Nuclear Reactions in Micro/Nano-Scale Metal Particles

Science.gov (United States)

Kim, Y. E.

2013-03-01

Low-energy nuclear reactions in micro/nano-scale metal particles are described based on the theory of Bose-Einstein condensation nuclear fusion (BECNF). The BECNF theory is based on a single basic assumption capable of explaining the observed LENR phenomena; deuterons in metals undergo Bose-Einstein condensation. The BECNF theory is also a quantitative predictive physical theory. Experimental tests of the basic assumption and theoretical predictions are proposed. Potential application to energy generation by ignition at low temperatures is described. Generalized theory of BECNF is used to carry out theoretical analyses of recently reported experimental results for hydrogen-nickel system.

Rapid laser sintering of metal nano-particles inks.

Science.gov (United States)

Ermak, Oleg; Zenou, Michael; Toker, Gil Bernstein; Ankri, Jonathan; Shacham-Diamand, Yosi; Kotler, Zvi

2016-09-23

Fast sintering is of importance in additive metallization processes and especially on sensitive substrates. This work explores the mechanisms which set limits to the laser sintering rate of metal nano-particle inks. A comparison of sintering behavior of three different ink compositions with laser exposure times from micro-seconds to seconds reveals the dominant factor to be the organic content (OC) in the ink. With a low OC silver ink, of 2% only, sintering time falls below 100 μs with resistivity <×4 bulk silver. Still shorter exposure times result in line delamination and deformation with a similar outcome when the OC is increased.

Synthesis and characterization of nano hydroxyapatite using reverse micro emulsions as nano reactors

International Nuclear Information System (INIS)

Amin, S.; Siddique, T.

2015-01-01

In the present work reverse micro emulsion has been employed as nano reactors to synthesize nano crystalline Hydroxyapatite (HA). Two precursors; calcium and phosphate with different counter ions of each were used for the synthesis of HA at two different temperatures. To maintain the emulsified nano reactor, cyclohexane, TX-100 and 1-butanol including phosphate precursor was the continuous phase while aqueous Ca precursor solution was taken as the dispersed phase. Nano crystalline particles thus produced were evaluated on the basis of synthesis route, counter ions and temperature. It has been shown that emulsified nano reactors control the morphology, particle size and minimize phase transformation of HA. Characterizations of nano powder of HA are carried out using x-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), and scanning electron microscopy (SEM). HA crystallite size was found to be in the range of 20-25 nm whereas the morphology of nano particles changed from spheres to rods. (author)

Synthesis of metals chalcogenides nano-particles from H{sub 2}X (X=S, Se, Te) produced electrochemically; Synthese de nanoparticules de chalcogenures de metaux a partir de H{sub 2}X (X=S, Se, Te) produit electrochimiquement

Energy Technology Data Exchange (ETDEWEB)

Bastide, S.; Tena-Zaera, R.; Alleno, E.; Godart, C.; Levy-Clement, C. [Centre National de la Recherche Scientifique (CNRS), Lab. de Chimie Metallurgique des Terres Rares, 94 - Thiais (France); Hodes, G. [Weizmann Institute of Science, Rehovot (Israel)

2006-07-01

In this work, an electrochemical method to produce H{sub 2}X (X=S, Se, Te) hydrides in a controlled way (without being able to store them) and to transfer them directly in the synthesis reactor has been perfected. By this method, the use of H{sub 2}Te has been possible. The method uses the reduction of the elementary chalcogenide in acid medium. The Te being conductor, it can be directly used as electrode, on the other hand S and Se are insulators. Nevertheless, graphite-S or Se conducing composite electrodes can also be used. When the electrolyte composition (pH, salts presence) is well adjusted, the essential of the cathodic current is consumed by the chalcogenide reduction (low evolution of H{sub 2}) with faradic yields of about 100% for H{sub 2}S and H{sub 2}Se and 40% for HeTe. The use of H{sub 2}X allows the synthesis of nano-particles of metals chalcogenides directly by reaction with dissolved metallic salts in aqueous or organic medium and precipitation. Thus it has been possible to prepare all the CdX compounds under the form of nano-particles of diameter between 3 and 5 nm by bubbling of the gaseous hydrides in aqueous acetate solutions of Cd. In producing concomitantly H{sub 2}S and H{sub 2}Se, nano-particles of solid solutions CdS{sub x}Se{sub 1-x} have been synthesized too. (O.M.)

Synthesis and characterization of CaCO3 (calcite) nano particles from cockle shells (Anadara granosa Linn) by precipitation method

Science.gov (United States)

Widyastuti, Sri; Intan Ayu Kusuma, P.

2017-06-01

Calcium supplements can reduce the risk of osteoporosis, but they are not automatically absorbed in the gastrointestinal tract. Nanotechnology is presumed to have a capacity in resolving this problem. The preparation and characterization of calcium carbonate nano particle to improve the solubility was performed. Calcium carbonate nano particles were synthesized using precipitation method from cockle shells (Anadara granosa Linn). Samples of the cockle shells were dried in an oven at temperature of 50°C for 7 (seven) days and subsequently they were crushed and blended into fine powder that was sieved through 125-μm sieve. The synthesis of calcium carbonate nanocrystals was done by extracting using hydro chloride acid and various concentrations of sodium hydroxide were used to precipitate the calcium carbonate nano particles. The size of the nano particles was determined by SEM, XRD data, and Fourier transform infrared spectroscopy (FT-IR). The results of XRD indicated that the overall crystalline structure and phase purity of the typical calcite phase CaCO3 particles were approximately 300 nm in size. The method to find potential applications in industry to yield the large scale synthesis of aragonite nano particles by a low cost but abundant natural resource such as cockle shells is required.

A two-dimensional nodal model with turbulent effects for the synthesis of Si nano-particles by inductively coupled thermal plasmas

International Nuclear Information System (INIS)

Colombo, V; Ghedini, E; Gherardi, M; Sanibondi, P; Shigeta, M

2012-01-01

Nano-particle synthesis by means of inductively coupled plasma torches is a material process of large technological interest. Numerous parameters are involved in the optimization of this process; hence the development of numerical models for the prediction of thermal and magneto-fluid dynamics fields, precursor powder trajectories and thermal history, as well as nano-particle formation and growth, is necessary for the up-scaling of these devices from laboratory batch production to an industrial continuous process. In this work, a two-dimensional (2D) discrete-type model (nodal model) for the analysis of nano-powder nucleation and growth is presented, taking into account convection, diffusion and turbulent effects on particle formation. Discrete-type models feature high precision and reveal a great deal of information useful for clarifying the nano-particle formation process. Using Si as the precursor material, 2D simulations of a nano-particle synthesis RF plasma apparatus with a reaction chamber are carried out. Good agreement is found when comparing results obtained with this model with those coming from a well-established nucleation-coupled moment method. Moreover, the extended amount of obtainable information that characterizes the nodal model is underlined. (paper)

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.

Nano sized bismuth oxy chloride by metal organic chemical vapour deposition

Energy Technology Data Exchange (ETDEWEB)

Jagdale, Pravin, E-mail: pravin.jagdale@polito.it [Department of Applied Science and Technology (DISAT), Politecnico di Torino, 10129 (Italy); Castellino, Micaela [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Marrec, Françoise [Laboratory of Condensed Matter Physics, University of Picardie Jules Verne (UPJV), Amiens 80039 (France); Rodil, Sandra E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexicom (UNAM), Mexico D.F. 04510 (Mexico); Tagliaferro, Alberto [Department of Applied Science and Technology (DISAT), Politecnico di Torino, 10129 (Italy)

2014-06-01

Metal organic chemical vapour deposition (MOCVD) method was used to prepare thin films of bismuth based nano particles starting from bismuth salts. Nano sized bismuth oxy chloride (BiOCl) crystals were synthesized from solution containing bismuth chloride (BiCl{sub 3}) in acetone (CH{sub 3}-CO-CH{sub 3}). Self-assembly of nano sized BiOCl crystals were observed on the surface of silicon, fused silica, copper, carbon nanotubes and aluminium substrates. Various synthesis parameters and their significant impact onto the formation of self-assembled nano-crystalline BiOCl were investigated. BiOCl nano particles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and Micro-Raman spectroscopy. These analyses confirm that bismuth nanometer-sized crystal structures showing a single tetragonal phase were indeed bismuth oxy chloride (BiOCl) square platelets 18–250 nm thick and a few micrometres wide.

Size characterisation of noble-metal nano-crystals formed in sapphire by ion irradiation and subsequent thermal annealing

Energy Technology Data Exchange (ETDEWEB)

Mota-Santiago, Pablo-Ernesto [Instituto de Fisica, Universidad Nacional Autonoma de Mexico A.P. 20-364 01000 Mexico D.F. (Mexico); Crespo-Sosa, Alejandro, E-mail: crespo@fisica.unam.mx [Instituto de Fisica, Universidad Nacional Autonoma de Mexico A.P. 20-364 01000 Mexico D.F. (Mexico); Jimenez-Hernandez, Jose-Luis; Silva-Pereyra, Hector-Gabriel; Reyes-Esqueda, Jorge-Alejandro; Oliver, Alicia [Instituto de Fisica, Universidad Nacional Autonoma de Mexico A.P. 20-364 01000 Mexico D.F. (Mexico)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Systematic study on the formation of Ag and Au nano-particles in Al{sub 2}O{sub 3}. Black-Right-Pointing-Pointer Annealing in a reducing atmosphere, below the metal melting point is more suitable. Black-Right-Pointing-Pointer Au nano-particles grow up to 15 nm and Ag nano-particles up to 45 nm in radius. Black-Right-Pointing-Pointer Ostwald ripening is the mechanism responsible for the formation of large nanoparticles. Black-Right-Pointing-Pointer Optical properties of metallic nano-particles in Al{sub 2}O{sub 3} can be related to their size. - Abstract: Metallic nano-particles embedded in transparent dielectrics are very important for new technological applications because of their unique optical properties. These properties depend strongly on the size and shape of the nano-particles. In order to achieve the synthesis of metallic nano-particles it has been used the technique of ion implantation. This is a very common technique because it allows the control of the depth and concentration of the metallic ions inside the sample, limited mostly by straggling, without introducing other contaminant agents. The purpose of this work was to measure the size of the nano-particles grown under different conditions in Sapphire and its size evolution during the growth process. To achieve this goal, {alpha}-Al{sub 2}O{sub 3} single crystals were implanted with Ag or Au ions at room temperature with different fluences (from 2 Multiplication-Sign 10{sup 16} ions/cm{sup 2} to 8 Multiplication-Sign 10{sup 16} ions/cm{sup 2}). Afterwards, the samples were annealed at different temperatures (from 600 Degree-Sign C to 1100 Degree-Sign C) in oxidising, reducing, Ar or N{sub 2} atmospheres. We measured the ion depth profile by Rutherford Backscattering Spectroscopy (RBS) and the nano-crystals size distribution by using two methods, the surface plasmon resonance in the optical extinction spectrum and the Transmission Electron Microscopy (TEM).

Direct large-scale synthesis of perovskite barium strontium titanate nano-particles from solutions

International Nuclear Information System (INIS)

Qi Jianquan; Wang Yu; Wan Pingchen; Long Tuli; Chan, Helen Lai Wah

2005-01-01

This paper reports a wet chemical synthesis technique for large-scale fabrication of perovskite barium strontium titanate nano-particles near room temperature and under ambient pressure. The process employs titanium alkoxide and alkali earth hydroxides as starting materials and involves very simple operation steps. Particle size and crystallinity of the particles are controllable by changing the processing parameters. Observations by X-ray diffraction, scanning electron microscopy and transmission electron microscopy TEM indicate that the particles are well-crystallized, chemically stoichiometric and ∼50nm in diameter. The nanoparticles can be sintered into ceramics at 1150 deg. C and show typical ferroelectric hysteresis loops

Scalable shape- and size-controlled synthesis of metal nano-alloys

KAUST Repository

Bakr, Osman M.

2016-01-21

Embodiments of the present disclosure provide for a continuous-flow reactor, methods of making metal nano-alloys, and metal nano-alloys. An embodiment of the continuous-flow reactor includes a first tubular component having a tubular inlet and a tubular outlet, and a heated tube-in-tube gas reactor fluidly connected to the first tubular component, wherein the heated tube-in-tube gas reactor comprises an inner tube having a gas permeable surface and an outer tube. An embodiment of the method of producing metal nano-alloys, includes contacting a reducible metal precursor and a reducing fluid in a continuous-flow reactor to form a mixed solution; and flowing the mixed solution through the continuous-flow reactor for a residence time to form the metal nano-alloys. An embodiment of the composition includes a plurality of metal nano-alloys having a monodisperse size distribution and a uniform shape distribution.

Compaction simulation of nano-crystalline metals with molecular dynamics analysis

Directory of Open Access Journals (Sweden)

Khoei A.R.

2016-01-01

Full Text Available The molecular-dynamics analysis is presented for 3D compaction simulation of nano-crystalline metals under uniaxial compaction process. The nano-crystalline metals consist of nickel and aluminum nano-particles, which are mixed with specified proportions. The EAM pair-potential is employed to model the formation of nano-particles at different temperatures, number of nano-particles, and mixing ratio of Ni and Al nano-particles to form the component into the shape of a die. The die-walls are modeled using the Lennard-Jones inter-atomic potential between the atoms of nano-particles and die-walls. The forming process is model in uniaxial compression, which is simulated until the full-dense condition is attained at constant temperature. Numerical simulations are performed by presenting the densification of nano-particles at different deformations and distribution of dislocations. Finally, the evolutions of relative density with the pressure as well as the stress-strain curves are depicted during the compaction process.

Synthesis and electrochemical performance of surface-modified nano-sized core/shell tin particles for lithium ion batteries

International Nuclear Information System (INIS)

Schmuelling, Guido; Meyer, Hinrich-Wilhelm; Placke, Tobias; Winter, Martin; Oehl, Nikolas; Knipper, Martin; Kolny-Olesiak, Joanna; Plaggenborg, Thorsten; Parisi, Jürgen

2014-01-01

Tin is able to lithiate and delithiate reversibly with a high theoretical specific capacity, which makes it a promising candidate to supersede graphite as the state-of-the-art negative electrode material in lithium ion battery technology. Nevertheless, it still suffers from poor cycling stability and high irreversible capacities. In this contribution, we show the synthesis of three different nano-sized core/shell-type particles with crystalline tin cores and different amorphous surface shells consisting of SnO x and organic polymers. The spherical size and the surface shell can be tailored by adjusting the synthesis temperature and the polymer reagents in the synthesis, respectively. We determine the influence of the surface modifications with respect to the electrochemical performance and characterize the morphology, structure, and thermal properties of the nano-sized tin particles by means of high-resolution transmission electron microscopy, x-ray diffraction, and thermogravimetric analysis. The electrochemical performance is investigated by constant current charge/discharge cycling as well as cyclic voltammetry. (paper)

Porous metal oxide particles and their methods of synthesis

Science.gov (United States)

Chen, Fanglin; Liu, Qiang

2013-03-12

Methods are generally disclosed for synthesis of porous particles from a solution formed from a leaving agent, a surfactant, and a soluble metal salt in a solvent. The surfactant congregates to form a nanoparticle core such that the metal salt forms about the nanoparticle core to form a plurality of nanoparticles. The solution is heated such that the leaving agent forms gas bubbles in the solution, and the plurality of nanoparticles congregate about the gas bubbles to form a porous particle. The porous particles are also generally disclosed and can include a particle shell formed about a core to define an average diameter from about 0.5 .mu.m to about 50 .mu.m. The particle shell can be formed from a plurality of nanoparticles having an average diameter of from about 1 nm to about 50 nm and defined by a metal salt formed about a surfactant core.

Synthesis and characterization of β-phase iron silicide nano-particles by chemical reduction

International Nuclear Information System (INIS)

Sen, Sabyasachi; Gogurla, Narendar; Banerji, Pallab; Guha, Prasanta K.; Pramanik, Panchanan

2015-01-01

Graphical abstract: - Highlights: • β-FeSi 2 nano-particle was synthesized by reducing with Mg and by diluting with MgO. • XRD profile shows the iron di-silicide phase to be semiconducting β-FeSi 2 . • HRTEM and FESEM images indicate the β-FeSi 2 average particle size to be 60–70 nm. • Absorption, reflectance and PL spectroscopy show band gap to be direct 0.87 eV. • Nano-β-FeSi 2 is p-type with hole density of 4.38 × 10 18 cm −3 and mobility 8.9 cm 2 /V s. - Abstract: Nano-particles of β-FeSi 2 have been synthesized by chemical reduction of a glassy phase of [Fe 2 O 3 , 4SiO 2 ] by Mg-metal where MgO is used as diluent to prevent the agglomeration of nano crystallites into micro-particles and also act as a negative catalyst for the formation of other phases. The sample is characterized by XRD, FESEM, HRTEM, EDX, ultra-violet-visible-infrared and PL spectroscopy and electronic properties have been investigated by Hall measurement. XRD profile shows that the synthesized powder consists of purely β-FeSi 2 semiconducting phase. The average crystallite size of β-FeSi 2 is determined to be around 65.4 nm from XRD peaks as well as from FESEM also. The optical absorption and PL spectroscopy shows that synthesized β-FeSi 2 phase is a direct band gap semiconductor with a value of 0.87 eV. Hall measurements show that β-FeSi 2 nano-particles is p-type with hole concentration of 4.38 × 10 18 cm −3 and average hole mobility of 8.9 cm 2 /V s at 300 K

Ionic liquids for nano- and microstructures preparation. Part 2: Application in synthesis.

Science.gov (United States)

Łuczak, Justyna; Paszkiewicz, Marta; Krukowska, Anna; Malankowska, Anna; Zaleska-Medynska, Adriana

2016-01-01

Ionic liquids (ILs) are widely applied to prepare metal nanoparticles and 3D semiconductor microparticles. Generally, they serve as a structuring agent or reaction medium (solvent), however it was also demonstrated that ILs can play a role of a co-solvent, metal precursor, reducing as well as surface modifying agent. The crucial role and possible types of interactions between ILs and growing particles have been presented in the Part 1 of this review paper. Part 2 of the paper gives a comprehensive overview of recent experimental studies dealing with application of ionic liquids for preparation of metal and semiconductor based nano- and microparticles. A wide spectrum of preparation routes using ionic liquids is presented, including precipitation, sol-gel technique, hydrothermal method, nanocasting and ray-mediated methods (microwave, ultrasound, UV-radiation and γ-radiation). It was found that ionic liquids formed of a 1-butyl-3-methylimidazolium [BMIM] combined with tetrafluoroborate [BF4], hexafluorophosphate [PF6], and bis(trifluoromethanesulfonyl)imide [Tf2N] are the most often used ILs in the synthesis of nano- and microparticles, due to their low melting temperature, low viscosity and good transportation properties. Nevertheless, examples of other IL classes with intrinsic nanoparticles stabilizing abilities such as phosphonium and ammonium derivatives are also presented. Experimental data revealed that structure of ILs (both anion and cation type) affects the size and shape of formed metal particles, and in some cases may even determine possibility of particles formation. The nature of the metal precursor determines its affinity to polar or nonpolar domains of ionic liquid, and therefore, the size of the nanoparticles depends on the size of these regions. Ability of ionic liquids to form varied extended interactions with particle precursor as well as other compounds presented in the reaction media (water, organic solvents etc.) provides nano- and

Silver micro- and nano-particles obtained using different glycols as reducing agents and measurement of their conductivity

Directory of Open Access Journals (Sweden)

Moudir Naïma

2016-01-01

Full Text Available Synthesis of silver micro- and nano-particles for the preparation of conductive pastes for the metallization of solar cells was realized by chemical reduction in the presence and absence of poly(vinyl-pyrrolidone (PVP. Silver nitrate was used as a precursor in the presence of three polyols (ethylene glycol, di-ethylene glycol and propylene glycol tested at experimental temperatures near their boiling points. Six samples were obtained by this protocol. Three silver powders obtained without the use of PVP have a metallic luster appearance; however, the samples produced using an excess of PVP are in the form of stable colloidal dispersions of silver nano-particles. Structural characterizations of samples using a scanning electron microscope and X-ray diffractometer show a good crystallinity and spherical morphology. From DSC and TGA analyses, it was noticed that all the nano-silvers present in the colloidal suspension have the same thermal behavior.

Synthesis of a novel poly-thiolated magnetic nano-platform for heavy metal adsorption. Role of thiol and carboxyl functions

International Nuclear Information System (INIS)

Odio, Oscar F.; Lartundo-Rojas, Luis; Palacios, Elia Guadalupe; Martínez, Ricardo; Reguera, Edilso

2016-01-01

Graphical abstract: Poly-thiols capping of magnetite nanoparticles for Pb(2+) and Cd(2+) adsorption. Display Omitted - Highlights: • A novel magnetic nano-platform containing free thiol and carboxyl groups is reported. • Thiols are protected by disulfide bridges during magnetite functionalization. • Adsorption of Pb"2"+ and Cd"2"+ onto the nano-platform was studied by XPS measurements. • Metal-sulfur interactions dominate if free thiol groups are present. • Metal-carboxyl interactions dominate if thiol groups are depleted by oxidation. - Abstract: We report a novel strategy for the synthesis of magnetic nano-platforms containing free thiol groups. It first involves the synthesis of a poly(acrylic acid) copolymer containing disulfide bridges between the linear chains through di-ester linkages, followed by the anchoring of this new ligand to magnetite nanoparticles using a ligand exchange reaction. Finally, free −SH groups are obtained by treating the resulting disulfide-functionalized magnetic nano-system with tributyl phosphine as reducing agent. The characterization of the resulting 17 nm nanoparticles (Fe_3O_4@PAA-HEDred) by FTIR and TGA confirms the attachment of the copolymer through iron carboxylates. XRD, TEM and magnetic measurements indicate an increase in the inorganic core diameter and the occurrence of strong magnetic inter-particle interactions during the exchange reaction, although coercitivity and remanence drop to near zero at room temperature. Afterwards, Fe_3O_4@PAA-HEDred nanoparticles were tested as sorbent for Pb"2"+ and Cd"2"+ cations in aqueous media. XPS measurements were performed in order to unravel the role of both carboxyl and thiol functions in the adsorption process. For the sake of comparison, the same study was performed using bare Fe_3O_4 nanoparticles and a nanosystem with disulfide groups (Fe_3O_4@DMSA). The joint analysis of the Pb 4f, Cd 3d, Fe 2p and S 2p high resolution spectra for the nanostructured materials

Synthesis of a novel poly-thiolated magnetic nano-platform for heavy metal adsorption. Role of thiol and carboxyl functions

Energy Technology Data Exchange (ETDEWEB)

Odio, Oscar F. [Instituto de Ciencia y Tecnología de Materiales, Universidad de La Habana, La Habana 10400 (Cuba); Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada-Unidad Legaria, IPN, 11500 México City (Mexico); Lartundo-Rojas, Luis [Centro de Nanociencias y Micro-Nanotecnologías, IPN, 07738 México City (Mexico); Palacios, Elia Guadalupe [Instituto Politécnico Nacional, ESIQIE, UPALM Zacatenco, 07738 México City (Mexico); Martínez, Ricardo [Instituto de Ciencia y Tecnología de Materiales, Universidad de La Habana, La Habana 10400 (Cuba); Reguera, Edilso, E-mail: edilso.reguera@gmail.com [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada-Unidad Legaria, IPN, 11500 México City (Mexico)

2016-11-15

Graphical abstract: Poly-thiols capping of magnetite nanoparticles for Pb(2+) and Cd(2+) adsorption. Display Omitted - Highlights: • A novel magnetic nano-platform containing free thiol and carboxyl groups is reported. • Thiols are protected by disulfide bridges during magnetite functionalization. • Adsorption of Pb{sup 2+} and Cd{sup 2+} onto the nano-platform was studied by XPS measurements. • Metal-sulfur interactions dominate if free thiol groups are present. • Metal-carboxyl interactions dominate if thiol groups are depleted by oxidation. - Abstract: We report a novel strategy for the synthesis of magnetic nano-platforms containing free thiol groups. It first involves the synthesis of a poly(acrylic acid) copolymer containing disulfide bridges between the linear chains through di-ester linkages, followed by the anchoring of this new ligand to magnetite nanoparticles using a ligand exchange reaction. Finally, free −SH groups are obtained by treating the resulting disulfide-functionalized magnetic nano-system with tributyl phosphine as reducing agent. The characterization of the resulting 17 nm nanoparticles (Fe{sub 3}O{sub 4}@PAA-HEDred) by FTIR and TGA confirms the attachment of the copolymer through iron carboxylates. XRD, TEM and magnetic measurements indicate an increase in the inorganic core diameter and the occurrence of strong magnetic inter-particle interactions during the exchange reaction, although coercitivity and remanence drop to near zero at room temperature. Afterwards, Fe{sub 3}O{sub 4}@PAA-HEDred nanoparticles were tested as sorbent for Pb{sup 2+} and Cd{sup 2+} cations in aqueous media. XPS measurements were performed in order to unravel the role of both carboxyl and thiol functions in the adsorption process. For the sake of comparison, the same study was performed using bare Fe{sub 3}O{sub 4} nanoparticles and a nanosystem with disulfide groups (Fe{sub 3}O{sub 4}@DMSA). The joint analysis of the Pb 4f, Cd 3d, Fe 2p and S 2p high

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

International Nuclear Information System (INIS)

Mathe, Vikas L.; Varma, Vijay; Raut, Suyog; Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K.; Bhoraskar, Sudha V.; Das, Asoka K.

2016-01-01

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

Energy Technology Data Exchange (ETDEWEB)

Mathe, Vikas L., E-mail: vlmathe@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Varma, Vijay; Raut, Suyog [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K. [High Energy Materials Research Lab, Sutarwadi, Pune 411021, Maharashtra (India); Bhoraskar, Sudha V. [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Das, Asoka K. [Utkal University, VaniVihar, Bhubaneswar, Odisha 751004 (India)

2016-04-15

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Experimental and numerical study on penetration of micro/nano diamond particle into metal by underwater shock wave

Directory of Open Access Journals (Sweden)

S Tanaka

2016-09-01

Full Text Available In order to develop composite materials, new attempting was conducted. When an explosive is exploded in water, underwater shock wave is generated. Metal plate is accelerated by the underwater shock wave and collided with diamond particles at high velocity. In this paper, pure aluminum and magnesium alloy plates are used as matrix. Micro and nano sized diamond particles were used as reinforcement. Micro diamond particles were closely coated on metal surface. Some of micro diamond particles were penetrated into aluminum. Improvement of base metal property (wearing resistance was verified by wear test for recovering metal plate. In order to confirm the deformation of the aluminum plate during the collision with diamond particles, simplified numerical simulation was conducted by using LS-DYNA software. From the result of numerical simulation, large deformation of aluminum and process of particle penetration were verified.

Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

Energy Technology Data Exchange (ETDEWEB)

Wang, Jilin [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Gu, Yunle [School of Material Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Li, Zili [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Wang, Weimin, E-mail: wangwm@hotmail.com [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Fu, Zhengyi [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2013-06-01

Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH{sub 4} played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B{sub 2}O{sub 3} and KBH{sub 4} as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH{sub 4} played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed.

Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

International Nuclear Information System (INIS)

Wang, Jilin; Gu, Yunle; Li, Zili; Wang, Weimin; Fu, Zhengyi

2013-01-01

Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH 4 played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B 2 O 3 and KBH 4 as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH 4 played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed

Synthesis of Nano-Particles in Flames

DEFF Research Database (Denmark)

Johannessen, Tue

flame burner and a premixed burner with a precursor jet. The experimental setups and results are shown and discussed in detail. Alumina powder with specific surface area between 45 m2/g and 190 m2/g was obtained.Temperature and flow fields of the flame processes are analysed by numerical simulations...... energy expression.Furthermore, the model is validated by comparison with experimental data of the flame synthesis of titania by combustion of TiCl4 previously presented by Pratsinis et al. (1996).The combination of particle dynamics and CFD simulations has proved to be an efficient method......The scope of this work is to investigate the synthesis of aluminum oxide particles in flames from the combustion of an aluminum alkoxide precursor.A general introduction to particles formation in the gas phase is presented with emphasis on the mechanisms that control the particle morphology after...

Characterization and H2-O2 reactivity of noble nano-metal tailored single wall nano-carbons

International Nuclear Information System (INIS)

K Kaneko; T Itoh; E Bekyarova; H Kanoh; S Utsumi; H Tanaka; M Yudasaka; S Iijima; S Iijima

2005-01-01

Full text of publication follows: Single wall carbon nano-tube (SWNT) and single wall carbon nano-horn (SWNH) have nano-spaces in their particles and the nano-spaces become open by oxidation. In particular, SWNH forms a unique colloidal structure which has micropores and meso-pores between the SWNH particles. Although non-treated SWNH colloids have quasi-one dimensional nano-pores [1], oxidized SWNH colloids have both of interstitial and internal nano-pores [2-5]. SWNH colloids show excellent supercritical methane storage ability [6], molecular sieving effect [7], and unique hydrogen adsorption characteristic [8]. Selective adsorptivity of SWNH colloids for H 2 and D 2 due to uncertainty principle of those molecules was shown [9-10]. As SWNH has no metallic impurities, we can study the effect of tailoring of metallic nano-particles on the surface activities of SWNH [11]. We tailored Pd or Pt nano-particles on SWNH and SWNH oxidized at 823 K (ox-SWNH) using poly[(2-oxo-pyrrolidine-1-yl)ethylene]. The oxidation of SWNH donates nano-scale windows to the single wall. The tailored metal amount was determined by TG analysis. TEM showed uniform dispersion of nano-metal particles of 2-3 nm in the diameter on SWNH. The nitrogen adsorption amount of SWNH oxidized decreases by tailoring, indicating that nano-particles are attached to the nano-scale windows. The electronic states of tailored metals were characterized by X-ray photoelectron spectroscopy. The surface activities of Pd tailored SWNH and ox-SWNH were examined for the reaction of hydrogen and oxygen near room temperature. The catalytic reactivities of Pd tailored SWNH and ox-SWNH were 4 times greater than that of Pd-dispersed activated carbon. The temperature dependence of the surface activity will be discussed with the relevance to the tube porosity. References [1] T. Ohba et al, J. Phys. Chem. In press. [2] S. Utsumi et al, J. Phys. Chem. In press. [3] C.- Min Yang, et al. Adv. Mater. In press. [4]C.M. Yang, J

Enhancement of iron content in spinach plants stimulated by magnetic nano particles

Energy Technology Data Exchange (ETDEWEB)

Yulianto, Agus; Astuti, Budi; Amalia, Saptaria Rosa [Physics Department, Faculty of Mathematics and Natural Science, Universitas Negeri Semarang (Indonesia)

2016-04-19

In our previous study, the iron content in spinach plants could be detected by magnetic susceptibility values. In the present work, magnetic nano particles were found from the iron sand. The magnetic nano particles are synthesis by using co-precipitation process and sol-gel technique. The stimulation of magnetic nano particles in the plant has been done by the provision of magnetic nano particles in growing media. After certain time, plant samples was characterized using susceptibility-meter MS2B and atomic absorption spectroscopy to measure the magnetic susceptibility and the amount of iron content that absorbed of the plant, respectively. The iron content in the spinach plants was increased when the magnetic nano particles was injected in the growing media.

Synthesis of nanosized metal particles from an aerosol

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Srećko R. Stopić

2013-10-01

Full Text Available The synthesis of metallic nanoparticles from the precursor solution of salts using the ultrasonic spray pyrolysis method was considered in this work. During the control of process parameters (surface tension and density, the concentration of solution, residence time of aerosol in the reactor, presence of additives, gas flow rate, decomposition temperature of aerosol, type of precursor and working atmosphere it is possible to guide the process in order to obtain powders with such a morphology which satisfies more complex requirements for the desired properties of advanced engineering materials.  Significant advance in the improvement of powder characteristics (lower particles sizes, better spheroidity, higher surface area was obtained by the application of the ultrasonic generator for the preparation of aerosols. Ultrasonic spray pyrolysis is performed by the action of a powerful source of ultrasound on the corresponding precursor solution forming the aerosol with a constant droplet size, which depends on the characteristics of liquid and the frequency of ultrasound. The produced aerosols were transported into the hot reactor, which enables the reaction to occur in a very small volume of a particle and formation of  nanosized powder. Spherical, nanosized particles of metals (Cu, Ag, Au, Co were produced with new and improved physical and chemical characteristics at the IME, RWTH Aachen University. The high costs associated with small quantities of produced nanosized particles represent a limitation of the USP-method. Therefore, scale up of the ultrasonic spray pyrolysis was performed as a final target in the synthesis of nanosized powder.

Synthesis of nano-structured materials by laser-ablation and their application to sensors

International Nuclear Information System (INIS)

Okada, T.; Suehiro, J.

2007-01-01

We describe the synthesis of nano-structured materials of ZnO and Pd by laser ablation and their applications to sensors. The synthesis of ZnO nano-wires was performed by nano-particle assisted deposition (NPAD) where nano-crystals were grown with nano-particles generated by laser-ablating a ZnO sintered target in an Ar background gas. The synthesized ZnO nano-wires were characterized with a scanning electron microscopy and the photoluminescent characteristics were examined under an excitation with the third harmonics of a Nd:YAG laser. The nano-wires with a diameter in the range from 50 to 150 nm and a length of up to 5 μm were taken out of the substrate by laser blow-off technique and/or sonication. It was confirmed that the nano-wires showed the stimulated emission under optical pumping, indicating a high quality of the crystalinity. Pd nano-particles were generated by laser-ablating a Pd plate in pure water. The transmission electron microscope observation revealed that Pd nano-particles with a diameter in the range from 3 nm to several tens of nanometers were produced. Using these nano-structured materials, we successfully fabricated sensors by the dielectrophoresis techniques. In the case of the ultraviolet photosensor, a detection sensitivity of 10 nW/cm 2 was achieved and in the case of hydrogen sensing, the response time of less than 10 s has been demonstrated with Pd nano-particles

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)

Synthesis, characterization, and photo-physical properties of nano-crystallites of CdyZn1-yS semiconductors

International Nuclear Information System (INIS)

Cizeron, Joel

1996-01-01

This research thesis reports the study of the synthesis of particles of semiconductor with a hybrid composition (Cd y Zn 1-y S) in an inverse micellar system. This system is made of nano-scopic water droplets suspended in oil by Brownian movement. Inverse micelles of AOT/water/alkane have been successfully used in laboratory to synthesize semiconductor particles (CdS, Ag 2 S, AgI, PbS) and metallic particles (Ag, Cu, Co) with a diameter of few nanometers. The objective has been to demonstrate the feasibility of synthesises of solid solution with a composition controlled by colloidal techniques. It was then possible to identify new information on the mechanism which governs the size of semiconductor particles. Optical properties of these particles were then studied. These nano-particles exhibit a displacement of their exciton towards high energies; it is the so-called size quantum effect. This effect has been analysed for the particles and their fluorescence [fr

Chemoselective Oxidation of Bio-Glycerol with Nano-Sized Metal Catalysts

DEFF Research Database (Denmark)

Li, Hu; Kotni, Ramakrishna; Zhang, Qiuyun

2015-01-01

to selectively oxidize glycerol and yield products with good selectivity is the use of nano-sized metal particles as heterogeneous catalysts. In this short review, recent developments in chemoselective oxidation of glycerol to specific products over nano-sized metal catalysts are described. Attention is drawn...... to various reaction parameters such as the type of the support, the size of the metal particles, and the acid/base properties of the reaction medium which were illustrated to largely influence the activity of the nanocatalyst and selectivity to the target product. - See more at: http...

Analysis of a metal filling and liner formation mechanism of the blind via with nano-Ag particles for TSV (through silicon via) interconnection

International Nuclear Information System (INIS)

Ham, Y-H; Kim, D-P; Baek, K-H; Park, K-S; Do, L-M; Kwon, K-H

2012-01-01

We investigated a metal filling and liner formation mechanism with a nano-Ag particle for the blind Si via, which is used in the via first process of through silicon via (TSV) interconnection. Using the deep reactive ion etching process, we produced the blind Si via (which is called the blind via hole or via) with a nearly vertical profile. The diameter and depth of the blind Si via were about 10 and 71 µm, respectively. The blind via holes were filled with a nano-Ag particle solution to form a metal plug or a metal liner. At this time, the Ag filling properties were monitored as a function of the volatilization rate of the Ag particle solution in the evacuating chamber. In the fast volatilization of the nano-Ag particle solution, an Ag liner formed on the inner wall of via holes. Meanwhile, both an Ag liner at the sidewall and the Ag plug at the bottom were obtained by the slow volatilization process. Finally, blind via holes fully filled with nano-Ag particles were obtained using four repetitions of the slow volatilization filling process. The proposed TSV filling process can fill large-diameter via holes over 100 µm without a seed layer and chemical mechanical planarization for TSV interconnection at low temperature. This is a simple and cost-effective TSV filling process. (paper)

Synthesis and characterization of chemically ordered FePt magnetic nano-particles

Energy Technology Data Exchange (ETDEWEB)

Srinivasa Rao, K. [Centre for Materials for Electronics Technology (C-MET), IDA phase-III, Cherlapally, Hyderabad 500 051 (India); Balaji, T., E-mail: theerthambalaji@yahoo.co [Centre for Materials for Electronics Technology (C-MET), IDA phase-III, Cherlapally, Hyderabad 500 051 (India); Lingappa, Y. [Department of Chemistry, Sri Venkateswara University, Tirupati 517 502 (India); Reddy, M.R.P.; Kumar, Arbind; Prakash, T.L. [Centre for Materials for Electronics Technology (C-MET), IDA phase-III, Cherlapally, Hyderabad 500 051 (India)

2010-08-15

Monodispersed FePt alloy magnetic nano-particles are prepared by reduction of platinum acetyl acetonate and iron acetyl acetonate salts together in the presence of oleic acid and oleyl amine stabilizers by polyol process. The particle size of FePt is in the range of 2-3 nm confirmed by transmission electron microscopy (TEM). As-synthesized FePt nano-particles are chemically disordered with face centre cubic (fcc) structure where as after vacuum annealing these particles changed to face centre tetragonal (fct) ordered structure confirmed by the X-ray diffraction technique. Magnetic coercivity of 5.247 KOe was observed for fct structure.

Synthesis and characterization of metal - metal oxide nano structured electrode materials for electrolysis of water

International Nuclear Information System (INIS)

Stoevska-Gogovska, Dafinka

2012-01-01

The goal in this Ph.D. study was to prepare hypo-hyper r f-electrocatalysts (aimed for water splitting) without or with reduced precious metals load and then to characterize them, i.e. to prove whether the goal was fulfilled. The synthesized electrocatalysts contain metallic (10% wt.) and metal-oxide phase (18% wt.), applied on a carrier (72% wt). The metallic phase was mainly cobalt one, varied from 0%, 50% wt., 80% wt. and 100%, (the rest up to 100% wt. being Ru). Only in one case the metallic phase contained 3 different metals, i.e. Co, Ru and Pt in a proportion of 80% : 10% : 10%, respectively. Metal oxide phase was TiO 2 (as a crystalline anatase) deposited on a carrier of multi walled carbon nano tubes (MWCNTs). MWCNTs were pre-activated in 28% nitric acid and effect of the activation process was studied, as well. As a reference electro catalyst for hydrogen evolution reaction, corresponding catalyst with metallic phase of pure Pt was prepared. The prepared electrocatalysts were structurally characterized by means of a number of contemporary experimental techniques. So, by means of X-ray Diffraction Analysis (XRD) the crystal state of each catalyst’s phase was determined, and the size of crystal grains was estimated. So, for Pt particles it was found that the size changes from 12 nm, in a systems with Pt as the only metal phase, to 3÷4 nm in systems that contain Co (Co:Pt = 1:1 or 4:1). It was determined as well that the anatase particles size in all synthesized catalysts is cca 4 nm. By means of Photoelectron Microscopy (XPS), the bond energy of catalyst’s components was determined, and the extent of interaction was estimated. The components oxidation state was estimated according to their peak amplitude in the XPS spectrum. So, for the carbon the peaks were identified that indicate the existence of double bond (C=C), as well as C-O, C=0 (and/or C-OH), -0-0*0 and (COO) bonds. The shift of the metallic Ru bond energy was attributed to the existence of

Synthesis of Boron Nano wires, Nano tubes, and Nano sheets

International Nuclear Information System (INIS)

Patel, R.B.; Chou, T.; Iqbal, Z.

2014-01-01

The synthesis of boron nano wires, nano tubes, and nano sheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nano materials. The materials were made by using various combinations of MgB 2 , Mg(BH 4 ) 2 , MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nano wires, boron nano tubes, and boron nano sheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications.

Synthesis of Metal Nanoparticles by Bacteria

Directory of Open Access Journals (Sweden)

Fikriye Alev Akçay

2018-04-01

Full Text Available Metal particles reduced to nano size by nanotechnological methods are confronted in many different fields such as biomedical and physicochemical, pharmaceutical, electric-electronic, automotive and food industries. Nanoparticles can be produced using chemical, physical and biological methods, of which chemical processes are in common use. However, physical and chemical methods are not environmentally friendly and economical because they require the use of high temperature, high pressure and toxic chemicals. For this reason, interest in the production of metal nanoparticles by biological methods, also called green technology, an environmentally friendly and sustainable approach, has increased in recent years. With some plant extracts and intracellular and extracellular secretions of microorganisms, some reduction reactions take place and metal nanoparticles are produced. Bacteria have been actively involved in nanotechnology in recent years due to their diversity in nature, their ease of isolation, and ease of nanoparticle synthesis. In this article, production and application of metal nanoparticles by using bacterial methods have been reviewed.

Nano-particles for therapeutical purposes: an innovative approach for the radiotherapy of cancer

International Nuclear Information System (INIS)

Borghi, E.; Said, P.; Pottier, A.; Levy, L.

2010-01-01

Nano-technology can be used to manage and assemble substances in unprecedented ways in the history of products for human health. Underlying this revolution are the possibilities for using new therapeutic processes and separating a drug's various functions (distribution, effects, etc.). This is not possible with classical drugs. Nano-medicine has made it possible to develop new approaches to treating cancer, by using nano-particles with physical effects at the scale of the malignant cell. Hard metallic oxide nano-particles have been designed so that they can play a therapeutic role when activated by x-rays. The x-rays irradiation will free electrons from the metallic oxide, these electrons will lose energy through collisions with water molecules and will create free radicals in the cells. These free radicals are very reactive and will damage the covalent bounds of the molecules located around the nano-particles. Clinical tests on man are expected to begin very soon. These 'x-ray-activable' nano-particles might set off a revolution in the practice of radiotherapy for destroying or controlling malignant tumors

Metallic nickel nano- and fine particles induce JB6 cell apoptosis through a caspase-8/AIF mediated cytochrome c-independent pathway

Directory of Open Access Journals (Sweden)

Castranova Vincent

2009-04-01

Full Text Available Abstract Background Carcinogenicity of nickel compounds has been well documented. However, the carcinogenic effect of metallic nickel is still unclear. The present study investigates metallic nickel nano- and fine particle-induced apoptosis and the signal pathways involved in this process in JB6 cells. The data obtained from this study will be of benefit for elucidating the pathological and carcinogenic potential of metallic nickel particles. Results Using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, we found that metallic nickel nanoparticles exhibited higher cytotoxicity than fine particles. Both metallic nickel nano- and fine particles induced JB6 cell apoptosis. Metallic nickel nanoparticles produced higher apoptotic induction than fine particles. Western-blot analysis showed an activation of proapoptotic factors including Fas (CD95, Fas-associated protein with death domain (FADD, caspase-8, death receptor 3 (DR3 and BID in apoptotic cells induced by metallic nickel particles. Immunoprecipitation (IP western blot analysis demonstrated the formation of the Fas-related death-inducing signaling complex (DISC in the apoptotic process. Furthermore, lamin A and beta-actin were cleaved. Moreover, we found that apoptosis-inducing factor (AIF was up-regulated and released from mitochondria to cytoplasm. Interestingly, although an up-regulation of cytochrome c was detected in the mitochondria of metallic nickel particle-treated cells, no cytochrome c release from mitochondria to cytoplasm was found. In addition, activation of antiapoptotic factors including phospho-Akt (protein kinase B and Bcl-2 was detected. Further studies demonstrated that metallic nickel particles caused no significant changes in the mitochondrial membrane permeability after 24 h treatment. Conclusion In this study, metallic nickel nanoparticles caused higher cytotoxicity and apoptotic induction than fine particles in JB6 cells. Apoptotic cell death

Synthesis of Metal Polymer Nano composites Using Ionizing Radiation

International Nuclear Information System (INIS)

Mostafa, R.S.S.

2012-01-01

we prepared a series of CdS/PVA and Ag/PVA nano composites via facile and novel synthetic steps. Our synthetic route is simpler; it does not need expensive oxidizing agents, surfactants, templates and complicated apparatus. 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 CdS/PVA and Ag/PVA nano composites processing and analysis. CdS and 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 due to interaction between CdS or Ag ions and PVA. These are: UV-Visible spectrophotometer, Transmission Electron microscope (TEM), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectrophotometer, and thermogravimetric analysis. Chapter 4 includes the obtained results and their discussions: Ultraviolet/Visible spectroscopy (UV/VIS) investigated that the as-prepared nano composites have improved optical properties. Such incremented optical properties were attributed to the nano scale dispersion (nm). The improvement in the optical properties is considered to be dependent on, Cd 2+ :S 2- molar ratio, Ag concentration, Pva content and irradiation dose. The calculated band gap energies for CdS/PVA nano composites are higher than that of bulk of CdS indicating the strong quantum confinement. The increases in band gap energy have been attributed to the crystalline size dependent properties. Transmission electron microscope images illustrated that the nano structured CdS/PVA films were found to be dispersed spherical nanoparticles with good structural homogeneity and polydispersity at either lower concentration of CdCl 2 and/or irradiation dose. Nano rod structure of CdS accompanied

Synthesis, Properties, and Applications of Low-Dimensional Carbon-Related Nano materials

International Nuclear Information System (INIS)

Mostofizadeh, A.; Li, Y.; Song, B.; Huang, Y.; Mostofizadeh, A.

2011-01-01

In recent years, many theoretical and experimental studies have been carried out to develop one of the most interesting aspects of the science and nano technology which is called carbon-related nano materials. The goal of this paper is to provide a review of some of the most exciting and important developments in the synthesis, properties, and applications of low-dimensional carbon nano materials. Carbon nano materials are formed in various structural features using several different processing methods. The synthesis techniques used to produce specific kinds of low-dimensional carbon nano materials such as zero-dimensional carbon nano materials (including fullerene, carbon-encapsulated metal nanoparticles, nano diamond, and onion-like carbons), one-dimensional carbon nano materials (including carbon nano fibers and carbon nano tubes), and two-dimensional carbon nano materials (including graphene and carbon nano walls) are discussed in this paper. Subsequently, the paper deals with an overview of the properties of the mainly important products as well as some important applications and the future outlooks of these advanced nano materials.

Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides.

Science.gov (United States)

Wu, Haohao; Yin, Jun-Jie; Wamer, Wayne G; Zeng, Mingyong; Lo, Y Martin

2014-03-01

Nano-iron metal and nano-iron oxides are among the most widely used engineered and naturally occurring nanostructures, and the increasing incidence of biological exposure to these nanostructures has raised concerns about their biotoxicity. Reactive oxygen species (ROS)-induced oxidative stress is one of the most accepted toxic mechanisms and, in the past decades, considerable efforts have been made to investigate the ROS-related activities of iron nanostructures. In this review, we summarize activities of nano-iron metal and nano-iron oxides in ROS-related redox processes, addressing in detail the known homogeneous and heterogeneous redox mechanisms involved in these processes, intrinsic ROS-related properties of iron nanostructures (chemical composition, particle size, and crystalline phase), and ROS-related bio-microenvironmental factors, including physiological pH and buffers, biogenic reducing agents, and other organic substances. Copyright © 2014. Published by Elsevier B.V.

Synthesis of alkaline-earth metal tungstates in melts of [NaNO3-M(NO3)2]eut-Na2WO4 (M=Ca, Sr, Ba) system

International Nuclear Information System (INIS)

Shurdumov, G.K.; Shurdumova, Z.V.; Cherkesov, Z.A.; Karmokov, A.M.

2006-01-01

Synthesis of alkaline earth metal tungstates in melts of eutectics of NaNO 3 -M(NO 3 ) 2 ] (M=Ca, Sr, Ba) is done. Synthesis is based in exchange reaction of calcium, strontium, and barium nitrates with sodium tungstate [ru

Laser direct synthesis and patterning of silver nano/microstructures on a polymer substrate.

Science.gov (United States)

Liu, Yi-Kai; Lee, Ming-Tsang

2014-08-27

This study presents a novel approach for the rapid fabrication of conductive nano/microscale metal structures on flexible polymer substrate (polyimide). Silver film is simultaneously synthesized and patterned on the polyimide substrate using an advanced continuous wave (CW) laser direct writing technology and a transparent, particle-free reactive silver ion ink. The location and shape of the resulting silver patterns are written by a laser beam from a digitally controlled micromirror array device. The silver patterns fabricated by this laser direct synthesis and patterning (LDSP) process exhibit the remarkably low electrical resistivity of 2.1 μΩ cm, which is compatible to the electrical resistivity of bulk silver. This novel LDSP process requires no vacuum chamber or photomasks, and the steps needed for preparation of the modified reactive silver ink are simple and straightforward. There is none of the complexity and instability associated with the synthesis of the nanoparticles that are encountered for the conventional laser direct writing technology which involves nanoparticle sintering process. This LDSP technology is an advanced method of nano/microscale selective metal patterning on flexible substrates that is fast and environmentally benign and shows potential as a feasible process for the roll-to-roll manufacturing of large area flexible electronic devices.

Engineering high power induction plasma unit at BARC for mass synthesis of refractory nano-ceramics

International Nuclear Information System (INIS)

Ghorui, S.; Sahasrabudhe, S.N.; Dhamale, G.; Das, A.K.

2013-01-01

Atmospheric pressure RF thermal plasma sources are gaining increasing importance for production of high purity novel nano-materials in different high-end technological applications. Inherent electrode-less features of the discharge together with the large volume and high energy density of the produced plasma ensures contamination free process environment and mass production ability. Reported herewith is the development of an indigenous induction plasma system for mass synthesis of nanopowders of refractory ceramic materials. The system has been tested for continuous synthesis of Al 2 O 3 nano-powder at a rate of more than 600 gm per hour and checked for its viability for bulk production of nano-particles of other refractory ceramics like Yttrium oxide and Neodymium Oxide. From collected evidences, the process of formation of the nano-particles is identified as the evaporation and subsequent homogeneous nucleation. Major features observed for alumina are complete conversion into highly spherical nano-sized particles, small particle sizes, very narrow size distribution, highly crystallite nature and mixed phases depending on the zone of collection. For alumina, the particles are found to exhibit a uni-modal distribution with peak near 15 nm

Ultrasound-assisted synthesis of nano-structured Zinc(II)-based metal-organic frameworks as precursors for the synthesis of ZnO nano-structures.

