Information System (INIS)

    Shou Qingliang; Cheng Jipeng; Zhang Li; Nelson, Bradley J.; Zhang Xiaobin

    2012-01-01

    We report a one-step synthesis of a nanocomposite of goethite (α-FeOOH) nanorods and reduced graphene oxide (RGO) using a solution method in which ferrous cations serve as a reducing agent of graphite oxide (GO) to graphene and a precursor to grow goethite nanorods. As-prepared goethite nanorods have an average length of 200 nm and a diameter of 30 nm and are densely attached on both sides of the RGO sheets. The electrochemical properties of the nanocomposite were characterized by cyclic voltammetry (CV) and chronopotentiometry (CP) charge–discharge tests. The results showed that goethite/RGO composites have a high electrochemical capacitance of 165.5 F g −1 with an excellent recycling capability making the material promising for electrochemical capacitors. - Graphical abstract: The reduced graphene oxide sheets are decorated with goethite nanorods. The as-prepared composite exhibits a high electrochemical capacitance with good recycling capability, which is promising for supercapacitor applications. Higlights: ► Ferrous ions act as reductant of graphite oxide and precursor of goethite nanorods. ► Goethite nanorods are attached on both sides of the reduced graphene oxide sheets. ► Composite exhibits a high specific capacitance and a good recycling capability. ► Composite is promising for supercapacitor applications.

  11. Enhanced photocatalytic activity of ZnO–graphene nanocomposites prepared by microwave synthesis

    International Nuclear Information System (INIS)

    Herring, Natalie P.; Almahoudi, Serial H.; Olson, Chelsea R.; El-Shall, M. Samy

    2012-01-01

    This work reports a simple one-step synthesis of ZnO nanopyramids supported on reduced graphene oxide (RGO) nanosheets using microwave irradiation (MWI) of zinc acetate and GO in the presence of a mixture of oleic acid and oleylamine. The rapid decomposition of zinc acetate by MWI in the presence of the mixture of oleic acid and oleylamine results in the formation of hexagonal ZnO nanopyramids. GO has a high affinity for absorbing MWI, which results in a high local heating effect around the GO nanosheets and facilitates the reduction of GO by the oleylamine. The RGO nanosheets act as heterogeneous surface sites for the nucleation and growth of the ZnO nanopyramids. Using ligand exchange, the ZnO–RGO nanocomposites can be dispersed in an aqueous medium, thus allowing their use as photocatalysts for the degradation of the malachite green dye in water. The ZnO–RGO nanocomposites show enhanced photocatalytic activity for the degradation of the dye over the unsupported ZnO nanopyramids. The enhanced activity is attributed to efficient charge transfer of the photogenerated electrons in the conduction band of ZnO to graphene. This enhances the oxidative pathway of the holes generated in the valence band of ZnO which can effectively lead to the degradation and mineralization of the malachite green. The ZnO nanopyramids supported on RGO could have improved performance in other photocatalytic reactions and also in solar energy conversion.

  12. Synthesis of Platinum-Nickel Hydroxide Nanocomposites for Electrocatalytic Reduction of Water

    KAUST Repository

    Wang, Lei; Zhu, Yihan; Zeng, Zhenhua; Lin, Chong; Giroux, Michael; Jiang, Lin; Han, Yu; Greeley, Jeffrey; Wang, Chao; Jin, Jian

    2016-01-01

    Water electrolysis represents a promising solution for storage of renewable but intermittent electrical energy in hydrogen molecules. This technology is however challenged by the lack of efficient electrocatalysts for the hydrogen and oxygen evolution reactions. Here we report on the synthesis of platinum-nickel hydroxide nanocomposites and their electrocatalytic applications for water reduction. An in situ reduction strategy taking advantage of the Ni(II)/Ni(III) redox has been developed to enable and regulate the epitaxial growth of Pt nanocrystals on single-layer Ni(OH)2 nanosheets. The obtained nanocomposites (denoted as Pt@2D-Ni(OH)2) exhibit an improvement factor of 5 in catalytic activity and a reduction of up to 130 mV in overpotential compared to Pt for the hydrogen evolution reaction (HER). A combination of electron microscopy/spectroscopy characterization, electrochemical studies and density functional calculations was employed to uncover the structures of the metal-hydroxide interface and understand the mechanisms of catalytic enhancement.

  13. Synthesis and Examination of Nanocomposites Based on Poly(2-hydroxyethyl methacrylate for Medicinal Use

    Directory of Open Access Journals (Sweden)

    Olena S. Kukolevska

    2017-02-01

    Full Text Available Abstract Preparation of poly(2-hydroxyethyl methacrylate (PHEMA based nanocomposites using different approaches such as synthesis with water as the porogen, filling of polymer matrix by silica and formation of interpenetrating polymer networks with polyurethane was demonstrated. Incorporation of various biologically active compounds (BAC such as metronidazole, decamethoxin, zinc sulphate, silver nitrate or amino acids glycine and tryptophan into nanocomposites was achieved. BAC were introduced into the polymer matrix either (1 directly, or (2 with a solution of colloidal silica, or (3 through immobilization on silica (sol-densil. Morphology of prepared materials was investigated by laser scanning microscopy and low-vacuum scanning electron microscopy. In vacuum freeze-drying, prior imaging was proposed for improving visualization of the porous structure of composites. The interaction between PHEMA matrix and silica filler was investigated by IR spectroscopy. Adsorption of 2-hydroxyethyl methacrylate and BAC from aqueous solution on the silica surface was also examined. Phase composition and thermal stability of composites were studied by the differential thermogravimetry/differential thermal analysis. Release of BAC into water medium from prepared composites were shown to depend on the synthetic method and differed significantly. Obtained PHEMA-base materials which are characterized by controlled release of BAC have a strong potential for application in manufacturing of different surgical devices like implants, catheters and drainages.

  14. Synthesis, Optical, and Magnetic Properties of Graphene Quantum Dots and Iron Oxide Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Sajjad

    2018-01-01

    Full Text Available The combination of nanomaterial graphene quantum dots (GQDs with magnetic nanoparticles offers a unique set of optical and magnetic properties for future energy and medical applications. We report on the synthesis and engineering of GQDs and iron oxide (Fe3O4 nanocomposites (NCs by using a pulsed laser discharge technique. High-resolution transmission electron microscopy (HRTEM images showed a high yield of pure GQDs with 2–10 nm diameter. The hexagonal structures and lattice fringes associated with the C–C bond in GQDs were clearly identifiable. The structural and optical changes in GQDs and GQDs-Fe3O4 NC samples induced by UV light were investigated by the absorption and emission spectroscopy over the deep UV–visible spectral range. The photoluminescence spectra have shown subband π→π∗ transitions in GQDs-Fe3O4 NC. Magnetic properties of the GQDs-Fe3O4 NC samples have shown room temperature ferromagnetism induced by pure Fe3O4 nanoparticles and from the substantial spin polarized edges of GQD nanoparticles. It is concluded that the observed optical and magnetic properties could be further tailored in the studied nanocomposites for prospective medical applications.

  15. One-pot low-temperature green synthesis of magnetic graphene nanocomposite for the selective reduction of nitrobenzene

    Science.gov (United States)

    Haridas, Vijayasree; Sugunan, Sankaran; Narayanan, Binitha N.

    2018-06-01

    In the present study, a green one-pot low-temperature method is adopted for the synthesis of a novel magnetic graphene nanocomposite catalyst. Graphene preparation is performed without employing any oxidizing agents or corrosive chemicals, under mild sonication in isopropyl alcohol - water mixture. Monolayered nanoplatelets of graphene are obtained in the green solvent mixture and the composite material is found to be ferromagnetic in nature, obvious from the vibrating sample magnetometric measurements. Fe in the nanocomposite exists in two different forms i.e., α-Fe2O3 and α-FeOOH, as evident from the material characterization results. The graphene nanocomposite is found to be highly efficient in the selective reduction of nitrobenzene to aniline under solvent free reaction conditions and magnetic separation of this fine nanomaterial from the reaction mixture is successfully carried out. The catalyst is efficiently reusable till five repeated cycles.

  16. Group 12 dithiocarbamate complexes: Synthesis, spectral studies and their use as precursors for metal sulfides nanoparticles and nanocomposites

    Science.gov (United States)

    Ajibade, Peter A.; Ejelonu, Benjamin C.

    2013-09-01

    Zn(II), Cd(II) and Hg(II) dithiocarbamate complexes have been synthesized and characterized by elemental analysis, thermogravimetric analysis, UV-Vis, FTIR, 1H- and 13C NMR spectroscopy. The complexes were thermolysed at 180 °C and used as single molecule precursors for the synthesis of HDA capped ZnS, CdS and HgS nanoparticles and polymethylmethacrylate (PMMA) nanocomposites. The optical and structural properties of the nanoparticles and nanocomposites were studied by UV-Vis, PL, XRD and SEM. The crystallites sizes of the nanoparticles varied between 3.03 and 23.45 nm. SEM and EDX analyses of the nanocomposites confirmed the presence of the nanoparticles in the polymer matrix.

  17. A facile approach for the synthesis of indenoimidazole derivatives ...

    Indian Academy of Sciences (India)

    J. Chem. Sci. Vol. 128, No. 12, December 2016, pp. 1841–1847. c Indian Academy of Sciences. DOI 10.1007/s12039-016-1181-2. A facile approach for the synthesis of ... pounds 1 and 2 are presented here in terms of crystal engineering and supramolecular chemistry. ... zoles are heterocyclic organic compounds of wide.

  18. Synthesis of nanocomposite coating based on TiO2/ZnAl layer double hydroxides

    International Nuclear Information System (INIS)

    Jovanov, V.; Rudic, O.; Ranogajec, J.; Fidanchevska, E.

    2017-01-01

    The aim of this investigation was the synthesis of nanocomposite coatings based on Zn-Al layered double hydroxides (Zn-Al LDH) and TiO2. The Zn-Al LDH material, which acted as the catalyst support of the active TiO2 component (in the content of 3 and 10 wt. %), was synthesized by a low super saturation co-precipitation method. The interaction between the Zn-Al LDH and the active TiO2 component was accomplished by using vacuum evaporation prior to the mechanical activation and only by mechanical activation. The final suspension based on Zn-Al LDH and 10wt. % TiO2, impregnated only by mechanical activation, showed the optimal characteristics from the aspect of particle size distribution and XRD analysis. These properties had a positive effect on the functional properties of the coatings (photocatalytic activity and self-cleaning efficiency) after the water rinsing procedure. [es

  19. Carboxymethylguargum-silver nanocomposite: green synthesis, characterization and an optical sensor for ammonia detection

    International Nuclear Information System (INIS)

    Gupta, Anek Pal; Verma, Devendra Kumar

    2014-01-01

    This work describes the preparation of new carboxymethyl guar gum-silver nanocomposite (CMGG/Ag NC) by green synthesis method. For this carboxymethyl guar gum was used as a reducing agent as well as stabilizer. The silver nanoparticles obtained were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV–vis spectroscopy, Fourier transform infrared (FTIR) and energy dispersive x-ray analysis (EDX). The average size of the silver nanoparticles was found of ∼6 nm. Thus, the obtained CMGG/AgNPs NC was examined for optical sensing property for detection of ammonia in aqueous medium. The response time and the detection limit of ammonia in aqueous solution were detected at room temperature. It was concluded that in the future, at this room temperature optical ammonia sensor may be used for medical diagnosis and clinically for detecting low ammonia level (up to 1 ppm) in biological samples for various biomedical applications. (paper)

  20. Solid-state synthesis and electrical properties of polyaniline/Cu-montmorillonite nanocomposite

    International Nuclear Information System (INIS)

    Bekri-Abbes, Imene; Srasra, Ezzeddine

    2010-01-01

    In this paper, the solid-state synthesis of polyaniline/Cu-montmorillonite nanocomposite is reported. Mixture of anilinium chlorure and Cu exchanged montmorillonite was grinded at room temperature while we vary the molar rate of aniline to interlayer Cu 2+ cations (R) from 0.5 to 6. The properties of the hybrid compounds are characterized by X-ray diffraction, thermogravimetric analysis, SEM, FTIR and impedance spectroscopy. The results showed that the structure and the conductivity of PANI in hybrid materials depend on R. The ac conduction showed a regime of constant dc conductivity at low frequencies and a crossover to a frequency-dependent regime of the type A ω s at high frequencies.

  1. Mechanical synthesis of copper-carbon nanocomposites: Structural changes, strengthening and thermal stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, D., E-mail: daniela.nunes@ist.utl.pt [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); ICEMS, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Livramento, V. [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); Mateus, R. [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Correia, J.B. [LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); Alves, L.C. [ITN, Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Vilarigues, M. [Departamento de Conservacao e Restauro e R and D Unit Vidro e da Ceramica Para as Artes, FCT-UNL, Quinta da Torre, 2829-516 Caparica (Portugal); Carvalho, P.A. [ICEMS, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Departamento de Bioengenharia, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2011-11-15

    Highlights: {yields} The study characterized Cu-nanodiamond (Cu-nD) and Cu-graphite (Cu-G) composites. {yields} Preservation of nD crystalline structure during high-energy milling was demonstrated. {yields} Higher refinement of matrix in Cu-nD comparing to Cu-G is due to a milling mechanism. {yields} Remarkable thermal stability and microhardness have been achieved in Cu-nD and Cu-G. {yields} Strengthening resulted mainly from grain refinement and second-phase reinforcement. - Abstract: Processing of copper-carbon nanocomposites by mechanical synthesis poses specific challenges as carbon phases are prone to amorphization and exhibit an intrinsically difficult bonding with copper. The present work investigates Cu-nanodiamond (Cu-nD) and Cu-graphite (Cu-G) composites produced by mechanical synthesis and subsequent heat treatments. Transmission electron microscopy observations showed homogeneous particle distributions and intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained essentially unaffected by the mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. Particle-induced X-ray emission spectroscopy showed that the total contamination originating from the milling media remained below 0.7 wt.%. The Cu-nanodiamond composite exhibited remarkable microhardness and microstructural thermal stability when compared with pure nanostructured copper.

  2. Mechanical synthesis of copper-carbon nanocomposites: Structural changes, strengthening and thermal stabilization

    International Nuclear Information System (INIS)

    Nunes, D.; Livramento, V.; Mateus, R.; Correia, J.B.; Alves, L.C.; Vilarigues, M.; Carvalho, P.A.

    2011-01-01

    Highlights: → The study characterized Cu-nanodiamond (Cu-nD) and Cu-graphite (Cu-G) composites. → Preservation of nD crystalline structure during high-energy milling was demonstrated. → Higher refinement of matrix in Cu-nD comparing to Cu-G is due to a milling mechanism. → Remarkable thermal stability and microhardness have been achieved in Cu-nD and Cu-G. → Strengthening resulted mainly from grain refinement and second-phase reinforcement. - Abstract: Processing of copper-carbon nanocomposites by mechanical synthesis poses specific challenges as carbon phases are prone to amorphization and exhibit an intrinsically difficult bonding with copper. The present work investigates Cu-nanodiamond (Cu-nD) and Cu-graphite (Cu-G) composites produced by mechanical synthesis and subsequent heat treatments. Transmission electron microscopy observations showed homogeneous particle distributions and intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained essentially unaffected by the mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. Particle-induced X-ray emission spectroscopy showed that the total contamination originating from the milling media remained below 0.7 wt.%. The Cu-nanodiamond composite exhibited remarkable microhardness and microstructural thermal stability when compared with pure nanostructured copper.

  3. Solvothermal synthesis of Zinc sulfide decorated Graphene (ZnS/G) nanocomposites for novel Supercapacitor electrodes

    International Nuclear Information System (INIS)

    Ramachandran, Rajendran; Saranya, Murugan; Kollu, Pratap; Raghupathy, Bala P.C.; Jeong, Soon Kwan; Grace, Andrews Nirmala

    2015-01-01

    Highlights: • ZnS/G nanocomposites were prepared by a simple solvothermal process. • Electrochemical measurements were carried out in 6 M KOH electrolyte. • Cyclic voltammetry showed the excellent capacitive behavior of the composites. • A specific capacitance of 197.1 F/g was observed for ZnS/G-60 nanocomposites. - Abstract: Zinc sulfide decorated graphene nanocomposites are synthesized by a facile solvothermal approach and the prepared composites are analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High Resolution Transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR), Ultraviolet visible spectroscopy (UV), Photoluminescence spectroscopy (PL) and Raman spectrum. Results show the effective reduction of graphene oxide (GO) to graphene and decoration of ZnS nanoparticles on graphene sheets. Towards supercapacitor applications, the electrochemical measurements of different electrodes are performed in 6 M KOH electrolyte. A series of composites with different loadings of graphene is synthesized and tested for its electrochemical properties. The specific capacitance of the electrodes are evaluated from cyclic voltammetry (CV) studies and a maximum specific capacitance of 197.1 F/g is achieved in ZnS/G-60 electrode (60 indicates the weight ratio of GO) at scan rate of 5 mV s"−"1. A capacitance retention of about 94.1% is observed even after 1000 cycles for ZnS/G-60 electrode, suggesting the long time cyclic stability of the composite electrode. Galvanostatic charge–discharge curves show the highly reversible process of ZnS/G-60 electrode. Electrochemical Impedance Spectrum (EIS) shows a high conductivity of composite electrode suggesting that the composites are good candidates for energy storage.

  4. Novel synthesis of Prussian blue nanoparticles and nanocomposite sol: Electro-analytical application in hydrogen peroxide sensing

    International Nuclear Information System (INIS)

    Pandey, Prem C.; Pandey, Ashish K.

    2013-01-01

    Highlights: ► Novel process for the synthesis of PBNPs sol of 15.8 nm size is reported. ► The PBNPs sol shows the electron transfer rate constant to the order of 32.1 s −1 ► The PBNPs sol has shown the functional activity for making the nanocomposite. ► The nanocomposite with tris(2,2′-bipyridyl)ruthenium shows photoluminiscent ability. ► The PBNPs and its nanocomposite (PB-Rubpy) show high sensitivity for H 2 O 2 sensing. - Abstract: This paper reports a new method for the synthesis of Prussian blue nanoparticles (PBNPs) sol of homogeneous dispersion with average particle size to the order of 15.8 nm. The new method of PBNPs sol synthesis is based on the interaction of active concentrations of 3-aminopropylalkoxysilane, cyclohexanone and single precursor potassium ferricyanide under ambient conditions. The PBNPs sol shows excellent electrochemistry with electron transfer rate constant to the order of 32.1 s −1 . The resulting PBNPs sol has been found highly stable for practical applications and shows functional activity for making nanocomposite sol with tris(2,2′-bipyridyl) ruthenium (Rubpy). The PB-Rubpy nanocomposite shows high sensitivity for H 2 O 2 electrochemical sensing to the order of 1102.0 μA mM −1 cm −2 and storage stability of the materials for more than 3 months. In addition, these nanocomposite exhibits excellent electrocatalytic property for hydrogen peroxide (H 2 O 2 ) sensing with catalytic rate constant to the order of 3.14 × 10 3 M −1 s −1 . The PB-Rubpy nanocomposite sol, apart from electrocatalytic application, shows photoluminiscent ability for many opto-electroanalytical applications. In addition to that functional property of PBNPs sol for making nanodispersion with several known nanoparticles of gold, silver, palladium along with in situ synthesis of mixed metal hexacyanoferrate have also been observed.

  5. One step approach towards the green synthesis of silver decorated graphene nanocomposites for the degradation of organic dyes in water

    Science.gov (United States)

    Karthik, Gopakumar; Harith, A.; Nazrin Thazleema, N.; Vishal, Shaji; Jayan Jitha, S.; Saritha, Appukuttan

    2018-02-01

    Recently the decoration of graphene with metallic nanoparticles by a one pot reduction of graphene oxide (GO) coupled with the synthesis of metallic nanoparticles has gained momentum. Graphene and GO have been proved to exhibit excellent biocompatibility and high antibacterial activity and hence a vast possibility lies in the utilization of GO as an antibacterial reinforcement in biomaterials and exploration of the antiseptic properties as well as the cytotoxicity of GO-containing composites. Moreover GO decorated with metal / metal oxide paves way towards an inevitable role in water purification. The use of graphene oxide as the nano scale substrates for the development of nanocomposites with metal oxides is a novel idea to obtain a hybrid which would exhibit both the properties of GO as a enthralling paper-shape material and the quality of single nano-sized metal particles. The heavy metal ions and pollutants are considered as a major problem in environmental contamination. Hence detection of trace level pollutant has become a hot topic in the present research scenario. Modified graphene oxide nanocomposites prepared using a green approach has the capacity of absorbing pollutant material ions in high efficiency and selectivity. The green synthesized nanocomposites were characterized using FTIR and UV spectroscopy and the consequence of pH and concentration on the preparation of the nanocomposites was evaluated. The efficiency of these nanocomposites towards degradation of organic dyes like methylene blue has been evaluated.

  6. Nanocomposites of cellulose/iron oxide: influence of synthesis conditions on their morphological behavior and thermal stability

    International Nuclear Information System (INIS)

    Ma Mingguo; Zhu Jiefang; Li Shuming; Jia Ning; Sun Runcang

    2012-01-01

    Nanocomposites of cellulose/iron oxide have been successfully prepared by hydrothermal method using cellulose solution and Fe(NO 3 ) 3 ·9H 2 O at 180 °C. The cellulose solution was obtained by the dissolution of microcrystalline cellulose in NaOH/urea aqueous solution, which is a good system to dissolve cellulose and favors the synthesis of iron oxide without needing any template or other reagents. The phases, microstructure, and morphologies of nanocomposites were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectra (EDS). The effects of the heating time, heating temperature, cellulose concentration, and ferric nitrate concentration on the morphological behavior of products were investigated. The experimental results indicated that the cellulose concentration played an important role in both the phase and shape of iron oxide in nanocomposites. Moreover, the nanocomposites synthesized by using different cellulose concentrations displayed different thermal stabilities. - Highlights: ► Nanocomposites of cellulose/iron oxide have been prepared by hydrothermal method. ► The cellulose concentration played an important role in the phase of iron oxide. ► The cellulose concentration played an important role in the shape of iron oxide. ► The samples displayed different thermal stabilities.

  7. Fabrication of Mesoporous Silica/Alumina Hybrid Membrane Film Nanocomposites using Template Sol-Gel Synthesis of Amphiphilic Triphenylene

    Science.gov (United States)

    Lintang, H. O.; Jalani, M. A.; Yuliati, L.; Salleh, M. M.

    2017-05-01

    Herein we reported that by introducing a one-dimensional (1D) substrate with a porous structure such as anodic aluminum oxide (AAO) membrane, mesoporous silica/alumina hybrid nanocomposites were successfully fabricated by using amphiphilic triphenylene (TPC10TEG) as a template in sol-gel synthesis (TPC10TEG/silicahex). For the optical study of the nanocomposites, TPC10TEG/silicahex showed absorption peak at 264 nm due to the ordered and long-range π-π stacking of the disc-like aromatic triphenylene core. Moreover, the hexagonal arrangement of TPC10TEG/silicahex was proven based on their diffraction peaks of d 100 and d 200 at 2θ = 2.52° and 5.04° and images of transmission electron microscopy (TEM), respectively. For fabrication of mesoporous silica/alumina hybrid membrane, TPC10TEG/silicahex was drop-casted onto AAO membrane for penetration into the porous structure via gravity. X-ray diffraction (XRD) analysis on the resulted hybrid nanocomposites showed that the diffraction peaks of d 100 and d 200 of TPC10TEG/silicahex were still preserved, indicating that the hexagonal arrangements of mesoporous silica were maintained even on AAO substrate. The morphology study on the hybrid nanocomposites using TEM, scanning electron microscope (SEM) and field emission scanning electron microscope (FE-SEM) showed the successful filling of most AAO channels with the TPC10TEG/silicahex nanocomposites.

  8. Synthesis and characterization of Ag2S decorated chitosan nanocomposites and chitosan nanofibers for removal of lincosamides antibiotic.

    Science.gov (United States)

    Gupta, Vinod Kumar; Fakhri, Ali; Agarwal, Shilpi; Azad, Mona

    2017-10-01

    We report the synthesis of Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids as performance adsorbents for Lincosamides such as Clindamycin antibiotic removal. Isotherms and kinetic studies were determined to understand the adsorption behavior both two adsorbent. At low adsorbent dose, removals are increased in the adsorption process, and performance is better with Ag 2 S-chitosan nanohybrids due to the special surface area increased. The average sizes and surface area of Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids were found as 50nm, 70nm and 180.18, 238.24m 2 g -1 , respectively. In particular, Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids show high maximum Clindamycin adsorption capacity (q max ) of 153.21, and 181.28mgg -1 , respectively. More strikingly, Ag 2 S-Chitosan nanocomposites and Ag 2 S-chitosan nanohybrids are also demonstrated to nearly completely remove Clindamycin from drinking water. The excellent adsorption performance along with their cost effective, convenient synthesis makes this range of adsorbents highly promising for commercial applications in drinking water and wastewater treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Synthesis of a ternary Ag/RGO/ZnO nanocomposite via microwave irradiation and its application for the degradation of Rhodamine B under visible light.

    Science.gov (United States)

    Surendran, Divya Kollikkara; Xavier, Marilyn Mary; Viswanathan, Vandana Parakkal; Mathew, Suresh

    2017-06-01

    Reduced graphene oxide supporting plasmonic photocatalyst (Ag) on ZnO has been synthesized via a facile two-step microwave synthesis using RGO/ZnO and AgNO 3 . First step involves fabrication of RGO/ZnO via microwave irradiation. The nanocomposites were characterized by X-ray diffraction analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. Ag/RGO/ZnO shows enhanced photoactivity under visible light for the degradation of Rhodamine B. Enhanced charge separation and migration have been assigned using UV-vis diffuse reflectance spectra, photoluminescence spectra, electrochemical impedance spectra, and TCSPC analysis. The improved photoactivity of Ag/RGO/ZnO can be ascribed to the prolonged lifetime of photogenerated electron-hole pairs and effective interfacial hybridization between RGO and Ag with ZnO nanoparticles. Ag nanoparticles can absorb visible light via surface plasmon resonance to enhance photocatalytic activity.

  10. The tunable plasma synthesis of Pt-reduced graphene oxide nanocomposites

    Directory of Open Access Journals (Sweden)

    Yulong Ma

    2017-06-01

    Full Text Available Herein, we have developed Pt-plasma reduced graphene oxide (Pt/P-rGO catalysts displaying high overpotentials for methanol oxidation reaction (MOR through facile and tunable plasma treatments. We provide insight into the improved performance of these catalysts by combining electrochemical measurements with microscopic and spectroscopic characterization techniques. The analysis results showed that the Pt nanoparticles (NPs were successfully deposited on P-rGO. The deposition and uniformity of Pt NPs were influenced by tuning the discharge power of the plasma. The catalytic performance towards the methanol oxidation reaction is investigated. The Pt/P-rGO NPs composites under 100 W show the best electrocatalytic activity. These results were vital to the further application of graphene-based metal nanocomposites synthesized by plasma technology.

  11. Hydrothermal Synthesis of Fe3O4 Nanoparticles and Flame Resistance Magnetic Poly styrene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Kambiz Hedayati

    2017-01-01

    Full Text Available Fe3O4 nanostructures were synthesized via a facile hydrothermal reaction. The effect of various surfactants such as cationic and anionic on the morphology of the product was investigated. Magnetic nanoparticles were added to poly styrene for preparation of magnetic nanocomposite. Nanostructures were then characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The magnetic properties of the samples were also investigated using vibrating sample magnetometer. The magnesium ferrite nanoparticles exhibit super paramagnetic behaviour at room temperature, with a saturation magnetization of 66 emu/g and a coercivity less than 5 Oe. Distribution of the magnetic nanoparticles into poly styrene matrix increases the coercivity. Nanoparticles appropriately enhanced flame retardant property of the PS matrix. Nanoparticles act as barriers which decrease thermal transport and volatilization during decomposition of the polymer.

  12. Synthesis and utilization of poly (methylmethacrylate) nanocomposites based on modified montmorillonite

    OpenAIRE

    Youssef, Ahmed M.; Malhat, F.M.; Abdel Hakim, A.A.; Dekany, Imre

    2015-01-01

    Poly (methylmethacrylate) nanocomposite was prepared via in-situ emulsion polymerization (PMMA/Mt-CTA). The modified montmorillonite (Mt-CTA) is used as hosts for the preparation of poly (methylmethacrylate) nanocomposites with basal distance 1.95 nm. Moreover, exfoliated nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The fashioned nanocomposites exhibited bett...

  13. Synthesis and magnetic properties of bulk transparent PMMA/Fe-oxide nanocomposites

    Science.gov (United States)

    Li, Shanghua; Qin, Jian; Fornara, Andrea; Toprak, Muhammet; Muhammed, Mamoun; Kim, Do Kyung

    2009-05-01

    PMMA/Fe-oxide nanocomposites are fabricated by a chemical method. Monodispersed Fe-oxide nanoparticles are well dispersed in the PMMA matrix by in situ polymerization, resulting in a bulk transparent polymeric nanocomposite. The magnetic behavior of the PMMA/Fe-oxide nanocomposites is investigated. The transparent PMMA/Fe-oxide nanocomposite has potentially interesting magneto-optic applications without compromising the advantages of a lightweight, noncorrosive polymeric material with very high transparency even for bulk samples.

  14. Synthesis and magnetic properties of bulk transparent PMMA/Fe-oxide nanocomposites

    International Nuclear Information System (INIS)

    Li Shanghua; Qin Jian; Fornara, Andrea; Toprak, Muhammet; Muhammed, Mamoun; Kim, Do Kyung

    2009-01-01

    PMMA/Fe-oxide nanocomposites are fabricated by a chemical method. Monodispersed Fe-oxide nanoparticles are well dispersed in the PMMA matrix by in situ polymerization, resulting in a bulk transparent polymeric nanocomposite. The magnetic behavior of the PMMA/Fe-oxide nanocomposites is investigated. The transparent PMMA/Fe-oxide nanocomposite has potentially interesting magneto-optic applications without compromising the advantages of a lightweight, noncorrosive polymeric material with very high transparency even for bulk samples.

  15. Synthesis and Characterization of CdS/TiO2-Montmorillonite Nanocomposite with Enhanced Visible-Light Absorption

    OpenAIRE

    Feng-shan Zhou; Dai-mei Chen; Bao-lin Cui; Wei-heng Wang

    2014-01-01

    Sodium montmorillonite (MMT) was chosen as the carrier; a serial of CdS/TiO2-MMT nanocomposites with enhanced visible-light absorption ability was prepared by hydrothermal synthesis method combination with semiconductor compound modification method. The samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy; the results showed that TiO2 and CdS nanoparticles were loaded on the surface of montmorillonite unifo...

  16. Reverse microemulsion synthesis of nickel-cobalt hexacyanoferrate/reduced graphene oxide nanocomposites for high-performance supercapacitors and sodium ion batteries

    Science.gov (United States)

    Qiu, Xiaoming; Liu, Yongchang; Wang, Luning; Fan, Li-Zhen

    2018-03-01

    Prussian blue analogues with tunable open channels are of fundamental and technological importance for energy storage systems. Herein, a novel facile synthesis of nickel-cobalt hexacyanoferrate/reduced graphene oxide (denoted as Ni-CoHCF/rGO) nanocomposite is realized by a reverse microemulsion method. The very fine Ni-CoHCF nanoparticles (10-20 nm) are homogeneously anchored on the surface of reduced graphene oxide by electrostatic adsorption and reduced graphene oxide is well-separated by Ni-CoHCF particles. Benefiting from the combined advantages of this structure, the Ni-. It CoHCF/rGO nanocomposite can be used as electrodes for both supercapacitors and sodium ion batteries exhibits excellent pseudocapacitve performance in terms of high specific capacitance of 466 F g-1 at 0.2 A g-1 and 350 F g-1 at 10 A g-1, along with high cycling stabilities. As a cathode material for sodium ion batteries, it also demonstrates a high reversible capacity of 118 mAh g-1 at 0.1 A g-1, good rate capability, and superior cycling stability. These results suggest its potential as an efficient electrode for high-performance energy storage and renewable delivery devices.

  17. Low-temperature solid-state synthesis and optical properties of ZnO/CdS nanocomposites

    International Nuclear Information System (INIS)

    Liu, Jinsong; Zhu, Kongjun; Sheng, Beibei; Li, Ziquan; Tai, Guoan; Qiu, Jinhao; Wang, Jing; Chen, Jiankang; You, Yuncheng; Gu, Qilin; Liu, Pengcheng

    2015-01-01

    Highlights: • Using a low-temperature solid-state method, ZnO/CdS nanocomposites were obtained • Grain growth kinetics of cubic CdS and hexagonal ZnO phase was described. • Sufficient grinding and heating treatment was a key for formation of composites. • Optical properties could be easily manipulated by reaction temperature and time. - Abstract: A simple low-temperature solid-state reaction in the presence of the surfactant PEG400 was developed to obtain ZnO/CdS nanocomposites. The effects of synthesis temperature and reaction time on crystal structure and optical properties of the nanocomposites were investigated by several technologies. X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) characterizations showed that the products consisted of the nanoparticles, and the grain growth kinetics of the cubic CdS and the hexagonal ZnO phase in the nanocomposites was described. The mechanism analysis suggested that sufficient grinding and heating treatment was a key to form the ZnO/CdS nanocomposites, and the surfactant PEG400 was proved not to involve the reaction and prevent the nanoparticles from aggregating to larger in whole grinding and heat-treatment process. Ultraviolet–visible (UV–vis) spectra revealed that the band gaps of the nanocomposites could be tuned by the reaction temperature and reaction time. Photoluminescence (PL) spectra showed that the changing position and the intensity of the emission peaks resulted from the rate of electron transfer and recombination probability under the different conditions

  18. One-step synthesis and properties of monolithic photoluminescent ruby colored cuprous oxide antimony oxide glass nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Som, Tirtha [Glass Science and Technology Section, Glass Division, Central Glass and Ceramic Research Institute, Council of Scientific and Industrial Research (CSIR, India), 196, Raja S.C. Mullick Road, Kolkata 700032 (India); Karmakar, Basudeb, E-mail: basudebk@cgcri.res.in [Glass Science and Technology Section, Glass Division, Central Glass and Ceramic Research Institute, Council of Scientific and Industrial Research (CSIR, India), 196, Raja S.C. Mullick Road, Kolkata 700032 (India)

    2011-04-14

    Research highlights: > Single-step synthesis of Cu{sub 2}O, Cu{sub y}Sb{sub 2-x}(O,OH){sub 6-7} (y {<=} 2, x {<=} 1) and Cu nanocrystals co-doped novel antimony oxide glass hybrid nanocomposites. > Yellow and orange colored nanocomposites shows size-controlled band gap shift of Cu{sub 2}O. > Red nanocomposite exhibits surface plasmon resonance band due to metallic Cu. > They exhibit broad deep-red photoluminescence emission under various UV excitation wavelengths. - Abstract: Cuprous oxide (Cu{sub 2}O) antimony glass (K{sub 2}O-B{sub 2}O{sub 3}-Sb{sub 2}O{sub 3}) monolithic nanocomposites having brilliant yellow to ruby red color have been synthesized by a single-step melt-quench technique involving in situ thermochemical reduction of Cu{sup 2+} (CuO) by the reducing glass matrix without using any external reducing agent. The X-ray diffraction (XRD), infrared transmission and reflection spectra, and selected area electron diffraction analysis support the reduction of Cu{sup 2+} to Cu{sup +} with the formation of Cu{sub 2}O nanoclusters along with Cu{sub y}Sb{sub 2-x}(O,OH){sub 6-7} (y {<=} 2, x {<=} 1) nanocrystalline phases while Cu{sup 0} nanoclusters are formed at very high Cu concentration. The UV-vis spectra of the yellow and orange colored nanocomposites show size-controlled band gap shift of the semiconductor (Cu{sub 2}O) nanocrystallites embedded in the glasses while the red nanocomposite exhibits surface plasmon resonance band at 529 nm due to metallic Cu. Transmission electron microscopic image advocates the formation of nanocystallites (5-42 nm). Photoluminescence emission studies show broad red emission band around 626 nm under various excitation wavelengths from 210 to 270 nm.

  19. Synthesis, characterization, and efficacy of antituberculosis isoniazid zinc aluminum-layered double hydroxide based nanocomposites

    Directory of Open Access Journals (Sweden)

    Saifullah B

    2016-07-01

    Full Text Available Bullo Saifullah,1 Mohamed Ezzat El Zowalaty,2,3 Palanisamy Arulselvan,3 Sharida Fakurazi,3,4 Thomas J Webster,5–7 Benjamin Mahler Geilich,5,6 Mohd Zobir Hussein1 1Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, (ITMA, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 2School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, South Africa; 3Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, 4Department of Human Anatomy, Faculty of Medicine and Health Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 5Department of Chemical Engineering, 6Department of Bioengineering, Northeastern University, Boston, MA, USA; 7Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: The chemotherapy for tuberculosis (TB is complicated by its long-term treatment, its frequent drug dosing, and the adverse effects of anti-TB drugs. In this study, we have developed two nanocomposites (A and B by intercalating the anti-TB drug isoniazid (INH into Zn/Al-layered double hydroxides. The average size of the nanocomposites was found to be ~164 nm. The efficacy of the Zn/Al-layered double hydroxides intercalated INH against Mycobacterium tuberculosis was increased by approximately three times more than free INH. The nanocomposites were also found to be active against Gram-positive and -negative bacteria. Compared to the free INH, the nanodelivery formulation was determined to be three times more biocompatible with human normal lung fibroblast MRC-5 cells and 3T3 fibroblast cells at a very high concentration of 50 µg/mL for up to 72 hours. The in vitro release of INH from the Zn/Al-layered double hydroxides was found to be sustained in human body-simulated buffer solutions of pH 4.8 and 7.4. This research is a step forward in making the TB chemotherapy patient friendly. Keywords: tuberculosis, Zn/Al-LDHs, drug

  20. Log-pile photonic crystal of CdS-polymer nanocomposites fabricated by combination of two-photon polymerization and in situ synthesis

    International Nuclear Information System (INIS)

    Sun, Z.-B.; Dong, X.-Z.; Chen, W.-Q.; Duan, X.-M.; Nakanishi, S.; Kawata, S.

    2007-01-01

    A log-pile photonic crystal of CdS nanoparticles-polymer nanocomposites was successfully fabricated by a novel method combining the two-photon polymerization technique and in situ synthesis of CdS nanoparticles in a polymer matrix. The photonic band gap of the three-dimensional (3D) log-pile photonic crystal is confirmed and becomes more effective for CdS nanoparticles-polymer nanocomposites than polymer doped with Cd 2+ ions, because the nanocomposites possess a higher refractive index than the polymer. The proposed concept in the new fabrication method for a 3D microstructure of polymer nanocomposites should be of critical importance in providing a general methodology for functionalization of materials via functional nanocomposites used in the field of laser microstructure fabrication. (orig.)