Science.gov (United States)

Bigdeli, Fahime; Ghasempour, Hosein; Azhdari Tehrani, Alireza; Morsali, Ali; Hosseini-Monfared, Hassan

2017-07-01

A 3D, porous Zn(II)-based metal-organic framework {[Zn 2 (oba) 2 (4-bpmn)]·(DMF) 1.5 } n (TMU-21), (4-bpmn=N,N'-Bis-pyridin-4-ylmethylene-naphtalene-1,5-diamine, H 2 oba=4,4'-oxybis(benzoic acid)) with nano-rods morphology under ultrasonic irradiation at ambient temperature and atmospheric pressure was prepared and characterized by scanning electron microscopy. Sonication time and concentration of initial reagents effects on the size and morphology of nano-structured MOFs were studied. Also {[Zn 2 (oba) 2 (4-bpmn)] (TMU-21) and {[Zn 2 (oba) 2 (4-bpmb)] (TMU-6), 4-bpmb=N,N'-(1,4-phenylene)bis(1-(pyridin-4-yl)methanimine) were easily prepared by mechanochemical synthesis. Nanostructures of Zinc(II) oxide were obtained by calcination of these compounds and their de-solvated analogue as activated MOFs, at 550°C under air atmosphere. As a result of that, different Nanostructures of Zinc(II) oxide were obtained. The ZnO nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and FT-IR spectroscopy. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis and characterization of nano silver ferrite composite

International Nuclear Information System (INIS)

Murthy, Y.L.N.; Kondala Rao, T.; Kasi viswanath, I.V.; Singh, Rajendra

2010-01-01

We report the synthesis of nano sized silver ferrite composite having the empirical formula AgFeO 2 by a co-precipitation method. The resulting powders are thin platelets, transparent and a rich ruby red in color in transmission. The X-ray diffraction (XRD) powder data consisted of only nine reflections, and the analysis showed the unit cell to be rhombohedral. The powders showed extensive XRD line broadening and the sizes of the crystals are calculated to be in the range 4-36.5 nm. The morphology of the silver ferrite composite studied using scanning electron microscope showed nano sized particles. The particle size is found to increase with increase in annealing temperature. The magnetic behavior, measured using a vibrating sample magnetometer, indicated a change from paramagnetic to ferromagnetic with increase in particle size.

Nano/micro particle beam for ceramic deposition and mechanical etching

International Nuclear Information System (INIS)

Chun, Doo-Man; Kim, Min-Saeng; Kim, Min-Hyeng; Ahn, Sung-Hoon; Yeo, Jun-Cheol; Lee, Caroline Sunyong

2010-01-01

Nano/micro particle beam (NPB) is a newly developed ceramic deposition and mechanical etching process. Additive (deposition) and subtractive (mechanical etching) processes can be realized in one manufacturing process using ceramic nano/micro particles. Nano- or micro-sized powders are sprayed through the supersonic nozzle at room temperature and low vacuum conditions. According to the process conditions, the ceramic powder can be deposited on metal substrates without thermal damage, and mechanical etching can be conducted in the same process with a simple change of process conditions and powders. In the present work, ceramic aluminum oxide (Al 2 O 3 ) thin films were deposited on metal substrates. In addition, the glass substrate was etched using a mask to make small channels. Deposited and mechanically etched surface morphology, coating thickness and channel depth were investigated. The test results showed that the NPB provides a feasible additive and subtractive process using ceramic powders.

Stable Poly(methacrylic acid Brush Decorated Silica Nano-Particles by ARGET ATRP for Bioconjugation

Directory of Open Access Journals (Sweden)

Marcello Iacono

2015-08-01

Full Text Available The synthesis of polymer brush decorated silica nano-particles is demonstrated by activator regeneration by electron transfer atom transfer radical polymerization (ARGET ATRP grafting of poly(tert-butyl methacrylate. ATRP initiator decorated silica nano-particles were obtained using a novel trimethylsiloxane derivatised ATRP initiator obtained by click chemistry. Comparison of de-grafted polymers with polymer obtained from a sacrificial initiator demonstrated good agreement up to 55% monomer conversion. Subsequent mild deprotection of the tert-butyl ester groups using phosphoric acid yielded highly colloidal and pH stable hydrophilic nano-particles comprising approximately 50% methacrylic acid groups. The successful bio-conjugation was achieved by immobilization of Horseradish Peroxidase to the polymer brush decorated nano-particles and the enzyme activity demonstrated in a conversion of o-phenylene diamine dihydrochloride assay.

Rod-Shaped Magnetite Nano/Microparticles Synthesis at Ambient Temperature

Directory of Open Access Journals (Sweden)

Balaprasad Ankamwar

2013-01-01

Full Text Available Here, we reported room temperature synthesis of Fe3O4 rod-shaped nano/microparticles by chemical reduction method from FeCl3 precursor and NaBH4 as the reducing agent in the presence of the pyrrole as a capping agent. The magnetic Fe3O4 particles were characterized by several methods, such as SEM, XRD, FTIR, and TGA. The average aspect ratio of Fe3O4 rod-shaped particles was ~2.8. These particles were redispersed in deionised water to form a colloidal solution and showed magnetic properties. This economical synthesis route is scalable, and Fe3O4 particles can be exploited for various applications such as MRI contrast enhancement, biodiseperations, Ni-Fe batteries, and as a catalyst.

Aloe vera Induced Biomimetic Assemblage of Nucleobase into Nanosized Particles

Science.gov (United States)

Chauhan, Arun; Zubair, Swaleha; Sherwani, Asif; Owais, Mohammad

2012-01-01

Aim Biomimetic nano-assembly formation offers a convenient and bio friendly approach to fabricate complex structures from simple components with sub-nanometer precision. Recently, biomimetic (employing microorganism/plants) synthesis of metal and inorganic materials nano-particles has emerged as a simple and viable strategy. In the present study, we have extended biological synthesis of nano-particles to organic molecules, namely the anticancer agent 5-fluorouracil (5-FU), using Aloe vera leaf extract. Methodology The 5-FU nano- particles synthesized by using Aloe vera leaf extract were characterized by UV, FT-IR and fluorescence spectroscopic techniques. The size and shape of the synthesized nanoparticles were determined by TEM, while crystalline nature of 5-FU particles was established by X-ray diffraction study. The cytotoxic effects of 5-FU nanoparticles were assessed against HT-29 and Caco-2 (human adenocarcinoma colorectal) cell lines. Results Transmission electron microscopy and atomic force microscopic techniques confirmed nano-size of the synthesized particles. Importantly, the nano-assembled 5-FU retained its anticancer action against various cancerous cell lines. Conclusion In the present study, we have explored the potential of biomimetic synthesis of nanoparticles employing organic molecules with the hope that such developments will be helpful to introduce novel nano-particle formulations that will not only be more effective but would also be devoid of nano-particle associated putative toxicity constraints. PMID:22403622

Nano-/micro metallic wire synthesis on Si substrate and their characterization

International Nuclear Information System (INIS)

Kaur, Jaskiran; Kaur, Harmanmeet; Singh, Surinder; Kanjilal, Dinakar; Chakarvarti, Shiv Kumar

2014-01-01

Nano-/micro wires of copper are grown on semiconducting Si substrate using the template method. It involves the irradiation of 8 um thick polymeric layer coated on Si with150 MeV Ni ion beam at a fluence of 2E8. Later, by using the simple technique of electrodeposition, copper nano-/micro wires were grown via template synthesis. Synthesized wires were morphologically characterized using SEM and electrical characterization was carried out by finding I-V plot

Electrochemical method for synthesizing metal-containing particles and other objects

Science.gov (United States)

Rondinone, Adam Justin; Ivanov, Ilia N.; Smith, Sean Campbell; Liang, Chengdu; Hensley, Dale K.; Moon, Ji-Won; Phelps, Tommy Joe

2017-05-02

The invention is directed to a method for producing metal-containing (e.g., non-oxide, oxide, or elemental) nano-objects, which may be nanoparticles or nanowires, the method comprising contacting an aqueous solution comprising a metal salt and water with an electrically powered electrode to form said metal-containing nano-objects dislodged from the electrode, wherein said electrode possesses a nanotextured surface that functions to confine the particle growth process to form said metal-containing nano-objects. The invention is also directed to the resulting metal-containing compositions as well as devices in which they are incorporated.

Continuous Polyol Synthesis of Metal and Metal Oxide Nanoparticles Using a Segmented Flow Tubular Reactor (SFTR

Directory of Open Access Journals (Sweden)

Andrea Testino

2015-06-01

Full Text Available Over the last years a new type of tubular plug flow reactor, the segmented flow tubular reactor (SFTR, has proven its versatility and robustness through the water-based synthesis of precipitates as varied as CaCO3, BaTiO3, Mn(1−xNixC2O4·2H2O, YBa oxalates, copper oxalate, ZnS, ZnO, iron oxides, and TiO2 produced with a high powder quality (phase composition, particle size, and shape and high reproducibility. The SFTR has been developed to overcome the classical problems of powder production scale-up from batch processes, which are mainly linked with mass and heat transfer. Recently, the SFTR concept has been further developed and applied for the synthesis of metals, metal oxides, and salts in form of nano- or micro-particles in organic solvents. This has been done by increasing the working temperature and modifying the particle carrying solvent. In this paper we summarize the experimental results for four materials prepared according to the polyol synthesis route combined with the SFTR. CeO2, Ni, Ag, and Ca3(PO42 nanoparticles (NPs can be obtained with a production rate of about 1–10 g per h. The production was carried out for several hours with constant product quality. These findings further corroborate the reliability and versatility of the SFTR for high throughput powder production.

Study of various synthesis techniques of nanomaterials

Science.gov (United States)

Patil, Madhuri; Sharma, Deepika; Dive, Avinash; Mahajan, Sandeep; Sharma, Ramphal

2018-05-01

Development of synthesis techniques of realizing nano-materials over a range of sizes, shapes, and chemical compositions is an important aspect of nanotechnology. The remarkable size dependent physical & chemical properties of particles have fascinated and inspired research activity in this direction. This paper describes some aspects on synthesis and characterization of particles of metals, metal alloys, and oxides, either in the form of thin films or bulk shapes. A brief discussion on processing of thin-films is also described.

Hydrophilic block copolymer-directed growth of lanthanum hydroxide nano-particles

Energy Technology Data Exchange (ETDEWEB)

Bouyer, F.; Sanson, N.; Gerardin, C. [Laboratoire de Materiaux Catalytiques et Catalyse en Chimie Organique, UMR 5618 CNRS-ENSCM-UM1, FR 1878, Institut Gerhardt, 34 - Montpellier (France); Destarac, M. [Centre de Recherches Rhodia Aubervilliers, 93 - Aubervilliers (France)

2006-03-15

Stable hairy lanthanum hydroxide nano-particles were synthesized in water by performing hydrolysis and condensation reactions of lanthanum cations in the presence of double hydrophilic poly-acrylic acid-b-polyacrylamide block copolymers (PAA-b-PAM). In the first step, the addition of asymmetric PAA-b-PAM copolymers (M{sub w,PAA} {<=} M{sub w,PAM}) to lanthanum salt solutions, both at pH = 5.5, induces the formation of monodispersed micellar aggregates, which are predominantly isotropic. The core of the hybrid aggregates is constituted of a lanthanum polyacrylate complex whose formation is due to bidentate coordination bonding between La{sup 3+} and acrylate groups, as shown by ATR-FTIR experiments and pH measurements. The size of the micellar aggregates depends on the molecular weight of the copolymer but is independent of the copolymer to metal ratio in solution. In the second step, the hydrolysis of lanthanum ions is induced by addition of a strong base such as sodium hydroxide. Either flocculated suspensions or stable anisotropic or spherical nano-particles of lanthanum hydrolysis products were obtained depending on the metal complexation ratio [acrylate]/[La]. The variation of that parameter also enables the control of the size of the core-corona nano-particles obtained by lanthanum hydroxylation. The asymmetry degree of the copolymer was shown to influence both the size and the shape of the particles. Elongated particles with a high aspect ratio, up to 10, were obtained with very asymmetric copolymers (M{sub w,PAM}/M{sub w,PAA}{>=}10) while shorter rice grain-like particles were obtained with a less asymmetric copolymer. The asymmetry degree also influences the value of the critical metal complexation degree required to obtain stable colloidal suspensions of polymer-stabilized lanthanum hydroxide. (authors)

Facile synthesis of nano cauliflower and nano broccoli like hierarchical superhydrophobic composite coating using PVDF/carbon soot particles via gelation technique.

Science.gov (United States)

Sahoo, Bichitra Nanda; Balasubramanian, Kandasubramanian

2014-12-15

We have elucidated a cost effective fabrication technique to produce superhydrophobic polyvinylidene fluoride (PVDF/DMF/candle soot particle and PVDF/DMF/camphor soot particle composite) porous materials. The water repellent dry composite was formed by the interaction of non-solvent (methanol) into PVDF/carbon soot particles suspension in N,N-dimethylformamide (DMF). It is seen that longer quenching time effectively changes the surface morphology of dry composites. The nano broccoli like hierarchical microstructure with micro or nano scaled roughen surface was obtained for PVDF/DMF/camphor soot particle, which reveals water contact angle of 172° with roll off angle of 2°. However, composite coating of PVDF/DMF/candle soot particle shows nano cauliflower like hierarchical, which illustrates water contact angle of 169° with roll off angle of 3°. To elucidate the enhancement of water repellent property of PVDF composites, we further divulge the evolution mechanism of nano cauliflower and nano broccoli structure. In order to evaluate the water contact angle of PVDF composites, surface diffusion of water inside the pores is investigated. Furthermore, the addition of small amount of carbon soot particles in composite not only provides the crystallization of PVDF, but also leads to dramatical amendment of surface morphology which increases the surface texture and roughness for superhydrophobicity. Copyright © 2014 Elsevier Inc. All rights reserved.

Solidification and Immobilization of Heavy metals in Soil using with nano-metallic Ca/CaO Dispersion Mixture

Directory of Open Access Journals (Sweden)

Mallampati S. R.

2013-04-01

Full Text Available In the present work, the use of nano-metallic calcium (Ca and calcium oxide (CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb in soil was investigated. With simple grinding, 85-90% of heavy metals immobilization could be achieved, while it could be enhanced to 98-100% by grinding with the addition of nano-metallic Ca/CaO dispersion mixture. By SEM-EDS elemental maps as well as semi-quantitative analysis observed that the amount of As, Cd, Cr and Pb measurable on soil particle surface decreases after nano-metallic Ca/CaO treatment. The leachable heavy metals concentrations were reduced, to the concentration lower than the Japan soil elution standard regulatory threshold, i. e., < 0.01 mg/l for As, Cd and Pb and 0.05mg/l for Cr. Whereas, the effect of soil moisture and pH on heavy metals immobilization was not much influenced. The results suggest that nano-metallic Ca/CaO mixture is suitable to be used for the gentle immobilization of heavy metals contaminated soil at normal moisture conditions.

Low-temperature molten salt synthesis and characterization of CoWO4 nano-particles

International Nuclear Information System (INIS)

Song Zuwei; Ma Junfeng; Sun Huyuan; Sun Yong; Fang Jingrui; Liu Zhengsen; Gao Chang; Liu Ye; Zhao Jingang

2009-01-01

CoWO 4 nano-particles were successfully synthesized at a low temperature of 270 deg. C by a molten salt method, and effects of such processing parameters as holding time and salt quantity on the crystallization and development of CoWO 4 crystallites were initially studied. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and photoluminescent spectra techniques (PL), respectively. Experimental results showed that the well-crystallized CoWO 4 nano-particles with ca. 45 nm in diameter could be obtained at 270 deg. C for a holding time of 8 h with 6:1 mass ratio of the salt to CoWO 4 precursor, and XRD analysis evidenced that the as-prepared sample was a pure monoclinic phase of CoWO 4 with wolframite structure. Their PL spectra revealed that the CoWO 4 nano-particles displayed a very strong PL peak at 453 nm with the excitation wavelength of 230 nm, and PL properties of CoWO 4 crystallites relied on their crystalline state, especially on their particle size.

Zirconia nano-colloids transfer from continuous hydrothermal synthesis to inkjet printing

DEFF Research Database (Denmark)

Rosa, Massimo; Gooden, P. N.; Butterworth, S.

2017-01-01

Water dispersions of nanometric yttria stabilized zirconia (YSZ) particles synthesized by Continuous Hydrothermal Synthesis are transferred into nano-inks for thin film deposition. YSZ nanoparticles are synthesized in supercritical conditions resulting in highly dispersed crystals of 10 nm in size...

Synthesis, characteristics and antimicrobial activity of ZnO nanoparticles

Science.gov (United States)

Janaki, A. Chinnammal; Sailatha, E.; Gunasekaran, S.

2015-06-01

The utilization of various plant resources for the bio synthesis of metallic nano particles is called green technology and it does not utilize any harmful protocols. Present study focuses on the green synthesis of ZnO nano particles by Zinc Carbonate and utilizing the bio-components of powder extract of dry ginger rhizome (Zingiber officinale). The ZnO nano crystallites of average size range of 23-26 nm have been synthesized by rapid, simple and eco friendly method. Zinc oxide nano particles were characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and the presence of ZnO bonding. Antimicrobial activity of ZnO nano particles was done by well diffusion method against pathogenic organisms like Klebsiella pneumonia, Staphylococcus aureus and Candida albicans and Penicillium notatum. It is observed that the ZnO synthesized in the process has the efficient antimicrobial activity.

The anomalous physical and chemical properties of gold nano-particles

International Nuclear Information System (INIS)

Cortie, M.B.

2003-01-01

Full text: Although gold is the most inert of all metallic elements, it has been discovered during the last two decades that it has interesting properties as a nano-particle. Some of the properties of interest include its activity as a heterogeneous catalyst, particularly at low temperatures, its optical properties, and the tendency of its nano-particles to adopt non-crystallographic structures. There are a number of curious aspects to catalysis by gold that are attracting academic and industrial investigation and much is still not understood about the mechanism by which they work. For example, apparently similar preparation techniques result in activities of hugely varying magnitude. In the present talk I assess the what is known about gold nano-particles, with particular reference to their physical, electronic, crystallographic and catalytic properties. It is shown that there is much evidence in favour of the belief that it is the unique electronic structure of these particles that imbues them with catalytic activity. If this is true then tighter control of the electronic structure would allow for the design of more specific and more active catalysts

Study on preparation and properties of molybdenum alloys reinforced by nano-sized ZrO2 particles

International Nuclear Information System (INIS)

Cui, Chaopeng; Gao, Yimin; Zhou, Yucheng; Wei, Shizhong; Zhang, Guoshang; Zhu, Xiangwei; Guo, Songliang

2016-01-01

The nano-sized ZrO 2 -reinforced Mo alloy was prepared by a hydrothermal method and a subsequent powder metallurgy process. During the hydrothermal process, the nano-sized ZrO 2 particles were added into the Mo powder via the hydrothermal synthesis. The grain size of Mo powder decreases obviously with the addition of ZrO 2 particles, and the fine-grain sintered structure is obtained correspondingly due to hereditation. In addition to a few of nano-sized ZrO 2 particles in grain boundaries or sub-boundaries, most are dispersed in grains. The tensile strength and yield strength have been increased by 32.33 and 53.76 %. (orig.)

Synthesis of Carbon nano structures by plasma discharge

International Nuclear Information System (INIS)

Jimenez L, M.L.

2007-01-01

Due to the great quantity of applications of the carbon nano structures (NEC) in diverse areas like: synthesis of super-resistant materials, hydrogen storage, nano sensors generation and nano catalysts, it has seen the necessity to generate new processes of synthesis of this materials as well as to already improve those existent. The present work has as objective to optimize the NEC synthesis process by means of the electric arc method which uses alternating current to high frequencies (HF), obtaining relatively clean products; that is to say, it hardly presents amorphous material neither sludges. They stand out the obtaining of carbon nano fibers (NFC) by means of a luminescent-arch discharge, in a gas mixture of He-CH 4 with 34% at. Ni/10.32% at.Y like catalyst; at a frequency of 42 kHz and low power (300 W). This method benefits the amass of the particles in both electrodes due to the high frequencies. The time of duration of the process oscillates between 5 and 20 minutes. The obtained product was characterized by scanning electron microscopy (MEB), transmission electron microscopy (MET) to determine the NEC type obtained and by X-ray diffraction analysis and Raman spectroscopy for determining the purity of the samples. The NFC is relatively free of amorphous coal. The surface and structural analysis indicates that the fibers have a half diameter of 80 nm. It is also made, a study by optical emission spectroscopy of plasma using the Swan band for determining the temperature. (Author)

Electrical memory features of ferromagnetic CoFeAlSi nano-particles embedded in metal-oxide-semiconductor matrix

International Nuclear Information System (INIS)

Lee, Ja Bin; Kim, Ki Woong; Lee, Jun Seok; An, Gwang Guk; Hong, Jin Pyo

2011-01-01

Half-metallic Heusler material Co 2 FeAl 0.5 Si 0.5 (CFAS) nano-particles (NPs) embedded in metal-oxide-semiconductor (MOS) structures with thin HfO 2 tunneling and MgO control oxides were investigated. The CFAS NPs were prepared by rapid thermal annealing. The formation of well-controlled CFAS NPs on thin HfO 2 tunneling oxide was confirmed by atomic force microscopy (AFM). Memory characteristics of CFAS NPs in MOS devices exhibited a large memory window of 4.65 V, as well as good retention and endurance times of 10 5 cycles and 10 9 s, respectively, demonstrating the potential of CFAS NPs as promising candidates for use in charge storage.

Improved nano-particle tracking analysis

International Nuclear Information System (INIS)

Walker, John G

2012-01-01

Nano-particle tracking is a method to estimate a particle size distribution by tracking the movements of individual particles, using multiple images of particles moving under Brownian motion. A novel method to recover a particle size distribution from nano-particle tracking data is described. Unlike a simple histogram-based method, the method described is able to account for the finite number of steps in each particle track and consequently for the measurement uncertainty in the step-length data. Computer simulation and experimental results are presented to demonstrate the performance of the approach compared with the current method. (paper)

Tailoring the synthesis of supported Pd catalysts towards desired structure and size of metal particles.

Science.gov (United States)

Suresh, Gatla; Radnik, Jörg; Kalevaru, Venkata Narayana; Pohl, Marga-Martina; Schneider, Matthias; Lücke, Bernhard; Martin, Andreas; Madaan, Neetika; Brückner, Angelika

2010-05-14

In a systematic study, the influence of different preparation parameters on phase composition and size of metal crystallites and particles in Pd-Cu/TiO(2) and Pd-Sb/TiO(2) catalyst materials has been explored. Temperature and atmosphere of thermal pretreatment (pure He or 10% H(2)/He), nature of metal precursors (chlorides, nitrates or acetates) as well as of ammonium additives (ammonium sulfate, nitrate, carbonate) and urea were varied with the aim of tailoring the synthesis procedure for the preferential formation of metal particles with similar size and structure as observed recently in active catalysts after long-term equilibration under catalytic reaction conditions in acetoxylation of toluene to benzylacetate. Among the metal precursors and additives, the chloride metal precursors and (NH(4))(2)SO(4) were most suitable. Upon thermal pretreatment of Pd-Sb or Pd-Cu precursors, chloroamine complexes of Pd and Cu are formed, which decompose above 220 degrees C to metallic phases independent of the atmosphere. In He, metallic Pd particles were formed with both the co-components. In H(2)/He flow, Pd-Cu precursors were converted to core-shell particles with a Cu shell and a Pd core, while Sb(1)Pd(1) and Sb(7)Pd(20) alloy phases were formed in the presence of Sb. Metal crystallites of about 40 nm agglomerate to particles of up to 150 nm in He and to even larger size in H(2)/He.

The role of nano-particles in the field of thermal spray coating technology

Science.gov (United States)

Siegmann, Stephan; Leparoux, Marc; Rohr, Lukas

2005-06-01

Nano-particles play not only a key role in recent research fields, but also in the public discussions about health and safety in nanotechnology. Nevertheless, the worldwide activities in nano-particles research increased dramatically during the last 5 to 10 years. There are different potential routes for the future production of nano-particles at large scale. The main directions envisaged are mechanical milling, wet chemical reactions or gas phase processes. Each of the processes has its specific advantages and limitations. Mechanical milling and wet chemical reactions are typically time intensive and batch processes, whereas gas phase productions by flames or plasma can be carried out continuously. Materials of interest are mainly oxide ceramics, carbides, nitrides, and pure metals. Nano-ceramics are interesting candidates for coating technologies due to expected higher coating toughness, better thermal shock and wear resistance. Especially embedded nano-carbides and-nitrides offer homogenously distributed hard phases, which enhance coatings hardness. Thermal spraying, a nearly 100 years old and world wide established coating technology, gets new possibilities thanks to optimized, nano-sized and/or nano-structured powders. Latest coating system developments like high velocity flame spraying (HVOF), cold gas deposition or liquid suspension spraying in combination with new powder qualities may open new applications and markets. This article gives an overview on the latest activities in nano-particle research and production in special relation to thermal spray coating technology.

Influence of synthesis conditions on particle morphology of ...

Indian Academy of Sciences (India)

Wintec

diffraction (XRD), scanning electron microscopy (SEM), and dynamic light scattering (DLS). Cu/ZnO ... Considerable attention has been paid to copper metal nano- particles .... And also energy dispersive scanning (EDS) analyses of sample ...

Molecular dynamics simulations of the embedding of a nano-particle into a polymer film

International Nuclear Information System (INIS)

Ochoa, J G Diaz; Binder, K; Paul, W

2006-01-01

In this work we report on molecular dynamics simulations of the embedding process of a nano-particle into a polymeric film as a function of temperature. This process has been employed experimentally in recent years to test for a shift of the glass transition of a material due to the confined film geometry and to test for the existence of a liquid-like layer on top of a glassy polymer film. The embedding process is governed thermodynamically by the prewetting properties of the polymer on the nano-particle. We show that the dynamics of the process depends on the Brownian motion characteristics of the nano-particle in and on the polymer film. It displays large sample to sample variations, suggesting that it is an activated process. On the timescales of the simulation an embedding of the nano-particle is only observed for temperatures above the bulk glass transition temperature of the polymer, agreeing with experimental observations on noble metal clusters of comparable size

Nano Materials

International Nuclear Information System (INIS)

Jin, In Ju; Lee, Ik Mo; Kwon, Yeung Gu

2006-02-01

This book introduces background of nano science such as summary, plenty room at the bottom, access way to nano technique, nanoparticles using bottom-up method which are a marvel of nature, and modern alchemy : chemical synthesis of artificial nano structure, understanding of quantum mechanics, STM/AFM, nano metal powder, ceramic nanoparticles, nano structure film, manufacture of nanoparticles using reverse micelle method, carbon nano tube, sol-gel material, nano energy material, nano catalyst nano bio material technology and spintronics.

Synthesis and characterization of CdO nano particles by the sol-gel method

Science.gov (United States)

Vadgama, V. S.; Vyas, R. P.; Jogiya, B. V.; Joshi, M. J.

2017-05-01

Cadmium Oxide (CdO) is an inorganic compound and one of the main precursors to other cadmium compounds. It finds applications in cadmium plating, storage batteries, in transparent conducting film, etc. Here, an attempt is made to synthesize CdO nano particles by sol-gel technique. The gel was prepared using cadmium nitrate tetra hydrate (Cd(NO3)2.4H2O) and aqueous ammonium hydroxide (NH4OH) as a precursor. The synthesized powder is further characterized by techniques like Powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Thermal gravimetric analysis (TGA). Powder XRD analysis suggested the nano-crystalline nature of the sample with the cubic crystal system. Nano scaled particles of spherical morphology with the size ranging from 50-100 nm are observed from TEM images. While, FT-IR study is used to confirm the presence of different functional groups. Thermo-gravimetric analysis suggests the highly thermally stable nature of the samples. The results are discussed.

Metallic oxide nano-clusters synthesis by ion implantation in high purity Fe10Cr alloy

International Nuclear Information System (INIS)

Zheng, Ce

2015-01-01

ODS (Oxide Dispersed Strengthened) steels, which are reinforced with metal dispersions of nano-oxides (based on Y, Ti and O elements), are promising materials for future nuclear reactors. The detailed understanding of the mechanisms involved in the precipitation of these nano-oxides would improve manufacturing and mechanical properties of these ODS steels, with a strong economic impact for their industrialization. To experimentally study these mechanisms, an analytical approach by ion implantation is used, to control various parameters of synthesis of these precipitates as the temperature and concentration. This study demonstrated the feasibility of this method and concerned the behaviour of alloys models (based on aluminium oxide) under thermal annealing. High purity Fe-10Cr alloys were implanted with Al and O ions at room temperature. Transmission electron microscopy observations showed that the nano-oxides appear in the Fe-10Cr matrix upon ion implantation at room temperature without subsequent annealing. The mobility of implanted elements is caused by the defects created during ion implantation, allowing the nucleation of these nanoparticles, of a few nm in diameter. These nanoparticles are composed of aluminium and oxygen, and also chromium. The high-resolution experiments show that their crystallographic structure is that of a non-equilibrium compound of aluminium oxide (cubic γ-Al 2 O 3 type). The heat treatment performed after implantation induces the growth of the nano-sized oxides, and a phase change that tends to balance to the equilibrium structure (hexagonal α-Al 2 O 3 type). These results on model alloys are fully applicable to industrial materials: indeed ion implantation reproduces the conditions of milling and heat treatments are at equivalent temperatures to those of thermo-mechanical treatments. A mechanism involving the precipitation of nano-oxide dispersed in ODS alloys is proposed in this manuscript based on the obtained experimental results

Characterization of nano structured metallic materials

International Nuclear Information System (INIS)

Marin A, M.; Gutierrez W, C.; Cruz C, R.; Angeles C, C.

1997-01-01

Nowadays the search of new materials with specific optical properties has carried out to realize a series of experiments through the polymer synthesis [(C 3 N 3 ) 2 (NH) 3 ] n doped with gold metallic nanoparticles. The thermal stability of a polymer is due to the presence of tyazine rings contained in the structure. The samples were characterized by High Resolution Transmission Electron Microscopy, X-ray diffraction by the Powder method, Ft-infrared and its thermal properties by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA). One of the purposes of this work is to obtain nano structured materials over a polymeric matrix. (Author)

Study on preparation and properties of molybdenum alloys reinforced by nano-sized ZrO{sub 2} particles

Energy Technology Data Exchange (ETDEWEB)

Cui, Chaopeng; Gao, Yimin; Zhou, Yucheng [Xi' an Jiaotong University, State Key Laboratory for Mechanical Behavior of Materials, Xi' an, Shaanxi Province (China); Wei, Shizhong [Henan University of Science and Technology, School of Materials Science and Engineering, Luoyang (China); Henan University of Science and Technology, Engineering Research Center of Tribology and Materials Protection, Ministry of Education, Luoyang (China); Zhang, Guoshang; Zhu, Xiangwei; Guo, Songliang [Henan University of Science and Technology, School of Materials Science and Engineering, Luoyang (China)

2016-03-15

The nano-sized ZrO{sub 2}-reinforced Mo alloy was prepared by a hydrothermal method and a subsequent powder metallurgy process. During the hydrothermal process, the nano-sized ZrO{sub 2} particles were added into the Mo powder via the hydrothermal synthesis. The grain size of Mo powder decreases obviously with the addition of ZrO{sub 2} particles, and the fine-grain sintered structure is obtained correspondingly due to hereditation. In addition to a few of nano-sized ZrO{sub 2} particles in grain boundaries or sub-boundaries, most are dispersed in grains. The tensile strength and yield strength have been increased by 32.33 and 53.76 %. (orig.)

Stacked dipole line source excitation of active nano-particles

DEFF Research Database (Denmark)

Arslanagic, Samel

This work investigates electromagnetic properties of cylindrical active coated nano-particles excited by a stac- ked electric dipole line source. The nano-particles consist of a silica nano-core, layered by silver, gold, or copper nano-shell. Attention is devoted to the influence of the source...... location and dipole orientation, the gain constant, and the nano-particle material composition on the electromagnetic field distributions and radiated powers. The results are contrasted to those for the magnetic line source illumination of the nano-particles....

Preparation of iron metal nano solution by anodic dissolution with high voltage

International Nuclear Information System (INIS)

Nguyen Duc Hung; Do Thanh Tuan

2012-01-01

Iron nano metal solution is prepared from anodic dissolution process with ultra- high Dc voltage. The size and shape of iron nanoparticles determined by Tem images and particle size distribution on the device LA-950 Laser Scattering Particle Distribution Analyzer V2. The concentration of nano-iron solution was determined by the analytical methods AAS atomic absorption spectrometry and Faraday's law. The difference in concentration of both methods demonstrated outside the anodic dissolution process has created the water electrolysis to form H 2 and O 2 gases and heating the solution. (author)

Ionic liquid assisted synthesis of nano Pd-Au particles and application for the detection of epinephrine, dopamine and uric acid

Energy Technology Data Exchange (ETDEWEB)

Tsai, Tsung-Hsuan; Thiagarajan, Soundappan; Chen Shenming, E-mail: smchen78@ms15.hinet.net; Cheng Chingyi

2012-01-31

Nano Pd-Au particles have been electrochemically fabricated utilizing ionic liquid as green electrolyte (1-Butyl-3-methylimidazolium tetrafluoroborate). Nano Pd-Au particles modified glassy carbon electrode (GCE) and indium tin oxide coated glass electrodes were examined using atomic force microscopy, field emission scanning electron microscope and X-ray diffraction studies. Electrodeposited nano Pd-Au particles' average diameter was found as 33 nm. Nano Pd-Au particle modified GCE was electrochemically active and stable in various pH solutions. The proposed nano particle modified GCE reduces the over potential and shows the well defined oxidation peaks for the detection of epinephrine and simultaneous determination of dopamine and uric acid (in pH 7.0 phosphate buffer solution) using cyclic voltammetry and differential pulse voltammetry.

Synthesis of carbon nano structures by plasma discharge

International Nuclear Information System (INIS)

Jimenez L, M.L.

2007-01-01

Due to the great quantity of applications of carbon neocarcinostatin (NEC) in diverse areas like: synthesis of super-resistant materials, hydrogen storage, nano sensors generation and nano catalysts, one has seen the necessity to generate new synthesis processes of these materials as well as to already improve those existent. The present work has as objective to optimize the NEC synthesis process by means of the electric arc method which uses alternating current to high frequencies (HF), obtaining relatively clean products; that is to say, it hardly presents amorphous material neither impurities. They stand out the obtaining of carbon nano fibers (NFC) by means of a luminescent-arc discharge, in a gas mixture He-CH 4 with 34% at.Ni/10.32%at.Y like catalyst; to a frequency of 42 k Hz and low power (300 W). This method benefits the agglomeration of the particles in both electrodes due to the high frequencies. The time of duration of the process oscillates between 5 and 20 minutes. The obtained product was characterized by scanning electron microscopy (MEB), transmission electron microscopy (MET) to determine the type of obtained NEC and by X-ray diffraction analysis and Raman spectroscopy to determine the purity of the samples. The NFC are relatively free of amorphous coal. The surface and structural analysis indicates that the fibers have a half diameter of 80 nm. It is also made, a study by optical emission spectroscopy of the plasma using the Swan band to determine the temperature. (Author)

Synthesis of Black and Red Mercury Sulfide Nano-Powder by Traditional Indian Method for Biomedical Application

International Nuclear Information System (INIS)

Padhi, Payodhar; Sahoo, G.; Das, K.; Ghosh, Sudipto; Panigrahi, S. C.

2008-01-01

The use of metals and minerals in the traditional Indian system of medicine known as aired is very common and is practiced since seventh century B.C. Metals were reduced to calcined powder form for medicinal purpose. For detoxification, a further step of purification of the metals and minerals with different vegetable extracts was practiced. The people of East India were using mercury and its sulfide as medicine. Gradually this secret was leaked to Arabic physicians who used mercury in skin ointment. Subsequently Italian Physicians adopted Arabic prescriptions of mercurial ointments for skin diseases. In the olden days, metals and minerals were impregnated with decoction and juice of vegetables and animal products like milk and fat for purification. These were then reduced to fine particles by milling with a pestle and mortar. It was known by then that the fineness of the powder had a significant influence on the color, texture, and medicinal properties as is cited by Charak. Nagarjun studied in detail the processing of metals and minerals, particularly mercury and the influence of the processing parameters on the medicinal values. Mercury is unique in many aspects. Indian alchemy developed a wide variety a chemical processes for the ostensible transmutation of metals and preparation of elixir of life, in which mercury occupied a prime position .The present investigation attempts to use the traditional methods as prescribed in the ancient texts to prepare mercury sulfide in both red and black form for medicinal use. XRD, SEM and HRTEM investigations of the sulfides obtained shows that the ancient Indians were able to produce nano-sized powders. Possibly this may be taken as the earliest application of the production and use of nano powder. The study proves that even in ancient time the knowledge of nano particle synthesis was prevalent and used to enhance effectiveness of medicines. Further mercury in the free form is not acceptable in medicines. The ancient

Synthesis of Black and Red Mercury Sulfide Nano-Powder by Traditional Indian Method for Biomedical Application

Science.gov (United States)

Padhi, Payodhar; Sahoo, G.; Das, K.; Ghosh, Sudipto; Panigrahi, S. C.

2008-10-01

The use of metals and minerals in the traditional Indian system of medicine known as aired is very common and is practiced since seventh century B.C. Metals were reduced to calcined powder form for medicinal purpose. For detoxification, a further step of purification of the metals and minerals with different vegetable extracts was practiced. The people of East India were using mercury and its sulfide as medicine. Gradually this secret was leaked to Arabic physicians who used mercury in skin ointment. Subsequently Italian Physicians adopted Arabic prescriptions of mercurial ointments for skin diseases. In the olden days, metals and minerals were impregnated with decoction and juice of vegetables and animal products like milk and fat for purification. These were then reduced to fine particles by milling with a pestle and mortar. It was known by then that the fineness of the powder had a significant influence on the color, texture, and medicinal properties as is cited by Charak. Nagarjun studied in detail the processing of metals and minerals, particularly mercury and the influence of the processing parameters on the medicinal values. Mercury is unique in many aspects. Indian alchemy developed a wide variety a chemical processes for the ostensible transmutation of metals and preparation of elixir of life, in which mercury occupied a prime position .The present investigation attempts to use the traditional methods as prescribed in the ancient texts to prepare mercury sulfide in both red and black form for medicinal use. XRD, SEM and HRTEM investigations of the sulfides obtained shows that the ancient Indians were able to produce nano-sized powders. Possibly this may be taken as the earliest application of the production and use of nano powder. The study proves that even in ancient time the knowledge of nano particle synthesis was prevalent and used to enhance effectiveness of medicines. Further mercury in the free form is not acceptable in medicines. The ancient

Mass synthesis of yttrium oxide nano-powders using radio frequency (RF) plasma

International Nuclear Information System (INIS)

Ghorui, S.; Sahasrabudhe, S.N.; Chakravarthy, Y.; Nagaraj, A.; Das, A.K.; Dhamale, G.

2014-01-01

Mass synthesis of nano-phase Yttrium Oxide (Y 2 O 3 ) from commercially available coarse grain powder is reported. Nano-sized high purity Y 2 O 3 is an important and critical constituent of ceramics like YAG (Yttrium aluminum garnet: Y 3 Al 5 O 12 ) for laser applications. The system is characterized in terms of its thermal and electrical behavior. Boltzmann plot technique is used to measure axial variation of temperature of the generated plasma. The synthesized particles are characterized in terms of XRD, SEM, TEM and BET analyses for qualification of the developed system. Major features observed are efficient conversion into nanometer-sized highly spherical particles, narrow size distribution, highly crystallite nature and highly pure phases. The particle distribution (from TEM) peaks within 20-30 nm. Average particle sizes determined from different methods like XRD, TEM and BET are very close to each other and point toward particle sizes within 20 to 30 nm

Indentation analysis of nano-particle using nano-contact mechanics models during nano-manipulation based on atomic force microscopy

International Nuclear Information System (INIS)

Daeinabi, Khadijeh; Korayem, Moharam Habibnejad

2011-01-01

Atomic force microscopy is applied to measure intermolecular forces and mechanical properties of materials, nano-particle manipulation, surface scanning and imaging with atomic accuracy in the nano-world. During nano-manipulation process, contact forces cause indentation in contact area between nano-particle and tip/substrate which is considerable at nano-scale and affects the nano-manipulation process. Several nano-contact mechanics models such as Hertz, Derjaguin–Muller–Toporov (DMT), Johnson–Kendall–Roberts–Sperling (JKRS), Burnham–Colton–Pollock (BCP), Maugis–Dugdale (MD), Carpick–Ogletree–Salmeron (COS), Pietrement–Troyon (PT), and Sun et al. have been applied as the continuum mechanics approaches at nano-scale. In this article, indentation depth and contact radius between tip and substrate with nano-particle for both spherical and conical tip shape during nano-manipulation process are analyzed and compared by applying theoretical, semiempirical, and empirical nano-contact mechanics models. The effects of adhesion force, as the main contrast point in different nano-contact mechanics models, on nano-manipulation analysis is investigated for different contact radius, and the critical point is discussed for mentioned models.

Hydrothermal synthesis of NiFe2O4 nano-particles: structural ...

Indian Academy of Sciences (India)

2. Experimental. In order to synthesize NiFe2O4 nano-particles, Ni(NO3)2· ... Nickel and iron nitrates are dissolved in distilled ... are in good agreement with standard JCPDS: 86-2267. The ... in order to evaluate micro-strain (ε) and crystallite size (D) using the ..... Impedance spectroscopic studies are useful for investigating.

Semiconductor Nano wires and Nano tubes: From Fundamentals to Diverse Applications

International Nuclear Information System (INIS)

Xiong, Q.; Grimes, C.A.; Zacharias, M.; Morral, A.F.; Hiruma, K.; Shen, G.

2012-01-01

Research in the field of semiconductor nano wires (SNWs) and nano tubes has been progressing into a mature subject with several highly interdisciplinary sub areas such as nano electronics, nano photonics, nano composites, bio sensing, optoelectronics, and solar cells. SNWs represent a unique system with novel properties associated to their one-dimensional (1D) structures. The fundamental physics concerning the formation of discrete 1D subbands, coulomb blockade effects, ballistic transport, and many-body phenomena in 1D nano wires and nano tubes provide a strong platform to explore the various scientific aspects in these nano structures. A rich variety of preparation methods have already been developed for generating well-controlled 1D nano structures and from a broad range of materials. The present special issue focuses on the recent development in the mechanistic understanding of the synthesis, the studies on electrical/optical properties of nano wires and their applications in nano electronics, nano photonics, and solar-energy harvesting. In this special issue, we have several invited review articles and contributed papers that are addressing current status of the fundamental issues related to synthesis and the diverse applications of semiconducting nano wires and nano tubes. One of the papers reviews the progress of the top-down approach of developing silicon-based vertically aligned nano wires to explore novel device architectures and integration schemes for nano electronics and clean energy applications. Another paper reviews the recent developments and experimental evidences of probing the confined optical and acoustic phonon in nonpolar semiconducting (Si and Ge) nano wires using Raman spectroscopy. The paper by K. Hiruma et al. spotlights the III semiconductor nano wires and demonstrates selective-area metal organic vapor phase epitaxy grown GaAs/In(Al)GaAs and InP/InAs/InP nano wires with heterojunctions along their axial and radial directions. The paper

Eu3+ doped yttrium oxide nano-luminophores from laser synthesis

International Nuclear Information System (INIS)

Ivanov, M.G.; Kynast, U.; Leznina, M.

2016-01-01

Nano-sized Y 2 O 3 :Eu phosphors were obtained from laser synthesis at a production rate of 25 g/h, the initial product consisting of purely monoclinic material, of primary particle sizes of 20–30 nm as could be shown by powder X-ray diffraction, TEM and BET. Despite a large amount of surface adsorbed water and O–H groups, and peculiarly, nitrous oxide species, as shown by mass spectrometer coupled thermoanalysis/thermogravimetry and FTIR, the luminescence efficiency still amounted to approximately 19% relative to bulk Y 2 O 3 :Eu. On thermal conversion at 900 °C, the transformation to cubic Y 2 O 3 :Eu, now yielding particles of approximately 60 nm appeared to be complete and had an efficiency of about 68%, however, an efficiency of 93%, approaching that of bulk Y 2 O 3 :Eu, was obtained on annealing at 1200 °C. Significantly, a rapid re-formation of carbonates takes place on the calcined samples also. - Highlights: • Nano-sized Y 2 O 3 :Eu phosphors were obtained from laser synthesis. • Luminescence efficiency of monoclinic phase 20 nm nanoparticles was about 19% relative to bulk Y 2 O 3 :Eu. • Purely cubic phase 92 nm particles demonstrated efficiency of 93% of bulk Y 2 O 3 :Eu.

Synthesis and characterization of iron nano particles for the arsenic removal in water

International Nuclear Information System (INIS)

Gutierrez M, O. E.

2011-01-01

The synthesis of iron nanoparticles for the removal of metallic ions in polluted waters has been during the last years study topic for different world organizations. This work presents a synthesis method of conditioned coal with iron nanoparticles starting from the use of leaves of pineapple crown, with the purpose of using it in arsenic removal processes in aqueous phase. For the synthesis of this material, the leaves of the pineapple crown were used like supports structure of the iron nanoparticles. First, the pyrolysis appropriate temperature was determined. For the preparation of the support material, this had contact with a ferric nitrate and hexamine solution, because the preparation of the material and the coal synthesis were realized during the pyrolysis process, where the hexamine molecules and the ferric nitrate react, causing the reduction of the iron particles and their dispersion on the support material, obtaining as product a conditioned coal with iron nanoparticles. For the characterization of the materials were used techniques as: Scanning electron microscopy, Transmission electron microscopy, X-Rays Diffraction), X-Ray photoelectron spectroscopy and Moessbauer spectroscopy; moreover was determined the isoelectric point and the density of surface sites. The arsenic sorption capacity of the materials was evaluated by means of the methodology type lots where was determined the sorption kinetics and isotherms in terms of arsenic concentration and mass. (Author)

Synthesis, structural characterization and selectively catalytic properties of metal-organic frameworks with nano-sized channels: A modular design strategy

International Nuclear Information System (INIS)

Qiu Lingguang; Gu Lina; Hu Gang; Zhang Lide

2009-01-01

Modular design method for designing and synthesizing microporous metal-organic frameworks (MOFs) with selective catalytical activity was described. MOFs with both nano-sized channels and potential catalytic activities could be obtained through self-assembly of a framework unit and a catalyst unit. By selecting hexaaquo metal complexes and the ligand BTC (BTC=1,3,5-benzenetricarboxylate) as framework-building blocks and using the metal complex [M(phen) 2 (H 2 O) 2 ] 2+ (phen=1,10-phenanthroline) as a catalyst unit, a series of supramolecular MOFs 1-7 with three-dimensional nano-sized channels, i.e. [M 1 (H 2 O) 6 ].[M 2 (phen) 2 (H 2 O) 2 ] 2 .2(BTC).xH 2 O (M 1 , M 2 =Co(II), Ni(II), Cu(II), Zn(II), or Mn(II), phen=1,10-phenanthroline, BTC=1,3,5-benzenetricarboxylate, x=22-24), were synthesized through self-assembly, and their structures were characterized by IR, elemental analysis, and single-crystal X-ray diffraction. These supramolecular microporous MOFs showed significant size and shape selectivity in the catalyzed oxidation of phenols, which is due to catalytic reactions taking place in the channels of the framework. Design strategy, synthesis, and self-assembly mechanism for the construction of these porous MOFs were discussed. - Grapical abstract: A modular design strategy has been developed to synthesize microporous metal-organic frameworks with potential catalytic activity by self-assembly of the framework-building blocks and the catalyst unit

New synthesis ways of supported metallic catalysts and structure-reactivity relations in catalysis by metals; Nouvelles voies de syntheses de catalyseurs metalliques supportes et relations structure-reactivite en catalyse par les metaux

Energy Technology Data Exchange (ETDEWEB)

Uzio, D.

2006-01-15

This work deals with some research studies in the field of supported metallic catalysts. In all these works have been studied the characteristics bound to the active sites and the relations between these characteristics and the catalytic performances. The genesis of colloidal suspensions of transition metallic oxide has been used for the preparation of selective hydrogenation catalysts. At first studied in the case of palladium, this new synthesis way has been used for other metals such as Pt, Ni or Co. These studies have then been developed for preparing bimetallic catalysts (PdSn) with as supplementary aim the control of the homogeneity of the bimetallic character at the scale of nano-metric particles. These works have particularly allowed to specify the chemistry of the solutions of some metallic complexes and to rationalize the chemical processes carried out in the usual fabrication processes. Studies on size effects and the study of the reactivity of the nano and sub nano-metric particle have then been developed. Indeed, the clusters containing some atoms can see their intrinsic properties varied very strongly under the influence of several parameters as the number of atoms, the nature of the support, the reactional atmosphere. Using the knowledge acquired during the preceding works (chemistry of palladium aqueous solutions), the study of new methods of preparation of particles containing very few atoms has brought new data on the properties of hyper dispersed particles as well as on the principle of sensitivity to structure. The contribution of the support to the catalytic process for the hydrogenation of different substrates has been studied too. (O.M.)

Synthesis and applications of nano-structured iron oxides/hydroxides

African Journals Online (AJOL)

... in numerous synthesis processes. This review outlines the work being carried out on synthesis of iron oxides in nano form and their various applications. Keywords: nano iron oxides, synthesis, catalysts, magnetic properties, biomedical application. International Journal of Engineering, Science and Technology, Vol. 2, No.

Formation of DNA-network embedding ferromagnetic Cobalt nano-particles

Science.gov (United States)

Kanki, Teruo; Tanaka, Hidekazu; Shirakawa, Hideaki; Sacho, Yu; Taniguchi, Masateru; Lee, Hea-Yeon; Kawai, Tomoji; Kang, Nam-Jung; Chen, Jinwoo

2002-03-01

Formation of DNA-network embedding ferromagnetic Cobalt nano-particles T. Kanki, Hidekazu. Tanaka, H. Shirakawa, Y. Sacho, M. Taniguchi, H. Lee, T. Kawai The Institute of Scientific and Industrial Research, Osaka University, Japan and Nam-Jung Kang, Jinwoo Chen Korea Advanced Institute of Science and Technology (KAIST), Korea DNA can be regarded as a naturally occurring and highly specific functional biopolymer and as a fine nano-wire. Moreover, it was found that large-scale DNA networks can be fabricated on mica surfaces. By using this network structure, we can expect to construct nano-scale assembly of functional nano particle, for example ferromagnetic Co nano particles, toward nano scale spin-electronics based on DNA circuits. When we formed DNA network by 250mg/ml DNA solution of poly(dG)-poly(dC) including ferromagnetic Co nano particles (diameter of 12nm), we have conformed the DNA network structure embedding Co nano-particles (height of about 12nm) by atomic force microscopy. On the other hand, we used 100mg/ml DNA solution, DNA can not connect each other, and many Co nano-particles exist without being embedded.

In-situ PXRD Study on the Annealing of SrFe12O19 Nano Particles

DEFF Research Database (Denmark)

Gjørup, Frederik; Saura-Múzquiz, Matilde; Christensen, Mogens

Nano sized strontium hexaferrite is synthesized using a hydrothermal flow synthesis, at temperature and pressure above waters critical point. The nano particles are hexagonal platelets, with the easy axis of magnetization along the short c-axis of the platelet. The nano powders are normally pressed...... and annealed to form mechanically stable pellets. This study uses In-situ Powder X-Ray Diffraction (PXRD) to examine the particle growth during annealing of the powder, with emphasis on the ratio between the axes of the platelets (a/c-ratio). By applying an external magnetic field before annealing......, the particles will align along the field lines of the external magnet, and the contact surfaces along the c-axis should increase. It will be examined whether the external magnetic field increases the growth along the c-axis relative to the a/b-axis, compared to annealing without prior magnetization....

Transferring metallic nano-island on hydrogen passivated silicon surface for nano-electronics

International Nuclear Information System (INIS)

Deng, J; Troadec, C; Joachim, C

2009-01-01

In a planar configuration, precise positioning of ultra-flat metallic nano-islands on semiconductor surface opens a way to construct nanostructures for atomic scale interconnects. Regular triangular Au nano-islands have been grown on atomically flat MoS 2 substrates and manipulated by STM to form nanometer gap metal-pads connector for single molecule electronics study. The direct assembly of regular shaped metal nano-islands on H-Si(100) is not achievable. Here we present how to transfer Au triangle nano-islands from MoS 2 onto H-Si(100) in a clean manner. In this experiment, clean MoS 2 substrates are patterned as array of MoS 2 pillars with height of 8 μm. The Au triangle nano-islands are grown on top of the pillars. Successful printing transfer of these Au nano-islands from the MoS 2 pillars to the H-Si(100) is demonstrated.

Nano materials Synthesis, Applications, and Toxicity 2012

International Nuclear Information System (INIS)

Nadagouda, M.N.; Lytle, D.A.; Speth, Th.F.; Dionysiou, D.D.; Mukhopadhyay, Sh.M.

2013-01-01

Nano technology presents new opportunities to create better materials and products. Nano materials find wide applications in catalysis, energy production, medicine, environmental remediation, automotive industry, and other sectors of our society. Nano material-containing products are already available globally and include automotive parts, defense application, drug delivery devices, coatings, computers, clothing, cosmetics, sports equipment, and medical devices. This special issue includes emerging advances in the field, with a special emphasis given to nano material synthesis and applications. There is an increasing interest in identifying magnetically separable catalysts for the degradation of wastewater. In this issue, A. Perumal et al. report an investigation of temperature-dependent magnetic properties and photo catalytic activity of CoFe 2 O 4 -Fe 3 O 4 magnetic nano composites (MNCs) synthesized by hydrothermal processes. These MNCs have saturation magnetization of 90 emu/g and coercivity (HC) of 530 Oe. The photo catalytic activity of the MNCs has been examined on the reduction of methyl orange (MO), a colored compound used in dyeing and printing textiles. The MNCs act as an excellent photo catalyst on the degradation of organic contaminants and degrade 93% of MO in 5 hours of UV irradiation. The photo catalytic activity of MNCs is attributed to remarkably high band gap energy and small particle size. Also, the MNCs with reproducible photo catalytic activity are easily separated from water media by applying an external magnetic field and they act as a promising catalyst for the remediation of textile wastewater. Microwaves can play an important role in orchestrating nano materials for a wide range of technological applications

Superconducting nano-strip particle detectors

International Nuclear Information System (INIS)

Cristiano, R; Ejrnaes, M; Casaburi, A; Zen, N; Ohkubo, M

2015-01-01

We review progress in the development and applications of superconducting nano-strip particle detectors. Particle detectors based on superconducting nano-strips stem from the parent devices developed for single photon detection (SSPD) and share with them ultra-fast response times (sub-nanosecond) and the ability to operate at a relatively high temperature (2–5 K) compared with other cryogenic detectors. SSPDs have been used in the detection of electrons, neutral and charged ions, and biological macromolecules; nevertheless, the development of superconducting nano-strip particle detectors has mainly been driven by their use in time-of-flight mass spectrometers (TOF-MSs) where the goal of 100% efficiency at large mass values can be achieved. Special emphasis will be given to this case, reporting on the great progress which has been achieved and which permits us to overcome the limitations of existing mass spectrometers represented by low detection efficiency at large masses and charge/mass ambiguity. Furthermore, such progress could represent a breakthrough in the field. In this review article we will introduce the device concept and detection principle, stressing the peculiarities of the nano-strip particle detector as well as its similarities with photon detectors. The development of parallel strip configuration is introduced and extensively discussed, since it has contributed to the significant progress of TOF-MS applications. (paper)

Electromagnetics of active coated nano-particles

DEFF Research Database (Denmark)

Arslanagic, Samel

2013-01-01

This work reviews the fundamental properties of several spherical and cylindrical active coated nano-particles excited by their respective single and/or multiple sources of radiation at optical frequencies. Particular attention is devoted to the influence of the source location and orientation, t......, the optical gain constant and the nano-particle material composition on the electric and magnetic near fields, the power flow density, the radiated power as well as the directivities. Resonant as well as quasi-transparent states will be emphasized in the discussion.......This work reviews the fundamental properties of several spherical and cylindrical active coated nano-particles excited by their respective single and/or multiple sources of radiation at optical frequencies. Particular attention is devoted to the influence of the source location and orientation...

Simulation, design and proof-of-concept of a two-stage continuous hydrothermal flow synthesis reactor for synthesis of functionalized nano-sized inorganic composite materials

DEFF Research Database (Denmark)

Zielke, Philipp; Xu, Yu; Simonsen, Søren Bredmose

2016-01-01

Computational fluid dynamics simulations were employed to evaluate several mixer geometries for a novel two-stage continuous hydrothermal flow synthesis reactor. The addition of a second stage holds the promise of allowing the synthesis of functionalized nano-materials as for example core-shell...... or decorated particles. Based on the simulation results, a reactor system employing a confined jet mixer in the first and a counter-flow mixer in the second stage was designed and built. The two-stage functionality and synthesis capacity is shown on the example of single- and two-stage syntheses of pure...... and mixed-phase NiO and YSZ particles....

Synthesis of Barium Titanate (BT) Nano Particles via Hydrothermal Route for the Production of BT-Polymer Nanocomposite

Science.gov (United States)

Habib, A.; Haubner, R.; Jakopic, G.; Stelzer, N.

2007-08-01

Barium titanate (high-k dielectric material) nano-powders (approx. 30 nm to 60 nm) were synthesised using hydrothermal route under moderate conditions. Effect of temperature and time was studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction techniques. Obtained barium titanate nano-powders were dispersed in thermoplastic polymethyl methacrylate (PMMA) to get homogeneous dispersions. Thin layers were obtained using these dispersions to achieve BaTiO3 endorsed polymer layers by dip-coating for improved polymer insulators on various substrates e.g., glass, and Au sputtered silicon wafers. SEM and focused ion beam (FIB) techniques were used to study the dispersion of barium titanate nano-particles in PMMA. The layers obtained showed homogenous distribution of BaTiO3 nano particles with no agglomeration.

Sol-Gel Synthesis and Characterization of Selected Transition Metal Nano-Ferrites

Directory of Open Access Journals (Sweden)

Aurelija GATELYTĖ

2011-09-01

Full Text Available In the present work, the sinterability and formation of nanosized yttrium iron garnet (Y3Fe5O12, yttrium perovskite ferrite (YFeO3, cobalt, nickel and zinc iron spinel (CoFe2O4, NiFe2O4 and ZnFe2O4, respectively powders by an aqueous sol-gel processes are investigated. The metal ions, generated by dissolving starting materials of transition metals in the diluted acetic acid were complexed by 1,2-ethanediol to obtain the precursors for the transition metal ferrite ceramics. The phase purity of synthesized nano-compounds was characterized by infrared spectroscopy (IR and powder X-ray diffraction analysis (XRD. The microstructural evolution and morphological features of obtained transition metal ferrites were studied by scanning electron microscopy (SEM.http://dx.doi.org/10.5755/j01.ms.17.3.598

Controlled synthesis of thorium and uranium oxide nano-crystals

International Nuclear Information System (INIS)

Hudry, Damien; Apostolidis, Christos; Walter, Olaf; Gouder, Thomas; Courtois, Eglantine; Kubel, Christian; Meyer, Daniel

2013-01-01

Very little is known about the size and shape effects on the properties of actinide compounds. As a consequence, the controlled synthesis of well-defined actinide-based nano-crystals constitutes a fundamental step before studying their corresponding properties. In this paper, we report on the non-aqueous surfactant-assisted synthesis of thorium and uranium oxide nano-crystals. The final characteristics of thorium and uranium oxide nano-crystals can be easily tuned by controlling a few experimental parameters such as the nature of the actinide precursor and the composition of the organic system (e.g., the chemical nature of the surfactants and their relative concentrations). Additionally, the influence of these parameters on the outcome of the synthesis is highly dependent on the nature of the actinide element (thorium versus uranium). By using optimised experimental conditions, monodisperse isotropic uranium oxide nano-crystals with different sizes (4.5 and 10.7 nm) as well as branched nano-crystals (overall size ca. 5 nm), nano-dots (ca. 4 nm) and nano-rods (with ultra-small diameters of 1 nm) of thorium oxide were synthesised. (authors)

Particle size studies to reveal crystallization mechanisms of the metal organic framework HKUST-1 during sonochemical synthesis.

Science.gov (United States)

Armstrong, Mitchell R; Senthilnathan, Sethuraman; Balzer, Christopher J; Shan, Bohan; Chen, Liang; Mu, Bin

2017-01-01

Systematic studies of key operating parameters for the sonochemical synthesis of the metal organic framework (MOF) HKUST-1(also called CuBTC) were performed including reaction time, reactor volume, sonication amplitude, sonication tip size, solvent composition, and reactant concentrations analyzed through SEM particle size analysis. Trends in the particle size and size distributions show reproducible control of average particle sizes between 1 and 4μm. These results along with complementary studies in sonofragmentation and temperature control were conducted to compare these results to kinetic crystal growth models found in literature to develop a plausible hypothetical mechanism for ultrasound-assisted growth of metal-organic-frameworks composed of a competitive mechanism including constructive solid-on-solid (SOS) crystal growth and a deconstructive sonofragmentation. Copyright © 2016 Elsevier B.V. All rights reserved.

Ion beam assisted synthesis of nano-crystals in glasses (silver and lead chalcogenides)

International Nuclear Information System (INIS)

Espiau de Lamaestre, R.

2005-04-01

This work deals with the interest in ion beams for controlling nano-crystals synthesis in glasses. We show two different ways to reach this aim, insisting on importance of redox phenomena induced by the penetration and implantation of ions in glasses. We first show that we can use the great energy density deposited by the ions to tailor reducing conditions, favorable to metallic nano-crystal precipitation. In particular, we show that microscopic mechanism of radiation induced silver precipitation in glasses are analogous to the ones of classical photography. Ion beams can also be used to overcome supersaturation of elements in a given matrix. In this work, we synthesized lead chalcogenide nano-crystals (PbS, PbSe, PbTe) whose optical properties are interesting for telecommunication applications. We demonstrate the influence of complex chalcogenide chemistry in oxide glasses, and its relationship with the observed loss of growth control when nano-crystals are synthesized by sequential implantation of Pb and S in pure silica. As a consequence of this understanding, we demonstrate a novel and controlled synthesis of PbS nano-crystals, consisting in implanting sulfur into a Pb-containing glass, before annealing. Choice of glass composition provides a better control of precipitation physico-chemistry, whereas the use of implantation allows high nano-crystal volume fractions to be reached. Our study of IR emission properties of these nano-crystals shows a very high excitation cross section, and evidence for a 'dark exciton' emitting level. (author)

Photoluminescence and magnetic properties of Fe-doped ZnS nano-particles synthesized by chemical co-precipitation

Energy Technology Data Exchange (ETDEWEB)

Nie Eryong; Liu Donglai; Zhang Yunsen; Bai Xue; Yi Liang; Jin Yong; Jiao Zhifeng [School of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China); Sun Xiaosong, E-mail: sunxs@scu.edu.cn [School of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China)

2011-08-15

This paper is focusing on the synthesis of Zn{sub 1-x}Fe{sub x}S nano-particles with x = 0, 0.1 and 0.2 by chemical co-precipitation method, the prepared of which are characterized by XRD, EDS, TEM, PL, magnetization versus field behavior and M-T curve. In the XRD patterns, Zn{sub 1-x}Fe{sub x}S nano-particles are shown of cubic zinc blende structure, and the broadening diffraction peaks consistent with the small-size characteristic of nano-materials. The diameter of nano-particles is between 3.3 and 5.5 nm according to the HR-TEM images. The EDS data confirm the existence of Fe ions in Fe-doped ZnS nanoparticles. There we found that Fe-doping did not import new energy bands or defect states, but reduced the intensity of PL peaks. The magnetization versus field behaviors were illustrated by the M-H curves at both 5 K and 300 K, respectively, where no remanence or coercive force was observed. This phenomenon indicates that the Zn{sub 1-x}Fe{sub x}S (x = 0.1) nano-particles are superparamagnetic. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves further reveal that the blocking temperature (T{sub B}) of the superparamagnetic behavior might be below 5 K.

Influence of Poly (Ethylene Glycol) and Oleylamine on the Formation of Nano to Micron Size Spherical SiO2 Particles

Science.gov (United States)

We report an eco-friendly synthesis of well–controlled, nano-to-micron-size, spherical SiO2 particles using non-hazardous solvent and a byproducts-producing system. It was found that the morphology and size of spherical SiO2 particles are controlled by adjusting the concentration...

PLGA/Nano-Zn O Composite Particles for Use in Biomedical Applications: Preparation, Characterization, and Antimicrobial Activity

International Nuclear Information System (INIS)

Stankovic, A.; Stevanovic, M.; Sezen, M.; Milenkovic, M.; Kaisarevic, S.; Andric, N.

2016-01-01

Copolymer poly (DL-lactide-co-glycolide) (PLGA) is extensively investigated for various biomedical applications such as controlled drug delivery or carriers in the tissue engineering. In addition, zinc oxide (Zn O) is widely used in biomedicine especially for materials like dental composites, as a constituent of creams for the treatment of a variety of skin irritations, to enhance the antibacterial activity of different medicaments and so on. Uniform, spherical Zn O nanoparticles (nano-Zn O) have been synthesized via microwave synthesis method. In addition to obtaining nano-Zn O, a further aim was to examine their immobilization in the PLGA polymer matrix (PLGA/nano-Zn O) and this was done by a simple physicochemical solvent/non solvent method. The samples were characterized by X-ray diffraction, scanning electron microscopy, laser diffraction particle size analyzer, differential thermal analysis, and thermal gravimetric analysis. The synthesized PLGA/nano-Zn O particles are spherical, uniform, and with diameters below 1μ. The influence of the different solvents and the drying methods during the synthesis was investigated too. The biocompatibility of the samples is discussed in terms of in vitro toxicity on human hepatoma HepG_2 cells by application of MTT assay and the antimicrobial activity was evaluated by broth micro dilution method against different groups of microorganisms (Gram-positive bacteria, Gram-negative bacteria, and yeast Candida albicans)

PLGA/Nano-ZnO Composite Particles for Use in Biomedical Applications: Preparation, Characterization, and Antimicrobial Activity

Directory of Open Access Journals (Sweden)

Ana Stanković

2016-01-01

Full Text Available Copolymer poly (DL-lactide-co-glycolide (PLGA is extensively investigated for various biomedical applications such as controlled drug delivery or carriers in the tissue engineering. In addition, zinc oxide (ZnO is widely used in biomedicine especially for materials like dental composites, as a constituent of creams for the treatment of a variety of skin irritations, to enhance the antibacterial activity of different medicaments and so on. Uniform, spherical ZnO nanoparticles (nano-ZnO have been synthesized via microwave synthesis method. In addition to obtaining nano-ZnO, a further aim was to examine their immobilization in the PLGA polymer matrix (PLGA/nano-ZnO and this was done by a simple physicochemical solvent/nonsolvent method. The samples were characterized by X-ray diffraction, scanning electron microscopy, laser diffraction particle size analyzer, differential thermal analysis, and thermal gravimetric analysis. The synthesized PLGA/nano-ZnO particles are spherical, uniform, and with diameters below 1 µm. The influence of the different solvents and the drying methods during the synthesis was investigated too. The biocompatibility of the samples is discussed in terms of in vitro toxicity on human hepatoma HepG2 cells by application of MTT assay and the antimicrobial activity was evaluated by broth microdilution method against different groups of microorganisms (Gram-positive bacteria, Gram-negative bacteria, and yeast Candida albicans.

Nano crystals-Related Synthesis, Assembly, and Energy Applications

International Nuclear Information System (INIS)

Dai, Q.; Hu, M.Z.; Yu, B.Z.; William, W.; Seo, J.

2011-01-01

Fundamental material properties have been dramatically altered in the nano scale regime because of quantum confinement effect. The unique size-tunable functionalities of nano materials make them involved in an extensive variety of energy applications, such as light-emitting diodes and solar cells. These applications have been demonstrated to cut energy consumption. In response to the ever-growing energy demands as well as the concerns of global warming, researchers are actively placing their enormous emphasis on the exploration of energy savings. During this exploration, the primary stage requires the design of appropriate strategies for the synthesis of high-quality nano crystals in terms of size uniformity and superior optical/electronic properties. Especially, there is a need to seek green-chemistry approaches for the synthesis of environmentally benign and user-friendly nano crystals. Another recent area of focus is the use of individual nano crystals as building blocks for self-assembly, providing new opportunities to improve the nano crystal performance

Microwave assisted synthesis of hydroxyapatite nano strips

Energy Technology Data Exchange (ETDEWEB)

Ruban Kumar, A.; Kalainathan, S.; Saral, A.M. [School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu (India)

2010-07-15

Synthesis of hydroxyapatite (HAP) nano strips was carried out by chemical precipitation method followed by microwave irradiation. The microwave assisted reactions proceed at fast rates. It is found that the presence of the complex reagent EDTA plays an important role in the morphological changes of nanostructure hydroxyapatite. EDTA acts as a hexadentate unit by wrapping itself around the Ca{sup 2+} metal ion with, four oxygen and two nitrogen atoms and forms several five member chelate rings. The relative specific surface energies associated with the facets of the crystal determines the shape of the crystal. Scanning electron microscopy revealed the presence of hydroxyapatite nano strips with the range 50-100 nm in EDTA influenced HAP powders. Fourier transform-infrared spectroscopy (FT-IR) result combined with the X-ray diffraction (XRD) indicates the presence of amorphous hydroxyapatite (HAP) in the as-prepared material. X-ray patterns collected on the powder after heat-treatment at 1100 C for 2 h in air exhibits single phase of HAP. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Study the scratch resistance of UV-cured epoxy acrylate in the presence of nano alumina particles via nano indentation

International Nuclear Information System (INIS)

Bastani, S.; Ebrahimi, M.; Kardar, P.

2007-01-01

In this research, an epoxy acrylate resin was synthesized, then the synthesized resin was used along with different multifunctional acrylate monomers and with a photoinitiator in different formulations and cured with UV radiation. The experiments were designed based on mixture method by using Design-Expert software. To investigate the effect of nano particles on the some of physical and mechanical properties of the UV cured resins, the suspension of nano alumina in TPGDA, was used in formulations. The hardness of prepared films was evaluated by using konig hardness tester and nano indentater. The scratch resistance and gloss of the films were also determined. The results showed that the visibility of scratch decreased when the nano particles were used. It seems that the self-healing property of the film improved in the presence of nano particles. The hardness of the samples with nano particles was found to be less than that the samples of without any nano particles. It was observed that the gloss of the films with the nano particles, almost was the same as the film without nano particles. (Author)

Direct Solid-State Conversion of Recyclable Metals and Alloys

Energy Technology Data Exchange (ETDEWEB)

Feng, Z; Manchiraju, K [Southwire Co.

2012-02-22

This project is to develop and demonstrate the concept feasibility of a highly energy-efficient solid-state material synthesis process, friction stir extrusion (FSE) technology. Specifically, the project seeks to explore and demonstrate the feasibility to recycle metals, produce nano-particle dispersion strengthened bulk materials and/or nano-composite materials from powders, chips or other recyclable feedstock metals or scraps through mechanical alloying and thermo-mechanical processing in a single-step. In this study, we focused on metal recycling, producing nano-engineered wires and evaluating their potential use in future generation long-distance electric power delivery infrastructure. More comprehensive R&D on the technology fundamentals and system scale-up toward early-stage applications in two targeted “showcase” fields of use: nano engineered bulk materials and Al recycling will be considered and planned as part of Project Continuation Plan.

Internal distribution of micro- / nano-sized inorganic particles and their cytocompatibility

Energy Technology Data Exchange (ETDEWEB)

Abe, Shigeaki; Iwadera, Nobuki; Esaki, Mitsue; Kida, Ikuhiro; Akasaka, Tsukasa; Uo, Motohiro; Yawaka, Yasutaka; Watari, Fumio [Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Mutoh, Mami [School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Morita, Manabu [Department of Oral Health, Okayama University Graduate School of Medicine, Dentisity and Pharmaceutical Science, Okayama 700-8525 (Japan); Haneda, Koichi [Department of Information Technology and Electronics, Senshu University of Ishinomaki, Ishinomaki 986-8580 (Japan); Yonezawa, Tetsu, E-mail: sabe@den.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

2011-10-29

Nano-sized materials have received much attention lately, both in terms of their multiple applications and their biocompatibility. From both viewpoints, understanding the biodistribution of administered nano-materials is very important. In this study, we succeeded in visualizing the biodistribution of administered nano-materials using a scanning X-ray analytical microscope and magnetic resonance imaging method. Quantitative observation was carried out by inductively coupled plasma - atomic emission spectroscopy. We observed that the administered nano-particles accumulated in the liver, lung and spleen of mice. To estimate their cytocompatibility, the nano-particles were exposed to human liver cells. The results suggested that the micro-/ nano- particles have good cytocompatibility, except for copper oxide nano-particles.

Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes

Energy Technology Data Exchange (ETDEWEB)

Dalmora, Adilson C. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Institute for Environmental Assessment and Water Studies (IDÆA), Spanish National Research Council (CSIC), C/Jordi Girona 18-26, 08034 Barcelona (Spain); Ramos, Claudete G.; Oliveira, Marcos L.S. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Teixeira, Elba C. [Fundação Estadual de Proteção Ambiental Henrique Luis Roessler, Porto Alegre, RS (Brazil); Kautzmann, Rubens M.; Taffarel, Silvio R. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Brum, Irineu A.S. de [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500. Bairro Agronomia. CEP: 91501-970 Porto Alegre, RS (Brazil); and others

2016-01-01

Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during “stonemeal” soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO{sub 2}, Al{sub 2}O{sub 3}, and Fe{sub 2}O{sub 3,} with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle

Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes

International Nuclear Information System (INIS)

Dalmora, Adilson C.; Ramos, Claudete G.; Oliveira, Marcos L.S.; Teixeira, Elba C.; Kautzmann, Rubens M.; Taffarel, Silvio R.; Brum, Irineu A.S. de

2016-01-01

Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during “stonemeal” soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO 2 , Al 2 O 3 , and Fe 2 O 3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical

One-Dimensional SnO2 Nano structures: Synthesis and Applications

International Nuclear Information System (INIS)

Pan, J.; Shen, H.; Mathur, S.; Pan, J.

2012-01-01

Nano scale semiconducting materials such as quantum dots (0-dimensional) and one-dimensional (1D) structures, like nano wires, nano belts, and nano tubes, have gained tremendous attention within the past decade. Among the variety of 1D nano structures, tin oxide (SnO 2 ) semiconducting nano structures are particularly interesting because of their promising applications in optoelectronic and electronic devices due to both good conductivity and transparence in the visible region. This article provides a comprehensive review of the recent research activities that focus on the rational synthesis and unique applications of 1D SnO 2 nano structures and their optical and electrical properties. We begin with the rational design and synthesis of 1D SnO 2 nano structures, such as nano tubes, nano wires, nano belts, and some heterogeneous nano structures, and then highlight a range of applications (e.g., gas sensor, lithium-ion batteries, and nano photonics) associated with them. Finally, the review is concluded with some perspectives with respect to future research on 1D SnO 2 nano structures

Nano-pyramid arrays for nano-particle trapping

NARCIS (Netherlands)

Sun, Xingwu; Veltkamp, Henk-Willem; Berenschot, Johan W.; Gardeniers, Johannes G.E.; Tas, Niels Roelof

2016-01-01

Abstract In this paper we present the drastic miniaturization of nano-wire pyramids fabricated by corner lithography. A particle trapping device was fabricated in a well-defined and symmetrical array. The entrance and exit hole-size can be tuned by adjusting fabrication parameters. We describe here

Editorial Emerging Multifunctional Nano structures

International Nuclear Information System (INIS)

Fan, H.; Lu, Y.; Ramanath, G.; Pomposo, J.A.

2009-01-01

The interest in emerging nano structures is growing exponentially since they are promising building blocks for advanced multifunctional nano composites. In recent years, an evolution from the controlled synthesis of individual monodisperse nanoparticles to the tailored preparation of hybrid spherical and also unsymmetrical multiparticle nano structures is clearly observed. As a matter of fact, the field of nano structures built around a nano species such as inside, outside, and next to a nanoparticle is becoming a new evolving area of research and development with potential applications in improved drug delivery systems, innovative magnetic devices, biosensors, and highly efficient catalysts, among several others Emerging nano structures with improved magnetic, conducting and smart characteristics are currently based on the design, synthesis, characterization and modeling of multifunctional nano object-based materials. In fact, core-shell nanoparticles and other related complex nano architectures covering a broad spectrum of materials (from metal and metal oxide to fused carbon, synthetic polymer, and bio polymer structures) to nano structure morphologies (spherical, cylindrical, star-like, etc.) are becoming the main building blocks for next generation of drug delivery systems, advanced sensors and biosensors, or improved nano composites. The five papers presented in this special issue examine the preparation and characterization of emerging multifunctional materials, covering from hybrid asymmetric structures to engineering nano composites.

Novel Composite Powders with Uniform TiB2 Nano-Particle Distribution for 3D Printing

Directory of Open Access Journals (Sweden)

Mengxing Chen

2017-03-01

Full Text Available It is reported that the ductility and strength of a metal matrix composite could be concurrently improved if the reinforcing particles were of the size of nanometers and distributed uniformly. In this paper, we revealed that gas atomization solidification could effectively disperse TiB2 nanoparticles in the Al alloy matrix due to its fast cooling rate and the coherent orientation relationship between TiB2 particles and α-Al. Besides, nano-TiB2 led to refined equiaxed grain structures. Furthermore, the composite powders with uniformly embedded nano-TiB2 showed improved laser absorptivity. The novel composite powders are well suited for selective laser melting.

Nano-sensing of the orientation of fluorescing molecules with active coated nano-particles

DEFF Research Database (Denmark)

Arslanagic, Samel; Ziolkowski, Richard W.

2015-01-01

The potential of using active coated nano-particles to determine the orientation of fluorescing molecules is reported. By treating each fluorescing molecule as an electric Hertzian dipole, single and multiple fluorescing molecules emitting coherently and incoherently in various orientations...... are considered in the presence of active coated nano-particles. It is demonstrated that in addition to offering a means to determine the orientation of a single molecule or the over-all orientation of the molecules surrounding it, the nature of the far-field response from the active coated nano...

Effect of nano-TiO{sub 2} particles size on the corrosion resistance of alkyd coating

Energy Technology Data Exchange (ETDEWEB)

Deyab, M.A., E-mail: hamadadeiab@yahoo.com; Keera, S.T.

2014-08-01

The coating system containing various sizes (∼10, 50, 100, 150 nm) of nano-TiO{sub 2} were prepared and investigated for corrosion protection of carbon steel in 1.0 M H{sub 2}SO{sub 4} using polarization, EIS and transmission electron microscopy (TEM) techniques. It was found that nano-TiO{sub 2} particles improved the corrosion resistance of alkyd coatings. The corrosion resistance occurs via physical adhesion on the metal surface. O{sub 2} and H{sub 2}O permeability of coating decreased with decrease in the nano-TiO{sub 2} size. The inhibition efficiency was found to increase with decreasing the size of nano-TiO{sub 2} and with decreasing the temperature. - Highlights: • Nano-TiO{sub 2} coating were prepared and used for corrosion protection of C-steel. • Nano-TiO{sub 2} particles in coating are effective to improve the corrosion resistance. • Nano-TiO{sub 2} coating inhibit both anodic and cathodic reactions. • Corrosion inhibition efficiency increases with decrease in the size of nano-TiO{sub 2}. • O{sub 2} and H{sub 2}O permeability of coating decreased with decrease in the nano-TiO{sub 2} size.

Infrared plasmonic nano-lasers based on Metal Insulator Metal waveguides

NARCIS (Netherlands)

Hill, M.T.

2010-01-01

We will present our latest results on metal-insulator-metal waveguide devices, in particular reducing the dimensions of devices and distributed feedback lasers. Also we will examine potential useful applications for metal nano-lasers.

Wear behaviour of A356 aluminium alloy reinforced with micron and nano size SiC particles

CSIR Research Space (South Africa)

Camagu, ST

2013-07-01

Full Text Available A method for producing metal matrix composites MMC was successfully implemented for mixing nano and low micron (“Hybrid”) sized SiC reinforcing particles in an aluminium alloy matrix. Due to the improved specific modulus and strength, MMC...

Gold nano-particles fixed on glass

International Nuclear Information System (INIS)

Worsch, Christian; Wisniewski, Wolfgang; Kracker, Michael; Rüssel, Christian

2012-01-01

Highlights: ► We produced wear resistant gold–ruby coatings on amorphous substrates. ► Thin sputtered gold layers were covered by or embedded in silica coatings. ► Annealing above T g of the substrate glass led to the formation of gold nano particles. ► A 1 1 1-texture of the gold particles is observed via XRD and EBSD. ► EBSD-patterns can be acquired from crystals covered by a thin layer of glass. - Abstract: A simple process for producing wear resistant gold nano-particle coatings on transparent substrates is proposed. Soda-lime-silica glasses were sputtered with gold and subsequently coated with SiO 2 using a combustion chemical vapor deposition technique. Some samples were first coated with silica, sputtered with gold and then coated with a second layer of silica. The samples were annealed for 20 min at either 550 or 600 °C. This resulted in the formation of round, well separated gold nano-particles with sizes from 15 to 200 nm. The color of the coated glass was equivalent to that of gold–ruby glasses. Silica/gold/silica coatings annealed at 600 °C for 20 min were strongly adherent and scratch resistant. X-ray diffraction and electron backscatter diffraction (EBSD) were used to describe the crystal orientations of the embedded particles. The gold particles are preferably oriented with their (1 1 1) planes perpendicular to the surface.

Making PMMA, PMA, PVAc and PSt nano particles using radiation

International Nuclear Information System (INIS)

Hidi, P.; Napper, D.H.; Sangster, D.F.

2000-01-01

Full text: During the last decade considerable research effort has been directed to making very small (10-50 nm diam.) nano size polymer particles. Most of the techniques described used more than one surfactant at high concentrations and resulted in relatively low polymer concentration. We have developed methods to make nano size polymer particles from methyl methacrylate (MMA), methyl acrylate (MA), vinyl acetat (Vac) and styrene (St) with a single anionic surfactant and gamma radiation. We succeeded in making nano particles in up to 15% concentration and with much higher polymer/ surfactant ratio than the earlier methods. With the radiation technique we can obtain high yield of polymer and can control the particle size of the polymer in the 2 S 2 0 8 ) instead of gamma irradiation. At present we prefer gamma initiation, because we have much better control and reproducibility of the exothermic polymerisation reaction, hence the critical parameters can be evaluated more accurately. We have started to use the different nano particles prepared for adsorption studies, as seeds for polymerisation and for making transparent gels with nano structure. We are also looking for other applications of the nano particles. It should be noted that the surface area of 1 gram of 20 nm diameter spheres is 300m 2

One-step flame synthesis of an active Pt/TiO2 catalyst for SO2 oxidation

DEFF Research Database (Denmark)

Johannessen, Tue; Koutsopoulos, Sotiris

2002-01-01

Flame synthesis as a route for production of composite metal oxides has been employed for the one-step synthesis of a supported noble metal catalyst, i.e. a Pt/TiO2 catalyst, by simultaneous combustion of Ti-isopropoxide and platinum acetylacetonate in a quench-cooled flame reactor. The average...... size of the platinum particles supported on aggregated nano-particles of TiO2 is approximately 2 nm. The high SO2-oxidation activity of the catalyst proves that platinum is not hidden in the titania matrix. The flame-produced catalyst showed catalytic activity similar to samples prepared by wet...

Optical Properties of Zinc Oxide Nano-particles Embedded in Dielectric Medium for UV region: Numerical Simulation

International Nuclear Information System (INIS)

Al-Hilli, S. M.; Willander, M.

2006-01-01

Zinc oxide nano-particles have been used by cosmetic industry for many years because they are extensively used as agents to attenuate (absorb and/or scatter) the ultraviolet radiation. In the most UV-attenuating agent is formulated in which the metal oxide nano-particles are incorporated into liquid media or polymer media are manufactured, such as sunscreens and skin care cosmetics. In this paper we study the wavelength dependence on the particle size (r eff = 10-100 nm) by solving the scattering problem of hexagonal ZnO particle for different shapes (plate, equal ratio, column) using the discrete dipole approximation method to find the absorption, scattering, and extinction efficiencies for the UV region (30-400 nm). A new modified hexagonal shape is introduced to determine the scattering problem and it is assumed in this study that the wavelength is comparable to the particle size. From these results, we conclude that the optimum particle radius to block the UV radiation is between r eff = 40-80 nm

Optical Properties of Zinc Oxide Nano-particles Embedded in Dielectric Medium for UV region: Numerical Simulation

Science.gov (United States)

Al-Hilli, S. M.; Willander, M.

2006-02-01

Zinc oxide nano-particles have been used by cosmetic industry for many years because they are extensively used as agents to attenuate (absorb and/or scatter) the ultraviolet radiation. In the most UV-attenuating agent is formulated in which the metal oxide nano-particles are incorporated into liquid media or polymer media are manufactured, such as sunscreens and skin care cosmetics. In this paper we study the wavelength dependence on the particle size ( r eff = 10-100 nm) by solving the scattering problem of hexagonal ZnO particle for different shapes (plate, equal ratio, column) using the discrete dipole approximation method to find the absorption, scattering, and extinction efficiencies for the UV region (30-400 nm). A new modified hexagonal shape is introduced to determine the scattering problem and it is assumed in this study that the wavelength is comparable to the particle size. From these results, we conclude that the optimum particle radius to block the UV radiation is between r eff = 40-80 nm.

Facile solid-state synthesis of oxidation-resistant metal nanoparticles at ambient conditions

Science.gov (United States)

Lee, Kyu Hyung; Jung, Hyuk Joon; Lee, Ju Hee; Kim, Kyungtae; Lee, Byeongno; Nam, Dohyun; Kim, Chung Man; Jung, Myung-Hwa; Hur, Nam Hwi

2018-05-01

A simple and scalable method for the synthesis of metal nanoparticles in the solid-state was developed, which can produce nanoparticles in the absence of solvents. Nanoparticles of coinage metals were synthesized by grinding solid hydrazine and the metal precursors in their acetates and oxides at 25 °C. The silver and gold acetates converted completely within 6 min into Ag and Au nanoparticles, respectively, while complete conversion of the copper acetate to the Cu sub-micrometer particles took about 2 h. Metal oxide precursors were also converted into metal nanoparticles by grinding alone. The resulting particles exhibit distinctive crystalline lattice fringes, indicating the formation of highly crystalline phases. The Cu sub-micrometer particles are better resistant to oxidation and exhibit higher conductivity compared to conventional Cu nanoparticles. This solid-state method was also applied for the synthesis of platinum group metals and intermetallic Cu3Au, which can be further extended to synthesize other metal nanoparticles.

Biomedical applications of green synthesized Nobel metal nanoparticles.

Science.gov (United States)

Khan, Zia Ul Haq; Khan, Amjad; Chen, Yongmei; Shah, Noor S; Muhammad, Nawshad; Khan, Arif Ullah; Tahir, Kamran; Khan, Faheem Ullah; Murtaza, Behzad; Hassan, Sadaf Ul; Qaisrani, Saeed Ahmad; Wan, Pingyu

2017-08-01

Synthesis of Nobel metal nanoparticles, play a key role in the field of medicine. Plants contain a substantial number of organic constituents, like phenolic compounds and various types of glycosides that help in synthesis of metal nanoparticles. Synthesis of metal nanoparticles by green method is one of the best and environment friendly methods. The major significance of the green synthesis is lack of toxic by-products produced during metal nanoparticle synthesis. The nanoparticles, synthesized by green method show various significant biological activities. Most of the research articles report the synthesized nanoparticles to be active against gram positive and gram negative bacteria. Some of these bacteria include Escherichia coli, Bacillus subtilis, Klebsiella pneumonia and Pseudomonas fluorescens. The synthesized nanoparticles also show significant antifungal activity against Trichophyton simii, Trichophyton mentagrophytes and Trichophyton rubrum as well as different types of cancer cells such as breast cancer cell line. They also exhibit significant antioxidant activity. The activities of these Nobel metal nano-particles mainly depend on the size and shape. The particles of small size with large surface area show good activity in the field of medicine. The synthesized nanoparticles are also active against leishmanial diseases. This research article explores in detail the green synthesis of the nanoparticles and their uses thereof. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis of Carbon Nano tubes Using Anadara Granosa Shells as Catalyst Support

International Nuclear Information System (INIS)

Mohd Zobir Hussein; Mohd Zobir Hussein; Salwani Asyikin Zakarya; Siti Halimah Sarijo

2011-01-01

The synthesis of carbon nano tubes (CNTs) by chemical vapor deposition (CVD) method using natural calcite prepared from Anadara granosa shells (CS), as metal catalyst support was studied. Hexane and iron were used as carbon precursor and catalyst, respectively. The as synthesised CNTs was characterized using XRD, TEM and FESEM. From the XRD patterns the CNTs peak can be seen more incisive after purification process and from the FESEM micrographs the CNTs can be seen as a bunch of rope-like structures. (author)

Optimizing critical heat flux enhancement through nano-particle-based surface modifications

International Nuclear Information System (INIS)

Truong, B.; Hu, L. W.; Buongiorno, J.

2008-01-01

Colloidal dispersions of nano-particles, also known as nano-fluids, have shown to yield significant Critical Heat Flux (CHF) enhancement. The CHF enhancement mechanism in nano-fluids is due to the buildup of a porous layer of nano-particles upon boiling. Unlike microporous coatings that had been studied extensively, nano-particles have the advantages of forming a thin layer on the substrate with surface roughness ranges from the sub-micron to several microns. By tuning the chemical properties it is possible to coat the nano-particles in colloidal dispersions onto the desired surface, as has been demonstrated in engineering thin film industry. Building on recent work conducted at MIT, this paper illustrates the maximum CHF enhancement that can be achieved based on existing correlations. Optimization of the CHF enhancement by incorporation of key factors, such as the surface wettability and roughness, will also be discussed. (authors)

Effect of nano size 3% wt TaC particles dispersion in two different metallic matrix composites

International Nuclear Information System (INIS)

Gomes, U.U.; Oliveira, L.A.; Souza, C.P.; Menezes, R.C.; Furukava, M.; Torres, Y.

2009-01-01

This work studies the characteristics of two different metallic matrixes composites, ferritic and austenitic steels, reinforced with 3% wt nano size tantalum carbide by powder metallurgy. The starting powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of the nano sized carbide dispersion on the matrix microstructures and its consequences on the mechanical properties were identified. The preliminary results showed that the sintering were influenced by morphology and the distribution of carbide and the alloys. (author)

Application of Iron Oxide Nano materials for the Removal of Heavy Metals

International Nuclear Information System (INIS)

Dave, P.N.; Chopda, L.V.

2014-01-01

In the 21st century water polluted by heavy metal is one of the environment problems. Various methods for removal of the heavy metal ions from the water have extensively been studied. Application of iron oxide nana particles based nano materials for removal of heavy metals is well-known adsorbents for remediation of water. Due to its important physiochemical property, inexpensive method and easy regeneration in the presence of external magnetic field make them more attractive toward water purification. Surface modification strategy of iron oxide nanoparticles is also used for the remediation of water increases the efficiency of iron oxide for the removal of the heavy metal ions from the aqueous system.

Synthesis of LaCoO{sub 3} nano-powders by aqueous gel-casting for intermediate temperature solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Cheng, Chia Siang; Zhang, Lan; Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore); Zhang, Yu.Jun [Key Lab for Liquid Structure and Heredity of Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan (China)

2008-04-15

LaCoO{sub 3} (LC) perovskite powders for intermediate temperature solid oxide fuel cells (IT-SOFCs) are synthesized by a simple and cost-effective aqueous gel-casting technique using metal nitrates as raw materials. Effect of the ratio of organic precursors (acrylamide (AM) monomer and N,N'-Methylenebisacrylamide (MBAM) crosslinker) to metal nitrates (lanthanum nitrate, cobalt nitrate) and the ratio of AM to MBAM on the particle size are investigated in detail. TEM results indicate that the particle size of LC nano-powders is in the range of 31-60 nm and decreases with increasing ratio of organic precursor to metal nitrates but is not affected by the ratio of AM to MBAM. Preliminary results show that the nano-structured electrode approach based on wet impregnation is effective to combine the high electrocatalytic activity of LC nano-powders and the structural stability of La{sub 0.72}Sr{sub 0.18}MnO{sub 3} {sub -} {sub {delta}} (LSM) electrodes for the development of IT-SOFC cathodes. (author)

Engineered nano particles: Nature, behavior, and effect on the environment.

Science.gov (United States)

Goswami, Linee; Kim, Ki-Hyun; Deep, Akash; Das, Pallabi; Bhattacharya, Satya Sundar; Kumar, Sandeep; Adelodun, Adedeji A

2017-07-01

Increased application of engineered nano particles (ENPs) in production of various appliances and consumer items is increasing their presence in the natural environment. Although a wide variety of nano particles (NPs) are ubiquitously dispersed in ecosystems, risk assessment guidelines to describe their ageing, direct exposure, and long-term accumulation characteristics are poorly developed. In this review, we describe what is known about the life cycle of ENPs and their impact on natural systems and examine if there is a cohesive relationship between their transformation processes and bio-accessibility in various food chains. Different environmental stressors influence the fate of these particles in the environment. Composition of solid media, pore size, solution chemistry, mineral composition, presence of natural organic matter, and fluid velocity are some environmental stressors that influence the transformation, transport, and mobility of nano particles. Transformed nano particles can reduce cell viability, growth and morphology, enhance oxidative stress, and damage DNA in living organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biosynthesis of Metal Nanoparticles: A Review

International Nuclear Information System (INIS)

Kulkarni, N.; Muddapur, U.

2014-01-01

The synthesis of nano structured materials, especially metallic nanoparticles, has accrued utmost interest over the past decade owing to their unique properties that make them applicable in different fields of science and technology. The limitation to the use of these nanoparticles is the paucity of an effective method of synthesis that will produce homogeneous size and shape nanoparticles as well as particles with limited or no toxicity to the human health and the environment. The biological method of nanoparticle synthesis is a relatively simple, cheap, and environmentally friendly method than the conventional chemical method of synthesis and thus gains an upper hand. The bio mineralization of nanoparticles in protein cages is one of such biological approaches used in the generation of nanoparticles. This method of synthesis apart from being a safer method in the production of nanoparticles is also able to control particle morphology.

Micro-nano filler metal foil on vacuum brazing of SiCp/Al composites

Science.gov (United States)

Wang, Peng; Gao, Zeng; Niu, Jitai

2016-06-01

Using micro-nano (Al-5.25Si-26.7Cu)- xTi (wt%, x = 1.0, 1.5, 2.0, 2.5 and 3.0) foils as filler metal, the research obtained high-performance joints of aluminum matrix composites with high SiC particle content (60 vol%, SiCp/Al-MMCs). The effect of brazing process and Ti content on joint properties was investigated, respectively. The experimental results indicate that void free dense interface between SiC particle and metallic brazed seam with C-Al-Si-Ti product was readily obtained, and the joint shear strength enhanced with increasing brazing temperature from 560 to 580 °C or prolonging soaking time from 10 to 90 min. Sound joints with maximum shear strength of 112.5 MPa was achieved at 580 °C for soaking time of 90 min with (Al-5.25Si-26.7Cu)-2Ti filler, where Ti(AlSi)3 intermetallic is in situ strengthening phase dispersed in the joint and fracture occured in the filler metal layer. In this research, the beneficial effect of Ti addition into filler metal on improving wettability between SiC particle and metallic brazed seam was demonstrated, and capable welding parameters were broadened for SiCp/Al-MMCs with high SiC particle content.

Rapid thermal melted TiO2 nano-particles into ZnO nano-rod and its application for dye sensitized solar cells

International Nuclear Information System (INIS)

Chao, Ching-Hsun; Chang, Chi-Lung; Chan, Chien-Hung; Lien, Shui-Yang; Weng, Ko-Wei; Yao, Kuo-Shan

2010-01-01

TiO 2 nano-particles with an anchored ZnO nano-rod structure were synthesized using the hydrothermal method to grow ZnO nano-rods and coated TiO 2 nano-particles on ZnO nano-rods using the rapid thermal annealing method on ITO conducting glass pre-coated with nano porous TiO 2 film. The XRD study showed that there was little difference in crystal composition for various types of TiO 2 nano-particles anchored to ZnO nano-rods. The as-prepared architecture was characterized using field-emission scanning electron microscopy (FE-SEM). Films with TiO 2 nano-particles anchored to ZnO nano-rods were used as electrode materials to fabricate dye sensitized solar cells (DSSCs). The best solar energy conversion efficiency of 2.397% was obtained by modified electrode material, under AM 1.5 illumination, achieved up to J sc = 15.382 mA/cm 2 , V oc = 0.479 V and fill factor = 32.8%.

Studying Of Preparation Silver Nano-Particles Using Spinning Disc Reactor

International Nuclear Information System (INIS)

Hoang Van Duc; Nguyen Thanh Chung; Tran Ngoc Ha; Ho Minh Quang; Nguyen Thi Thuc Phuong

2014-01-01

Preparation of silver nano-particles using spinning disc reactor has been investigated. The effects of technological factors and experimental conditions such as: concentrations of AgNO 3 , glucose, PVP, spinning speed, ect. on quality of nano-silver particles have been studied. With experimental conditions: rotation speed of 2000 rpm, weight rate of m PVP :m AgNO 3 = 1, AgNO 3 concentration of 0.01 M, glucose concentration of 0.02 M, silver particles of about 12 nm were obtained and the nano-silver solution were stable for more than 40 days. (author)

Method of producing carbon coated nano- and micron-scale particles

Science.gov (United States)

Perry, W. Lee; Weigle, John C; Phillips, Jonathan

2013-12-17

A method of making carbon-coated nano- or micron-scale particles comprising entraining particles in an aerosol gas, providing a carbon-containing gas, providing a plasma gas, mixing the aerosol gas, the carbon-containing gas, and the plasma gas proximate a torch, bombarding the mixed gases with microwaves, and collecting resulting carbon-coated nano- or micron-scale particles.

MD Simulation on Collision Behavior Between Nano-Scale TiO₂ Particles During Vacuum Cold Spraying.

Science.gov (United States)

Yao, Hai-Long; Yang, Guan-Jun; Li, Chang-Jiu

2018-04-01

Particle collision behavior influences significantly inter-nano particle bonding formation during the nano-ceramic coating deposition by vacuum cold spraying (or aerosol deposition method). In order to illuminate the collision behavior between nano-scale ceramic particles, molecular dynamic simulation was applied to explore impact process between nano-scale TiO2 particles through controlling impact velocities. Results show that the recoil efficiency of the nano-scale TiO2 particle is decreased with the increase of the impact velocity. Nano-scale TiO2 particle exhibits localized plastic deformation during collision at low velocities, while it is intensively deformed by collision at high velocities. This intensive deformation promotes the nano-particle adhesion rather than rebounding off. A relationship between the adhesion energy and the rebound energy is established for the bonding formation of the nano-scale TiO2 particle. The adhesion energy required to the bonding formation between nano-scale ceramic particles can be produced by high velocity collision.

Elaboration of silicon carbides nano particles (SiC): from the powder synthesis to the sintered ceramic

International Nuclear Information System (INIS)

Reau, A.

2008-01-01

Materials for the reactor cores of the fourth generation will need materials supporting high temperatures with fast neutrons flux. SiC f /SiC ceramics are proposed. One of the possible elaboration process is to fill SiC fiber piece with nano particles SiC powder and to strengthen by sintering. The aim of this thesis is to obtain a nano structured SiC ceramic as a reference for the SiC f /SiC composite development and to study the influence of the fabrication parameters. (A.L.B.)

Semiconductor-to-metallic flipping in a ZnFe2O4–graphene based smart nano-system: Temperature/microwave magneto-dielectric spectroscopy

International Nuclear Information System (INIS)

Ameer, Shahid; Gul, Iftikhar Hussain; Mahmood, Nasir; Mujahid, Muhammad

2015-01-01

Zn-(FeO 2 ) 2 –graphene smart nano-composites were synthesized using a novel modified solvothermal synthesis with different percentages of graphene. The structure of the nanocomposite was confirmed through X-ray diffraction, micro-Raman scattering spectroscopy, Ultraviolet–Visible spectroscopy, and Fourier transform infrared spectroscopy. The structural growth and morphological aspects were analyzed using scanning/transmission electron microscopy, revealing marvelous micro-structural features of the assembled nano-system resembling a maple leaf. To determine the composition, energy dispersive spectroscopy and X-ray photoelectron spectroscopy were used. Microwave magneto-dielectric spectroscopy revealed the improved dielectric properties of the nano-composite compared to those of the parent functional nanocrystals. Temperature gradient dielectric spectroscopy was used over the spectral range from 100 Hz to 5 MHz to reveal the phenomenological effect that the nanosystem flips from its usual semiconductor nature to a metallic nature with sensing temperature. Electrical conductivity and dielectric analysis indicated that the dielectric loss and the dielectric permittivity increased at room temperature. This extraordinary switching capability of the functionalized graphene nanosystem opens up a new dimension for engineering advanced and efficient smart composite materials. - Graphical abstract: Display Omitted - Highlights: • Zn-(FeO 2 ) 2 –graphene smart nano-composites were synthesized using a novel modified solvothermal synthesis. • The synthesized nano-system exhibits marvelous leaf like microstructure. • These nano-composites show improved magneto dielectric response. • This engineered smart nano-system shows phenomenological flipping from semiconductor like nature to metallic behavior

Visual Observation of Bubble Departure Characteristics in the Nano-particle Coated Heating Surface

International Nuclear Information System (INIS)

Han, Won Soek; Yoo, Shin; Lee, Jae Young

2010-01-01

Although the great enhancement of the thermal conductivity of the nanofluids, the fluid mixed with small amount of the nano meter sized particles, has been known, many experimental data of the boiling heat transfer reported degraded heat transfer rate than the fresh fluid. However, the great enhancement of the critical heat flux in nanofluids has been reported by many investigators. Due to the opaque scattering of the nano particles in nano fluids, direct observation of the bubble dynamics in the boiling process has not been made. However, it has been known that the boiling heat transfer characteristics of the heater coated by the nano particles in the fresh water are almost similar to that in the nano fluid. Recently, consensus has been made in the understanding of the CHF enhancement of nanofluids or nano-particle coated heater as the surface phenomena. Therefore, in the present paper, we do experimental study to observe the bubble departure in the pool boiling process with the nano-particle coated heater

[Effect of stability and dissolution of realgar nano-particles using solid dispersion technology].

Science.gov (United States)

Guo, Teng; Shi, Feng; Yang, Gang; Feng, Nian-Ping

2013-09-01

To improve the stability and dissolution of realgar nano-particles by solid dispersion. Using polyethylene glycol 6000 and poloxamer-188 as carriers, the solid dispersions were prepare by melting method. XRD, microscopic inspection were used to determine the status of realgar nano-particles in solid dispersions. The content and stability test of As(2)0(3) were determined by DDC-Ag method. Hydride generation atomic absorption spectrometry was used to determine the content of Arsenic and investigated the in vitro dissolution behavior of solid dispersions. The results of XRD and microscopic inspection showed that realgar nano-particles in solid dispersions were amorphous. The dissolution amount and rate of Arsenic from realgar nano-particles of all solid dispersions were increased significantly, the reunion of realgar nano-particles and content of As(2)0(3) were reduced for the formation of solid dispersions. The solid dispersion of realgar nano-particles with poloxamer-188 as carriers could obviously improve stability, dissolution and solubility.