  1. Facile charge transport in FeN x /Mo₂N/CNT nanocomposites for ...

    Indian Academy of Sciences (India)

    The nanocomposites were characterized using powder XRD, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), ElectronDiffraction, ThermogravimetricAnalysis and FTIRSpectroscopy. The electrochemical investigations suggest that the electrocatalytic activity of the composite increases with ...

  2. Synthesis and characterization of Zinc (II)-loaded Zeolite/Graphene oxide nanocomposite as a new drug carrier

    Energy Technology Data Exchange (ETDEWEB)

    Khatamian, M. [Inorganic Chemistry Department, Faculty of Chemistry, University of Tabriz, C.P. 51664 Tabriz (Iran, Islamic Republic of); Divband, B., E-mail: baharakdivband@yahoo.com [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Inorganic Chemistry Department, Faculty of Chemistry, University of Tabriz, C.P. 51664 Tabriz (Iran, Islamic Republic of); Farahmand-zahed, F. [Inorganic Chemistry Department, Faculty of Chemistry, University of Tabriz, C.P. 51664 Tabriz (Iran, Islamic Republic of)

    2016-09-01

    Current research has focused on the preparation of Zinc-clinoptilolite/Graphene Oxide (Zn-Clin/GO) hybrid nanostructure and investigating its biocompatibility for the first time. As prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Thermo gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). In order to use it as a drug carrier two important factors were investigated: cytocompatibility of nanocomposites and their drug loading capacity. The results showed that the prepared nanocomposite is cytocompatible and its high loading capacity and slow release performance for Doxorubicin (DOX), as a cancer drug, proved that it can be used as a drug carrier. At last in-vitro toxicity of DOX loaded nanocomposite was compared with pure DOX. - Graphical abstract: Biocompatible Zn-clinoptilolite/Graphene oxide hybrid nanostructure as in vitro drug delivery systems (DDS) was able to store and release substantial amounts of doxorubicin to the lung cancer cell lines. Display Omitted - Highlights: • Zn-Clin/GO nanocomposite as a new in vitro drug carrier with high loading capacity is synthesized. • Two synthesis methods (Microwave assisted hydrothermal method and Reflux method) are used. • All of the carriers (Zn-Clin, Zn-Clin/GO, GO) showed high biocompatibility.

  3. Synthesis and characterization of Zinc (II)-loaded Zeolite/Graphene oxide nanocomposite as a new drug carrier

    International Nuclear Information System (INIS)

    Khatamian, M.; Divband, B.; Farahmand-zahed, F.

    2016-01-01

    Current research has focused on the preparation of Zinc-clinoptilolite/Graphene Oxide (Zn-Clin/GO) hybrid nanostructure and investigating its biocompatibility for the first time. As prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Thermo gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). In order to use it as a drug carrier two important factors were investigated: cytocompatibility of nanocomposites and their drug loading capacity. The results showed that the prepared nanocomposite is cytocompatible and its high loading capacity and slow release performance for Doxorubicin (DOX), as a cancer drug, proved that it can be used as a drug carrier. At last in-vitro toxicity of DOX loaded nanocomposite was compared with pure DOX. - Graphical abstract: Biocompatible Zn-clinoptilolite/Graphene oxide hybrid nanostructure as in vitro drug delivery systems (DDS) was able to store and release substantial amounts of doxorubicin to the lung cancer cell lines. Display Omitted - Highlights: • Zn-Clin/GO nanocomposite as a new in vitro drug carrier with high loading capacity is synthesized. • Two synthesis methods (Microwave assisted hydrothermal method and Reflux method) are used. • All of the carriers (Zn-Clin, Zn-Clin/GO, GO) showed high biocompatibility.

  4. Poly(o-phenylenediamine)/NiCoFe{sub 2}O{sub 4} nanocomposites: Synthesis, characterization, magnetic and dielectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Kannapiran, Nagarajan [PG and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India); Muthusamy, Athianna, E-mail: muthusrkv@gmail.com [PG and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India); Chitra, Palanisamy; Anand, Siddeswaran [PG and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India); Jayaprakash, Rajan [Nanotechnology Laboratory, Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu (India)

    2017-02-01

    In this study, poly(o-phenylenediamine) (PoPD)/NiCoFe{sub 2}O{sub 4} nanocomposites were synthesized by in-situ oxidative chemical polymerization method with different amount of NiCoFe{sub 2}O{sub 4} nanoparticles. The NiCoFe{sub 2}O{sub 4} nanoparticles were prepared by auto-combustion method. The structural, morphological, thermal properties of the synthesized PoPD/NiCoFe{sub 2}O{sub 4} nanocomposites were characterized by fourier transform infrared spectrum (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). Magnetic properties of NiCoFe{sub 2}O{sub 4} nanoparticles and PoPD/NiCoFe{sub 2}O{sub 4} nanocomposites were studied by vibrating sample magnetometer (VSM). The FTIR and XRD techniques were used to confirm the formation of PoPD/NiCoFe{sub 2}O{sub 4} nanocomposites. The average crystalline size of NiCoFe{sub 2}O{sub 4} nanoparticles and PoPD/NiCoFe{sub 2}O{sub 4} nanocomposites were calculated from XRD. From the SEM analysis, spherical morphology of the PoPD was confirmed. The TGA results showed that the NiCoFe{sub 2}O{sub 4} nanoparticles have improved the thermal stability of PoPD. Dielectric properties of PoPD/NiCoFe{sub 2}O{sub 4} nanocomposites at different temperatures have been carried in the frequency range 50 Hz to 5 MHz. - Highlights: • Auto-combustion method was support to achieve less particle size. • Green synthesis of PoPD and nanocomposites by in-situ oxidative chemical polymerization method. • For the first time, PoPD incorporated with NiCoFe{sub 2}O{sub 4} nanoparticles. • Ferrite content affects the magnetic and dielectric properties of the nanocomposites.

  5. Facilely synthesized Fe2O3–graphene nanocomposite as novel electrode materials for supercapacitors with high performance

    International Nuclear Information System (INIS)

    Wang, Zhuo; Ma, Chunyan; Wang, Hailin; Liu, Zonghuai; Hao, Zhengping

    2013-01-01

    Graphical abstract: Fe 2 O 3 Graphene nanocomposite was synthesized in a simple hydrothermal way by using urea to adjust the system pH value, by this method the reduction of graphite oxide and the formation of Fe 2 O 3 nanocomposite are finished in one step. The specific capacitance of the Fe 2 O 3 Graphene electrode reached 226 F/g at a discharge current density of 1 A g –1 . Highlights: ► The Fe 2 O 3 –graphene nanocomposite was obtained by friendly method with urea in one step. ► The addition of Fe 2 O 3 composites has positive effect on the electrical performance of the graphene nanosheets. ► The specific capacitance of the Fe 2 O 3 –graphene electrode was 226 F/g at a discharge current density of 1 A g −1 . -- Abstract: Fe 2 O 3 –graphene nanocomposite with high capacitive properties had been prepared friendly and facilely by hydrothermal method in one-step. The morphology and structure of the obtained material were examined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and transmission electron microscope (TEM) techniques. It was revealed by TEM images that Fe 2 O 3 nanoparticles grow well on the surface of graphene and the formation of Fe 2 O 3 nanoparticles hinders the aggregation of graphene (reduced graphene oxide, namely, RGO). Electrochemical properties of the synthesized materials were characterized by serials of electrochemical measurements in 1 M Na 2 SO 4 electrolyte. Fe 2 O 3 –graphene nanocomposite electrode show higher specific capacitance than graphene, indicating an accelerative effect of Fe 2 O 3 and graphene on improving the electrochemical performance of the electrode. The specific capacitance of Fe 2 O 3 –graphene nanocomposite is 226 F/g at a current density of 1 A/g. These attractive results indicate it is possible to seek and develop the promising, environmentally benign and commercial electrodes material based on Fe 2 O 3 and graphene

  6. Facile Preparation, Characterization, and Highly Effective Microwave Absorption Performance of CNTs/Fe3O4/PANI Nanocomposites

    Directory of Open Access Journals (Sweden)

    Deqing Zhang

    2013-01-01

    Full Text Available A facile method has been developed to synthesize light-weight CNTs/Fe3O4/PANI nanocomposites. The formation route was proposed as the coprecipitation of Fe2+ and Fe3+ and an additional process of in situ polymerization of aniline monomer. The structure and morphology of CNTs/Fe3O4/PANI were characterized by transmission electron microscopy (TEM, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared (FTIR spectroscopy. The TEM investigation shows that the CNTs/Fe3O4/PANI nanocomposites exhibit less intertwined structure and that many more Fe3O4 particles are attached homogeneously on the surface of CNTs, indicating that PANI can indeed help CNTs to disperse in isolated form. The wave-absorbing properties were investigated in a frequency of 2–18 GHz. The results show that the CNTs/Fe3O4/PANI nanocomposites exhibit a super absorbing behavior and possess a maximum reflection loss of −48 dB at 12.9 GHz, and the bandwidth below −20 dB is more than 5 GHz. More importantly, the absorption peak frequency ranges of the CNTs/Fe3O4/PANI composites can be tuned easily by changing the wax weight ratio and thickness of CNTs/Fe3O4/PANI paraffin wax matrix.

  7. Synthesis of Upconverting Hydrogel Nanocomposites Using Thiol-Ene Click Chemistry: Template for the Formation of Dendrimer-Like Gold Nanoparticle Assemblies.

    Science.gov (United States)

    Meesaragandla, Brahmaiah; Mahalingam, Venkataramanan

    2015-11-16

    The synthesis of upconverting hydrogel nanocomposites by base-catalyzed thiol-ene click reaction between 10-undecenoic acid capped Yb(3+)/Er(3+)-doped NaYF4 nanoparticles and pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) as tetrathiol monomer is reported. This synthetic strategy for nanocomposite gels is quite different from works where usually the preformed gels are mixed with the nanoparticles. Developing nanocomposites by surface modification of capping ligands would allow tuning and controlling of the separation of the nanoparticles inside the gel network. The hydrogel nanocomposites prepared by thiol-ene click reaction show strong enhancement in luminescence intensity compared to 10-undecenoic acid-capped Yb(3+)/Er(3+)-doped NaYF4 nanoparticles through the upconversion process (under 980 nm laser excitation). The hydrogel nanocomposites display strong swelling characteristics in water resulting in porous structures. Interestingly, the resulting nanocomposite gels act as templates for the synthesis of dendrimer-like Au nanostructures when HAuCl4 is reduced in the presence of the nanocomposite gels. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Size-controlled in situ synthesis and photo-responsive properties of silver/poly(methyl methacrylate) nanocomposite films with high silver content

    Energy Technology Data Exchange (ETDEWEB)

    Chen Cheng; Li Junguo [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Luo Guoqiang, E-mail: qhy2013@163.com [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Xiong Yuanlu; Zhang Qiang; Shen Lianmeng [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Ag/PMMA nanocomposite films with high silver content are prepared by in situ synthesis. Black-Right-Pointing-Pointer The size of Ag nanoparticles can be controlled by reaction time. Black-Right-Pointing-Pointer The electrical properties of Ag/PMMA nanocomposites films shows enhancement compared with the pure PMMA. Black-Right-Pointing-Pointer The recycle photo-responsive properties of Ag/PMMA nanocomposite films are proposed. - Abstract: Ag/PMMA nanocomposites have attracted much attention due to its superior mechanical, optical and electrical properties. In this article, Ag/PMMA nanocomposite films with high silver content (20 wt%) have been successfully in situ synthesized. UV-vis analysis, transmission electron microscopy (TEM), current-voltage (I-V) analysis, hall effect measurement system and electrochemical workstation are used to characterize the nanocomposite films. The results reveal that silver nanoparticles (NPs) homogeneously distribute in PMMA films and the particles size of silver NPs which has been controlled from 1.68 to 6.98 nm. Ag/PMMA nanocomposite films show electrical properties due to the conduction paths created by Ag nanoparticles. With the increasing diameter of silver NPs, the current density decreases and resistivity increases, respectively. Photo-responsive properties of Ag/PMMA nanocomposite films indicate that conduction paths could be destroyed by illumination and rebuilt in dark condition.

  9. Size-controlled in situ synthesis and photo-responsive properties of silver/poly(methyl methacrylate) nanocomposite films with high silver content

    International Nuclear Information System (INIS)

    Chen Cheng; Li Junguo; Luo Guoqiang; Xiong Yuanlu; Zhang Qiang; Shen Lianmeng

    2012-01-01

    Highlights: ► Ag/PMMA nanocomposite films with high silver content are prepared by in situ synthesis. ► The size of Ag nanoparticles can be controlled by reaction time. ► The electrical properties of Ag/PMMA nanocomposites films shows enhancement compared with the pure PMMA. ► The recycle photo-responsive properties of Ag/PMMA nanocomposite films are proposed. - Abstract: Ag/PMMA nanocomposites have attracted much attention due to its superior mechanical, optical and electrical properties. In this article, Ag/PMMA nanocomposite films with high silver content (20 wt%) have been successfully in situ synthesized. UV–vis analysis, transmission electron microscopy (TEM), current–voltage (I–V) analysis, hall effect measurement system and electrochemical workstation are used to characterize the nanocomposite films. The results reveal that silver nanoparticles (NPs) homogeneously distribute in PMMA films and the particles size of silver NPs which has been controlled from 1.68 to 6.98 nm. Ag/PMMA nanocomposite films show electrical properties due to the conduction paths created by Ag nanoparticles. With the increasing diameter of silver NPs, the current density decreases and resistivity increases, respectively. Photo-responsive properties of Ag/PMMA nanocomposite films indicate that conduction paths could be destroyed by illumination and rebuilt in dark condition.

  10. Synthesis of NiO–Al{sub 2}O{sub 3} nanocomposites by sol–gel process and their use as catalyst for the oxidation of styrene

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Sudheer Kumar; Jeevanandam, P., E-mail: jeevafcy@iitr.ac.in

    2014-10-15

    Highlights: • NiO–Al{sub 2}O{sub 3} nanocomposites have been synthesized by sol–gel method. • The synthesis takes shorter time (∼48 h) compared to reported methods. • The nanocomposites show high catalytic activity for the oxidation of styrene compared to NiO. - Abstract: NiO–Al{sub 2}O{sub 3} nanocomposites were prepared by sol–gel method. The synthesized nanocomposites were characterized by X-ray diffraction, FT-IR spectroscopy, Raman spectroscopy, field emission scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, diffuse reflectance spectroscopy and magnetic measurements. XRD results indicate that the NiO–Al{sub 2}O{sub 3} nanocomposites consist of small NiO crystallites (mean size ∼2.6 nm). TEM results indicate uniform distribution of NiO nanoparticles in the Al{sub 2}O{sub 3} matrix. Increase in the band gap of NiO in the nanocomposites compared to pure NiO nanoparticles is observed and the nanocomposites show superparamagnetic behaviour. The NiO–Al{sub 2}O{sub 3} nanocomposites show high catalytic activity for the oxidation of styrene using tert-butyl hydroperoxide as the oxidant and also show higher selectivity for styrene oxide with higher total conversion compared to pure NiO nanoparticles.

  11. One-step, simple, and green synthesis of tin dioxide/graphene nanocomposites and their application to lithium-ion battery anodes

    International Nuclear Information System (INIS)

    Jiang, Zaixing; Zhang, Dongjie; Li, Yue; Cheng, Hao; Wang, Mingqiang; Wang, Xueqin; Bai, Yongping; Lv, Haibao; Yao, Yongtao; Shao, Lu; Huang, Yudong

    2014-01-01

    Highlights: • A one-step, simple and green approach to synthesis SnO 2 /graphene nanocomposites was proposed using a supercritical CO 2 method. • The SnO 2 /graphene nanocomposites was used as an anode, which exhibit extreme high lithium storage capacity and well cycling performance. - Abstract: Graphene with extraordinary thermal, mechanical and electrical properties offers possibilities in a variety of applications. Recent advances in the synthesis of graphene composites using supercritical fluids are highlighted. Supercritical fluids exhibit unique features for the synthesis of composites due to its low viscosity, high diffusivity, near-zero surface tension, and tunability. Here, we report the preparation of tin dioxide (SnO 2 )/graphene nanocomposite through supercritical CO 2 method. It demonstrates that the SnO 2 nanoparticles are homogeneously dispersed on the surface of graphene sheets with a particle size of 2.3–2.6 nm. The SnO 2 /graphene nanocomposites exhibit higher lithium storage capacity and better cycling performance compared to that of the similar CNT nanocomposites. The reported synthetic procedure is straightforward, green and inexpensive. And it may be readily adopted to produce large quantities of graphene based nanocomposites

  12. Synthesis and biological evaluation of PMMA/MMT nanocomposite as denture base material.

    Science.gov (United States)

    Zheng, Junping; Su, Qiang; Wang, Chen; Cheng, Gang; Zhu, Ran; Shi, Jin; Yao, Kangde

    2011-04-01

    Inorganic-polymer nanocomposites are of significant interest for emerging materials due to their improved properties and unique combination of properties. Poly (methylmethacrylate) (PMMA)/montmorillonite (MMT) nanocomposites were prepared by in situ suspension polymerization with dodecylamine used as MMT-modifier. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the structures of the nanocomposites. Cytotoxicity test, hemolysis test, acute systemic toxicity test, oral mucous membrane irritation test, guinea-pig maximization test and mouse bone-marrow micronucleus test were used to evaluate the biocompatibility of PMMA/MMT nanocomposites. The results indicated that an exfoliated nanocomposite was achieved, and the resulting nanocomposites exhibited excellent biocompatibility as denture base material and had potential application in dental materials.

  13. Aromatic-aliphatic polyamide/montmorillonite clay nanocomposite materials: Synthesis, nanostructure and properties

    International Nuclear Information System (INIS)

    Zulfiqar, Sonia; Ahmad, Zahoor; Ishaq, Muhammad; Sarwar, Muhammad Ilyas

    2009-01-01

    New type of aromatic-aliphatic polyamide/montmorillonite nanocomposites were produced using solution intercalation technique in dimethylacetamide. The modification of clay was carried out with ammonium salt of long chain alkyl amine. The nanocomposites were probed for organoclay dispersion, mechanical, thermal and water absorption measurements. Formation of delaminated and intercalated nanostructures was confirmed by X-ray diffraction and TEM studies. Improvement in tensile strength and modulus was observed for nanocomposites with optimum organoclay content (8-wt.%). Thermogravimetric analysis indicated an increase in thermal stability of nanocomposites as compared to pristine polyamide. Differential scanning calorimetric results revealed increase in glass transition temperatures (T g ) with augmenting organoclay in the nanocomposites. Water uptake of the nanocomposites reduced than the neat polyamide rendering decreased permeability.

  14. Aromatic-aliphatic polyamide/montmorillonite clay nanocomposite materials: Synthesis, nanostructure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Zulfiqar, Sonia [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Ahmad, Zahoor [Department of Chemistry, Faculty of Science, Kuwait University, P. O. Box: 5969, Safat 13060 (Kuwait); Ishaq, Muhammad [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Sarwar, Muhammad Ilyas, E-mail: ilyassarwar@hotmail.com [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716 (United States)

    2009-11-15

    New type of aromatic-aliphatic polyamide/montmorillonite nanocomposites were produced using solution intercalation technique in dimethylacetamide. The modification of clay was carried out with ammonium salt of long chain alkyl amine. The nanocomposites were probed for organoclay dispersion, mechanical, thermal and water absorption measurements. Formation of delaminated and intercalated nanostructures was confirmed by X-ray diffraction and TEM studies. Improvement in tensile strength and modulus was observed for nanocomposites with optimum organoclay content (8-wt.%). Thermogravimetric analysis indicated an increase in thermal stability of nanocomposites as compared to pristine polyamide. Differential scanning calorimetric results revealed increase in glass transition temperatures (T{sub g}) with augmenting organoclay in the nanocomposites. Water uptake of the nanocomposites reduced than the neat polyamide rendering decreased permeability.

  15. Facile synthesis of SnO2 nanocrystals anchored onto graphene nanosheets as anode materials for lithium-ion batteries.

    Science.gov (United States)

    Zhang, Yanjun; Jiang, Li; Wang, Chunru

    2015-08-21

    A SnO2/graphene nanocomposite was prepared via a facile solvothermal process using stannous octoate as a Sn source. The as-prepared SnO2/graphene nanocomposite exhibited excellent electrochemical behavior with a high reversible capacity, a long cycle life and a good rate capability when used as an anode material for lithium-ion batteries.

  16. Synthesis of thermoplastic starch-bacterial cellulose nanocomposites via in situ fermentation

    OpenAIRE

    Osorio, Marlon A.; Restrepo, David; Velásquez-Cock, Jorge A.; Zuluaga, Robin O.; Montoya, Ursula; Rojas, Orlando; Gañán, Piedad F.; Marin, Diana; Castro, Cristina I.

    2014-01-01

    In this paper, a nanocomposite based on thermoplastic starch (TPS) reinforced with bacterial cellulose (BC) nanoribbons was synthesized by in situ fermentation and chemical crosslinking. BC nanoribbons were produced by a Colombian native strain of Gluconacetobacter medellinensis; the nanocomposite was plasticized with glycerol and crosslinked with citric acid. The reinforcement percentage in the nanocomposites remained constant throughout the fermentation time because of the TPS absorption ca...

  17. Ultrafine Magnetite Nanopowder: Synthesis, Characterization, and Preliminary Use as Filler of Polymethylmethacrylate Nanocomposites

    Directory of Open Access Journals (Sweden)

    Pietro Russo

    2012-01-01

    Full Text Available Magnetite (Fe3O4 nanoparticles prepared by microwave-assisted hydrothermal synthesis have been characterized in terms of morphological and structural features. Electron micrographs collected in both scanning (SEM and transmission (TEM modes and evaluations of X-ray powder diffraction (XRD patterns have indicated the achievement of a monodispersed crystallite structure with particles having an average size around 15–20 nm. Structural investigations by Micro-Raman spectroscopy highlighted the obtainment of magnetite nanocrystals with a partial surface oxidation to maghemite (γ-Fe3O4. Preliminary attention has been also paid to the use of these magnetite nanoparticles as filler for a commercial polymethylmethacrylate resin. Hybrid formulations containing up to 3 wt% of nanoparticles were prepared by melt blending and characterized by calorimetric and thermogravimetric tests. For sake of comparison, same formulations containing commercial Fe3O4 nanoparticles are also reported. Calorimetric characterization indicates an increase of both glass transition temperature and thermal stability of the nanocomposite systems when loaded with the synthesized magnetite nanoparticles rather then loaded with the same amount of commercial Fe3O4. This first observation represents just one aspect of the promising potentiality offered by the novel magnetic nanoparticles when mixed with PMMA.

  18. Synthesis and characterization of polyaniline–Fe@C magnetic nanocomposite powder

    Energy Technology Data Exchange (ETDEWEB)

    Fleaca, C.T., E-mail: claudiufleaca@yahoo.com [National Institute for Lasers, Plasma and Radiation Physics (NILPRP), Atomistilor 409, R-077125 Magurele (Romania); “Politehnica” University of Bucharest, Faculty of Applied Sciences, Physics Department, Independentei 313, Bucharest (Romania); Dumitrache, F. [National Institute for Lasers, Plasma and Radiation Physics (NILPRP), Atomistilor 409, R-077125 Magurele (Romania); “Politehnica” University of Bucharest, Faculty of Applied Sciences, Physics Department, Independentei 313, Bucharest (Romania); Morjan, I.; Niculescu, A.-M.; Sandu, I. [National Institute for Lasers, Plasma and Radiation Physics (NILPRP), Atomistilor 409, R-077125 Magurele (Romania); Ilie, A. [National Institute for Lasers, Plasma and Radiation Physics (NILPRP), Atomistilor 409, R-077125 Magurele (Romania); University of Bucharest, Physics Faculty, Atomistilor 405, Magurele (Romania); Stamatin, I.; Iordache, A. [3NanoSAE Research Center, University of Bucharest, Atomistilor 405, Magurele (Romania); Vasile, E. [“Politehnica” University of Bucharest, Faculty of Applied Chemistry and Materials Science, Gh. Polizu. 1-7, Bucharest (Romania); Prodan, G. [“Ovidius” University, Nanotechnology and Alternative Energy Sources Institute, Mamaia 124, Constanta (Romania)

    2016-06-30

    Highlights: • Carbon-encapsulated Fe–Fe{sub x}C nanoparticles were synthesized by laser pyrolysis. • Fe–C@PANI was obtained by redox polymerization in aqueous acid suspension. • The composite show low coercivity and 6 emu/g saturation magnetization. • Electric and redox behavior of Fe–C@PANI is similar with those of pure PANI. - Abstract: We report the synthesis of novel magnetic nanocomposite based on polyaniline (PANI) matrix and Fe–C nanoparticles. These hydrophobic Fe–Fe{sub x}C@C nanoparticles (having diameters under 20 nm) were synthesized by laser pyrolysis from Fe(CO){sub 5} and C{sub 2}H{sub 4}/H{sub 2} and dispersed in water using sodium carboxymethylcellulose, followed by the PANI coating using ultrasonication-assisted oxidative polymerization of aniline hydrochloride. The structure of the resulted composite was characterized by Transmission Electron Microscopy, X-ray diffraction and also by Raman and Infrared spectroscopy. The composite powder shows ferromagnetic behavior with low coercivity and 6.4 emu/g saturation magnetization, having also electric and electrochemical behavior similar with pure PANI reference.

  19. Synthesis and characterization of kaolin assisted metal nanocomposite and its tremendous adsorptive and photo catalytic applications

    International Nuclear Information System (INIS)

    Tahir, H.; Saad, M.; Saleem, U.

    2018-01-01

    The present work demonstrates the synthesis of Kaolin assisted Ag nanocomposite (Ag-KNC) by co-precipitation method. The surface morphology of them was studied through SEM and chemical constituents by EDS techniques. The removal of efficaciousness of Ag-KNC was tested by Malachite Green Oxalate (MGO) dye through batch adsorption and photocatalytic strategies. The sorption experiments were preceded under the optimized conditions like amount of adsorbent, stay time and pH. The feasibility of the process was determined by employing Freundlich, Langmuir and D-R (Dubinin –Radushkevich) adsorption isotherms. The pH at point of zero charge (pHpzc) was conjointly calculable to work out the surface neutrality of the system. The salt effect for the removal of MGO dye was investigated. Thermodynamic parameters like free energy (∆Go), entropy (∆So) and enthalpy (∆Ho), of the system was investigated. Adsorption Kinetic was resolute by Intra particle diffusion (IPD) and Boyd’s models. An attempt was made to prepare (Ag-KCN) nanophoto catalyst by UV light assisted degradation of Malachite Green Oxalate (MGO) dye. They were prepared by the reduction of Ag+ ion under alkaline conditions on kaolin surface. The photo degradation (PD) process was initiated by photo generated electrons. The present study recommended that projected strategies were successfully applied for the remediation of environmental problems. (author)

  20. Synthesis and characterization of gold nanoparticles in a self-assembled ionic liquid polymer nanocomposite

    Science.gov (United States)

    Magurudeniya, Harsha; Ringstrand, Bryan; Jungjohann, Katherine; Firestone, Millicent

    Incorporation of nanoparticles(NPs) into polymer matrices has attracted interest, offering a means to create multi-functional materials combining the attributes of polymers (flexibility, processability, mechanical durability) with the opto-electrical properties of NPs. Synthesis of a self-supporting, hierarchically structured Au NP-network polymer was accomplished via a ``one-pot'' reaction employing a mesophase of AuCl3 and an imidazolium based-ionic liquid (IL) containing a acrylate group. In-situ generation of NPs was achieved by reduction of Au3+which in turn yields concomitant initiation of the polymerization of the mesophase. FT-IR and thermal analysis confirmed acrylate cross-linking. X-ray scattering confirms preservation of the mesophase within the NP composite. TEM showed a distribution of the NPs within the composite of primarily non-spherical morphologies. The co-integration of a macromer, PEG diacrylate, served as a reducing agent for the Au and the amount incorporated into the mesophase allowed for manipulation of the swelling factor of the resultant nanocomposite in a ethanol, providing means to modulate the plasmonic resonance of the NPs. This methodology provides means for organizing NPs within the structured regions of the poly(IL) matrix. Such composites may be of interest for photonic/sensing applications.

  1. Synthesis and magnetic property of T4 virus-supported gold-coated iron ternary nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Xu Ziming; Sun Hongjing; Gao Faming, E-mail: fmgao@ysu.edu.cn; Hou Li; Li Na [Yanshan University, Key Laboratory of Applied Chemistry (China)

    2012-12-15

    Herein, we present a novel method based on the use of the symmetrical T4 bacteriophage capsid as a scaffold for preparing the gold-coated iron ternary core/shell nanostructure. Results showed that the thick gold shell was obtained to effectively protect Fe core from oxidation. Magnetic measurements showed that the nanocomposites were superparamagnetic at room temperature with a blocking temperature of about 35 K. At 3 K, its coercivity of 1142.86 Oe was larger than the existing experimental values. The magnetic property of Au/T4 was also tested, demonstrating the source of the magnetic sample arising from the Fe core only. The absorption spectrum of the Fe-Au/T4 complex was measured and compared with gold/virus. Different thickness gold shells were controlled in the synthesis by tuning the Au salt addition. On the basis of results and discussion, we further speculated the general growing mechanism of the template-supported Fe-Au process.

  2. Synthesis and magnetic property of T4 virus-supported gold-coated iron ternary nanocomposite

    Science.gov (United States)

    Xu, Ziming; Sun, Hongjing; Gao, Faming; Hou, Li; Li, Na

    2012-12-01

    Herein, we present a novel method based on the use of the symmetrical T4 bacteriophage capsid as a scaffold for preparing the gold-coated iron ternary core/shell nanostructure. Results showed that the thick gold shell was obtained to effectively protect Fe core from oxidation. Magnetic measurements showed that the nanocomposites were superparamagnetic at room temperature with a blocking temperature of about 35 K. At 3 K, its coercivity of 1142.86 Oe was larger than the existing experimental values. The magnetic property of Au/T4 was also tested, demonstrating the source of the magnetic sample arising from the Fe core only. The absorption spectrum of the Fe@Au/T4 complex was measured and compared with gold/virus. Different thickness gold shells were controlled in the synthesis by tuning the Au salt addition. On the basis of results and discussion, we further speculated the general growing mechanism of the template-supported Fe@Au process.

  3. Trimetallic oxide nanocomposites of transition metals titanium and vanadium by sol-gel technique: synthesis, characterization and electronic properties

    Science.gov (United States)

    Kumar, Amit; Mishra, Neeraj Kumar; Sachan, Komal; Ali, Md Asif; Soaham Gupta, Sachchidanand; Singh, Rajeev

    2018-04-01

    Novel titanium and vanadium based trimetallic oxide nanocomposites (TMONCs) have been synthesized using metal salts of titanium-vanadium along with three others metals viz. tin, aluminium and zinc as precursors by the sol-gel method. Aqueous ammonia and hydrazine hydrate were used as the reducing agents. The preparations of nanocomposites were monitored by observing the visual changes during each step of synthesis. The synthesized TMONCs were characterized using UV–vis, SEM, EDX, TEM and DLS. Band gap of the synthesized TMONCs ranges from 3–4.5 eV determined using tauc plot. FTIR study revealed the molecular stretching and bending peaks of corresponding M–O/M–O–M bonds thus confirming their formation. Molecular composition and particle size were determined using EDX and DLS respectively. Molecular shape, size and surface morphology have been examined by SEM and TEM.

  4. Synthesis and characterization of nanocomposites based on polyurethane in aqueous dispersions with non-modified hydrophilic clays

    International Nuclear Information System (INIS)

    Miranda, G.S.; Delpechi, M.C.; Santo, W.L.E.

    2010-01-01

    Several studies involving the formation of polyurethane nanocomposites employing clays of montmorillonite modified. This involves the presence of quaternary ammonium salts, the cation exchange needed to increase the interlayer space of clays that incorporate more than one step to the process, generates a higher cost. In this paper the synthesis of nanocomposite polyurethanes dispersed in water allowed not only the production of materials less harmful to the environment, but also the incorporation of hydrophilic clays, calcium and sodium in nature, without any modifications. Dispersions produced from 0.5, 1.0 and 2.5% clay (on the mass of prepolymer) were characterized in terms of total solids content, the films obtained by casting were evaluated for adhesiveness, diffraction X-rays, scanning electron microscopy. Most systems showed intercalated and partially exfoliated structures. (author)

  5. Controlled synthesis of MnSn(OH)6/graphene nanocomposites and their electrochemical properties as capacitive materials

    International Nuclear Information System (INIS)

    Wang Gongkai; Sun Xiang; Lu Fengyuan; Yu Qingkai; Liu Changsheng; Lian Jie

    2012-01-01

    We report the synthesis of novel MnSn(OH) 6 /graphene nanocomposites produced by a co-precipitation method and their potential application for electrochemical energy storage. The hydroxide decorated graphene nanocomposites display better performance over pure MnSn(OH) 6 nanoparticles because the graphene sheets act as conductive bridges improving the ionic and electronic transport. The crystallinity of MnSn(OH) 6 nanoparticles deposited on the surface of graphene sheets also impacts the capacitive properties as electrodes. The maximum capacitance of 31.2 F/g (59.4 F/g based on the mass of MnSn(OH) 6 nanoparticles) was achieved for the sample with a low degree of crystallinity. No significant degradation of capacitance occurred after 500 cycles at a current density of 1.5 A/g in 1 M Na 2 SO 4 aqueous solution, indicating an excellent electrochemical stability. The results serve as an example demonstrating the potential of integrating highly conductive graphene networks into binary metal hydroxide in improving the performance of active electrode materials for electrochemical energy storage applications. - Graphical abstract: Graphite oxide (GO) can be synthesized by oxidizing graphite using Hummers method. Graphene was reduced from GO by thermal exfoliation. In this work, MnSn(OH) 6 /graphene nano-composites were synthesized by a simple co-precipitation method and their electrochemical performances have been explored. Highlights: ► Noval MnSn(OH) 6 /graphene nano-composites were synthesized. ► Microstructure can be tailored by changing the reaction temperature and time. ► Crystallinity of MnSn(OH) 6 nanoparticles impacts capacitive properties as electrode. ► Nano-composites display improved electrochemical performance over MnSn(OH) 6 alone. ► Results serve as an example demonstrating the potential for energy storage.

  6. Synthesis of Carbon–Metal Multi-Strand Nanocomposites by Discharges in Heptane Between Two Metallic Electrodes

    KAUST Repository

    Hamdan, Ahmad

    2017-04-26

    We studied composite wires assembled from electric field-driven nanoparticles in a dielectric liquid (heptane) to elucidate the exact processes and controlling factors involved in the synthesis of the multi-phase nanocomposites. Filamentary wires are synthesized by a two-step process: (1) abundant nanoparticle production, mostly of carbonaceous types, from heptane decomposition by spark discharge and of metal nanoparticles by electrode erosion and (2) assembly of hydrogenated amorphous carbonaceous nano-clusters with incorporated metal nanoparticles forming wires by dielectrophoretic transport while maintaining a high electric field between electrodes kept sufficiently separated to avoid breakdown. Four types of nanocomposites products are identified to form at different steps in distinctive zones of the setup. The black carbonaceous agglomerates with metal spherules made by electrode erosion represent the pyrolytic residues of heptane decomposition by spark discharge during step 1. The filamentary wires grown in the interelectrode gap during step 2 get assembled by dielectrophoretic transport and chaining forces. Their great stability is shown to express the concurrent effect of polymerization favoured by the abundance of metal catalysts. The nature, abundance, and transformation of solid particles from the source materials versus discharge conditions control the morphological and compositional diversity of the wires. The production of mineral and metal nano-particles traces the efficiency of dielectrophoresis to separate compound particle mixtures by size and to co-synthesize nanostructured microcrystals and nanocomposites. The link between impurities and the variability from nano- to micro-scales of the synthesized products provides an innovative contribution to the knowledge of nanocomposite synthesis triggered by electric field.

  7. Facile hydrothermal preparation of titanium dioxide decorated reduced graphene oxide nanocomposite

    Science.gov (United States)

    Chang, Betty Yea Sze; Huang, Nay Ming; An’amt, Mohd Nor; Marlinda, Abdul Rahman; Norazriena, Yusoff; Muhamad, Muhamad Rasat; Harrison, Ian; Lim, Hong Ngee; Chia, Chin Hua

    2012-01-01

    A simple single-stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide/titanium dioxide nanocomposites. The titanium dioxide nanoparticles are formed at the same time as the graphene oxide is reduced to graphene. The triethanolamine used in the process has two roles. It acts as a reducing agent for the graphene oxide as well as a capping agent, allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (~20 nm). Transmission electron micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide nanosheet. Thermogravimetric analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential applications for this technology were demonstrated by the use of a reduced graphene oxide/titanium dioxide nanocomposite-modified glassy carbon electrode, which enhanced the electrochemical performance compared to a conventional glassy carbon electrode when interacting with mercury(II) ions in potassium chloride electrolyte. PMID:22848166

  8. clay nanocomposites

    Indian Academy of Sciences (India)

    The present work deals with the synthesis of specialty elastomer [fluoroelastomer and poly (styrene--ethylene-co-butylene--styrene (SEBS)]–clay nanocomposites and their structure–property relationship as elucidated from morphology studies by atomic force microscopy, transmission electron microscopy and X-ray ...

  9. One-step synthesis of soy protein/graphene nanocomposites and their application in photothermal therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xuejiao; Li, Zhao; Yao, Jinrong; Shao, Zhengzhong; Chen, Xin, E-mail: chenx@fudan.edu.cn

    2016-11-01

    Photothermal therapy, due to its security and effectiveness, has recently become a promising cancer treatment after surgery, radiotherapy, chemotherapy, and biological therapy. In this article, soy protein isolate/reduced graphene oxide (SPI/rGO) nanocomposites are prepared via a simple and green process. That is, GO is reduced in situ and stabilized by SPI, an abundant, low-cost, sustainable natural material, and simultaneously forms SPI/rGO nanocomposites. The resulting SPI/rGO nanocomposites disperse in water very well and exhibit good biocompatibility due to the attachment of SPI to the surface of rGO. Such SPI/rGO nanocomposites demonstrate an excellent photothermal capacity and are able to kill HeLa cells efficiently with near-infrared irradiation (808 nm). The results in this work suggest that such a SPI/rGO hybrid material could be a promising candidate for future applications of photothermal therapy. - Highlights: • Soy protein/graphene nanocomposites are prepared via a simple and green process. • Soy protein is used as both the reducing and the stabilizing agent to graphene oxide. • Soy protein/graphene nanocomposites disperse in water well and exhibit good biocompatibility. • The nanocomposites demonstrate excellent photothermal capacity and kill HeLa cells efficiently. • Such nanocomposites can be a promising candidate for photothermal therapy in future application.