Nano-magnetic particles used in biomedicine: core and coating materials.

Science.gov (United States)

Karimi, Z; Karimi, L; Shokrollahi, H

2013-07-01

Magnetic nanoparticles for medical applications have been developed by many researchers. Separation, immunoassay, drug delivery, magnetic resonance imaging and hyperthermia are enhanced by the use of suitable magnetic nanoparticles and coating materials in the form of ferrofluids. Due to their low biocompatibility and low dispersion in water solutions, nanoparticles that are used for biomedical applications require surface treatment. Various kinds of coating materials including organic materials (polymers), inorganic metals (gold, platinum) or metal oxides (aluminum oxide, cobalt oxide) have been attracted during the last few years. Based on the recent advances and the importance of nanomedicine in human life, this paper attempts to give a brief summary on the different ferrite nano-magnetic particles and coatings used in nanomedicine. Copyright © 2013 Elsevier B.V. All rights reserved.

Track-etch membranes enabled nano-/microtechnology: A review

International Nuclear Information System (INIS)

Chakarvarti, S.K.

2009-01-01

The art and science of fabricating structures with nano-/micrometric dimensions as well as precision is of the immense concern to any one investigating into nano-/microtechnology. The synergetic support of radiation and its potential in combining radiation effects with nano-/micromaterials has been recognized from the very early stages of nano-science research. In the myriad of applications and uses of nano-/microstructures, and nano particles in particular, from filtration, fabrication of biosensors, a chemical catalysis, magnetic structures, nano-electronics, MEMS, mechano-chemical conversion, quantum computing etc to name a few, radiation can play a significant role. One such potential application is track-etch membranes- a spin-off from the matter-radiation interaction. In the recent years, there has been a tremendous leap in the potential applications of metallic as well as non-metallic nano-/microstructures and materials. Nanotechnology has initiated a big hop and appears to be all set for bringing in revolution in the development and advancement of techniques involved in the synthesis and fabrication of sensors and devices. The conventional techniques for fabrication of very low dimensional wires - say quantum wires, include wet chemistry, electron beam lithography, focused ion beam techniques and atomic-beam lithography but for certain drawbacks and problems mentioned further. That has shown the ways for adopting newer alternative approaches which are relatively inexpensive, easier to handle and synergistically adorned with high efficacy. It is now well known that size of the devices and components dictate many unusual traits where quantum effects become more predominant. Quasi-one-dimensional nanostructures and materials like nanowires, fibres, tubules etc, having high aspect ratio would provide unusual and uncommon properties. Some properties like strength and hardness enhancement, dramatic changes in electrical conduction, field-ion-emission through

Track-etch membranes enabled nano-/microtechnology: A review

Energy Technology Data Exchange (ETDEWEB)

Chakarvarti, S.K., E-mail: skchakarvarti@gmail.co [Department of Physics, National Institute of Technology, Institution of National Importance, Kurukshetra 136 119 (India)

2009-10-15

The art and science of fabricating structures with nano-/micrometric dimensions as well as precision is of the immense concern to any one investigating into nano-/microtechnology. The synergetic support of radiation and its potential in combining radiation effects with nano-/micromaterials has been recognized from the very early stages of nano-science research. In the myriad of applications and uses of nano-/microstructures, and nano particles in particular, from filtration, fabrication of biosensors, a chemical catalysis, magnetic structures, nano-electronics, MEMS, mechano-chemical conversion, quantum computing etc to name a few, radiation can play a significant role. One such potential application is track-etch membranes- a spin-off from the matter-radiation interaction. In the recent years, there has been a tremendous leap in the potential applications of metallic as well as non-metallic nano-/microstructures and materials. Nanotechnology has initiated a big hop and appears to be all set for bringing in revolution in the development and advancement of techniques involved in the synthesis and fabrication of sensors and devices. The conventional techniques for fabrication of very low dimensional wires - say quantum wires, include wet chemistry, electron beam lithography, focused ion beam techniques and atomic-beam lithography but for certain drawbacks and problems mentioned further. That has shown the ways for adopting newer alternative approaches which are relatively inexpensive, easier to handle and synergistically adorned with high efficacy. It is now well known that size of the devices and components dictate many unusual traits where quantum effects become more predominant. Quasi-one-dimensional nanostructures and materials like nanowires, fibres, tubules etc, having high aspect ratio would provide unusual and uncommon properties. Some properties like strength and hardness enhancement, dramatic changes in electrical conduction, field-ion-emission through

Impact of nano and bulk ZrO2, TiO2 particles on soil nutrient contents and PGPR.

Science.gov (United States)

Karunakaran, Gopalu; Suriyaprabha, Rangaraj; Manivasakan, Palanisamy; Yuvakkumar, Rathinam; Rajendran, Venkatachalam; Kannan, Narayanasamy

2013-01-01

Currently, nanometal oxides are used extensively in different industries such as medicine, cosmetics and food. The increased consumption of nanoparticles (NPs) leads the necessity to understand the fate of the nanoparticles in the environment. The present study focused on the ecotoxicological behaviour of bulk and nano ZrO2 (Zirconia) and TiO2 (Titania) particles on PGPR (plant growth promoting rhizobacteria), soil and its nutrient contents. The microbial susceptibility study showed that nano TiO2 had 13 +/- 0.9 mm (B. megaterium), 15 +/- 0.2 mm (P. fluorescens), 16 +/- 0.2 mm (A. vinelandii) and 12 +/- 0.3 mm (B. brevis) zones of inhibition. However, nano and bulk ZrO2 particles were non-toxic to PGPR. In addition, it was found that toxicity varied depends on the medium of reaction. The soil study showed that nano TiO2 was found to be highly toxic, whereas bulk TiO2 was less toxic towards soil bacterial populations at 1000 mg L(-1). In contrast, nano and bulk ZrO2 were found to be inert at 1000 mg L(-1). The observed zeta potential and hydrophobicity of TiO2 particles causes more toxic than ZrO2 in parallel with particle size. However, nano TiO2 decreases the microbial population as well as nutrient level of the soil but not zirconia. Our finding shows that the mechanism of toxicity depends on size, hydrophobic potential and zeta potential of the metal oxide particles. Thus, it is necessary to take safety measures during the disposal and use of such toxic nanoparticles in the soil to prevent their hazardous effects.

Dynamics of magnetic nano-particle assembly

International Nuclear Information System (INIS)

Kondratyev, V N

2010-01-01

Ferromagnetically coupled nano-particle assembly is analyzed accounting for inter- and intra- particle electronic structures within the randomly jumping interacting moments model including quantum fluctuations due to the discrete levels and disorder. At the magnetic jump anomalies caused by quantization the magnetic state equation and phase diagram are found to indicate an existence of spinodal regions and critical points. Arrays of magnetized nano-particles with multiple magnetic response anomalies are predicted to display some specific features. In a case of weak coupling such arrays exhibit the well-separated instability regions surrounding the anomaly positions. With increasing coupling we observe further structure modification, plausibly, of bifurcation type. At strong coupling the dynamical instability region become wide while the stable regime arises as a narrow islands at small disorders. It is shown that exploring correlations of magnetic noise amplitudes represents convenient analytical tool for quantitative definition, description and study of supermagnetism, as well as self-organized criticality.

Sol-gel synthesis and characterisation of nano-scale hydroxyapatite

International Nuclear Information System (INIS)

Bilton, M; Brown, A P; Milne, S J

2010-01-01

Hydroxyapatite (HAp) forms the main mineral component of bone and teeth. This naturally occurring HAp is in the form of nano-metre sized crystallites of Ca 10 (PO 4 ) 6 (OH) 2 that contain a number of cation and anion impurities, for example CO 3 2- , F - , Na + , Mg 2+ and Sr 2+ . Synthetic nano-sized HAp particles exhibit favourable biocompatibility and bioactivity and in order to better match the composition to natural HAp there is great interest in producing a range of chemically modified powders. In this study, two HAp powders have been synthesised via a water-based low-temperature sol-gel method and a third, commercial powder from Sigma-Aldrich have been analysed. Subsequent powder calcination has been carried out within the temperature range of 500-700 0 C and the products characterised by bulk chemical analysis, X-ray diffraction and electron microscopy. Energy dispersive X-ray spectroscopy (EDX) in the TEM has been used to assess the composition of individual HAp particles. In order to do this accurately it is first necessary to account for the sensitivity of the HAp structure and composition to irradiation by the high energy electron beam of the TEM. This was done by monitoring the estimated Ca/P ratio derived from TEM-EDX of stoichiometric HAp under increasing levels of electron fluence. A fluence threshold (at a given beam energy) was established below which the measured Ca/P ratio can be considered to be stable. Subsequent elemental analysis at or below this threshold has enabled the variation in composition between particles both within and between synthesis batches to be accurately assessed. Compositional variability between particles is also evident, even in the commercial powder, but is far greater in the powders prepared by the sol-gel method.

In situ growth of metal particles on 3D urchin-like WO3 nanostructures.

Science.gov (United States)

Xi, Guangcheng; Ye, Jinhua; Ma, Qiang; Su, Ning; Bai, Hua; Wang, Chao

2012-04-18

Metal/semiconductor hybrid materials of various sizes and morphologies have many applications in areas such as catalysis and sensing. Various organic agents are necessary to stabilize metal nanoparticles during synthesis, which leads to a layer of organic compounds present at the interfaces between the metal particles and the semiconductor supports. Generally, high-temperature oxidative treatment is used to remove the organics, which can extensively change the size and morphology of the particles, in turn altering their activity. Here we report a facile method for direct growth of noble-metal particles on WO(3) through an in situ redox reaction between weakly reductive WO(2.72) and oxidative metal salts in aqueous solution. This synthetic strategy has the advantages that it takes place in one step and requires no foreign reducing agents, stabilizing agents, or pretreatment of the precursors, making it a practical method for the controlled synthesis of metal/semiconductor hybrid nanomaterials. This synthetic method may open up a new way to develop metal-nanoparticle-loaded semiconductor composites. © 2012 American Chemical Society

Preparation and Characterization of Pyrotechnics Binder-Coated Nano-Aluminum Composite Particles

Science.gov (United States)

Ye, Mingquan; Zhang, Shuting; Liu, Songsong; Han, Aijun; Chen, Xin

2017-07-01

The aim of this article is to protect the activity of nano-aluminum (Al) particles in solid rocket propellants and pyrotechnics. The morphology, structure, active aluminum content, and thermal and catalytic properties of the coated samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry-differential scanning calorimetry (TG-DSC), and oxidation-reduction titration methods. The results indicated that nano-Al particles could be effectively coated with phenolic resin (PF), fluororubber (Viton B), and shellac through a solvent/nonsolvent method. The energetic composite particles have core-shell structures and the thickness of the coating film is about 5-15 nm. Analysis of the active Al content revealed that Viton B coating had a much better protective effect. The TG-DSC results showed that the energy amount and energy release rate of PF-, Viton B-, and shellac-coated Al particles were larger than those of the raw nano-Al particles. The catalytic effects of coated Al particles on the thermal decomposition of ammonium perchlorate (AP) were better than those of raw nano-Al particles, and the effect of shellac-coated Al particles was significantly better than that of Viton B-coated Al particles.

Experimental study of metal nanoparticle synthesis by an arc evaporation/condensation process

International Nuclear Information System (INIS)

Förster, Henning; Wolfrum, Christian; Peukert, Wolfgang

2012-01-01

The generation of copper nanoparticles in an arc furnace by the evaporation/condensation method is systematically investigated. The evaporation/condensation process is advantageous because it allows direct synthesis using pure metals as starting materials avoiding reactions of expensive and potentially poisonous precursors. In the presented system, a transferred direct current arc provides the energy for evaporation of the metal target. In order to prevent an oxidation of the particles in the process, the synthesis is conducted in an atmosphere of inert gases (purity grade 5.0). The arc stability and its effect on particle synthesis are investigated. The experiments reveal excellent long-term arc stability for at least 8 h continuous operation delivering aerosols with high reproducibility (±10 % of average particle size). The influences of the arc current and length, the flow rates of the applied gases and the injection of hydrogen in the plasma zone on the particle size distributions and the agglomerate structure are studied. The produced copper nanoparticles are characterized by scanning mobility particle sizing and scanning electron microscopy. The average particle size could be well controlled in a size range 4–50 nm by selecting appropriate operating parameters.

Green Synthesis of Silver Nanoparticles Using Pinus eldarica Bark Extract

Directory of Open Access Journals (Sweden)

Siavash Iravani

2013-01-01

Full Text Available Recently, development of reliable experimental protocols for synthesis of metal nanoparticles with desired morphologies and sizes has become a major focus of researchers. Green synthesis of metal nanoparticles using organisms has emerged as a nontoxic and ecofriendly method for synthesis of metal nanoparticles. The objectives of this study were production of silver nanoparticles using Pinus eldarica bark extract and optimization of the biosynthesis process. The effects of quantity of extract, substrate concentration, temperature, and pH on the formation of silver nanoparticles are studied. TEM images showed that biosynthesized silver nanoparticles (approximately in the range of 10–40 nm were predominantly spherical in shape. The preparation of nano-structured silver particles using P. eldarica bark extract provides an environmentally friendly option, as compared to currently available chemical and/or physical methods.

Synthesis, Characterization and Application of Nano Lepidocrocite ...

African Journals Online (AJOL)

NICO

Degradation of halogenated organic compounds using nanoparticles is one of the innovative ... way as the synthesis of nano zero-valent iron by using sodium .... +. −. 2и High. 2и Low. FWHM. Crystallite. /counts. /counts. /degree. /degree.

Impact of the Excitation Source and Plasmonic Material on Cylindrical Active Coated Nano-Particles

DEFF Research Database (Denmark)

Arslanagic, Samel; Liu, Yan; Malureanu, Radu

2011-01-01

Electromagnetic properties of cylindrical active coated nano-particles comprised of a silica nano-cylinder core layered with a plasmonic concentric nano-shell are investigated for potential nano-sensor applications. Particular attention is devoted to the near-field properties of these particles...

Nano-objects emitted during maintenance of common particle generators: direct chemical characterization with aerosol mass spectrometry and implications for risk assessments

Energy Technology Data Exchange (ETDEWEB)

Nilsson, Patrik T., E-mail: patrik.nilsson@design.lth.se; Isaxon, Christina [Lund University, Ergonomics and Aerosol Technology (Sweden); Eriksson, Axel C. [Lund University, Nuclear Physics (Sweden); Messing, Maria E. [Lund University, Solid State Physics (Sweden); Ludvigsson, Linus; Rissler, Jenny [Lund University, Ergonomics and Aerosol Technology (Sweden); Hedmer, Maria; Tinnerberg, Håkan [Lund University, Division of Occupational and Environmental Medicine, Department of Laboratory Medicine (Sweden); Gudmundsson, Anders [Lund University, Ergonomics and Aerosol Technology (Sweden); Deppert, Knut [Lund University, Solid State Physics (Sweden); Bohgard, Mats; Pagels, Joakim H. [Lund University, Ergonomics and Aerosol Technology (Sweden)

2013-11-15

Nanotechnology gives us materials with enhanced or completely new properties. At the same time, inhalation of manufactured nano-objects has been related to an array of adverse biological effects. We characterized particle emissions, which occurred during maintenance of common metal nanoparticle generators and contrasted the properties of the emitted particles with those originally produced by the generators. A new approach using online aerosol mass spectrometry (AMS), for time- and size-resolved measurements of the particle chemical composition, was applied in combination with more conventional techniques for particle sampling and analysis, including electron microscopy. Emissions during maintenance work, in terms of mass and surface area concentration in the size range of 0.02–10 μm, were dominated by large agglomerates (1–5 μm). With AMS, we show that the particle composition depends on both generator type and maintenance task being performed and that the instrument can be used for highly time-resolved selective studies of metal nanoparticle emissions. The emitted agglomerates have a relatively high probability to be deposited in the lower respiratory tract, since the mean particle diameter coincided with a peak in the lung deposition curve. Each of these agglomerates consisted of a very high number (10{sup 3}–10{sup 5}/agglomerate) of nanometer-sized primary particles originating from the particle synthesis process. This made them possess large surface areas, one of the key properties in nanotoxicology. Similar agglomerates may be emitted in a wide range of processes when nanoparticles are manufactured or handled. The fate of such agglomerates, once deposited in the respiratory tract, is unknown and should therefore be considered in future particle toxicological studies. Our results highlight the importance of including micrometer-sized particles in exposure and emission assessments.

Nano-objects emitted during maintenance of common particle generators: direct chemical characterization with aerosol mass spectrometry and implications for risk assessments

International Nuclear Information System (INIS)

Nilsson, Patrik T.; Isaxon, Christina; Eriksson, Axel C.; Messing, Maria E.; Ludvigsson, Linus; Rissler, Jenny; Hedmer, Maria; Tinnerberg, Håkan; Gudmundsson, Anders; Deppert, Knut; Bohgard, Mats; Pagels, Joakim H.

2013-01-01

Nanotechnology gives us materials with enhanced or completely new properties. At the same time, inhalation of manufactured nano-objects has been related to an array of adverse biological effects. We characterized particle emissions, which occurred during maintenance of common metal nanoparticle generators and contrasted the properties of the emitted particles with those originally produced by the generators. A new approach using online aerosol mass spectrometry (AMS), for time- and size-resolved measurements of the particle chemical composition, was applied in combination with more conventional techniques for particle sampling and analysis, including electron microscopy. Emissions during maintenance work, in terms of mass and surface area concentration in the size range of 0.02–10 μm, were dominated by large agglomerates (1–5 μm). With AMS, we show that the particle composition depends on both generator type and maintenance task being performed and that the instrument can be used for highly time-resolved selective studies of metal nanoparticle emissions. The emitted agglomerates have a relatively high probability to be deposited in the lower respiratory tract, since the mean particle diameter coincided with a peak in the lung deposition curve. Each of these agglomerates consisted of a very high number (10 3 –10 5 /agglomerate) of nanometer-sized primary particles originating from the particle synthesis process. This made them possess large surface areas, one of the key properties in nanotoxicology. Similar agglomerates may be emitted in a wide range of processes when nanoparticles are manufactured or handled. The fate of such agglomerates, once deposited in the respiratory tract, is unknown and should therefore be considered in future particle toxicological studies. Our results highlight the importance of including micrometer-sized particles in exposure and emission assessments

Can Nano-Particle Melt below the Melting Temperature of Its Free Surface Partner?

International Nuclear Information System (INIS)

Sui Xiao-Hong; Qin Shao-Jing; Wang Zong-Guo; Kang Kai; Wang Chui-Lin

2015-01-01

The phonon thermal contribution to the melting temperature of nano-particles is inspected. The discrete summation of phonon states and its corresponding integration form as an approximation for a nano-particle or for a bulk system have been analyzed. The discrete phonon energy levels of pure size effect and the wave-vector shifts of boundary conditions are investigated in detail. Unlike in macroscopic thermodynamics, the integration volume of zero-mode of phonon for a nano-particle is not zero, and it plays an important role in pure size effect and boundary condition effect. We find that a nano-particle will have a rising melting temperature due to purely finite size effect; a lower melting temperature bound exists for a nano-particle in various environments, and the melting temperature of a nano-particle with free boundary condition reaches this lower bound. We suggest an easy procedure to estimation the melting temperature, in which the zero-mode contribution will be excluded, and only several bulk quantities will be used as input. We would like to emphasize that the quantum effect of discrete energy levels in nano-particles, which is not present in early thermodynamic studies on finite size corrections to melting temperature in small systems, should be included in future researches. (condensed matter: structural, mechanical, and thermal properties)

Application of ionizing radiation for metal nanoclusters synthesis

International Nuclear Information System (INIS)

Smietanko-Chmielewska, D.K.; Chmielewski, A.G.; Warsaw University of Technology, Warsaw

2011-01-01

Complete text of publication follows. Possibility of ionizing radiation application in nanotechnology has been observed from very beginning when this field of science and technology was named. The lithography is based on electron and ion beam applications, and metal clusters synthesis by radiation induced radicals was reported many years ago. International Atomic Energy Agency was the first organization which has started coordinated programs on radiation applications in nanotechnology which are being continued in the frame of regional cooperation project RER8014. Some of applications led to patented technical solutions. Then review papers and chapters in the books have been published. The main applications beside of lithography deal with metal nanoclusters and nano-composites synthesis. Polymer composites containing metal nanoparticles have attracted a great interest due to their unique chemical and physical properties. 'Green' chemistry promotes application of natural fibers in such structures, among them cellulose is one of the most frequently used. However, cellulose fabric have ability to absorb moisture, so under certain conditions of humidity and temperature they can be subjected to microbial attack. One of the most popular and best known antibacterial agents is silver, which serves as a potential antibacterial material acting against an exceptionally broad spectrum of bacteria including activity against antibiotic-resistant bacteria. Silver nanoparticles (Ag NPs) were grown at the cellulose fibers surface by direct reduction of AgNO 3 with electron beam (EB) application. The big field of development concerns nano composites, possibility of e/X units application enlarge this possibility to industrial scale product manufacturing. Acknowledgement: This work was supported by the IAEA, regional project RER/8/014 and by the Ministry of Science and Higher Education, project DPN/W14/IAEA/2009.

Nano crystals-Related Synthesis, Assembly, and Energy Applications 2012

International Nuclear Information System (INIS)

Zou, B.; Yu, W.W.; Seo, J.; Zhu, T.; Hu, M.Z.

2012-01-01

During the past decades, nano crystals have attracted broad attention due to their unique shape- and size-dependent physical and chemical properties that differ drastically from their bulk counterparts. Hitherto, much effort has been dedicated to achieving rational controlling over the morphology, assembly, and related energy applications of the nano materials. Therefore, the ability to manipulate the morphology, size, and size distribution of inorganic nano materials is still an important goal in modern materials physics and chemistry. Especially, the world's demand for energy supply is causing a dramatic escalation of social and political unrest. Likewise, the environmental impact of the global climate change due to the combustion of fossil fuel is becoming increasingly alarming. These problems compel us to search for effective routes to build devices that can supply sustainable energy, with not only high efficiency but also environmental friendship. One of ways to relieve the energy crisis is to exploit devices based on renewable energy sources, such as solar energy and water power. Aiming at this exploration, the primary stage requires the design of appropriate strategies for the synthesis of high-quality nano crystals with respect to size uniformity and superior electrochemical performances. As a consequence, we organize the current special issue for Journal of Nano materials to provide the authors with a platform and readers with the latest achievements of nano crystals-related synthesis, assembly, and energy applications.

Max–min Bin Packing Algorithm and its application in nano-particles filling

International Nuclear Information System (INIS)

Zhu, Dingju

2016-01-01

With regard to existing bin packing algorithms, higher packing efficiency often leads to lower packing speed while higher packing speed leads to lower packing efficiency. Packing speed and packing efficiency of existing bin packing algorithms including NFD, NF, FF, FFD, BF and BFD correlates negatively with each other, thus resulting in the failure of existing bin packing algorithms to satisfy the demand of nano-particles filling for both high speed and high efficiency. The paper provides a new bin packing algorithm, Max–min Bin Packing Algorithm (MM), which realizes both high packing speed and high packing efficiency. MM has the same packing speed as NFD (whose packing speed ranks no. 1 among existing bin packing algorithms); in case that the size repetition rate of objects to be packed is over 5, MM can realize almost the same packing efficiency as BFD (whose packing efficiency ranks No. 1 among existing bin packing algorithms), and in case that the size repetition rate of objects to be packed is over 500, MM can achieve exactly the same packing efficiency as BFD. With respect to application of nano-particles filling, the size repetition rate of nano particles to be packed is usually in thousands or ten thousands, far higher than 5 or 500. Consequently, in application of nano-particles filling, the packing efficiency of MM is exactly equal to that of BFD. Thus the irreconcilable conflict between packing speed and packing efficiency is successfully removed by MM, which leads to MM having better packing effect than any existing bin packing algorithm. In practice, there are few cases when the size repetition of objects to be packed is lower than 5. Therefore the MM is not necessarily limited to nano-particles filling, and can also be widely used in other applications besides nano-particles filling. Especially, MM has significant value in application of nano-particles filling such as nano printing and nano tooth filling.

Control of cancer growth using single input autonomous fuzzy Nano-particles

Directory of Open Access Journals (Sweden)

Fahimeh Razmi

2015-04-01

Full Text Available In this paper a single input fuzzy controller is applied on autonomous drug-encapsulated nanoparticles (ADENPs to restrict the cancer growth. The proposed ADENPs, swarmly release the drug in local cancerous tissue and effectively decreases the destruction of normal tissue. The amount of released drug is defined considering to feed backed values of tumor growth rate and the used drug. Some significant characteristics of Nano particles compared to Nano-robots is their ability to recognize the cancerous tissue from the normal one and their simple structure. Nano particles became an attractive topic in Nano science and many efforts have been done to manufacture these particles. Simulation results show that the proposed controlling method not only decreases the cancerous tissue effectively but also reduces the side effects of drug impressively.

Characterization of nano structured metallic materials; Caracterizacion de materiales metalicos nanoestructurados

Energy Technology Data Exchange (ETDEWEB)

Marin A, M.; Gutierrez W, C.; Cruz C, R.; Angeles C, C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

1997-07-01

Nowadays the search of new materials with specific optical properties has carried out to realize a series of experiments through the polymer synthesis [(C{sub 3}N{sub 3}){sub 2} (NH){sub 3}]{sub n} doped with gold metallic nanoparticles. The thermal stability of a polymer is due to the presence of tyazine rings contained in the structure. The samples were characterized by High Resolution Transmission Electron Microscopy, X-ray diffraction by the Powder method, Ft-infrared and its thermal properties by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA). One of the purposes of this work is to obtain nano structured materials over a polymeric matrix. (Author)

Evaluation of minimum quantity lubrication grinding with nano-particles and recent related patents.

Science.gov (United States)

Li, Changhe; Wang, Sheng; Zhang, Qiang; Jia, Dongzhou

2013-06-01

In recent years, a large number of patents have been devoted to developing minimum quantity lubrication (MQL) grinding techniques that can significantly improve both environmentally conscious and energy saving and costeffective sustainable grinding fluid alternatives. Among them, one patent is about a supply system for the grinding fluid in nano-particle jet MQL, which produced MQL lubricant by adding solid nano-particles in degradable grinding fluid. The MQL supply device turns the lubricant to the pulse drops with fixed pressure, unchanged pulse frequency and the same drop diameter. The drops will be produced and injected in the grinding zone in the form of jet flow under high pressure gas and air seal. As people become increasingly demanding on our environment, minimum quantity lubrication has been widely used in the grinding and processing. Yet, it presents the defect of insufficient cooling performance, which confines its development. To improve the heat transfer efficiency of MQL, nano-particles of a certain mass fraction can be added in the minimum quantity of lubricant oil, which concomitantly will improve the lubrication effects in the processing. In this study, the grinding experiment corroborated the effect of nano-particles in surface grinding. In addition, compared with other forms of lubrication, the results presented that the grinding force, the friction coefficient and specific grinding energy of MQL grinding have been significantly weakened, while G ratio greatly rose. These are attributed to the friction oil-film with excellent anti-friction and anti-wear performance, which is generated nano-particles at the wheel/workpiece interface. In this research, the cooling performance of nano-particle jet MQL was analyzed. Based on tests and experiments, the surface temperature was assayed from different methods, including flood lubricating oil, dry grinding, MQL grinding and nano-particle jet MQL grinding. Because of the outstanding heat transfer

Transparent electrode designs based on optimal nano-patterning of metallic films

KAUST Repository

Catrysse, Peter B.; Fan, Shanhui

2010-01-01

, such as indium tin oxide, are commonly used. There is substantial interest in replacing them, however, motivated by practical problems and recent discoveries regarding the optics of nano-patterned metals. When designing nano-patterned metallic films for use

Preliminary Study of Fermented Tapioca for Synthesis of Carbon Nano tubes

International Nuclear Information System (INIS)

Nurulhuda Ismail; Ying, P.Y.

2011-01-01

Carbon nano tubes had been produced by various precursor such as gas (methane, carbon dioxide), oil (camphor oil, olive oil, and cooking oil) and alcohol. Different methods used for carbon nano tubes synthesis like arc discharge method, laser ablation method and chemical vapour deposition method. In this experiment, thermal chemical vapour deposition method was selected for carbon nano tubes synthesis. Starting material of fermented tapioca was used as carbon source for the process. Argon gas flow were controlled at around 10-15 bubbles per minute and deposition time around 20 to 30 minute. Others parameters such as temperature of furnace 1 and 2, amount of inoculum and catalyst have been studied. The asThermogravimetri (TGA) was used to determine the volatile temperature of the mixing catalyst and fermented tapioca extract. The grown carbon nano tubes morphology was characterized through Raman spectroscopy, scanning and Field Emission Scanning Electron Microscopy (FESEM) techniques. The surface morphology and uniformity of carbon nano tubes are reliant to parameters used. (author)

Ductility and work hardening in nano-sized metallic glasses

Energy Technology Data Exchange (ETDEWEB)

Chen, D. Z., E-mail: dzchen@caltech.edu [Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, California 91125 (United States); Gu, X. W. [Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States); An, Q.; Goddard, W. A. [Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 (United States); Greer, J. R. [Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, California 91125 (United States); The Kavli Nanoscience Institute, California Institute of Technology, Pasadena, California 91125 (United States)

2015-02-09

In-situ nano-tensile experiments on 70 nm-diameter free-standing electroplated NiP metallic glass nanostructures reveal tensile true strains of ∼18%, an amount comparable to compositionally identical 100 nm-diameter focused ion beam samples and ∼3 times greater than 100 nm-diameter electroplated samples. Simultaneous in-situ observations and stress-strain data during post-elastic deformation reveal necking and work hardening, features uncharacteristic for metallic glasses. The evolution of free volume within molecular dynamics-simulated samples suggests a free surface-mediated relaxation mechanism in nano-sized metallic glasses.

Towards quantitative analysis of core-shell catalyst nano-particles by aberration corrected high angle annular dark field STEM and EDX

International Nuclear Information System (INIS)

Haibo, E; Nellist, P D; Lozano-Perez, S; Ozkaya, D

2010-01-01

Core-shell structured heterogeneous catalyst nano-particles offer the promise of more efficient precious metal usage and also novel functionalities but are as yet poorly characterised due to large compositional variations over short ranges. High angle annular dark field detector in a scanning transmission electron microscope is frequently used to image at high resolution because of its Z-contrast and incoherent imaging process, but generally little attention is paid to quantification. Energy dispersive X-ray analysis provides information on thickness and chemical composition and, used in conjunction with HAADF-STEM, aids interpretation of imaged nano-particles. We present important calibrations and initial data for truly quantitative high resolution analysis.

Formulation of nano-ceramic filters used in separation of heavy metals . Part II: Zirconia ceramic filters

International Nuclear Information System (INIS)

Khalil, T.; Labib, Sh.; Abou EI-Nour, F.H.; Abdel-Kbalik, M.

2007-01-01

Zirconia ceramic filters are prepared using polymeric sol-gel process. An optimization of synthesis parameters was studied to give cracked free coated nano porous film with high performance quality. Zirconia ceramic filters are characterized to select tbe optimized conditions that give tbe suitable zirconia filter used in heavy metal separation. The ceramic filters were characterized using BET method for surface measurements, mercury porosimeter for pore size distribution analysis and coating thickness measurements, SEM for microstructural studies and atomic absorption spectrophotometer (AAS) for metal analysis. The results indicated that zirconia ceramic filters. show high separation performance for cadmium, cupper, iron, manganese and lead

Impact of the Excitation Source and Plasmonic Material on Cylindrical Active Coated Nano-Particles

Directory of Open Access Journals (Sweden)

Richard W. Ziolkowski

2011-09-01

Full Text Available Electromagnetic properties of cylindrical active coated nano-particles comprised of a silica nano-cylinder core layered with a plasmonic concentric nano-shell are investigated for potential nano-sensor applications. Particular attention is devoted to the near-field properties of these particles, as well as to their far-field radiation characteristics, in the presence of an electric or a magnetic line source. A constant frequency canonical gain model is used to account for the gain introduced in the dielectric part of the nano-particle, whereas three different plasmonic materials (silver, gold, and copper are employed and compared for the nano-shell layers.

Biomimetic composite microspheres of collagen/chitosan/nano-hydroxyapatite: In-situ synthesis and characterization.

Science.gov (United States)

Teng, Shu-Hua; Liang, Mian-Hui; Wang, Peng; Luo, Yong

2016-01-01

The collagen/chitosan/hydroxyapatite (COL/CS/HA) composite microspheres with a good spherical form and a high dispersity were successfully obtained using an in-situ synthesis method. The FT-IR and XRD results revealed that the inorganic phase in the microspheres was crystalline HA containing carbonate ions. The morphology of the composite microspheres was dependent on the HA content, and a more desirable morphology was achieved when 20 wt.% HA was contained. The composite microspheres exhibited a narrow particle distribution, most of which ranged from 5 to 10 μm. In addition, the needle-like HA nano-particles were uniformly distributed in the composite microspheres, and their crystallinity and crystal size decreased with the HA content. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis of Carbon nano structures by plasma discharge; Sintesis de nanoestructuras de carbono por descarga de plasmaa

Energy Technology Data Exchange (ETDEWEB)

Jimenez L, M L

2007-07-01

Due to the great quantity of applications of the carbon nano structures (NEC) in diverse areas like: synthesis of super-resistant materials, hydrogen storage, nano sensors generation and nano catalysts, it has seen the necessity to generate new processes of synthesis of this materials as well as to already improve those existent. The present work has as objective to optimize the NEC synthesis process by means of the electric arc method which uses alternating current to high frequencies (HF), obtaining relatively clean products; that is to say, it hardly presents amorphous material neither sludges. They stand out the obtaining of carbon nano fibers (NFC) by means of a luminescent-arch discharge, in a gas mixture of He-CH{sub 4} with 34% at. Ni/10.32% at.Y like catalyst; at a frequency of 42 kHz and low power (300 W). This method benefits the amass of the particles in both electrodes due to the high frequencies. The time of duration of the process oscillates between 5 and 20 minutes. The obtained product was characterized by scanning electron microscopy (MEB), transmission electron microscopy (MET) to determine the NEC type obtained and by X-ray diffraction analysis and Raman spectroscopy for determining the purity of the samples. The NFC is relatively free of amorphous coal. The surface and structural analysis indicates that the fibers have a half diameter of 80 nm. It is also made, a study by optical emission spectroscopy of plasma using the Swan band for determining the temperature. (Author)

Photopyroelectric Techniques for thermo-optical characterization of gold nano-particles

International Nuclear Information System (INIS)

Chávez-Sandoval, B E; Balderas-López, J A; Padilla-Bernal, G; Moreno-Rivera, M A; Franco-Hernández, M O; Martínez-Jiménez, A; García-Franco, F

2015-01-01

Since the first methodology, proposed by Turkevich, to produce gold nanoparticles (AuNPs), improvements have been made as to allow better controllability in their size and shape. These two parameters play important role for application of gold nanoparticles since they determine their optical and thermal properties. Two photopyroelectric techniques for the measurement of the thermal diffusivity and the optical absorption coefficient for nano-particles are introduced. These thermo-physical properties were measured for the colloidal systems at different nano-particle's sizes and, for optical properties, at three different wavelengths (405 nm, 488 nm and 532 nm). No significant difference, on thermal properties, was found in the range of nano-particles' sizes studied in this work; in opposition optical properties shown more sensitive to this parameter

Semiconductor-to-metallic flipping in a ZnFe{sub 2}O{sub 4}–graphene based smart nano-system: Temperature/microwave magneto-dielectric spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ameer, Shahid, E-mail: shahidameer@scme.nust.edu.pk [School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad (Pakistan); Gul, Iftikhar Hussain [School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad (Pakistan); Mahmood, Nasir [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Mujahid, Muhammad [School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad (Pakistan)

2015-01-15

Zn-(FeO{sub 2}){sub 2}–graphene smart nano-composites were synthesized using a novel modified solvothermal synthesis with different percentages of graphene. The structure of the nanocomposite was confirmed through X-ray diffraction, micro-Raman scattering spectroscopy, Ultraviolet–Visible spectroscopy, and Fourier transform infrared spectroscopy. The structural growth and morphological aspects were analyzed using scanning/transmission electron microscopy, revealing marvelous micro-structural features of the assembled nano-system resembling a maple leaf. To determine the composition, energy dispersive spectroscopy and X-ray photoelectron spectroscopy were used. Microwave magneto-dielectric spectroscopy revealed the improved dielectric properties of the nano-composite compared to those of the parent functional nanocrystals. Temperature gradient dielectric spectroscopy was used over the spectral range from 100 Hz to 5 MHz to reveal the phenomenological effect that the nanosystem flips from its usual semiconductor nature to a metallic nature with sensing temperature. Electrical conductivity and dielectric analysis indicated that the dielectric loss and the dielectric permittivity increased at room temperature. This extraordinary switching capability of the functionalized graphene nanosystem opens up a new dimension for engineering advanced and efficient smart composite materials. - Graphical abstract: Display Omitted - Highlights: • Zn-(FeO{sub 2}){sub 2}–graphene smart nano-composites were synthesized using a novel modified solvothermal synthesis. • The synthesized nano-system exhibits marvelous leaf like microstructure. • These nano-composites show improved magneto dielectric response. • This engineered smart nano-system shows phenomenological flipping from semiconductor like nature to metallic behavior.

Control of the Nano-Particle Weight Ratio in Stainless Steel Micro and Nano Powders by Radio Frequency Plasma Treatment

Directory of Open Access Journals (Sweden)

Dong-Yeol Yang

2015-11-01

Full Text Available This study describes how to make stainless steel hybrid micro-nano-powders (a mixture of micro-powder and nano-powder using an in situ one-step process via radio frequency (RF thermal plasma treatment. Nano-particles attached to micro-powders were successfully prepared by RF thermal plasma treatment of stainless steel powder with an average size of 35 μm. The ratio of nano-powders is estimated with a two-dimensional fluid simulation that calculates the temperature profile influencing the rate of surface evaporation. The simulation is conducted to determine the variation of the input power and the distance from the plasma torch to the feeding nozzle. It was demonstrated experimentally that the nano-powder ratio in the micro-nano-powder mixture can be controlled by adjusting the feeding rate, plasma power, feeding position and quenching effect during plasma treatment. The ratio of nano-particles in the micro-nano-powder mixture was controlled in a range from 0.1 (wt. % to 30.7 (wt. %.

Andromede project: Surface analysis and modification with probes from hydrogen to nano-particles in the MeV energy range

International Nuclear Information System (INIS)

Eller, Michael J.; Cottereau, Evelyne; Rasser, Bernard; Verzeroli, Elodie; Agnus, Benoit; Gaubert, Gabriel; Donzel, Xavier; Delobbe, Anne; Della-Negra, Serge

2015-01-01

The Andromede project is the center of a multi-disciplinary team which will build a new instrument for surface modification and analysis using the impact of probes from hydrogen to nano-particles (Au 400 +4 ) in the MeV range. For this new instrument a series of atomic, polyatomic, molecular and nano-particle ion beams will be delivered using two ion sources in tandem, a liquid metal ion source and an electron cyclotron resonance source. The delivered ion beams will be accelerated to high energy with a 4 MeV van de Graaff type accelerator. By using a suite of probes in the MeV energy range, ion beam analysis techniques, MeV atomic and cluster secondary ion mass spectrometry can all be performed in one location. A key feature of the instrument is its ability to produce an intense beam for injection into the accelerator. The commissioning of the two sources shows that intense beams from atomic ions to nano-particles can be delivered for subsequent acceleration. The calculations and measurements for the two sources are presented.

Nano-structured noble metal catalysts based on hexametallate architecture for the reforming of hydrocarbon fuels

Science.gov (United States)

Gardner, Todd H.

2015-09-15

Nano-structured noble metal catalysts based on hexametallate lattices, of a spinel block type, and which are resistant to carbon deposition and metal sulfide formation are provided. The catalysts are designed for the reforming of hydrocarbon fuels to synthesis gas. The hexametallate lattices are doped with noble metals (Au, Pt, Rh, Ru) which are atomically dispersed as isolated sites throughout the lattice and take the place of hexametallate metal ions such as Cr, Ga, In, and/or Nb. Mirror cations in the crystal lattice are selected from alkali metals, alkaline earth metals, and the lanthanide metals, so as to reduce the acidity of the catalyst crystal lattice and enhance the desorption of carbon deposit forming moieties such as aromatics. The catalysts can be used at temperatures as high as 1000.degree. C. and pressures up to 30 atmospheres. A method for producing these catalysts and applications of their use also is provided.

Size-controlled synthesis of transition metal nanoparticles through chemical and photo-chemical routes

Science.gov (United States)

Tangeysh, Behzad

The central objective of this work is developing convenient general procedures for controlling the formation and stabilization of nanoscale transition metal particles. Contemporary interest in developing alternative synthetic approaches for producing nanoparticles arises in large part from expanding applications of the nanomaterials in areas such as catalysis, electronics and medicine. This research focuses on advancing the existing nanoparticle synthetic routes by using a new class of polymer colloid materials as a chemical approach, and the laser irradiation of metal salt solution as a photo-chemical method to attain size and shape selectivity. Controlled synthesis of small metal nanoparticles with sizes ranging from 1 to 5nm is still a continuing challenge in nanomaterial synthesis. This research utilizes a new class of polymer colloid materials as nano-reactors and protective agents for controlling the formation of small transition metal nanoparticles. The polymer colloid particles were formed from cross-linking of dinegatively charged metal precursors with partially protonated poly dimethylaminoethylmethacrylate (PDMAEMA). Incorporation of [PtCl6]2- species into the colloidal particles prior to the chemical reduction was effectively employed as a new strategy for synthesis of unusually small platinum nanoparticles with narrow size distributions (1.12 +/-0.25nm). To explore the generality of this approach, in a series of proof-of-concept studies, this method was successfully employed for the synthesis of small palladium (1.4 +/-0.2nm) and copper nanoparticles (1.5 +/-0.6nm). The polymer colloid materials developed in this research are pH responsive, and are designed to self-assemble and/or disassemble by varying the levels of protonation of the polymer chains. This unique feature was used to tune the size of palladium nanoparticles in a small range from 1nm to 5nm. The procedure presented in this work is a new convenient room temperature route for synthesis of

Ion induced transformation of polymer films into diamond-like carbon incorporating silver nano particles

International Nuclear Information System (INIS)

Schwarz, Florian P.

2010-01-01

Silver containing diamond-like carbon (DLC) is an interesting material for medical engineering from several points of view. On the one hand DLC provides high mechanical robustness. It can be used as biocompatible and wear resistant coating for joint replacing implants. On the other hand silver has antimicrobial properties, which could reduce post-operative inflammations. However conventional production of Ag-DLC by co-deposition of silver and carbon in a plasma process is problematic since it does not allow for a separate control of nano particle morphology and matrix properties. In this work an alternative production method has been developed to circumvent this problem. In metall-DLC-production by ion implantation into a nano composite, silver nano particles are initially formed in solution and then incorporated within a polymer matrix. Finally the polymer is transformed into DLC by ion implantation. The aspects and single steps of this method were investigated with regard to the resulting material's properties. The goal was to design an economically relevant deposition method. Based on experimental results a model of the transformation process has been established, which has also been implemented in a computer simulation. Finally the antibacterial properties of the material have been checked in a biomedical test. Here a bacterial killing rate of 90% could be achieved. (orig.)

The Effect of Nano Loading and Ultrasonic Compounding of EVA/LDPE/Nano-magnesium Hydroxide on Mechanical Properties and Distribution of Nano Particles

Science.gov (United States)

Azman, I. A.; Salleh, R. M.; Alauddin, S. M.; Shueb, M. I.

2018-05-01

Blends of Ethylene Vinyl Acetate (EVA) and Low-Density Polyethylene (LDPE) are promising composite which have good mechanical properties to environmental stress cracking. However, they lack fire resistant properties, which limits it usage in wire and cable industry. In order to improve flame retardancy ability, a range of nano-magnesium hydroxide (nano-MH) loading which is from 0 phr to maximum of 20 phr with ultrasonic extrusion 0-100 kHz frequencies have been introduced. Ultrasonic extrusion was used to improve the distribution of nano-MH. It was found that, 10 phr of nano loading with 100 kHz ultrasonic assisted has greater tensile strength compared to the nanocomposite without ultrasonication. Further increase of nano MH loading, will decrease the tensile properties. Better elongation at break was observed at10 phr nano-MH with the frequency of 50 kHz. The sample of 20 phr of nanoMH assisted with 50 kHz ultrasonic exhibits good flexural properties while 10 phr of nano-MH without the ultrasonic assisted demonstrates good in izod impact properties. From the evaluation of mechanical properties studied, it was found that 10 phr of nano-MH has shown the best performance among all the samples tested for EVA/LDPE/nano-MH composites. Transmission Electron Microscopy (TEM) has been conducted on 10 phr sample with different frequencies in order to observe the distribution of nano-MH particles. The sample with 100 kHz frequency shows more uniform dispersion of nano-MH in EVA/LDPE composites. This investigation indicates that the ultrasonic technology can enhance the mechanical properties studied as well as the dispersion of nano particles in the composite.

FY 1999 report on the results of the development of technology of super metal. Development of nano/amorphous structure control materials; 1999 nendo super metal no gijutsu kaihatsu seika hokokusho. Nano amorphous kozo seigyo gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of reducing the amount of energy consumption of transportation equipment such as automobiles, the development is made of innovative metal materials enabling the weight reduction of members relatively on the basis of simple chemical components and by making more substantial improvement of characteristics such as strength and toughness than in the existing metals. For it, the following R and D are conducted in which nano crystal structure and non-equilibrium phase structure such as amorphous are controlled to the limits: 1) particle micro-dispersion technology; 2) high speed super plastic formation technology; 3) high density energy utilization control technology; 4) control cooling technology. In 1), study was made of alloy components and effects of the creation process which are needed for achievement of the nano level of crystal grain. In 2), conditions of vapor deposition and production in high speed particle deposition method are optimally selected, and amorphous and nano crystal structures can easily be produced. In 3), high corrosion-resistant amorphous alloy bulk materials with 5mm thickness and 10mm diameter were successfully trially manufactured. In 4), a bulk amorphous specimen with 10mm outer diameter, 6mm inner diameter and 1mm thickness which was fabricated in the forging method indicated favorable magnetic properties. A method to make a specimen which is more stable is being studied. (NEDO)

Femtosecond investigation of electronic and vibrational dynamics of metal nano-objects and local order in glasses

International Nuclear Information System (INIS)

Burgin, Julien

2007-01-01

In this Ph.D. work we have investigated the electronic and vibrational properties of metallic nano objects as a function of their size, shape and composition, and studied the vibrational modes in glasses, using femtosecond time-resolved spectroscopy. In mono-metallic copper clusters, acceleration of the electron-lattice energy exchanges for sizes smaller than 10 nm has been demonstrated, confirming previous results in gold and silver clusters. The small size regime, i.e., nanoparticles smaller than 2 nm, has been addressed. The results show the limit of the classical confined material approach. In bi-metallic clusters, electron-lattice interaction has been shown to reflect their composition for gold-silver materials, but exhibits a more complex behavior in the case of segregated nickel-silver particles. The impact of shape, structure and environment on the acoustic vibrations of metallic nano-objects has also been studied. Measurements performed in ensemble or pairs of prisms yielded evidence for local fluctuations of their coupling with the substrate. Nano-structuration effects have been demonstrated in nano-columns and segregated components. The vibrational modes associated to local order in glasses have been investigated using a high sensitivity impulsive stimulated Raman scattering technique. The 'defect modes' of normal and densified silica, associated to vibrations of ring structures, have been observed and characterized, yielding information on the evolution of the ring density. Performing similar measurements in germania, we have demonstrated the existence of a vibrational mode due to a similar ring structure and determined its characteristics [fr

3-dimensional free standing micro-structures by proton beam writing of Su 8-silver nanoParticle polymeric composite

Science.gov (United States)

Igbenehi, H.; Jiguet, S.

2012-09-01

Proton beam lithography a maskless direct-write lithographic technique (well suited for producing 3-Dimensional microstructures in a range of resist and semiconductor materials) is demonstrated as an effective tool in the creation of electrically conductive freestanding micro-structures in an Su 8 + Nano Silver polymer composite. The structures produced show non-ohmic conductivity and fit the percolation theory conduction model of tunneling of separated nanoparticles. Measurements show threshold switching and a change in conductivity of at least 4 orders of magnitude. The predictable range of protons in materials at a given energy is exploited in the creation of high aspect ratio, free standing micro-structures, made from a commercially available SU8 Silver nano-composite (GMC3060 form Gersteltec Inc. a negative tone photo-epoxy with added metallic nano-particles(Silver)) to create films with enhanced electrical properties when exposed and cured. Nano-composite films are directly written on with a finely focused MeV accelerated Proton particle beam. The energy loss of the incident proton beams in the target polymer nano- composite film is concentrated at the end of its range, where damage occurs; changing the chemistry of the nano-composite film via an acid initiated polymerization - creating conduction paths. Changing the energy of the incident beams provide exposed regions with different penetration and damage depth - exploited in the demonstrated cantilever microstructure.

Agglomerated polymer monoliths with bimetallic nano-particles as flow-through micro-reactors

International Nuclear Information System (INIS)

Floris, P.; Twamley, B.; Nesterenko, P.N.; Paull, B.; Connolly, D.

2012-01-01

Polymer monoliths in capillary format have been prepared as solid supports for the immobilisation of platinum/palladium bimetallic nano-flowers. Optimum surface coverage of nano-flowers was realised by photografting the monoliths with vinyl azlactone followed by amination with ethylenediamine prior to nano-particle immobilisation. Field emission SEM imaging was used as a characterisation tool for evaluating nano-particle coverage, together with BET surface area analysis to probe the effect of nano-particle immobilisation upon monolith morphology. Ion exchange chromatography was also used to confirm the nature of the covalent attachment of nano-flowers on the monolithic surface. In addition, EDX and ICP analyses were used to quantify platinum and palladium on modified polymer monoliths. Finally the catalytic properties of immobilised bimetallic Pd/Pt nano-flowers were evaluated in flow-through mode, exploiting the porous interconnected flow-paths present in the prepared monoliths (pore diameter ∼ 1-2 μm). Specifically, the reduction of Fe (III) to Fe (II) and the oxidation of NADH to NAD+ were selected as model redox reactions. The use of a porous polymer monolith as an immobilisation substrate (rather than aminated micro-spheres) eliminated the need for a centrifugation step after the reaction. (author)

Comparison on exfoliated graphene nano-sheets and triturated graphite nano-particles for mode-locking the Erbium-doped fibre lasers

Science.gov (United States)

Yang, Chun-Yu; Lin, Yung-Hsiang; Wu, Chung-Lun; Cheng, Chih-Hsien; Tsai, Din-Ping; Lin, Gong-Ru

2018-06-01

Comparisons on exfoliated graphene nano-sheets and triturated graphite nano-particles for mode-locking the Erbium-doped fiber lasers (EDFLs) are performed. As opposed to the graphite nano-particles obtained by physically triturating the graphite foil, the tri-layer graphene nano-sheets is obtained by electrochemically exfoliating the graphite foil. To precisely control the size dispersion and the layer number of the exfoliated graphene nano-sheet, both the bias of electrochemical exfoliation and the speed of centrifugation are optimized. Under a threshold exfoliation bias of 3 volts and a centrifugation at 1000 rpm, graphene nano-sheets with an average diameter of 100  ±  40 nm can be obtained. The graphene nano-sheets with an area density of 15 #/µm2 are directly imprinted onto the end-face of a single-mode fiber made patchcord connector inside the EDFL cavity. Such electrochemically exfoliated graphene nano-sheets show comparable saturable absorption with standard single-graphene and perform the self-amplitude modulation better than physically triturated graphite nano-particles. The linear transmittance and modulation depth of the inserted graphene nano-sheets are 92.5% and 53%, respectively. Under the operation with a power gain of 21.5 dB, the EDFL can be passively mode-locked to deliver a pulsewidth of 454.5 fs with a spectral linewidth of 5.6 nm. The time-bandwidth product of 0.31 is close to the transform limit. The Kelly sideband frequency spacing of 1.34 THz is used to calculate the chirp coefficient as  ‑0.0015.

Airflow structures and nano-particle deposition in a human upper airway model

Science.gov (United States)

Zhang, Z.; Kleinstreuer, C.

2004-07-01

Considering a human upper airway model, or equivalently complex internal flow conduits, the transport and deposition of nano-particles in the 1-150 nm diameter range are simulated and analyzed for cyclic and steady flow conditions. Specifically, using a commercial finite-volume software with user-supplied programs as a solver, the Euler-Euler approach for the fluid-particle dynamics is employed with a low-Reynolds-number k- ω model for laminar-to-turbulent airflow and the mass transfer equation for dispersion of nano-particles or vapors. Presently, the upper respiratory system consists of two connected segments of a simplified human cast replica, i.e., the oral airways from the mouth to the trachea (Generation G0) and an upper tracheobronchial tree model of G0-G3. Experimentally validated computational fluid-particle dynamics results show the following: (i) transient effects in the oral airways appear most prominently during the decelerating phase of the inspiratory cycle; (ii) selecting matching flow rates, total deposition fractions of nano-size particles for cyclic inspiratory flow are not significantly different from those for steady flow; (iii) turbulent fluctuations which occur after the throat can persist downstream to at least Generation G3 at medium and high inspiratory flow rates (i.e., Qin⩾30 l/min) due to the enhancement of flow instabilities just upstream of the flow dividers; however, the effects of turbulent fluctuations on nano-particle deposition are quite minor in the human upper airways; (iv) deposition of nano-particles occurs to a relatively greater extent around the carinal ridges when compared to the straight tubular segments in the bronchial airways; (v) deposition distributions of nano-particles vary with airway segment, particle size, and inhalation flow rate, where the local deposition is more uniformly distributed for large-size particles (say, dp=100 nm) than for small-size particles (say, dp=1 nm); (vi) dilute 1 nm particle

The synthesis and characterization of water-reducible nanoscale Colloidal Unimolecular Polymer (CUP) particles

Science.gov (United States)

Riddles, Cynthia Jeannette

The coatings industry has adapted to more stringent guidelines in paint formulations. Current VOC (volatile organic compound) limits placed by the federal government have pushed the industry toward the development of paint formulations which have very little to no VOC's. The development of Colloidal Unimolecular Polymer (CUP) particles is a step in the direction of providing a resin system which exists in zero VOC aqueous dispersion. The CUP particles are a part of the polymer field of Single Chain Nano Particles (SCNP) and ranged in diameters of 3-9 nm. The research presented in this dissertation describes the synthesis and design of these particles along with the various means of instrumentation used to gain insight into the structure and nature of these particles when suspended in aqueous medium.

Ultraviolet spectra of CeO2 nano-particles

International Nuclear Information System (INIS)

Tsunekawa, S.; Sivamohan, R.; Ohsuna, T.; Kasuya, A.; Takahashi, H.; Tohji, K.

1998-01-01

Full text: Quantum size effect is generally expected in nanometer size materials. The effect has been observed in many metal clusters and semiconducting nano-particles, but seldom in oxides, because the size control of crystalline oxides is generally difficult due to the ionic bond character. CeO 2 (ceria) is one of the rare-earth oxides and the size effect is worth studying from the viewpoint of an ultraviolet (u.v.) spectroscopy and applications. This report describes the first observation of a blue shift of u.v. spectra in ceria nano-particles of 2-5 nm in diameter with its deviation within 20%. A ceria aqueous sol (pH ≅ 2.5) having particle sizes under 6 nm in diameter was produced by ultrafiltration with a polyether sulfone membrane (SIP-1013, Asahi Chemical Industry Co.) from an original ceria aqueous sol (pH ≅ 1.5) having particle sizes extending over a wide range. Obtained sol contains a high concentration of Ce 3+ ions because of the high acidity. In order to separate ceria particles from Ce 3+ ions and fractionate the particle size, two kinds of anion-type surfactants were used in microemulsification process with toluene and water. One is sodium dodecylbenzene sulfonate (SD-BS) which is 2 nm in length and another is sodium octyl sulfonate (SOS) which is 1.2 nm in length. U.v. spectroscopic measurements and high resolution transmission electron microscopic (HRTEM) observations were performed for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t , where (SOS) t is a ceria suspension in toluene obtained by an emulsification with SOS surfactant, (SOS+SOS) t indicates the same product obtained by the further emulsification with SOS for an aqueous phase of the emulsion with SOS, and (SDBS+SOS+SDBS) t means that obtained by an additional emulsification with SDBS for an aqueous phase obtained by two successive emulsifications with SDBS and SOS. Optical density data for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t show absorption edges at 4076 Angstroms, 3997

CHF Enhancement in Flow Boiling using Al2O3 Nano-Fluid and Al2O3 Nano-Particle Deposited Tube

International Nuclear Information System (INIS)

Kim, Tae Il; Chun, T. H.; Chang, S. H.

2010-01-01

Nano-fluids are considered to have strong ability to enhance CHF. Most CHF experiments using nano-fluids were conducted in pool boiling conditions. However there are very few CHF experiments with nano-fluids in flow boiling condition. In the present study, flow boiling CHF experiments using bare round tube with Al 2 O 3 nano-fluid and Al 2 O 3 nano-particle deposited tube with DI water were conducted under atmospheric pressure. CHFs were enhanced up to ∼ 80% with Al 2 O 3 nano-fluid and CHFs with Al 2 O 3 nano-particle deposited tube were also enhanced up to ∼ 80%. Inner surface of test section tube were observed by SEM and AFM after CHF experiments

Transparent electrode designs based on optimal nano-patterning of metallic films

KAUST Repository

Catrysse, Peter B.

2010-09-10

Transparent conductive electrodes are critical to the operation of optoelectronic devices, such as photovoltaic cells and light emitting diodes. Effective electrodes need to combine excellent electrical and optical properties. Metal oxides, such as indium tin oxide, are commonly used. There is substantial interest in replacing them, however, motivated by practical problems and recent discoveries regarding the optics of nano-patterned metals. When designing nano-patterned metallic films for use as electrodes, one needs to account for both optical and electrical properties. In general, it is insufficient to optimize nano-structured films based upon optical properties alone, since structural variations will also affect the electrical properties. In this work, we investigate the need for simultaneous optical and electrical performance by analyzing the optical properties of a class of nano-patterned metallic electrodes that is obtained by a constant-sheet-resistance transformation. Within such a class the electrical and optical properties can be separated, i.e., the sheet resistance can be kept constant and the transmittance can be optimized independently. For simple one-dimensional periodic patterns with constant sheet-resistance, we find a transmission maximum (polarization-averaged) when the metal sections are narrow (< 40 nm, ~ 10% metal fill-factor) and tall (> 100 nm). Our design carries over to more complex two-dimensional (2D) patterns. This is significant as there are no previous reports regarding numerical studies on the optical and electrical properties of 2D nano-patterns in the context of electrode design.

Comparison of flux motion in type-II superconductors including pinning centers with the shapes of nano-rods and nano-particles by using 3D-TDGL simulation

International Nuclear Information System (INIS)

Ito, Shintaro; Ichino, Yusuke; Yoshida, Yutaka

2015-01-01

Highlights: • We constructed the 3D-TDGL simulator to calculate the flux motion. • We assumed two superconductors including only nano-rods and only nano-particles. • We succeeded to simulate the flux motion for various magnetic field angles. • If anyone introduce nano-rod, controlling the “single-kink” motion is very important. • The introduction of nano-particles is effective to pin the “single-kink” motion. - Abstract: Time-dependent Ginzburg–Landau (TDGL) equations are very useful method for simulation of the motion of flux quanta in type-II superconductors. We constructed the 3D-TDGL simulator and succeeded to simulate the motion of flux quanta in 3-dimension. We carried out the 3D-TDGL simulation to compare two superconductors which included only pinning centers with the shape of nano-rods and only nano-particle-like pinning centers in the viewpoint of the flux motion. As a result, a motion of “single-kink” caused the whole motion of a flux quantum in the superconductor including only the nano-rods. On the other hand, in the superconductor including the nano-particles, the flux quanta were pinned by the nano-particles in the various magnetic field applied angles. As the result, no “single-kink” occurred in the superconductor including the nano-particles. Therefore, the nano-particle-like pinning centers are effective shape to trap flux quanta for various magnetic field applied angles.

Direct Write Processing of Multi-micron Thickness Copper Nano-particle Paste on Flexible Substrates with 532 nm Laser Wavelength

Science.gov (United States)

Lopez-Espiricueta, Dunia; Fearon, Eamonn; Edwardson, Stuart; Dearden, Geoffrey

The Laser Assisted Direct Write (LA-DW) method has been implemented in the development of different markets and material processing, recently also used for creating Printed Circuit Boards (PCB) or electrical circuitry. The process consists in the deposition of metallic nano-particle (NP) inks, which are afterwards cured or sintered by laser irradiation, thus creating conductive pathways; advantages are speed, accuracy and the protection of the heat affected zone (HAZ). This research will study the behaviour of the heat dissipation relatively within the Nano-particle Copper paste after being irradiated with 1064 nm and 532 nm wavelengths, research will be developed on different widths and depths deposited onto flat surfaces such as flexible PET. Comparisons to be made between resistivity results obtained from different wavelengths.

Application of the laser pyrolysis to the synthesis of SiC, TiC and ZrC pre-ceramics nano-powders

International Nuclear Information System (INIS)

Leconte, Y.; Maskrot, H.; Combemale, L.; Herlin-Boime, N.; Reynaud, C.

2007-01-01

Refractory carbide nano-structured ceramics appear to be promising materials for high temperature applications requiring hard materials such as nuclear energy industry. Such carbide materials are usually obtained with micrometric sizes from the high temperature carbo-reduction of an oxide phase in a raw mixture of C black and titania or zirconia. TiC and ZrC nano-powders were produced from an intimate mixture of oxide nano-grains with free C synthesized by laser pyrolysis from the decomposition of a liquid precursor. The temperature and the duration of the thermal treatment leading to the carburization were decreased, allowing the preservation of the nano-scaled size of the starting grains. A solution of titanium iso-prop-oxide was laser-pyrolyzed with ethylene as sensitizer in order to synthesize Ti/C/O powders. These powders were composed of crystalline TiO 2 nano-grains mixed with C. Annealing under argon enabled the formation of TiC through the carburization of TiO 2 by free C. The final TiC mean grain size was about 80 nm. Zr/O/C powders were prepared from a solution of zirconium butoxide and were composed of ZrO 2 crystalline nano-grains and free C. The same thermal treatment as for TiC, but at higher temperature, showed the formation of crystalline ZrC with a final mean grain size of about 40 nm. These two liquid routes of nano-particles synthesis are also compared to the very efficient gaseous route of SiC nano-powders synthesis from a mixture of silane and acetylene. (authors)

Antibacterial performance of nano polypropylene filter media containing nano-TiO{sub 2} and clay particles

Energy Technology Data Exchange (ETDEWEB)

Shafiee, Sara; Zarrebini, Mohammad; Naghashzargar, Elham, E-mail: e.naghashzargar@tx.iut.ac.ir; Semnani, Dariush, E-mail: d-semnani@cc.iut.ac.ir [Isfahan University of Technology, Department of Textile Engineering (Iran, Islamic Republic of)

2015-10-15

Disinfection and elimination of pathogenic microorganisms from liquid can be achieved by filtration process using antibacterial filter media. The advent of nanotechnology has facilitated the introduction of membranes consisting of nano-fiber in filtration operations. The melt electro-spun fibers due to their extremely small diameters are used in the production of this particular filtration medium. In this work, antibacterial polypropylene filter medium containing clay particles and nano-TiO{sub 2} were made using melt electro-spun technology. Antibacterial performance of polypropylene nano-filters was evaluated using E. coli bacteria. Additionally, filtration efficiency of the samples in terms fiber diameter, filter porosity, and fiber distribution using image processing technique was determined. Air permeability and dust aerosol tests were conducted to establish the suitability of the samples as a filter medium. It was concluded that as far as antibacterial property is concerned, nano-fibers filter media containing clay particles are preferential to similar media containing TiO{sub 2} nanoparticles.

PLA micro- and nano-particles.

Science.gov (United States)

Lee, Byung Kook; Yun, Yeonhee; Park, Kinam

2016-12-15

Poly(d,l-lactic acid) (PLA) has been widely used for various biomedical applications for its biodegradable, biocompatible, and nontoxic properties. Various methods, such as emulsion, salting out, and precipitation, have been used to make better PLA micro- and nano-particle formulations. They are widely used as controlled drug delivery systems of therapeutic molecules, including proteins, genes, vaccines, and anticancer drugs. Even though PLA-based particles have challenges to overcome, such as low drug loading capacity, low encapsulation efficiency, and terminal sterilization, continuous innovations in particulate formulations will lead to development of clinically useful formulations. Copyright © 2016 Elsevier B.V. All rights reserved.

Tunable potential well for plasmonic trapping of metallic particles by bowtie nano-apertures.

Science.gov (United States)

Lu, Yu; Du, Guangqing; Chen, Feng; Yang, Qing; Bian, Hao; Yong, Jiale; Hou, Xun

2016-09-26

In this paper, the tunable optical trapping dependence on wavelength of incident beam is theoretically investigated based on numerical simulations. The Monte Carlo method is taken into account for exploring the trapping characteristics such as average deviation and number distribution histogram of nanoparticles. It is revealed that both the width and the depth of potential well for trapping particles can be flexibly adjusted by tuning the wavelength of the incident beam. In addition, incident wavelengths for the deepest potential well and for the strongest stiffness at bottom are separated. These phenomena are explained as the strong plasmon coupling between tweezers and metallic nanoparticles. In addition, required trapping fluence and particles' distributions show distinctive properties through carefully modifying the incident wavelengths from 1280 nm to 1300 nm. Trapping with lowest laser fluence can be realized with 1280 nm laser and trapping with highest precision can be realized with 1300 nm laser. This work will provide theoretical support for advancing the manipulation of metallic particles and related applications such as single-molecule fluorescence and surface enhanced Raman spectroscopy.

Fundamental Issues of Nano-fluid Behavior

International Nuclear Information System (INIS)

Williams, Wesley C.

2006-01-01

This paper will elucidate some of the behaviors of nano-fluids other than the abnormal conductivity enhancement, which are of importance to the experimental and engineering use of nano-fluids. Nano-fluid is the common name of any sol colloid involving nano-scale (less than 100 nm) sized particles dispersed within a base fluid. It has been shown previously that the dispersion of nano-particulate metallic oxides into water can increase thermal conductivity up to 30-40% over that of the base fluid and anomalously more than the mere weighed average of the colloid. There is a great potential for the use of nano-fluids as a way to enhance fluid/thermal energy transfer systems. Due to the recentness of nano-fluid science, there are still many issues which have not been fully investigated. This paper should act as a primer for the basic understanding of nano-fluid behavior. Particle size and colloid stability are of key importance to the functionality of nano-fluids. The pH and concentration/loading of nano-fluids can alter the size of the nano-particles and also the stability of the fluids. It will be shown through experiment and colloid theory the importance of these parameters. Furthermore, most of the existing literature uses volume percentage as the measure of particle loading, which can often be misleading. There will be discussion of this and other misleading ideas in nano-fluid science. (author)

NanoXCT: a novel technique to probe the internal architecture of pharmaceutical particles.

Science.gov (United States)

Wong, Jennifer; D'Sa, Dexter; Foley, Matthew; Chan, John Gar Yan; Chan, Hak-Kim

2014-11-01

To demonstrate the novel application of nano X-ray computed tomography (NanoXCT) for visualizing and quantifying the internal structures of pharmaceutical particles. An Xradia NanoXCT-100, which produces ultra high-resolution and non-destructive imaging that can be reconstructed in three-dimensions (3D), was used to characterize several pharmaceutical particles. Depending on the particle size of the sample, NanoXCT was operated in Zernike Phase Contrast (ZPC) mode using either: 1) large field of view (LFOV), which has a two-dimensional (2D) spatial resolution of 172 nm; or 2) high resolution (HRES) that has a resolution of 43.7 nm. Various pharmaceutical particles with different physicochemical properties were investigated, including raw (2-hydroxypropyl)-beta-cyclodextrin (HβCD), poly (lactic-co-glycolic) acid (PLGA) microparticles, and spray-dried particles that included smooth and nanomatrix bovine serum albumin (BSA), lipid-based carriers, and mannitol. Both raw HβCD and PLGA microparticles had a network of voids, whereas spray-dried smooth BSA and mannitol generally had a single void. Lipid-based carriers and nanomatrix BSA particles resulted in low quality images due to high noise-to-signal ratio. The quantitative capabilities of NanoXCT were also demonstrated where spray-dried mannitol was found to have an average void volume of 0.117 ± 0.247 μm(3) and average void-to-material percentage of 3.5%. The single PLGA particle had values of 1993 μm(3) and 59.3%, respectively. This study reports the first series of non-destructive 3D visualizations of inhalable pharmaceutical particles. Overall, NanoXCT presents a powerful tool to dissect and observe the interior of pharmaceutical particles, including those of a respirable size.

Dwell-time effect on the synthesis of a nano-structured material in water by using Ni wire explosion

International Nuclear Information System (INIS)

Eom, Gyu Sub; Kwon, Hyeok Jung; Cho, Yong Sub; Paek, Kwang Hyun; Joo, Won Tae

2014-01-01

Nickel nano-structured materials are synthesized by using a wire explosion in water. Based on an analysis of each step of the wire explosion, we propose insufficient energy deposition before a plasma restrike as the cause for the inclusion of coarse particles in the wire-explosion product. We confirmed that more energy, in excess of 30%, could be deposited by increasing the dwell time, which resulted from a compression of vapor by the surrounding water and from suppression of plasma restrikes. Because of an increased energy loss into the surrounding water, the specific energy increased by two-fold compared to a gas atmosphere. The synthesized nano-structured nickel showed a uniform particle size of 20 nm with a few coarse particles that were mainly metallic nickel with a little oxide and hydroxide phases. The possibility for large-volume production through a continuous explosion of 300 shots was confirmed.

Nano- and microsized cubic gel particles from cyclodextrin metal-organic frameworks.

Science.gov (United States)

Furukawa, Yuki; Ishiwata, Takumi; Sugikawa, Kouta; Kokado, Kenta; Sada, Kazuki

2012-10-15

Sweet cube o' mine: Bottom-up control of gel particles has been regarded as a great challenge. By employing internal cross-linking of cyclodextrin metal-organic frameworks, cubic sugar gels were formed with sharp edges that reflect the shape of the crystals. This enabled the fabrication of shape- and size-controlled polymer gels from porous crystals (see picture). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method and electrochemical cell for synthesis and treatment of metal monolayer electrocatalysts metal, carbon, and oxide nanoparticles ion batch, or in continuous fashion

Science.gov (United States)

Adzic, Radoslav; Zhang, Junliang; Sasaki, Kotaro

2015-04-28

An apparatus and method for synthesis and treatment of electrocatalyst particles in batch or continuous fashion is provided. In one embodiment, the apparatus comprises a sonication bath and a two-compartment chamber submerged in the sonication bath. The upper and lower compartments are separated by a microporous material surface. The upper compartment comprises a cover and a working electrode (WE) connected to a Pt foil contact, with the foil contact connected to the microporous material. The upper chamber further comprises reference counter electrodes. The lower compartment comprises an electrochemical cell containing a solution of metal ions. In one embodiment, the method for synthesis of electrocatalysts comprises introducing a plurality of particles into the apparatus and applying sonication and an electrical potential to the microporous material connected to the WE. After the non-noble metal ions are deposited onto the particles, the non-noble metal ions are displaced by noble-metal ions by galvanic displacement.

Passion fruit-like nano-architectures: a general synthesis route

Science.gov (United States)

Cassano, D.; David, J.; Luin, S.; Voliani, V.

2017-03-01

Noble metal nanostructures have demonstrated a number of intriguing features for both medicine and catalysis. However, accumulation issues have prevented their clinical translation, while their use in catalysis has shown serious efficiency and stability hurdles. Here we introduce a simple and robust synthetic protocol for passion fruit-like nano-architectures composed by a silica shell embedding polymeric arrays of ultrasmall noble metal nanoparticles. These nano-architectures show interesting features for both oncology and catalysis. They avoid the issue of persistence in organism thanks to their fast biodegradation in renal clearable building blocks. Furthermore, their calcination results in yolk-shell structures composed by naked metal or alloy nanospheres shielded from aggregation by a silica shell.

A ferrite nano-particles based fully printed process for tunable microwave components

KAUST Repository

Ghaffar, Farhan A.

2016-08-15

With the advent of nano-particles based metallic inks, inkjet printing emerged as an attractive medium for fast prototyping as well as for low cost and flexible electronics. However, at present, it is limited to printing of metallic inks on conventional microwave substrates. For fully printed designs, ideally, the substrate must also be printed. In this work, we demonstrate a fully printed process utilizing a custom Fe2O3 based magnetic ink for functional substrate printing and a custom silver-organo-complex (SOC) ink for metal traces printing. Due to the magnetic nature of the ink, this process is highly suitable for tunable microwave components. The printed magnetic substrate is characterized for the magnetostatic as well as microwave properties. The measured B(H) curve shows a saturation magnetization and remanence of 1560 and 350 Gauss respectively. As a proof of concept, a patch antenna is implemented in the proposed stack up which shows a tuning range of 4 % around the center frequency. © 2016 IEEE.

Synthesis of uniform nano-structured lead oxide by sonochemical method and its application as cathode and anode of lead-acid batteries

International Nuclear Information System (INIS)

Karami, Hassan; Karimi, Mohammad Ali; Haghdar, Saeed

2008-01-01

This paper discusses the results of a research aimed at investigating the synthesis of nano-structured lead oxide through reaction of lead nitrate solution and sodium carbonate solution by the sonochemical method. At the first, lead carbonate was obtained in a synthesized solution and then, after filtration, it was calcinated at the temperature of 320 deg. C so that nano-structured lead oxide can be produced. The effects of different parameters on particle size and morphology of final lead oxide powder were optimized by a 'one at a time' method. The prepared lead oxide powder was characterized by scanning electron microscopy (SEM), transmission electron spectroscopy (TEM) and X-ray diffraction (XRD). Under optimum conditions, uniformed and homogeneous nano-structured lead oxide powder with more spongy morphology and particle size of 20-40 nm was obtained. The synthesized lead oxide, as anode and cathode of lead-acid batteries, showed an excellent discharge capacity (140 mA h/g)

Graphene–Noble Metal Nano-Composites and Applications for Hydrogen Sensors

Directory of Open Access Journals (Sweden)

Sukumar Basu

2017-10-01

Full Text Available Graphene based nano-composites are relatively new materials with excellent mechanical, electrical, electronic and chemical properties for applications in the fields of electrical and electronic devices, mechanical appliances and chemical gadgets. For all these applications, the structural features associated with chemical bonding that involve other components at the interface need in-depth investigation. Metals, polymers, inorganic fibers and other components improve the properties of graphene when they form a kind of composite structure in the nano-dimensions. Intensive investigations have been carried out globally in this area of research and development. In this article, some salient features of graphene–noble metal interactions and composite formation which improve hydrogen gas sensing properties—like higher and fast response, quick recovery, cross sensitivity, repeatability and long term stability of the sensor devices—are presented. Mostly noble metals are effective for enhancing the sensing performance of the graphene–metal hybrid sensors, due to their superior catalytic activities. The experimental evidence for atomic bonding between metal nano-structures and graphene has been reported in the literature and it is theoretically verified by density functional theory (DFT. Multilayer graphene influences gas sensing performance via intercalation of metal and non-metal atoms through atomic bonding.

Behaviour of TEM metal grids during in-situ heating experiments.

Science.gov (United States)

Zhang, Zaoli; Su, Dangsheng

2009-05-01

The stability of Ni, Cu, Mo and Au transmission electron microscope (TEM) grids coated with ultra-thin amorphous carbon (alpha-C) or silicon monoxide film is examined by in-situ heating up to a temperature in the range 500-850 degrees C in a transmission electron microscope. It is demonstrated that some grids can generate nano-particles either due to the surface diffusion of metal atoms on amorphous film or due to the metal evaporation/redeposition. The emergence of nano-particles can complicate experimental observations, particularly in in-situ heating studies of dynamic behaviours of nano-materials in TEM. The most widely used Cu grid covered with amorphous carbon is unstable, and numerous Cu nano-particles start to form once the heating temperature reaches 600 degrees C. In the case of Ni grid covered with alpha-C film, a large number of Ni nano-crystals occur immediately when the temperature approaches 600 degrees C, accompanied by the graphitization of amorphous carbon. In contrast, both Mo and Au grids covered with alpha-C film exhibit good stability at elevated temperature, for instance, up to 680 and 850 degrees C for Mo and Au, respectively, and any other metal nano-particles are detected. Cu grid covered Si monoxide thin film is stable up to 550 degrees C, but Si nano-crystals appear under intensive electron beam. The generated nano-particles are well characterized by spectroscopic techniques (EDXS/EELS) and high-resolution TEM. The mechanism of nano-particle formation is addressed based on the interactions between the metal grid and the amorphous carbon film and on the sublimation of metal.

Synthesis of MnO nano-particle@Flourine doped carbon and its application in hybrid supercapacitor

Energy Technology Data Exchange (ETDEWEB)

Qu, Deyu; Feng, Xiaoke [Department of Chemistry, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, Hubei (China); Wei, Xi [School of Materials Science and Engineering, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei (China); Guo, Liping [Department of Chemistry, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, Hubei (China); Cai, Haopeng, E-mail: cai_haopeng@whut.edu.cn [School of Materials Science and Engineering, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei (China); Tang, Haolin [School of Materials Science and Engineering, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei (China); Xie, Zhizhong, E-mail: zhizhong_xie@163.com [Department of Chemistry, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, Hubei (China)

2017-08-15

Highlights: • A Fluorine doped carbon encapsulated MnO nanoparticle material was fabricated through a self-assembly method. • Nafion ionomers was used as the fluorine and carbon precursor. • A lithium ion supercapacitor was assemblied by using MnO@FC and porous carbon. • A stable energy density as well as superior cycling stability were demonstrated in this hybrid system. - Abstract: A flourine doped carbon materials encapsulated MnO nano-particle was synthesized through a self-assembly method. The MnO nano-crystal covered with a thin layer of graphite were achieved. This hybrid MnO/carbon materials were employed as negative electrode in a new lithium ion hybrid supercapacitor, while the electrochemical double-layer porous carbon served as positive electrode. The electrochemical performances of this hybrid device were investigated and exhibited relative high capacity upto 40 mAh g{sup −1} in an applied current of 200 mAh g{sup −1}, good rate performance as well as superior cycling stability.

Synthesis of nano-Au doped SiO2 aerogels by seeding method

International Nuclear Information System (INIS)

Ren Hongbo; Wan Xiaobo; Zhang Lin; Du Aiming; Xiu Peng

2006-01-01

A new approach to synthesize gold nano cluster doped aerogel on the basis of surface-catalyzed reduction of metal ions was described. Au nano particles were formed in a silica aerogel matrix by hydroxylamine seeding method of reducing gold ions on the silica colloidal surface. Subsequently, the pH value of system was adjusted to about 7-8, the gel formed within 2 h. After aging for 2 d, the gels were washed in aceton, and then dried supercritically (from CO 2 ) to yield aerogels. The reduction process was attributed to hydroxylamine-induced surface catalysis. Au clusters in the aerogel monoliths were characterized with optical adsorption, transmission electron microscopy. These techniques have shown the cluster size and weight content in the aerogels. Brunauer-emmett-teller surface area measurements show that the specific surface area of silica aerogels and doped aerogels are higher than 800 m 2 /g. (authors)

Growth of VO2 Nano wires from Supercooled Liquid Nano droplets and E-beam Irradiation for Ultra-sensitive sensor

International Nuclear Information System (INIS)

Byun, Ji Won; Baik, Jeong Min; Lee, Sang Hyun; Lee, Byung Cheol

2011-01-01

Vanadium dioxide is an interesting material on account of its easily accessible and sharp Mott metal-insulator transition at ∼ 68 .deg. C in the bulk, which is of great interest in sensing and catalytic applications. In this Paper, we describe the synthesis and properties of VO 2 nano wires as novel catalytic and gas sensor materials based on electron beam irradiation. High yields of single crystalline VO 2 nano wires are synthesized by atmospheric-pressure, physical vapor deposition using V 2 O 5 layer. Pd-decorated VO 2 nano wire sensors show extraordinary sensitivity towards hydrogen, an almost 3 order-of-magnitude increase in the current through the nano wire. By the Eb irradiation, the conductance of the nano wires significantly increased up to 5 times, reducing the response time by half and the operating temperature. The metal nanoparticles-VO 2 nano wire system will be very promising for high-sensitivity and high-selectivity under low temperature less than 100. deg. C

A fully printed ferrite nano-particle ink based tunable antenna

KAUST Repository

Ghaffar, Farhan A.

2016-11-02

Inkjet printing or printing in general has emerged as a very attractive method for the fabrication of low cost and large size electronic systems. However, most of the printed designs rely on nano-particle based metallic inks which are printed on conventional microwave substrates. In order to have a fully printed fabrication process, the substrate also need to be printed. In this paper, a fully printed multi-layer process utilizing custom Fe2O3 based magnetic ink and a silver organic complex (SOC) ink is demonstrated for tunable antennas applications. The ink has been characterized for high frequency and magnetostatic properties. Finally as a proof of concept, a microstrip patch antenna is realized using the proposed fabrication technique which shows a tuning range of 12.5 %.

Synthesis, structural, dielectric and magnetic properties of polyol assisted copper ferrite nano particles

Energy Technology Data Exchange (ETDEWEB)

Pavithradevi, S. [Assistant Professor, Department of Physics, Park College of Engineering and Technology, Coimbatore (India); Suriyanarayanan, N., E-mail: madurasuri2210@yahoo.com [Prof & Head, Department of Physics, Government College of Technology, Coimbatore (India); Boobalan, T. [Lecturer, Department of Physics, PSG Polytechnic College, Coimbatore (India)

2017-03-15

Nanocrystalline copper ferrite CuFe{sub 2}O{sub 4} is synthesized by co-precipitation method in ethylene glycol as chelating agent, using sodium Hydroxide as precipitator at pH 8. The as synthesized CuFe{sub 2}O{sub 4} is annealed at temperatures of 350 °C, 700 °C, and 1050 °C for 2 h respectively. The thermal analysis of the synthesized sample is done by TG technique. It is shown that at 260 °C ethylene glycol has evaporated completely and after 715 °C, spinel ferrite is formed with a cubic structure. The calculated lattice parameters are in agreement with the reported values. FTIR spectra of CuFe{sub 2}O{sub 4} nano particles are as synthesized and annealed at 1050 °C and recorded between 400 cm{sup −1} and 4000 cm{sup −1}. It shows that when the temperature increases ethylene glycol gradually evaporates. Finally, nano crystalline single phase spinel ferrite is obtained. X-ray diffraction (XRD) and electron diffraction (EDS) studies show that the sample is indexed as the face centered cubic spinel structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the particles are flaky and spherical with the crystallite size in the range of 25–34 nm. From the dielectric studies, the dielectric constant decreases as the frequency increases. Low value of dielectric loss at higher frequencies suggests that the material is suitable for high frequency applications. AC conductivity increases with frequency. The magnetic properties of the samples are measured using a vibrating sample magnetometer (VSM) at room temperature, which shows that the sample exhibited a typical super paramagnetic behavior at low temperature. The saturation magnetization, remanant magnetism, and coercivity increases with applied field. - Highlights: • Complete removal of hematite phase along with ethylene glycol at 1050 °C. • Large decrease in particle sizes noticed along with ethylene glycol. • Ethylene glycol improves purity of the

Removal of heavy metals using bentonite supported nano-zero valent iron particles

Science.gov (United States)

Zarime, Nur Aishah; Yaacob, Wan Zuhari Wan; Jamil, Habibah

2018-04-01

This study reports the composite nanoscale zero-valent iron (nZVI) which was successfully synthesized using low cost natural clay (bentonite). Bentonite composite nZVI (B-nZVI) was introduced to reduce the agglomeration of nZVI particles, thus will used for heavy metals treatment. The synthesized material was analyzed using physical, mineralogy and morphology analysis such as Brunnaer-Emmett-Teller (BET) surface area, Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and X-ray Photoelectron Spectroscopy (XPS). The batch adsorption test of Bentonite and B-nZVI with heavy metals solutions (Pb, Cu, Cd, Co, Ni and Zn) was also conducted to determine their effectiveness in removing heavy metals. Through Batch test, B-nZVI shows the highest adsorption capacity (qe= 50.25 mg/g) compared to bentonite (qe= 27.75 mg/g). This occurred because B-nZVI can reduce aggregation of nZVI, dispersed well in bentonite layers thus it can provide more sites for adsorbing heavy metals.

Fabricating bio-inspired micro/nano-particles by polydopamine coating and surface interactions with blood platelets

Energy Technology Data Exchange (ETDEWEB)

Ye, Wei [Jiangsu Provincial Key Lab for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Shi, Qiang, E-mail: shiqiang@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Hou, Jianwen; Gao, Jian; Li, Chunming; Jin, Jing; Shi, Hengchong [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin, Jinghua, E-mail: yinjh@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2015-10-01

Graphical abstract: The particles or particle aggregations activate the blood platelets and provide the physical adhesive sites for platelets adhesion. - Highlights: • Particles with varied sizes and surface properties were fabricated by facile polydopamine (PDA) coating on polystyrene microsphere. • The direct interaction between PDA particles and blood platelets was qualitatively investigated. • The knowledge on platelet–particle interactions provided the basic principle to select biocompatible micro/nano-particles in biomedical field. - Abstract: Although bio-inspired polydopamine (PDA) micro/nano-particles show great promise for biomedical applications, the knowledge on the interactions between micro/nano-particles and platelets is still lacking. Here, we fabricate PDA-coated micro/nano-particles and investigate the platelet–particle surface interactions. Our strategy takes the advantage of facile PDA coating on polystyrene (PS) microsphere to fabricate particles with varied sizes and surface properties, and the chemical reactivity of PDA layers to immobilize fibrinogen and bovine serum albumin to manipulate platelet activation and adhesion. We demonstrate that PS particles activate the platelets in the size-dependent manner, but PDA nanoparticles have slight effect on platelet activation; PS particles promote platelet adhesion while PDA particles reduce platelet adhesion on the patterned surface; Particles interact with platelets through activating the glycoprotein integrin receptor of platelets and providing physical sites for initial platelet adhesion. Our work sheds new light on the interaction between platelets and particles, which provides the basic principle to select biocompatible micro/nano-particles in biomedical field.

Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study.

OpenAIRE

Midander, Klara; Cronholm, Pontus; Karlsson, Hanna L.; Elihn, Karine; Moller, Lennart; Leygraf, Christofer; Wallinder, Inger Odnevall

2009-01-01

An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered ...

Combustion synthesis of CaSc2O4:Ce3+ nano-phosphors in a closed system

International Nuclear Information System (INIS)

Peng Wenfang; Zou Shaoyu; Liu Guanxi; Xiao Quanlan; Zhang Rui; Xie Lijuan; Cao Liwei; Meng Jianxin; Liu Yingliang

2011-01-01

Highlights: → CaSc 2 O 4 :Ce 3+ nano-phosphors can be prepared by a single-step combustion method. → The ignition temperature is the lowest in the combustion synthesis of Ce 3+ /Eu 2+ doped phosphors. → The as-prepared nano-phosphors give a uniform particle size in the range of 15-20 nm and have highly dispersity and fluorescence intensity. → It is a convenient method for preparation of monodispersed oxide nano-phosphors, especially those being sensitive to air at high temperature. - Abstract: The CaSc 2 O 4 :Ce 3+ nano-phosphors were successfully prepared by a single-step combustion method at an ignition temperature as low as 200 deg. C in a closed autoclave using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results revealed that CaSc 2 O 4 :Ce 3+ nano-phosphors can be conveniently prepared at an ignition temperature as low as 200 deg. C, which was much lower than that in the ordinary combustion methods. The optimized ignition temperature was 220 deg. C. The CaSc 2 O 4 :Ce 3+ nano-phosphors give a uniform particle size in the range of 15-20 nm. The low ignition temperature and the addition of PEG4000 dispersant play important roles in the formation of small sized nanoparticles. The as-prepared nano-phosphors were incompact aggregates, but highly dispersed nano-phosphors can be obtained after further ultrasonic treatment. The CaSc 2 O 4 :Ce 3+ nano-phosphors give satisfactory luminescence characteristic benefiting from the closed circumstance, in which cerium atoms can be isolated from the oxidizing atmosphere and non-fluorescent Ce 4+ ions can be ruled out. The present highly dispersed CaSc 2 O 4 :Ce 3+ nano-phosphors with efficient fluorescence are promising in the field of biological labeling, and the present low temperature combustion method is facile and convenient and can

Synthesis of Nickel and Nickel Hydroxide Nano powders by Simplified Chemical Reduction

International Nuclear Information System (INIS)

Tientong, J.; Garcia, S.; Thurber, C.R.; Golden, T.D.

2014-01-01

Nickel nano powders were synthesized by a chemical reduction of nickel ions with hydrazine hydrate at ph ∼ 12.5. Sonication of the solutions created a temperature of 54-65 °C to activate the reduction reaction of nickel nanoparticles. The solution ph affected the composition of the resulting nanoparticles. Nickel hydroxide nanoparticles were formed from an alkaline solution (ph ∼10) of nickel-hydrazine complexed by dropwise titration. X-ray diffraction of the powder and the analysis of the resulting Williamson-Hall plots revealed that the particle size of the powders ranged from 12 to 14 nm. Addition of polyvinylpyrrolidone into the synthesis decreased the nickel nanoparticle size to approximately 7 nm. Dynamic light scattering and scanning electron microscopy confirmed that the particles were in the nanometer range. The structure of the synthesized nickel and nickel hydroxide nanoparticles was identified by X-ray diffraction and Fourier transform infrared spectroscopy.

Synthesis of metal-organic framework films by pore diffusion method

Science.gov (United States)

Murayama, Naohiro; Nishimura, Yuki; Kajiro, Hiroshi; Kishida, Satoru; Kinoshita, Kentaro; Tottori Univ Team; Nippon Steel; Sumitomo Metal Co. Collaboration; Tottori Integrated Frontier Resaerch Center (Tifrec) Collaboration; Tottori University Electronic Display Resaerch Center (Tedrec) Collaboration

Metal-organic frameworks (MOFs) presents high controllability in designing the nano-scale pore, and this enable molecular storages, catalysts, gas sensors, gas separation membranes, and electronic devices for next-generation. Therefore, a simple method for film synthesis of MOFs compared with conventional methods [1] is strongly required. In this paper, we provide pore diffusion method, in which a substrate containing constituent metals of MOF is inserted in solution that includes only linker molecules of MOF. As a result, 2D growth of MOF was effectively enhanced, and the formation of flat and dense MOF films was attained. The growth time, t, dependence of film thickness, d, can be expressed by the relation of d = Aln(t + 1) + B, where A and B are constants. It means that ionized coppers diffuse through the pores of MOFs and the synthesis reaction proceeds at the MOF/solvent interface. We demonstrated the fabrication of a HKUST-1/Cu-TPA hetero structure by synthesizing a Cu-TPA film continuously after the growth of a HKUST-1 film on the CuOx substrate.

Directive properties of active coated nano-particles

DEFF Research Database (Denmark)

Arslanagic, Samel; Ziolkowski, W.

2012-01-01

and optical gain constant on the directivities. While significant variations in the directivities are realized in the cylindrical cases for different source locations within and slightly outside the nano-particles and values of the optical gain constant, the corresponding spherical cases exhibit negligible...

Introduction of Nickel Coated Silicon Carbide Particles in Aluminum Metal Matrix Hardfaced by MIG/TIG Processes on Precoated Flux Layer

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V. Kamburov

2018-03-01

Full Text Available The aim of the study was to investigate an aluminium metal matrix surface layer hardfaced by shielded gas metal arc welding processes applying either metal inert gas (MIG or tungsten inert gas (TIG, with standard wire filler onto the precoated flux layer - a baked resistant film containing electroless nickel coated micro/nano SiC particles. During baking, the components of the flux (MgCl2, NaCl, KCl and Na3AlF6 form a low melting eutectic, which: protects the hardfaced surface from oxidation, provides electrical conductance and keeps the particles on the surface during welding, as well as facilitates particles wettability and their interfacial bonding with the molten metal into the weld puddle.

In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles.

Science.gov (United States)

Heravi, Farzin; Ramezani, Mohammad; Poosti, Maryam; Hosseini, Mohsen; Shajiei, Arezoo; Ahrari, Farzaneh

2013-01-01

Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2) nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco's Modified Eagle's Medium (DMEM). The extracts were obtained and exposed to culture media of human gingival fibroblasts (HGF) and mouse L929 fibroblasts. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results. Both adhesives were moderately toxic for HGF cells on the first day of the experiment, but the TiO2-containing adhesive produced significantly lower toxicity than the pure adhesive (P0.05). There was a significant reduction in cell toxicity with increasing pre-incubation time (Porthodontic adhesive containing TiO2 nano-particles indicated comparable or even lower toxicity than its nano-particle-free counterpart, indicating that incorporation of 1 wt% TiO2 nano-particles to the composite structure does not result in additional health hazards compared to that occurring with the pure adhesive.

Synthesis and applications of one-dimensional nano-structured polyaniline: An overview

International Nuclear Information System (INIS)

Zhang Donghua; Wang Yangyong

2006-01-01

This paper summarizes and reviews the various synthesizing approaches of one-dimensional nano-structured polyaniline (PANI) and several potential applications of the nanomaterial. The synthesizing approaches can be generally categorized into template synthesis and non-template synthesis according to whether template(s), hard (physical template) or soft (chemical template), is (are) used or not. However, though the various approaches established, preparation of one-dimensional nano-structured PANI with controllable morphologies and sizes, especially well oriented arrays on a large scale is still a major challenge. Furthermore, the formation mechanisms of the nanostructures are still unclear. On the other hand, one-dimensional nano-structured PANI exhibits high surface area, high conductivity, as well as controllable chemical/physical properties and good environmental stability, rendering the nanomaterial promising candidate for application ranging from sensors, energy storage and flash welding to digital nonvolatile memory

Fabrication, Characterization, and Biological Activity of Avermectin Nano-delivery Systems with Different Particle Sizes

Science.gov (United States)

Wang, Anqi; Wang, Yan; Sun, Changjiao; Wang, Chunxin; Cui, Bo; Zhao, Xiang; Zeng, Zhanghua; Yao, Junwei; Yang, Dongsheng; Liu, Guoqiang; Cui, Haixin

2018-01-01

Nano-delivery systems for the active ingredients of pesticides can improve the utilization rates of pesticides and prolong their control effects. This is due to the nanocarrier envelope and controlled release function. However, particles containing active ingredients in controlled release pesticide formulations are generally large and have wide size distributions. There have been limited studies about the effect of particle size on the controlled release properties and biological activities of pesticide delivery systems. In the current study, avermectin (Av) nano-delivery systems were constructed with different particle sizes and their performances were evaluated. The Av release rate in the nano-delivery system could be effectively controlled by changing the particle size. The biological activity increased with decreasing particle size. These results suggest that Av nano-delivery systems can significantly improve the controllable release, photostability, and biological activity, which will improve efficiency and reduce pesticide residues.

Adsorption of heavy metal ion from aqueous solution by nickel oxide nano catalyst prepared by different methods

Directory of Open Access Journals (Sweden)

Amira M. Mahmoud

2015-03-01

Full Text Available Environmental pollution by heavy metal is arising as the most endangering tasks to both water sources and atmosphere quality today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. To limit the spread of the heavy metals within water sources, nickel oxide nanoparticles adsorbents were synthesized and characterized with the aim of removal of one of the aggressive heavy elements, namely; lead ions. Nano nickel oxide adsorbents were prepared using NaOH and oxalic acid dissolved in ethanol as precursors. The results indicated that adsorption capacity of Pb(II ion by NiO-org catalyst is favored than that prepared using NaOH as a precipitant. Nickel oxide nanoparticles prepared by the two methods were characterized structurally and chemically through XRD, DTA, TGA, BET and FT-IR. Affinity and efficiency sorption parameters of the solid nano NiO particles, such as; contact time, initial concentration of lead ions and the dosage of NiO nano catalyst and competitive adsorption behaviors were studied. The results showed that the first-order reaction law fit the reduction of lead ion, also showed good linear relationship with a correlation coefficient (R2 larger than 0.9.

Nervous System Injury in Response to Contact With Environmental, Engineered and Planetary Micro- and Nano-Sized Particles

Directory of Open Access Journals (Sweden)

Tatiana Borisova

2018-06-01

Full Text Available Nerve cells take a special place among other cells in organisms because of their unique function mechanism. The plasma membrane of nerve cells from the one hand performs a classical barrier function, thereby being foremost targeted during contact with micro- and nano-sized particles, and from the other hand it is very intensively involved in nerve signal transmission, i.e., depolarization-induced calcium-dependent compound exocytosis realized via vesicle fusion following by their retrieval and calcium-independent permanent neurotransmitter turnover via plasma membrane neurotransmitter transporters that utilize Na+/K+ electrochemical gradient as a driving force. Worldwide traveling air pollution particulate matter is now considered as a possible trigger factor for the development of a variety of neuropathologies. Micro- and nano-sized particles can reach the central nervous system during inhalation avoiding the blood–brain barrier, thereby making synaptic neurotransmission extremely sensitive to their influence. Neurosafety of environmental, engineered and planetary particles is difficult to predict because they possess other features as compared to bulk materials from which the particles are composed of. The capability of the particles to absorb heavy metals and organic neurotoxic molecules from the environment, and moreover, spontaneously interact with proteins and lipids in organisms and form biomolecular corona can considerably change the particles‘ features. The absorption capability occasionally makes them worldwide traveling particulate carriers for delivery of environmental neurotoxic compounds to the brain. Discrepancy of the experimental data on neurotoxicity assessment of micro- and nano-sized particles can be associated with a variability of systems, in which neurotoxicity was analyzed and where protein components of the incubation media forming particle biocorona can significantly distort and even eliminate factual particle

Omega-3 PUFA concentration by a novel PVDF nano-composite membrane filled with nano-porous silica particles.

Science.gov (United States)

Ghasemian, Samaneh; Sahari, Mohammad Ali; Barzegar, Mohsen; Ahmadi Gavlighi, Hasan

2017-09-01

In this study, polyvinylidene fluoride (PVDF) and nano-porous silica particle were used to fabricate an asymmetric nano-composite membrane. Silica particles enhanced the thermal stability of PVDF/SiO 2 membranes; increasing the decomposition temperature from 371°C to 408°C. Cross sectional morphology showed that silica particles were dispersed in polymer matrix uniformly. However, particle agglomeration was found at higher loading of silica (i.e., 20 by weight%). The separation performance of nano-composite membranes was also evaluated using the omega-3 polyunsaturated fatty acids (PUFA) concentration at a temperature and pressure of 30°C and 4bar, respectively. Silica particle increased the omega-3PUFA concentration from 34.8 by weight% in neat PVDF to 53.9 by weight% in PVDF with 15 by weight% of silica. Moreover, PVDF/SiO 2 nano-composite membranes exhibited enhanced anti-fouling property compared to neat PVDF membrane. Fouling mechanism analysis revealed that complete pore blocking was the predominant mechanism occurring in oil filtration. The concentration of omega-3 polyunsaturated fatty acids (PUFA) is important in the oil industries. While the current methods demand high energy consumptions in concentrating the omega-3, membrane separation technology offers noticeable advantages in producing pure omega-3 PUFA. Moreover, concentrating omega-3 via membrane separation produces products in the triacylglycerol form which possess better oxidative stability. In this work, the detailed mechanisms of fouling which limits the performance of membrane separation were investigated. Incorporating silica particles to polymeric membrane resulted in the formation of mixed matrix membrane with improved anti-fouling behaviour compared to the neat polymeric membrane. Hence, the industrial potential of membrane processing to concentrate omega-3 fatty acids is enhanced. Copyright © 2017. Published by Elsevier Ltd.

Ecofriendly Synthesis of nano Zero Valent Iron from Banana Peel Extract

Science.gov (United States)

Sunardi; Ashadi; Budi Rahardjo, Sentot; Inayati

2017-01-01

In this study, nano Zero Valent Iron (nZVI) were synthesized from banana peel extract (BPE) and ferrous sulfate. During the synthesis of nZVI both the precursor and the reducing agent were mixed in a clean sterilized flask in 1:1 proportion. For the reduction of Fe ions, 5 ml of filtered BPE was mixed to 5 ml of freshly prepared 0.001 M - 0.005 M aqueous of FeSO4 solution with constant stirring at room temperature. Within a particular time change in colour from brown to black color obtained by nanoparticles synthesis. A systematic characterization of nZVI was performed using UV-Vis. UV-visible absorption is used to investigate SPR. Characteristic surface plasmon absorption band was observed at 210 nm for the black colored nZVI synthesized from 0.001-0.005 M ferrous sulfate with BPE concentration 5 ml. It has been found that the optimum concentration for the synthesis of nZVI is 0.001M Fe2+ ions. There is small decrease in the intensity of SPR band from 0.001 to 0.005 M. The characterization size of nZVI was performed using TEM. The result shows that formation of particles size of nZVI was more 100 nm.