  10. Investigation on the effects of milling atmosphere on synthesis of barium ferrite/magnetite nanocomposite

    NARCIS (Netherlands)

    Molaei, M.J.; Ataie, A.; Raygan, S.; Picken, S.J.

    2011-01-01

    In this research, barium ferrite /magnetite nanocomposites synthesized via a mechano-chemical route. Graphite was used in order to reduce hematite content of barium ferrite to magnetite to produce a magnetic nanocomposite. The effects of processing conditions on the powder characteristics were

  11. Facile high-yield synthesis of polyaniline nanosticks with intrinsic stability and electrical conductivity.

    Science.gov (United States)

    Li, Xin-Gui; Li, Ang; Huang, Mei-Rong

    2008-01-01

    Chemical oxidative polymerization at 15 degrees C was used for the simple and productive synthesis of polyaniline (PAN) nanosticks. The effect of polymerization media on the yield, size, stability, and electrical conductivity of the PAN nanosticks was studied by changing the concentration and nature of the acid medium and oxidant and by introducing organic solvent. Molecular and supramolecular structure, size, and size distribution of the PAN nanosticks were characterized by UV/Vis and IR spectroscopy, X-ray diffraction, laser particle-size analysis, and transmission electron microscopy. Introduction of organic solvent is advantageous for enhancing the yield of PAN nanosticks but disadvantageous for formation of PAN nanosticks with small size and high conductivity. The concentration and nature of the acid medium have a major influence on the polymerization yield and conductivity of the nanosized PAN. The average diameter and length of PAN nanosticks produced with 2 M HNO(3) and 0.5 M H(2)SO(4) as acid media are about 40 and 300 nm, respectively. The PAN nanosticks obtained in an optimal medium (i.e., 2 M HNO(3)) exhibit the highest conductivity of 2.23 S cm(-1) and the highest yield of 80.7 %. A mechanism of formation of nanosticks instead of nanoparticles is proposed. Nanocomposite films of the PAN nanosticks with poly(vinyl alcohol) show a low percolation threshold of 0.2 wt %, at which the film retains almost the same transparency and strength as pure poly(vinyl alcohol) but 262 000 times the conductivity of pure poly(vinyl alcohol) film. The present synthesis of PAN nanosticks requires no external stabilizer and provides a facile and direct route for fabrication of PAN nanosticks with high yield, controllable size, intrinsic self-stability, strong redispersibility, high purity, and optimizable conductivity.

  12. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    Science.gov (United States)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting; Sun, Kaikai; Hu, Xili; Wang, Yujiao; Xu, Xiaoqi

    2014-10-01

    Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  13. Facile preparation of multifunctional carbon nanotube/magnetite/polyaniline nanocomposite offering a strong option for efficient solid-phase microextraction coupled with GC-MS for the analysis of phenolic compounds.

    Science.gov (United States)

    Tafazoli, Zahra; Azar, Parviz Aberoomand; Tehrani, Mohammad Saber; Husain, Syed Waqif

    2018-04-20

    The aim of this study the synthesis of a highly efficient organic-inorganic nanocomposite. In this research, the carbon nanotube/magnetite/polyaniline nanocomposite was successfully prepared through a facile route. Monodisperse magnetite nanospheres were prepared through the coprecipitation route, and polyaniline nanolayer as a modified shell with a high surface area was synthesized by an in situ growth route and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy. The prepared nanocomposite was immobilized on a stainless-steel wire for the fabrication of the solid-phase microextraction fiber. The combination of headspace solid-phase microextraction using carbon nanotube/magnetite/polyaniline nanocomposite fiber with gas chromatography and mass spectrometry can achieve a low limit of detection and can be applied to determine phenolic compounds in water samples. The effects of the extraction and desorption parameters including extraction temperature and time, ionic strength, stirring rate, pH, and desorption temperature and time have been studied. Under the optimum conditions, the dynamic linear range was 0.01-500 ng mL -1 and the limits of detection of phenol, 4-chlorophenol, 2,6-dichlorophenol, and 2,4,6-trichlorophenol were the lowest (0.008 ng mL -1 ) for three times. The coefficient of determination of all calibration curves was more than 0.990. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  14. Microwave-Assisted Synthesis of CuFe2O4 Nanoparticles and Starch-Based Magnetic Nanocomposites

    Directory of Open Access Journals (Sweden)

    Gh. Nabiyouni

    2013-06-01

    Full Text Available Magnetic CuFe2O4 nanoparticles were synthesized by a facile microwave-assisted reaction between Cu(NO32 and Fe(NO33. The magnetic nanoparticles were added to starch to make magnetic polymeric nanocomposite. The nanoparticles and nanocomposites were characterized using X-ray diffraction and scanning electron microscopy. The magnetic properties of the samples were investigated using an alternating gradient force magnetometer (AGFM. The copper ferrite nanoparticles exhibited ferromagnetic behavior at room temperature, with a saturation magnetization of 29emu/g and a coercivity of 136 Oe. The distribution of the CuFe2O4 nanoparticles into the polymeric matrixes decreases the coercivity (136 Oe to 66 Oe. The maximum coercivity of 82 Oe was found for 15% of CuFe2O4 distributed to the starch matrix.

  15. Polypyrrole–titanium(IV) doped iron(III) oxide nanocomposites: Synthesis, characterization with tunable electrical and electrochemical properties

    International Nuclear Information System (INIS)

    Nandi, Debabrata; Ghosh, Arup Kumar; Gupta, Kaushik; De, Amitabha; Sen, Pintu; Duttachowdhury, Ankan; Ghosh, Uday Chand

    2012-01-01

    Highlights: ► Synthesis and characterization of polymer nanocomposite based on titanium doped iron(III) oxide. ► Electrical conductivity increased 100 times in composite with respect to polymer. ► Electrochemical capacitance of polymer composites increased with nanooxide content. ► Thermal stability of the polymer enhanced with nano oxide content. -- Abstract: Titanium(IV)-doped synthetic nanostructured iron(III) oxide (NITO) and polypyrrole (PPy) nanocomposites was fabricated by in situ polymerization using FeCl 3 as initiator. The polymer nanocomposites (PNCs) and pure NITO were characterized by X-ray diffraction, Föurier transform infrared spectroscopy, scanning electron microscopy, electron dispersive X-ray spectroscopy, transmission electron microscopy, etc. Thermo gravimetric and differential thermal analyses showed the enhancement of thermal stability of PNCs than the pure polymer. Electrical conductivity of the PNCs had increased significantly from 0.793 × 10 −2 S/cm to 0.450 S/cm with respect to the PPy, and that had been explained by 3-dimensional variable range hopping (VRH) conduction mechanisms. In addition, the specific capacitance of PNCs had increased from 147 F/g to 176 F/g with increasing NITO content than that of pure NITO (26 F/g), presumably due to the growing of mesoporous structure with increasing NITO content in PNCs which reduced the charge transfer resistance significantly.

  16. Green synthesis of antimicrobial and antitumor N,N,N-trimethyl chitosan chloride/poly (acrylic acid)/silver nanocomposites.

    Science.gov (United States)

    Abu Elella, Mahmoud H; Mohamed, Riham R; Abdel-Aziz, Marwa M; Sabaa, Magdy W

    2018-05-01

    The present study is imported to solve two critical problems we face in our daily life which are microbial pollution and colon cancer. One pot green synthesis of a water soluble polyelectrolyte complex (PEC) between cationic polysaccharide as N,N,N-trimethyl chitosan chloride (TMC) and anionic polymer as poly (acrylic acid) (PAA) in presence of silver nanoparticles to yield (TMC/PAA/Ag) nanocomposites with different Ag weight ratios. Structure of TMC, PAA and TMC/PAA (PEC) were proved via different analysis tools. TMC/PAA and its Ag nanocomposites are used as antimicrobial agents against different pathogenic bacteria and fungi to solve microbial pollution. TMC/PAA-Silver nanocomposites had the highest antimicrobial activity which increases with increasing Ag %. Cytotoxicity data confirmed also that TMC/PAA/Ag (3%) had the most cytotoxic effect (the less cell viability %) towards colon cancer. TMC/PAA (PEC) was formed through electrostatic interactions between N-quaternized (-N + R 3 ) groups in TMC and carboxylate (-COO - ) groups in PAA. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Synthesis and characterization of protocatechuic acid-loaded gadolinium-layered double hydroxide and gold nanocomposite for theranostic application

    Science.gov (United States)

    Usman, Muhammad Sani; Hussein, Mohd Zobir; Kura, Aminu Umar; Fakurazi, Sharida; Masarudin, Mas Jaffri; Saad, Fathinul Fikri Ahmad

    2018-03-01

    A theranostic nanocomposite was developed using anticancer agent, protocatechuic acid (PA) and magnetic resonance imaging (MRI) contrast agent gadolinium nitrate (Gd) for simultaneous delivery using layered double hydroxide (LDH) as the delivery agent. Gold nanoparticles (AuNPs) were adsorbed on the surface of the LDH, which served as a complementary contrast agent. Based on the concept of supramolecular chemistry (SPC) and multimodal delivery system (MDS), the PA and Gd guests were first intercalated into the LDH host and subsequently AuNPs were surface adsorbed as the third guest. The nanohybrid developed was named MAPGAu. The MAPGAu was exposed to various characterizations at different stages of synthesis, starting with XRD analysis, which was used to confirm the intercalation episode and surface adsorption of the guest molecules. Consequently, FESEM, Hi-TEM, XRD, ICP-OES, CHNS, FTIR and UV-Vis analyses were done on the nanohybrids. The result of XRD analysis indicated successful intercalation of the Gd and PA as well the adsorption of AuNPs. The UV-Vis release study showed 90% of the intercalated drug was released at pH 4.8, which is the pH of the cancer cells. The FESEM and TEM micrographs obtained equally confirmed the formation of MAGPAu nanocomposite, with AuNPs conspicuously deposited on the LDH surface. The cytotoxicity study of the nanohybrid also showed insignificant toxicity to normal cell lines and significant toxicity to cancer cell lines. The developed MAGPAu nanocomposite has shown prospects for future theranostic cancer treatment.

  18. In-situ synthesis of Co_3O_4/graphite nanocomposite for high-performance supercapacitor electrode applications

    International Nuclear Information System (INIS)

    M, Gopalakrishnan; G, Srikesh; A, Mohan; V, Arivazhagan

    2017-01-01

    Highlights: • High surface area, which governs the specific capacitance. • High chemical and thermal stability. • Co_3O_4/graphite nanocomposite electrode shows lower resistance. - Abstract: In this work, a low cost and pollution free in-situ synthesis of phase pure Co_3O_4 nanoparticles and Co_3O_4/graphite nanocomposite have been successfully developed via co-precipitation method followed by the thermal treatment process. The prepared samples were characterized by powder X-ray diffraction, scanning electron microscope, high resolution transmission electron microscope, Fourier Transform Infrared Spectroscopy and electrochemical measurements. Electrochemical measurements such as cyclic voltammetry, galvanostatic charge–discharge, electrochemical impedance spectroscopy were carried out in 6 M KOH aqueous electrolytic solution. The results show the excellent maximum specific capacitive behavior of 239.5 F g"−"1 for pure and 395.04 F g"−"1 for Co_3O_4/graphite nanocomposite at a current density of 0.5 A g"−"1. This composite exhibits a good cyclic stability, with a small loss of 2.68% of maximum capacitance over a consecutive 1000 cycles. The investigation indicates that the prepared electrode material could be a potential and promising candidate for electrochemical supercapacitors.

  19. The microwave-assisted ionic liquid nanocomposite synthesis: platinum nanoparticles on graphene and the application on hydrogenation of styrene

    Science.gov (United States)

    2013-01-01

    The microwave-assisted nanocomposite synthesis of metal nanoparticles on graphene or graphite oxide was introduced in this research. With microwave assistance, the Pt nanoparticles on graphene/graphite oxide were successfully produced in the ionic liquid of 2-hydroxyethanaminium formate [HOCH2CH2NH3][HCO2]. On graphene/graphite oxide, the sizes of Pt nanoparticles were about 5 to 30 nm from transmitted electron microscopy (TEM) results. The crystalline Pt structures were examined by X-ray diffraction (XRD). Since hydrogenation of styrene is one of the important well-known chemical reactions, herein, we demonstrated then the catalytic hydrogenation capability of the Pt nanoparticles on graphene/graphite oxide for the nanocomposite to compare with that of the commercial catalysts (Pt/C and Pd/C, 10 wt.% metal catalysts on activated carbon from Strem chemicals, Inc.). The conversions with the Pt nanoparticles on graphene are >99% from styrene to ethyl benzene at 100°C and under 140 psi H2 atmosphere. However, ethyl cyclohexane could be found as a side product at 100°C and under 1,520 psi H2 atmosphere utilizing the same nanocomposite catalyst. PMID:24103100

  20. Synthesis, Characterization and Gas Sensing Properties of Ag@α-Fe2O3 Core–Shell Nanocomposites

    Directory of Open Access Journals (Sweden)

    Ali Mirzaei

    2015-05-01

    Full Text Available Ag@α-Fe2O3 nanocomposite having a core–shell structure was synthesized by a two-step reduction-sol gel approach, including Ag nanoparticles synthesis by sodium borohydride as the reducing agent in a first step and the subsequent mixing with a Fe+3 sol for α-Fe2O3 coating. The synthesized Ag@α-Fe2O3 nanocomposite has been characterized by various techniques, such as SEM, TEM and UV-Vis spectroscopy. The electrical and gas sensing properties of the synthesized composite towards low concentrations of ethanol have been evaluated. The Ag@α-Fe2O3 nanocomposite showed better sensing characteristics than the pure α-Fe2O3. The peculiar hierarchical nano-architecture and the chemical and electronic sensitization effect of Ag nanoparticles in Ag@α-Fe2O3 sensors were postulated to play a key role in modulating gas-sensing properties in comparison to pristine α-Fe2O3 sensors.

  1. One-pot synthesis of porous Fe{sub 3}O{sub 4} shell/silver core nanocomposites used as recyclable magnetic antibacterial agents

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Weijun, E-mail: wjfang81@gmail.com [College of Basic Medicine, Anhui Medical University, Hefei 230032, Anhui (China); Zheng, Jun; Chen, Cheng [Center of Modern Experimental Technology, Anhui University, Hefei 230039, Anhui (China); Zhang, Huabing; Lu, Yunxia [College of Basic Medicine, Anhui Medical University, Hefei 230032, Anhui (China); Ma, Ling [Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian (China); Chen, Guangjun [College of Basic Medicine, Anhui Medical University, Hefei 230032, Anhui (China)

    2014-05-01

    Porous Fe{sub 3}O{sub 4} shell/silver core nanocomposites featuring sustainable and recyclable antibacterial activity have been successfully prepared via a facile one-pot hydrothermal method. The unique structural feature of the Ag@Fe{sub 3}O{sub 4} nanocomposites with Ag embedded in porous Fe{sub 3}O{sub 4} shell endows them with the ability of sustained-release of silver ions. Their antimicrobial activity studies were investigated on both Gram negative Escherichia coli and Gram positive Bacillus subtilis, which demonstrate that the nanocomposites are highly toxic to microorganisms and exhibit sustainable antibacterial activity. Besides, the Ag@Fe{sub 3}O{sub 4} nanocomposites can be separated easily from the medium by a small magnet, which provided an effective way to eliminate the residual nanosilver from the surroundings. We finally demonstrate that the recovered nanocomposites exhibit recyclable antibacterial activity, acting as an ideal long-acting antibacterial agent. - Highlights: • The porous Fe{sub 3}O{sub 4} shell/silver core nanocomposites have been successfully prepared via a simple one-pot hydrothermal method. • The as-prepared Ag@Fe{sub 3}O{sub 4} nanocomposites exhibit high antibacterial activity against both Gram-positive and Gram-negative bacteria. • The porous Fe{sub 3}O{sub 4} shell/silver core nanocomposites show a stronger antibacterial ability than the solid Fe{sub 3}O{sub 4} shell/silver core nanocomposites. • The recovery nanocomposites still have antibacterial activity and can be reused.

  2. Synthesis of biogenic silicon/silica (Si/SiO2) nanocomposites from rice husks and wheat bran through various microorganisms

    Science.gov (United States)

    Kaur, Taranjot; Pal Singh, Gurwinder; Kaur, Gurneet; Kaur, Sukhvir; Gill, Prabhjot Kaur

    2016-08-01

    Biosilification is an economically viable, energy saving and green approach for the commercial scale synthesis of oxide nanomaterials. The room temperature synthesis of oxide nanocomposites from cost effective agro-based waste is a particular example of biosilification. In this study, synthesis of Si/SiO2 nanocomposites from inexpensive agro-based waste material i.e. rice husks (RH) and wheat bran (WB) has been carried out by means of various eukaryotic microorganisms, i.e. Actinomycete, Fusarium oxysporum, Aspergillus niger, Trichoderma sp. and Penicillium sp., under ambient conditions. The XRD diffrectrograms represents that the synthesized nanomaterials exhibits silicon, amorphous silica and other crystal arrays such as cristobalite, trydimite and quartz, depending upon the type microorganism and time period used for extraction. All of the aforesaid microorganism bio transformed the naturally occurring amorphous silica to crystalline structures within the period of 24 h. However, the Actinomycete and Trichoderma sp. took 48 h in case of rice husks for biotransformation of naturally occurring plant silica to crystalline nanocomposite. While in case of wheat bran, Actinomycete and Trichoderma sp. took 24 h for biotransformation. The extracted nanocomposites exhibits band edge in the range 230-250 nm and blue emission. The procedure described in study can be used for commercial level production of Si/SiO2 nanocomposites from agro based waste materials.

  3. Synthesis and characterization of nanocomposites based on PANI and carbon nanostructures prepared by electropolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Petrovski, Aleksandar; Paunović, Perica [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of); Avolio, Roberto; Errico, Maria E.; Cocca, Mariacristina; Gentile, Gennaro [Institute for Polymers, Composites and Biomaterials, National Research Council, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli (Italy); Grozdanov, Anita, E-mail: anita.grozdanov@yahoo.com [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of); Avella, Maurizio [Institute for Polymers, Composites and Biomaterials, National Research Council, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli (Italy); Barton, John [Tyndall National Institute, University College Cork, Dyke Parade, T12 R5CP, Cork (Ireland); Dimitrov, Aleksandar [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of)

    2017-01-01

    Nanocomposites based on polyaniline (PANI) and carbon nanostructures (CNSs) (graphene (G) and multiwall carbon nanotubes (MWCNTs)) were prepared by in situ electrochemical polymerization. CNSs were inserted into the PANI matrix by dispersing them into the electrolyte before the electropolymerization. Electrochemical characterization by means of cyclic voltammetry and steady state polarization were performed in order to determine conditions for electro-polymerization. Electro-polymerization of the PANI based nanocomposites was carried out at 0.75 V vs. saturated calomel electrode (SCE) for 40 and 60 min. The morphology and structural characteristics of the obtained nanocomposites were studied by scanning electron microscopy (SEM) and Raman spectroscopy, while thermal stability was determined using thermal gravimetric analysis (TGA). According to the morphological and structural study, fibrous and porous structure of PANI based nanocomposites was detected well embedding both G and MWCNTs. Also, strong interaction between quinoidal structure of PANI with carbon nanostructures via π–π stacking was detected by Raman spectroscopy. TGA showed the increased thermal stability of composites reinforced with CNSs, especially those reinforced with graphene. - Highlights: • Nanocomposites of PANI with carbon nanostructures were prepared for sensing application. • By cyclic voltammetry, conductive form of PANI (green colored emeraldine phase) is obtained 0.75 V • Using 4 Probe method, nanocomposite PANI/CNS tablet was tested for sensing application. • Micro-structural properties of nanocomposites were studied by SEM, TGA and Raman analysis.

  4. Synthesis, characterization and application of biodegradable crosslinked carboxymethyl chitosan/poly(vinyl alcohol) clay nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Sabaa, Magdy W.; Abdallah, Heba M.; Mohamed, Nadia A.; Mohamed, Riham R., E-mail: rihamrashad@hotmal.com

    2015-11-01

    Crosslinked poly(vinyl alcohol) (PVA)/carboxymethyl chitosan (CMCh) nanocomposites were synthesized using terephthaloyl diisothiocyanate crosslinker, in the presence of montmorillonite (MMT), in different ratios of the two matrices. Characterization of nanocomposites was performed using different analyses. Swelling behavior was studied in different buffered solutions. It was found that formation of crosslinked CMCh/PVA hydrogels increased the swellability. Metal ion adsorption has also been investigated. The results indicated that crosslinked CMCh adsorbs various metal ions much more than non crosslinked CMCh. Antimicrobial activity was examined against Gram positive bacteria, against Gram negative bacteria, and also against fungi. Results indicated that most of these nanocomposites exhibited good antimicrobial potency. Degradation study was carried out in Simulated Body Fluid (SBF) for different time periods in order to find out degradation index (Di). Results showed that weight loss of most of the nanocomposites increased as a function of incubation time. - Highlights: • CMCh/PVA nanocomposites have been evaluated for activity against bacteria and fungi. • TEM showed that these hydrogels have size 3–19 nm. • Nanocomposites increased metal ion uptake and showed selectivity for cadmium ions. • Biodegradation increased as a function of incubation time in SBF solution. • Biodegradation increased with increase in CMCh and clay in nanocomposites.

  5. Synthesis and utilization of poly (methylmethacrylate nanocomposites based on modified montmorillonite

    Directory of Open Access Journals (Sweden)

    Ahmed M. Youssef

    2017-07-01

    Full Text Available Poly (methylmethacrylate nanocomposite was prepared via in-situ emulsion polymerization (PMMA/Mt-CTA. The modified montmorillonite (Mt-CTA is used as hosts for the preparation of poly (methylmethacrylate nanocomposites with basal distance 1.95 nm. Moreover, exfoliated nanocomposite was characterized by X-ray diffraction (XRD, transmission electron microscope (TEM, thermal gravimetric analysis (TGA, and differential scanning calorimetry (DSC. The fashioned nanocomposites exhibited better thermal stability than pristine PMMA which make it suitable for packaging applications. Furthermore, this nanocomposite reveals tremendous affinity for removing pesticides from aquatic solutions. The data obtained from GC/ECD gas liquid chromatography illustrated that the removal efficiency of PMMA/Mt-CTA nanocomposites for organochlorine pesticides (OCPs varied from 73.65% to 99.36% that make it as a new method for water treatment. Also, the antimicrobial activity of the Mt-CTA and PMMA/Mt-CTA nanocomposites was evaluated by the inhibitory zone tests and revealed good activity against Escherichia coli and Staphylococcus aureus, which makes it suitable materials for packaging applications.

  6. Synthesis of Cu-CNTs nanocomposites via double pressing double sintering method

    Directory of Open Access Journals (Sweden)

    Marjan Darabi

    2018-01-01

    Full Text Available In this research, copper (Cu-carbon nanotubes (CNTs nanocomposites were synthesized with different weight percentages of CNTs by double pressing double sintering (DPDS method as well as conventional sintering method. A planetary ball mill was used to disperse CNTs in Cu matrix. The milled powders were first cold pressed to 450 MPa in a uniaxial stainless-steel die with cylindrical compacts (diameter: 12 mm and height: 5 mm. The effect of CNTs content and the DPDS method on the properties of the nanocomposites were investigated. The microstructure and phase analysis of Cu-CNTs nanocomposite samples were studied by FESEM and X-Ray Diffraction. The electrical conductivity of nanocomposites was measured and compared to both sintering methods. Mechanical properties of Cu-CNTs nanocomposites were characterized using bending strength and micro-hardness measurements. Enhancements of about 32% in bending strength, 31.6% in hardness and 19.5% in electrical conductivity of Cu-1 wt.% CNTs nanocomposite synthesized by DPDS method were observed as compared to Cu-1 wt.% CNTs nanocomposites fabricated under the similar condition by a conventional sintering process.

  7. A novel intumescent flame retardant-functionalized graphene: Nanocomposite synthesis, characterization, and flammability properties

    International Nuclear Information System (INIS)

    Huang, Guobo; Chen, Suqing; Tang, Shouwan; Gao, Jianrong

    2012-01-01

    An intumescent flame retardant, poly(piperazine spirocyclic pentaerythritol bisphosphonate) (PPSPB), has been covalently grafted onto the surfaces of graphene oxide (GO) to obtain GO–PPSPB and according nanocomposites were prepared via solvent blending. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that the chemically reduced GO–PPSPB (CRG–PPSPB) can achieve better dispersion in the ethylene vinyl acetate copolymer (EVA) matrix and exfoliated EVA/CRG–PPSPB nanocomposites are formed. The results from thermogravimetric analysis (TGA) and cone calorimeter tests indicate that CRG–PPSPB improve thermal stability and reduce obviously the flammability (including peak heat release rate (PHRR), total heat release (THR), average mass loss rate (AMLR), etc.) of EVA. Compared with pure EVA resin, the PHRR of the EVA/CRG–PPSPB nanocomposites filled with 1 wt% CRG–PPSPB is reduced by about 56%. The SEM images show that a compact, dense and uniform intumescent char is formed for EVA/CRG–PPSPB nanocomposites after combustion. The functionalization of graphene by intumescent flame retardant PPSPB can improve both the dispersion of graphene sheets in the polymer matrix and flame retardancy of the nanocomposites. -- Highlights: ► Graphene oxide were modified with intumescent flame retardant PPSPB. ► EVA/CRG–PPSPB nanocomposites were prepared via solvent blending. ► CRG–PPSPB improved the flame retardancy of EVA nanocomposites.

  8. Synthesis and spectroscopic characterization of magnetic hydroxyapatite nanocomposite using ultrasonic irradiation

    Science.gov (United States)

    Gopi, D.; Ansari, M. Thameem; Shinyjoy, E.; Kavitha, L.

    2012-02-01

    Nowadays magnetic hydroxyapatite (m-HAP) has potential applications in biomedicine more especially for bone cancer treatment. In this paper the functionalization of the hydroxyapatite (HAP) with magnetite nanoparticle (MNP) through ultrasonic irradiation technique is reported and its spectral investigation has been carried out. The ultrasonic irradiation with two different frequencies of 28 kHz and 35 kHz at the power of 150 and 320 W, respectively, was employed for the synthesis of m-HAP. The ultrasound irradiation of 35 kHz at 320 W shows the efficient diffusion of MNP to the HAP host matrix leads to the formation of m-HAP. The ultrasonic irradiation technique does not require stabilizers as in the case of coprecipitation method hence the final product of pure m-HAP is obtained. The X-ray diffraction pattern shows the formation of magnetite nanoparticles which are functionalized with hydroxyapatite host matrix. The vibrating sample magnetometer curve exhibits the super paramagnetic property of the samples and the saturation magnetization ( Ms) value of the functionalized magnetic hydroxyapatite. The Ms value is found to be much less than that of pure magnetite nanoparticle and this decrement in Ms is due to the hindrance of magnetic domain of the particles with HAP. The portrayed Raman spectra discriminate between the m-HAP and MNP with corresponding vibrational modes of frequencies. The transmission electron micrograph shows excellent morphology of functionalized m-HAP in nanometer range. The atomic force microscopic investigation shows the 3-dimensional view of crust and trench shape of m-HAP. All these results confirm the formation of magnetic hydroxyapatite nanocomposite with typical magnetic property for biological applications.

  9. Polyacrolein/mesoporous silica nanocomposite: Synthesis, thermal stability and covalent lipase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Motevalizadeh, Seyed Farshad; Khoobi, Mehdi; Shabanian, Meisam [Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14176 (Iran, Islamic Republic of); Asadgol, Zahra; Faramarzi, Mohammad Ali [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences, P.O. Box 14155-6451, Tehran 14176 (Iran, Islamic Republic of); Shafiee, Abbas, E-mail: ashafiee@ams.ac.ir [Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14176 (Iran, Islamic Republic of); Center of Excellence in Biothermodynamics, University of Tehran, Tehran (Iran, Islamic Republic of)

    2013-12-16

    In this work, new polyacrolein/MCM-41 nanocomposites with good phase mixing behavior were prepared through an emulsion polymerization technique. Mesoporous silica was synthesized by in situ assembly of tetraethyl orthosilicate (TEOS) and cetyl trimethyl ammonium bromide (CTAB). The structure and properties of polyacrolein containing nanosized MCM-41 particle (5 and 10 wt%), were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, Dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N{sub 2} adsorption techniques, and thermogravimetric (TGA) analyses. The SEM images from the final powder have revealed good dispersion of the MCM-41 nanoparticles throughout polymeric matrix with no distinct voids between two phases. The results indicated that the thermal properties of the nanocomposite were enhanced by addition of MCM-41. Thermomyces lanuginosa lipase (TLL) was used as a model biocatalyst and successfully immobilized with polyacrolein and the nanocomposite via covalent bonds with the aldehyde groups. The activity between free enzyme, polyacrolein, and MCM-41 nanocomposite (10 wt%)-immobilized TLL was compared. The immobilized lipase with the nanocomposite shows better operational stability such as pH tolerance, thermal and storage stability. In addition, the immobilized lipase with the nanocomposite can be easily recovered and retained at 74% of its initial activity after 15 time reuses. - Graphical abstract: The influence of incorporation of mesoporous MCM-41 nanoparticle with polyacrolein on the thermal properties and enzyme immobilization was investigated. - Highlights: • Polyacrolein/MCM-41 nanocomposites were prepared by emulsion polymerization method. • Thermal stability and char residues in nanocomposites were improved. • Nanocomposites significant effects on immobilization of lipase.

  10. Synthesis of polystyrene@(silver-polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Science.gov (United States)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu

    2015-01-01

    We reported the synthesis of polystyrene@(silver-polypyrrole) (PS@(Ag-PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag+ and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA)2]+) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO3 and Py, the introduction of [Ag(TEA)2]+ ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag-PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA)2]+ ions resulted in the increase of Ag-PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag-PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 105 - 9×105 cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag-PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.

  11. Synthesis and carbon dioxide sorption of layered double hydroxide/silica foam nanocomposites with hierarchical mesostructure

    KAUST Repository

    Fu, Liling; Qi, Genggeng; Shekhah, Osama; Belmabkhout, Youssef; Esté vez, Luis Antonio; Eddaoudi, Mohamed; Giannelis, Emmanuel P.

    2014-01-01

    Layered double hydroxides (LDHs) with a hierarchical mesostructure are successfully synthesized on mesoporous silica foams by simple impregnation and hydrothermal treatment. The as-synthesized LDH/silica foam nanocomposites show well-defined mesostructures with high surface areas, large pore volumes, and mesopores of 6-7 nm. The nanocomposites act as carbon dioxide (CO2) sorbents under simulated flue gas conditions. They also exhibit significantly enhanced CO2 capacities under high-pressure conditions and high CO2/N2 and CO2/CH4 selectivities. Respect the hierarchy: Hierarchical mesoporous layered double hydroxide (LDH) nanocomposites with high surface areas and large pore volumes are synthesized by controlled hydrothermal growth of LDH precursors on a mesoporous silica foam. The as-synthesized nanocomposites exhibit a significantly enhanced capacity and selectivity towards carbon dioxide, making them very promising candidates for carbon dioxide (CO2) separation applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Synthesis and characterization of polyurethane/CdS-SiO 2 nanocomposites via ultrasonic process

    Science.gov (United States)

    Chen, Jing; Zhou, Yu-Ming; Nan, Qiu-Li; Ye, Xiao-Yun; Sun, Yan-Qing; Wang, Zhi-Qiang; Zhang, Shi-Ming

    2008-12-01

    In this study, the high-intensity ultrasound was applied in the preparation of chiral polyurethane/CdS-SiO 2 nanocomposites. The polyurethane/CdS-SiO 2 nanocomposites were analyzed by powder X-ray diffraction, thermogravimetric analysis (TGA), TEM and SEM. The results indicated that the heat stability of the nanocomposites was improved in the presence of CdS-SiO 2 core-shell nanoparticles. The infrared emissivity (8-14 μm) study revealed that the nanocomposites possessed much lower infrared values compared with those of the neat polymers and nanoparticles, respectively. A possible mechanism of ultrasonic induced composite reaction was proposed based on the experimental results.

  13. Synthesis and characterization of polyurethane/CdS-SiO2 nanocomposites via ultrasonic process

    International Nuclear Information System (INIS)

    Chen Jing; Zhou Yuming; Nan Qiuli; Ye Xiaoyun; Sun Yanqing; Wang Zhiqiang; Zhang Shiming

    2008-01-01

    In this study, the high-intensity ultrasound was applied in the preparation of chiral polyurethane/CdS-SiO 2 nanocomposites. The polyurethane/CdS-SiO 2 nanocomposites were analyzed by powder X-ray diffraction, thermogravimetric analysis (TGA), TEM and SEM. The results indicated that the heat stability of the nanocomposites was improved in the presence of CdS-SiO 2 core-shell nanoparticles. The infrared emissivity (8-14 μm) study revealed that the nanocomposites possessed much lower infrared values compared with those of the neat polymers and nanoparticles, respectively. A possible mechanism of ultrasonic induced composite reaction was proposed based on the experimental results.

  14. Synthesis and carbon dioxide sorption of layered double hydroxide/silica foam nanocomposites with hierarchical mesostructure

    KAUST Repository

    Fu, Liling

    2014-03-05

    Layered double hydroxides (LDHs) with a hierarchical mesostructure are successfully synthesized on mesoporous silica foams by simple impregnation and hydrothermal treatment. The as-synthesized LDH/silica foam nanocomposites show well-defined mesostructures with high surface areas, large pore volumes, and mesopores of 6-7 nm. The nanocomposites act as carbon dioxide (CO2) sorbents under simulated flue gas conditions. They also exhibit significantly enhanced CO2 capacities under high-pressure conditions and high CO2/N2 and CO2/CH4 selectivities. Respect the hierarchy: Hierarchical mesoporous layered double hydroxide (LDH) nanocomposites with high surface areas and large pore volumes are synthesized by controlled hydrothermal growth of LDH precursors on a mesoporous silica foam. The as-synthesized nanocomposites exhibit a significantly enhanced capacity and selectivity towards carbon dioxide, making them very promising candidates for carbon dioxide (CO2) separation applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Synthesis and Characterization of Bovine Serum Albumin-Conjugated Copper Sulfide Nanocomposites

    Directory of Open Access Journals (Sweden)

    Peng Huang

    2010-01-01

    Full Text Available A simple biomolecule-assisted solution route was developed to synthesize Bovine Serum Albumin-conjugated copper sulfide (CuS/BSA nanocomposites, directly using copper salts and thioacetamide (TAA as the starting materials with a zwitterionic surfactant Bovine Serum Albumin (BSA as foaming and stabilizing agent. The CuS/BSA nanocomposites have been characterized by UV, TEM, Zeta, DLS, XRD, and FTIR. The results indicate that the as-prepared CuS/BSA nanocomposites are approximate sphere with a size distribution from 10 to 35 nm in diameter and good dispersibility, depending highly on concentration of BSA concentration. These protein-assisted synthesized nanocomposites have a great potential application in biomedical engineering and microelectronics.

  16. One-Pot Hydrothermal Synthesis of Magnetite Prussian Blue Nano-Composites and Their Application to Fabricate Glucose Biosensor

    Directory of Open Access Journals (Sweden)

    Ezzaldeen Younes Jomma

    2016-02-01

    Full Text Available In this work, we presented a simple method to synthesize magnetite Prussian blue nano-composites (Fe3O4-PB through one-pot hydrothermal process. Subsequently, the obtained nano-composites were used to fabricate a facile and effective glucose biosensor. The obtained nanoparticles were characterized using transmission electron microscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, UV-vis absorbance spectroscopy, cyclic voltammetry and chronoamperometry. The resultant Fe3O4-PB nanocomposites have magnetic properties which could easily controlled by an external magnetic field and the electro-catalysis of hydrogen peroxide. Thus, a glucose biosensor based on Fe3O4-PB was successfully fabricated. The biosensor showed super-electrochemical properties toward glucose detection exhibiting fast response time within 3 to 4 s, low detection limit of 0.5 µM and wide linear range from 5 µM to 1.2 mM with sensitivity of 32 µA∙mM−1∙cm−2 and good long-term stability.

  17. Sonochemical synthesis and high lithium storage properties of ordered Co/CMK-3 nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Hui, E-mail: huiqiaoz@163.com [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Department of Electrical Engineering and Computer Sciences, South Dakota State University, Brookings, SD 57007 (United States); Xia, Zhaokang; Liu, Yanhua [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Cui, Rongrong, E-mail: cuirong3243@sina.com [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Fei, Yaqian; Cai, Yibing; Wei, Qufu [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Yao, Qingxia [School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, 252000 (China); Qiao, Qiquan, E-mail: qiquan.qiao@sdstate.edu [Department of Electrical Engineering and Computer Sciences, South Dakota State University, Brookings, SD 57007 (United States)

    2017-04-01

    Graphical abstract: A novel ordered Co/CMK-3 nanocomposite was successfully synthesized via the sonochemical method followed by carbonization process. The lithium storage properties demonstrated that ordered Co/CMK-3 nanocomposites possessed high reversible capacity and cycling stability. Moreover, the ordered Co/CMK-3 nanocomposites electrode also exhibits high capacity at higher charge/discharge rate. - Highlights: • A novel ordered Co/CMK-3 nanocomposite was successfully synthesized via the sonochemical method followed by carbonization process. • The lithium storage properties shows that the ordered Co/CMK-3 nanocomposites exhibit a large reversible capacity and good cycle stability with the capacity of 720 mAh g{sup −1} after 50 cycles. • The ordered Co/CMK-3 nanocomposites also showed high capacity at higher discharge and charge rate. - Abstract: A novel ordered Co/CMK-3 nanocomposite was successfully synthesized via the sonochemical method followed by carbonization process. The ordered Co/CMK-3 nanocomposite were characterized by X-ray diffraction, transmission electron microscopy and N{sub 2} adsorption–desorption analysis techniques. The lithium storage properties shows that the Co/CMK-3 nanocomposites exhibit a large reversible capacity and good cycle stability with the capacity of 720 mAh g{sup −1} after 50 cycles at a current rate of 50 mA g{sup −1}, much higher than that of original CMK-3 electrode. The Co/CMK-3 nanocomposites also demonstrates an excellent rate capability with capacity of 479 mAh g{sup −1} even at a current density of 1000 mA g{sup −1} after 50 cycles. The improved lithium storage properties of ordered Co/CMK-3 nanocomposites can be attributed to the CMK-3 could restrain the aggregation of Co nanoparticles, the large surface area of the mesopores in which the Co nanoparticles are formed, as well as presence of Co which played the role of catalyst could promote the lithium storage reaction.

  18. Aqueous synthesis of ZnTe/dendrimer nanocomposites and their antimicrobial activity: implications in therapeutics

    Science.gov (United States)

    Ghosh, S.; Ghosh, D.; Bag, P. K.; Bhattacharya, S. C.; Saha, A.

    2011-03-01

    The present strategy proposes a simple and single step aqueous route for synthesizing stable, fluorescent ZnTe/dendrimer nanocomposites with varying dendrimer terminal groups. In these hybrid materials, the fluorescence of the semiconductor combines with the biomimetic properties of the dendrimer making them suitable for various biomedical applications. The ZnTe nanocomposites thus obtained demonstrate bactericidal activity against enteropathogenic bacteria without having toxic effects on the human erythrocytes. The average size of the ZnTe nanoparticles within the dendrimer matrix was in the range of 2.9-6.0 nm, and they have a good degree of crystallinity with a hexagonal crystal phase. The antibacterial activities of the ZnTe/dendrimer nanocomposites (ZnTe DNCs) as well other semiconductor nanocomposites were evaluated against enteropathogenic bacteria including multi-drug resistant Vibrio cholerae serogroup O1 and enterotoxigenic Escherichia coli (ETEC). ZnTe DNCs had significant antibacterial activity against strains of V. cholerae and ETEC with minimum inhibitory concentrations ranging from 64 to 512 μg ml-1 and minimum bactericidal concentrations ranging from 128 to 1000 μg ml-1. Thus, the observed results suggest that these water-soluble active nanocomposites have potential for the treatment of enteric diseases like diarrhoea and cholera.The present strategy proposes a simple and single step aqueous route for synthesizing stable, fluorescent ZnTe/dendrimer nanocomposites with varying dendrimer terminal groups. In these hybrid materials, the fluorescence of the semiconductor combines with the biomimetic properties of the dendrimer making them suitable for various biomedical applications. The ZnTe nanocomposites thus obtained demonstrate bactericidal activity against enteropathogenic bacteria without having toxic effects on the human erythrocytes. The average size of the ZnTe nanoparticles within the dendrimer matrix was in the range of 2.9-6.0 nm, and they

  19. Sonochemical synthesis and high lithium storage properties of ordered Co/CMK-3 nanocomposites

    International Nuclear Information System (INIS)

    Qiao, Hui; Xia, Zhaokang; Liu, Yanhua; Cui, Rongrong; Fei, Yaqian; Cai, Yibing; Wei, Qufu; Yao, Qingxia; Qiao, Qiquan

    2017-01-01

    Graphical abstract: A novel ordered Co/CMK-3 nanocomposite was successfully synthesized via the sonochemical method followed by carbonization process. The lithium storage properties demonstrated that ordered Co/CMK-3 nanocomposites possessed high reversible capacity and cycling stability. Moreover, the ordered Co/CMK-3 nanocomposites electrode also exhibits high capacity at higher charge/discharge rate. - Highlights: • A novel ordered Co/CMK-3 nanocomposite was successfully synthesized via the sonochemical method followed by carbonization process. • The lithium storage properties shows that the ordered Co/CMK-3 nanocomposites exhibit a large reversible capacity and good cycle stability with the capacity of 720 mAh g"−"1 after 50 cycles. • The ordered Co/CMK-3 nanocomposites also showed high capacity at higher discharge and charge rate. - Abstract: A novel ordered Co/CMK-3 nanocomposite was successfully synthesized via the sonochemical method followed by carbonization process. The ordered Co/CMK-3 nanocomposite were characterized by X-ray diffraction, transmission electron microscopy and N_2 adsorption–desorption analysis techniques. The lithium storage properties shows that the Co/CMK-3 nanocomposites exhibit a large reversible capacity and good cycle stability with the capacity of 720 mAh g"−"1 after 50 cycles at a current rate of 50 mA g"−"1, much higher than that of original CMK-3 electrode. The Co/CMK-3 nanocomposites also demonstrates an excellent rate capability with capacity of 479 mAh g"−"1 even at a current density of 1000 mA g"−"1 after 50 cycles. The improved lithium storage properties of ordered Co/CMK-3 nanocomposites can be attributed to the CMK-3 could restrain the aggregation of Co nanoparticles, the large surface area of the mesopores in which the Co nanoparticles are formed, as well as presence of Co which played the role of catalyst could promote the lithium storage reaction.

  20. Mesoporous binary metal oxide nanocomposites: Synthesis, characterization and decontamination of sulfur mustard

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, J., E-mail: praveenjella10@gmail.com; Prasad, G.K.; Ramacharyulu, P.V.R.K.; Singh, Beer; Gopi, T.; Krishna, R.

    2016-04-15

    Mesoporous MnO{sub 2}–ZnO, Fe{sub 2}O{sub 3}–ZnO, NiO–ZnO, and CeO{sub 2}–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard. They were synthesized by precipitation pyrolysis method and characterized by means of transmission electron microscopy, scanning electron microscopy coupled with energy dispersive analysis of X rays, X ray diffraction, and nitrogen adsorption techniques. The transmission electron microscopy and nitrogen adsorption data indicated the presence of pores with diameter ranging from 10 to 70 nm in the binary metal oxide nanocomposites and these materials exhibited surface area values in the range of 76–134 m{sup 2}/g. These binary metal oxide nanocomposites demonstrated large decontamination efficiencies against sulfur mustard when compared to their single component metal oxide nanoparticles. The binary metal oxide nanocomposites effectively decontaminated sulfur mustard into relatively non toxic products such as chloro ethyl vinyl sulfide, divinyl sulfide, 1,4-oxathiane, etc. The promising decontamination properties of binary metal oxide nanocomposites against sulfur mustard were attributed to the basic sites, Lewis acid sites, and the presence of these sites was confirmed by CO{sub 2} and NH{sub 3} temperature programmed desorption. - Graphical abstract: Mesoporous MnO{sub 2}–ZnO, Fe{sub 2}O{sub 3}–ZnO, NiO–ZnO, and CeO{sub 2}–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard. - Highlights: • Binary metal oxide nanocomposites were synthesized by co-precipitation method. • They were studied as sorbent decontaminants against sulfur mustard. • They decontaminated sulfur mustard into non toxic products. • MnO{sub 2}–ZnO and CeO{sub 2}–ZnO nanocomposites showed greater decontamination efficiency.

  1. Synthesis of polymer gel electrolyte with high molecular weight poly(methyl methacrylate)-clay nanocomposite

    International Nuclear Information System (INIS)

    Meneghetti, Paulo; Qutubuddin, Syed; Webber, Andrew

    2004-01-01

    Polymer nanocomposite gel electrolytes consisting of high molecular weight poly(methyl methacrylate) PMMA-clay nanocomposite, ethylene carbonate (EC)/propylene carbonate (PC) as plasticizer, and LiClO 4 electrolyte are reported. Montmorillonite clay was ion exchanged with a zwitterionic surfactant (octadecyl dimethyl betaine) and dispersed in methyl methacrylate, which was then polymerized to synthesize PMMA-clay nanocomposites. The nanocomposite was dissolved in a mixture of EC/PC with LiClO 4 , heated and pressed to obtain polymer gel electrolyte. X-ray diffraction (XRD) of the gels indicated intercalated clay structure with d-spacings of 2.85 and 1.40 nm. In the gel containing plasticizer, the clay galleries shrink suggesting intercalation rather than partial exfoliation observed in the PMMA-clay nanocomposite. Ionic conductivity varied slightly and exhibited a maximum value of 8 x 10 -4 S/cm at clay content of 1.5 wt.%. The activation energy was determined by modeling the conductivity with a Vogel-Tamman-Fulcher expression. The clay layers are primarily trapped inside the polymer matrix. Consequently, the polymer does not interact significantly with LiClO 4 electrolyte as shown by FTIR. The presence of the clay increased the glass transition temperature (Tg) of the gel as determined by differential scanning calorimetry. The PMMA nanocomposite gel electrolyte shows a stable lithium interfacial resistance over time, which is a key factor for use in electrochemical applications

  2. Synthesis, characterization and thermal analysis of polyimide-cobalt ferrite nanocomposites

    International Nuclear Information System (INIS)

    Mazuera, David; Perales, Oscar; Suarez, Marcelo; Singh, Surinder

    2010-01-01

    Research highlights: · Polyimide-cobalt ferrite nanocomposites were successfully produced. · Produced nanocomposites are suitable for use at temperatures below 80 deg. C. · Magnetic properties of nanocomposites were no sensitive to particle agglomeration. · Good distribution of clustered nanoparticles was achieved in produced composites. - Abstract: Cobalt ferrite nanocrystals were synthesized under size-controlled conditions in aqueous phase and incorporated into a polyimide matrix at various volumetric loads. Synthesized 20 nm cobalt ferrite single crystals, which exhibited a room-temperature coercivity of 2.9 kOe, were dispersed in polyimide precursor using two techniques: homogenizer and ball milling. These suspensions were then cured to develop the polyimide structure in the resulting nanocomposites. Produced films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and vibrating sample magnetometry, which confirmed the formation of the desired phases. As expected, the saturation magnetization in the nanocomposites varied according to the polyimide/ferrite weight ratio, while coercivity remained at the value corresponding to pure cobalt ferrite nanocrystals. Thermal degradation, thermal stability and dynamic mechanical analyses tests were also carried out to assess the effect of the concentration of the ferrite disperse phase on the thermo-mechanical behavior of the corresponding nanocomposites as well as the used dispersion techniques.

  3. Synthesis of graphene oxide-copper molybdate (GO-CuM) nanocomposites for photocatalytic application

    Science.gov (United States)

    Singh, Gajendar; Bhargava, V. Sai; Sharma, Manu

    2018-05-01

    Transition metal molybdates (TMBs) MMoO4 (M=Ni, Cu, Fe, Zn, Co, etc.) based nanocomposites have been considered as remarkable materials in the field of electronics, optics, catalysis, supercapicitors and energy storage devices. Nanocomposites of TMBs with graphene oxide have also been chosen as an effective material in photocatalytic application. GO-CuM nanocomposites were synthesized by ultra-sonication method at RT, followed by reflux route for preparation of CuM and GO by modified Hemmer's method. As prepared nanocomposites were characterized using analytical techniques such as PXRD, SEM, FT-IR and UV-Visible spectroscopy. The enhanced photocatalytic activity of Methylene blue (MB) dye was observed by GO-CuM nanocomposites as compared to pure copper molybdate. GO-CuM nanocomposites show high photodegradation rate (0.094 min-1) whereas CuM was degraded only 30 % with the rate of 0.0029 min-1. The high photocatalytic efficiency is due to the presence of graphene oxide that helps to delay the charge recombination in photocatalytic reaction The effect of the different amount of graphene oxide on the photocatalytic activity of as prepared photocatalyst has also been investigated.

  4. Synthesis and evaluation of gas sensing properties of PANI based graphene oxide nanocomposites

    International Nuclear Information System (INIS)

    Gaikwad, Ganesh; Patil, Pritam; Patil, Devidas; Naik, Jitendra

    2017-01-01

    Highlights: • Developed GO, ZnO, PANI nanocomposites. • Evaluated for effect of GO addition on gas sensing performance. • Performed ammonia gas sensing at room temperature. • Obtained excellent recovery time of gas sensor. - Abstract: Polyaniline (PANI) nanofibers and Polyaniline/Graphene Oxide (PANI/GO), Polyaniline/Graphene Oxide/Zinc Oxide (PANI/GO/ZnO) nanocomposites were successfully prepared by nanoemulsion method. The synthesized nanofibers and nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Field emission scanning electron microscope (FE-SEM), has showed the evidence of interaction between PANI nanofibers, GO nanosheets and ZnO nanoparticles, respectively. PANI nanofibers and nanocomposites were used for the sensing of NH_3_, LPG, CO_2 and H_2S gases respectively at room temperature. It was observed that the PANI nanofibers and PANI/GO, PANI/GO/ZnO nanocomposites with different weight ratios of ZnO and GO had better selectivity and sensitivity towards NH_3 at room temperature. Best performance was shown by PANI/GO/ZnO nanocomposite response of 5.706 (10.3 times better response than PANI sensor) for 1000 ppm NH_3 at 80 ± 1 °C with the recovery time of 1 min 30 s only.

  5. Synthesis and evaluation of gas sensing properties of PANI based graphene oxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Gaikwad, Ganesh [Department of Chemical Engineering, University Institute of Chemical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra (India); Patil, Pritam [SVMIT, College of Engineering, Bharuch 392001, Gujarat (India); Patil, Devidas [Bulk and Nanomaterials Research Laboratory, Rani Laxmibai Mahavidyalaya Parola, Jalgaon 425111, Maharashtra (India); Naik, Jitendra, E-mail: jbnaik@nmu.ac.in [Department of Chemical Engineering, University Institute of Chemical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra (India)

    2017-04-15

    Highlights: • Developed GO, ZnO, PANI nanocomposites. • Evaluated for effect of GO addition on gas sensing performance. • Performed ammonia gas sensing at room temperature. • Obtained excellent recovery time of gas sensor. - Abstract: Polyaniline (PANI) nanofibers and Polyaniline/Graphene Oxide (PANI/GO), Polyaniline/Graphene Oxide/Zinc Oxide (PANI/GO/ZnO) nanocomposites were successfully prepared by nanoemulsion method. The synthesized nanofibers and nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Field emission scanning electron microscope (FE-SEM), has showed the evidence of interaction between PANI nanofibers, GO nanosheets and ZnO nanoparticles, respectively. PANI nanofibers and nanocomposites were used for the sensing of NH{sub 3,} LPG, CO{sub 2} and H{sub 2}S gases respectively at room temperature. It was observed that the PANI nanofibers and PANI/GO, PANI/GO/ZnO nanocomposites with different weight ratios of ZnO and GO had better selectivity and sensitivity towards NH{sub 3} at room temperature. Best performance was shown by PANI/GO/ZnO nanocomposite response of 5.706 (10.3 times better response than PANI sensor) for 1000 ppm NH{sub 3} at 80 ± 1 °C with the recovery time of 1 min 30 s only.

  6. Green synthesis of magnetic chitosan nanocomposites by a new sol–gel auto-combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, Fatemeh [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317–51167, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of); Sobhani, Azam [Department of Chemistry, Kosar University of Bojnord, Bojnord, Islamic Republic of Iran (Iran, Islamic Republic of); Salavati-Niasari, Masoud, E-mail: salavati@kashanu.ac.ir [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317–51167, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of)

    2016-07-15

    The Fe{sub 2}O{sub 3}/CuFe{sub 2}O{sub 4}/chitosan nanocomposites have been successfully synthesized via a new sol–gel auto-combustion route. To prepare the nanocomposites, copper ferrite (CuFe{sub 2}O{sub 4}) and iron (II) oxide (Fe{sub 2}O{sub 3}) nanostructures were first prepared utilizing onion as a green reductant for the first time, and characterized by SEM, TEM, XRD, IR and VSM. Then chitosan was added into the nanostructures dispersed in water. Chitosan was used to functionalize and modify the nanostructures and also to improve surface properties. The nanocomposites were also characterized by several techniques including SEM, TEM, XRD, IR and VSM. The effects of amount of onion and chitosan on the morphology and particle size of nanocomposites were evaluated. - Highlights: • Fe{sub 2}O{sub 3}/CuFe{sub 2}O{sub 4}/chitosan nanocomposites were synthesized for the first time. • A simple, low-cost and friendly route was used to synthesize the nanocomposites. • Effects of amount of onion and chitosan were investigated.

  7. Facile synthesis of water-soluble curcumin nanocrystals

    Directory of Open Access Journals (Sweden)

    Marković Zoran M.

    2015-01-01

    Full Text Available In this paper, facile synthesis of water soluble curcumin nanocrystals is reported. Solvent exchange method was applied to synthesize curcumin nanocrystals. Different techniques were used to characterize the structural and photophysical properties of curcumin nanocrystals. We found that nanocurcumin prepared by this method had good chemical and physical stability, could be stored in the powder form at room temperature, and was freely dispersible in water. It was established that the size of curcumin nanocrystals was varied in the range of 20-500 nm. Fourier transform infrared spectroscopy and UV-Vis analyses showed the presence of tetrahydrofuran inside the curcumin nanocrystals. Also, it was found that nanocurcumin emitted photoluminescencewith yellow-green colour. [Projekat Ministarstva nauke Republike Srbije, br. 172003

  8. TiO{sub 2}/N-graphene nanocomposite via a facile in-situ hydrothermal sol–gel strategy for visible light photodegradation of eosin Y

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yingliang; Pei, Fuyun, E-mail: xusg@zzu.edu.cn; Lu, Ruijuan; Xu, Shengang; Cao, Shaokui, E-mail: caoshaokui@zzu.edu.cn

    2014-12-15

    Highlights: • TiO{sub 2}/N-graphene is synthesized via in-situ hydrothermal sol–gel strategy. • TiO{sub 2} nanoparticles are chemically anchored on N-graphene nanosheets. • The band gap of TiO{sub 2}/N-graphene is red-shifted from neat TiO{sub 2} nanoparticles. • 5-NGT nanocomposite has the best visible light photodegradation performance. - Abstract: TiO{sub 2}/N-graphene nanocomposites are synthesized via a facile in-situ hydrothermal sol–gel strategy in order to improve the photocatalytic efficiency for pollutant photodegradation under visible light irradiation. The as-prepared nanocomposites are respectively characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and UV–vis diffuse reflectance spectroscopy. Results indicated that neat TiO{sub 2} nanoparticles have an average diameter about 6.70 nm while TiO{sub 2} nanoparticles in TiO{sub 2}/N-graphene nanocomposites synthesized through in-situ hydrothermal sol–gel strategy bear an average diameter of ∼1 nm and are anchored on N-graphene nanosheets via chemical bonding. Both neat TiO{sub 2} nanoparticles and chemically anchored TiO{sub 2} nanoparticles in TiO{sub 2}/N-graphene nanocomposites take on the crystal type of anatase. The band gap of TiO{sub 2}/N-graphene nanocomposites is red-shifted compared with neat TiO{sub 2} nanoparticles. The evaluation of photodegradation performance under visible light irradiation suggested that the nanocomposite with 5 wt% N-graphene content has the best visible light photodegradation performance.

  9. Synthesis and Characterization of Nanoparticles and Nanocomposite of ZnO and MgO by Sonochemical Method and their Application for Zinc Polycarboxylate Dental Cement Preparation

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Karimi

    2011-01-01

    Full Text Available This paper discusses the synthesis of nanoparticles of ZnO and MgO and ZnO/MgO nanocomposite by the sonochemical method. At first, nanoparticles were synthesized by the reaction of Zn(CHCOO32 and Mg(CHCOO32 with tetramethylammonium hydroxide (TMAH in the presence of polyvinyl pyrrolidone (PVP and constant frequency ultrasonic waves (sonochemical method. Then, ZnO/MgO nanocomposite was prepared through reaction of magnesium acetate with TMAH in the presence of ZnO nanoparticles and PVP as structure director using ultrasonic assisted method. After filtration, the synthesized solution was obtained containing magnesium hydroxide in the presence of ZnO nanoparticles. It was calcinated at the temperature of 550 ºC, so that ZnO/MgO nanocomposite could be produced. The effects of different parameters on particle size and morphology of final ZnO and MgO powders and ZnO/MgO nanocomposite were optimized by ‘‘one at a time’’ method. Under optimum conditions, spongy shaped, uniformed and homogeneous nanostructured zinc oxide and magnesium oxide powders were obtained with particle sizes of 25–50 and 30-60 nm, respectively. ZnO/MgO nanocomposite was also obtained with more spongy morphology and particle size about 65 nm. Both synthesized ZnO and MgO nanoparticles and ZnO/MgO nanocomposite were successfully applied to the preparation of zinc polycarboxylate dental cement.

  10. Direct Synthesis and Morphological Characterization of Gold-Dendrimer Nanocomposites Prepared Using PAMAM Succinamic Acid Dendrimers: Preliminary Study of the Calcification Potential

    Directory of Open Access Journals (Sweden)

    E. Vasile

    2014-01-01

    Full Text Available Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach based on the use of polyamidoamine dendrimers with succinamic acid terminal groups and dodecanediamine core. Spherical and highly crystalline nanoparticles with dimensions between 3 nm and 60 nm, and size-polydispersity depending on the synthesis conditions, have been generated. The influence of the stoichiometric ratio and the structural and architectural features of the dendrimers on the properties of the nanocomposites has been described. The self-assembling behaviour of these materials produces gold-dendrimer nanostructured porous networks with variable density, porosity, and composition. The investigations of the reaction systems, by TEM, at two postsynthesis moments, allowed to preliminary establish the control over the properties of the nanocomposite products. Furthermore, this study allowed better understanding of the mechanism of nanocomposite generation. Impressively, in the early stages of the synthesis, the organization of gold inside the dendrimer molecules has been evidenced by micrographs. Growth and ripening mechanisms further lead to nanoparticles with typical characteristics. The potential of such nanocomposite particles to induce calcification when coating a polymer substrate was also investigated.

  11. In situ microemulsion synthesis of hydroxyapatite-MgFe{sub 2}O{sub 4} nanocomposite as a magnetic drug delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Foroughi, Firoozeh [Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of); Hassanzadeh-Tabrizi, S.A., E-mail: tabrizi1980@gmail.com [Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of); Bigham, Ashkan [Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of)

    2016-11-01

    In this study, an innovative synthesis process has been developed to produce hydroxyapatite-magnesium ferrite (HA-MgFe{sub 2}O{sub 4}) nanocomposite. In addition, the effect of calcination temperature on drug delivery behavior of produced samples was investigated. HA-MgFe{sub 2}O{sub 4} nanocomposite was prepared via one-step modified reverse microemulsion synthesis route. The resulting products were characterized by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller surface area analysis (BET). The calcined samples at 500 and 700 °C demonstrated mesoporous characteristics and large specific surface areas of 88 and 32 m{sup 2}/g, respectively. TEM and VSM results showed that the nanocomposite calcined at 700 °C has core–shell morphology and a maximum saturation magnetization of 9.47 emu g{sup −1}. - Highlights: • A one-step modified reverse microemulsion method has been used to produce hydroxyapatite-magnesium ferrite. • Nanocomposites were loaded with ibuprofen as a magnetic drug delivery system. • The drug release behavior of nanocomposites were studied at different calcination temperature.

  12. Direct synthesis and morphological characterization of gold-dendrimer nanocomposites prepared using PAMAM succinamic acid dendrimers: preliminary study of the calcification potential.

    Science.gov (United States)

    Vasile, E; Serafim, A; Petre, D; Giol, D; Dubruel, P; Iovu, H; Stancu, I C

    2014-01-01

    Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach based on the use of polyamidoamine dendrimers with succinamic acid terminal groups and dodecanediamine core. Spherical and highly crystalline nanoparticles with dimensions between 3 nm and 60 nm, and size-polydispersity depending on the synthesis conditions, have been generated. The influence of the stoichiometric ratio and the structural and architectural features of the dendrimers on the properties of the nanocomposites has been described. The self-assembling behaviour of these materials produces gold-dendrimer nanostructured porous networks with variable density, porosity, and composition. The investigations of the reaction systems, by TEM, at two postsynthesis moments, allowed to preliminary establish the control over the properties of the nanocomposite products. Furthermore, this study allowed better understanding of the mechanism of nanocomposite generation. Impressively, in the early stages of the synthesis, the organization of gold inside the dendrimer molecules has been evidenced by micrographs. Growth and ripening mechanisms further lead to nanoparticles with typical characteristics. The potential of such nanocomposite particles to induce calcification when coating a polymer substrate was also investigated.

  13. Synthesis of protocatechuic acid–zinc/aluminium–layered double hydroxide nanocomposite as an anticancer nanodelivery system

    Energy Technology Data Exchange (ETDEWEB)

    Barahuie, Farahnaz [Materials Synthesis and Characterisation Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Hussein, Mohd Zobir, E-mail: mzobir@upm.edu.my [Materials Synthesis and Characterisation Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Gani, Shafinaz Abd [Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Fakurazi, Sharida [Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia); Zainal, Zulkarnain [Materials Synthesis and Characterisation Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor (Malaysia)

    2015-01-15

    Protocatechuic acid, an active anticancer agent, has been intercalated into Zn/Al–layered double hydroxide at Zn/Al=2) using two different preparation methods, co-precipitation and ion-exchange, which are labelled as PZAE and PZAC, respectively. The release of protocatechuate from the nanocomposites occurred in a controlled manner and was fitted satisfactorily to pseudo-second order kinetics. The basal spacing of the resulting nanocomposites PZAE and PZAC was 10.2 and 11.0 Å, respectively, indicating successful intercalation of protocatechuate anions into the interlayer galleries of Zn/Al–NO{sub 3}–LDH in a monolayer arrangement with angles of 24 and 33° from the z-axis in PZAE and PZAC, respectively. The formation of nanocomposites was further confirmed by a Fourier transform infrared study. Thermogravimetric and differential thermogravimetric analyses indicated that the thermal stability of the intercalated protocatechuic acid was significantly enhanced compared to its free protocatechuic acid, and the drug content in the nanocomposites was estimated to be approximately 32.6% in PZAE and 29.2% in PZAC. Both PZAE and PZAC nanocomposites inhibit the growth of human cervical, liver and colorectal cancer cell lines and exhibit no toxic effects towards normal fibroblast 3T3 cell after 72 h of treatment. - Graphical abstract: Protocatechuate anions were arranged in monolayer mode with the angle of 24° for PZAE and 33° for PZAC from Z axis to maximize interaction between carboxylate groups and brucite-like layers. - Highlights: • Two methods gave nanocomposites with slightly different physico-chemical properties. • PZAE and PZAC have the potential to be used as a controlled release formulation. • The thermal stability of PA is markedly enhanced upon the intercalation process. • Higher cancer cell growth inhibition for PZAE and PZAC nanocomposites than for PA.

  14. One-pot synthesis of a Ni–Mn3O4 nanocomposite for supercapacitors

    International Nuclear Information System (INIS)

    Xu, Guo-rong; Shi, Jin-jin; Dong, Wen-hao; Wen, Ya; Min, Xiang-ping; Tang, An-ping

    2015-01-01

    Highlights: • Ni–Mn 3 O 4 nanocomposites have been synthesized simply. • Mn 3 O 4 particles were deposited on surface of Ni particles with OH functional groups. • Ni–Mn 3 O 4 composites could be quickly conditioned to birnessite-type MnO 2 . • A specific capacitance of 230 F g −1 was obtained for Ni (17.3%)–Mn 3 O 4 nanocomposite. - Abstract: Ni–Mn 3 O 4 nanocomposite has been prepared successfully by chemical oxidation in an alkaline solution of Mn 2+ on the surface of Ni nanoparticles with OH functional groups using one-pot method. The obtained Ni–Mn 3 O 4 nanocomposite was characterized using a scanning electron microscope (SEM), a transmission electron microscope (TEM), X-ray diffraction (XRD) analysis and various electrochemical techniques, such as cyclic voltammetry (CV), galvanostatic charge/discharge (GC/D) and electrochemical impedance spectroscopy (EIS). The average crystal sizes of Mn 3 O 4 were found to decrease linearly with increasing Ni content in the Ni–Mn 3 O 4 composite. The Ni–Mn 3 O 4 nanocomposite could be easily conditioned and inverted to birnessite-type MnO 2 . A specific capacitance of 230 F g −1 (based on pure Mn 3 O 4 ) was obtained for the Ni (17.3%)–Mn 3 O 4 nanocomposite at a current rate of 0.25 A g −1 , and 94% of the initial capacitance was retained after 1000 GC/D cycles at a current rate of 1 A g −1 . It is concluded that the Ni–Mn 3 O 4 nanocomposite is a promising electrode materials for supercapacitors

  15. Facile fabrication of palladium-ionic liquids-nitrogen-doped graphene nanocomposites as enhanced electro-catalyst for ethanol oxidation

    Science.gov (United States)

    Li, Shuwen; Yang, Honglei; Ren, Ren; Ma, Jianxin; Jin, Jun; Ma, Jiantai

    2015-10-01

    The palladium-ionic liquids-nitrogen-doped graphene nanocomposites are facile fabricated as enhanced electro-catalyst for ethanol oxidation. First, the ionic liquids functionalized nitrogen-doping graphene nanosheets (PDIL-NGS) with few layers is synthesized through a facile and effective one-pot hydrothermal method with graphene oxide as raw material, urea as reducing-doping agents and ionic liquids (ILs) derived from 3,4,9,10-perylene tetracarboxylic acid as functional molecules. The results of systematic characterization reveal that the PDIL molecules not only can functionalize NGS by π-π stacking with no affecting the nitrogen doping but also prevent the agglomeration of NGS. More importantly, the processing performance and the property of electron transfer are remarkably enhanced duo to introducing a large number of ILs groups. Then, the enhanced electrocatalytic Pd nanoparticles are successfully anchored on PDIL-NGS by a facile and surfactant-free synthetic technique. As an anode catalyst, the novel catalyst exhibits better kinetics, more superior electrocatalytic performance, higher tolerance and electrochemical stability than the other catalysts toward ethanol electrooxidation, owing to the role of PDIL molecules. Therefore, the new catalyst is believed to have the potential use for direct alcohol fuel cells in the future and the functionalized NGS is promising useful materials applied in other fields.

  16. Antifungal activity of magnetically separable Fe3O4/ZnO/AgBr nanocomposites prepared by a facile microwave-assisted method

    Directory of Open Access Journals (Sweden)

    Abolghasem Hoseinzadeh

    2016-08-01

    Full Text Available In the present work, magnetically separable Fe3O4/ZnO/AgBr nanocomposites with different weight ratios of Fe3O4 to ZnO/AgBr were prepared by a facile microwave-assisted method. The resultant samples were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, energy dispersive analysis of X-rays (EDX, and vibrating sample magnetometery (VSM. Antifungal activity of the as-prepared samples was evaluated against Fusarium graminearum and Fusarium oxysporum as two phytopathogenic fungi. Among the nanocomposites, the sample with 1:8 weight ratio of Fe3O4 to ZnO/AgBr was selected as the best nanocomposite. This nanocomposite inactivates Fusarium graminearum and Fusarium oxysporum at 120 and 60 min, respectively. Moreover, it was observed that the microwave irradiation time has considerable influence on the antifungal activity and the sample prepared by irradiation for 10 min showed the best activity. Moreover, the nanocomposite without any thermal treatment displayed the superior activity.

  17. Autoclave mediated one-pot-one-minute synthesis of AgNPs and Au-Ag nanocomposite from Melia azedarach bark extract with antimicrobial activity against food pathogens.

    Science.gov (United States)

    Pani, Alok; Lee, Joong Hee; Yun, Soon-Ii

    2016-01-01

    The increasing use of nanoparticles and nanocomposite in pharmaceutical and processed food industry have increased the demand for nontoxic and inert metallic nanostructures. Chemical and physical method of synthesis of nanostructures is most popular in industrial production, despite the fact that these methods are labor intensive and/or generate toxic effluents. There has been an increasing demand for rapid, ecofriendly and relatively cheaper synthesis of nanostructures. Here, we propose a strategy, for one-minute green synthesis of AgNPs and a one-pot one-minute green synthesis of Au-Ag nanocomposite, using Melia azedarach bark aqueous extract as reducing agent. The hydrothermal mechanism of the autoclave technology has been successfully used in this study to accelerate the nucleation and growth of nano-crystals. The study also presents high antimicrobial potential of the synthesized nano solutions against common food and water born pathogens. The multistep characterization and analysis of the synthesized nanomaterial samples, using UV-visible spectroscopy, ICP-MS, FT-IR, EDX, XRD, HR-TEM and FE-SEM, also reveal the reaction dynamics of AgNO3, AuCl3 and plant extract in synthesis of the nanoparticles and nanocomposite. The antimicrobial effectiveness of the synthesized Au-Ag nanocomposite, with high gold to silver ratio, reduces the dependency on the AgNPs, which is considered to be environmentally more toxic than the gold counterpart. We hope that this new strategy will change the present course of green synthesis. The rapidity of synthesis will also help in industrial scale green production of nanostructures using Melia azedarach.

  18. Facile synthesis of degradable and electrically conductive polysaccharide hydrogels.

    Science.gov (United States)

    Guo, Baolin; Finne-Wistrand, Anna; Albertsson, Ann-Christine

    2011-07-11

    Degradable and electrically conductive polysaccharide hydrogels (DECPHs) have been synthesized by functionalizing polysaccharide with conductive aniline oligomers. DECPHs based on chitosan (CS), aniline tetramer (AT), and glutaraldehyde were obtained by a facile one-pot reaction by using the amine group of CS and AT under mild conditions, which avoids the multistep reactions and tedious purification involved in the synthesis of degradable conductive hydrogels in our previous work. Interestingly, these one-pot hydrogels possess good film-forming properties, electrical conductivity, and a pH-sensitive swelling behavior. The chemical structure and morphology before and after swelling of the hydrogels were verified by FT-IR, NMR, and SEM. The conductivity of the hydrogels was tuned by adjusting the content of AT. The swelling ratio of the hydrogels was altered by the content of tetraaniline and cross-linker. The hydrogels underwent slow degradation in a buffer solution. The hydrogels obtained by this facile approach provide new possibilities in biomedical applications, for example, biodegradable conductive hydrogels, films, and scaffolds for cardiovascular tissue engineering and controlled drug delivery.

  19. Synthesis of well-dispersed magnetic CoFe2O4 nanoparticles in cellulose aerogels via a facile oxidative co-precipitation method.

    Science.gov (United States)

    Wan, Caichao; Li, Jian

    2015-12-10

    With the increasing emphasis on green chemistry, it is becoming more important to develop environmentally friendly matrix materials for the synthesis of nanocomposites. Cellulose aerogels with hierarchical micro/nano-scale three-dimensional network beneficial to control and guide the growth of nanoparticles, are suitable as a class of ideal green nanoparticles hosts to fabricate multifunctional nanocomposites. Herein, a facile oxidative co-precipitation method was carried out to disperse CoFe2O4 nanoparticles in the cellulose aerogels matrixes, and the cellulose aerogels were prepared from the native wheat straw based on a green NaOH/polyethylene glycol solution. The mean diameter of the well-dispersed CoFe2O4 nanoparticles in the hybrid aerogels is 98.5 nm. Besides, the hybrid aerogels exhibit strong magnetic responsiveness, which could be flexibly actuated by a small magnet. And this feature also makes this class of magnetic aerogels possibly useful as recyclable adsorbents and some magnetic devices. Meanwhile, the mild green preparation method could also be extended to fabricate other miscellaneous cellulose-based nanocomposites. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Nickel oxide/polypyrrole/silver nanocomposites with core/shell/shell structure: Synthesis, characterization and their electrochemical behaviour with antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Das, Dhaneswar; Nath, Bikash C. [Department of Chemical Sciences, Tezpur University, Tezpur 784028, Assam (India); Phukon, Pinkee [Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028, Assam (India); Saikia, Bhaskar J.; Kamrupi, Isha R. [Department of Chemical Sciences, Tezpur University, Tezpur 784028, Assam (India); Dolui, Swapan K., E-mail: dolui@tezu.ernet.in [Department of Chemical Sciences, Tezpur University, Tezpur 784028, Assam (India)

    2013-10-01

    Magnetic and conducting Nickel oxide–polypyrrole (NiO/PPy) nanoparticles with core–shell structure were prepared in the presence of Nickel oxide (NiO) in aqueous solution containing sodium dodecyl benzenesulfonate (SDBS) as a surfactant as well as dopant. A stable dispersion of silver (Ag) nanoparticles was synthesized by chemical (citrate reduction) method. NiO/PPy nanocomposites were added to the Ag colloid under stirring. Ag nanoparticles could be electrostatically attracted on the surface of NiO/PPy nanocomposites, leading to formation of NiO/PPy/Ag nanocomposites with core/shell/shell structure. The morphology, structure, particle size and composition of the products were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, cyclic voltammetry (CV) and current–voltage (I–V) analysis. The resultant nanocomposites have the good conductivity and excellent electrochemical and catalytic properties of PPy and Ag nanoparticles. Furthermore, the nanocomposites showed excellent antibacterial behaviour due to the presence of Ag nanoparticles in the composite. The thermal stability of NiO–PPy as well as NiO/PPy/Ag nanocomposites was higher than that of pristine PPy. Studies of IR spectra suggest that the increased thermal stability may be due to interactions between NiO and Ag nanoparticles with the PPy backbone. - Highlights: • NiO nanoparticles were synthesized by two step soft chemical synthesis route. • Ag nanoparticles were prepared by using citrate reduction method. • NiO/PPy nanocomposites are synthesized by chemical oxidative polymerization process. • NiO/PPy/Ag nanocomposites can be used in the water purification technology.

  1. Nickel oxide/polypyrrole/silver nanocomposites with core/shell/shell structure: Synthesis, characterization and their electrochemical behaviour with antimicrobial activities

    International Nuclear Information System (INIS)

    Das, Dhaneswar; Nath, Bikash C.; Phukon, Pinkee; Saikia, Bhaskar J.; Kamrupi, Isha R.; Dolui, Swapan K.

    2013-01-01

    Magnetic and conducting Nickel oxide–polypyrrole (NiO/PPy) nanoparticles with core–shell structure were prepared in the presence of Nickel oxide (NiO) in aqueous solution containing sodium dodecyl benzenesulfonate (SDBS) as a surfactant as well as dopant. A stable dispersion of silver (Ag) nanoparticles was synthesized by chemical (citrate reduction) method. NiO/PPy nanocomposites were added to the Ag colloid under stirring. Ag nanoparticles could be electrostatically attracted on the surface of NiO/PPy nanocomposites, leading to formation of NiO/PPy/Ag nanocomposites with core/shell/shell structure. The morphology, structure, particle size and composition of the products were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, cyclic voltammetry (CV) and current–voltage (I–V) analysis. The resultant nanocomposites have the good conductivity and excellent electrochemical and catalytic properties of PPy and Ag nanoparticles. Furthermore, the nanocomposites showed excellent antibacterial behaviour due to the presence of Ag nanoparticles in the composite. The thermal stability of NiO–PPy as well as NiO/PPy/Ag nanocomposites was higher than that of pristine PPy. Studies of IR spectra suggest that the increased thermal stability may be due to interactions between NiO and Ag nanoparticles with the PPy backbone. - Highlights: • NiO nanoparticles were synthesized by two step soft chemical synthesis route. • Ag nanoparticles were prepared by using citrate reduction method. • NiO/PPy nanocomposites are synthesized by chemical oxidative polymerization process. • NiO/PPy/Ag nanocomposites can be used in the water purification technology

  2. Synthesis of TiO(2)-PMMA nanocomposite: using methacrylic acid as a coupling agent.

    Science.gov (United States)

    Khaled, S M; Sui, Ruohong; Charpentier, Paul A; Rizkalla, Amin S

    2007-03-27

    Inorganic-polymer nanocomposites are of significant interest for emerging materials due to their improved properties and unique combination of properties. Methacrylic acid (MA), a functionalization agent that can chemically link TiO2 nanomaterials (n-TiO2) and polymer matrix, was used to modify the surface of n-TiO2 using a Ti-carboxylic coordination bond. Then, the double bond in MA was copolymerized with methyl methacrylate (MMA) to form a n-TiO2-PMMA nanocomposite. The resulting n-TiO2-PMMA nanocomposite materials were characterized by using thermal analysis, electron microscopy, and elemental analysis. The dynamic mechanical properties (Young's and shear modulus) were measured using an ultrasonic pulse technique. The electron microscopy results showed a good distribution of the nanofillers in the polymer matrix. The glass transition temperature, thermal degradation temperature, and dynamic elastic moduli of the nanocomposites were shown to increase with an increase in the weight percentage of nanofibers in the composite. The resulting nanocomposites exhibited improved elastic properties and have potential application in dental composites and bone cements.