Ecofriendly Synthesis of nano Zero Valent Iron from Banana Peel Extract

International Nuclear Information System (INIS)

Sunardi; Ashadi; Rahardjo, Sentot Budi; Inayati

2017-01-01

In this study, nano Zero Valent Iron (nZVI) were synthesized from banana peel extract (BPE) and ferrous sulfate. During the synthesis of nZVI both the precursor and the reducing agent were mixed in a clean sterilized flask in 1:1 proportion. For the reduction of Fe ions, 5 ml of filtered BPE was mixed to 5 ml of freshly prepared 0.001 M – 0.005 M aqueous of FeSO 4 solution with constant stirring at room temperature. Within a particular time change in colour from brown to black color obtained by nanoparticles synthesis. A systematic characterization of nZVI was performed using UV-Vis. UV–visible absorption is used to investigate SPR. Characteristic surface plasmon absorption band was observed at 210 nm for the black colored nZVI synthesized from 0.001–0.005 M ferrous sulfate with BPE concentration 5 ml. It has been found that the optimum concentration for the synthesis of nZVI is 0.001M Fe 2+ ions. There is small decrease in the intensity of SPR band from 0.001 to 0.005 M. The characterization size of nZVI was performed using TEM. The result shows that formation of particles size of nZVI was more 100 nm. (paper)

Temperature dependent and applied field strength dependent magnetic study of cobalt nickel ferrite nano particles: Synthesized by an environmentally benign method

Science.gov (United States)

Sontu, Uday Bhasker; G, Narsinga Rao; Chou, F. C.; M, V. Ramana Reddy

2018-04-01

Spinel ferrites have come a long way in their versatile applications. The ever growing applications of these materials demand detailed study of material properties and environmental considerations in their synthesis. In this article, we report the effect of temperature and applied magnetic field strength on the magnetic behavior of the cobalt nickel ferrite nano powder samples. Basic structural properties of spinel ferrite nano particles, that are synthesized by an environmentally benign method of auto combustion, are characterized through XRD, TEM, RAMAN spectroscopy. Diffuse Reflectance Spectroscopy (DRS) is done to understand the nickel substitution effect on the optical properties of cobalt ferrite nano particles. Thermo magnetic studies using SQUID in the temperature range 5 K to 400 K and room temperature (300 K) VSM studies are performed on these samples. Fields of 0Oe (no applied field: ZF), 1 kOe (for ZFC and FC curves), 5 kOe (0.5 T), 50 kOe (5T) (for M-H loop study) are used to study the magnetic behavior of these nano particles. The XRD,TEM analysis suggest 40 nm crystallites that show changes in the cation distribution and phase changes in the spinel structure with nickel substitution. Raman micrographs support phase purity changes and cation redistributions with nickel substitution. Diffuse reflectance study on powder samples suggests two band gap values for nickel rich compounds. The Magnetic study of these sample nano particles show varied magnetic properties from that of hard magnetic, positive multi axial anisotropy and single-magnetic-domain structures at 5 K temperature to soft magnetic core shell like structures at 300 K temperature. Nickel substitution effect is non monotonous. Blocking temperature of all the samples is found to be higher than the values suggested in the literature.

Controlled Synthesis of Manganese Dioxide Nano structures via a Facile Hydrothermal

International Nuclear Information System (INIS)

Pang, R.S.C.; Chin, S.F.; Ye, Ch. Ling

2012-01-01

Manganese dioxide nano structures with controllable morphological structures and crystalline phases were synthesized via a facile hydrothermal route at low temperatures without using any templates or surfactants. Both the aging duration and aging temperatures were the main synthesis parameters used to influence and control the rate of morphological and structural evolution of MnO 2 nano structures. MnO 2 nano structures comprise of spherical nano particulate agglomerates and highly amorphous in nature were formed at lower temperature and/or short aging duration. In contrast, MnO 2 nano structures of sea-urchin-like and nano rods-like morphologies and nanocrystalline in nature were prepared at the combined higher aging temperatures and longer aging durations. These nano structures underwent notable phase transformation from d-MnO 2 to a-MnO 2 upon prolonged hydrothermal aging duration and exhibited accelerated rate of phase transformation at higher aging temperature.

Thorium/uranium mixed oxide nano-crystals: Synthesis, structural characterization and magnetic properties

International Nuclear Information System (INIS)

Hudry, Damien; Griveau, Jean-Christophe; Apostolidis, Christos; Colineau, Eric; Rasmussen, Gert; Walter, Olaf; Wang, Di; Venkata Sai Kiran Chakravadhaluna; Courtois, Eglantine; Kubel, Christian

2014-01-01

One of the primary aims of the actinide community within nano-science is to develop a good understanding similar to what is currently the case for stable elements. As a consequence, efficient, reliable and versatile synthesis techniques dedicated to the formation of new actinide-based nano-objects (e.g., nano-crystals) are necessary. Hence, a 'library' dedicated to the preparation of various actinide based nano-scale building blocks is currently being developed. Nano-scale building blocks with tunable sizes, shapes and compositions are of prime importance. So far, the non-aqueous synthesis method in highly coordinating organic media is the only approach which has demonstrated the capability to provide size and shape control of actinide-based nano-crystals (both for thorium and uranium, and recently extended to neptunium and plutonium). In this paper, we demonstrate that the non-aqueous approach is also well adapted to control the chemical composition of the nano-crystals obtained when mixing two different actinides. Indeed, the controlled hot co-injection of thorium acetylacetonate and uranyl acetate (together with additional capping agents) into benzyl ether can be used to synthesize thorium/uranium mixed oxide nano-crystals covering the full compositional spectrum. Additionally, we found that both size and shape are modified as a function of the thorium/uranium ratio. Finally, the magnetic properties of the different thorium/uranium mixed oxide nano-crystals were investigated. Contrary to several reports, we did not observe any ferromagnetic behavior. As a consequence, ferromagnetism cannot be described as a universal feature of nano-crystals of non-magnetic oxides as recently claimed in the literature. (authors)

Synthesis and characterization of a-site doped LaTiO3 nano perovskites

International Nuclear Information System (INIS)

Bradha, M.; Ashok, Anuradha

2013-01-01

Nano-sized lanthanum titanate perovskites (La (1-x) A x TiO 3 ) (A= Ba, Sr, Ca) were prepared by sol-gel method and calcined at 800℃. The synthesised perovskites were characterized by Thermogravimetry/ Differential thermal analysis (TGA/DTA), X-ray diffraction (XRD) and High Resolution Transmission Electron Microscopy (HRTEM) etc. LaTiO 3 is a perovskite having prominent interest for a variety of applications such as dielectric, insulators, charge-transport properties etc. It is a defect perovskite, with transport properties varying from insulating to metallic based on oxygen stoichiometry. In a quest to observe the effect of the nano size on its properties, lanthanum titanate (LaTiO 3 ) nano perovskites with different dopants on the A-site were prepared by using sol-gel method. In the present work we discuss the synthesis and structural analysis of (La 0.8 A 0.2 TiO 3 ). Phase purity and structural analysis of the calcined samples were performed by powder X-ray diffraction (XRD, with CuKα radiation). In addition to this, morphology and crystal structure was examined by Transmission Electron Microscopy (TEM) using a JEOL JEM 2100 HRTEM. HRTEM studies indicate that the nano perovskites are of size around 20 nm. Ring pattern in SAED also confirms that the perovskite is polycrystalline/nanocrystalline. More detailed study on high resolution images and crystal structure shed light on the reason for the properties exhibited by this perovskites

Nano-metal Oxides: Exposure and Engineering Control Assessment

OpenAIRE

Garcia, Alberto; Sparks, Christopher; Martinez, Kenneth; Topmiller, Jennifer L.; Eastlake, Adrienne; Geraci, Charles L.

2017-01-01

This paper discusses the evaluation of a facility that produces high quality engineered nanomaterials. These ENMs consist of various metals including iron, nickel, silver, manganese, and palladium. Although occupational exposure levels are not available for these metals, studies have indicated that it may be prudent to keep exposures to the nano-scale metal as low as possible. Previous In vitro studies indicated that in comparison with a material’s larger (parent) counterpart, nanomaterials c...

Monitoring of magnetic nano-particles in EOR by using the CSEM modeling and inversion.

Science.gov (United States)

Heo, J. Y.; KIM, S.; Jeong, G.; Hwang, J.; Min, D. J.

2016-12-01

EOR, which injects water, CO2, or other chemical components into reservoirs to increase the production rate of oil and gas, has widely been used. To promote efficiency of EOR, it is important to monitor distribution of injected materials in reservoirs. Using nano-particles in EOR has advantages that the size of particles is smaller than the pore and particles can be characterized by various physical properties. Specifically, if we use magnetic nano-particles, we can effectively monitor nano-particles by using the electromagnetic survey. CSEM, which can control the frequency range of source, is good to monitor magnetic nano-particles under various reservoir circumstances. In this study, we first perform numerical simulation of 3D CSEM for reservoir under production. In general, two wells are used for EOR: one is for injection, and the other is for extraction. We assume that sources are applied inside the injection well, and receivers are deployed inside the extraction well. To simulate the CSEM survey, we decompose the total fields into primary and secondary fields in Maxwell's equations. For the primary fields, we calculate the analytic solutions of the layered earth. With the calculated primary fields, we compute the secondary fields due to anomalies using the edge-based finite-element method. Finally, we perform electromagnetic inversion for both conductivity and permeability to trace the distribution of magnetic nano-particles. Since these two parameters react differently according to the frequency range of sources, we can effectively describe the distribution of magnetic nano-particles by considering two parameters at the same time. Acknowledgements This work was supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP) and the Ministry of Trade, Industry & Energy(MOTIE) of the Republic of Korea (No. 20168510030830), and by the International Cooperation (No. 2012-8510030010) of KETEP, and by the Dual Use Technology Program, granted

Studies on Thermal Decomposition of Aluminium Sulfate to Produce Alumina Nano Structure

Directory of Open Access Journals (Sweden)

M. Jafar-Tafreshi

2012-12-01

Full Text Available Aluminum sulfate nano structures have been prepared by solution combustion synthesis using aluminum nitrate nonahydrate (Al(NO33.9H2O and ammonium sulfate ((NH42SO4. The resultant aluminum sulfate nano structures were calcined at different temperatures to study thermal  decomposition of aluminum sulfate. The crystallinity and phase of  the as-synthesized and calcined samples were characterized by both X- ray diffraction and FTIR measurements. These two analyses determined the temperature at which the aluminum sulfate is converted to γ-alumina nano particles. The specific surface area and pore size distribution for  γ-alumina nano particles were determined by BET measurement. TEM measurement confirmed the size of the particles obtained by XRD and BET analyses.

Hydroxyapatite nucleated and grown on nano titania particles enhances recruitment of Escherichia coli for subsequent photocatalytic elimination

International Nuclear Information System (INIS)

Huang, Jing; Liu, Yi; Liu, Yuxin; Li, Hua

2015-01-01

Titania-hydroxyapatite (HA) nanocomposites were fabricated by wet chemical synthesis approach. HA exhibited crystallographic orientation of nucleation on nano titania particle, forming the composite particles with titania being partially enwrapped with HA. Microstructural characterization by high resolution transmission electron microscopy revealed coherent interfacial bond of (110) and (222) planes of HA crystal with (101) plane of anatase. The HA layer promoted significantly recruitment of Escherichia coli bacteria onto the titania-based particles for subsequent photocatalytic killing. Less extent of enwrapping of HA on titania particle, as accomplished by increasing the aging time of HA suspension, gave rise to better capability of photocatalytic degradation of methylene blue and sterilization of the bacteria. The novel HA-enwrapped titania powder shows great potential for environmental applications. - Highlights: • Titania-hydroxyapatite nanocomposite powder was fabricated with cladding structure. • Hydroxyapatite nucleated and grew on titania particle with preferred orientation. • Hydroxyapatite layer promotes recruitment of Escherichia coli onto titania-based particles. • The titania-hydroxyapatite particles show excellent antibacterial performances. • The nanocomposite powder exhibits excellent photocatalytic performances

Hydroxyapatite nucleated and grown on nano titania particles enhances recruitment of Escherichia coli for subsequent photocatalytic elimination

Energy Technology Data Exchange (ETDEWEB)

Huang, Jing; Liu, Yi; Liu, Yuxin; Li, Hua, E-mail: lihua@nimte.ac.cn

2015-02-01

Titania-hydroxyapatite (HA) nanocomposites were fabricated by wet chemical synthesis approach. HA exhibited crystallographic orientation of nucleation on nano titania particle, forming the composite particles with titania being partially enwrapped with HA. Microstructural characterization by high resolution transmission electron microscopy revealed coherent interfacial bond of (110) and (222) planes of HA crystal with (101) plane of anatase. The HA layer promoted significantly recruitment of Escherichia coli bacteria onto the titania-based particles for subsequent photocatalytic killing. Less extent of enwrapping of HA on titania particle, as accomplished by increasing the aging time of HA suspension, gave rise to better capability of photocatalytic degradation of methylene blue and sterilization of the bacteria. The novel HA-enwrapped titania powder shows great potential for environmental applications. - Highlights: • Titania-hydroxyapatite nanocomposite powder was fabricated with cladding structure. • Hydroxyapatite nucleated and grew on titania particle with preferred orientation. • Hydroxyapatite layer promotes recruitment of Escherichia coli onto titania-based particles. • The titania-hydroxyapatite particles show excellent antibacterial performances. • The nanocomposite powder exhibits excellent photocatalytic performances.

Control of the Nano-Particle Weight Ratio in Stainless Steel Micro and Nano Powders by Radio Frequency Plasma Treatment

OpenAIRE

Dong-Yeol Yang; Youngja Kim; Min Young Hur; Hae June Lee; Yong-Jin Kim; Tae-Soo Lim; Ki-Bong Kim; Sangsun Yang

2015-01-01

This study describes how to make stainless steel hybrid micro-nano-powders (a mixture of micro-powder and nano-powder) using an in situ one-step process via radio frequency (RF) thermal plasma treatment. Nano-particles attached to micro-powders were successfully prepared by RF thermal plasma treatment of stainless steel powder with an average size of 35 μm. The ratio of nano-powders is estimated with a two-dimensional fluid simulation that calculates the temperature profile influencing the r...

Optical Detection and Sizing of Single Nano-Particles Using Continuous Wetting Films

Science.gov (United States)

Hennequin, Yves; McLeod, Euan; Mudanyali, Onur; Migliozzi, Daniel; Ozcan, Aydogan; Dinten, Jean-Marc

2013-01-01

The physical interaction between nano-scale objects and liquid interfaces can create unique optical properties, enhancing the signatures of the objects with sub-wavelength features. Here we show that the evaporation on a wetting substrate of a polymer solution containing sub-micrometer or nano-scale particles creates liquid micro-lenses that arise from the local deformations of the continuous wetting film. These micro-lenses have properties similar to axicon lenses that are known to create beams with a long depth of focus. This enhanced depth of focus allows detection of single nanoparticles using a low magnification microscope objective lens, achieving a relatively wide field-of-view, while also lifting the constraints on precise focusing onto the object plane. Hence, by creating these liquid axicon lenses through spatial deformations of a continuous thin wetting film, we transfer the challenge of imaging individual nano-particles to detecting the light focused by these lenses. As a proof of concept, we demonstrate the detection and sizing of single nano-particles (100 and 200 nm), CpGV granuloviruses as well as Staphylococcus epidermidis bacteria over a wide field of view of e.g., 5.10×3.75 mm2 using a ×5 objective lens with a numerical aperture of 0.15. In addition to conventional lens-based microscopy, this continuous wetting film based approach is also applicable to lensfree computational on-chip imaging, which can be used to detect single nano-particles over a large field-of-view of e.g., >20-30 mm2. These results could be especially useful for high-throughput field-analysis of nano-scale objects using compact and cost-effective microscope designs. PMID:23889001

Concrete surface with nano-particle additives for improved wearing resistance to increasing truck traffic.

Science.gov (United States)

2012-07-01

This study focused on the use of nanotechnology in concrete to improve the wearing resistance of concrete. The nano : materials used were polymer cross-linked aerogels, carbon nanotubes, and nano-SiO2, nano-CaCO3, and nano-Al2O3 : particles. As an in...

In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

Directory of Open Access Journals (Sweden)

Farzin Heravi

2013-12-01

Full Text Available Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2 nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco’s Modified Eagle’s Medium (DMEM. The extracts were obtained and exposed to culture media of human gingival fibroblasts (HGF and mouse L929 fibroblasts. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results. Both adhesives were moderately toxic for HGF cells on the first day of the experiment, but the TiO2-containing adhesive produced significantly lower toxicity than the pure adhesive (P0.05. There was a significant reduction in cell toxicity with increasing pre-incubation time (P<0.001. L929 cells showed similar toxicity trends, but lower sensitivity to detect cytotoxicity of dental composites. Conclusion. The orthodontic adhesive containing TiO2 nano-particles indicated comparable or even lower toxicity than its nano-particle-free counterpart, indicating that incorporation of 1 wt% TiO2 nano-particles to the composite structure does not result in additional health hazards compared to that occurring with the pure adhesive.

Synthesis of hydroxyapatite particles in catanionic mixed surfactants template

International Nuclear Information System (INIS)

Tari, Nesa Esmaeilian; Kashani Motlagh, Mohammad M.; Sohrabi, Beheshteh

2011-01-01

Highlights: ►The mixture of cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) with different ratio were used as the template for synthesizing HAP particles. ► The overall morphology of the obtained powders at anionic-rich region (SDS:CTAB, 99:1) solution is rod like with high regularity. ► In the presence of cationic rich region (SDS:CTAB, 1:99) the resulted particles was sheet like. ► The resulted HAP nano particles in the presence of SDS were rod like but their morphology was less oriented than anionic-rich region. - Abstract: Different morphologies of nano hydroxyapatite particles, Ca 10 (PO 4 ) 6 (OH) 2 (HAP) are prepared by precipitation method using CaCl 2 and H 3 PO 4 (water phase) and the mixture of cationic surfactant cetyltrimethyl ammonium bromide (CTAB) and anionic one sodium dodecyl sulfate (SDS) as template. The mixture of these surfactants in two regions of cationic-rich and anionic-rich form the various aggregations as template. The results show that by changing the ratio of cationic to anionic surfactant in the mixture the morphology of the nano HAP can be controlled. The nano structure of products is studied by the means of X-ray diffraction (XRD), Fourier transmission infrared spectrometer (FT-IR) and scanning electron microscopy (SEM). With this system we could synthesize nano particles of hydroxyapatite with high crystallinity and least agglomeration.

Synthesis of hydroxyapatite particles in catanionic mixed surfactants template

Energy Technology Data Exchange (ETDEWEB)

Tari, Nesa Esmaeilian [Department of Chemistry, Iran University of Science and Technology, Resalat Square, Hengam Street, Tehran (Iran, Islamic Republic of); Kashani Motlagh, Mohammad M., E-mail: M.Kashani@iust.ac.ir [Department of Chemistry, Iran University of Science and Technology, Resalat Square, Hengam Street, Tehran (Iran, Islamic Republic of); Sohrabi, Beheshteh [Department of Chemistry, Iran University of Science and Technology, Resalat Square, Hengam Street, Tehran (Iran, Islamic Republic of)

2011-12-15

Highlights: Black-Right-Pointing-Pointer The mixture of cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) with different ratio were used as the template for synthesizing HAP particles. Black-Right-Pointing-Pointer The overall morphology of the obtained powders at anionic-rich region (SDS:CTAB, 99:1) solution is rod like with high regularity. Black-Right-Pointing-Pointer In the presence of cationic rich region (SDS:CTAB, 1:99) the resulted particles was sheet like. Black-Right-Pointing-Pointer The resulted HAP nano particles in the presence of SDS were rod like but their morphology was less oriented than anionic-rich region. - Abstract: Different morphologies of nano hydroxyapatite particles, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} (HAP) are prepared by precipitation method using CaCl{sub 2} and H{sub 3}PO{sub 4} (water phase) and the mixture of cationic surfactant cetyltrimethyl ammonium bromide (CTAB) and anionic one sodium dodecyl sulfate (SDS) as template. The mixture of these surfactants in two regions of cationic-rich and anionic-rich form the various aggregations as template. The results show that by changing the ratio of cationic to anionic surfactant in the mixture the morphology of the nano HAP can be controlled. The nano structure of products is studied by the means of X-ray diffraction (XRD), Fourier transmission infrared spectrometer (FT-IR) and scanning electron microscopy (SEM). With this system we could synthesize nano particles of hydroxyapatite with high crystallinity and least agglomeration.

Preparation of silver nano-particles immobilized onto chitin nano-crystals and their application to cellulose paper for imparting antimicrobial activity.

Science.gov (United States)

Li, Zhihan; Zhang, Ming; Cheng, Dong; Yang, Rendang

2016-10-20

Immobilized silver nano-particles (Ag NPs) possess excellent antimicrobial properties due to their unique surface characteristics. In this paper, immobilized silver nano-particles were synthesized in the presence of chitin nano-crystals (CNC) based on the Tollens mechanism (reduction of silver ion by aldehydes in the chitosan oligosaccharides (COS)) under microwave-assisted conditions. The prepared Ag NPs-loaded CNC nano-composites were then applied onto the paper surface via coating for the preparation of antibacterial paper. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) results confirmed that the Ag NPs were immobilized onto the CNC. The transmission electron microscope (TEM) and scanning electron microscopy (SEM) results further revealed that the spherical Ag NPs (5-12nm) were well dispersed on the surface of CNC. The coated paper made from the Ag NPs-loaded CNC nano-composites exhibited a high effectiveness of the antibacterial activity against E. coli or S. aureus. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and characterization of carbon nano fibers for its application in the adsorption of toxic gases

International Nuclear Information System (INIS)

Juanico L, J.A.

2004-01-01

The production of carbon nano fibers (CNF's) by diverse techniques as the electric arc, laser ablation, or chemical deposition in vapor phase, among other, they have been so far used from final of the 90's. However, the synthesis method by discharge Glow arc of alternating current and high frequency developed by Pacheco and collaborators, is a once alternative for its obtaining. In the plasma Application Laboratory (LAP) of the National Institute of Nuclear Research (INlN) it was designed and manufactured a reactor of alternating current and high frequency that produces a Glow arc able to synthesize carbon nano fibers. Its were carried out nano fibers synthesis with different catalysts to different proportions and with distinct conditions of vacuum pressure and methane flow until obtaining the best nano fibers samples and for it, this nano structures were characterized by Scanning and Transmission Electron Microscopy, X-ray Diffraction, Raman spectrometry and EDS spectrometry. Once found the optimal conditions for the nano fibers production its were contaminated with NO 2 toxic gas and it was determined if they present adsorption, for it was used the thermal gravimetric analysis technique. This work is divided in three parts, in the first one, conformed by the chapters 1, at the 3, they are considered the foundations of the carbon nano fibers, their history, their characteristics, growth mechanisms, synthesis techniques, the thermal gravimetric analysis principles and the adsorption properties of the nano fibers. In the second part, consistent of the chapters 4 and 5, the methodology of synthesis and characterization of the nano fibers is provided. Finally, in third part its were carried out the activation energy calculation, the adsorption of the CNF's is analyzed and the conclusions are carried out. The present study evaluates the adsorption of environmental gas pollutants as the nitrogen oxides on carbon nano fibers at environmental or near conditions. Also

Forging of metallic nano-objects for the fabrication of submicron-size components

International Nuclear Information System (INIS)

Roesler, J; Mukherji, D; Schock, K; Kleindiek, S

2007-01-01

In recent years, nanoscale fabrication has developed considerably, but the fabrication of free-standing nanosize components is still a great challenge. The fabrication of metallic nanocomponents utilizing three basic steps is demonstrated here. First, metallic alloys are used as factories to produce a metallic raw stock of nano-objects/nanoparticles in large numbers. These objects are then isolated from the powder containing thousands of such objects inside a scanning electron microscope using manipulators, and placed on a micro-anvil or a die. Finally, the shape of the individual nano-object is changed by nanoforging using a microhammer. In this way free-standing, high-strength, metallic nano-objects may be shaped into components with dimensions in the 100 nm range. By assembling such nanocomponents, high-performance microsystems can be fabricated, which are truly in the micrometre scale (the size ratio of a system to its component is typically 10:1)

Microstructure and properties of SA 106B carbon steel after treatment of the melt with nano-sized TiC particles

International Nuclear Information System (INIS)

Park, Jin-Ju; Hong, Sung-Mo; Park, Eun-Kwang; Kim, Kyeong-Yeol; Lee, Min-Ku; Rhee, Chang-Kyu

2014-01-01

Carbon steel dispersed with nano-sized TiC ceramic particles was fabricated using the liquid metal casting process by means of their ex-situ introduction. For this purpose, the nano-sized TiC powders with an initial average size of 40 nm were first mechanically activated with two metal powders (Fe, Ni) and then introduced externally into the molten carbon steel during the casting process. According to the chemical composition analysis, 90% of the initial TiC nanoparticles were discovered within the cast carbon steel. Compared to cast carbon steel without TiC nanoparticles, the grain size refinement and mechanical property enhancement were achieved. Atom probe tomographic analysis revealed that the TiC nanoparticles were approximately 30 nm in size in the carbon steel matrix with a number density of 1.49×10 21 m −3

Eliminating Heavy Metals from Water with NanoSheet Minerals as Adsorbents

Directory of Open Access Journals (Sweden)

Shaoxian Song

2017-12-01

Full Text Available Heavy metals usually referred to those with atomic weights ranging from 63.5 to 200.6. Because of natural-mineral dissolution and human activities such as mining, pesticides, fertilizer, metal planting and batteries manufacture, etc., these heavy metals, including zinc, copper, mercury, lead, cadmium and chromium have been excessively released into water courses, like underground water, lake and river, etc. The ingestion of the heavy metals-contaminated water would raise serious health problems to human beings even at a low concentration. For instance, lead can bring human beings about barrier to the normal function of kidney, liver and reproductive system, while zinc can cause stomach cramps, skin irritations, vomiting and anemia. Mercury is a horrible neurotoxin that may result in damages to the central nervous system, dysfunction of pulmonary and kidney, chest and dyspnea. Chromium (VI has been proved can cause many diseases ranging from general skin irritation to severe lung carcinoma. Accordingly, the World Health Organization announced the maximum contaminant levels (MCL for the heavy metals in drinking water. There are numerous processes for eliminating heavy metals from water in order to provide citizens safe drinking water, including precipitation, adsorption, ion exchange, membrane separation and biological treatment, etc. Adsorption is considered as a potential process for deeply removing heavy metals, in which the selection of adsorbents plays a predominant role. Nano-sheet minerals as the adsorbents are currently the hottest researches in the field. They are obtained from layered minerals, such as montmorillonite, graphite and molybdenite, through the processing of intercalation, electrochemical and mechanical exfoliation, etc. Nano-sheet minerals are featured by their large specific surface area, relatively low costs and active adsorbing sites, leading to be effective and potential adsorbents for heavy metals removal from water

Solvent-Free Synthesis of Quaternary Metal Sulfide Nanoparticles Derived from Thiourea

KAUST Repository

Bhunia, Manas Kumar

2017-08-09

The synthesis of metal sulfide (MS) materials with sizes in the sub-10 nm regime often requires capping agents with long hydrocarbon chains that affect their structures and properties. Herein, this study presents a molten-state synthesis method for a series of transition-MS nanoparticles using thiourea as a reactive precursor without capping agents. This study also reports the synthesis of MS with single metals (Fe, Co, Ni, Cu, and Zn) and quaternary CuGa2In3S8 using the same synthesis protocol. Thiourea first melts to form a molten-state condition to serve as the reaction medium at a relatively low temperature (<200 °C), followed by its thermal decomposition to induce a reaction with the metal precursor to form different MS. This synthesis protocol, owing to its dynamic characteristics, involves the formation of a variety of organic carbon nitride polymeric complexes around the MS particles. Dynamic nuclear polarization surface-enhanced nuclear magnetic resonance spectroscopy is effective to identify the polymeric compositions and structures as well as their interactions with the MS. These results provided thorough structural descriptions of the MS nanoparticles surrounded by the carbon nitride species derived from thiourea, which may find various applications, including photocatalytic water splitting.

Spherical active coated nano-particles – impact of the electric Hertzian dipole orientation

DEFF Research Database (Denmark)

Arslanagic, Samel; Mostafavi, M.; Malureanu, Radu

2011-01-01

Spherical active coated nano-particles comprised of a silica nano-cylinder core covered with a plasmonic nano-shell are investigated with regard to their near- and far-field properties. The source of excitation is taken to be that of a tangential or a radial electric Hertizan dipole while three...

Synthesis of LiFePO4/Graphene Nano composite and Its Electrochemical Properties as Cathode Material for Li-Ion Batteries

International Nuclear Information System (INIS)

Ma, X.; Chen, G.; Liu, Q.; Zeng, G.; Wu, T.

2014-01-01

LiFePO 4 /graphene nano composite was successfully synthesized by rheological phase method and its electrochemical properties as the cathode materials for lithium ion batteries were measured. As the iron source in the synthesis, FeOOH nano rods anchored on graphene were first synthesized. The FeOOH nano rods precursors and the final LiFePO 4 /graphene nano composite products were characterized by XRD, SEM, and TEM. While the FeOOH precursors were nano rods with 5-10 nm in diameter and 10-50 nm in length, the LiFePO 4 were nanoparticles with 20-100 nm in size. Compared with the electrochemical properties of LiFePO 4 particles without graphene nano sheets, it is clear that the graphene nano sheets can improve the performances of LiFePO 4 as the cathode material for lithium ion batteries. The as-synthesized LiFePO 4 /graphene nano composite showed high capacities and good cyclabilities. When measured at room temperature and at the rate of 0.1 C (1 C = 170 mA g -1 ), the composite showed a discharge capacity of 156 mA h g -1 in the first cycle and a capacity retention of 96% after 15 cycles. The improved performances of the composite are believed to be the result of the three-dimensional conducting network formed by the flexible and planar graphene nano sheets.

Controlling measures of micro-plastic and nano pollutants: A short review of disposing waste toners.

Science.gov (United States)

Ruan, Jujun; Qin, Baojia; Huang, Jiaxin

2018-05-31

Micro-plastic and nano-particle have been the focal pollutants in environmental science. The printer toner is omitted micro-plastic and nano pollutant. It is comprised of micro polyacrylate styrene and nano-Fe 3 O 4 particles. Polyacrylate styrene and nano-metal were proved to be irreversibly toxic to biological cells. Therefore, toners have the potential environmental risk and healthy harm due to include micro plastics and nano-metal. To our knowledge, few studies provided the specific collection and treatment of micro-plastic pollutant. This paper has chosen a kind of micro-plastic and nano pollutant toxic toner and provided technical guidance and inspiration for controlling the micro-plastic and nano pollutants. The method of vacuum-gasification-condensation was adopted for controlling the micro-plastic and nano pollutant toner. We believe this review will open up a potential avenue for controlling micro-plastic and nano pollutants for environmental protection. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of particle size on thermal decomposition of alkali metal picrates

International Nuclear Information System (INIS)

Liu, Rui; Zhang, Tonglai; Yang, Li; Zhou, Zunning

2014-01-01

Graphical abstract: The smaller-sized picrate has greater gas emission than do its larger counterpart. The small size effect reduces the thermal decomposition activation energy, accelerates the reaction rate, and promotes the reaction activity. - Highlights: • Picrates were prepared into three micron sizes by microemulsion synthesis. • Thermal decomposition kinetics and thermodynamics were studied by DPTA and DSC. • Smaller-sized picrate has higher activity and faster reaction rate. • Particle size effect on thermal decomposition kinetics and thermodynamics was revealed. - Abstract: Three alkali metal picrates, KPA, RbPA and CsPA, were prepared into three micron sizes by microemulsion synthesis, and their thermal decomposition behaviors were investigated by DPTA at different temperatures and by DSC at different heating rates. The smaller-sized picrate has greater gas emission and smaller kinetic and thermodynamic parameters than do its larger counterpart. It can be attributed to the decreasing particle size which leads to the high surface energy, the fast mass and heat transfer, and the increasing active sites on the reaction interface. The small size effect and surface effect cause the autocatalysis which reduces the activation energy and promotes the reaction activity. The particle size does not affect the reaction mechanism. However, the picrates with different central alkali metals exhibit different reaction mechanisms even though they are of the same size. This is because the central metal determines the bond energy and consequently affects the stability of picrate

Effect of particle size on thermal decomposition of alkali metal picrates

Energy Technology Data Exchange (ETDEWEB)

Liu, Rui; Zhang, Tonglai, E-mail: ztlbit@bit.edu.cn; Yang, Li; Zhou, Zunning

2014-05-01

Graphical abstract: The smaller-sized picrate has greater gas emission than do its larger counterpart. The small size effect reduces the thermal decomposition activation energy, accelerates the reaction rate, and promotes the reaction activity. - Highlights: • Picrates were prepared into three micron sizes by microemulsion synthesis. • Thermal decomposition kinetics and thermodynamics were studied by DPTA and DSC. • Smaller-sized picrate has higher activity and faster reaction rate. • Particle size effect on thermal decomposition kinetics and thermodynamics was revealed. - Abstract: Three alkali metal picrates, KPA, RbPA and CsPA, were prepared into three micron sizes by microemulsion synthesis, and their thermal decomposition behaviors were investigated by DPTA at different temperatures and by DSC at different heating rates. The smaller-sized picrate has greater gas emission and smaller kinetic and thermodynamic parameters than do its larger counterpart. It can be attributed to the decreasing particle size which leads to the high surface energy, the fast mass and heat transfer, and the increasing active sites on the reaction interface. The small size effect and surface effect cause the autocatalysis which reduces the activation energy and promotes the reaction activity. The particle size does not affect the reaction mechanism. However, the picrates with different central alkali metals exhibit different reaction mechanisms even though they are of the same size. This is because the central metal determines the bond energy and consequently affects the stability of picrate.

Asymmetric active nano-particles for directive near-field radiation

DEFF Research Database (Denmark)

Arslanagic, Samel; Thorsen, Rasmus O.

2016-01-01

In this work, we demonstrate the potential of cylindrical active coated nano-particles with certain geometrical asymmetries for the creation of directive near-field radiation. The particles are excited by a near-by magnetic line source, and their performance characteristics are reported in terms...... of radiated power, near-field and power flow distributions as well as the far-field directivity....

Nano sized clay detected on chalk particle surfaces

DEFF Research Database (Denmark)

Skovbjerg, Lone; Hassenkam, Tue; Makovicky, Emil

2012-01-01

that in calcite saturated water, both the polar and the nonpolar functional groups adhere to the nano sized clay particles but not to calcite. This is fundamentally important information for the development of conceptual and chemical models to explain wettability alterations in chalk reservoirs...

Fiscal 1998 research report on micro-particle control process technology; 1998 nendo micro ryushi seigyo process gijutsu no chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

For establishment of process technology realizing control of forms and structures of micro-particles on practical equipment, research was made on related elementary technologies and current technologies. The research was promoted aiming at synthesis of micro-particles from nanometer to micrometer in size and their application to functional materials, establishment of the methodology for correlating the microstructure and function of micro-particle materials with fabrication process, and establishment of a common-base technology system in chemical technology aiming at fabrication of functional materials. As for the common- base technology, to clarify its importance, research was made on the fabrication method and dispersion mechanism of nano- particles, particle arraying method by coating, device fabrication technique by coating, and one-step synthesis and coating of nano-particles. As for the project research, synthesis of monodispersed nano-particles at large production rates, fabrication of thin films and bulk materials by arraying and coating. (NEDO)

Ultrafast Dynamics of Metallo-Dielectric Core-Shell Particles

NARCIS (Netherlands)

Shan, X.

2008-01-01

Optical properties of metallic nano-structures have attracted a lot of attention in the past decades. In this thesis, we focus on nano-sized silica-core gold-shell particles, study the linear, nonlinear and acoustic vibrations of the particles. The linear optical properties in the visible range of

Ultrasonic-assisted synthesis of nano lead(II) coordination polymer as precursors for preparation of lead(II) oxide nano-structures: Thermal, optical properties and XRD studies.

Science.gov (United States)

Ghavidelaghdam, Elham; Shahverdizadeh, Gholam Hossein; Motameni Tabatabai, Javad; Mirtamizdoust, Babak

2018-04-01

Nano structure of a lead (II) coordination polymer [Pb 2 (C 2 Cl 3 O 2 ) 2 (NO 3 ) 2 (C l2 H 8 N 2 ) 2 ] n (1), has been synthesized by a sonochemical method in different concentrations. The nano particles were characterized by scanning electron microscopy (SEM) X-ray powder diffraction (XRD), FT-IR spectroscopy and elemental analyses. The thermal stability of nano structure is closely investigated via thermal gravimetric (TGA), and compared with crystalline structure. The compounds are then heated to 600 °C to produce PbO nano particles. The resulting PbO is characterized through XRD and SEM analyses. Concentration of initial reagents effects on size and morphology of nano-structured compound 1 have been studied and show that low concentrations of initial reagents decreased particles size and leaded to uniform nano particles morphology. The photoluminescence properties of the prepared compound, as crystalline and as nanoparticles, have been investigated. The result showed a good correlation between the size and emission wavelength. Copyright © 2017. Published by Elsevier B.V.

Synthesis, optical properties and growth mechanism of MnO nano structures

Science.gov (United States)

Pandey, B. K.; Shahi, A. K.; Gopal, R.

2013-10-01

Manganese oxide (MnO) colloidal nanoparticles have been successfully synthesized by pulse laser ablation in double distilled water. Nd: YAG laser with focused output operating at different pulse energies (20, 30, 40, 50 mJ/pulse) was used for ablation. Synthesized MnO nano crystal phase and structure were confirmed by X-ray diffraction and SAED pattern. Optical properties of as synthesized MnO nano colloidal solution were studied by UV-vis absorption spectroscopy. Optical particle size and band gap of as synthesized MnO colloidal nanoparticles were calculated. Particle shape and size were determined by TEM/SEM image. It is observed that MnO nano colloidal particles assembled to make different structures after aging in the liquid media. Aspect ratio has been calculated from SEM picture. MnO nanoparticles show weak antiferromagnetic behavior at room temperature as measured by VSM. A typical mechanism has been proposed for the formation of different nanostructures.

A Facile Method for Separating and Enriching Nano and Submicron Particles from Titanium Dioxide Found in Food and Pharmaceutical Products

Science.gov (United States)

Yang, Yu; Capco, David G.; Westerhoff, Paul

2016-01-01

Recent studies indicate the presence of nano-scale titanium dioxide (TiO2) as an additive in human foodstuffs, but a practical protocol to isolate and separate nano-fractions from soluble foodstuffs as a source of material remains elusive. As such, we developed a method for separating the nano and submicron fractions found in commercial-grade TiO2 (E171) and E171 extracted from soluble foodstuffs and pharmaceutical products (e.g., chewing gum, pain reliever, and allergy medicine). Primary particle analysis of commercial-grade E171 indicated that 54% of particles were nano-sized (i.e., < 100 nm). Isolation and primary particle analysis of five consumer goods intended to be ingested revealed differences in the percent of nano-sized particles from 32%‒58%. Separation and enrichment of nano- and submicron-sized particles from commercial-grade E171 and E171 isolated from foodstuffs and pharmaceuticals was accomplished using rate-zonal centrifugation. Commercial-grade E171 was separated into nano- and submicron-enriched fractions consisting of a nano:submicron fraction of approximately 0.45:1 and 3.2:1, respectively. E171 extracted from gum had nano:submicron fractions of 1.4:1 and 0.19:1 for nano- and submicron-enriched, respectively. We show a difference in particle adhesion to the cell surface, which was found to be dependent on particle size and epithelial orientation. Finally, we provide evidence that E171 particles are not immediately cytotoxic to the Caco-2 human intestinal epithelium model. These data suggest that this separation method is appropriate for studies interested in isolating the nano-sized particle fraction taken directly from consumer products, in order to study separately the effects of nano and submicron particles. PMID:27798677

Linear arrangement of nano-scale magnetic particles formed in Cu-Fe-Ni alloys

Energy Technology Data Exchange (ETDEWEB)

Kang, Sung, E-mail: k3201s@hotmail.co [Department of Materials Engineering (SEISAN), Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama, 240-8501 (Japan); Takeda, Mahoto [Department of Materials Engineering (SEISAN), Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama, 240-8501 (Japan); Takeguchi, Masaki [Advanced Electron Microscopy Group, National Institute for Materials Science (NIMS), Sakura 3-13, Tsukuba, 305-0047 (Japan); Bae, Dong-Sik [School of Nano and Advanced Materials Engineering, Changwon National University, Gyeongnam, 641-773 (Korea, Republic of)

2010-04-30

The structural evolution of nano-scale magnetic particles formed in Cu-Fe-Ni alloys on isothermal annealing at 878 K has been investigated by means of transmission electron microscopy (TEM), electron dispersive X-ray spectroscopy (EDS), electron energy-loss spectroscopy (EELS) and field-emission scanning electron microscopy (FE-SEM). Phase decomposition of Cu-Fe-Ni occurred after an as-quenched specimen received a short anneal, and nano-scale magnetic particles were formed randomly in the Cu-rich matrix. A striking feature that two or more nano-scale particles with a cubic shape were aligned linearly along <1,0,0> directions was observed, and the trend was more pronounced at later stages of the precipitation. Large numbers of <1,0,0> linear chains of precipitates extended in three dimensions in late stages of annealing.

Higher order mode excitation in eccentric active nano-particles for tailoring of the near-field radiation

DEFF Research Database (Denmark)

Thorsen, R. O.; Arslanagic, Samel

2015-01-01

We examine the excitation of resonant modes inside eccentrically layered cylindrical active nano-particles. The nano-particle is a three-layer structure comprised of a silica core, a free-space middle layer, and an outer shell of silver. It is shown that a concentric configuration, initially desi...... of the gain constant, is shown to be controlled by the direction of the core displacement. The present eccentric active nano-particles may provide alternative strategies for directive near-field radiation relative to the existing designs....

Technologies for the 21st century: carbon nano tubes as adsorbents of metals

International Nuclear Information System (INIS)

Alguacil, F. J.; Cerpa, A.; Lado, I.; Lopez, F. A.

2014-01-01

Nowadays and in the recent past when the word nano appeared in almost anything it attracted immediate attention and interest, this is why carbon nano tubes, since its discovery nearly twenty years ago, caught the interest of a wide scientific and industrial population to apply the somewhat amazing properties of these nano materials in a number of applications. Among them, the removal of toxic and sometimes profitable metals from aqueous streams appeared, due to its economical and social impact, as one of the targets for their uses. This paper reviews some recent advances (2009-2013 years) in the application of carbon nano tubes materials in the removal of a variety of metals from these aqueous streams. (Author)

Chitosan-coated doxorubicin nano-particles drug delivery system inhibits cell growth of liver cancer via p53/PRC1 pathway.

Science.gov (United States)

Ye, Bai-Liang; Zheng, Ru; Ruan, Xiao-Jiao; Zheng, Zhi-Hai; Cai, Hua-Jie

2018-01-01

Nano-particles have been widely used in target-specific drug delivery system and showed advantages in cancers treatment. This study aims to evaluate the effect of chitosan coated doxorubicin nano-particles drug delivery system in liver cancer. The chitosan nano-particles were prepared by using the ionic gelation method. The characterizations of the nano-particles were determined by transmission electron microscopy. The cytotoxicity was detected by MTT assay, and the endocytosis, cell apoptosis and cell cycle were examined by flow cytometry. The protein level was analyzed with western blot. The dual luciferase reporter assay was performed to assess the interaction between p53 and the promoter of PRC1, and chromatin immune-precipitation was used to verify the binding between them. The FA-CS-DOX nano-particles were irregular and spherical particles around 30-40 nm, with uniform size and no adhesion. No significant difference was noted in doxorubicin release rate between CS-DOX and FA-CS-DOX. FA-CS-DOX nano-particles showed stronger cytotoxicity than CS-DOX. FA-CS-DOX nano-particles promoted the apoptosis and arrested cell cycle at G2/M phase, and they up-regulated p53. FA-CS-DOX nano-particles inhibited cell survival through p53/PRC1 pathway. Chitosan-coated doxorubicin nano-particles drug delivery system inhibits cell growth of liver cancer by promoting apoptosis and arresting cell cycle at G2/M phase through p53/PRC1 pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Experimental Analysis of Damping and Tribological Characteristics of Nano-CuO Particle Mixed Lubricant in Ball Bearings

Science.gov (United States)

Prakash, E.; Sivakumar, K.

2015-12-01

Experimental analysis of damping capacity and tribological characteristics of nano CuO added Servosystem 68 lubricant is attempted. CuO nano particles were synthesized by aqueous precipitation method and characterized. Prior to dispersion into lubricant, CuO nano particles were coated with 0.2 wt.% surfactant (Span-80) to stabilize the nano fluid. Tribological characteristics of particle added lubricant were tested in ASTM D 4172 four ball wear tester. Scanning electron microscopy test results of worn surfaces of nano CuO particle added lubricant were smoother than base lubricant. The particle added lubricant was applied in a new ball bearing and three defected ball bearings. When particle added lubricant was used, the ball defected bearing's vibration amplitude was reduced by 21.94% whereas it was 16.46% for new bearing and was ≤ 11% for other defected bearings. The formation of protection film of CuO over ball surface and regime of full film lubrication near the ball zone were observed to be reason for improved damping of vibrations.

Semi-flexible polymer engendered aggregation/dispersion of fullerene (C60) nano-particles: An atomistic investigation

Science.gov (United States)

Kumar, Sunil; Pattanayek, Sudip K.

2018-06-01

Semi flexible polymer chain has been modeled by choosing various values of persistent length (stiffness). As the polymer chain stiffness increases, the shape of polymer chain changes from globule to extended cigar to toroid like structure during cooling from a high temperature. The aggregation of fullerene nano-particles is found to depend on the morphology of polymer chain. To maximize, the number of polymer bead-nanoparticle contacts, all nano-particle have positioned inside the polymer globule. To minimize, the energy penalty, due to bending of the polymer chain, all nano-particle have positioned on the surface of the polymer's cigar and toroid morphology.

Coupling Fe{sup 0} nano particles with living and dead Azolla filicoloides to improve removal of methylene blue from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Rakhshaee, Roohan, E-mail: roohan_rakhshaee@guilan.ac.ir

2015-11-30

Highlights: • The novel living and dead bio–nano couples were prepared. • Living Azolla was more effective stabilizer for nano particles. • Increasing stabilization increased methylene blue (MB) adsorption. • The portion of Fe{sup 0} NPs had the main rule to determine kinetic model to adsorb MB. • It was studied the various factors rule on the living Azolla growth and MB removal. - Abstract: Fe{sup 0} nano particles (FNPs) were connected to the cell wall of the dead and living Azolla filicoloides as an aquatic fern, individually. FNPs mean size was decreased due to the stabilization, especially using the living one. It was compared the results of X-ray photoelectron spectroscopy (XPS), saturation magnetization (Ms), zeta potential (ZP) and thermal analysis (DSC and TGA) of the dead and living Azolla connected to FNPs, and also the findings of potentiometric titration (PT) of the cell wall's pectin of the dead and living Azolla. It was confirmed (by XRD and XPS) that Fe{sup 0} nano particles when were connected to the living Azolla did not produce Fe{sub 3}O{sub 4} due to oxidation unlike the bare FNPs and the connected form to the dead Azolla, by reason of the more stabilization (more surface protection) of nano iron particles after connecting to the living Azolla. To adsorb methylene blue by these agents at the optimum pre-treatment pH 10 and adsorption pH 8, the parameters of equilibrium sorption, rate constant of second-order sorption and activation energy were obtained as: living Azolla–FNPs > dead Azolla–FNPs > FNPs > dead Azolla, while, their thermodynamic parameters (ΔG°, ΔH° and ΔS°) had the reverse arrangement. It was also studied the various factors rule such as photoperiod and the presence of heavy metals on the living Azolla growth coupled with FNPs and its MB removal ability.

Noble Metal/Ceramic Composites in Flame Processes

DEFF Research Database (Denmark)

Schultz, Heiko; Madler, Lutz; Strobel, Reto

conditions influence the resulting noble metal particles size in those systems [1]. For every specific application the particle size and the metal/metal oxide interaction affect the performance of these nano-composite materials [2]. Recently, aerosol processes have been successfully used to produce platinum...

Nano tubular Transition Metal Oxide for Hydrogen Production

International Nuclear Information System (INIS)

Sreekantan, S.; San, E.P.; Kregvirat, W.; Wei, L.C.

2011-01-01

TiO 2 , transition metal oxide nano tubes were successfully grown by anodizing of titanium foil (Ti) in ethylene glycol electrolyte containing 5wt. % hydrogen peroxide and 5wt. % ammonium fluoride for 60 minutes at 60V. It was found such electrochemical condition resulted in the formation of nano tube with average diameter of 90nm and length of 6.6 μm. These samples were used to study the effect of W loading by RF sputtering on TiO 2 nano tubes. Amorphous TiO 2 nano tube substrate leads to enhance incorporation of W instead of anatase. Therefore for the entire study, W was sputtered on amorphous TiO 2 nano tube substrate. TiO 2 nano tube sputtered for 1 minute resulted in the formation of W-O-Ti while beyond this point (10 minutes); it accumulates to form a self independent structure of WO 3 on the surface of the nano tubes. TiO 2 nano tube sputtered for 1 minute at 150 W and annealed at 450 degree Celsius exhibited best photocurrent density (1.4 mA/ cm 2 ) with photo conversion efficiency of 2.5 %. The reason for such behavior is attributed to W 6+ ions allows for electron traps that suppress electron hole recombination and exploit the lower band gap of material to produce a water splitting process by increasing the charge separation and extending the energy range of photoexcitation for the system. (author)

Geometrical effects on the electron residence time in semiconductor nano-particles.

Science.gov (United States)

Koochi, Hakimeh; Ebrahimi, Fatemeh

2014-09-07

We have used random walk (RW) numerical simulations to investigate the influence of the geometry on the statistics of the electron residence time τ(r) in a trap-limited diffusion process through semiconductor nano-particles. This is an important parameter in coarse-grained modeling of charge carrier transport in nano-structured semiconductor films. The traps have been distributed randomly on the surface (r(2) model) or through the whole particle (r(3) model) with a specified density. The trap energies have been taken from an exponential distribution and the traps release time is assumed to be a stochastic variable. We have carried out (RW) simulations to study the effect of coordination number, the spatial arrangement of the neighbors and the size of nano-particles on the statistics of τ(r). It has been observed that by increasing the coordination number n, the average value of electron residence time, τ̅(r) rapidly decreases to an asymptotic value. For a fixed coordination number n, the electron's mean residence time does not depend on the neighbors' spatial arrangement. In other words, τ̅(r) is a porosity-dependence, local parameter which generally varies remarkably from site to site, unless we are dealing with highly ordered structures. We have also examined the effect of nano-particle size d on the statistical behavior of τ̅(r). Our simulations indicate that for volume distribution of traps, τ̅(r) scales as d(2). For a surface distribution of traps τ(r) increases almost linearly with d. This leads to the prediction of a linear dependence of the diffusion coefficient D on the particle size d in ordered structures or random structures above the critical concentration which is in accordance with experimental observations.

Zinc oxide nano-particles as sealer in endodontics and its sealing ability

Directory of Open Access Journals (Sweden)

Maryam Javidi

2014-01-01

Full Text Available Aims: The aim of this study was to evaluate the sealing ability of new experimental nano-ZOE-based sealer. Settings and Design: Three types of nano-ZOE-based sealer (calcined at different temperatures of 500, 600 and 700°C with two other commercially available sealers (AH26 and micro-sized zinc oxide eugenol sealer were used. Materials and Methods: Zinc oxide nano-particles were synthesized by a modified sol-gel method. The structure and morphology of the prepared powders were characterized using x-ray diffraction (XRD and transmission electron microscopy (TEM techniques. The instrumented canals of 60 single-rooted teeth were divided into five groups (n = 10, with the remaining ten used as controls. The canals were filled with gutta-percha using one of the materials mentioned above as sealer. After 3, 45 and 90 days, the samples were connected to a fluid filtration system. Statistical Analysis Used: The data were analyzed using Student′s t-test. Results: The XRD patterns and TEM images revealed that all the synthesized powders had hexagonal wurtzite structures with an average particle size of about 30-60 nm at different calcination temperatures. Microleakage in AH26 groups was significantly more than that in three groups of ZnO nano-particles at all the three evaluation intervals. Apical microleakage of ZnO micro-powders was significantly more than that of all the materials, but the sealing ability of ZnO nano-powder sealers did not differ significantly. Conclusion: The results of this study showed that the synthesized ZnO nano-powder sealers are suitable for use as a nano-sealer in root canal therapy to prevent leakage; however, further studies should be carried out to verify their safety.