  3. Solid-State Synthesis and Photocatalytic Activity of Polyterthiophene Derivatives/TiO2 Nanocomposites

    Directory of Open Access Journals (Sweden)

    Ruxangul Jamal

    2014-05-01

    Full Text Available Poly(3,4-propylenedioxy-2,2':5',2"-terthiophene/TiO2 and poly(3,4-(2,2-dimethylenepropylenedioxy-2,2':5',2"-terthiophene/TiO2 nanocomposites were synthesized by a simple solid-state method. Additionally, the poly(3,4-propylenedioxy thiophene/TiO2 and poly(3,4-2,2-dimethylenepropylenedioxythiophene/TiO2 nanocomposites were synthesized in a similar manner for comparison. The structure and morphology were characterized by Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis absorption spectroscopy, X-ray diffraction (XRD and transmission electron microscopy (TEM. The photocatalytic activities of the nanocomposites were examined through the degradation processes of a methylene blue (MB solution under UV light and sunlight irradiation. The results of FTIR and UV-Vis spectra showed that the composites were successfully synthesized by solid-state method and the poly(3,4-propylenedioxy-2,2':5',2"-terthiophene/TiO2 and poly(3,4-(2,2-dimethylenepropylenedioxy-2,2':5',2"-terthiophene/TiO2 nanocomposite had a higher oxidation degree and conjugation length than others. The results also indicated that the TiO2 had no effect on the crystallinity of composites, but was well embedded in the polymer matrix. Additionally, the highest degradation efficiency of 90.5% occurred in the case of the poly(3,4-propylenedioxy-2,2':5',2"-terthiophene/TiO2 nanocomposite.

  4. Sonochemical synthesis and high lithium storage properties of ordered Co/CMK-3 nanocomposites

    Science.gov (United States)

    Qiao, Hui; Xia, Zhaokang; Liu, Yanhua; Cui, Rongrong; Fei, Yaqian; Cai, Yibing; Wei, Qufu; Yao, Qingxia; Qiao, Qiquan

    2017-04-01

    A novel ordered Co/CMK-3 nanocomposite was successfully synthesized via the sonochemical method followed by carbonization process. The ordered Co/CMK-3 nanocomposite were characterized by X-ray diffraction, transmission electron microscopy and N2 adsorption-desorption analysis techniques. The lithium storage properties shows that the Co/CMK-3 nanocomposites exhibit a large reversible capacity and good cycle stability with the capacity of 720 mAh g-1 after 50 cycles at a current rate of 50 mA g-1, much higher than that of original CMK-3 electrode. The Co/CMK-3 nanocomposites also demonstrates an excellent rate capability with capacity of 479 mAh g-1 even at a current density of 1000 mA g-1 after 50 cycles. The improved lithium storage properties of ordered Co/CMK-3 nanocomposites can be attributed to the CMK-3 could restrain the aggregation of Co nanoparticles, the large surface area of the mesopores in which the Co nanoparticles are formed, as well as presence of Co which played the role of catalyst could promote the lithium storage reaction.

  5. Nano-hydroxyapatite/chitosan-starch nanocomposite as a novel bone construct: Synthesis and in vitro studies.

    Science.gov (United States)

    Shakir, Mohammad; Jolly, Reshma; Khan, Mohd Shoeb; Iram, Noor e; Khan, Haris M

    2015-09-01

    A novel ternary nanocomposite system incorporating hydroxyapatite, chitosan and starch (n-HA/CS-ST) has been synthesized by co-precipitation method at room temperature, addressing the issues of biocompatibility, mechanical strength and cytotoxicity required for bone tissue engineering. The interactions, crystallite size, surface morphology and thermal stability against n-HA/CS nanocomposite have been obtained by comparing the results of FTIR, SEM, TEM, DLS, XRD and TGA/DTA. A comparative study of bioactivity and thermal stability of n-HA/CS and n-HA/CS-ST nanocomposites revealed that the incorporation of starch as templating agent enhanced these properties in n-HA/CS-ST nanocomposite. A lower swelling rate of n-HA/CS-ST relative to n-HA/CS indicates a higher mechanical strength supportive of bone tissue ingrowths. The MTT assay on murine fibroblast L929 and human osteoblasts-like MG-63 cells and in vitro bioactivity of n-HA/CS-ST matrix referred superior non-toxic nature of n-HA/CS-ST nanocomposite and greater possibility of osteointegration in vivo respectively. Furthermore n-HA/CS-ST exhibited improved antibacterial property against both Gram-positive and Gram-negative bacteria relative to n-HA/CS. Copyright © 2015. Published by Elsevier B.V.

  6. Synthesis, characterization and dielectric properties of polynorbornadiene–clay nanocomposites by ROMP using intercalated Ruthenium catalyst

    International Nuclear Information System (INIS)

    Yalçınkaya, Esra Evrim; Balcan, Mehmet; Güler, Çetin

    2013-01-01

    Polynorbornadiene clay nanocomposites were prepared for the first time by the ring opening metathesis polymerization (ROMP) using modified montmorillonite and polynorbornadiene the latter of which is used commonly in electric–electronic industry. The Na–MMT clay was modified by a quaternary ammonium salt containing Ruthenium complex as a suitable catalyst and intercalant as well. The norbornadiene monomers were polymerized within the modified montmorillonite layers by in-situ polymerization method in different clay loading degrees. Intercalation ability of the Ru catalyst and partially exfoliated nanocomposite structure were proved by powder X-ray Diffraction (XRD) Spectroscopy and Transmission Electron Microscopy (TEM) methods. The nanocomposite materials with high thermal degradation temperature and low dielectric constant compared to the pure polynorbornadiene were obtained. The dielectric constants decreased with the increase of the clay content. - Highlights: • Polynorbornadiene–clay nanocomposites were prepared for the first time. • Ruthenium complex was assigned as both suitable catalyst and intercalant. • The norbornadiene was polymerized by in-situ polymerization method. • Exfoliation/intercalation structures were found to be related with loading degree. • PNBD–MMT nanocomposites had a higher thermal degradation temperature and lower dielectric constant

  7. Synthesis and Performance Evaluation of Pulse Electrodeposited Ni-AlN Nanocomposite Coatings

    Directory of Open Access Journals (Sweden)

    Kamran Ali

    2018-01-01

    Full Text Available This research work presents the microscopic analysis of pulse electrodeposited Ni-AlN nanocomposite coatings using SEM and AFM techniques and their performance evaluation (mechanical and electrochemical by employing nanoindentation and electrochemical methods. The Ni-AlN nanocomposite coatings were developed by pulse electrodeposition. The nickel matrix was reinforced with various amounts of AlN nanoparticles (3, 6, and 9 g/L to develop Ni-AlN nanocomposite coatings. The effect of reinforcement concentration on structure, surface morphology, and mechanical and anticorrosion properties was studied. SEM and AFM analyses indicate that Ni-AlN nanocomposite coatings have dense, homogenous, and well-defined pyramid structure containing uniformly distributed AlN particles. A decent improvement in the corrosion protection performance is also observed by the addition of AlN particles to the nickel matrix. Corrosion current was reduced from 2.15 to 1.29 μA cm−2 by increasing the AlN particles concentration from 3 to 9 g/L. It has been observed that the properties of Ni-AlN nanocomposite coating are sensitive to the concentration of AlN nanoparticles used as reinforcement.

  8. Synthesis and characterization of aluminium–alumina micro- and nano-composites by spark plasma sintering

    International Nuclear Information System (INIS)

    Dash, K.; Chaira, D.; Ray, B.C.

    2013-01-01

    Graphical abstract: The evolution of microstructure by varying the particle size of reinforcement in the matrix employing spark plasma sintering has been demonstrated here in Al–Al 2 O 3 system. An emphasis has been laid on varying the reinforcement particle size and evaluating the microstructural morphologies and their implications on mechanical performance of the composites. Nanocomposites of 0.5, 1, 3, 5, 7 volume % alumina (average size 2 O 3 micro- and nano-composites fabricated by spark plasma sintering. • Better matrix-reinforcement integrity in nanocomposites than microcomposites. • Spark plasma sintering method results in higher density and hardness values. • High density and hardness values of nanocomposites than microcomposites. • High dislocation density in spark plasma sintered Al–Al 2 O 3 composites. - Abstract: In the present study, an emphasis has been laid on evaluation of the microstructural morphologies and their implications on mechanical performance of the composites by varying the reinforcement particle size. Nanocomposites of 0.5, 1, 3, 5, 7 volume % alumina (average size 2 O 3 nancomposites respectively. Spark plasma sintering imparts enhanced densification and matrix-reinforcement proximity which have been corroborated with the experimental results

  9. Synthesis of Novel (Polymer Blend-Titanium Carbide Nanocomposites and Studying their Characterizations for Piezoelectric Applications

    Directory of Open Access Journals (Sweden)

    Ahmed Hashima

    2018-05-01

    Full Text Available Piezoelectric nanocomposites are very important for many applications as a pressure sensors. Fabrication of (polyvinyl alcohol - polyvinyl pyrrolidinone -titanium carbide nanocompos- ites and study their structural, electrical, dielectric and optical properties have been in- vestigated. The effect of adding the TiC nanoparticles on structural, electrical, dielectric and optical properties of polymeric blend has been studied. The results showed that the electrical conductivity of (PVA-PVP-TiC nanocomposites is increasing with the increase of TiC nanoparticles concentrations at room temperature. The FTIR analysis showed there is no interactions between (PVA- PVP polymer blend and TiC nanoparticles. The dielectric studies showed the dielectric constant and dielectric loss of nanocomposites increase with the increase of TiC nanoparticles concentrations and they decrease as frequency increased. The A.C electrical conductivity increases with the increase of TiC nanoparticles concentra- tions and frequency. The results of optical properties showed that the optical absorbance of (PVA- PVP polymer blend increases with the increase of TiC nanoparticles concentrations. The optical constants change with increase in TiC nanoparticles concentrations. The piezo- electric application results of (PVA-PVP-TiC nanocomposites showed that the electrical resistance of (PVA-PVP-TiC nanocomposites decreases with an increase of the pressure which make it is suitable for piezoelectric applications or pressure sensors.

  10. Synthesis and characterization of new bifunctional nanocomposites possessing upconversion and oxygen-sensing properties

    International Nuclear Information System (INIS)

    Liu Lina; Li Bin; Qin Ruifei; Zhao Haifeng; Ren Xinguang; Su Zhongmin

    2010-01-01

    A new type of bifunctional nanocomposites for biomedical applications, upconversion NaY F 4 :Y b 3+ , Tm 3+ nanoparticles coated with Ru(II) complex chemically doped SiO 2 , has been developed by combining the useful functions of upconversion and oxygen-sensing properties into one nanoparticle. NaY F 4 :Y b 3+ , Tm 3+ nanoparticles were successfully coated with an Ru(II) complex doped SiO 2 shell with a thickness of ∼ 30 nm, and the surface of the SiO 2 was functionalized with amines. The obtained nanocomposites exhibited bright blue upconversion emission, and the luminescent emission intensity of the Ru(II) complex in the nanocomposites was sensitive to oxygen. Compared with the simple mixture of Ru(II) complex and SiO 2 , the core-shell nanocomposites showed better linearity between emission intensity of Ru(II) complex and oxygen concentrations. These bifunctional nanocomposites may find applications in biochemical and biomedical fields, such as biolabels and optical oxygen sensors, which can measure the oxygen concentrations in biological fluids.

  11. Aloe vera mediated hydrothermal synthesis of reduced graphene oxide decorated ZnO nanocomposite: Luminescence and antioxidant properties

    Science.gov (United States)

    Kavyashree, D.; Nagabhushana, H.; Ananda Kumari, R.; Basavaraj, R. B.; Suresh, D.; Daruka Prasad, B.; Sharma, S. C.

    2016-05-01

    A zinc oxide/reduced graphene oxide (ZnO/rGO) nanocomposite was fabricated by facile hydrothermal route using Aloe vera gel as surfactant. The PL emission spectrum of the ZnO/rGO composite consists of four peaks at around 380, 394, 449 and 465nm. The PL intensity is found to diminish in ZnO-rGO composites rather than in pure ZnO, which was attributed to electron transfer from ZnO to rGO. A single intense glow curve was recorded in rGo-ZnO for a dose range of 1-8kGy. The TL response curve of rGO-ZnO is found to be a simple glow curve structure, linear dependence over a dose range of 1-8kGy. The obtained ZnO/rGO composite could provide a facile and eco-friendly method for the development of graphene-based nanocomposites with promising applications in radiation dosimetry and antioxidant activities.

  12. Synthesis and Characterization of Nanoparticles and Nanocomposite of ZnO and MgO by Sonochemical Method and their Application for Zinc Polycarboxylate Dental Cement Preparation

    OpenAIRE

    Mohammad Ali Karimi; Saeed Haghdar Roozbahani; Reza Asadiniya; Abdolhamid Hatefi-Mehrjardi; Mohammad Hossein Mashhadizadeh; Reza Behjatmanesh-Ardakani; Mohammad Mazloum-Ardakani; Hadi Kargar; Seyed Mojtaba Zebarjad

    2011-01-01

    This paper discusses the synthesis of nanoparticles of ZnO and MgO and ZnO/MgO nanocomposite by the sonochemical method. At first, nanoparticles were synthesized by the reaction of Zn(CHCOO3)2 and Mg(CHCOO3)2 with tetramethylammonium hydroxide (TMAH) in the presence of polyvinyl pyrrolidone (PVP) and constant frequency ultrasonic waves (sonochemical method). Then, ZnO/MgO nanocomposite was prepared through reaction of magnesium acetate with TMAH in the presence of ZnO nanoparticles and PVP as...

  13. Synthesis of Au NP@MoS2 Quantum Dots Core@Shell Nanocomposites for SERS Bio-Analysis and Label-Free Bio-Imaging

    Directory of Open Access Journals (Sweden)

    Xixi Fei

    2017-06-01

    Full Text Available In this work, we report a facile method using MoS2 quantum dots (QDs as reducers to directly react with HAuCl4 for the synthesis of Au nanoparticle@MoS2 quantum dots (Au NP@MoS2 QDs core@shell nanocomposites with an ultrathin shell of ca. 1 nm. The prepared Au NP@MoS2 QDs reveal high surface enhanced Raman scattering (SERS performance regarding sensitivity as well as the satisfactory SERS reproducibility and stability. The limit of detection of the hybrids for crystal violet can reach 0.5 nM with a reasonable linear response range from 0.5 μM to 0.5 nM (R2 ≈ 0.974. Furthermore, the near-infrared SERS detection based on Au NP@MoS2 QDs in living cells is achieved with distinct Raman signals which are clearly assigned to the various cellular components. Meanwhile, the distinguishable SERS images are acquired from the 4T1 cells with the incubation of Au NP@MoS2 QDs. Consequently, the straightforward strategy of using Au NP@MoS2 QDs exhibits great potential as a superior SERS substrate for chemical and biological detection as well as bio-imaging.

  14. Synthesis and Thermal and Photo Behaviors of New Polyamide/Organocaly Nanocomposites Containing Para Phenylenediacrylic Moiety

    Science.gov (United States)

    Faghihi, Khalil; Soleimani, Masoumeh; Shabanian, Meisam; Abootalebi, Ashraf Sadat

    2011-06-01

    New type of aromatic polyamide/montmorillonite nanocomposites were produced using solution process in N-methyl-2-pyrolidone. Amide chains were synthesized from 4,4'-diaminodiphenyl sulfone and p-phenylenediacrylic acid in N-methyl-2-pyrolidone. The resulting nanocomposite films containing 5-15 mass % of organoclay were characterized for FT-IR, scanning electronmicroscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), optical transparency and water absorption measurements. The distribution of organoclay and nanostructure of the composites were investigated by (XRD) and SEM analyses. Thermogravimetric analysis indicated an increase in thermal stability of nanocomposites as compared to pristine polyamide. The percentage optical transparency and water absorption of these hybrids was found to be much reduced upon the addition of modified layered silicate indicating decreased permeability.

  15. Synthesis, characterization, biocompatibility of hydroxyapatite-natural polymers nanocomposites for dentistry applications.

    Science.gov (United States)

    Chung, Jin-Hwan; Kim, Young Kyung; Kim, Kyo-Han; Kwon, Tae-Yub; Vaezmomeni, Seyede Ziba; Samiei, Mohammad; Aghazadeh, Marzyeh; Davaran, Soodabeh; Mahkam, Mehrdad; Asadi, Ghale; Akbarzadeh, Abolfazl

    2016-01-01

    Hydroxyapatite (HA), the main mineral component of bones and teeth, was synthesized by using the reaction between calcium nitrate tetrahydrate Ca(NO3)2∙4H2O and diammonium hydrogen phosphate (NH4)2HPO4 (DAHP) with a chemical precipitation method. The objective of this study is to utilize novel inorganic-organic nanocomposites for biomedical applications. HA is an inorganic component (75% w) and chitosan, alginate and albumin (Egg white) are organic components of nanocomposites (25% w). Nanocomposites were prepared in deionized water solutions, at room temperature, using a mechanical and magnetic stirrer for 48 h. The microstructure and morphology of sintered n-HAP were tested at different preheating temperature and laser sintering speed with scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR).

  16. Synthesis of Co/MFe(2)O(4) (M = Fe, Mn) Core/Shell Nanocomposite Particles.

    Science.gov (United States)

    Peng, Sheng; Xie, Jin; Sun, Shouheng

    2008-01-01

    Monodispersed cobalt nanoparticles (NPs) with controllable size (8-14 nm) have been synthesized using thermal decomposition of dicobaltoctacarbonyl in organic solvent. The as-synthesized high magnetic moment (125 emu/g) Co NPs are dispersible in various organic solvents, and can be easily transferred into aqueous phase by surface modification using phospholipids. However, the modified hydrophilic Co NPs are not stable as they are quickly oxidized, agglomerated in buffer. Co NPs are stabilized by coating the MFe(2)O(4) (M = Fe, Mn) ferrite shell. Core/shell structured bimagnetic Co/MFe(2)O(4) nanocomposites are prepared with tunable shell thickness (1-5 nm). The Co/MFe(2)O(4) nanocomposites retain the high magnetic moment density from the Co core, while gaining chemical and magnetic stability from the ferrite shell. Comparing to Co NPs, the nanocomposites show much enhanced stability in buffer solution at elevated temperatures, making them promising for biomedical applications.

  17. Synthesis of Co/Co3O4 Nanocomposite Particles Relevant to Magnetic Field Processing

    DEFF Research Database (Denmark)

    Srivastava, A.K.; Madhavi, S.; Menon, Mohan

    2010-01-01

    Co/Co3O4 nanocomposite particles of various morphologies were synthesized by the reverse micelle technique. Equiaxed, rod and faceted crystals with rectangular, pentagonal and hexagonal cross sections were observed. Annealing resulted in the formation of a composite of cobalt oxide (Co3O4) and fc...... cobalt (Co). Removal of boron residues from the final product was established by surface characterization. Magnetic moment of these nanocomposite particles is relevant to magnetic field processing.......Co/Co3O4 nanocomposite particles of various morphologies were synthesized by the reverse micelle technique. Equiaxed, rod and faceted crystals with rectangular, pentagonal and hexagonal cross sections were observed. Annealing resulted in the formation of a composite of cobalt oxide (Co3O4) and fcc...

  18. A comparative approach to synthesis and sintering of alumina/yttria nanocomposite powders using different precipitants

    Energy Technology Data Exchange (ETDEWEB)

    Kafili, G. [Department of Nanotechnology Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan, 81746-73441 (Iran, Islamic Republic of); Movahedi, B., E-mail: b.movahedi@ast.ui.ac.ir [Department of Nanotechnology Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan, 81746-73441 (Iran, Islamic Republic of); Milani, M. [Faculty of Advanced Materials and Renewable Energy Research Center, Tehran (Iran, Islamic Republic of)

    2016-11-01

    Alumina/yttria nanocomposite powder as an yttrium aluminum garnet (YAG) precursor was synthesized via partial wet route using urea and ammonium hydrogen carbonate (AHC) as precipitants, respectively. The products were characterized using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and energy dispersive spectroscopy. The use of urea produced very tiny spherical Y-compounds with chemical composition of Y{sub 2}(CO{sub 3}){sub 3}·nH{sub 2}O, which were attracted to the surface of alumina nanoparticles and consequently, a core-shell structure was obtained. The use of ammonium hydrogen carbonate produced sheets of Y-compounds with chemical composition of Y(OH)CO{sub 3} covering the alumina nanoparticles. A fine-grained YAG ceramic (about 500 nm), presenting a non-negligible transparency (45% RIT at IR range) was obtained by the spark plasma sintering (SPS) of alumina-yttria nanocomposite synthesized in the urea system. This amount of transmission was obtained by only the sintering of the powder specimen without any colloidal forming process before sintering or adding any sintering aids or dopant elements. However, by spark plasma sintering of alumina-yttria nanocomposite powder synthesized in AHC system, an opaque YAG ceramic with an average grain size of 1.2 μm was obtained. - Highlights: • Urea proved to be an appropriate precipitant for obtaining a core-shell alumina/yttria nanocomposite. • Alumina/yttria nanocomposite powders with more appropriate morphology and highly sinterability. • A fine-grained YAG ceramic was obtained by SPS of alumina-yttria nanocomposite.

  19. Synthesis of MnO{sub 2}/short multi-walled carbon nanotube nanocomposite for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinhui; Wang, Yanhui; Zang, Jianbing, E-mail: diamondzjb@163.com; Xin, Guoxiang; Ji, Huiying; Yuan, Yungang

    2014-01-15

    Multi-walled carbon nanotubes (MWNTs) were selectively etched in molten nitrate to produce short MWNTs (s-MWNTs). MnO{sub 2}/s-MWNT nanocomposite was synthesized by a reduction of potassium permanganate under microwave irradiation. For comparative purpose, MnO{sub 2}/MWNT nanocomposite was also synthesized and investigated for its physical and electrochemical performance. Uniform and conformal MnO{sub 2} coatings were more easily formed on the surfaces of individual s-MWNTs. MnO{sub 2}/s-MWNT nanocomposite estimated by cyclic voltammetry (CV) in 0.5 M Na{sub 2}SO{sub 4} aqueous solution had the specific capacitance as high as 392.1 F g{sup −1} at 2 mV s{sup −1}. This value was more than 48.9% larger than MnO{sub 2}/s-MWNT nanocomposite. In addition, MnO{sub 2}/s-MWNT nanocomposite was also examined by repeating the CV test at a scan rate of 50 mV s{sup −1}, exhibiting an excellent cycling stability along with 99.2% specific capacitance retained after 1000 cycles. Therefore, MnO{sub 2}/s-MWNT nanocomposite is a promising electrode material in the supercapacitors. - Highlights: • Multi-walled carbon nanotubes are etched in molten nitrate to produce short MWNTs. • S-MWNTs can form more stable suspensions than did the pristine MWNTs. • Nano-scaled MnO{sub 2} is more effectively dispersed on the surface of the s-MWNTs. • This microstructure promotes the electrical conductivity of the electrode. • The electrode exhibits high specific capacitance and a cycle stability.

  20. Synthesis of hybrid organic–inorganic nanocomposite materials based on CdS nanocrystals for energy conversion applications

    International Nuclear Information System (INIS)

    Laera, A. M.; Resta, V.; Ferrara, M. C.; Schioppa, M.; Piscopiello, E.; Tapfer, L.

    2011-01-01

    Efficient solar energy conversion is strongly related to the development of new materials with enhanced functional properties. In this context, a wide variety of inorganic, organic, or hybrid nanostructured materials have been investigated. In particular, in hybrid organic–inorganic nanocomposites are combined the convenient properties of organic polymers, such as easy manipulation and mechanical flexibility, and the unique size-dependent properties of nanocrystals (NCs). However, applications of hybrid nanocomposites in photovoltaic devices require a homogeneous and highly dense dispersion of NCs in polymer in order to guarantee not only an efficient charge separation, but also an efficient transport of the carriers to the electrodes without recombination. In previous works, we demonstrated that cadmium thiolate complexes are suitable precursors for the in situ synthesis of nanocrystalline CdS. Here, we show that the soluble [Cd(SBz) 2 ] 2 ·(1-methyl imidazole) complex can be efficiently annealed in a conjugated polymer obtaining a nanocomposite with a regular and compact network of NCs. The proposed synthetic strategies require annealing temperatures well below 200 °C and short time for the thermal treatment, i.e., less than 30 min. We also show that the same complex can be used to synthesize CdS NCs in mesoporous TiO 2 . The adsorption of cadmium thiolate molecule in TiO 2 matrix can be obtained by using chemical bath deposition technique and subsequent thermal annealing. The use of NCs, quantum dots, as sensitizers of TiO 2 matrices represents a very promising alternative to common dye-sensitized solar cells and an interesting solution for heterogeneous photocatalysis.

  1. Synthesis and characterization of polypropiolate sodium (PPNa)-Fe3O4 nanocomposite

    International Nuclear Information System (INIS)

    Bahceci, S.; Unal, B.; Baykal, A.; Soezeri, H.; Karaoglu, E.; Esat, B.

    2011-01-01

    Highlights: · Polypropiolate sodium (PPNa)-Fe 3 O 4 nanocomposite was successfully synthesized by reflux route. · FT-IR, TGA and TEM analyses showed that the presence of PPNa onto the surface of Fe 3 O 4 NP's. · Magnetization measurements revealed that (PPNa)-Fe 3 O 4 nanocomposite has superparamagnetic properties at room temperature. · Magnetic core size, particle size and crystallite size are coinciding with each other. · It is pointed out that the a.c. conductivity of the nanocomposite studied here obeys the well-known power law of frequency in which it also varies with temperatures. - Abstract: Polypropiolate sodium (PPNa)-Fe 3 O 4 nanocomposites were successfully synthesized by the precipitation of Fe 3 O 4 in the presence of sodium polypropiolate and followed by reflux route. Structural, morphological, electrical and magnetic properties evaluation of the nanocomposite were performed by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), vibrating scanning magnetometry (VSM) and conductivity measurements. Crystalline phase was identified as magnetite with an average crystallite size of 7 ± 3 nm as estimated from X-ray line profile fitting. Particle size estimated from TEM, by log-normal fitting, is ∼9 ± 1 nm. FT-IR analysis shows that the binding of PPNa on the surface of iron oxide is through bidentate linkage of carboxyl group. TGA analysis showed the presence of 20% PPNa around 80% magnetic core (Fe 3 O 4 )...PPNa-Fe 3 O 4 nanocomposite show superparamagnetic characteristics at room temperature. It is found that the a.c. conductivity of the nanocomposites obeys the well-known power law of frequency in which it also depends on temperature. Additionally, its d.c. conductivity showed that two operating regions of the activation energy. Both real and imaginary parts of either permittivity exhibit almost the same attitudes which are the indication of

  2. Synthesis and characterization of multifunctional silica core-shell nanocomposites with magnetic and fluorescent functionalities

    International Nuclear Information System (INIS)

    Ma Zhiya; Dosev, Dosi; Nichkova, Mikaela; Dumas, Randy K.; Gee, Shirley J.; Hammock, Bruce D.; Liu Kai; Kennedy, Ian M.

    2009-01-01

    Multifunctional core-shell nanocomposites with a magnetic core and a silica shell doped with lanthanide chelate have been prepared by a simple method. First, citric acid-modified magnetite nanoparticles were synthesized by a chemical coprecipitation method. Then the magnetite nanoparticles were coated with silica shells doped with terbium (Tb 3+ ) complex by a modified Stoeber method based on hydrolyzing and condensation of tetraethyl orthosilicate (TEOS) and a silane precursor. These multifunctional nanocomposites are potentially useful in a variety of biological areas such as bio-imaging, bio-labeling and bioassays because they can be simultaneously manipulated with an external magnetic field and exhibit unique phosphorescence properties.

  3. Facile synthesis of poly (p-phenylenediamine)/MWCNT ...

    Indian Academy of Sciences (India)

    Poly(-phenylenediamine) (PPD)/carboxylic acid-functionalized multiwalled carbon nanotubes (-MWCNTs) nanocomposites were prepared by chemical oxidative polymerization using potassium persulfate (K2S2O8) as an oxidant. Field-emission scanning electron microscopy (FE–SEM) and field-emission transmission ...

  4. Facile synthesis of poly(p-phenylenediamine)/MWCNT ...

    Indian Academy of Sciences (India)

    FT–IR analysis provided an evidence for the formation of nanocomposites. The thermal stability of ... (>97%) from Tokyo Chemical Industry and potassium per- sulfate (KPS) (>99%) from .... its expanded view (figure 3d). The core is a nanotube ...

  5. Synthesis and Characterization of CdS/TiO2-Montmorillonite Nanocomposite with Enhanced Visible-Light Absorption

    Directory of Open Access Journals (Sweden)

    Feng-shan Zhou

    2014-01-01

    Full Text Available Sodium montmorillonite (MMT was chosen as the carrier; a serial of CdS/TiO2-MMT nanocomposites with enhanced visible-light absorption ability was prepared by hydrothermal synthesis method combination with semiconductor compound modification method. The samples are characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, and ultraviolet visible (UV-Vis spectroscopy; the results showed that TiO2 and CdS nanoparticles were loaded on the surface of montmorillonite uniformly. N2 adsorption-desorption experiment showed that the specific surface area of TiO2/montmorillonite nanocomposite made by this method can reach 200 m2/g and pore-size distribution was from 4 to 6 nm; UV-Vis showed that the recombination of CdS and TiO2 enhanced visible-light absorption ability of samples of TiO2/montmorillonite and visible-light absorption ability increase with the increased of the adsorption of CdS.

  6. In situ self-sacrificed template synthesis of vanadium nitride/nitrogen-doped graphene nanocomposites for electrochemical capacitors.

    Science.gov (United States)

    Liu, Hong-Hui; Zhang, Hong-Ling; Xu, Hong-Bin; Lou, Tai-Ping; Sui, Zhi-Tong; Zhang, Yi

    2018-03-15

    Vanadium nitride and graphene have been widely used as pseudo-capacitive and electric double-layer capacitor electrode materials for electrochemical capacitors, respectively. However, the poor cycling stability of vanadium nitride and the low capacitance of graphene impeded their practical applications. Herein, we demonstrated an in situ self-sacrificed template method for the synthesis of vanadium nitride/nitrogen-doped graphene (VN/NGr) nanocomposites by the pyrolysis of a mixture of dicyandiamide, glucose, and NH 4 VO 3 . Vanadium nitride nanoparticles of the size in the range of 2 to 7 nm were uniformly embedded into the nitrogen-doped graphene skeleton. Furthermore, the VN/NGr nanocomposites with a high specific surface area and pore volume showed a high specific capacitance of 255 F g -1 at 10 mV s -1 , and an excellent cycling stability (94% capacitance retention after 2000 cycles). The excellent capacitive properties were ascribed to the excellent conductivity of nitrogen-doped graphene, high surface area, high pore volume, and the synergistic effect between vanadium nitride and nitrogen-doped graphene.

  7. Nanocomposite Based on Functionalized Gold Nanoparticles and Sulfonated Poly(ether ether ketone Membranes: Synthesis and Characterization

    Directory of Open Access Journals (Sweden)

    Iole Venditti

    2017-03-01

    Full Text Available Gold nanoparticles, capped by 3-mercapto propane sulfonate (Au-3MPS, were synthesized inside a swollen sulfonated poly(ether ether ketone membrane (sPEEK. The formation of the Au-3MPS nanoparticles in the swollen sPEEK membrane was observed by spectroscopic and microscopic techniques. The nanocomposite containing the gold nanoparticles grown in the sPEEK membrane, showed the plasmon resonance λmax at about 520 nm, which remained stable over a testing period of three months. The size distribution of the nanoparticles was assessed, and the sPEEK membrane roughness, both before and after the synthesis of nanoparticles, was studied by AFM. The XPS measurements confirm Au-3MPS formation in the sPEEK membrane. Moreover, AFM experiments recorded in fluid allowed the production of images of the Au-3MPS@sPEEK composite in water at different pH levels, achieving a better understanding of the membrane behavior in a water environment; the dynamic hydration process of the Au-3MPS@sPEEK membrane was investigated. These preliminary results suggest that the newly developed nanocomposite membranes could be promising materials for fuel cell applications.

  8. Facile fabrication of HDPE-g-MA/nanodiamond nanocomposites via one-step reactive blending.

    Science.gov (United States)

    Song, Ping'an; Yu, Youming; Wu, Qiang; Fu, Shenyuan

    2012-06-29

    In this letter, nanocomposites based on maleic anhydride grafted high density polyethylene (HDPE-g-MA) and amine-functionalized nanodiamond (ND) were fabricated via one-step reactive melt-blending, generating a homogeneous dispersion of ND, as evidenced by transmission electron microscope observations. Thermal analysis results suggest that addition of ND does not affect significantly thermal stability of polymer matrix in nitrogen. However, it was interestingly found that incorporating pure ND decreases the thermal oxidation degradation stability temperature, but blending amino-functionalized ND via reactive processing significantly enhances it of HDPE in air condition. Most importantly, cone tests revealed that both ND additives and reactive blending greatly reduce the heat release rate of HDPE. The results suggest that ND has a potential application as flame retardant alternative for polymers. Tensile results show that adding ND considerably enhances Young's modulus, and reactive blending leads to further improvement in Young's modulus while hardly reducing the elongation at break of HDPE.

  9. Facile synthesis of high strength hot-water wood extract films with oxygen-barrier performance

    Science.gov (United States)

    Chen, Ge-Gu; Fu, Gen-Que; Wang, Xiao-Jun; Gong, Xiao-Dong; Niu, Ya-Shuai; Peng, Feng; Yao, Chun-Li; Sun, Run-Cang

    2017-01-01

    Biobased nanocomposite films for food packaging with high mechanical strength and good oxygen-barrier performance were developed using a hot-water wood extract (HWE). In this work, a facile approach to produce HWE/montmorillonite (MMT) based nanocomposite films with excellent physical properties is described. The focus of this study was to determine the effects of the MMT content on the structure and mechanical properties of nanocomposites and the effects of carboxymethyl cellulose (CMC) on the physical properties of the HWE-MMT films. The experimental results suggested that the intercalation of HWE and CMC in montmorillonite could produce compact, robust films with a nacre-like structure and multifunctional characteristics. This results of this study showed that the mechanical properties of the film designated FCMC0.05 (91.5 MPa) were dramatically enhanced because the proportion of HWE, MMT and CMC was 1:1.5:0.05. In addition, the optimized films exhibited an oxygen permeability below 2.0 cm3 μm/day·m2·kPa, as well as good thermal stability due to the small amount of CMC. These results provide a comprehensive understanding for further development of high-performance nanocomposites which are based on natural polymers (HWE) and assembled layered clays (MMT). These films offer great potential in the field of sustainable packaging.

  10. Synthesis of polymer/inorganic nanocomposite films using highly porous inorganic scaffolds.

    Science.gov (United States)

    Zhang, Huanjun; Popp, Matthias; Hartwig, Andreas; Mädler, Lutz

    2012-04-07

    Polymeric/inorganic nanocomposite films have been fabricated through a combination of flame-spray-pyrolysis (FSP) made inorganic scaffold and surface initiated polymerization of cyanoacrylate. The highly porous structure of pristine SnO(2) films allows the uptake of cyanoacrylate and the polymerization is surface initiated by the water adsorbed onto the SnO(2) surface. Scanning electron microscopy study reveals a nonlinear increase in the composite particle size and the film thickness with polymerization time. The structural change is rather homogeneous throughout the whole layer. The composite is formed mainly by an increase of the particle size and not by just filling the existing pores. High-resolution transmission electron microscopy imaging shows SnO(2) nanoparticles embedded in the polymeric matrix, constituting the nanocomposite material. Thermogravimetric analysis indicates that the porosity of the nanocomposite films decreases from 98% to 75%, resulting in a significant enhancement of the hardness of the films. DC conductivity measurements conducted in situ on the nanocomposite layer suggest a gradual increase in the layer resistance, pointing to a loss of connectivity between the SnO(2) primary particles as the polymerization proceeds. This journal is © The Royal Society of Chemistry 2012

  11. Synthesis of NiO@MnO{sub 2} core/shell nanocomposites for supercapacitor application

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junjiao; Huang, Ying, E-mail: chenjunjiao001@163.com; Li, Chao; Chen, Xuefang; Zhang, Xiang

    2016-01-01

    Graphical abstract: - Highlights: • MnO{sub 2} nanosheets were grown on the surface of porous NiO microtube. • The NiO@MnO{sub 2} nanocomposite exhibits excellent cycle performance. • The nanocomposite exhibits specific capacitance of 266.7 F g{sup −1} at 0.5 A g{sup −1}. - Abstract: In this work, NiO@MnO{sub 2} core/shell nanocomposites were fabricated by a two-step method. The morphology and structure of the nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction analysis and thermal gravity analysis. In addition, the supercapacitive performances were examined by cyclic voltammogram (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS). The electrochemical results indicate that the composite exhibits a specific capacitance of 266.7 F g{sup −1} at 0.5 A g{sup −1} and excellent cycling stability (81.7% retention after 2000 cycles at 1 A g{sup −1}). Therefore, this wok offers meaningful reference for supercpacitor applications in the future.

  12. Synthesis of highly monodispersed Ga-soc-MOF hollow cubes, colloidosomes and nanocomposites

    KAUST Repository

    Cai, Xuechao

    2016-07-06

    Ga-soc-MOF hollow cubes with an average size of about 300 nm were prepared by a polyvinylpyrrolidone (PVP) assisted acid etching process. Colloidosomes with sizes of around 5-10 mu m composed of single-layer tetrakaidecahedron building blocks (BBs) were synthesized for the first time. Au@Ga-soc-MOF nanocomposites with excellent catalytic properties were obtained.

  13. Synthesis of three-dimensionally ordered macroporous manganese dioxide-carbon nanocomposites for supercapacitors

    Science.gov (United States)

    Liu, Zhi; Tan, Xiuli; Gao, Xin; Song, Lihong

    2014-12-01

    In this article, we report a composite of MnO2 nanoparticles supported by three-dimensionally ordered macroporous carbon (MnO2/3DOM carbon nanocomposites) fabricated by means of a simple multi-component infiltration of three-dimensional templates. MnO2 nanoparticles of 2 nm-6 nm are observed to be highly dispersed on the 3DOM carbon scaffolds. Cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy techniques are employed to assess the properties of these nanocomposites for use in supercapacitors. The results demonstrate that MnO2 can be effectively utilized with assistance of the 3DOM carbon in the electrode. The specific capacitance of the nanocomposite electrode can reach as high as 347 F g-1 at a current density of 0.5 A g-1. Moreover, the electrode exhibit excellent charge/discharge rate and good cycling stability, retaining over 92% of its initial charge after 5500 cycles at a current density of 2.5 A g-1. Such MnO2/3DOM carbon nanocomposite represents a promising exploring direction for enhancing the device performance of metal oxide-based electrochemical supercapacitors.

  14. Hydrothermal synthesis of graphene/nickel oxide nanocomposites used as the electrode for supercapacitors.

    Science.gov (United States)

    Zhou, Zhongnian; Ni, Haifang; Fan, Li-Zhen

    2014-07-01

    Graphene (GR)-based nanocomposites with different mass ratios of NiO and GR are prepared via hydrothermal method using Ni(NO3)2 as the origin of nickel and urea as the hydrolysis-controlling agent. The morphology and electrochemical performance of the GR/NiO nanocomposites are closely associated with the mass ratios of GR to NiO. The chemical composition and morphology of the composites together with the pure GR and NiO are characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). It is found that the GR sheets and NiO particles form uniform nanocomposites with the NiO particles absorbed on the GR surface. A specific capacitance of 384 F g(-1) at a current density of 0.1 A g(-1) is achieved when the coating amount of NiO is up to 74 wt%. In addition, the attenuation of the specific capacitance is less than 6% after 500 cycles, indicating such nanocomposite has excellent cycling performance.

  15. Synthesis of highly monodispersed Ga-soc-MOF hollow cubes, colloidosomes and nanocomposites

    KAUST Repository

    Cai, Xuechao; Deng, Xiaoran; Xie, Zhongxi; Bao, Shouxin; Shi, Yanshu; Lin, Jun; Pang, Maolin; Eddaoudi, Mohamed

    2016-01-01

    Ga-soc-MOF hollow cubes with an average size of about 300 nm were prepared by a polyvinylpyrrolidone (PVP) assisted acid etching process. Colloidosomes with sizes of around 5-10 mu m composed of single-layer tetrakaidecahedron building blocks (BBs) were synthesized for the first time. Au@Ga-soc-MOF nanocomposites with excellent catalytic properties were obtained.

  16. Synthesis of NiO@MnO_2 core/shell nanocomposites for supercapacitor application

    International Nuclear Information System (INIS)

    Chen, Junjiao; Huang, Ying; Li, Chao; Chen, Xuefang; Zhang, Xiang

    2016-01-01

    Graphical abstract: - Highlights: • MnO_2 nanosheets were grown on the surface of porous NiO microtube. • The NiO@MnO_2 nanocomposite exhibits excellent cycle performance. • The nanocomposite exhibits specific capacitance of 266.7 F g"−"1 at 0.5 A g"−"1. - Abstract: In this work, NiO@MnO_2 core/shell nanocomposites were fabricated by a two-step method. The morphology and structure of the nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction analysis and thermal gravity analysis. In addition, the supercapacitive performances were examined by cyclic voltammogram (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS). The electrochemical results indicate that the composite exhibits a specific capacitance of 266.7 F g"−"1 at 0.5 A g"−"1 and excellent cycling stability (81.7% retention after 2000 cycles at 1 A g"−"1). Therefore, this wok offers meaningful reference for supercpacitor applications in the future.

  17. Microwave-assisted synthesis of graphene-Prussian Blue networked nanocomposites for electrocatalysis

    DEFF Research Database (Denmark)

    Zhang, Minwei; Ulstrup, Jens; Chi, Qijin

    There has been a great deal of interest recently in Prussian blue functional graphene. Due to they displayed advantage of both Prussian blue and graphene, we presented a one-pot and green method to synthesize interlocked graphene-Prussian Blue nanocomposites. Considering that graphene oxide (GO) ...

  18. Synthesis of Poly(styrene-co-butyl acrylate/Clay Nanocomposite via In Situ AGET ATRP

    Directory of Open Access Journals (Sweden)

    laleh Ahmadian-Alam

    2012-12-01

    Full Text Available Poly(styrene-co-butyl acrylate/clay nanocomposites were synthesized via in situ atom transfer radical polymerization using activators generated by electron transfer in the presence of a montmorillonite ion-exchanged with mixed surfactants of dodecyl trimethyl ammonium bromide and vinyl trimethyl ammonium chloride. The living nature of polymerization is confrmed by occurrence of narrow molecular weight distribution of the nanocomposites in which copolymers with polydispersity index of about 1.13-1.15 were obtained. Partial exfoliation of clay layers in the copolymer matrix was demonstrated by XRD patterns and further studies of TEM images. Thermogravimetric analysis (TGA results demonstrated a slight increase in the thermal stability of nanocomposites in comparison with the neat copolymer. DSC results indicated a decrease in the glass transition temperature (Tg of nanocomposites by the addition of clay content which are attributed to low molecular weights of the copolymers and weaker interactions between polymer chains. The chemical structure and composition of copolymers was identifed by 1H NMR analysis.

  19. Polypyrrole-coated halloysite nanotube clay nanocomposite: synthesis, characterization and Cr(VI) adsorption behaviour

    CSIR Research Space (South Africa)

    Ballav, N

    2014-12-01

    Full Text Available A polypyrrole-coated halloysite nanotube nanocomposite (PPy-HNTs NC) was prepared via in situ polymerization of pyrrole (Py) in the dispersion of HNTs and assessed for the removal of toxic Cr(VI) from aqueous solutions. ATR-FTIR and XRD results...

  20. Synthesis of bio-inspired Ag–Au nanocomposite and its anti-biofilm ...

    Indian Academy of Sciences (India)

    Nanocomposite; biological method; anti-biofilm; SEM; TEM; XRD. 1. Introduction ... [13] and banana peel extract (BPE) [14] have been reported. ∗ ... gation at 10,000 rpm for 30 min and air-dried to obtain dry ... Further, 150 μl of ethanol.

  1. Hybrid titanium dioxide/PS-b-PEO block copolymer nanocomposites based on sol-gel synthesis

    International Nuclear Information System (INIS)

    Gutierrez, J; Tercjak, A; Garcia, I; Peponi, L; Mondragon, I

    2008-01-01

    The poly(styrene)-b-poly(ethylene oxide) (SEO) amphiphilic block copolymer, with two different molecular weights, has been used as a structure directing agent for generating nanocomposites of TiO 2 /SEO via the sol-gel process. SEO amphiphilic block copolymers are designed with a hydrophilic PEO-block which can interact with inorganic molecules, as well as a hydrophobic PS-block which builds the matrix. The addition of different amounts of sol-gel provokes strong variations in the self-assembled morphology of TiO 2 /SEO nanocomposites with respect to the neat block copolymer. As confirmed by atomic force microscopy (AFM), TiO 2 /PEO-block micelles get closer, forming well-ordered spherical domains, in which TiO 2 nanoparticles constitute the core surrounded by a corona of PEO-blocks. Moreover, for 20 vol% sol-gel the generated morphology changes to a hexagonally ordered structure for both block copolymers. The cylindrical structure of these nanocomposites has been confirmed by the two-dimensional Fourier transform power spectrum of the corresponding AFM height images. Affinity between titanium dioxide precursor and PEO-block of SEO allows us to generate hybrid inorganic/organic nanocomposites, which retain the optical properties of TiO 2 , as evaluated by UV-vis spectroscopy

  2. Synthesis and characteristics of Ag/Pt bimetallic nanocomposites by arc-discharge solution plasma processing.

    Science.gov (United States)

    Pootawang, Panuphong; Saito, Nagahiro; Takai, Osamu; Lee, Sang-Yul

    2012-10-05

    Arc discharge in solution, generated by applying a high voltage of unipolar pulsed dc to electrodes of Ag and Pt, was used as a method to form Ag/Pt bimetallic nanocomposites via electrode erosion by the effects of the electric arc at the cathode (Ag rod) and the sputtering at the anode (Pt rod). Ag/Pt bimetallic nanocomposites were formed as colloidal particles dispersed in solution via the reduction of hydrogen radicals generated during discharge without the addition of chemical precursor or reducing agent. At a discharge time of 30 s, the fine bimetallic nanoparticles with a mean particle size of approximately 5 nm were observed by transmission electron microscopy (TEM). With increasing discharge time, the bimetallic nanoparticle size tended to increase by forming an agglomeration. The presence of the relatively small amount of Pt dispersed in the Ag matrix could be observed by the analytical mapping mode of energy-dispersive x-ray spectroscopy and high-resolution TEM. This demonstrated that the synthesized particle was in the form of a nanocomposite. No contamination of other chemical substances was detected by x-ray photoelectron spectroscopy. Hence, solution plasma could be a clean and simple process to effectively synthesize Ag/Pt bimetallic nanocomposites and it is expected to be widely applicable in the preparation of several types of nanoparticle.

  3. Non-electrolytic synthesis of copper oxide/carbon nanocomposite by surface plasma in super-dehydrated ethanol

    Science.gov (United States)

    Kozak, Dmytro S.; Sergiienko, Ruslan A.; Shibata, Etsuro; Iizuka, Atsushi; Nakamura, Takashi

    2016-02-01

    Electrolytic processes are widely used to synthesize different nanomaterials and it does not depend on what kind of the method has been applied (wet-chemistry, sonochemistry, plasma chemistry, electrolysis and so on). Generally, the reactions in the electrolyte are considered to be reduction/oxidation (REDOX) reactions between chemical reagents or the deposition of matter on the electrodes, in line with Faraday’s law. Due to the presence of electroconductive additives in any electrolyte, the polarization effect of polar molecules conducting an electrical current disappears, when external high-strength electric field is induced. Because initially of the charge transfer always belongs of electroconductive additive and it does not depend on applied voltage. The polarization of ethanol molecules has been applied to conduct an electric current by surface plasma interaction for the synthesis of a copper oxide/carbon nanocomposite material.

  4. One-pot hydrothermal synthesis, characterization, and electrochemical properties of rGO/MnFe2O4 nanocomposites

    Science.gov (United States)

    Kotutha, Isara; Swatsitang, Ekaphan; Meewassana, Worawat; Maensiri, Santi

    2015-06-01

    In this work, a simple facile route for preparing an rGO/MnFe2O4 nanocomposite through a one-pot hydrothermal approach was demonstrated. Graphite oxide (GO) was prepared from graphite powder by a modified Hummers method. Fe(NO3)2 • 9H2O and Mn(NO3)2 • H2O were used as the precursors for the preparation of the rGO/MnFe2O4 nanocomposite. The formation of the rGO/MnFe2O4 nanocomposite was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and Rama spectroscopy (Raman). The specific surface area of the prepared composite obtained by Brunauer-Emmett-Teller (BET) analysis was lower than that of pure rGO but higher than that of pure MnFe2O4. Consequently, the electrochemical performance was investigated by using a three-electrode cell system in 6.0 M KOH. The results show that the specific capacitance was determined to be 190.3, 276.9, and 144.5 F/g at a scan rate of 10 mV/s, and 194.9, 274.6, and 134.4 F/g at a current density of 5.0 A/g for rGO, rGO/(5 mmol) MnFe2O4, and rGO/(10 mmol) MnFe2O4, respectively. These results suggest that the composite of MnFe2O4 nanoparticles on an rGO nanosheet can improve the capacitive behavior of the fabricated electrode, but the electrochemical properties are reduced when the MnFe2O4 concentration ratio is high.

  5. Facile synthesis of chondroitin sulfate-stabilized gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Li Wei, E-mail: weilixj8510@163.com [School of Science, Henan Agricultural University, No. 95 Wenhua Road, Zhengzhou, Henan 450002 (China); Li Xin; Su Hui; Zhao Shiju; Li Yanyun; Hu Jiandong [School of Science, Henan Agricultural University, No. 95 Wenhua Road, Zhengzhou, Henan 450002 (China)

    2011-02-15

    A facile and simple method for the synthesis of biocompatible gold nanoparticles (AuNPs) at room temperature has been developed by using sodium borohydride as the reducing agent and employing an inexpensive water-soluble chondroitin sulfate (CS) biopolymer as the stabilizing agent. The as-prepared AuNPs were characterized with ultraviolet-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM). Additionally, the stability of AuNPs in aqueous solution was investigated as a function of the electrolyte sodium chloride concentration. The experimental results showed that even high sodium chloride concentration (1 M) also did not destabilize the colloidal gold solution. So it could be speculated that the high stability of AuNPs should be attributed to the electrostatic repulsion and steric hindrance between the AuNPs stabilized by CS molecules, which wrapped around the surface of as-prepared AuNPs and prevented their agglomeration, and simultaneously improve biocompatibility of AuNPs as well.

  6. Facile synthesis of chondroitin sulfate-stabilized gold nanoparticles

    International Nuclear Information System (INIS)

    Li Wei; Li Xin; Su Hui; Zhao Shiju; Li Yanyun; Hu Jiandong

    2011-01-01

    A facile and simple method for the synthesis of biocompatible gold nanoparticles (AuNPs) at room temperature has been developed by using sodium borohydride as the reducing agent and employing an inexpensive water-soluble chondroitin sulfate (CS) biopolymer as the stabilizing agent. The as-prepared AuNPs were characterized with ultraviolet-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM). Additionally, the stability of AuNPs in aqueous solution was investigated as a function of the electrolyte sodium chloride concentration. The experimental results showed that even high sodium chloride concentration (1 M) also did not destabilize the colloidal gold solution. So it could be speculated that the high stability of AuNPs should be attributed to the electrostatic repulsion and steric hindrance between the AuNPs stabilized by CS molecules, which wrapped around the surface of as-prepared AuNPs and prevented their agglomeration, and simultaneously improve biocompatibility of AuNPs as well.

  7. Synthesis and characterization of new nanocomposites films using alanine-Cu-functionalized graphene oxide as nanofiller and PVA as polymeric matrix for improving of their properties

    Science.gov (United States)

    Abdolmaleki, Amir; Mallakpour, Shadpour; Karshenas, Azam

    2017-09-01

    In the synthesis of polymer-graphene nanocomposites, for improving properties of nanocomposites, two factors dispersion and strong interfacial interactions between graphene and the polymer, are essential. In the present work, poly(vinyl alcohol) PVA/GO-Cu-alanine nanocomposite films were manufactured using concentrations 0, 1, 3 and 5 wt% of GO-Cu-alanine in water solution. For this purpose, L-alanine amino acid was located on the surface and edges of GO through copper(II) ion as a coordinating function. Then, flexible PVA/GO-Cu-alanine nanocomposite films were fabricated using GO-Cu-alanine as filler and PVA as matrix. Due to the existence of affective interaction between GO-Cu-alanine and PVA matrix, the acquired PVA/GO-Cu-alanine nanocomposites demonstrated great thermal and mechanical properties. Properties of manufactured materials were characterized by Fourier transform infrared, X-ray photoelectron spectroscopies (XPS), X-ray diffraction (XRD), Thermal gravimetric analysis, elemental analysis, field emission scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX).

  8. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    International Nuclear Information System (INIS)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu

    2015-01-01

    We reported the synthesis of polystyrene@(silver–polypyrrole) (PS@(Ag–PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag + and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA) 2 ] + ) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO 3 and Py, the introduction of [Ag(TEA) 2 ] + ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag–PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA) 2 ] + ions resulted in the increase of Ag–PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag–PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 10 5  – 9×10 5  cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag–PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.Graphical Abstract

  9. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn [Ministry of Education, Beijing University of Chemical Technology, Key Laboratory of Carbon Fiber and Functional Polymer (China)

    2015-01-15

    We reported the synthesis of polystyrene@(silver–polypyrrole) (PS@(Ag–PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag{sup +} and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA){sub 2}]{sup +}) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO{sub 3} and Py, the introduction of [Ag(TEA){sub 2}]{sup +} ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag–PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA){sub 2}]{sup +} ions resulted in the increase of Ag–PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag–PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 10{sup 5} – 9×10{sup 5} cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag–PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.Graphical Abstract.

  10. One-step in situ synthesis of SnO2/graphene nanocomposites and its application as an anode material for Li-ion batteries.

    Science.gov (United States)

    Liang, Junfei; Wei, Wei; Zhong, Da; Yang, Qinglin; Li, Lidong; Guo, Lin

    2012-01-01

    A facile one-step solution-based process to in situ synthesize SnO(2)/graphene (SG) nanocomposites was developed, by using the mixture of dimethyl sulfoxide (DMSO) and H(2)O as both solvent and reactant. The reduction of graphene oxide (GO) and the in situ formation of SnO(2) nanoparticles were realized in one step. The electrochemical experiments showed the composites provided a better Li-storage performance. The method presented in this paper may provide an effective, economic, and green strategy for the preparation of metal-oxide/graphene nanocomposites. © 2011 American Chemical Society

  11. Green thermal-assisted synthesis and characterization of novel cellulose-Mg(OH)2 nanocomposite in PEG/NaOH solvent.

    Science.gov (United States)

    Ponomarev, Nikolai; Repo, Eveliina; Srivastava, Varsha; Sillanpää, Mika

    2017-11-15

    Synthesis of nanocomposites was performed using microcrystalline cellulose (MCC), MgCl 2 in PEG/NaOH solvent by a thermal-assisted method at different temperatures by varying time and the amount of MCC. Results of XRD, FTIR, and EDS mapping showed that the materials consisted of only cellulose (CL) and magnesium hydroxide (MH). According to FTIR and XRD, it was found that crystallinity of MH in cellulose nanocomposites is increased with temperature and heating time and decreased with increasing of cellulose amount. The PEG/NaOH solvent has a significant effect on cellulose and Mg(OH) 2 morphology. BET and BJH results demonstrated the effects of temperature and cellulose amount on the pore size corresponding to mesoporous materials. TG and DTG analyses showed the increased thermal stability of cellulose nanocomposites with increasing temperature. TEM and SEM analyses showed an even distribution of MH nanostructures with various morphology in the cellulose matrix. The cellulose presented as the polymer matrix in the nanocomposites. It was supposed the possible interaction between cellulose and Mg(OH) 2 . The novel synthesis method used in this study is feasible, cost-efficient and environmentally friendly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Solvothermal synthesis and good microwave absorbing properties for magnetic porous-Fe3O4/graphene nanocomposites

    Directory of Open Access Journals (Sweden)

    Xiaojun Zeng

    2017-05-01

    Full Text Available The magnetic porous-Fe3O4/graphene nanocomposites have been fabricated by a facile solvothermal method. The porous Fe3O4 nanospheres are embedded uniformly in the graphene oxide (GO sheets to form a 3D Fe3O4/GO nanocomposite network. The dielectric properties for the Fe3O4/GO composites can be greatly improved by the 7 wt% GO additions. Good impedance matching can be also obtained in these Fe3O4/GO composites, which is proved to dominate their excellent microwave absorbing properties including the minimum reflection loss (RL value of -43.7 dB at 6.8 GHz with a sample thickness of 5 mm and a broad absorption bandwidth of 5.92 GHz (below -10 dB. These porous-Fe3O4/GO composites also exhibit the good structural stability and low density, which shows their great potential application in high-performance electromagnetic microwave-absorbing materials.

  13. Green synthesis of in situ electrodeposited rGO/MnO2 nanocomposite for high energy density supercapacitors

    Science.gov (United States)

    Rusi; Majid, S. R.

    2015-11-01

    This paper presents the preparation of in situ electrodeposited rGO/MnO2 nanocomposite as a binder-free electrode for supercapacitor application. The work describes and evaluates the performance of prepared electrode via green and facile electrodeposition technique of in situ rGO/MnO2-glucose carbon nanocomposites. The carbon content in the composite electrode increased after GO and D (+) glucose solution has been added in the deposition electrolyte. This study found that a suitable concentration of D (+) glucose in the deposition electrolyte can slow down the nucleation process of MnO2 particles and lead to uniform and ultrathin nanoflakes structure. The optimize electrode exhibited low transfer resistance and resulted on excellent electrochemical performance in three electrolyte systems viz. Na2SO4, KOH and KOH/K3Fe(CN)6 redox electrolytes. The optimum energy density and power density were 1851 Whkg-1 and 68 kWkg-1 at current density of 20 Ag-1 in mixed KOH/K3Fe(CN)6 electrolyte.

  14. Design and synthesis of ternary cobalt ferrite/graphene/polyaniline hierarchical nanocomposites for high-performance supercapacitors

    Science.gov (United States)

    Xiong, Pan; Huang, Huajie; Wang, Xin

    2014-01-01

    A ternary cobalt ferrite/graphene/polyaniline nanocomposite (CGP) is designed and fabricated via a facile two-step approach: cobalt ferrite nanoparticles dispersed on graphene sheets are achieved by a hydrothermal method, followed by coating with polyaniline (PANI) through in situ polymerization process. Electrochemical measurements demonstrate that the specific capacitance of the resulting ternary hybrid (CGP) is up to 1133.3 F g-1 at a scan rate of 1 mV s-1 and 767.7 F g-1 at a current density of 0.1 A g-1 using a three-electrode system, while 716.4 F g-1 at a scan rate of 1 mV s-1 and 392.3 F g-1 at a current density of 0.1 A g-1 using a two-electrode system, which are significantly higher than those of pure CoFe2O4, graphene and PANI, or binary CoFe2O4/graphene, CoFe2O4/PANI and graphene/PANI hybrids. In addition, over 96% of the initial capacitance can be retained after repeating test for 5000 cycles, demonstrating a high cycling stability. The extraordinary electrochemical performance of the ternary CGP nanocomposite can be attributed to its well-designed nanostructure and the synergistic effects of the individual components.

  15. Facile green synthesis of graphene-Au nanorod nanoassembly for on-line extraction and sensitive stripping analysis of methyl parathion

    International Nuclear Information System (INIS)

    Zhu, Wenxin; Liu, Wei; Li, Tianbao; Yue, Xiaoyue; Liu, Tao; Zhang, Wentao; Yu, Shaoxuan; Zhang, Daohong; Wang, Jianlong

    2014-01-01

    Graphical abstract: Schematic illustration for the facile green fabrication of GN-AuNRs/GCE and its application for the extraction and electroanalysis of MP. - Highlights: • This paper described a facile green electrochemical approach to synthesize graphene-AuNRs nanocomposite. • The as-synthesized sensor shows low LOD and wide linear concentration range towards MP. • The sensor can be well used for the determination of MP in water and kiwi fruits samples. • This paper further enlarges the scope of facile green synthetic methods of GN-based hybrids. - Abstract: This paper described a facile green electrochemical approach to synthesize graphene-AuNRs nanocomposite (GN-AuNRs) onto glassy carbon electrode (GCE) for electrocatalytic analysis of methyl parathion (MP). This electrochemical synthesis of GN-AuNRs hybrid is environmentally friendly for not involving the chemical reduction of graphene oxide (GO) and facile for just on the basis of electrostatic interaction between GO and AuNRs, as well as electrochemical reduction of GO-AuNRs to GN-AuNRs. Combined the high conductivity, large surface area, good adsorption capacity towards aromatic rings and high catalytic ability of graphene with the excellent electronic properties and adsorption capacity of AuNRs, the high sensitive methyl parathion sensor was fabricated with the GN-AuNRs nanocomposite. The limit of detection (LOD) of the proposed sensor was calculated to be 0.82 ng/mL, which was lower than many previously reported enzyme or nonenzyme-based sensors. In the meantime, the linear detection range of this sensor was from 10 to 500 ng/mL and 750 to 4000 ng/mL, which was also wider than many other enzyme or enzymeless sensors. Furthermore, the facile and green electrochemical reduction strategy provided here could also be used to construct more GN-based hybrids. And the GN-based hybrid might be a new and highly efficient SPE factor, which opens new opportunities for green, facile and sensitive analysis of

  16. Radiolytic synthesis of Ag-poly(BIS-co-HEMA-co-IA) nanocomposites

    International Nuclear Information System (INIS)

    Kacarevic-Popovic, Z.; Tomic, S.; Krkljes, A.; Micic, M.; Suljovrujic, E.

    2007-01-01

    Ag-poy(BIS-co-HEMA-co-IA) nanocomposites are prepared via in situ reduction of silver salt embedded in swollen polymer gels by employing gamma irradiation. Hydrogels based on 2-hydroxyethyl methacrylate, itaconic acid and four types of poly(alkylene glycol) acrylate or methacrylate (Bisomers) were previously prepared using gamma irradiation. The nanocomposites are characterized by using UV-vis, swelling measurements and thermal analysis. Evolution of plasmon absorption detected by UV-vis spectrophotometry indicated generation of Ag nanoparticles in polymer hydrogels. Altering the structure of the hydrogels did not lead to alternation of the position of the absorption maximum. The bulk property of equilibrium swelling is dependent on the presence of the Ag nanostructures. The initial thermal stability of the polymer is slightly increased due to presence of silver as nanofiller

  17. MECHANICAL ALLOYING SYNTHESIS OF FORSTERITE-DIOPSIDE NANOCOMPOSITE POWDER FOR USING IN TISSUE ENGINEERING

    Directory of Open Access Journals (Sweden)

    Sorour Sadeghzade

    2015-03-01

    Full Text Available In present study the pure forsterite-diopside nanocomposite powder was successfully synthesized by the economical method of mechanical alloying and subsequence sintering, for the first time. The starting economical materials were talc (Mg3Si4H2O12, magnesium carbonate (MgCO3 and calcium carbonate (CaCO3 powders. The prepared powder was characterized by thermo gravimetric analysis (TGA, X-ray diffraction (XRD, and scanning electron microscopy (SEM. The results showed preparation of forsterite- diopside nanocomposite powder after 10 h mechanical alloying and sintering at 1200oC for 1 h. The powder crystallite sizes and agglomerated particle sizes were measured about 73 +/- 4 nm and 0.3 - 4 μm, respectively. Absence of enstatite that causes a reduction in mechanical and bioactivity properties of forsterite ceramic, is an important feature of produced powder.

  18. Freeze drying-assisted synthesis of Pt@reduced graphene oxide nanocomposites as excellent hydrogen sensor

    Science.gov (United States)

    Lu, Xiaojing; Song, Xinjie; Gu, Cuiping; Ren, Haibo; Sun, Yufeng; Huang, Jiarui

    2018-05-01

    Quick and efficient detection of low concentrations of hydrogen remains a challenge because of the stability of hydrogen. A sensor based on reduced oxide graphene functionalized with Pt nanoparticles is successfully fabricated using a freeze-drying method followed by heat treatment. The structure and morphology of the Pt@rGO nanocomposites are well analyzed by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The as-prepared Pt@rGO nanocomposites show excellent hydrogen gas sensing properties at a low working temperature of 50 °C. The sensitivity toward 0.5% hydrogen is 8%. The response and recovery times of the sensor exposed to 0.5% hydrogen are 63 and 104 s, respectively. The gas-sensing mechanism of Pt@rGO sensor is also discussed.

  19. Synthesis Magnesium Hydroxide Nanoparticles and Cellulose Acetate- Mg(OH2-MWCNT Nanocomposite

    Directory of Open Access Journals (Sweden)

    M. Ghorbanali

    2015-04-01

    Full Text Available Mg(OH2 nanoparticles were synthesized by a rapid microwave reaction. The effect of sodium dodecyl sulfonate (SDS as anionic surfactant and cetyl tri-methyl ammonium bromide (CTAB as cationic surfactant on the morphology of magnesium hydroxide nanostructures was investigated. Multi wall carbon nano tubes was organo-modified for better dispersion in cellulose acetate matrix. The influence of Mg(OH2 nanoparticles and modified multi wall carbon nano tubes (MWCNT on the thermal stability of the cellulose acetate (CA matrix was studied using thermo-gravimetric analysis (TGA. Nanostructures were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and Fourier transform infrared (FT-IR spectroscopy. Thermal decomposition of the nanocomposites shift towards higher temperature in the presence of Mg(OH2 nanostructures. The enhancement of thermal stability of nanocomposites is due to the endothermic decomposition of Mg(OH2 and release of water which dilutes combustible gases.

  20. Data on the synthesis processes optimization of novel β-NiS film modified CdS nanoflowers heterostructure nanocomposite for photocatalytic hydrogen evolution

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2018-02-01

    Full Text Available The data presented in this article are related to a research article entitled ‘Novel β-NiS film modified CdS nanoflowers heterostructure nanocomposite: extraordinarily highly efficient photocatalysts for hydrogen evolution’ (Zhang et al., 2018 [1]. In this article, we report original data on the synthesis processes optimization of the proposed nanocomposite on the basis of their optimum photocatalytic performance together with the comparison on the results of literatures and comparative experiments. The composition, microstructure, morphology, photocatalytic hydrogen evolution and photocatalytic stability of the corresponding samples are included in this report. The data are presented in this format in order to facilitate comparison with data from other researchers in the field and understanding the mechanism of similar catalysts. Keywords: NiS/CdS nanoflowers heterostructure, Photocatalysts, Water splitting, Hydrothermal synthesis, Optimization

  1. Fabrication and characterization of nanocomposites reinforced by carbon nanotubes - (1) synthesis of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Hseuh Hsiangming; Tai Nyanhwa; Perng Tongping [Dept. of Material Science, National Tsing-Hwa Univ., TW (China); Chyou Sander [Taiwan Power Research Inst., Taiwan Power Co., Taipei (China)

    2003-07-01

    Multi-walled carbon nanotubes (MWCNTs) produced by floating catalyst method were used for reinforcing material in polymeric nanocomposites. Five different kinds of carbon sources (benzene, toluene, xylene, cyclo-hexane, n-hexane) were used as precursors in the thermal chemical vapor deposition process. The products were collected and examined by Raman, HRTEM, and FESEM. The differences in microstructure and morphologies among these products are analyzed and discussed. (orig.)

  2. Synthesis and characterization of polyacrylonitrile-silver nanocomposites by γ-irradiation

    International Nuclear Information System (INIS)

    Liu Huarong; Ge Xuewu; Ni Yonghong; Ye Qiang; Zhang Zhicheng

    2001-01-01

    The nanocomposites of stable nanosilver particles embedded in polyacrylonitrile matrix were synthesized by γ-irradiation, in which the monomer acrylonitrile was polymerized and the silver ions were reduced simultaneously by γ-irradiation to form composites in situ. The strong interactions between silver ions with -CN groups of polyacrylonitrile are found, which were confirmed by X-ray powder diffraction, IR spectrum and absorption spectra

  3. Polystyrene/magnetite nanocomposite synthesis and characterization: investigation of magnetic and electrical properties for using as microelectromechanical systems (MEMS

    Directory of Open Access Journals (Sweden)

    Omidi Mohammad Hassan

    2017-02-01

    Full Text Available In this work, a novel polystyrene/Fe3O4 nanocomposite prepared by in-situ method is presented. Magnetic Fe3O4 nanoparticles were encapsulated by polystyrene. The FT-IR spectra confirmed polystyrene/Fe3O4 nanocomposite preparation. The electrical properties of prepared nanocomposite were investigated by cyclic voltammetry (CV. The CV analysis showed good electrical conductivity of the synthesized nanocomposite. Magnetic properties of the nanocomposite were studied by vibrating sample magnetometer (VSM. The VSM analysis confirmed magnetic properties of the nanocomposite. The morphology and the size of the synthesized nanocomposite were investigated by field emission scanning electron microscope (FESEM. According to the VSM and CV results, such nanocomposite can be used in microelectromechanical systems.

  4. In-situ synthesis and performance of titanium oxide/poly(methyl methacrylate) nanocomposites.

    Science.gov (United States)

    Bandugula, Uttam C; Clayton, L M; Harmon, J P; Kumar, Ashok

    2005-05-01

    Polymer nanocomposites have elicited extensive research efforts due to their potential to exhibit spectacular properties. They have immense potential and are befitting materials to serve as an ideal and futuristic alternative for varied applications. Poly(methyl methacrylate) (PMMA) and titanium oxide (TiO2) nanocomposites used in this study were fabricated by an in-situ free radical polymerization process. Three point bend tests were conducted with a modified universal microtribometer to evaluate fracture toughness. The results indicated that the stress intensity values increase as the concentration of titanium oxide increases up to 1 vol% and subsequently decrease at higher concentrations. Scanning electron microscopy (SEM) images of fracture surfaces afforded clues as to the possible deformation mechanism. Ultraviolet-visible spectroscopy (UV-vis) evaluated the degree of transparency of the nanocomposites. It was observed that samples became opaque as the concentration was increased beyond 0.01% volume fraction. X-ray diffraction characterized the TiO2 crystalline phase and Scherrer's equation was used to calculate the crystallite size. Among the concentrations considered the 3% volume fraction sample had the largest crystallite size. Finally, microhardness measurements further characterized the mechanical properties of the composites.

  5. Synthesis of polyaniline/SnO2 nanocomposite and its improved electrochemical performance

    International Nuclear Information System (INIS)

    Luo, Zhenyu; Zhu, Yinhai; Liu, Enhui; Hu, Tiantian; Li, Zengpeng; Liu, Tiantian; Song, Longchu

    2014-01-01

    Highlights: • Supercapacitors based on PANI/SnO 2 nanocomposite were reported. • Supercapacitors using this material gave a specific capacitance of 501 F g −1 . • Capacitance retention was 85.8% over 2000 charge–discharge cycles. - Abstract: SnO 2 was prepared by the hydrothermal route. Aniline monomer was polymerized in the suspension of SnO 2 to form inorganic–organic nanocomposite materials, in which SnO 2 particles were embedded within polyaniline (PANI). Morphological and structural characterizations of the prepared samples were carried out using scanning electron microscope; transmission electron microscope; power X-ray diffraction and Fourier transform infrared spectroscopy. Their electrochemical properties were also investigated using cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The as-prepared nanocomposites had excellent properties in the capacitance, and its specific capacitance was up to 501 F g −1 with a specific energy density of 66.8 W h kg −1 at a power density of 960.6 W kg −1 . The device fulfilled the requirement of long durability necessary for an energy storage system, since after 2000 galvanostatic charge–discharge cycles, retention of 85.8% in capacitance was observed. These results indicated that the PANI/SnO 2 had a synergistic effect of the complementary properties of both components

  6. Green Synthesis, Characterization, and Antibacterial Activity of Silver/Polystyrene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Manal A. Awad

    2015-01-01

    Full Text Available A novel, nontoxic, simple, cost-effective and ecofriendly technique was used to synthesize green silver nanoparticles (AgNPs. The AgNPs were synthesized using orange peel extract as a reducing agent for silver nitrate salt (AgNO3. The particle size distribution of AgNPs was determined by Dynamic Light Scattering (DLS. The average size of silver nanoparticles was 98.43 nm. The stable dispersion of silver nanoparticles was added slowly to polystyrene solution in toluene maintaining the temperature at 70°C. The AgNPs/polystyrene (PS nanocomposite solution was cast in a petri dish. The silver nanoparticles encapsulated within polymer chains were characterized by X-ray diffraction (XRD and Scanning Electron Microscopy (SEM equipped with Energy Dispersive Spectroscopy (EDS in addition to Transmission Electron Microscopy (TEM. The green AgNPs/PS nanocomposite film exhibited antimicrobial activity against Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae and Salmonella, and Gram-positive bacteria Staphylococcus aureus. Thus, the key findings of the work include the use of a safe and simple AgNPs/PS nanocomposite which had a marked antibacterial activity which has a potential application in food packaging.

  7. Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

    Science.gov (United States)

    Ganguly, Shreyashi; Zhou, Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

    2011-12-01

    Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2- xSb xTe 3) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2- xSb xTe 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties.

  8. Synthesis of multi-walled carbon nanotubes/{beta}-FeOOH nanocomposites with high adsorption capacity

    Energy Technology Data Exchange (ETDEWEB)

    Song Haojie, E-mail: shj6922@163.com [School of Materials Science and Engineering, Jiangsu University (China); Liu Lei [Pharmaceutic College of Henan University (China); Jia Xiaohua; Min Chunying [School of Materials Science and Engineering, Jiangsu University (China)

    2012-12-15

    A hybrid nanostructure of multi-walled carbon nanotubes (CNTs) and {beta}-ferric oxyhydroxide ({beta}-FeOOH) nanoparticles is synthesized by ultrasonic-assisted in situ hydrolysis of the precursor ferric chloride and CNTs. Characterization by X-ray diffraction, scanning electron microscopy , and transmission electron microscopy establishes the nanohybrid structure of the synthesized sample. The results revealed that the surface of CNTs was uniformly assembled by numerous {beta}-FeOOH nanoparticles and had an average diameter of 3 nm. The formation route of anchoring {beta}-FeOOH nanoparticles onto CNTs was proposed as the intercalation and adsorption of iron ions onto the wall of CNTs, followed by the nucleation and growth of {beta}-FeOOH nanoparticles. The values of remanent magnetization (M{sub r}) and coercivity (H{sub c}) of the as-synthesized CNTs/{beta}-FeOOH nanocomposites were 0.1131 emu g, and 490.824 Oe, respectively. Furthermore, CNTs/{beta}-FeOOH nanocomposites showed a very high adsorption capacity of Congo red and thus these nanocomposites can be used as good adsorbents and can be used for the removal of the dye of Congo red from the waste water system.

  9. Synthesis and Electrochemical Properties of Two-Dimensional RGO/Ti3C2Tx Nanocomposites

    Directory of Open Access Journals (Sweden)

    Changjie Shen

    2018-01-01

    Full Text Available MXene is a new type of two-dimensional layered material. Herein, a GO/Ti3C2Tx nanocomposite was prepared by a simple liquid phase method, and the obtained GO/Ti3C2Tx was transformed into RGO/Ti3C2Tx under high temperature with Ar/H2. The prepared samples were characterized using X-ray diffraction (XRD, Raman measurement, scanning electron microscopy (SEM, energy disperse spectroscopy (EDS, and X-ray photoelectron spectroscopy (XPS. As an electrode material in lithium-ion batteries, the RGO/Ti3C2Tx nanocomposite exhibited an excellent electrochemical performance and an excellent rate performance. Compared to pure Ti3C2Tx, the nanocomposite had a better reversible capacity at different current densities and had no attenuation after 200 cycles, which is one time higher than pure Ti3C2Tx. The improvement in the specific capacity was due to the excellent electrical conductivity and the unique structure of RGO, in which a charge transfer bridge was built among the Ti3C2Tx flakes. Such a bridge shortened the transmission distance of the electrons and ions and effectively controlled the restacking of the laminated materials.