The CHF enhancement on pool boiling using nano-fluids

International Nuclear Information System (INIS)

Chang, Won Joon; Jeong, Yong Hoon

2009-01-01

A increase of CHF was observed with nano-fluid. The addition of nano-particle helped to increase the wettability. This happens with the decrease in bubble diameter, breakup of bubbles and avoidance of bubble coalescence. CHF increase or decrease depends upon competition between high wettability and high instability. An optimum nano-fluid concentration is needed which must have high crystalline content. When the concentration reaches at a critical value, CHF will tend to a constant value. Deposition of nano-particles increasing the wettability and the rewetting are cause of CHF enhancement. It delay the growth of dry patch by increasing of wettability and lead to CHF enhancement. Now, we must define the wettability of nano-fluids. At case of nano-fluids using metallic particle, the explanation using contact angle using was reasonable. But, at case of nan-fluids using hydrophobic CNT, this explanation can't be acceptable. Moreover, at case of surfactant solution, contact angle was very low. But CHF enhancement was not great. So, wettability about nano-fluids must be defined anew for explanation of CHF enhancement. I suggest the extension of micro layer are acceptable concept for increasing wettability using nano-fluids

Boundary lubrication by nano-particles; Lubrification limite par les nanoparticules

Energy Technology Data Exchange (ETDEWEB)

Cizaire, L.

2003-09-15

The replacement of aggressive organic molecules by mineral particles which could reduce friction and wear has been the main idea of this research work. The aim is thus to reduce product concentration in lubricant and pollutant gas emission. Boundary lubrication regime is well suited for this type of study in particular for being discriminative in tested nano-particles efficacy. We are firstly being interested in an anti-wear additive. A physical and chemical study of dialysed over based calcium sulfonates by EFTEM, XPS and ToF-SIMS lead to describe nano-particles as calcium carbonate core, still amorphous by the residual presence of calcium hydroxide and surrounded by di-dodecyl-benzene sulfonate surfactant chains. Their anti-wear action has been investigated by coupling many tribo-meters with different contact geometry. Rubbing surfaces were protected by a thick tribo-film being on surfaces without any scratches. When additive is in contact area under high pressure and shearing, micellar structure is broken. Hydro-carbonated chains initially control friction by being broken up and then with increasing of contact severity, sulfonate chains are expulsed out of the tribo-film. Tribo-film growth corresponds then to agglomeration and crystallization of calcium carbonate core striped of detergent chains. We have shown then friction reduction capabilities of inorganic-fullerene (IF) MoS{sub 2} nano-particles. Lubricating power of MoS{sub 2} layers is as good whatever the layers number leading thinking that friction value is intrinsic character of compound nature. Fullerene nano-particles were described by HR-TEM as a concentric and closed multi-layered structure. Coupling of Raman, XRD and EXAFS have shown that MoS{sub 2} layers were well organised in hexagonal form with distortion in Mo-Mo bonds reaching 1% of initial length. Chemical stability of such structure, in particular in regard of oxidation, is very impressive. XPS, XANES and ToF-SIMS analyses have lead to

Synthesis of new nano Schiff base complexes: X-ray crystallography ...

African Journals Online (AJOL)

This study presents synthesis and characterization of new nano uranyl Schiff base complexes. Electrochemistry of these complexes showed a quasireversible redox reaction without any successive reactions. Furthermore, X-ray crystallography exhibited that beside the coordination of tetradentate Schiff base, one solvent ...

Effect of particle morphology of Ni on the mechanical behavior of AZ91E-Ni coated nano Al2O3 composites

Science.gov (United States)

Sameer Kumar, D.; Suman, K. N. S.; Poddar, Palash

2017-06-01

The properties of any composite always depend on the bonding between the matrix and reinforcement phases. One way of improving the wettability of reinforcement in a matrix is to apply a layer of coating on reinforcing particles. The present study aims at developing Ni coating on nano Al2O3 ceramic particles and dispersing them in AZ91E magnesium matrix material. The electroless plating method has been employed to coat the particles and semi solid stir casting technique was adopted to prepare the composites. Several weight fractions of dispersed phase are considered to analyze the behavior of the fabricated composites. Field emission scanning electron microscopy (FESEM) and x-ray diffraction analysis has been carried out to investigate the distribution of particles and phase characteristics of the proposed material. The physical and mechanical behavior of the material was examined through density measurements, hardness, elastic modulus, ductility and tensile strength calculations. The metal coating on reinforcement aids to promote metal-metal bonding interface reactions which result in improved properties of the composite. Tensile fractography was carried out under FESEM and presented.

Simultaneous decontamination of cross-polluted soils with heavy metals and PCBs using a nano-metallic Ca/CaO dispersion mixture.

Science.gov (United States)

Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Simion, Cristian

2014-01-01

In the present work, we investigated the use of nano-metallic calcium (Ca) and calcium oxide (CaO) dispersion mixture for the simultaneous remediation of contaminated soils with both heavy metals (As, Cd, Cr, and Pb) and polychlorinated biphenyls (PCBs). Regardless of soil moisture content, nano-metallic Ca/CaO dispersion mixture achieved about 95-99% of heavy metal immobilization by a simple grinding process. During the same treatment, reasonable PCB hydrodechlorination efficiencies were obtained (up to 97%), though higher hydrodechlorination efficiency by preliminary drying of soil was observed.

Synthesis and characterization of monoclinic KGd(WO4)2 particles for non-cubic transparent ceramics

Science.gov (United States)

Thangaraju, D.; Durairajan, A.; Balaji, D.; Moorthy Babu, S.

2013-02-01

Monoclinic KGd(WO4)2 (KGW) particles were synthesized using polymeric metal complex sol-gel synthesis method. The derived particles were made as colloidal suspension form for better rotation of particles to have optimum response for applied magnetic field. The KGW fine particle suspension was prepared using electrostatic repulsion by electrolyte polymer. Prepared suspension was kept at 2 T and particles were settled using electrophoretic sedimentation using pH adjustment. The derived sediment was dried at 100 °C and the properties were characterized using XRD.

Crystallization kinetics of Ga metallic nano-droplets under As flux

International Nuclear Information System (INIS)

Bietti, S; Somaschini, C; Sanguinetti, S

2013-01-01

We present an experimental investigation of the crystallization dynamics of Ga nano-droplets under As flux. The transformation of the metallic Ga contained in the droplets into a GaAs nano-island proceeds by increasing the size of a tiny ring of GaAs which is formed just after the Ga deposition at the rim of a droplet. The GaAs crystallization rate depends linearly on the liquid–solid interface area. The maximum growth rate is set by the As flux impinging on the droplet, thus showing an efficient As incorporation and transport despite the predicted low solubility of the As in metallic Ga at the crystallization temperatures. (paper)

Preparation and Characterization of Nano-structured Ceramic Powders Synthesized by Emulsion Combustion Method

International Nuclear Information System (INIS)

Takatori, Kazumasa; Tani, Takao; Watanabe, Naoyoshi; Kamiya, Nobuo

1999-01-01

The emulsion combustion method (ECM), a novel powder production process, was originally developed to synthesize nano-structured metal-oxide powders. Metal ions in the aqueous droplets were rapidly oxidized by the combustion of the surrounding flammable liquid. The ECM achieved a small reaction field and a short reaction period to fabricate the submicron-sized hollow ceramic particles with extremely thin wall and chemically homogeneous ceramic powder. Alumina, zirconia, zirconia-ceria solid solutions and barium titanate were synthesized by the ECM process. Alumina and zirconia powders were characterized to be metastable in crystalline phase and hollow structure. The wall thickness of alumina was about 10 nm. The zirconia-ceria powders were found to be single-phase solid solutions for a wide composition range. These powders were characterized as equiaxed-shape, submicron-sized chemically homogeneous materials. The powder formation mechanism was investigated through the synthesis of barium titanate powder with different metal sources

Internal Nano Voids in Yttria-Stabilised Zirconia (YSZ Powder

Directory of Open Access Journals (Sweden)

Chen Barad

2017-12-01

Full Text Available Porous yttria-stabilised zirconia ceramics have been gaining popularity throughout the years in various fields, such as energy, environment, medicine, etc. Although yttria-stabilised zirconia is a well-studied material, voided yttria-stabilised zirconia powder particles have not been demonstrated yet, and might play an important role in future technology developments. A sol-gel synthesis accompanied by a freeze-drying process is currently being proposed as a method of obtaining sponge-like nano morphology of embedded faceted voids inside yttria-stabilised zirconia particles. The results rely on a freeze-drying stage as an effective and simple method for generating nano-voided yttria-stabilised zirconia particles without the use of template-assisted additives.

Pt coating on flame-generated carbon particles

International Nuclear Information System (INIS)

Choi, In Dae; Lee, Dong Geun

2008-01-01

Carbon black, activated carbon and carbon nanotube have been used as supporting materials for precious metal catalysts used in fuel cell electrodes. One-step flame synthesis method is used to coat 2-5nm Pt dots on flame-generated carbon particles. By adjusting flame temperature, gas flow rates and resident time of particles in flame, we can obtain Pt/C nano catalyst-support composite particles. Additional injection of hydrogen gas facilitates pyrolysis of Pt precursor in flame. The size of as-incepted Pt dots increases along the flame due to longer resident time and sintering in high temperature flame. Surface coverage and dispersion of the Pt dots is varied at different sampling heights and confirmed by Transmission Electron Microscopy (TEM), Energy Dispersive Spectra (EDS) and X-Ray Diffraction (XRD). Crystallinity and surface bonding groups of carbon are investigated through X-ray Photoelectron Spectroscoy (XPS) and Raman spectroscopy

Characterization and Growth Mechanism of Nickel Nano wires Resulting from Reduction of Nickel Formate in Polyol Medium

International Nuclear Information System (INIS)

Logutenko, O.A.; Titkov, A.I.; Vorobyov, A.M.; Yukhin, Y.M.; Lyakhov, N.Z.

2016-01-01

Nickel linear nano structures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nano wires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nano crystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nano wires. The possible growth processes of the wire-shaped particles taking place at 110 and 130 degree are discussed. It was shown that, under certain synthesis conditions, nickel nano wires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

Ammonia Synthesis using Ti and Nb Nitride Nano-particles Prepared by Mesoporous Graphitic C3N4

KAUST Repository

Kumagai, Hiromu

2015-01-22

TiN and NbN nanoparticles were synthesized from mesoporous graphitic C3N4 (mpg-C3N4) as a reactive template and used as the catalyst for ammonia synthesis. The obtained TiN and NbN nanoparticles possess high surface areas of 299 and 275 m2 g-1, respectively, making them attractive in the use of catalysis and support. Although most of the TiN and NbN particles show no measurable activity for ammonia formation, the nanoparticles enabled an ammonia synthesis rate of 31 μmol h-1 g-cat-1 at 673 K and 0.1 MPa of synthesis gas (N2 + 3H2) for both TiN and NbN catalysts. It is evident that the formation of nanoparticles with high nitride surface area is essential for the materials to function as catalysts in ammonia synthesis. The addition of Fe to TiN enhanced the ammonia synthesis activity, whereas it had detrimental effects on the catalytic activity of NbN. The properties of these catalysts in ammonia synthesis are discussed.

Metal-carbon nanosystem IR-PVA/Fe-Co for catalysis in the Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Vasilev, A A; Dzidziguri, E L; Ivantsov, M I; Efimov, M N

2016-01-01

Metal-carbon nanosystems consisting of nanodimensional bimetallic particles of Fe- Co dispersed in a carbon matrix for the Fischer-Tropsch synthesis were studied. Prepared metal-carbon nanopowders samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It was shown formation of FeCo nanoparticles with body-centered cubic structures started at 400 °C. FeCo nanoparticles have spherical form, the mean size is 7 - 12 nm and uniform distribution in a carbon matrix. The metal-carbon nanosystem demonstrates a catalytic activity in the Fischer- Tropsch synthesis. The maximum yield of liquid hydrocabons C 5+ was 92 g/m 3 while the selectivity for the target product - 35%. (paper)

Electrochemical synthesis of metallic microstructures using etched ion tracks in nuclear track filters

International Nuclear Information System (INIS)

Sanjeev Kumar; Shyam Kumar; Rajesh Kumar; Chakravarti, K.

2004-01-01

Interest in nano/microstructures results from their numerous potential applications in various areas such as materials and biomedical sciences, electronics, optics, magnetism, energy storage and electrochemistry. Materials with micro/nanoscopic dimensions not only have potential technological applications in areas such as device technology and drug delivery, but also are of fundamental interest in that the properties of a material can change in this regime of transition between the bulk and molecular scales. Electrodeposition is a versatile technique combining low processing cost with ambient conditions that can be used to prepare metallic, polymeric and semiconducting microstructures. In the present work ion track membranes of Makrofol (KG) have been used as templates for synthesis of metallic microstructures using the technique of electrodeposition. (author)

Lead sulfide nano crystal preparation and characterization

International Nuclear Information System (INIS)

Sasani Ghamsari, M.

1999-01-01

Nanometer sized semiconductor particles have attracted much attention duo to their novel electronic and optical optical proportion, originating from quantum confinement. Pb S is one of the most important semiconductor material. In this project Pb S semiconductor nano crystal is synthesized in order to decrease particle size and study the modifications of their optical properties in relation to their size. The synthesis is carried out by using the technique of colloid chemistry. In this method we use lead nitrate extra pure and H2 S gas which is solved in the water. EDTA is used for controlling of particle size. A fast evolution of the optical absorption spectrum will be noticed following synthesis. Immediately after the synthesis reaction. The sample, exhibit a structured absorption spectrum with well defined excitonic peak in 240 nm theoretical relations is that shown this peak belong to 5 A particles. X-ray diffraction is used to establish the identity, phase and the size of these clusters

Synthesis and structural characterization of coaxial nano tubes intercalated of molybdenum disulfide with carbon

International Nuclear Information System (INIS)

Reza San German, C.M.

2005-01-01

In this work the study of some fundamental aspects in the growth of unidimensional systems of coaxial nano tubes from the mold method is approached. This method is an inclusion technique of a precursor reagent into oxide nano porous alumina film (mold), and later applying some processes of synthesis it is gotten to obtain the wished material. The synthesized structures are identified later because they take place by means of the initial formation of nano tubes of MoS 2 , enclosing to carbon nano tubes by the same method, with propylene flow which generates a graphitization process that 'copy' the mold through as it flows. Binary phase MoS 2 + C nano tubes were synthesized by propylene pyrolysis inside MoS 2 nano tubes prepared by template assisted technique. The large coaxial nano tubes constituted of graphite sheets inserted between the MoS 2 layers forming the outer part, and coaxial multi wall carbon nano tubes (MWCNT) intercalated with MoS 2 inside. High resolution electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), high angle annular dark field (HAADF), gatan image filter (GIF), nano beam electron diffraction patterns (NBEDP), along with molecular dynamics simulation and quantum mechanical calculations were used to characterize the samples. The one-dimensional structures exhibit diverse morphologies such as long straight and twisted nano tubes with several structural irregularities. The inter-planar spacing between MoS 2 layers was found to increase from 6.3 to 7.4 A due to intercalation with carbon. Simulated HREM images revealed the presence of these twisted nano structures, with mechanical stretch into intercalate carbon between MoS 2 layers. Our results open up the possibility of using MoS 2 nano tubes as templates for the synthesis of new one- dimensional binary phase systems. (Author)

μ-reactor measurements of catalytic activity of mass selected nano-particles

DEFF Research Database (Denmark)

Riedel, Jakob Nordheim

The work of this thesis revolves around catalytic activity measurements of nano-particles tested using a μ-reactor platform, developed and produced at DTU, in a collaboration between CINF and Nanotech. The thesis contains the results from two separate research projects; both utilising μ-reactors ......The work of this thesis revolves around catalytic activity measurements of nano-particles tested using a μ-reactor platform, developed and produced at DTU, in a collaboration between CINF and Nanotech. The thesis contains the results from two separate research projects; both utilising μ......-reactors in combination with surface science techniques and computer simulations. The first project described is a study of hydrogen dissociation on mono-disperse platinum clusters. The second project studies methanation from carbon monoxide and hydrogen on nano-particles of nickel-iron alloys. The second study is a work...... in progress, and the corresponding chapter aims to summarise the results so far. Other projects are not included in the thesis because they are inconclusive or dead ends. Hydrogen dissociation was studied by the H2/D2 exchange reaction on SiO2-supported mono-disperse platinum clusters in a -reactor...

A Facile Method for Separating and Enriching Nano and Submicron Particles from Titanium Dioxide Found in Food and Pharmaceutical Products.

Science.gov (United States)

Faust, James J; Doudrick, Kyle; Yang, Yu; Capco, David G; Westerhoff, Paul

2016-01-01

Recent studies indicate the presence of nano-scale titanium dioxide (TiO2) as an additive in human foodstuffs, but a practical protocol to isolate and separate nano-fractions from soluble foodstuffs as a source of material remains elusive. As such, we developed a method for separating the nano and submicron fractions found in commercial-grade TiO2 (E171) and E171 extracted from soluble foodstuffs and pharmaceutical products (e.g., chewing gum, pain reliever, and allergy medicine). Primary particle analysis of commercial-grade E171 indicated that 54% of particles were nano-sized (i.e., E171 and E171 isolated from foodstuffs and pharmaceuticals was accomplished using rate-zonal centrifugation. Commercial-grade E171 was separated into nano- and submicron-enriched fractions consisting of a nano:submicron fraction of approximately 0.45:1 and 3.2:1, respectively. E171 extracted from gum had nano:submicron fractions of 1.4:1 and 0.19:1 for nano- and submicron-enriched, respectively. We show a difference in particle adhesion to the cell surface, which was found to be dependent on particle size and epithelial orientation. Finally, we provide evidence that E171 particles are not immediately cytotoxic to the Caco-2 human intestinal epithelium model. These data suggest that this separation method is appropriate for studies interested in isolating the nano-sized particle fraction taken directly from consumer products, in order to study separately the effects of nano and submicron particles.

Effects of annealing temperature in a metal alloy nano-dot memory

International Nuclear Information System (INIS)

Lee, Jung Min; Lee, Gae Hun; Song, Yun Heub; Bea, Ji Cheol; Tanaka, Tetsu

2011-01-01

The annealing temperature dependence of the capacitance-voltage (C-V) characteristic has been studied in a metal-oxide semiconductor structure containing FePt nano-dots. Several in-situ annealing temperatures from 400 to ∼700 .deg. C in a high vacuum ambience (under 1 x 10 -5 Pa) were evaluated in view of the cell's characteristics and its reliability. Here, we demonstrate that the annealing temperature is significant for memory performance in an alloy metal nano-dot structure. A higher in-situ temperature provides better retention and a more reliable memory window. In the sample with an in-situ annealing condition of 700 .deg. C for 30 min, a memory window of 9.2 V at the initial stage was obtained, and a memory window of 6.2 V after 10 years was estimated, which is reliable for a non-volatile memory. From these results, the annealing condition for an alloy metal nano-dot memory is one of the critical parameters for the memory characteristics, and should be optimized for better memory performance.

Spatially confined synthesis of SiOx nano-rod with size-controlled Si quantum dots in nano-porous anodic aluminum oxide membrane.

Science.gov (United States)

Pai, Yi-Hao; Lin, Gong-Ru

2011-01-17

By depositing Si-rich SiOx nano-rod in nano-porous anodic aluminum oxide (AAO) membrane using PECVD, the spatially confined synthesis of Si quantum-dots (Si-QDs) with ultra-bright photoluminescence spectra are demonstrated after low-temperature annealing. Spatially confined SiOx nano-rod in nano-porous AAO membrane greatly increases the density of nucleated positions for Si-QD precursors, which essentially impedes the route of thermally diffused Si atoms and confines the degree of atomic self-aggregation. The diffusion controlled growth mechanism is employed to determine the activation energy of 6.284 kJ mole(-1) and diffusion length of 2.84 nm for SiO1.5 nano-rod in nano-porous AAO membrane. HRTEM results verify that the reduced geometric dimension of the SiOx host matrix effectively constrain the buried Si-QD size at even lower annealing temperature. The spatially confined synthesis of Si-QD essentially contributes the intense PL with its spectral linewidth shrinking from 210 to 140 nm and its peak intensity enhancing by two orders of magnitude, corresponding to the reduction on both the average Si-QD size and its standard deviation from 2.6 to 2.0 nm and from 25% to 12.5%, respectively. The red-shifted PL wavelength of the Si-QD reveals an inverse exponential trend with increasing temperature of annealing, which is in good agree with the Si-QD size simulation via the atomic diffusion theory.

In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

OpenAIRE

Farzin Heravi; Mohammad Ramezani; Maryam Poosti; Mohsen Hosseini; Arezoo Shajiei; Farzaneh Ahrari

2013-01-01

Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2) nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco’s Modified Eagle’s Medium (DMEM). The extrac...

6. international conference on Nano-technology in Carbon: from synthesis to applications of nano-structured carbon and related materials

International Nuclear Information System (INIS)

2004-01-01

This is the sixth international conference sponsored this year by the French Carbon Group (GFEC), the European Research Group on Nano-tubes GDRE 'Nano-E', in collaboration with the British Carbon Group and the 'Institut des Materiaux Jean Rouxel' (local organizer). The aim of this conference is to promote carbon science in the nano-scale as, for example, nano-structured carbons, nano-tubes, nano-wires, fullerenes, etc. This conference is designed to introduce those with an interest in materials to current research in nano-technology and to bring together research scientists working in various disciplines in the broad area of nano-structured carbons, nano-tubes and fullerene-related nano-structures. Elemental carbon is the simplest exemplar of this nano-technology based on covalent bonding, however other systems (for example containing hetero-atoms) are becoming important from a research point of view, and provide alternative nano-materials with unique properties opening a broad field of applications. Nano-technology requires an understanding of these materials on a structural and textural point of view and this will be the central theme. This year the conference will feature sessions on: S1. Control and synthesis of nano-materials 1.1 Nano-structured carbons: pyrolysis of polymers, activation, templates,... 1.2 Nano-tubes: Catalytic method, HiPCO, graphite vaporization, electrolysis,... 1.3 Fullerenes S2. Chemistry of carbon nano-materials 2.1 Purification of carbon nano-tubes 2.2 Functionalization - Self-assembling S3. Structural characterization S4. Theory and modelling S5. Relationship between structure and properties S6. Applications Water and air purification, Gas and energy storage, Composite materials, Field emission, Nano-electronics, Biotechnology,... S7. Environmental impact. Only one paper concerning carbon under irradiation has been added to the INIS database. (authors)

Distributed Bragg grating frequency control in metallic nano lasers

NARCIS (Netherlands)

Marell, M.J.H.; Hill, M.T.

2010-01-01

We show that Bragg gratings can be readily incorporated into metallic nano-lasers which exploit waveguides with semiconductor cores, via modulation of the waveguide width. This provides a simple way to implement laser wavelength control.

Effects of gamma irradiation and silver nano particles on microbiological characteristics of saffron, using hurdle technology.

Science.gov (United States)

Hamid Sales, E; Motamedi Sedeh, F; Rajabifar, S

2012-03-01

Saffron, a plant from the Iridaceae family, is the world's most expensive spice. Gamma irradiation and silver nano particles whose uses are gradually increasing worldwide, have positive effects on preventing decay by sterilizing the microorganisms and by improving the safety without compromising the nutritional properties and sensory quality of the foods. In the present study combination effects of gamma irradiation and silver nano particles packaging on the microbial contamination of saffron were considered during storage. A combination of hurdles can ensure stability and microbial safety of foods. For this purpose, saffron samples were packaged by Poly Ethylene films that posses up to 300 ppm nano silver particles as antimicrobial agents and then irradiated in cobalt-60 irradiator (gamma cell PX30, dose rate 0.55 Gry/Sec) to 0, 1, 2,3 and 4 kGy at room temperature. The antimicrobial activities against Total Aerobic Mesophilic Bacteria, Entrobacteriace, Escherichia Coli and Clostridium Perfringines were higher in the irradiated samples, demonstrating the inhibition zone for their growth. Irradiation of the saffron samples packaged by Poly Ethylene films with nano silver particles showed the best results for decreasing microbial contamination at 2 kGy and for Poly Ethylene films without silver nano particles; it was 4 kGy.

Optimization of mechanical performance of oxidative nano-particle electrode nitrile butadiene rubber conducting polymer actuator.

Science.gov (United States)

Kim, Baek-Chul; Park, S J; Cho, M S; Lee, Y; Nam, J D; Choi, H R; Koo, J C

2009-12-01

Present work delivers a systematical evaluation of actuation efficiency of a nano-particle electrode conducting polymer actuator fabricated based on Nitrile Butadiene Rubber (NBR). Attempts are made for maximizing mechanical functionality of the nano-particle electrode conducting polymer actuator that can be driven in the air. As the conducting polymer polypyrrole of the actuator is to be fabricated through a chemical oxidation polymerization process that may impose certain limitations on both electrical and mechanical functionality of the actuator, a coordinated study for optimization process of the actuator is necessary for maximizing its performance. In this article actuation behaviors of the nano-particle electrode polypyrrole conducting polymer is studied and an optimization process for the mechanical performance maximization is performed.

The fabrication and single electron transport of Au nano-particles placed between Nb nanogap electrodes

International Nuclear Information System (INIS)

Nishino, T; Negishi, R; Ishibashi, K; Kawao, M; Nagata, T; Ozawa, H

2010-01-01

We have fabricated Nb nanogap electrodes using a combination of molecular lithography and electron beam lithography. Au nano-particles with anchor molecules were placed in the gap, the width of which could be controlled on a molecular scale (∼2 nm). Three different anchor molecules which connect the Au nano-particles and the electrodes were tested to investigate their contact resistance, and a local gate was fabricated underneath the Au nano-particles. The electrical transport measurements at liquid helium temperatures indicated single electron transistor (SET) characteristics with a charging energy of about ∼ 5 meV, and a clear indication of the effect of superconducting electrodes was not observed, possibly due to the large tunnel resistance.

Synthesis and characterization of poly[1-(N,N-bis-carboxymethyl)amino-3-allylglycerol-co-dimethylacrylamide] grafted to magnetic nano-particles for extraction and determination of letrozole in biological and pharmaceutical samples.

Science.gov (United States)

Ahmad Panahi, Homayon; Soltani, Elham Reza; Moniri, Elham; Tamadon, Atefeh

2013-12-15

In this paper, a new method is reported for the surface grafting of poly[1-(N,N-bis-carboxymethyl)amino-3-allylglycerol-co-dimethylacrylamide] onto magnetic nano-particles modified by 3-mercaptopropyltrimethoxysilane. The grafted nano-sorbent was characterized by Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, and scanning electron microscopy. Agglomerated nano-particles with multi-pores were used for extraction and determination of trace letrozole in human biological fluids and pharmaceutical samples. The profile of the letrozole uptake by the magnetic nano-sorbent reflected good accessibility of the active sites in the grafted polymer. Scatchard analysis revealed that the sorption capacity of the functionalized nano-sorbent was 6.27 µmol g(-1) at an optimum pH of 4. The equilibrium adsorption data of letrozole by grafted magnetic nano-sorbent were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models. Conformation of the experimental data in the Langmuir isotherm model indicated the homogeneous binding site of functional polymer-grafted magnetic nano-sorbent surface. Nearly 89% of letrozole was released in simulated gastric fluid, pH 1.2, in 2h and 79% in simulated intestinal fluid, pH 7.4, in 30 h. These results show the utility of the letrozole loaded- polymer grafted magnetite nano-particles for enteric drug delivery. © 2013 Elsevier B.V. All rights reserved.

Deposition of toxic metal particles on rough nanofiltration membranes

International Nuclear Information System (INIS)

Agboola, Oluranti; Maree, Jannie; Mbaya, Richard; Zvinowanda, Caliphs Musa; Molelekwa, Gomotsegang Fred; Jullok, Nora; Bruggen, Bart Van der; Volodine, Alexander; Haesendonck, Chris Van

2014-01-01

Two nanofiltration (NF90 and Nano-Pro-3012) membranes were investigated for their capacity to remove metal ions. This study presents the effect of membrane roughness on the removal of toxic metal ions during dead end membrane filtration. Atomic force microscopy, scanning electron microscopy, WSXM software and ImageJ were used to characterize the roughness of the membranes. Gradual decrease in filtration permeate flux was observed as foulants accumulated at the interface of the membranes; filtration permeate flux varied from 20 L/m 2 /h to 14 L/m 2 /h and 11 L/ m 2 /h to 6 L/m 2 /h for NF90 and Nano-Pro-3012, respectively. NF90 membrane was more prone to fouling than the Nano-Pro-3012 membrane: the percentage flux reduction was higher for NF90 (3.6%) than Nano-Pro-3012 (0.98%). The bearing ratio of the fouled NF90 exhibited a high peak of 7.09 nm than the fouled Nano-Pro-3012 with the peak of 6.8 nm

Deposition of toxic metal particles on rough nanofiltration membranes

Energy Technology Data Exchange (ETDEWEB)

Agboola, Oluranti; Maree, Jannie; Mbaya, Richard; Zvinowanda, Caliphs Musa [Tshwane University of Technology, Pretoria (South Africa); Molelekwa, Gomotsegang Fred; Jullok, Nora; Bruggen, Bart Van der; Volodine, Alexander; Haesendonck, Chris Van [KU Leuven, Heverlee (Belgium)

2014-08-15

Two nanofiltration (NF90 and Nano-Pro-3012) membranes were investigated for their capacity to remove metal ions. This study presents the effect of membrane roughness on the removal of toxic metal ions during dead end membrane filtration. Atomic force microscopy, scanning electron microscopy, WSXM software and ImageJ were used to characterize the roughness of the membranes. Gradual decrease in filtration permeate flux was observed as foulants accumulated at the interface of the membranes; filtration permeate flux varied from 20 L/m{sup 2}/h to 14 L/m{sup 2}/h and 11 L/ m{sup 2}/h to 6 L/m{sup 2}/h for NF90 and Nano-Pro-3012, respectively. NF90 membrane was more prone to fouling than the Nano-Pro-3012 membrane: the percentage flux reduction was higher for NF90 (3.6%) than Nano-Pro-3012 (0.98%). The bearing ratio of the fouled NF90 exhibited a high peak of 7.09 nm than the fouled Nano-Pro-3012 with the peak of 6.8 nm.

Study on treatment of radioactive liquid waste from uranium ore processing by the use of nano Fe_3O_4 KT particles

International Nuclear Information System (INIS)

Vuong Huu Anh; Nguyen Ba Tien; Doan Thi Thu Hien; Luu Cao Nguyen; Nguyen Van Chinh

2015-01-01

Nano Fe_3O_4 KT was produced from the Military Institute of Science and Technology were used to adsorbed heavy metal elements in liquid waste. In this report, the nano Fe_3O_4 KT particles sized 80-100 nm and specific surface area was 50-70 m"2/g was applied to study the adsorption of radioactive elements in the liquid waste of uranium ores processing. The effective parameters on adsorption process included temperature, stirring rate, stirring time, the pH value of the solution, the initial concentration of uranium in solution. The results showed the maximum adsorption capacity of the nano Fe_3O_4 KT was 53.5 mg/g with conditions such as room temperature, stirring speed 120 rounds/minute, the pH value of solution was 8, stirring time about 2 hours (Uranium/materials). From the results obtained, nano Fe_3O_4 KT tested to treatment liquid waste of uranium ore processing after preliminary precipitation removed almost heavy metals and a part of radioactive elements. The results were analyzed on the ICP-MS and α, β total counting, instrument. The solution concentration after treatment was suitable for Vietnam discharge standards into environment (QCVN 40:2011 on Industrial wastewater). (author)

Support vector machine to predict diesel engine performance and emission parameters fueled with nano-particles additive to diesel fuel

Science.gov (United States)

Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

2015-12-01

This paper studies the use of adaptive Support Vector Machine (SVM) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For SVM modelling, different values for radial basis function (RBF) kernel width and penalty parameters (C) were considered and the optimum values were then found. The results demonstrate that SVM is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve complete combustion of the fuel and reduce the exhaust emissions significantly.

Adaptive neuro-fuzzy inference system (ANFIS) to predict CI engine parameters fueled with nano-particles additive to diesel fuel

Science.gov (United States)

Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

2015-12-01

This paper studies the use of adaptive neuro-fuzzy inference system (ANFIS) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For ANFIS modelling, Gaussian curve membership function (gaussmf) and 200 training epochs (iteration) were found to be optimum choices for training process. The results demonstrate that ANFIS is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve combustion of the fuel and reduce the exhaust emissions significantly.

Reactivity of palladium nano-particles supported in hydrogenation: role of particles surface density; Reactivite des nanoparticules de palladium supportees en hydrogenation: role de la densite surfacique de particules

Energy Technology Data Exchange (ETDEWEB)

Benkhaled, M.

2004-10-01

The objective of this work is to investigate the influence of the particle surface density on the hydrogenation of polyunsaturated compounds (buta-1,3-diene, ortho-xylene). Highly dispersed Pd/Al{sub 2}O{sub 3} ({gamma} and {delta}-Al{sub 2}O{sub 3}) catalysts were prepared from Pd(nitrite) complexes (size < 7 angstrom, controlled by TEM, HAADF, EXAFS and CO chemisorption). Increasing the particle surface density from 2240 to 12880 particles/{mu}m{sup 2} leads to a modification of the electronic properties as evidenced by CO-FTIR, XPS and XANES. By contrast, the comparison of the supports at iso-density showed no significant difference of the physico-chemical properties of the supported metal particles. In parallel, the catalytic performances in hydrogenation of butadiene and butenes are very sensitive both to the nature of the support for the same density and to the surface density for the same support. It was shown that the reactions of hydrogenation could be controlled at the same time by the electronic properties of the metal nano-particles but also by the phenomenon of hydrogen diffusion around the particles on a zone of support. In this case, the support can play the part of hydrogen tank. (author)

Development of functional nano-particle layer for highly efficient OLED

Science.gov (United States)

Lee, Jae-Hyun; Kim, Min-Hoi; Choi, Haechul; Choi, Yoonseuk

2015-12-01

Organic light emitting diodes (OLEDs) are now widely commercialized in market due to many advantages such as possibility of making thin or flexible devices. Nevertheless there are still several things to obtain the high quality flexible OLEDs, one of the most important issues is the light extraction of the device. It is known that OLEDs have the typical light loss such as the waveguide loss, plasmon absorption loss and internal total reflection. In this paper, we demonstrate the one-step processed light scattering films with aluminum oxide nano-particles and polystyrene matrix composite to achieve highly efficient OLEDs. Optical characteristics and surface roughness of light scattering film was optimized by changing the mixing concentration of Al2O3 nano-particles and investigated with the atomic force microscopy and hazemeter, respectively.

Water-soluble ions in nano/ultrafine/fine/coarse particles collected near a busy road and at a rural site

International Nuclear Information System (INIS)

Lin, C.-C.; Chen, S.-J.; Huang, K.-L.; Lee, W.-J.; Lin, W.-Y.; Liao, C.-J.; Chaung, H.-C.; Chiu, C.-H.

2007-01-01

This study investigated water-soluble ions in the sized particles (particularly nano (PM 0.01-0.056 )/ultrafine (PM 0.01-0.1 )) collected using MOUDI and Nano-MOUDI samplers near a busy road site and at a rural site. The analytical results demonstrate that nano and coarse particles exhibited the highest (16.3%) and lowest (8.37%) nitrate mass ratios, respectively. The mass ratio of NO 3 - was higher than that of SO 4 2- in all the sized particles at the traffic site. The secondary aerosols all displayed trimodal distributions. The aerosols in ultrafine particles collected at the roadside site exhibited Aitken mode distributions indicating they were of local origin. This finding was not observed for those ultrafine particles collected at the rural site. The mass median diameters (MMDs) of the nano, ultrafine, and fine particles were smaller at the traffic site than at the rural site, possibly related to the contribution of mobile engine emissions. - NO 3 - > SO 4 2- in mass ratio, different from common observations in rural areas, was found in (particularly the nano) traffic-associated particles

Individual metal-bearing particles in a regional haze caused by firecracker and firework emissions

Energy Technology Data Exchange (ETDEWEB)

Li, Weijun [Environment Research Institute, Shandong University, Jinan, Shandong 250100 (China); State Key of Laboratory of Atmospheric Boundary Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029 (China); Shi, Zongbo [School of Geography, Earth and Environmental Sciences, University of Birmingham (United Kingdom); Yan, Chao; Yang, Lingxiao; Dong, Can; Wang, Wenxing [Environment Research Institute, Shandong University, Jinan, Shandong 250100 (China)

2013-01-15

Intensive firecracker/firework displays during Chinese New Year (CNY) release fine particles and gaseous pollutants into the atmosphere, which may lead to serious air pollution. We monitored ambient PM{sub 2.5} and black carbon (BC) concentrations at a regional background site in the Yellow River Delta region during the CNY in 2011. Our monitoring data and MOUDI images showed that there was a haze event during the CNY. Daily average PM{sub 2.5} concentration reached 183 μg m{sup −3} during the CNY, which was six times higher than that before and after the CNY. Similarly, the black carbon (BC) concentrations were elevated during the CNY. In order to confirm whether the firecracker/firework related emission is the main source of the haze particles, we further analyzed the morphology and chemical composition of individual airborne particles collected before, during and after the CNY by using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM/EDS). We found that sulfate and organic-rich particles were dominant in the atmosphere before and after the CNY. In contrast, K-rich sulfates and other metal (e.g., Ba-rich, Al-rich, Mg-rich, and Fe-rich) particles were much more abundant than ammoniated sulfate particles during the CNY. These data suggest that it was the aerosol particles from the firecracker/firework emissions that induced the regional haze episode during the CNY. In individual organic and K-rich particles, we often found more than two types of nano-metal particles. These metal-bearing particles also contained abundant S but not Cl. In contrast, fresh metal-bearing particles from firecrackers generated in the laboratory contained abundant Cl with minor amounts of S. This indicates that the firecracker/firework emissions during the CNY significantly changed the atmospheric transformation pathway of SO{sub 2} to sulfate. - Highlights: ► TEM was used to observe the aged individual particles from firecrackers

Individual metal-bearing particles in a regional haze caused by firecracker and firework emissions

International Nuclear Information System (INIS)

Li, Weijun; Shi, Zongbo; Yan, Chao; Yang, Lingxiao; Dong, Can; Wang, Wenxing

2013-01-01

Intensive firecracker/firework displays during Chinese New Year (CNY) release fine particles and gaseous pollutants into the atmosphere, which may lead to serious air pollution. We monitored ambient PM 2.5 and black carbon (BC) concentrations at a regional background site in the Yellow River Delta region during the CNY in 2011. Our monitoring data and MOUDI images showed that there was a haze event during the CNY. Daily average PM 2.5 concentration reached 183 μg m −3 during the CNY, which was six times higher than that before and after the CNY. Similarly, the black carbon (BC) concentrations were elevated during the CNY. In order to confirm whether the firecracker/firework related emission is the main source of the haze particles, we further analyzed the morphology and chemical composition of individual airborne particles collected before, during and after the CNY by using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM/EDS). We found that sulfate and organic-rich particles were dominant in the atmosphere before and after the CNY. In contrast, K-rich sulfates and other metal (e.g., Ba-rich, Al-rich, Mg-rich, and Fe-rich) particles were much more abundant than ammoniated sulfate particles during the CNY. These data suggest that it was the aerosol particles from the firecracker/firework emissions that induced the regional haze episode during the CNY. In individual organic and K-rich particles, we often found more than two types of nano-metal particles. These metal-bearing particles also contained abundant S but not Cl. In contrast, fresh metal-bearing particles from firecrackers generated in the laboratory contained abundant Cl with minor amounts of S. This indicates that the firecracker/firework emissions during the CNY significantly changed the atmospheric transformation pathway of SO 2 to sulfate. - Highlights: ► TEM was used to observe the aged individual particles from firecrackers/fireworks during the Chinese New

Minimum ignition energy of nano and micro Ti powder in the presence of inert nano TiO₂ powder.

Science.gov (United States)

Chunmiao, Yuan; Amyotte, Paul R; Hossain, Md Nur; Li, Chang

2014-06-15

The inerting effect of nano-sized TiO2 powder on ignition sensitivity of nano and micro Ti powders was investigated with a Mike 3 apparatus. "A little is not good enough" is also suitable for micro Ti powders mixed with nano-sized solid inertants. MIE of the mixtures did not significantly increase until the TiO2 percentage exceeded 50%. Nano-sized TiO2 powders were ineffective as an inertant when mixed with nano Ti powders, especially at higher dust loadings. Even with 90% nano TiO2 powder, mixtures still showed high ignition sensitivity because the statistic energy was as low as 2.1 mJ. Layer fires induced by ignited but unburned metal particles may occur for micro Ti powders mixed with nano TiO2 powders following a low level dust explosion. Such layer fires could lead to a violent dust explosion after a second dispersion. Thus, additional attention is needed to prevent metallic layer fires even where electric spark potential is low. In the case of nano Ti powder, no layer fires were observed because of less flammable material involved in the mixtures investigated, and faster flame propagation in nanoparticle clouds. Copyright © 2014 Elsevier B.V. All rights reserved.

Emerging boom in nano magnetic particle incorporated high-Tc superconducting materials and technologies - A South African perspective

CSIR Research Space (South Africa)

Srinivasu, VV

2009-01-01

Full Text Available With a strategy to establish and embrace the emerging nano particle incorporated superconductivity technology (based on the HTS materials and nano magnetic particles) in South Africa, the author has initiated the following research activity in South...

Effects of Alumina Nano Metal Oxide Blended Palm Stearin Methyl Ester Bio-Diesel on Direct Injection Diesel Engine Performance and Emissions

Science.gov (United States)

Krishna, K.; Kumar, B. Sudheer Prem; Reddy, K. Vijaya Kumar; Charan Kumar, S.; Kumar, K. Ravi

2017-08-01

The Present Investigation was carried out to study the effect of Alumina Metal Oxide (Al2O3) Nano Particles as additive for Palm Stearin Methyl Ester Biodiesel (B 100) and their blends as an alternate fuel in four stroke single cylinder water cooled, direct injection diesel engine. Alumina Nano Particles has high calorific value and relatively high thermal conductivity (30-1 W m K-1) compare to diesel, which helps to promote more combustion in engines due to their higher thermal efficiency. In the experimentation Al2O3 were doped in various proportions with the Palm Stearin Methyl Ester Biodiesel (B-100) using an ultrasonicator and a homogenizer with cetyl trimethyl ammonium bromide (CTAB) as the cationic surfactant. The test were performed on a Kirsloskar DI diesel engine at constant speed of 1500 rpm using different Nano Biodiesel Fuel blends (psme+50 ppm, psme+150 ppm, and psme+200 ppm) and results were compared with those of neat conventional diesel and Palm Stearin Methyl Ester Bio diesel. It was observed that for Nano Biodiesel Fuel blend (psme+50ppm) there is an significant reduction in carbon monoxide (CO) emissions and Nox emissions compared to diesel and the brake thermal efficiency for (psme+50ppm) was almost same as diesel.

Nano-architecture of metal-organic frameworks

Science.gov (United States)

Milichko, Valentin A.; Zalogina, Anastasiia; Mingabudinova, Leila R.; Vinogradov, Alexander V.; Ubyivovk, Evgeniy; Krasilin, Andrei A.; Mukhin, Ivan; Zuev, Dmitry A.; Makarov, Sergey V.; Pidko, Evgeny A.

2017-09-01

Change the shape and size of materials supports new functionalities never found in the sources. This strategy has been recently applied for porous crystalline materials - metal-organic frameworks (MOFs) to create hollow nanoscale structures or mesostructures with improved functional properties. However, such structures are characterized by amorphous state or polycrystallinity which limits their applicability. Here we follow this strategy to create such nano- and mesostructures with perfect crystallinity and new photonics functionalities by laser or focused ion beam fabrication.

Preparation of nano-hydroxyapatite particles with different morphology and their response to highly malignant melanoma cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Li Bo [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China); Guo Bo [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China); West China Eye Center of Huaxi Hospital, Sichuan University, Chengdu 610064 (China); Fan Hongsong [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China)], E-mail: leewave@126.com; Zhang Xingdong [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China)

2008-11-15

To investigate the effects of nano-hydroxyapatite (HA) particles with different morphology on highly malignant melanoma cells, three kinds of HA particles with different morphology were synthesized and co-cultured with highly malignant melanoma cells using phosphate-buffered saline (PBS) as control. A precipitation method with or without citric acid addition as surfactant was used to produce rod-like hydroxyapatite (HA) particles with nano- and micron size, respectively, and a novel oil-in-water emulsion method was employed to prepare ellipse-like nano-HA particles. Particle morphology and size distribution of the as prepared HA powders were characterized by transmission electron microscope (TEM) and dynamic light scattering technique. The nano- and micron HA particles with different morphology were co-cultured with highly malignant melanoma cells. Immunofluorescence analysis and MTT assay were employed to evaluate morphological change of nucleolus and proliferation of tumour cells, respectively. To compare the effects of HA particles on cell response, the PBS without HA particles was used as control. The experiment results indicated that particle nanoscale effect rather than particle morphology of HA was more effective for the inhibition on highly malignant melanoma cells proliferation.

Experimental study of improved rheology and lubricity of drilling fluids enhanced with nano-particles

Science.gov (United States)

Bég, O. Anwar; Espinoza, D. E. Sanchez; Kadir, Ali; Shamshuddin, MD.; Sohail, Ayesha

2018-04-01

An experimental study of the rheology and lubricity properties of a drilling fluid is reported, motivated by applications in highly deviated and extended reach wells. Recent developments in nanofluids have identified that the judicious injection of nano-particles into working drilling fluids may resolve a number of issues including borehole instability, lost circulation, torque and drag, pipe sticking problems, bit balling and reduction in drilling speed. The aim of this article is, therefore, to evaluate the rheological characteristics and lubricity of different nano-particles in water-based mud, with the potential to reduce costs via a decrease in drag and torque during the construction of highly deviated and ERD wells. Extensive results are presented for percentage in torque variation and coefficient of friction before and after aging. Rheology is evaluated via apparent viscosity, plastic viscosity and gel strength variation before and after aging for water-based muds (WBM). Results are included for silica and titanium nano-particles at different concentrations. These properties were measured before and after aging the mud samples at 80 °C during 16 h at static conditions. The best performance was shown with titanium nano-particles at a concentration of 0.60% (w/w) before aging.

Effect of silver nano particles on flexural strength of acrylic resins.

Science.gov (United States)

Sodagar, Ahmad; Kassaee, Mohammad Zaman; Akhavan, Azam; Javadi, Negar; Arab, Sepideh; Kharazifard, Mohammad Javad

2012-04-01

Poly(methyl methacrylate), PMMA, is widely used for fabrication of removable orthodontic appliances. Silver nano particles (AgNps) have been added to PMMA because of their antimicrobial properties. The aim of this study is to investigate the effect of AgNps on the flexural strength of PMMA. Acrylic liquid containing 0.05% and 0.2% AgNps was prepared for two kinds of acrylic resins: Rapid Repair &Selecta Plus. Two groups without AgNps were used as control groups. For each one, flexural strength was investigated via Three Point Bending method for the 15 acrylic blocks. Two-way ANOVA, one way ANOVA and Tukey tests were used for statistical analysis. Rapid Repair without AgNps showed the highest flexural strength. Addition of 0.05% AgNps to Rapid Repair, significantly decreased its flexural strength while, continuing the addition up to 0.2% increased it nearly up to its primary level. In contrast, addition of AgNps to Selecta Plus increased its flexural strength but addition of 0.05% nano particles was more effective than 0.2%. The effect of AgNps on flexural strength of PMMA depends on several factors including the type of acrylics and the concentrations of nano particles. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Preparation and characterization of squeeze cast-Al–Si piston alloy reinforced by Ni and nano-Al2O3 particles

Directory of Open Access Journals (Sweden)

Hashem F. El-Labban

2016-07-01

Full Text Available Al–Si base composites reinforced with different mixtures of Ni and nano-Al2O3 particles have been fabricated by squeeze casting and their metallurgical and mechanical characterization has been investigated. A mixture of Ni and nano-Al2O3 particles of different ratios was added to the melted Al–Si piston alloy at 700 °C and stirred under pressure. After the Al-base-nano-composites were fabricated by squeeze casting, the microstructure and the particle distribution inside the matrix have been investigated using optical and scanning electron microscopes. Moreover, the hardness and the tensile properties of the resulted Al-base-nano-composites were evaluated at room temperature by using Vickers hardness and universal tensile testers, respectively. As a result, in most cases, it was found that the matrix showed a fine eutectic structure of short silicon constituent which appeared in the form of islands in the α-phase around some added particle agglomerations of the nano-composite structures. The tendency of this structure formation increases with the increase of Ni particle addition. As the ratio of the added particles increases, the tendency of these particles to be agglomerated also increases. Regarding the tensile properties of the fabricated Al-base-nano-composites, ultimate tensile strength is increased by adding the Ni and nano-Al2O3 particles up to 10 and 2 wt.%, respectively. Moreover, the ductility of the fabricated composites is significantly improved by increasing the added Ni particles. The composite material reinforced with 5 wt.% Ni and 2 wt.% nano-Al2O3 particles showed superior ultimate tensile strength and good ductility compared with any other added particles in this investigation.

Synthesis of Monodispersed Spherical Single Crystalline Silver Particles by Wet Chemical Process; Shisshiki kagakuho ni yoru tanbunsankyujo tankesshoginryushi no gose

Energy Technology Data Exchange (ETDEWEB)

Ueyama, Ryousuke.; Harada, Masahiro.; Ueyama, Tamotsu.; Harada, Akio. [Daiken Chemistry Industry Corporation, Osaka (Japan); Yamamoto, Takashi. [National Defence Academy, Kanagawa (Japan). Dept. of Electrical Engineering; Shiosaki, Tadashi. [Nara Institute of Science and Technology, Nara (Japan). Graduate School of Materials Science; Kuribayashi, Kiyoshi. [Teikyo University of Science and Technology, Yamanashi (Japan). Dept. of Materials

1999-01-01

Ultrafine silver monodispersed particle were prepared by wet chemical process. To decrease the reduction speed, an important factor in generating monodispersed particles is to control the following three factors: synthesis temperature, concentration of aggregation-relaxing agent added, and concentration of silver nitrate solution. Synthesis of monodispersed spherical Ag particles, used as metal powders for electrode, became possible using the nucleus grouwth reaction method. This process also allowed the control of the diameter of the powder particles. The silver particles were distributed in ta narrow particle diameter range with on average of 0.5 {mu}m. Transmission electron microscopy (TEM) revealed that single-crystalline silver particles were prepared by the present method. (author)

Synthesis, Characterization and Properties of Nanoparticles of Intermetallic Compounds

Energy Technology Data Exchange (ETDEWEB)

DiSalvo, Francis J. [Cornell Univ., Ithaca, NY (United States)

2015-03-12

The research program from 2010 to the end of the grant focused on understanding the factors important to the synthesis of single phase intermetallic nano-particles (NPs), their size, crystalline order, surface properties and electrochemical activity. The synthetic method developed is a co-reduction of mixtures of single metal precursors by strong, soluble reducing agents in a non-protic solvent, tetrahydrofuran (THF). With some exceptions, the particles obtained by room temperature reduction are random alloys that need to be annealed at modest temperatures (200 to 600 °C) in order to develop an ordered structure. To avoid significant particle size growth and agglomeration, the particles must be protected by surface coatings. We developed a novel method of coating the metal nanoparticles with KCl, a by-product of the reduction reaction if the proper reducing agents are employed. In that case, a composite product containing individual metal nanoparticles in a KCl matrix is obtained. The composite can be heated to at least 600 °C without significant agglomeration or growth in particle size. Washing the annealed product in the presence of catalyst supports in ethylene glycol removes the KCl and deposits the particles on the support. Six publications present the method and its application to producing and studying new catalyst/support combinations for fuel cell applications. Three publications concern the use of related methods to explore new lithium-sulfur battery concepts.