  10. Synthesis, characterization and microwave characteristics of ternary nanocomposite of MWCNTs/doped Sr-hexaferrite/PANI

    Energy Technology Data Exchange (ETDEWEB)

    Seyyed Afghahi, Seyyed Salman [Department of Materials Science and Engineering, Imam Hossein University, Tehran (Iran, Islamic Republic of); Peymanfar, Reza; Javanshir, Shahrzad [Department of Chemistry, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Atassi, Yomen [Department of Applied Physics, Higher Institute for Applied Sciences and Technology, Damascus (Syrian Arab Republic); Jafarian, Mojtaba, E-mail: m.jafarian@srbiau.ac.ir [Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2017-02-01

    Substituted strontium ferrite (sub-SF) nanoparticles are prepared by a sol-gel method and added to functionalized multiwalled carbon nanotubes (MWCNTs). The ternary nanocomposite of MWCNTs/sub-SF/polyaniline (PANI) is prepared by in-situ polymerization of aniline on MWCNTs/sub-SF reaction mixture. The morphology, structure and magnetic properties of the nanocomposites are investigated by SEM, XRD, FTIR and VSM, respectively. The microwave characteristics are measured using a vector network analyzer. The XRD patterns exhibit representative diffraction peaks corresponding to hexagonal structure, and the structure of the MWCNTs is not distorted. SEM micrographs show that sub-SF nanoparticles and PANI chains are uniformly dispersed on the surface of MWCNTs. The MWCNTs/sub-SF/PANI exhibit a minimum reflection loss of −26 dB at 10 GHz with 3 GHz bandwidth and a matching thickness of 5 mm. This excellent microwave characteristic indicates the synergistic effect of the three components to enhance the impedance matching and improve the microwave absorption properties of the composite. - Highlights: • Novel ternary nanocomposite of MWCNTs/sub-SF/polyaniline (PANI) is prepared by in-situ polymerization. • The prepared single composite absorber are lightweight with 20 wt% filler content in parafin. • Composites with a combination of magnetic and dielectric fillers exhibit wider reflection loss peaks. • Composite absorber exhibit a minimum reflection loss of −26 dB at 10 GHz with 3 GHz bandwidth with a matching thickness of 5 mm.

  11. Synthesis, Characterization, and Microwave-Absorbing Properties of Polypyrrole/MnFe2O4 Nanocomposite

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Hosseini

    2012-01-01

    Full Text Available Conductive polypyrrole (PPy-manganese ferrite (MnFe2O4 nanocomposites with core-shell structure were synthesized by in situ polymerization in the presence of dodecyl benzene sulfonic acid (DBSA as the surfactant and dopant and iron chloride (FeCl3 as the oxidant. The structure and magnetic properties of manganese ferrite nanoparticles were measured by using powder X-ray diffraction (XRD and vibrating sample magnetometer (VSM, respectively. Its morphology, microstructure, and DC conductivity of the nanocomposite were characterized by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and four-wire technique, respectively. The microwave-absorbing properties of the nanocomposite powders dispersing in resin acrylic coating with the coating thickness of 1.5 mm were investigated by using vector network analyzers in the frequency range of 8–12 GHz. A minimum reflection loss of −12 dB was observed at 11.3 GHz.

  12. Controllable synthesis of functional nanocomposites: Covalently functionalize graphene sheets with biocompatible L-lysine

    International Nuclear Information System (INIS)

    Mo, Zunli; Gou, Hao; He, Jingxian; Yang, Peipei; Feng, Chao; Guo, Ruibin

    2012-01-01

    Highlights: ► The biocompatible L-lysine functionalized graphene sheets (Gs/Lys) were synthesized controllably using a novel method. ► The Gs/Lys nanocomposites are water-soluble, biocompatible and chiral. ► A chiral graphene derivative was proposed. - Abstract: In this paper a novel method to synthesize functionalize graphene sheets (Gs) by biocompatible L-lysine (Gs/Lys) is reported. The method was composed of two steps: (1) we controllably synthesized self-assembly Gs/Lys-Cu-Lys through the terminal amino of copper L-lysine (Lys-Cu-Lys) attaching to graphite oxide (GO) and then reducing. (2) Obtained the Gs/Lys by eliminating the copper ion. This method could also be used to functionalize other nanomaterials by L-lysine. The Gs/Lys nanocomposites are water-soluble, biocompatible, and above all, it is a chiral material of graphene, which is proposed by us. This novel material will be promising for more applications of graphene. The formation of Gs/Lys nanocomposites were confirmed by scanning electron microscopy (SEM), Fourier-transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermal gravimetric (TG) analysis.

  13. Synthesis of reduced graphene oxide/CeO2 nanocomposites and their photocatalytic properties

    International Nuclear Information System (INIS)

    Ji Zhenyuan; Shen Xiaoping; Li Minzhi; Zhu Guoxing; Zhou Hu; Chen Kangmin

    2013-01-01

    With a unique structure and extraordinary properties, graphene has attracted tremendous attention in the preparation of graphene-based composites for various applications. In this study, two different strategies, including in situ growth and a self-assembly approach, have been developed to load CeO 2 nanoparticles onto reduced graphene oxide (RGO) nanosheets. The microstructure and morphology of the as-synthesized RGO/CeO 2 nanocomposites were investigated by x-ray diffraction, Raman spectroscopy and transmission electron microscopy. The results reveal that CeO 2 nanoparticles with well-controlled size and a uniform distribution on RGO sheets with tunable density can be achieved through the self-assembly approach. The significantly enhanced photocatalytic activity of the RGO/CeO 2 nanocomposites in comparison with bare CeO 2 nanoparticles was revealed by the degradation of methylene blue under simulated sunlight irradiation, which can be attributed to the improved separation of electron–hole pairs and enhanced adsorption performance due to the presence of RGO. A suitable loading content of CeO 2 on RGO was found to be crucial for optimizing the photocatalytic activity of the nanocomposites. It is expected that this convenient assembly approach with high controllability can be extended to the attachment of other functional nanoparticles to RGO sheets, and the resultant RGO-supported highly dispersed nanoparticles are attractive for catalysis, sensing and power source applications. (paper)

  14. One-step synthesis of graphene-Pt nanocomposites by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Tokai, Akihiro; Okitsu, Kenji; Hori, Fuminobu; Mizukoshi, Yoshiteru; Iwase, Akihiro

    2016-01-01

    We developed a one-step gamma-ray irradiation method to synthesize nanocomposites composed of graphene and Pt nanoparticles from aqueous solution containing graphene and Pt(IV) complex ions in the presence of 2-propanol (IPA) or sodium dodecyl sulfate (SDS). It was confirmed that gamma-ray irradiation provided carbonyl groups on graphene and Pt nanoparticles formed from the radiolytic reduction of Pt(IV) complex ions were deposited onto the carbonyl modified graphene. In the presence of IPA, small Pt nanoparticles were deposited on graphene, but large Pt nanoparticles were deposited in the presence of SDS: the size of Pt nanoparticles formed was larger in the presence of SDS than IPA. Based on the results, formation and deposition mechanisms of Pt nanoparticles were proposed. - Highlights: • Graphene-Pt nanocomposites were synthesized by gamma-ray irradiation. • Reduction of Pt(IV) complex ions and oxidation of graphene occurred simultaneously. • Smaller Pt nanoparticles were formed in the presence of IPA than SDS. • Mechanism for formation of graphene-Pt nanocomposites was proposed.

  15. Bifunctional bridging linker-assisted synthesis and characterization of TiO{sub 2}/Au nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Žunič, Vojka, E-mail: vojka.zunic@ijs.si, E-mail: vojka13@gmail.com; Kurtjak, Mario; Suvorov, Danilo [Jožef Stefan Institute, Advanced Materials Department (Slovenia)

    2016-11-15

    Using a simple organic bifunctional bridging linker, titanium dioxide (TiO{sub 2}) nanoparticles were coupled with the Au nanoparticles to form TiO{sub 2}/Au nanocomposites with a variety of Au loadings. This organic bifunctional linker, meso-2,3-dimercaptosuccinic acid, contains two types of functional groups: (i) the carboxyl group, which enables binding to the TiO{sub 2}, and (ii) the thiol group, which enables binding to the Au. In addition, the organic bifunctional linker acts as a stabilizing agent to prevent the agglomeration and growth of the Au particles, resulting in the formation of highly dispersed Au nanoparticles. To form the TiO{sub 2}/Au nanocomposites in a simple way, we deliberately applied a synthetic method that simultaneously ensures: (i) the capping of the Au nanoparticles and (ii) the binding of different amounts of Au to the TiO{sub 2}. The TiO{sub 2}/Au nanocomposites formed with this method show enhanced UV and Vis photocatalytic activities when compared to the pure TiO{sub 2} nanopowders.Graphical Abstract.

  16. Synthesis and Characterization of Nanocomposites Tin Oxide-Graphene Doping Pd Using Polyol Method

    Directory of Open Access Journals (Sweden)

    Aminuddin Debataraja

    2018-05-01

    Full Text Available This paper report on polyol method for Pd doped tin oxide-graphene nanocomposite thin film. XRD result shows sharp peaks at certain 2θ value and match with tin oxide, graphene, and Pd database. FTIR result shows peak from alcohol chain for –OH strong bonded absorption (3444 cm-1, also there are aldehyde and ketone which are indicated by C=O strong absorption (1751 cm-1. Moreover, alkene is also formed for decreasing symmetry intensity C=C (1616 cm-1, while alkyne is formed at strong deformation absorption at 646 and 613 cm-1. SEM and TEM result show SnO2 particles are attached uniformly on graphene surface layer. The composition for C, O, Sn, and Pd are 33.13, 25.58, 35.35 and 5.94%, respectively. This result indicated that the good composition is formed for Pd doped SnO2-graphene nanocomposite. The nanocomposite is promising materials for toxic gas sensor application at low temperature.

  17. One-step synthesis of Ag@PANI nanocomposites and their application to detection of mercury

    International Nuclear Information System (INIS)

    Wang, Xiufang; Shen, Yuhua; Xie, Anjian; Chen, Shaohua

    2013-01-01

    The Ag@Polyaniline (PANI) core–shell nanoparticles were successfully synthesized by one-step radiation of sunlight method using silver nitrate as the oxidant for aniline without any additives or templates. The Ag@PANI core–shell nanocomposites were used as active surface enhanced Raman scattering (SERS) nanoprobes for the detection of some heavy metal ions, such as Pb 2+ , Cu 2+ Hg 2+ , Cd 2+ , and so on, which is based upon the Raman intensity response of PANI to metal ions. It turns out that the nanoprobes represent a rather high selectivity for Hg 2+ detection. It is also important that the detection limit of Hg 2+ concentration is ca. 1 × 10 −12 M in this system, due to the great sensitivity of SERS nanoprobes. The developed nanoprobes could have potential applications in highly sensitive chemical, environmental and biological analysis, as well as medical detection. - Highlights: • The Ag@PANI nanocomposites are fabricated by a simple synthetic route. • Nanocomposites are utilized directly as SERS nanosensors without being additionally functionalized. • Higher selectivity and ultrasensitive sensitivity for Hg 2+ ions detection

  18. One-pot synthesis of FePt/CNTs nanocomposites for efficient cellular imaging and cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weihong; Zheng, Xiuwen, E-mail: xwzheng1976@163.com [Linyi University, School of Chemistry & Chemical Engineering, Shandong Provincial Key Laboratory of Detection Technology for Tumor Makers (China); Li, Shulian [Linyi Tumor Hospital (China); Zhang, Wei; Wen, Xin [Linyi University, School of Chemistry & Chemical Engineering, Shandong Provincial Key Laboratory of Detection Technology for Tumor Makers (China); Yue, Ludan [Shandong Normal University (China); Wang, Jinlong [Shandong University of Technology (China)

    2015-11-15

    Here, we developed a facile route to synthesize carbon nanotube-based FePt nanocomposites (FePt/CNTs) as a potential theranostic platform in the cancer treatment. FePt/CNTs were firstly synthesized via one-pot polyol route, and then functionalized with 6-arm-polyethylene glycol-amine polymer. The average size of FePt nanoparticles (NPs) is 3–4 nm, which is dispersed on the CNT surface (ca.50–150 nm). The as-prepared FePt NPs display high cytotoxicity by highly reactive oxygen species in cancer cells. Folic acid and fluorescein isothiocyanate are assembled onto the surface of FePt/CNTs for effective targeting of folate receptor-positive cancer cells and simultaneously for the visualization of cellular uptake. Therefore, the FePt/CNTs NPs capability of simultaneously performing diagnosis, therapy, and targeting is, therefore, promising for future potential widespread application in biomedicine.

  19. One-step solution-phase synthesis of a novel RGO–Cu2O–TiO2 ternary nanocomposite with excellent cycling stability for supercapacitors

    International Nuclear Information System (INIS)

    Luo, Dongming; Li, Yaping; Liu, Jinlong; Feng, Haibo; Qian, Dong; Peng, Sanjun; Jiang, Jianbo; Liu, Youcai

    2013-01-01

    Highlights: •A novel RGO–Cu 2 O–TiO 2 was fabricated via a facile one-step solution-phase route. •The ternary nanocomposite displays excellent cycling stability for supercapacitors. •The introduction of TiO 2 to RGO–Cu 2 O can markedly improve supercapacitor properties. -- Abstract: A novel reduced graphene oxide (RGO)–Cu 2 O–TiO 2 ternary nanocomposite was successfully fabricated via a facile one-step solution-phase method. The synthesized RGO–Cu 2 O–TiO 2 nanocomposite was characterized by X-ray powder diffraction, transmission electron microscopy, atomic force microscopy and Raman spectroscopy, and its electrochemical properties as an active electrode material for supercapacitors were investigated through cyclic voltammetry (CV) and galvanostatic charge/discharge measurements in a 6 M KOH aqueous electrolyte. The obtained RGO–Cu 2 O–TiO 2 nanocomposite exhibits a specific capacitance of 80 F g −1 at a current density of 0.2 A g −1 in the 6 M KOH electrolyte, nearly twice the value of 41.4 F g −1 for the RGO–Cu 2 O nanocomposite and 2.5 times the value of 32.7 F g −1 for the RGO–TiO 2 nanocomposite. Furthermore, the specific capacitance of RGO–Cu 2 O–TiO 2 increases from 80 to 91.5 F g −1 after 1000 cycles, which can be said the least that the capacitance has not changed within error, while the specific capacitances of RGO–Cu 2 O and RGO–TiO 2 decrease from 41.4 to 34.5 F g −1 and from 32.7 to 25.2 F g −1 , respectively

  20. Preparation of highly photocatalytic active CdS/TiO{sub 2} nanocomposites by combining chemical bath deposition and microwave-assisted hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: qqhrll@163.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Key Laboratory of Composite Modified Material of Colleges in Heilongjiang Province, Qiqihar 161006 (China); Wang, Lili [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Hu, Tianyu [College of Environment and Resources, Jilin University, Changchun 130024 (China); Zhang, Wenzhi; Zhang, Xiuli; Chen, Xi [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China)

    2014-10-15

    CdS/TiO{sub 2} nanocomposites were prepared from Cd and Ti (1:1 M ratio) using cetyltrimethylammonium bromide by a two-step chemical bath deposition (CBD) and microwave-assisted hydrothermal synthesis (MAHS) method. A series of nanocomposites with different morphologies and activities were prepared by varying the reaction time in the MAHS (2, 4, and 6 h). The crystal structure, morphology, and surface physicochemical properties of the nanocomposites were characterized by X-ray diffraction, UV–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and N{sub 2} adsorption–desorption measurements. The results show that the CdS/TiO{sub 2} nanocomposites were composed of anatase TiO{sub 2} and hexagonal CdS phases with strong absorption in the visible region. The surface morphologies changed slightly with increasing microwave irradiation time, while the Brunauer–Emmett–Teller surface area increased remarkably. The photocatalytic degradation of methyl orange (MO) was investigated under UV light and simulated sunlight irradiation. The photocatalytic activity of the CdS/TiO{sub 2} (6 h) composites prepared by the MAHS method was higher than those of CdS, P25, and other CdS/TiO{sub 2} nanocomposites. The CdS/TiO{sub 2} (6 h) nanocomposites significantly affected the UV and microwave-assisted photocatalytic degradation of different dyes. To elucidate the photocatalytic reaction mechanism for the CdS/TiO{sub 2} nanocomposites, controlled experiments were performed by adding different radical scavengers. - Graphical abstract: CdS/TiO{sub 2} nanocomposites were prepared using CTAB by CBD combined with MAHS method. In addition, with increasing microwave irradiation time, the morphology of CdS/TiO{sub 2} changed from popcorn-like to wedge-like structure. - Highlights: • The CdS/TiO{sub 2} was prepared by CBD combined with MAHS two-step method under CTAB. • The morphologies of as-samples were different with the time of

  1. Tungsten-doped ZnO nanocomposite: Synthesis, characterization, and highly active photocatalyst toward dye photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Moafi, Hadi Fallah, E-mail: Fallah.m@guilan.ac.ir [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht (Iran, Islamic Republic of); Zanjanchi, Mohammad Ali; Shojaie, Abdollah Fallah [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht (Iran, Islamic Republic of)

    2013-05-15

    A series of W-doped ZnO nanocomposite with different W contents were synthesized by sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP) and BET surface area measurement. The XRD results revealed that all the W-doped samples showed a hexagonal wurtzite structure. The results of EDS and XPS revealed that W was doped into ZnO structure. The particle size of doped ZnO is much smaller as compared to that of pure ZnO. The photocatalytic activity of undoped ZnO and W-doped ZnO was evaluated by the photodegradation of methylene blue in aqueous solution. The results show that the photocatalytic activity of the W-doped ZnO is much higher than that of undoped ZnO and the optimum percentage of doped W is 4 mol%. The enhanced photocatalytic activity of the W-ZnO samples may be related to the narrowing of the band gap, increase in the charge separation efficiency, particle size reduction and increase of the surface area. Highlights: ► W-doped ZnO nanocomposites were synthesized by a sol–gel method. ► The XRD results revealed that all the materials consisting of wurtzite structure. ► The sizes of the W-ZnO nanocomposite are 5–10 nm, obtained from TEM image. ► With W doping into ZnO photoinduced charge separation rate has been enhanced. ► Photocatalytic activity of the W-ZnO is much higher than that of undoped ZnO.

  2. Tungsten-doped ZnO nanocomposite: Synthesis, characterization, and highly active photocatalyst toward dye photodegradation

    International Nuclear Information System (INIS)

    Moafi, Hadi Fallah; Zanjanchi, Mohammad Ali; Shojaie, Abdollah Fallah

    2013-01-01

    A series of W-doped ZnO nanocomposite with different W contents were synthesized by sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP) and BET surface area measurement. The XRD results revealed that all the W-doped samples showed a hexagonal wurtzite structure. The results of EDS and XPS revealed that W was doped into ZnO structure. The particle size of doped ZnO is much smaller as compared to that of pure ZnO. The photocatalytic activity of undoped ZnO and W-doped ZnO was evaluated by the photodegradation of methylene blue in aqueous solution. The results show that the photocatalytic activity of the W-doped ZnO is much higher than that of undoped ZnO and the optimum percentage of doped W is 4 mol%. The enhanced photocatalytic activity of the W-ZnO samples may be related to the narrowing of the band gap, increase in the charge separation efficiency, particle size reduction and increase of the surface area. Highlights: ► W-doped ZnO nanocomposites were synthesized by a sol–gel method. ► The XRD results revealed that all the materials consisting of wurtzite structure. ► The sizes of the W-ZnO nanocomposite are 5–10 nm, obtained from TEM image. ► With W doping into ZnO photoinduced charge separation rate has been enhanced. ► Photocatalytic activity of the W-ZnO is much higher than that of undoped ZnO

  3. Polymer-layered silicate nanocomposites by UV-radiation curing: an original synthesis

    International Nuclear Information System (INIS)

    Keller, L.; Decker, C.; Zahouily, K.; Miehe-Brendle, J.; Le Meins, J.M.

    2004-01-01

    Full text.Because of the many hopes which they raise, the nanocomposite materials are the subject of an increasing number of scientific publications. Indeed, the intimate association of a polymer matrix and silicate nano-platelets leads to the formation of materials having mechanical and barriers properties improved (fire, gas, humidity,...). A literature survey shows that these materials are generally produced by a thermal polymerization, which presents two major disadvantages: the use of organic solvents and a great consumption of energy. To overcome such limitations, photoinitiated polymerization was chosen to synthesize nanocomposite materials. By this technology, called UV radiation curing, a solvent-free resin is transformed within seconds into a solid polymer upon exposure to UV-radiation at ambient temperature. The principal objective of this study was to develop photopolymerizable systems with clay particles having a layer structure (phyllosilicates). The clay mineral was made organophilic by treatment with an alkylammonium salt to allow the acrylate resin to penetrate into the expanded galleries. A morphological characterization of the materials obtained was carried out by X-rays diffraction and electronic microscopy transmission. The polymerization of the various resins under the UV exposure was followed in situ by using the real-time infrared spectroscopy (RT-FTIR) and attenuated total reflection (ATR). The results obtained show that the presence of the organoclay does not modify much the polymerization kinetics. The nanocomposite material thus obtained is transparent, insoluble int eh organic solvents and presents improved mechanical properties, compared to the neat resin and the microcomposite, for a load factor ranging between 2 and 5% wt. The addition of nanoparticles also makes it possible to reduce efficiently the brightness of coatings UV and finally confers to this material barriers properties higher than that of the photocrosslinked polymeric

  4. Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

    International Nuclear Information System (INIS)

    Ganguly, Shreyashi; Zhou Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

    2011-01-01

    Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2−x Sb x Te 3 ) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2−x Sb x Te 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties. - Graphical abstract: PbTe nanoparticles introduced into p-type Bi 2 Te 3 by incipient wetness results in decreased lattice thermal conductivity, but also acts as an electronic dopant, resulting in an overall decrease in thermoelectric performance. Highlights: ► Composites of PbTe nanoparticles in Bi 2−x Sb x Te 3 were formed by incipient wetness. ► PbTe nanoparticles leads to decreased κ l , consistent with phonon scattering. ► PbTe nanoparticles lead to decreased S and ρ, due to increased carriers. ► Collateral doping from PbTe leads to decreased ZT with increasing concentration. ► Immiscible systems are preferred for improved ZT.

  5. Synthesis of Mg–Al2O3 nanocomposites by mechanical alloying

    International Nuclear Information System (INIS)

    Liu, Jinling; Suryanarayana, C.; Ghosh, Dipankar; Subhash, Ghatu; An, Linan

    2013-01-01

    Highlights: ► Mg nanocomposites were synthesized by high-energy ball milling. ► A uniform distribution of the nano-sized reinforcements in the matrix was successfully obtained. ► The thermal stability of the formed nanocomposite was evaluated by annealing it at a high temperature. ► A reaction occurred between the initial Mg powder and Al formed as a result of the displacement reaction, leading to the formation of Mg 17 Al 12 , Al 0.58 Mg 0.42 , and Al 3 Mg 2 phases. -- Abstract: Mg–Al 2 O 3 nanocomposite powders, with Al 2 O 3 particles of 50 nm size, were synthesized by mechanical alloying starting from a mixture of 70 vol.% pure Mg and 30 vol.% Al 2 O 3 powders. A steady-state condition was obtained on milling the powder mix for about 20 h, when the crystallite size of the Mg powder was about 10 nm. The structural evolution during milling was monitored using scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction methods. The results showed that a mixture of Mg, Al 2 O 3 , and MgO phases were obtained on mechanical alloying. On annealing the milled powders at 600 °C for 30 min, a displacement reaction occurred between the Mg and Al 2 O 3 phases, when the formation of a mixture of pure Al and MgO phases was observed. Also, a reaction occurred between the initial Mg powder and Al formed as a result of the displacement reaction, leading to the formation of Mg 17 Al 12 , Al 0.58 Mg 0.42 , and Al 3 Mg 2 phases. Thus, the powder annealed after milling the Mg + Al 2 O 3 powder mix for 25 h consisted of Al, MgO and Al 3 Mg 2 phases

  6. One-step synthesis of graphene/SnO2 nanocomposites and its application in electrochemical supercapacitors.

    Science.gov (United States)

    Li, Fenghua; Song, Jiangfeng; Yang, Huafeng; Gan, Shiyu; Zhang, Qixian; Han, Dongxue; Ivaska, Ari; Niu, Li

    2009-11-11

    A one-step method was developed to fabricate conductive graphene/SnO2 (GS) nanocomposites in acidic solution. Graphite oxides were reduced by SnCl2 to graphene sheets in the presence of HCl and urea. The reducing process was accompanied by generation of SnO2 nanoparticles. The structure and composition of GS nanocomposites were confirmed by means of transmission electron microscopy, x-ray photoelectron and Raman spectroscopy. Moreover, the ultracapacitor characteristics of GS nanocomposites were studied by cyclic voltammograms (CVs) and electrical impedance spectroscopy (EIS). The CVs of GS nanocomposites are nearly rectangular in shape and the specific capacitance degrades slightly as the voltage scan rate is increased. The EIS of GS nanocomposites presents a phase angle close to pi/2 at low frequency, indicating a good capacitive behavior. In addition, the GS nanocomposites could be promisingly applied in many fields such as nanoelectronics, ultracapacitors, sensors, nanocomposites, batteries and gas storage.

  7. Enhanced visible-light photocatalytic activities of Ag{sub 3}PO{sub 4}/MWCNT nanocomposites fabricated by facile in situ precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bo [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Li, Zhongyu, E-mail: zhongyuli@mail.tsinghua.edu.cn [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Changzhou Expansion New Stuff Technology Limited Company, Changzhou 213122 (China); Jilin Institute of Chemical Technology, Jilin 132022 (China); Xu, Song, E-mail: cyanine123@163.com [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Han, Dandan; Lu, Dayong [Jilin Institute of Chemical Technology, Jilin 132022 (China)

    2014-05-01

    Highlights: • Ag{sub 3}PO{sub 4}/MWCNT composites were facilely fabricated via in situ precipitation method. • Ag{sub 3}PO{sub 4}/MWCNT composites exhibited enhanced visible-light photocatalytic activity. • Ag{sub 3}PO{sub 4}/MWCNT composites showed good photostability compared with Ag{sub 3}PO{sub 4} particles. • Possible photocatalytic mechanism under visible-light irradiation was proposed. - Abstract: The Ag{sub 3}PO{sub 4}/MWCNT nanocomposites were facilely fabricated via in situ precipitation method by adding (NH{sub 4}){sub 2}HPO{sub 4} into the mixture of multi-walled carbon nanotube (MWCNT) and AgNO{sub 3} solution under stirring. The as-prepared Ag{sub 3}PO{sub 4}/MWCNT nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), the Brunauer–Emmett–Teller surface area (BET) and UV–vis diffuse reflectance spectroscopy. The TEM results showed that the Ag{sub 3}PO{sub 4} nanoparticles were distributed on the surface of MWCNT uniformly with an average diameter of 70 nm, indicating excellent loading result. The photocatalytic activities of Ag{sub 3}PO{sub 4}/MWCNT nanocomposites were investigated by degrading methylene blue (MB) and malachite green (MG) under visible-light irradiation. It was found that the Ag{sub 3}PO{sub 4}/MWCNT nanocomposite exhibited excellent photocatalytic performance with enhanced photocatalytic efficiency and good photostability compared with bare Ag{sub 3}PO{sub 4}. Furthermore, a possible mechanism for the photocatalytic oxidative degradation was also discussed.

  8. Synthesis of SWNT/Pt nanocomposites for their effective role in hydrogen storage applications

    Science.gov (United States)

    Sharma, Anshu; Andreas, Rossos; Nehra, S. P.

    2018-05-01

    Single Wall Carbon Nanotubes (SWNTs) decorated with platinum were synthesized for hydrogen storage applications. Platinum was deposited on the nanotubes using hexachloroplatinic acid (H2PtCl6.6H2O) as a precursor. Commercial SWNTs were also used to compare the results. The obtained SWNTs/Pt nanocomposite was characterized by various techniques such as powder X-ray diffractrometry (XRD), Raman Spectroscopy and Scanning Electron Microscopy (SEM). Furthermore, in the case of SWNTs/Pt, Pt nanoparticles are found to be uniformly dispersed and bound to the SWNTs acting like a single atom catalyst.

  9. Electrochemical Synthesis of Graphene/MnO2 Nano-Composite for Application to Supercapacitor Electrode.

    Science.gov (United States)

    Jeong, Kwang Ho; Lee, Hyeon Jeong; Simpson, Michael F; Jeong, Mun

    2016-05-01

    Graphene/MnO2 nano-composite was electrochemically synthesized for application to an electrode material for electrochemical supercapacitors. The nanosized needle-like MnO2 was obtained by use of a graphene substrate. The prepared composite exhibited an ideal supercapacitive behavior. A capacitance retention of 94% was achieved with a 4 h deposition time (an initial capacitance of 574 mF/cm2 at a scan rate of 20 mV/s) and the retention declined with further deposition time. The results demonstrate enhanced contact between the electrode and electrolyte and improved power density as an electrochemical capacitor.

  10. Synthesis and Mechanical Properties Investigation of Nano TiO2/Glass/Epoxy Hybrid Nanocomposite

    Directory of Open Access Journals (Sweden)

    Hamid Reza Salehi

    2015-10-01

    Full Text Available Mechanical properties of epoxy and glass/epoxy filled with 0.25, 0.5 and 1 vol% of TiO2 nanoparticles have been studied using tensile and three-point bending tests. For the TiO2/epoxy nanocomposites, the results showed that the strength and stiffness were improved, though the strain at ultimate strength point and breaking strain decreased. Moreover, the hybrid nanocomposites composed of 4 layers of woven E-glass fabric and TiO2/epoxy matrix were fabricated and cut onaxis and 45° off-axis by water jet. The results of tensile and three-point bending tests indicated a remarkable improvement in the strength and stiffness that could not be related to the mechanical improvement of the matrix. The samples containing 1 vol% nano TiO2 were improved relative to samples without the nanoparticles. The tensile strength of the on-axis and off-axis samples containing 1 vol% TiO2 increased by about 25.9% and 17.9%, in the order given, compared to that of the glass/epoxy specimens. In three-point bending test, the strength of the on-axis and off-axis specimens was improved 26% and 23.2%, respectively. In addition, the tensile stiffness of the onaxis and off-axis samples containing 1 vol% TiO2 increased, respectively, by about 14.4% and 17.5% compared to that of the glass/epoxy specimens. Also for the same on-axis and off-axis samples the three-point bending stiffness increased about 19.8% and 14.6%, respectively. The whole investigation on the microstructure of the hybrid nanocomposites illustrated that stronger interfaces between the fiber and TiO2/epoxy matrix were formed and improvement was noticed on mechanical properties of ternary composite compared to those of the fiber/epoxy composites. The analysis of damage zones of hybrid nanocomposites showed that the surface area of the damaged zone declined considerably due to the brittle behavior of TiO2-filled specimens but the area below the stress-strain curve, showing energy absorption during the test

  11. Synthesis and characterization of silver/diatomite nanocomposite by electron beam irradiation

    Science.gov (United States)

    Hanh, Truong Thi; Thu, Nguyen Thi; Quoc, Le Anh; Hien, Nguyen Quoc

    2017-10-01

    Silver nanoparticles (AgNPs) with diameter about 9 nm were deposited on diatomite by irradiation under electron beam of diatomite suspension containing 10 mM AgNO3 in 1% chitosan solution, at the dose of 20.2 kGy. The AgNPs/diatomite nanocomposite was characterized by UV-Vis spectroscopy, TEM image and energy dispersive X-ray spectroscopy (EDX). The antibacterial activity of the AgNPs/diatomite against E. coli and S. aureus was evaluated by reduction of bacterial colonies on spread plates and inhibition zone diameter on diffusion disks.

  12. Controlled synthesis of graphitic carbon-encapsulated α-Fe2O3 nanocomposite via low-temperature catalytic graphitization of biomass and its lithium storage property

    International Nuclear Information System (INIS)

    Wu, Feng; Huang, Rong; Mu, Daobin; Wu, Borong; Chen, Yongjian

    2016-01-01

    Highlights: • Facile synthesis of graphitic carbon/α-Fe 2 O 3 nano-sized anode composite. • In situ low temperature catalytic graphitization of biomass material. • Onion-like graphitic carbon layers conformally encapsulating around α-Fe 2 O 3 core. • High lithium storage properties, especially, outstanding cycle performance. - Abstract: A delicate structure of graphitic carbon-encapsulated α-Fe 2 O 3 nanocomposite is in situ constructed via “Absorption–Catalytic graphitization–Oxidation” strategy, taking use of biomass matter of degreasing cotton as carbon precursor and solution reservoir. With the assistance of the catalytic graphitization effect of iron core, onion-like graphitic carbon (GC) shell is made directly from the biomass at low temperature (650 °C). The nanosized α-Fe 2 O 3 particles would effectively mitigate volumetric strain and shorten Li + transport path during charge/discharge process. The graphitic carbon shells may promote charge transfer and protect active particles from directly exposing to electrolyte to maintain interfacial stability. As a result, the as-prepared α-Fe 2 O 3 @GC composite displays an outstanding cycle performance with a reversible capacity of 1070 mA h g −1 after 430 cycles at 0.2C, as well as a good rate capability of ∼ 950 mA h g −1 after 100 cycles at 1C and ∼ 850 mA h g −1 even up to 200 cycles at a 2C rate.

  13. Pulsed laser synthesis in liquid of efficient visible-light-active ZnO/rGO nanocomposites for improved photo-catalytic activity

    Science.gov (United States)

    Moqbel, Redhwan A.; Gondal, Mohammed A.; Qahtan, Talal F.; Dastageer, Mohamed A.

    2018-03-01

    In this work the synthesis of visible light active zinc oxide/reduced graphene oxide (ZnO/rGO) nanocomposite by laser induced fragmentation of particulates in liquid, its morphological/optical characterizations, and its application in the process of photo-catalytic degradation of toxic Rhodamine B (RhB) dye under visible radiation were studied. It is observed from the optical and morphological characterization that the anchoring of ZnO on the rGO sheets in ZnO/rGO nanocomposite considerably reduced the aggregation of ZnO (increased surface area), reduced the recombination of photo-induced charge carriers, promoted more adsorption of reactants on the catalytic surface and also enhanced and extended the light absorption in the visible spectral region. With all these improved characteristics of ZnO/rGO nanocomposite, it was found that this material as a photo-catalyst yielded an RhB degradation efficiency of 86%, as compared to the 40% degradation with pure ZnO NPs under the same experimental conditions. In the ZnO/rGO nanocomposite, rGO functions as an electron acceptor to promote charge separation, an aggregation inhibitor to enhance the active surface area, a co-catalyst, a good dye adsorber and also as a supporting matrix for ZnO.

  14. Synthesis and Characterization of WO3/Graphene Nanocomposites for Enhanced Photocatalytic Activities by One-Step In-Situ Hydrothermal Reaction

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Hu

    2018-01-01

    Full Text Available Tungsten trioxide (WO3 nanorods are synthesized on the surface of graphene (GR sheets by using a one-step in-situ hydrothermal method employing sodium tungstate (Na2WO4·2H2O and graphene oxide (GO as precursors. The resulting WO3/GR nanocomposites are characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The results confirm that the interface between WO3 nanorod and graphene contains chemical bonds. The enhanced optical absorption properties are measured by UV-vis diffuse reflectance spectra. The photocatalytic activity of the WO3/GR nanocomposites under visible light is evaluated by the photodegradation of methylene blue, where the degradation rate of WO3/GR nanocomposites is shown to be double that of pure WO3. This is attributed to the synergistic effect of graphene and the WO3 nanorod, which greatly enhances the photocatalytic performance of the prepared sample, reduces the recombination of the photogenerated electron-hole pairs and increases the visible light absorption efficiency. Finally, the photocatalytic mechanism of the WO3/GR nanocomposites is presented. The synthesis of the prepared sample is convenient, direct and environmentally friendly. The study reports a highly efficient composite photocatalyst for the degradation of contaminants that can be applied to cleaning up the environment.

  15. Novel microwave-assisted synthesis of porous g-C3N4/SnO2 nanocomposite for solar water-splitting

    Science.gov (United States)

    Seza, A.; Soleimani, F.; Naseri, N.; Soltaninejad, M.; Montazeri, S. M.; Sadrnezhaad, S. K.; Mohammadi, M. R.; Moghadam, H. Asgari; Forouzandeh, M.; Amin, M. H.

    2018-05-01

    Highly porous nanocomposites of graphitic-carbon nitride and tin oxide (g-C3N4/SnO2) were prepared through simple pyrolysis of urea molecules under microwave irradiation. The initial amount of tin was varied in order to investigate the effect of SnO2 content on preparation and properties of the composites. The synthesized nanocomposites were well-characterized by XRD, FE-SEM, HR-TEM, BET, FTIR, XPS, DRS, and PL. A homogeneous distribution of SnO2 nanoparticles with the size of less than 10 nm on the porous C3N4 sheets could be obtained, suggesting that in-situ synthesis of SnO2 nanoparticles was responsible for the formation of g-C3N4. The process likely occurred by the aid of the large amounts of OH groups formed on the surfaces of SnO2 nanoparticles during the polycondensation reactions of tin derivatives which could facilitate the pyrolysis of urea to carbon nitride. The porous nanocomposite prepared with initial tin amount of 0.175 g had high specific surface area of 195 m2 g-1 which showed high efficiency photoelectrochemical water-splitting ability. A maximum photocurrent density of 33 μA cm-2 was achieved at an applied potential of 0.5 V when testing this nanocomposite as photo-anode in water-splitting reactions under simulated visible light irradiation, introducing it as a promising visible light photoactive material.

  16. Synthesis of transparent ZnO/PMMA nanocomposite films through free-radical copolymerization of asymmetric zinc methacrylate acetate and in-situ thermal decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lin [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Li Fan, E-mail: lfan@ncu.edu.cn [Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Chen Yiwang, E-mail: ywchen@ncu.edu.cn [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wang Xiaofeng [Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China)

    2011-08-15

    In this paper, a new and simple approach for in-situ preparation of transparent ZnO/poly(metyl methacrylate) (ZnO/PMMA) nanocomposite films was developed. Poly(methyl methacrylate)-co-poly(zinc methacrylate acetate) (PMMA-co-PZnMAAc) copolymer was synthesized via free-radical polymerization between methyl methacrylate (MMA) and zinc methacrylate acetate (ZnMAAc), where asymmetric ZnMAAc with only one terminal double bond (C=C) was applied to act as the precursor for ZnO nanocrystals and could avoid cross-link. Subsequently, transparent ZnO/PMMA nanocomposite films were obtained by in-situ thermal decomposition. Scanning electron microscope (SEM) image revealed that ZnO nanocrystals were homogeneously dispersed in PMMA matrix. With thermal decomposition time increasing, the absorption intensity in UV region and photoluminescence intensity of ZnO/PMMA nanocomposite films enhanced. However, the optical properties diminished when the thermal decomposition temperature increased. The TGA measurement displayed ZnO/PMMA nanocomposite films prepared by the in-situ synthesis method possessed better thermal stability compared with those prepared by the physical blending method and pristine PMMA films. - Highlights: > ZnO/PMMA hybrid films were prepared via free-radical polymerization and in-situ thermal decomposition. > ZnO NCs are homogeneously dispersed in the PMMA matrix and these films have good optical properties. > Thermal stability of these films is improved compared with those of physically blending ones.

  17. Hydrothermal synthesis of MnO2/CNT nanocomposite with a CNT core/porous MnO2 sheath hierarchy architecture for supercapacitors

    Science.gov (United States)

    Xia, Hui; Wang, Yu; Lin, Jianyi; Lu, Li

    2012-01-01

    MnO2/carbon nanotube [CNT] nanocomposites with a CNT core/porous MnO2 sheath hierarchy architecture are synthesized by a simple hydrothermal treatment. X-ray diffraction and Raman spectroscopy analyses reveal that birnessite-type MnO2 is produced through the hydrothermal synthesis. Morphological characterization reveals that three-dimensional hierarchy architecture is built with a highly porous layer consisting of interconnected MnO2 nanoflakes uniformly coated on the CNT surface. The nanocomposite with a composition of 72 wt.% (K0.2MnO2·0.33 H2O)/28 wt.% CNT has a large specific surface area of 237.8 m2/g. Electrochemical properties of the CNT, the pure MnO2, and the MnO2/CNT nanocomposite electrodes are investigated by cyclic voltammetry and electrochemical impedance spectroscopy measurements. The MnO2/CNT nanocomposite electrode exhibits much larger specific capacitance compared with both the CNT electrode and the pure MnO2 electrode and significantly improves rate capability compared to the pure MnO2 electrode. The superior supercapacitive performance of the MnO2/CNT nancomposite electrode is due to its high specific surface area and unique hierarchy architecture which facilitate fast electron and ion transport.

  18. Synthesis, Characterization, and Photocatalytic Activity of Zn-Doped SnO2/Zn2SnO4 Coupled Nanocomposites

    Directory of Open Access Journals (Sweden)

    Tiekun Jia

    2014-01-01

    Full Text Available Zn-doped SnO2/Zn2SnO4 nanocomposites were prepared via a two-step hydrothermal synthesis method. The as-prepared samples were characterized by X-ray diffraction (XRD, field-emission scanning electron microscopy (FESEM, transmission electron microscopy (TEM, UV-vis diffuse reflection spectroscopy, and adsorption-desorption isotherms. The results of FESEM and TEM showed that the as-prepared Zn-doped SnO2/Zn2SnO4 nanocomposites are composed of numerous nanoparticles with the size ranging from 20 nm to 50 nm. The specific surface area of the as-prepared Zn-doped SnO2/Zn2SnO4 nanocomposites is estimated to be 71.53 m2/g by the Brunauer-Emmett-Teller (BET method. The photocatalytic activity was evaluated by the degradation of methylene blue (MB, and the resulting showed that Zn-doped SnO2/Zn2SnO4 nanocomposites exhibited excellent photocatalytic activity due to their higher specific surface area and surface charge carrier transfer.

  19. A microwave assisted one-pot route synthesis of bimetallic PtPd alloy cubic nanocomposites and their catalytic reduction for 4-nitrophenol

    Science.gov (United States)

    Zhang, Jian; Gan, Wei; Fu, Xucheng; Hao, Hequn

    2017-10-01

    We herein report a simple, rapid, and eco-friendly chemical route to the one-pot synthesis of bimetallic PtPd alloy cubic nanocomposites under microwave irradiation. During this process, water was employed as an environmentally benign solvent, while dimethylformamide served as a mild reducing agent, and polyvinylpyrrolidone was used as both a dispersant and a stabilizer. The structure, morphology, and composition of the resulting alloy nanocomposites were examined by x-ray diffraction, transmission electron microscopy, and energy dispersive x-ray spectroscopy. A detailed study was then carried out into the catalytic activity of the PtPd nanocomposites with a Pt:Pd molar ratio of 50:50 in the reduction of 4-nitrophenol (4-NP) by sodium borohydride as a model reaction. Compared with pristine Pt and Pd monometallic nanoparticles (PtNPs and PdNPs), the bimetallic PtPd alloy nanocomposites exhibited enhanced catalytic activities and were readily recyclable in the reduction of 4-NP due to synergistic effects.

  20. Chemical synthesis, characterization and electro-oxidation of hydrazine via a carbon paste electrode modified with poly (P-phenylendiamine/Al2O3) nanocomposite

    International Nuclear Information System (INIS)

    Emamgholizadeh, Abbas; Omrani, Abdollah; Rostami, Abbas Ali

    2012-01-01

    Highlights: ► A novel nanocomposite based on poly (P-phenylendiamine)/alumina was synthesized. ► It was observed that the nanocomposite increased the surface catalytic activity of CPE toward oxidation of hydrazine. ► The EIS measurements showed that the values of R ct decreases by the nanoalumina presence. - Abstract: In this article, the chemical synthesis and characterization of Al 2 O 3 nanoparticles dispersed into poly (P-phenylendiamine) (PpDP) was reported. The morphology, conductivity and structure of the nanocomposite was characterized by scanning electron microscopy (SEM), four probe testing and XRD experiment, respectively. Catalytic activity and stability for the oxidation of hydrazine were studied by using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The results show that the nanocomposite significantly enhances the effective surface area and the catalytic activity of the CPE (carbon paste electrode) for oxidation of hydrazine. The results obtained confirmed that the dispersion of the Al 2 O 3 particles is connected with catalytic response to a higher activity. The nanotubular morphology of poly (P-phenylendiamine) helps in the effective dispersion of Al 2 O 3 particles facilitating the easier access of hydrazine to the catalytic sites. The poly (P-phenylendiamine) nanotubes modified with Al 2 O 3 nanoparticles cause a great increase in electroactivity and the electro-catalytic properties of CPE for hydrazine oxidation.

  1. Synthesis of transparent ZnO/PMMA nanocomposite films through free-radical copolymerization of asymmetric zinc methacrylate acetate and in-situ thermal decomposition

    International Nuclear Information System (INIS)

    Zhang Lin; Li Fan; Chen Yiwang; Wang Xiaofeng

    2011-01-01

    In this paper, a new and simple approach for in-situ preparation of transparent ZnO/poly(metyl methacrylate) (ZnO/PMMA) nanocomposite films was developed. Poly(methyl methacrylate)-co-poly(zinc methacrylate acetate) (PMMA-co-PZnMAAc) copolymer was synthesized via free-radical polymerization between methyl methacrylate (MMA) and zinc methacrylate acetate (ZnMAAc), where asymmetric ZnMAAc with only one terminal double bond (C=C) was applied to act as the precursor for ZnO nanocrystals and could avoid cross-link. Subsequently, transparent ZnO/PMMA nanocomposite films were obtained by in-situ thermal decomposition. Scanning electron microscope (SEM) image revealed that ZnO nanocrystals were homogeneously dispersed in PMMA matrix. With thermal decomposition time increasing, the absorption intensity in UV region and photoluminescence intensity of ZnO/PMMA nanocomposite films enhanced. However, the optical properties diminished when the thermal decomposition temperature increased. The TGA measurement displayed ZnO/PMMA nanocomposite films prepared by the in-situ synthesis method possessed better thermal stability compared with those prepared by the physical blending method and pristine PMMA films. - Highlights: → ZnO/PMMA hybrid films were prepared via free-radical polymerization and in-situ thermal decomposition. → ZnO NCs are homogeneously dispersed in the PMMA matrix and these films have good optical properties. → Thermal stability of these films is improved compared with those of physically blending ones.

  2. Synthesis of Nm-PHB (nanomelanin-polyhydroxy butyrate) nanocomposite film and its protective effect against biofilm-forming multi drug resistant Staphylococcus aureus.

    Science.gov (United States)

    Kiran, George Seghal; Jackson, Stephen A; Priyadharsini, Sethu; Dobson, Alan D W; Selvin, Joseph

    2017-08-22

    Melanin is a dark brown ubiquitous photosynthetic pigment which have many varied and ever expanding applications in fabrication of radio-protective materials, food packaging, cosmetics and in medicine. In this study, melanin production in a Pseudomonas sp. which was isolated from the marine sponge Tetyrina citirna was optimized employing one-factor at a time experiments and characterized for chemical nature and stability. Following sonication nucleated nanomelanin (Nm) particles were formed and evaluated for antibacterial and antioxidant properties. Nanocomposite film was fabricated using combinations (% w/v) of polyhydroxy butyrate-nanomelanin (PHB:Nm) blended with 1% glycerol. The Nm was found to be spherical in shape with a diameter of 100-140 nm and showed strong antimicrobial activity against both Gram positive and Gram negative bacteria. The Nm-PHB nanocomposite film was homogeneous, smooth, without any cracks, and flexible. XRD and DSC data indicated that the film was crystalline in nature, and was thermostable up to 281.87 °C. This study represents the first report on the synthesis of Nm and fabrication of Nm-PHB nanocomposite film which show strong protective effect against multidrug resistant Staphyloccoccus aureus. Thus this Nm-PHB nanocomposite film may find utility as packaging material for food products by protecting the food products from oxidation and bacterial contamination.

  3. Synthesis, characterization and optical properties of hybridized CdS-PVA nanocomposites

    International Nuclear Information System (INIS)

    Wang Hongmei; Chen Zhe; Fang Pengfei; Wang Shaojie

    2007-01-01

    Hybrid nanocomposites of CdS nanoparticles embedded in poly(vinyl alcohol)(PVA) matrixes had been prepared and characterized. The -OH groups acted as the coordination sites for cadmium ion aggregations and nanosized CdS particles were successfully grown in situ at these sites with the release of S 2- ions from thioacetamide. The density and size of the nanoparticles were found to be a function of molar quantity of cadmium ion used. X-ray diffraction results showed that the obtained CdS nanoparticles were hexagonal phase. Ionic clustering within the PVA matrix occurred and had provided a confined medium for particles growth in uniform size. The optical properties of the prepared CdS-PVA hybrid nanocomposites were characterized by absorption and emission spectroscopies. The absorption spectra showed a blue shift as compared to bulk CdS band-gap. The photoluminescence studies indicated the emission peak observed in samples could be assigned to the optical transition of the first excitonic state of the CdS nanoparticles

  4. Synthesis of Ag/polyaniline nanocomposite via an in situ photo-redox mechanism

    International Nuclear Information System (INIS)

    Khanna, P.K.; Singh, Narendra; Charan, Shobhit; Viswanath, A. Kasi

    2005-01-01

    Silver/polyaniline nanocomposites are prepared via in situ reduction of silver salt in aniline by mild photolysis performed with 8 W long wavelength (365 nm) and short wavelength (254 nm) radiation from UV lamp. Reduction of the silver salt in aqueous aniline leads to the formation of silver nanoparticles which in turn catalyze oxidation of aniline to polyaniline. Systematic observation of the progress of the reaction by means of absorption spectroscopy revealed that the reaction completes faster under the UV light of 254 nm wavelength than the visible source of 365 nm. The absorption bands of the reaction solution revealed that the bands at about 400-420 nm due to benzonoid ring of the polyaniline are overlapped and red-shifted due to the presence of nano-silver in powdered state. A slightly broadened X-ray diffraction (XRD) pattern indicating, small particle size (∼30 nm), is consistent with cubic silver. Scanning electron microscopy (SEM) of the nanocomposite showed a uniform size distribution with spherical and granular morphology. Thermogravimetric analysis (TGA) showed that the composites have a higher degradation temperature than polyaniline alone

  5. Simple hydrothermal synthesis of metal oxides coupled nanocomposites: Structural, optical, magnetic and photocatalytic studies

    Science.gov (United States)

    Ganeshraja, Ayyakannu Sundaram; Clara, Antoni Samy; Rajkumar, Kanniah; Wang, Yanjie; Wang, Yu; Wang, Junhu; Anbalagan, Krishnamoorthy

    2015-10-01

    The present article is focused on recent developments toward the preparation of room temperature ferromagnetic nanocomposites using better photocatalytic performance. These nanocomposites were successfully prepared by a simple hydrothermal method and their molecular formulas were confirmed as Ti0.90Sn0.10O2 (S1), 0.2CuO-Ti0.73Sn0.06Cu0.21O2-δ (S2), and Ti0.82Sn0.09Fe0.09O2-δ (S3). The ICP, XRD, DRS, FTIR, Raman, XAFS, XPS, EPR, SEM-EDX, HRSEM, HRTEM, photoluminescence and vibrating sample magnetometric measurements were employed to characterize the phase structures, morphologies, optical and magnetic properties of the photocatalysts. The local structures of Sn4+ and Fe3+ were confirmed by 119Sn and 57Fe Mössbauer analysis. The photocatalytic activities of the samples were evaluated by the degradation of methyl orange in water under visible light irradiation. Among the samples, tin doped TiO2 (S1) showed the best photocatalytic performance and stability.

  6. Solvothermal synthesis and enhanced CO2 adsorption ability of mesoporous graphene oxide-ZnO nanocomposite

    International Nuclear Information System (INIS)

    Li, Weidong; Jiang, Xia; Yang, Huayun; Liu, Qi

    2015-01-01

    Highlights: • GO–ZnO nanocomposite was prepared by solvothermal method. • Several technologies have been used to ensure and analyze the composite. • GO–ZnO has CO 2 adsorption capacity of up to 44.8 cm 3 /g at 298 K and 1 bar. • The composite has excellent adsorption/desorption recycling ability. - Abstract: Mesoporous graphene oxide–ZnO (GO–ZnO) nanocomposite has been synthesized by GO and ZnO which was prepared by solvothermal method. Power X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been used to characterize the structure and morphology of the porous GO–ZnO hybrid. With visible porosity of ZnO and GO–ZnO, N 2 adsorption–desorption measurements and pore size analysis have been investigated and compared. Comparing to ZnO, GO–ZnO showed larger Brunauer–Emmett–Teller (BET) surface area and enhanced ability on capturing CO 2 at different temperatures. Several cycles of adsorption–desorption experiments on CO 2 have been tested and it proved GO–ZnO to be potential adsorbent material with excellent cycling stability.

  7. Chitosan/CNTs green nanocomposite membrane: Synthesis, swelling and polyaromatic hydrocarbons removal

    International Nuclear Information System (INIS)

    Bibi, Saira; Yasin, Tariq; Hassan, Safia; Riaz, Muhammad; Nawaz, Mohsan

    2015-01-01

    Carbon nanotubes (CNTs) were irradiated in air at 100 kGy under gamma radiations. The Raman spectroscopy of γ-treated CNTs showed distinctive changes in the absorption bands. The CNTs were mixed with blend of chitosan (Cs)/poly (vinyl alcohol) (PVA) and crosslinked with silane. The chemical reactions between the components affected the position and intensities of the infrared bands. Scanning electron micrograph of Cs/CNTs nanocomposite membrane showed the homogeneous dispersion of CNTs in the polymer matrix. The addition of CNTs lowered its swelling in water. Naphthalene (NAPH) was selected as a model compound and its removal was studied using HPLC technique. This membrane showed fast uptake of NAPH and 87% was removed from water within 30 min. The NAPH loaded membrane showed strong chemical interactions and cannot be desorbed. The fast uptake of PAHs and the green nature of this membrane made them suitable candidates for clean-up purposes. - Highlights: • Radiation modified CNTs and chitosan gave nanocomposite membranes. • This membrane showed hydrogel properties. • This membrane was used for the removal of naphthalene. • The green nature made them suitable candidates for clean-up purposes of PAH

  8. Synthesis of nanoparticles and its effect on properties of elastomeric nanocomposites

    International Nuclear Information System (INIS)

    Shimpi, N. G.; Mishra, S.

    2010-01-01

    Calcium carbonate (CaCO 3 ) nanoparticles (9, 15, and 21 nm) were synthesized by solution spray of CaCl 2 and NH 4 HCO 3 with sodium lauryl sulfate (SLS) as a stabilizing agent, and their effect was studied on polybutadiene rubber (PBR) with variations in wt% loading (4, 8, and 12%). The results of PBR nanocomposites were compared with commercial CaCO 3 (40 μm) and fly ash (75 μm) filled PBR microcomposites. Properties such as tensile strength, young modulus, elongation at break, glass transition temperature, decomposition temperature, and abrasion resistances were determined. Profound effect in properties was observed, because nanometric size of CaCO 3 particles synthesized using solution spray technique. Maximum improvement in mechanical and flame retarding properties was observed at 8 wt% of filler loading. This increment in properties was more pronounced in 9-nm size CaCO 3 . The results were not appreciable above 8 wt% of nanofillers because of agglomeration of nanoparticles. In addition, an attempt was made to consider modeling Young's modulus of PBR-nano CaCO 3 which was predicted by modified Halpin-Tsai equation. It was observed that the predication by the Guth equation and modified Halpin-Tsai equation agreed very well with experimental, whereas the Halpin-Tsai equation can only applied to predict the modulus of rubber nanocomposites in the range of low addition of nanofiller, which agrees the Nielsen equation.

  9. Synthesis and Characterization of ZNO/MN Nanocomposite by using Sol-Gel Method

    Science.gov (United States)

    Ningsih, S. K. W.; Bahrizal, B.; Nasra, E.; Nizar, U. K.; Farisya, R.

    2018-04-01

    Zink oxide doped Mn nanocomposites were synthesized by simple sol-gel method at low temperature by using combination of aquadest with methanol as the solvent and ethylene glycol as the additive. Zink acetate dehydrate and manganese chloride tetrahydrate were used as the precursors. Composition dopants were 1,3,5,and 7%. The crystals were formed by drying at 110°C for 1 hour, after which they were heated at ± 500°C for 2 hours. The as-prepared ZnO/Mn nanocomposites were characterized by X-ray diffraction (XRD) and UV Diffuse Reflectance Spectrometer (UVDRS). The XRD patterns of the ZnO nanocrystals showed that they are mostly hexagonal wurtzite with specific peaks at 2θ = 31, 34, 36, 47, 56, 63, 66 dan 69. The sizes of the ZnO doped Mn particles produced with 1%, 3%, 5% and 7% were18-95; 17-87; 18-96 19-98 nm, respectively. UVDRS analysis showed that the band gap of the ZnO were 2,60; 2,90; 2,99 dan 3,01 eV for 1%, 3%, 5% and 7% Mn respectively.

  10. Synthesis of silicon nanocomposite for printable photovoltaic devices on flexible substrate

    Science.gov (United States)

    Odo, E. A.; Faremi, A. A.

    2017-06-01

    Renewed interest has been established in the preparation of silicon nanoparticles for electronic device applications. In this work, we report on the production of silicon powders using a simple ball mill and of silicon nanocomposite ink for screen-printable photovoltaic device on a flexible substrate. Bulk single crystalline silicon was milled for 25 h in the ball mill. The structural properties of the produced silicon nanoparticles were investigated using X-ray diffraction (XRD) and transmission electron microscopy. The results show that the particles remained highly crystalline, though transformed from their original single crystalline state to polycrystalline. The elemental composition using energy dispersive X-ray florescence spectroscopy (EDXRF) revealed that contamination from iron (Fe) and chromium (Cr) of the milling media and oxygen from the atmosphere were insignificant. The size distribution of the nanoparticles follows a lognormal pattern that ranges from 60 nm to about 1.2 μm and a mean particle size of about 103 nm. Electrical characterization of screen-printed PN structures of the nanocomposite formed by embedding the powder into a suitable water-soluble polymer on Kapton sheet reveals an enhanced photocurrent transport resulting from photo-induced carrier generation in the depletion region with energy greater that the Schottky barrier height at the metal-composite interface.

  11. Synthesis and characterization of KTiOPO4 nanocrystals and their PMMA nanocomposites

    International Nuclear Information System (INIS)

    Galceran, M; Pujol, M C; Carvajal, J J; Diaz, F; Aguilo, M; Tkaczyk, S; Kityk, I V

    2009-01-01

    KTiOPO 4 (KTP) nanocrystals have been synthesized by the modified Pechini method using ethylenediaminetetraacetic acid (EDTA) and ethylene glycol (EG) as chelating and sterification agents, respectively. Orthorhombic KTP has been obtained by calcination at 1073 K for several hours. Differential thermal and thermogravimetric (DTA-TG) analyses have been used to study the optimized heat treatment used on the precursor powder to obtain KTP nanocrystals. X-ray powder diffraction (XRD) studies on the thermally treated precursor powders indicated that nanocrystals began to crystallize at 923 K. Nanocrystals with a size dispersion distribution that fit to a lognormal function centered at 25 nm were observed by electronic microscopy. KTP nanocomposites were prepared by embedding nanocrystals in poly(methyl methacrylate) (PMMA). The photoinduced second-order susceptibility parameter and the piezo-optical coefficient were measured for the KTP nanocomposites. The optimal conditions for the generation of the frequency-doubled second harmonic generation were recorded at 391 K, and at a fundamental laser wavelength of 1064 nm and under additional treatment by polarized UV light, provided the maximum value obtained of 3.23 pm V -1 . The piezo-optical coefficients were recorded at room temperature under photoinduced treatment by a UV laser beam; the maximum value achieved was 0.673 x 10 -14 m 2 N -1 at a pump-probe delaying time of 160 s.

  12. In situ synthesis of graphene/cobalt nanocomposites and their magnetic properties

    International Nuclear Information System (INIS)

    Ji Zhenyuan; Shen Xiaoping; Song You; Zhu Guoxing

    2011-01-01

    Graphene, which possesses unique nanostructure and excellent properties, is considered as a low cost alternative to carbon nanotubes in nanocomposites. In this study, we present a simple in situ approach for the deposition of cobalt (Co) nanoparticles onto surfaces of graphene sheets by hydrazine hydrate reduction. The as-synthesized composites were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM) and thermogravimetry and differential scanning calorimetry. It was shown that the as-formed Co nanoparticles were densely and homogeneously deposited on the surfaces of the graphene sheets and as a result, the restacking of the as-reduced graphene sheets was effectively inhibited. Magnetic studies reveal that the graphene/Co nanocomposite displays ferromagnetic behavior with saturation magnetizations of 53.4 emu g -1 , remanent magnetization of 6.0 emu g -1 and coercivity of 226 Oe at room temperature, which make it promising for practical applications in future nanotechnology.

  13. Synthesis and properties of fluorescent hybrid nanocomposites based on copolyacrylates with dansyl semicarbazide units

    International Nuclear Information System (INIS)

    Buruiana, Emil C.; Chibac, Andreea L.; Buruiana, Tinca; Musteata, Valentina

    2011-01-01

    Our study examined a series of hybrid composites containing copolyacrylate with semicarbazide-dansyl groups prepared by conventional radical polymerization of monomers in the organic montmorillonite modified with alkyl chains of variable length or using the sol-gel technique. The structure and the chemical composition of the copolymers N-methacryloyloxyethylcarbamoyl-5- (dimethylaminonaphtalene-1-sulfonohydrazine)-co-methyl metahacrylate (DnsSA-co-MMA) and N-methacryloyloxyethylcarbamoyl -5-(dimethylaminonaphtalene-1-sulfonohydrazine)-co-dodecylacrylamide (DnsSA-co-DA) as well as their nanocomposites (HC-P1, HC-P2, HC-P3, HC-P4) were confirmed by spectral analysis ( 1 H NMR, FTIR, UV/vis), thermal methods and atomic force microscopy. To quantify the effect of the inorganic component compared to pure photopolymers we evaluated the properties of hybrid composites, including dielectric characterization. Additionally, these materials have been tested in experiments of fluorescence quenching by acids (HCl, p-toluenesulfonic acid, 1-S-camphorsulfonic acid), metallic cation (Cu 2+ ) and nitrobenzene. The results suggest that such nanocomposites could find applications as fluorescence-based chemosensors in homogeneous organic solutions or thin films. - Highlights: → Dansylated hybrid composites were prepared by polymerization of monomers in organo-MMT or by sol-gel. → Quenching effects by acids, Cu 2+ and nitrobenzene in solution/film were evidenced. → A fluorescence dequenching was observed for the composite with silsesquixane units. → A reversible process occurs in the composite film exposed to nitrobenzene vapors.

  14. SYNTHESIS AND CHARACTERIZATION OF BIOACTIVE GLASS/FORSTERITE NANOCOMPOSITES FOR BONE AND DENTAL IMPLANTS

    Directory of Open Access Journals (Sweden)

    REZA KAMALIAN

    2012-12-01

    Full Text Available In this research, bioactive glass (BG of the type CaO–P2O5–SiO2 and nanocrystalline forsterite (NF bioceramic were successfully synthesized via sol–gel processing method. Heat-treatment process was done to obtain phase-pure nanopowders. After characterization of each sample, the nanocomposite samples were prepared by cold pressing method and sintered at 1000°C. The samples were fully characterized by X-ray powder diffraction (XRD, scanning electron microscope (SEM, energy dispersive spectroscopy (EDX, Fourier transform infrared spectroscopy (FTIR analyses. The average nanocrystallite size was determined using the Debye-Scherrer’s formula 19.6 nm. The bioactivity was examined in vitro with respect to the ability of hydroxyapatite (HAp layer to form on the surfaces as a result of contact with simulated body fluid (SBF. According to the obtained results, the prepared nanocomposite enhances the fracture toughness of the BG matrix without deteriorating its intrinsic properties as bioactivity.

  15. Synthesis and optical properties of ZnO/MgO nanocomposite

    International Nuclear Information System (INIS)

    Chawla, Santa; Jayanthi, K.; Chander, Harish; Haranath, D.; Halder, S.K.; Kar, M.

    2008-01-01

    ZnO and its ternary alloy ZnMgO offer an excellent material system with potential in applications related to quantum well and photonic devices in UV and visible. ZnO and ZnO/MgO composite were prepared by solid-state mixing and sintering at high temperature in reducing atmosphere. ZnO/MgO nanocomposites up to 50% Mg content could be prepared by this method. The resultant sample was in powder form and has distribution of grain sizes. X-ray diffraction showed hexagonal ZnO structure with small signature of cubic MgO, which increased with increasing Mg content. Particle size estimated from Scherrer formula was in the range of 40 nm, which reflected the average crystallite size. Photoluminescence (PL) studies showed excitation peak around 290 nm (4.3 eV) and 350 nm (3.5 eV). Pure ZnO nanophosphor showed emission peak around 508 nm, which blue shifted with increasing Mg content. Time resolved decay of PL indicated decay time in the microsecond time scale. Optical absorption spectra showed bandgap about 5.6 eV for ZnO/MgO nanocomposite with 50% Mg content. The optical absorption measurement was done in the colloidal suspension form and it is expected that only nanoparticles of very small grain size were effectively contributing to the optical absorption process. The large bandgap could then be manifestation of quantum size effect

  16. Synthesis and characterization of Chitosan-CuO-MgO polymer nanocomposites

    Science.gov (United States)

    Praffulla, S. R.; Bubbly, S. G.

    2018-05-01

    In the present work, we have synthesized Chitosan-CuO-MgO nanocomposites by incorporating CuO and MgO nanoparticles in chitosan matrix. Copper oxide and magnesium oxide nanoparticles synthesized by precipitation method were characterized by X-ray diffraction and the diffraction patterns confirmed the monoclinic and cubic crystalline structures of CuO and MgO nanoparticles respectively. Chitosan-CuO-MgO composite films were prepared using solution- cast method with different concentrations of CuO and MgO nanoparticles (15 - 50 wt % with respect to chitosan) and characterized by XRD, FTIR and UV-Vis spectroscopy. The X-ray diffraction pattern shows that the crystallinity of the chitosan composite increases with increase in nanoparticle concentration. FTIR spectra confirm the chemical interaction between chitosan and metal oxide nanoparticles (CuO and MgO). UV absorbance of chitosan nanocomposites were up to 17% better than pure chitosan, thus confirming its UV shielding properties. The mechanical and electrical properties of the prepared composites are in progress.

  17. Synthesis of Silver-Chitosan Nanocomposites Colloidal by Glucose as Reducing Agent

    Directory of Open Access Journals (Sweden)

    Endang Susilowati

    2015-03-01

    Full Text Available Silver-chitosan nanocomposites colloidal was successfully performed by chemical reduction method at room temperature using glucose as reducing agent, sodium hydroxide (NaOH as accelerator reagent, silver nitrate (AgNO3 as metal precursor and chitosan as stabilizing agent. Compared to other synthetic methods, this work is green and simple. The effect of the amount of NaOH, molar ratio of AgNO3 to glucose and AgNO3 concentration towards Localized Surface Plasmon Resonance (LSPR absorption band of silver nanoparticles was investigated using UV-Vis spectrophotometer. The stability of the colloid was also studied for the first 16 weeks of storage at ambient temperature. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 402.4–414.5 nm. It is also shown that the absorption peak of LSPR were affected by NaOH amount, ratio molar AgNO3/glucose and concentration of AgNO3. The produced silver nanoparticles were spherical with dominant size range of 6 to 18 nm as shown by TEM images. All colloidals were stable without any aggregation for 16 weeks after preparation. The newly prepared silver-chitosan nanocomposites colloidal may have potential for antibacterial applications.

  18. Biomimetic synthesis of hydroxyapatite/bacterial cellulose nanocomposites for biomedical applications

    International Nuclear Information System (INIS)

    Wan, Y.Z.; Huang, Y.; Yuan, C.D.; Raman, S.; Zhu, Y.; Jiang, H.J.; He, F.; Gao, C.

    2007-01-01

    Hydroxyapatite (HAp) and bacterial cellulose (BC) are both excellent materials for use in biomaterial areas. The former has outstanding osteoconductivity and bioactivity and the latter is a high-strength nano-fibrous and extensively used biomaterial. In this work, the HAp/BC nanocomposites with a 3-dimensional (3-D) network were synthesized via a biological route by soaking both phosphorylated and unphosphorylated BCs in 1.5 simulated body fluid (SBF). Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were employed to characterize the HAp/BC nanocomposites. SEM observations demonstrated that HAp crystals were uniformly formed on the phosphorylated BC fibers after soaking in 1.5 SBF whereas little HAp was observed on individual unphosphorylated BC fibers. Our experimental results suggested that the unphosphorylated BC did not induce HAp growth and that phosphorylation effectively triggered HAp formation on BC. Mechanisms were proposed for the explanation of the experimental observations. XRD and FTIR results revealed that the HAp crystals formed on the phosphorylated BC fibers were carbonate-containing with nano-sized crystallites and crystallinities less than 1%. These structural features were close to those of biological apatites

  19. Lithium-doped hydroxyapatite nano-composites: Synthesis, characterization, gamma attenuation coefficient and dielectric properties

    Science.gov (United States)

    Badran, H.; Yahia, I. S.; Hamdy, Mohamed S.; Awwad, N. S.

    2017-01-01

    Lithium-hydroxyapatite (0, 1, 5, 10, 20, 30 and 40 wt% Li-HAp) nano-composites were synthesized by sol-gel technique followed by microwave-hydrothermal treatment. The composites were characterized by X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) and Raman techniques. Gamma attenuation coefficient and the dielectric properties for all composites were investigated. The crystallinity degree of Li-doped HAp was higher than that of un-doped HAp. Gamma attenuation coefficient values increased from 0.562 cm-1 for 0 wt% Li-HAp to 2.190 cm-1 for 40 wt% Li-HAp. The alternating current conductivity increased with increasing frequency. The concentration of Li affect the values of dielectric constant where Li doped HAp of low dielectric constant can have an advantage for healing in bone fractures. The calcium to phosphorus ratio decreased from 1.43 to 1.37 with the addition of lithium indicating the Ca deficiency in the studied composites. Our findings lead to the conclusion that Li-HAp is a new nano-composite useful for medical applications and could be doped with gamma shield materials.

  20. Biomimetic synthesis of hydroxyapatite/bacterial cellulose nanocomposites for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Y.Z. [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)]. E-mail: yzwantju@yahoo.com; Huang, Y. [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Yuan, C.D. [School of Chemical Engineering, Tianjin University, Tianjin 300072 (China); Raman, S. [Department of Community Health and Epidemiology, Queen' s University, Kingston, Ontario, Canada K7L 3N6 (Canada); Zhu, Y. [School of Chemical Engineering, Tianjin University, Tianjin 300072 (China); Jiang, H.J. [Wendeng Hospital of Orthopaedics, Shandong 264400 (China); He, F. [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Gao, C. [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2007-05-16

    Hydroxyapatite (HAp) and bacterial cellulose (BC) are both excellent materials for use in biomaterial areas. The former has outstanding osteoconductivity and bioactivity and the latter is a high-strength nano-fibrous and extensively used biomaterial. In this work, the HAp/BC nanocomposites with a 3-dimensional (3-D) network were synthesized via a biological route by soaking both phosphorylated and unphosphorylated BCs in 1.5 simulated body fluid (SBF). Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were employed to characterize the HAp/BC nanocomposites. SEM observations demonstrated that HAp crystals were uniformly formed on the phosphorylated BC fibers after soaking in 1.5 SBF whereas little HAp was observed on individual unphosphorylated BC fibers. Our experimental results suggested that the unphosphorylated BC did not induce HAp growth and that phosphorylation effectively triggered HAp formation on BC. Mechanisms were proposed for the explanation of the experimental observations. XRD and FTIR results revealed that the HAp crystals formed on the phosphorylated BC fibers were carbonate-containing with nano-sized crystallites and crystallinities less than 1%. These structural features were close to those of biological apatites.

  1. Synthesis and innovation of PLA/clay nanocomposite characterization againts to mechanical and thermal properties

    Science.gov (United States)

    Salim, S.; Agusnar, H.; Wirjosentono, B.; Tamrin; Marpaung, H.; Rihayat, T.; Nurhanifa; Adriana

    2018-03-01

    Plastic polymer is one of the most dominant materials of daily human activities because of its multifunctional nature, light and strong and anti-corrosion so it is easy to apply in various equipment. Plastic is generally derived from petroleum material so it is nonbiodegradable. Therefore, this study aims to create a breakthrough of natural and biodegradable biodegradable plastic materials from plant starch (pisok kepok starch) with the help of 3 types of acid (HNO3, HCl and H2SO4) called Poly Lactid Acid (PLA). PLA is enhanced by mixing with a clay material with a variation of 1, 3 and 5% composition to form a PLA / Clay Nanocomposite material which is expected to have superior properties and resemble conventional plastics in general. Several types of characterization were performed to see the quality of the resulting material including tensile strength test with UTM tool, thermal endurance test with TGA tool, morphological structure test using SEM tool and additional test to see filler clay quality through X-RD tool. Based on the characterization of tensile and thermal test, 5B nanocomposite with addition of 5% clay and HCl acid aid showed the best tensile strength of 36 Mpa and the highest stability was 446,63 oC. Based on the results of morphological analysis of the best samples (5B) showed good interface ties. Meanwhile, based on the results of filler analysis, the opening of clay layer d-spacing occurred at 0.355 nm.

  2. Microwave-Assisted Synthesis of Reduced Graphene Oxide/SnO2 Nanocomposite for Oxygen Reduction Reaction in Microbial Fuel Cells.

    Science.gov (United States)

    Garino, Nadia; Sacco, Adriano; Castellino, Micaela; Muñoz-Tabares, José Alejandro; Chiodoni, Angelica; Agostino, Valeria; Margaria, Valentina; Gerosa, Matteo; Massaglia, Giulia; Quaglio, Marzia

    2016-02-01

    We report on an easy, fast, eco-friendly, and reliable method for the synthesis of reduced graphene oxide/SnO2 nanocomposite as cathode material for application in microbial fuel cells (MFCs). The material was prepared starting from graphene oxide that has been reduced to graphene during the hydrothermal synthesis of the nanocomposite, carried out in a microwave system. Structural and morphological characterizations evidenced the formation of nanocomposite sheets, with SnO2 crystals of few nanometers integrated in the graphene matrix. Physico-chemical analysis revealed the formation of SnO2 nanoparticles, as well as the functionalization of the graphene by the presence of nitrogen atoms. Electrochemical characterizations put in evidence the ability of such composite to exploit a cocatalysis mechanism for the oxygen reduction reaction, provided by the presence of both SnO2 and nitrogen. In addition, the novel composite catalyst was successfully employed as cathode in seawater-based MFCs, giving electrical performances comparable to those of reference devices employing Pt as catalyst.

  3. A novel magnetic core-shell nanocomposite Fe3O4@chitosan@ZnO for the green synthesis of 2-benzimidazoles

    Science.gov (United States)

    Tian, Fei; Niu, Libo; Chen, Bo; Gao, Xuejia; Lan, Xingwang; Huo, Li; Bai, Guoyi

    2017-10-01

    A novel magnetic core-shell nanocomposite Fe3O4@Chitosan@ZnO was successfully prepared by in situ chemical precipitation method. It has a clear core-shell structure with magnetic Fe3O4 (about 160 nm in diameter) as core, chitosan as the inner shell, and ZnO as the outer shell, as demonstrated by the transmission electron microscopy and the related elemental mapping. Moreover, this nanocomposite has high magnetization (43.6 emu g-1) so that it can be easily separated from the reaction mixture within 4 s by an external magnetic field. The introduction of the natural chitosan shell, instead of the conventional SiO2 shell, and its combination with the active ZnO ensures this novel nanocomposite green character and good catalytic performance in the synthesis of 2-benzimidazoles with moderate to excellent isolated yields at room temperature. Notably, it can be recycled seven times without appreciable loss of its initial catalytic activity, demonstrating its good stability and making it an attractive candidate for the green synthesis of 2-benzimidazoles. [Figure not available: see fulltext.

  4. Synthesis and properties of ZnTe and Eu3+ ion co-doped glass nanocomposites

    International Nuclear Information System (INIS)

    Rahaman Molla, Atiar; Tarafder, Anal; Dey, Chirantan; Karmakar, Basudeb

    2014-01-01

    In this study, ZnTe (II-VI) semiconductor and Eu +3 -ion co-doped borosilicate glass has been prepared in the SiO 2 -K 2 O-CaO-BaO-B 2 O 3 glass system followed by controlled heat-treatment to produce glass nanocomposites. Glass transition temperature and crystallization peak temperature have been evaluated using DSC analysis. Dilatometric studies were carried out to evaluate thermal expansion co-efficient, glass transition temperature, and dilatometric softening temperature and found to be 10.7 × 10 −6 /K, 580° C and 628° C, respectively. TEM micrographs demonstrate formation of nano sized crystallites of less than 50 nm. The ZnTe crystal formation also established through selected area electron diffraction (SAED) analysis and high resolution images obtained through TEM studies. With increasing heat treatment time, optical transmission cut-off wavelength (λ cut-off ) shifted towards higher wavelength. Excitation spectra were recorded by monitoring emission at 613 nm corresponding to the 5 D 0 → 7 F 2 transition. An intense 394 nm excitation band corresponding to the 7 F 0 → 5 L 6 transition was observed. Emission spectra were then recorded by exciting the glass samples at 394 nm.