Solvent-Free Synthesis of Aryl Iodide Using Nano SiO2/HIO4 as a Reusable Acid Catalyst

Directory of Open Access Journals (Sweden)

A. Bamoniri

2014-07-01

Full Text Available An efficient and environmentally benign   method for the synthesis of aryl iodides have been developed by diazotization of aromatic amines with NaNO2 and nanosilica periodic acid (nano-SPIA as a green catalyst via grinding followed by a sandmeyer iodination by KI under solvent-free conditions at room temperature. The ensuing aryl diazonium salts supported on nano-SPIA were sufficiently stable to be kept at room temperature in the dry state. This method is a novel, efficient, eco-friendly route for solvent-free synthesis of aryl iodides.

Synthesis and study of nano-structured cellulose acetate based materials for energy applications

International Nuclear Information System (INIS)

Fischer, F.

2006-12-01

Nano-structured materials have unique properties (high exchange areas, containment effect) because of their very low characteristic dimensions. The elaboration way set up in this PhD work consists in applying the classical processes for the preparation of aerogel-like materials (combining sol-gel synthesis and CO 2 supercritical extraction) to cellulosic polymers. This work is divided in four parts: a literature review, the presentation and the study of the chemical synthesis that leads to cellulose acetate-based aerogel, the characterizations (chemical, structural and thermal) of the elaborated nano-materials, and finally the study of the first carbons that were obtained after pyrolysis of the organic matrix. The formulations and the sol-gel protocol lead to chemical gels by crosslinking cellulose acetate using a poly-functional iso-cyanate. The dry materials obtained after solvent extraction with supercritical CO 2 are nano-structured and mainly meso-porous. Correlations between chemical synthesis parameters (reagent concentrations, crosslinking rate and degree of polymerisation) and porous properties (density, porosity, pore size distribution) were highlighted thanks to structural characterizations. An ultra-porous reference aerogel, with a density equals to 0,245 g.cm -3 together with a meso-porous volume of 3,40 cm 3 .g -1 was elaborated. Once in granular shape, this material has a thermal conductivity of 0,029 W.m -1 .K -1 . In addition, carbon materials produced after pyrolysis of the organic matrix and after grinding are nano-structured and nano-porous, even if important structural modifications have occurred during the carbonization process. The elaborated materials are evaluated for applications in relation with energy such as thermal insulation (organic aerogels) but also for energy conversion and storage through electrochemical way (carbon aerogels). (author)

Bulk magnetic properties of CdFe2 O4 in nano-regime

Indian Academy of Sciences (India)

TECS

In recent years, the design and synthesis of nano-magnetic particles ... 1998). Two different types of spin structure were suggested .... rule integration of the pseudo-Voigt function. ... differences between measured and calculated values) that.

Polymer-directed synthesis of metal oxide-containing nanomaterials for electrochemical energy storage

Science.gov (United States)

Mai, Yiyong; Zhang, Fan; Feng, Xinliang

2013-12-01

Metal oxide-containing nanomaterials (MOCNMs) of controllable structures at the nano-scale have attracted considerable interest because of their great potential applications in electrochemical energy storage devices, such as lithium-ion batteries (LIBs) and supercapacitors. Among many structure-directing agents, polymers and macromolecules, including block copolymers (BCPs) and graphene, exhibit distinct advantages in the template-assisted synthesis of MOCNMs. In this feature article, we introduce the controlled preparation of MOCNMs employing BCPs and graphene as structure-directing agents. Typical synthetic strategies are presented for the control of structures and sizes as well as the improvement of physical properties and electrochemical performance of MOCNMs in LIBs and supercapacitors.

Combustion synthesis of CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors in a closed system

Energy Technology Data Exchange (ETDEWEB)

Peng Wenfang; Zou Shaoyu; Liu Guanxi; Xiao Quanlan; Zhang Rui; Xie Lijuan; Cao Liwei [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Meng Jianxin, E-mail: tmjx@jnu.edu.cn [Institute of Nano-Chemistry, Jinan University, Guangzhou 510632 (China); Liu Yingliang [Institute of Nano-Chemistry, Jinan University, Guangzhou 510632 (China)

2011-06-09

Highlights: > CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors can be prepared by a single-step combustion method. > The ignition temperature is the lowest in the combustion synthesis of Ce{sup 3+}/Eu{sup 2+} doped phosphors. > The as-prepared nano-phosphors give a uniform particle size in the range of 15-20 nm and have highly dispersity and fluorescence intensity. > It is a convenient method for preparation of monodispersed oxide nano-phosphors, especially those being sensitive to air at high temperature. - Abstract: The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors were successfully prepared by a single-step combustion method at an ignition temperature as low as 200 deg. C in a closed autoclave using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results revealed that CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors can be conveniently prepared at an ignition temperature as low as 200 deg. C, which was much lower than that in the ordinary combustion methods. The optimized ignition temperature was 220 deg. C. The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors give a uniform particle size in the range of 15-20 nm. The low ignition temperature and the addition of PEG4000 dispersant play important roles in the formation of small sized nanoparticles. The as-prepared nano-phosphors were incompact aggregates, but highly dispersed nano-phosphors can be obtained after further ultrasonic treatment. The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors give satisfactory luminescence characteristic benefiting from the closed circumstance, in which cerium atoms can be isolated from the oxidizing atmosphere and non-fluorescent Ce{sup 4+} ions can be ruled out. The present highly dispersed CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors with efficient fluorescence are promising in the field of biological labeling

Synthesis and characterization of porous metal oxides and desulfurization studies of sulfur containing compounds

Science.gov (United States)

Garces Trujillo, Hector Fabian

This thesis contains two parts: 1) synthesis and characterization of porous metal oxides that include zinc oxide and a porous mixed-valent manganese oxide with an amorphous structure (AMO) 2) the desulfurization studies for the removal of sulfur compounds. Zinc oxide with different nano-scale morphologies may result in various porosities with different adsorption capabilities. A tunable shape microwave synthesis of ZnO nano-spheres in a co-solvent mixture is presented. The ZnO nano-sphere material is investigated as a desulfurizing sorbent in a fixed bed reactor in the temperature range 200 to 400 °C and compared with ZnO nanorods and platelet-like morphologies. Fresh and sulfided materials were characterized by X-ray diffraction (XRD), BET specific surface area, pore volume, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (SEM/EDX), Raman spectroscopy, and thermogravimetric analysis (TGA). The tunable shape microwave synthesis of ZnO presents a high sulfur sorption capacity at temperatures as low as 200 °C which accounts for a three and four fold enhancement over the other preparations presented in this work, and reached 76 % of the theoretical sulfur capacity (TSC) at 300 °C. Another ZnO material with a bimodal micro- and mesopore size distribution investigated as a desulfurizing sorbent presents a sorption capacity that reaches 87% of the theoretical value for desulfurization at 400 °C at breakthrough time. A deactivation model that considers the activity of the solid reactant was used to fit the experimental data. Good agreement between the experimental breakthrough curves and the model predictions are obtained. Manganese oxides are a type of metal oxide materials commonly used in catalytic applications. Little is known about the adsorption capabilities for the removal of sulfur compounds. One of these manganese oxides; amorphous manganese oxide (AMO) is highly promising material for low temperature sorption processes. Amorphous

AFM of metallic nano-particles and nano-structures in heavily irradiated NaCl

OpenAIRE

Gaynutdinov, R; Vainshtein, DI; Hak, SJ; Tolstikhina, A; Den Hartog, HW

2003-01-01

AFM investigations are reported for heavily, electron irradiated NaCl crystals in ultra high vacuum (UHV) in the non-contact mode-with an UHV AFM/STM Omicron system. To avoid chemical reactions between the radiolytic Na and oxygen and water, the irradiated samples were cleaved and prepared for the experiments in UHV At the surface of freshly cleaved samples, we have observed sodium nano-precipitates with shapes, which depend on the irradiation dose and the volume fraction of the radiolytic Na...

Effects of SiO2 nano-particles on tribological and mechanical properties of aluminum matrix composites by different dispersion methods

Science.gov (United States)

Azadi, Mahboobeh; Zolfaghari, Mehrdad; Rezanezhad, Saeid; Azadi, Mohammad

2018-05-01

This study has been presented with mechanical properties of aluminum matrix composites, reinforced by SiO2 nano-particles. The stir casting method was employed to produce various aluminum matrix composites. Different composites by varying the SiO2 nano-particle content (including 0.5 and 1 weight percents) and two dispersion methods (including ball-milling and pre-heating) were made. Then, the density, the hardness, the compression strength, the wear resistance and the microstructure of nano-composites have been studied in this research. Besides, the distribution of nano-particles in the aluminum matrix for all composites has been also evaluated by the field emission scanning electron microscopy (FESEM). Obtained results showed that the density, the elongation and the ultimate compressive strength of various nano-composites decreased by the presence of SiO2 nano-particles; however, the hardness, the wear resistance, the yield strength and the elastic modulus of composites increased by auditioning of nano-particles to the aluminum alloy. FESEM images indicated better wetting of the SiO2 reinforcement in the aluminum matrix, prepared by the pre-heating dispersion method, comparing to ball-milling. When SiO2 nano-particles were added to the aluminum alloy, the morphology of the Si phase and intermetallic phases changed, which enhanced mechanical properties. In addition, the wear mechanism plus the friction coefficient value were changed for various nano-composites with respect to the aluminum alloy.

Active coated nano-particle excited by an arbitrarily located electric Hertzian dipole — resonance and transparency effects

DEFF Research Database (Denmark)

Arslanagic, Samel; Ziolkowski, Richard W.

2010-01-01

The present work investigates the optical properties of active coated spherical nano-particles excited by an arbitrarily located electric Hertzian dipole. The nano-particles are made of specific dielectric and plasmonic materials. The spatial near-field distribution as well as the normalized...

Synthesis of Carbon Nano tubes: A Revolution in Material Science for the Twenty-First Century

International Nuclear Information System (INIS)

Allaf, Abd. W.

2003-01-01

The aim of this work is to explain the preparation procedures of single walled carbon nano tubes using arc discharge technique. The optimum conditions of carbon nano tubes synthesis are given. It should be pointed out that this sort of materials would be the twenty-first century materials

Reviewing the Tannic Acid Mediated Synthesis of Metal Nanoparticles

Directory of Open Access Journals (Sweden)

Tufail Ahmad

2014-01-01

Full Text Available Metal nanoparticles harbour numerous exceptional physiochemical properties absolutely different from those of bulk metal as a function of their extremely small size and large superficial area to volume. Naked metal nanoparticles are synthesized by various physical and chemical methods. Chemical methods involving metal salt reduction in solution enjoy an extra edge over other protocols owing to their relative facileness and capability of controlling particle size along with the attribute of surface tailoring. Although chemical methods are the easiest, they are marred by the use of hazardous chemicals such as borohydrides. This has led to inclination of scientific community towards eco-friendly agents for the reduction of metal salts to form nanoparticles. Tannic acid, a plant derived polyphenolic compound, is one such agent which embodies characteristics of being harmless and environmentally friendly combined with being a good reducing and stabilizing agent. In this review, first various methods used to prepare metal nanoparticles are highlighted and further tannic acid mediated synthesis of metal nanoparticles is emphasized. This review brings forth the most recent findings on this issue.

Reviewing the Tannic Acid Mediated Synthesis of Metal Nanoparticles

International Nuclear Information System (INIS)

Ahmad, T.

2014-01-01

Metal nanoparticles harbour numerous exceptional physiochemical properties absolutely different from those of bulk metal as a function of their extremely small size and large superficial area to volume. Naked metal nanoparticles are synthesized by various physical and chemical methods. Chemical methods involving metal salt reduction in solution enjoy an extra edge over other protocols owing to their relative facileness and capability of controlling particle size along with the attribute of surface tailoring. Although chemical methods are the easiest, they are marred by the use of hazardous chemicals such as borohydrides. This has led to inclination of scientific community towards eco-friendly agents for the reduction of metal salts to form nanoparticles. Tannic acid, a plant derived polyphenolic compound, is one such agent which embodies characteristics of being harmless and environmentally friendly combined with being a good reducing and stabilizing agent. In this review, first various methods used to prepare metal nanoparticles are highlighted and further tannic acid mediated synthesis of metal nanoparticles is emphasized. This review brings forth the most recent findings on this issue.

Green chemistry synthesis of nano-cuprous oxide.

Science.gov (United States)

Ceja-Romero, L R; Ortega-Arroyo, L; Ortega Rueda de León, J M; López-Andrade, X; Narayanan, J; Aguilar-Méndez, M A; Castaño, V M

2016-04-01

Green chemistry and a central composite design, to evaluate the effect of reducing agent, temperature and pH of the reaction, were employed to produce controlled cuprous oxide (Cu2O) nanoparticles. Response surface method of the ultraviolet-visible spectroscopy is allowed to determine the most relevant factors for the size distribution of the nanoCu2O. X-ray diffraction reflections correspond to a cubic structure, with sizes from 31.9 to 104.3 nm. High-resolution transmission electron microscopy reveals that the different shapes depend strongly on the conditions of the green synthesis.

Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach.

Science.gov (United States)

Midander, Klara; Elihn, Karine; Wallén, Anna; Belova, Lyuba; Karlsson, Anna-Karin Borg; Wallinder, Inger Odnevall

2012-06-15

Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM(10) and PM(2.5) were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison. The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm(3) (7500 to 20000 particles/cm(3)), only 190 particles/cm(3) were larger than 250 nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM(10) and PM(2.5) identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants. This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols. Copyright © 2012 Elsevier B.V. All rights reserved.

Coupling Fe0 nano particles with living and dead Azolla filicoloides to improve removal of methylene blue from aqueous solution

Science.gov (United States)

Rakhshaee, Roohan

2015-11-01

Fe0 nano particles (FNPs) were connected to the cell wall of the dead and living Azolla filicoloides as an aquatic fern, individually. FNPs mean size was decreased due to the stabilization, especially using the living one. It was compared the results of X-ray photoelectron spectroscopy (XPS), saturation magnetization (Ms), zeta potential (ZP) and thermal analysis (DSC and TGA) of the dead and living Azolla connected to FNPs, and also the findings of potentiometric titration (PT) of the cell wall's pectin of the dead and living Azolla. It was confirmed (by XRD and XPS) that Fe0 nano particles when were connected to the living Azolla did not produce Fe3O4 due to oxidation unlike the bare FNPs and the connected form to the dead Azolla, by reason of the more stabilization (more surface protection) of nano iron particles after connecting to the living Azolla. To adsorb methylene blue by these agents at the optimum pre-treatment pH 10 and adsorption pH 8, the parameters of equilibrium sorption, rate constant of second-order sorption and activation energy were obtained as: living Azolla-FNPs > dead Azolla-FNPs > FNPs > dead Azolla, while, their thermodynamic parameters (ΔG°, ΔH° and ΔS°) had the reverse arrangement. It was also studied the various factors rule such as photoperiod and the presence of heavy metals on the living Azolla growth coupled with FNPs and its MB removal ability.

Neuroprotective effect of curcumin-loaded lactoferrin nano particles against rotenone induced neurotoxicity.

Science.gov (United States)

Bollimpelli, V Satish; Kumar, Prashant; Kumari, Sonali; Kondapi, Anand K

2016-05-01

Curcumin is known to have neuroprotective role and possess antioxidant, anti-inflammatory activities. Rotenone, a flavonoid induced neurotoxicity in dopaminergic cells is being widely studied in Parkinson's Disease (PD) research. In the present study, curcumin loaded lactoferrin nano particles prepared by sol-oil chemistry were used to protect dopaminergic cell line SK-N-SH against rotenone induced neurotoxicity. These curcumin loaded nano particles were of 43-60 nm diameter size and around 100 nm hydrodynamic size as assessed by transmission electron microscopy, atomic force microscopy and dynamic light scattering analysis respectively. The encapsulation efficiency was 61.3% ± 2.4%. Cellular uptake of curcumin through these nano particles was confirmed by confocal imaging and spectrofluorimetric analysis. The curcumin loaded lactoferrin nanoparticles showed greater intracellular drug uptake, sustained retention and greater neuroprotection than soluble counterpart. Neuroprotective activity was characterized through viability assays and by estimating ROS levels. Furthermore rotenone induced PD like features were characterized by decrease in tyrosine hydroxylase expression and increase in α-synuclein expression. Taken together curcumin loaded lactoferrin nanoparticles could be a promising drug delivery strategy against neurotoxicity in dopaminergic neurons. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structural coloration of metallic surfaces with micro/nano-structures induced by elliptical vibration texturing

Science.gov (United States)

Yang, Yang; Pan, Yayue; Guo, Ping

2017-04-01

Creating orderly periodic micro/nano-structures on metallic surfaces, or structural coloration, for control of surface apparent color and optical reflectivity has been an exciting research topic over the years. The direct applications of structural coloration include color marking, display devices, and invisibility cloak. This paper presents an efficient method to colorize metallic surfaces with periodic micro/nano-gratings using elliptical vibration texturing. When the tool vibration is coupled with a constant cutting velocity, controlled periodic ripples can be generated due to the overlapping tool trajectory. These periodic ripples with a wavelength near visible spectrum can act as micro-gratings to introduce iridescent colors. The proposed technique also provides a flexible method for color marking of metallic surfaces with arbitrary patterns and images by precise control of the spacing distance and orientation of induced micro/nano-ripples. Theoretical analysis and experimental results are given to demonstrate structural coloration of metals by a direct mechanical machining technique.

Thermodynamic and structural properties of ball-milled mixtures composed of nano-structural graphite and alkali(-earth) metal hydride

International Nuclear Information System (INIS)

Miyaoka, Hiroki; Ichikawa, Takayuki; Fujii, Hironobu

2007-01-01

Hydrogen desorption properties of mechanically milled materials composed of nano-structural hydrogenated-graphite (C nano H x ) and alkali(-earth) metal hydride (MH; M = Na, Mg and Ca) were investigated from the thermodynamic and structural points of view. The hydrogen desorption temperature for all the C nano H x and MH composites was obviously lower than that of the corresponding each hydride. In addition, the desorption of hydrocarbons from C nano H x was significantly suppressed by making composite of C nano H x with MH, even though C nano H x itself thermally desorbs a considerably large amount of hydrocarbons. These results indicate that an interaction exists between C nano H x and MH, and hydrogen in both the phases is destabilized by a close contact between polar C-H groups in C nano H x and the MH solid phase. Moreover, a new type of chemical bonding between the nano-structural carbon (C nano ) and the Li, Ca, or Mg metal atoms may be formed after hydrogen desorption. Thus, the above metal-C-H system would be recognized as a new family of H-storage materials

Preparation of nano-biomaterials with Leptolyngbia foveolarum and heavy metal biosorption by free and immobilized algal cells

International Nuclear Information System (INIS)

Toncheva-Panova, T.; Pouneva, I.; Sholeva, M.; Chernev, G.

2010-01-01

Using the sol-gel procedure nano-biomaterials with incorporation of Leptolyngbia foveolarum in the silica matrix were manufactured. The immobilization of algal cells was confirmed with Scanning Electron Microscopy (SEM) investigations and photos. Observation of nano-biomaterials with Atomic Force Microscopy (AFM) shows nanostructure with well-defined nanounits and their aggregates. The potential of the Antarctic isolate L. foveolarum for sorption of Cu 2+ and Cd 2+ was studied by incubation of free algal cells and those immobilized in nano-biomaterials in the salts solutions of the two heavy metals. The rest of the heavy metal was determined with inductively coupled plasma atomic emission spectrometer (ICP-AES). It was established that the heavy metal biosorption capacity demonstrated by the free Leptolyngbia cells was retained after their incorporation in the nano-matrices. Free cells as well as embedded in silica nano-matrix sequestered the two heavy metals with greater affinity for copper. The highest binding capacity, 76% of the initial Cu 2+ concentration possessed nano-biomaterials with incorporated vegetative L. foveolarum cells, compared to 68% of free cells. For cadmium the degree of biosorption was lower - 35% by free cells and 30.2% by those incorporated in the biocer. (authors)

Biomimetic synthesis of noble metal nanocrystals

Science.gov (United States)

Chiu, Chin-Yi

At the nanometer scale, the physical and chemical properties of materials heavily depend on their sizes and shapes. This fact has triggered considerable efforts in developing controllable nanomaterial synthesis. The controlled growth of colloidal nanocrystal is a kinetic process, in which high-energy facets grow faster and then vanish, leading to a nanocrystal enclosed by low-energy facets. Identifying a surfactant that can selectively bind to a particular crystal facet and thus lower its surface energy, is critical and challenging in shape controlled synthesis of nanocrystals. Biomolecules exhibiting exquisite molecular recognition properties can be exploited to precisely engineer nanostructured materials. In the first part of my thesis, we employed the phage display technique to select a specific multifunctional peptide sequence which can bind on Pd surface and mediate Pd crystal nucleation and growth, achieving size controlled synthesis of Pd nanocrystals in aqueous solution. We further demonstrated a rational biomimetic approach to the predictable synthesis of nanocrystals enclosed by a particular facet in the case of Pt. Specifically, Pt {100} and Pt {111} facet-specific peptides were identified and used to synthesize Pt nanocubes and Pt nano-tetrahedrons, respectively. The mechanistic studies of Pt {111} facet-specific peptide had led us to study the facet-selective adsorption of aromatic molecules on noble metal surfaces. The discoveries had achieved the development of design strategies to select facet-selective molecules which can synthesize nanocrystals with expected shapes in both Pt and Pd system. At last, we exploited Pt facet-specific peptides and controlled the molecular interaction to produce one- and three- dimensional nanostructures composed of anisotropic nanoparticles in synthetic conditions without supramolecular pre-organization, demonstrating the full potential of biomolecules in mediating material formation process. My research on biomimetic

Silicon nano-particles : On Route to a Sustainable Mobility

NARCIS (Netherlands)

Munao, D.

2012-01-01

The area of nanotechnology is one of the most active fields in science today. It is often seen as the area that could lead to substantial progress in terms of finding new materials with new properties. In this respect, silicon nano-particles are found to be greatly attractive because of their

Anti-UV Radiation Textiles Designed by Embracing with Nano-MIL (Ti, In)-Metal Organic Framework.

Science.gov (United States)

Emam, Hossam E; Abdelhameed, Reda M

2017-08-23

Protective textiles against harmful solar radiation are quite important materials for outdoor workers to secure their skin from several diseases. Current report focuses on production of anti-ultraviolet radiation (UVR) textiles by incorporation of nano-metal-organic frameworks (n-MOFs). Two different MIL-MOFs, namely, MIL-68(In)-NH 2 and MIL-125(Ti)-NH 2 , were immediately formed inside natural textiles (cotton and silk) matrix in nano size using quite simple and one-pot process. The formation of n-MIL-MOFs inside textiles were confirmed by using electron microscope and X-ray diffraction. Different size and morphology were seen depending on textile type reflecting the textiles' chemical composition role in the nature of prepared MIL-MOFs. For MIL-68(In)-NH 2 , particles with size distribution of 70.6-44.5 nm in cotton and 81.3-52.2 nm in silk were detected, while crystalline disc of MIL-125(Ti)-NH 2 was clearly seen inside textiles. The natural textiles exhibited full UVR blocking after modification, and the UV protection factor (UPF) was linearly proportional with MIL-MOFs and metal contents. Whatever metal type, direct incorporation of MIL-MOF contents greater than or equal to 10.4 g/kg was sufficient to attain excellent UV blocking property. Although 38.5-41.0% of MIL-MOFs was lost during five washings, the washed samples showed very good blocking rate (UPF = 26.7-36.2) supporting good laundering durability.

Motion of Adsorbed Nano-Particles on Azobenzene Containing Polymer Films

Directory of Open Access Journals (Sweden)

Sarah Loebner

2016-12-01

Full Text Available We demonstrate in situ recorded motion of nano-objects adsorbed on a photosensitive polymer film. The motion is induced by a mass transport of the underlying photoresponsive polymer material occurring during irradiation with interference pattern. The polymer film contains azobenzene molecules that undergo reversible photoisomerization reaction from trans- to cis-conformation. Through a multi-scale chain of physico-chemical processes, this finally results in the macro-deformations of the film due to the changing elastic properties of polymer. The topographical deformation of the polymer surface is sensitive to a local distribution of the electrical field vector that allows for the generation of dynamic changes in the surface topography during irradiation with different light interference patterns. Polymer film deformation together with the motion of the adsorbed nano-particles are recorded using a homemade set-up combining an optical part for the generation of interference patterns and an atomic force microscope for acquiring the surface deformation. The particles undergo either translational or rotational motion. The direction of particle motion is towards the topography minima and opposite to the mass transport within the polymer film. The ability to relocate particles by photo-induced dynamic topography fluctuation offers a way for a non-contact simultaneous manipulation of a large number of adsorbed particles just in air at ambient conditions.

Production and Application of Olivine Nano-Silica in Concrete

Science.gov (United States)

Mardiana, Oesman; Haryadi

2017-05-01

The aim of this research was to produce nano silica by synthesis of nano silica through extraction and dissolution of ground olivine rock, and applied the nano silica in the design concrete mix. The producing process of amorphous silica used sulfuric acid as the dissolution reagent. The separation of ground olivine rock occurred when the rock was heated in a batch reactor containing sulfuric acid. The results showed that the optimum mole ratio of olivine- acid was 1: 8 wherein the weight ratio of the highest nano silica generated. The heating temperature and acid concentration influenced the mass of silica produced, that was at temperature of 90 °C and 3 M acid giving the highest yield of 44.90%. Characterization using Fourier Transform Infrared (FTIR ) concluded that amorphous silica at a wavenumber of 1089 cm-1 indicated the presence of siloxane, Si-O-Si, stretching bond. Characterization using Scanning Electron Microscope - Energy Dispersive Spectroscopy (SEM-EDS) showed the surface and the size of the silica particles. The average size of silica particles was between 1-10 μm due to the rapid aggregation of the growing particles of nano silica into microparticles, caused of the pH control was not fully achieved.

Synthesis of Single-Walled Carbon Nanotubes: Effects of Active Metals, Catalyst Supports, and Metal Loading Percentage

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Wei-Wen Liu

2013-01-01

Full Text Available The effects of active metals, catalyst supports, and metal loading percentage on the formation of single-walled carbon nanotubes (SWNTs were studied. In particular, iron, cobalt, and nickel were investigated for SWNTs synthesis. Iron was found to grow better-quality SWNTs compared to cobalt and nickel. To study the effect of catalyst supports, magnesium oxide, silicon oxide, and aluminium oxide were chosen for iron. Among the studied supports, MgO was identified to be a suitable support for iron as it produced SWNTs with better graphitisation determined by Raman analysis. Increasing the iron loading decreased the quality of SWNTs due to extensive agglomeration of the iron particles. Thus, lower metal loading percentage is preferred to grow better-quality SWNTs with uniform diameters.

Flow chemistry to control the synthesis of nano and microparticles for biomedical applications.

Science.gov (United States)

Hassan, Natalia; Oyarzun-Ampuero, Felipe; Lara, Pablo; Guerrero, Simón; Cabuil, Valérie; Abou-Hassan, Ali; Kogan, Marcelo J

2014-03-01

In this article we review the flow chemistry methodologies for the controlled synthesis of different kind of nano and microparticles for biomedical applications. Injection mechanism has emerged as new alternative for the synthesis of nanoparticles due to this strategy allows achieving superior levels of control of self-assemblies, leading to higher-ordered structures and rapid chemical reactions. Self-assembly events are strongly dependent on factors such as the local concentration of reagents, the mixing rates, and the shear forces, which can be finely tuned, as an example, in a microfluidic device. Injection methods have also proved to be optimal to elaborate microsystems comprising polymer solutions. Concretely, extrusion based methods can provide controlled fluid transport, rapid chemical reactions, and cost-saving advantages over conventional reactors. We provide an update of synthesis of nano and microparticles such as core/shell, Janus, nanocrystals, liposomes, and biopolymeric microgels through flow chemistry, its potential bioapplications and future challenges in this field are discussed.

Synthesis and characterization of poly[N-isopropylacrylamide-co-1-(N,N-bis-carboxymethyl)amino-3-allylglycerol] grafted to magnetic nano-particles for the extraction and determination of fluvoxamine in biological and pharmaceutical samples.

Science.gov (United States)

Panahi, Homayon Ahmad; Tavanaei, Yasamin; Moniri, Elham; Keshmirizadeh, Elham

2014-06-06

In this research, a novel method is reported for the surface grafting of N-isopropylacrylamide as a thermosensitive agent and 1-(N,N-bis-carboxymethyl)amino-3-allylglycerol with an affinity toward fluvoxamine onto magnetic nano-particles modified by 3-mercaptopropyltrimethoxysilane. The grafted nano-particles were characterized by Fourier transform infrared spectroscopy, elemental analysis, and thermogravimetric analysis. The surface morphology was studied with scanning electron microscopy and transmission electron microscopy. The resulting grafted nano-particles were used in solid phase extraction and determining of trace fluvoxamine in biological human fluids and pharmaceutical samples. The profile of the fluvoxamine uptake by the modified magnetic nano-particles indicated good accessibility of the active sites in the grafted copolymer. It was found that the adsorption behavior could be fitted by the Freundlich adsorption isotherm model. It was observed that a maximum amount of fluvoxamine was released at a temperature above the lower critical solution temperature of the polymer. Copyright © 2014 Elsevier B.V. All rights reserved.

Hot-wire chemical vapor synthesis for a variety of nano-materials with novel applications

International Nuclear Information System (INIS)

Dillon, A.C.; Mahan, A.H.; Deshpande, R.; Alleman, J.L.; Blackburn, J.L.; Parillia, P.A.; Heben, M.J.; Engtrakul, C.; Gilbert, K.E.H.; Jones, K.M.; To, R.; Lee, S-H.; Lehman, J.H.

2006-01-01

Hot-wire chemical vapor deposition (HWCVD) has been demonstrated as a simple economically scalable technique for the synthesis of a variety of nano-materials in an environmentally friendly manner. For example we have employed HWCVD for the continuous production of both carbon single- and multi-wall nanotubes (SWNTs and MWNTs). Unanticipated hydrogen storage on HWCVD-generated MWNTs has led insight into the adsorption mechanism of hydrogen on metal/carbon composites at near ambient temperatures that could be useful for developing a vehicular hydrogen storage system. Recent efforts have been focused on growing MWNT arrays on thin nickel films with a simple HWCVD process. New data suggests that these MWNT arrays could replace the gold black coatings currently used in pyroelectric detectors to accurately measure laser power. Finally, we have very recently employed HWCVD for the production of crystalline molybdenum and tungsten oxide nanotubes and nanorods. These metal oxide nanorods and nanotubes could have applications in catalysis, batteries and electrochromic windows or as gas sensors. A summary of the techniques for growing these novel materials and their various potential applications is provided

Shielding properties of the ordinary concrete loaded with micro- and nano-particles against neutron and gamma radiations.

Science.gov (United States)

Mesbahi, Asghar; Ghiasi, Hosein

2018-06-01

The shielding properties of ordinary concrete doped with some micro and nano scaled materials were studied in the current study. Narrow beam geometry was simulated using MCNPX Monte Carlo code and the mass attenuation coefficient of ordinary concrete doped with PbO 2 , Fe 2 O 3 , WO 3 and H 4 B (Boronium) in both nano and micro scales was calculated for photon and neutron beams. Mono-energetic beams of neutrons (100-3000 keV) and photons (142-1250 keV) were used for calculations. The concrete doped with nano-sized particles showed higher neutron removal cross section (7%) and photon attenuation coefficient (8%) relative to micro-particles. Application of nano-sized material in the composition of new concretes for dual protection against neutrons and photons are recommended. For further studies, the calculation of attenuation coefficients of these nano-concretes against higher energies of neutrons and photons and different particles are suggested. Copyright © 2018 Elsevier Ltd. All rights reserved.

Book Review: Nano physics & Nano technology

Directory of Open Access Journals (Sweden)

Abdolkhaled Zaree

2012-12-01

Full Text Available During last decades, there are a lot of emphases on studying material behavior in atomic scale. In most scientific and engineering fields, one can see the effect of nanotechnology. The aim of nanoscience is to design and fabrication of new and applicable materials. Nowadays, Nano is a popular science which chemists, physicist, doctors, engineers, financial managers and environment's fans for creating a good life via nanoscience have a great cooperation with each others. Materials in nano scale such as nanotubes and nanowires have extraordinary properties which by optimization of these properties in nano scale and then develop these properties to macro scale, they've been challenging issues. For instance, materials in nano scale improve mechanical properties of polymers and metallic materials via nano particles and on the other hand by producing a thin film on surfaces improve surface hardening. Besides, nanotechnology is in hi-tech industries such as magnetic devices, surface coating, and biomaterial, material having sensors, polymers, gels, ceramics and intelligent membrane. Nano-carbon tubes are considered intelligent due to the fact that they couple electrochemical and elastic properties simultaneously, hence have greater activation energy density in comparison with other intelligent materials. Studying nanoscience is important because it causes the life to be better. Future Materials and structures will have a lot of outstanding properties. Intelligent machines can repair, recycle and reconstruct themselves. All these features are only possible in nano zone. Nano in engineering science can provide the possibility of making light missiles for exploring space. The reduced weight can be achieved by replacing traditional materials with hybrid nanocomposites.

Method of producing nano-scaled inorganic platelets

Science.gov (United States)

Zhamu, Aruna; Jang, Bor Z.

2012-11-13

The present invention provides a method of exfoliating a layered material (e.g., transition metal dichalcogenide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm. The method comprises (a) dispersing particles of a non-graphite laminar compound in a liquid medium containing therein a surfactant or dispersing agent to obtain a stable suspension or slurry; and (b) exposing the suspension or slurry to ultrasonic waves at an energy level for a sufficient length of time to produce separated nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites.

Sustainable Utility of Magnetically Recyclable Nano-Catalysts in Water: Applications in Organic Synthesis

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Manoj B. Gawande

2013-10-01

Full Text Available Magnetically recyclable nano-catalysts and their use in aqueous media is a perfect combination for the development of greener sustainable methodologies in organic synthesis. It is well established that magnetically separable nano-catalysts avoid waste of catalysts or reagents and it is possible to recover >95% of catalysts, which is again recyclable for subsequent use. Water is the ideal medium to perform the chemical reactions with magnetically recyclable nano-catalysts, as this combination adds tremendous value to the overall benign reaction process development. In this review, we highlight recent developments inthe use of water and magnetically recyclable nano-catalysts (W-MRNs for a variety of organic reactions namely hydrogenation, condensation, oxidation, and Suzuki–Miyaura cross-coupling reactions, among others.

Rapidly patterning micro/nano devices by directly assembling ions and nanomaterials

OpenAIRE

Na Liu; Feifei Wang; Lianqing Liu; Haibo Yu; Shaorong Xie; Jun Wang; Yuechao Wang; Gwo-Bin Lee; Wen J. Li

2016-01-01

The synthesis and assembly of components are key steps in micro/nano device manufacturing. In this article, we report an optically controlled assembly method that can rapidly pattern micro/nano devices by directly assembling ions and nanomaterials without expensive physical masks and complex etching processes. Utilizing this controllable process, different types of device components (e.g., metallic and semiconductor) can be fabricated and assembled in 10?30?seconds, which is far more rapid an...

Fabrication of magnetic nano liquid metal fluid through loading of Ni nanoparticles into gallium or its alloy

Energy Technology Data Exchange (ETDEWEB)

Xiong, Mingfeng; Gao, Yunxia [Key Lab of Cryogenics and Beijing Key Lab of CryoBiomedical Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Jing, E-mail: jliu@mail.ipc.ac.cn [Key Lab of Cryogenics and Beijing Key Lab of CryoBiomedical Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China)

2014-03-15

In this study, Ni nanoparticles were loaded into the partially oxidized gallium and its alloys to fabricate desired magnetic nanofluid. It was disclosed that the Ni nanoparticles sharply increased the freezing temperature and latent heat of the obtained magnetic nano liquid metal fluid, while the melting process was less affected. For the gallium sample added with 10 vol% coated Ni particles, a hysteresis loop was observed and the magnetization intensity decreased with the increase of the temperature. The slope for the magnetization-temperature curve within 10–30 K was about 20 times of that from 40 K to 400 K. Further, the dynamic impact experiments of striking magnetic liquid metal droplets on the magnet revealed that the regurgitating of the leading edge of the liquid disk and the subsequent wave that often occurred in the gallium-indium droplets would disappear for the magnetic fluids case due to attraction force of the magnet. - Graphical abstract: High speed videos for the impact of striking GaIn{sub 24.5} based magnetic liquid metal droplets on a magnet plate. - Highlights: • A feasible way to fabricate magnetic nano liquid metal fluid was presented. • Ni nanoparticles sharply increased freezing temperature and latent heat of magnetic nanofluid. • A hysteresis loop phenomenon was observed for the magnetic nanofluid. • Temperature dependent magnetization spanning from 10 K to 400 K was measured. • Impact phenomena of striking magnetic droplets on magnet were disclosed.

Influence of nano-AlN particles on thermal conductivity, thermal stability and cure behavior of cycloaliphatic epoxy/trimethacrylate system

Directory of Open Access Journals (Sweden)

2011-02-01

Full Text Available We have prepared a series of nano-sized aluminium nitride (nano-AlN/cycloaliphatic epoxy/trimethacrylate (TMPTMA systems and investigated their morphology, thermal conductivity, thermal stability and curing behavior. Experimental results show that the thermal conductivity of composites increases with the nano-AlN filler content, the maximum value is up to 0.47 W/(m.K. Incorporation of a small amount of the nano-AlN filler into the epoxy/TMPTMA system improves the thermal stability. For instance, the thermal degradation temperature at 5% weight loss of nano-AlN/epoxy/TMPTMA system with only 1 wt% nano-AlN was improved by ~8ºC over the neat epoxy/TMPTMA system. The effect of nano-AlN particles on the cure behavior of epoxy/TMPTMA systems was studied by dynamic differential scanning calorimetry. The results showed that the addition of silane treated nano-AlN particles does not change the curing reaction mechanism and silane treated nano-AlN particles could bring positive effect on the processing of composite since it needs shorter pre-cure time and lower pre-temperature, meanwhile the increase of glass transition temperature of the nanocomposite improves the heat resistance.

Using the Aerasense NanoTracer for simultaneously obtaining several ultrafine particle exposure metrics

International Nuclear Information System (INIS)

Marra, J

2011-01-01

The expanding production and use of nanomaterials increases the chance of human exposure to engineered nanoparticles (NP), also referred to as ultrafine particles (UFP; ≤ 100 - 300 nm). This is particularly true in workplaces where they can become airborne and thereafter inhaled by workers during nanopowder processing. Considering the suspected hazard of many engineered UFPs, the general recommendation is to take measures for minimizing personal exposure while monitoring the UFP pollution for assessment and control purposes. The portable Aerasense NanoTracer accomplishes this UFP monitoring, either intermittently or in real time. This paper reviews its design and operational characteristics and elaborates on a number of application extensions and constraints. The NanoTracer's output signals enable several UFP exposure metrics to be simultaneously inferred. These include the airborne UFP number concentration and the number-averaged particle size, serving as characteristics of the pertaining UFP pollution. When non-hygroscopic particles are involved, the NanoTracer's output signals also allow an estimation of the lung-deposited UFP surface area concentration and the lung-deposited UFP mass concentration. It is thereby possible to distinguish between UFP depositions in the alveolar region, the trachea-bronchial region and the head airway region, respectively, by making use of the ICRP particle deposition model.

Advances and patents about grinding equipments with nano-particle jet minimum quantity lubrication.

Science.gov (United States)

Jia, Dongzhou; Li, Changhe; Wang, Sheng; Zhang, Qiang; Hou, Yali

2014-01-01

In recent years, a large number of patents have been devoted to developing minimum quantity lubrication (MQL) grinding techniques that can significantly improve both environmentally conscious and energy saving and costeffective sustainable grinding fluid alternatives. Among them, one patent is about a controllable nano-fluids jet MQL grinding system based on electrostatic atomization. Using the principle of electrostatics, it can achieve the control of droplet transfer by charging the sprayed droplets. This system can improve the uniformity of the droplet spectrum, liquid deposition efficiency and effective utilization of liquid. It can also effectively control the movement patterns of the droplets, thereby reducing the pollution of the environment and providing better health protection for workers. Although researchers accomplished profound and systematic studies on MQL, especially on nano-particles jet MQL. It can solve the shortage of MQL in cooling performance, greatly improve the working environment, save energy and reduce costs to achieve a low-carbon manufacturing. The unique lubricating performance and tribological property of solid nano-particles form nano-particle shearing films at the grinding wheel/workpiece interface, which can enhance the lubricating performance of MQL grinding. Existing studies on MQL grinding equipments, however, cannot meet the needs of the technological development. Therefore, our research provided a general introduction of the latest patients and research progress of nanoparticles jet MQL grinding equipments presented by the research team from Qingdao Technological University.

Preparation and characterization of reduced graphene oxide/copper composites incorporated with nano-SiO2 particles

International Nuclear Information System (INIS)

Zhang, Xinjiang; Dong, Pengyu; Zhang, Benguo; Tang, Shengyang; Yang, Zirun; Chen, Yong; Yang, Wenchao

2016-01-01

Reduced graphene oxide/copper (rGO/Cu) composites incorporated with nano-SiO 2 particles were successfully fabricated using the raw materials of GO dispersion, hydrophilic nano-SiO 2 and electrolytic Cu powder. The as-prepared composites were characterized by X-ray diffraction, field-emission scanning electron microscope and energy dispersive spectroscopy. Microstructural observation of the composite powders indicated that the graphene oxide (GO) was effectively reduced by N 2 H 4 ·H 2 O addition in the composite slurry, and the nano-SiO 2 particles and rGO sheets were randomly and completely mixed with Cu particles. The as-sintered composites exhibited the small rGO agglomerations in the Cu matrix, and the more nano-SiO 2 additions led to the agglomerations increase. The mechanical property testing revealed that rGO/Cu composites with nano-SiO 2 incorporation exhibited the higher hardness and strength, compared with the rGO/Cu composite and as-cast pure Cu. However, the strengthening in the composites with higher SiO 2 content accompanied with the expense of compressive ductility. Microstructural formation and strengthening mechanism of the composites are also discussed in details. - Highlights: • Nano-SiO 2 incorporated rGO/Cu composites were successfully fabricated. • The more nano-SiO 2 additions led to the agglomerations increase in the composites. • The nano-SiO 2 incorporated composites exhibited the better hardness and strength. • The formation and strengthening mechanism of the composite was discussed in detail.

Synthesis by plasma of polymer-metal materials

International Nuclear Information System (INIS)

Fernandez R, G.

2004-01-01

The objective of this work is the design of an experimental set-up to synthesize polymer- metal composites by plasma with versatility in the conditions of synthesis. The main components are a vacuum system capable to reach up to 10 -2 mbar and valves and accessories to control the pressure in the system. In order to generate the electrical discharges and the plasma, an electrical circuit with an inductive connection at 13.56 MHz of frequency was constructed. The electric field partially ionizes the reactor atmosphere where the polymer-metal composites were synthesized. The reactor has two metallic electrodes, one in front of the other, where the particles electrically charged collide against the electrodes producing ablation on them. The polymer-metal composites were synthesized by means of an inductive connection at 13.56 MHz. Aniline, 3-chlorine-ethylene and electrodes of silver (Ag) and copper (Cu) were used in a cylindrical reactor coupled with an external coil to generate glow discharges. The average pressures were 6.15 X 10 -1 and 5.2 X 10 -1 mbar for the synthesis of Poly aniline (P An) and Poly chloroethylene (PE-CI), respectively. The synthesis was performed during 60 and 180 minutes for P An and PE-CI, respectively. The polymers were formed, as films, with an average thickness of 6.42 μm for P An and, in the case of PE-CI, with an approximately growing rate of 14 ηm/W. The power in the syntheses was 30, 50, 70 and 90 W for P An and 50, 100, 120, 140 170, and 200 W for PE-CI. The characterization of the polymer-metal composites was done by energy dispersive spectroscopy to study the composition and the relation of the elements involved in the synthesis. The morphology of the films was studied by means of scanning electron microscopy. The infrared analysis (IR) was done to study the chemicals bonds and the structure of these polymers. Another important study in these materials was the behavior of the electrical conductivity (σ), which was complemented

Rapid Synthesis and Characterization of Nano sodalite Synthesized using Rice Husk Ash

International Nuclear Information System (INIS)

Siti Haslina Ahmad Rusmili; Zainab Ramli

2012-01-01

Rice husk ash (RHA) which contains more than 90 percent silica is proven to be an active silica source in zeolite synthesis. In this study, nano sodalite has been successfully synthesized hydrothermally at 60 degree Celsius using RHA as silica source in alkaline medium at various crystallization times. Commercial fumed silica was used as comparison for the silica source. Analysis by XRD has shown that pure nano sodalite was formed in 3 hours and stable up to more than 24 hours when using RHA as silica source. On the other hand, fumed silica produced pure nano sodalite only at 4 hours while a mixture of zeolites was observed outside this time range. FESEM shows a worm-like morphology of nano sodalite in the size range of 50-100 nm while FTIR shows the formation of aluminosilicates bonds. Analysis on the dissolved silica in the gel reaction mixture demonstrates the decreasing mass of silica after prolong time of crystallization which indicates the consumption of the dissolved silica in crystal growth of nano sodalite. This study shows that RHA is a better silica source in stabilizing the nano sodalite phase in oxide gel reaction mixture as compared to fumed silica. (author)

SiO2@FeSO4 nano composite: A recoverable nano-catalyst for eco-friendly synthesis oximes of carbonyl compounds

Directory of Open Access Journals (Sweden)

Mostafa Karimkoshteh

2016-01-01

Full Text Available Various aldoximes and ketoximes synthesis of corresponding aldehydes and ketones in the presence of SiO2@FeSO4 nano composite as recoverable nano catalyst and NH2OH·HCl. The SiO2@FeSO4 nano composite system was carried out between 10 to 15 min in oil bath (70-80 °C under solvent-free condition in excellent yields in addition this protocol can be used for industrial scales. This method offers some advantages in term of clean reaction conditions, easy work-up procedure, short reaction time, applied to convert α-diketones to α-diketoximes (as longer than other carbonyl compounds, α,β-unsaturated aldehydes and ketones to corresponding oximes and suppression of any side product. So we think that NH2OH•HCl/SiO2@FeSO4 nano composite system could be considered a new and useful addition to the present methodologies in this area. Structure of products and nano composite elucidation was carried out by 1H NMR, 13C NMR, FT-IR, scanning electron microscopy (SEM.

Self-Templated Stepwise Synthesis of Monodispersed Nanoscale Metalated Covalent Organic Polymers for In Vivo Bioimaging and Photothermal Therapy.

Science.gov (United States)

Shi, Yanshu; Deng, Xiaoran; Bao, Shouxin; Liu, Bei; Liu, Bin; Ma, Ping'an; Cheng, Ziyong; Pang, Maolin; Lin, Jun

2017-09-05

Size- and shape-controlled growth of nanoscale microporous organic polymers (MOPs) is a big challenge scientists are confronted with; meanwhile, rendering these materials for in vivo biomedical applications is still scarce. In this study, a monodispersed nanometalated covalent organic polymer (MCOP, M=Fe, Gd) with sizes around 120 nm was prepared by a self-templated two-step solution-phase synthesis method. The metal ions (Fe 3+ , Gd 3+ ) played important roles in generating a small particle size and in the functionalization of the products during the reaction with p-phenylenediamine (Pa). The resultant Fe-Pa complex was used as a template for the subsequent formation of MCOP following the Schiff base reaction with 1,3,5-triformylphloroglucinol (Tp). A high tumor suppression efficiency for this Pa-based COP is reported for the first time. This study demonstrates the potential use of MCOP as a photothermal agent for photothermal therapy (PTT) and also provides an alternative route to fabricate nano-sized MCOPs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surface modification and particles size distribution control in nano-CdS/polystyrene composite film

International Nuclear Information System (INIS)

Min Zhirong; Ming Qiuzhang; Hai Chunliang; Han Minzeng

2003-01-01

Preparation of nano-CdS particles with surface thiol modification by microemulsion method and their influences on the particle size distribution in highly filled polystyrene-based composites were studied. The modified nano-CdS was characterized by X-ray photoelectron spectroscopy (XPS), light absorption and emission measurements to reveal the morphologies of the surface modifier, which are consistent with the surface molecules packing calculation. The morphologies of the surface modifier exerted a great influence not only on the optical performance of the particles themselves, but also on the size distribution of the particle in polystyrene matrix. A monolayer coverage with tightly packed thiol molecules was believed to be most effective in promoting a uniform particle size distribution and eliminating the surface defects that cause radiationless recombination. Control of the particles size distribution in polystyrene can be attained by adjusting surface coverage status of the thiol molecules based on the strong interaction between the surface modifier and the matrix

Tracking the pathway of diesel exhaust particles from the nose to the brain by X-ray florescence analysis

Energy Technology Data Exchange (ETDEWEB)

Matsui, Yasuto [Department of Urban and Environmental Engineering, Kyoto University, Katsura, Nishigyo-ku, Kyoto 606-8501 (Japan)], E-mail: y.matsui@health.env.kyoto-u.ac.jp; Sakai, Nobumitsu [Department of Urban and Environmental Engineering, Kyoto University, Katsura, Nishigyo-ku, Kyoto 606-8501 (Japan)], E-mail: sakai@health.env.kyoto-u.ac.jp; Tsuda, Akira [Molecular and Integrative Physiological Sciences, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States)], E-mail: atsuda@hsph.harvard.edu; Terada, Yasuko [JASRI, SPring-8, 1-1-1 Kouto, Sayo, Sayo-gun, Hyogo 679-5148 (Japan)], E-mail: yterada@spring8.or.jp; Takaoka, Masaki [Department of Urban and Environmental Engineering, Kyoto University, Katsura, Nishigyo-ku, Kyoto 606-8501 (Japan)], E-mail: takaoka@epsehost.env.kyoto-u.ac.jp; Fujimaki, Hidekazu [Division of Environmental Health Sciences, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)], E-mail: fujimaki@nies.go.jp; Uchiyama, Iwao [Department of Urban and Environmental Engineering, Kyoto University, Katsura, Nishigyo-ku, Kyoto 606-8501 (Japan)], E-mail: uchiyama@health.env.kyoto-u.ac.jp

2009-08-15

Studies have shown that exposure to nano-sized particles (< 50 nm) result in their translocation to the central nervous system through the olfactory nerve. Translocation commonly occurs via inhalation, ingestion and skin uptake. Little information is available on the specific pathway of cellular localization of nano-sized particles in the olfactory bulb. The nano-sized particles entrance into the postsynaptics cell is of particular interest because the mitral cell projects to the central nucleus of the amygdala and the piriform cortex. Therefore, our objective in this follow-up study has been to determine whether or not the mitral cells project nano-sized particles to the brain. Nano-sized particles in this study were generated using diesel exhaust. Lab mice were exposed for a period of 4 weeks. We employed synchrotron radiation (SPring-8, Japan) to determine the concentration levels of metal in the olfactory neuron pathway. Metal levels were assayed by mapping, using X-ray fluorescence analysis. The major metal components measured in the filter that collected the inhaled diesel exhaust particles were calcium, copper, iron, nickel and zinc. Our studies reveal an increase in the amount of nano-sized particles in the glomerular layer as well as in the neurons in the olfactory epithelium. Higher levels of nickel and iron were found in the olfactory epithelium's lamina propria mucosae in comparison to that in the control group. Higher levels of iron also were observed in the glomerular layer. Our studies do not clarify the specifics of metal adhesion and detachment. This remains to be one of the key issues requiring further clarification.