Showing 6 results for Silver
M. Karbasi, A. Saidi, and Gh. Ariyanpour,
Volume 26, Issue 1 (7-2007)
Abstract
Production of nickel-silver by mechanical alloying was investigated. Effects of parameters such as milling duration, ball to powder weight ratio, and chemical composition on mechanical alloying process, and alloy's color and microstructure were studied. The milled powders were characterized, using XRD and SEM. Results showed that nickel-silvers could be produced by mechanical alloying in a wide range of compositions. Alloyed powder with a bright silvery contrast and less than 15 nm grain size could be obtained by optimization of milling parameters. Zinc content of the powder mixture had a significant effect on the minimum alloying time. Ball to powder ratio up to 25 also reduced minimum alloying time but it had no significant effect above this value.
M.r. Saeri, M. Azizi1, R. Amooaghaie,
Volume 34, Issue 4 (3-2016)
Abstract
Bio-inspired silver nanoparticles were synthesized with the aid of a novel method, using leaves of the plant Nigella sativa. After drying the leaves in air, they were first sweltered in boiling distilled water and the liquid was filtered subsequently. The result was the brothused to reduce solutions including various concentrations of silver nitrate in a proper amount of pH. The displayed UV–visible spectra identified formation of silver nanoparticles whenever the colorless initial acclimated mixture turned brown. The centrifuged powder samples were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (FESEM) and energy dispersive X-ray diffraction analysis (EDX) methods. The results clearly revealed that the final particles of precipitated powder are high purity agglomerates of silver nanoparticles. Besides, the effects of various amounts of the silver salt on particle size of nano silver were studied, using a particle size analyzer. FTIR results also indicated the role of different functional groups in the synthetic process.
S. Yazdkhasti, A. Monshi, A. Doostmohammadi,
Volume 34, Issue 4 (3-2016)
Abstract
With various features such as strong oxidation, biocompatibility and acceptable mechanical properties, titanium dioxide (TiO2) is among the materials that are frequently used in biological and medical applications. Nowadays, with the aim of increasing the efficiency of titanium dioxide and practical use of this material, doping it with elements such as silver, zinc and iron has been favored. In this study, Ag-TiO2 and ZnO-TiO2 nanoparticles were prepared by the sol–gel method and were evaluated and compared.In order to identify the present phases in the structure, X-ray diffraction analysis was used. Also for the characterization of the nanoparticles, Ultraviolet–visible spectroscopy (UV-Vis), Energy-dispersive X-ray spectroscopy (EDS), Field Emission Scanning Electron Microscope (FESEM) and Zeta Potential were used. Inaddition, the antibacterial activities of nanoparticles were investigated and compared. The results showed that sol-gel method could successfully produce nanoparticles of Ag-TiO2 and ZnO-TiO2 with the expected combination. The investigation of antibacterial properties of these particles revealed that at lower inhibitory concentrations, Ag-TiO2 composition has a higher antibacterial activity than ZnO-TiO2 one.
P. Mouchani, R. Sarraf Mamoori, N. Riahi Noori,
Volume 35, Issue 4 (2-2017)
Abstract
In this study, the parameters affecting the synthesis of silver nanoparticles were optimized by green chemical reduction method to make a conductive pattern. The raw materials used in this study, include silver nitrate as a source of
silver ions, polyvinylpyrrolidone as surface stabilizer, and glucose as the reducing agent. Effective parameters were investigated
by Taguchi statistical design, to determine the optimum conditions and achieve the smallest average particle size. Silver nanoparticles were characterized by X-ray diffraction and field emission scanning electron microscopy. The smallest particle size can be applied by solution adding rate of 0.1 ml/min, temperature 90 °C, weight ratio of glucose to silver nitrate 3 g/g and weight ratio of Polyvinylpyrrolidone to silver nitrate 3.2 g/g. According to.our expectation 20 nm silver nanoparticles were obtained in this condition. FE-SEM confirmed the above results and showed nanoparticles with a size of 25 nm. Finally, A conductive pattern was printed on a glass substrate with synthesized powder. The electrical resistance of the printed pattern was 0.088× 10 -4 Ω.cm.
D. Haghshenas, A. Amirjani,
Volume 36, Issue 4 (3-2018)
Abstract
In this study, null and one-dimensional nanoparticles and nanostructures of Ag and Ag-Cu were synthesized using polyol method. In order to prepare different nanostructures with the same synthesis route, thermodynamics and kinetic conditions of the system were manipulated. In the thermodynamics approach, the nanostructures with the minimum surface energy were obtained as the final product, while in kinetic approach, the nanostructures with the lower activation energy were formed. By using these appraoches, Ag and Ag-Cu spherical and cubical nanostructures were produced in the size range of 90-100 nm. Also, by manipulating the kinetic conditions of the system, silver nanowires with the diameters in the range of 100-200 nm and the length of several microns were obtained successfully. The effect of Cu ions (Cu2+) on aspect ratio of the synthesized silver nanowires by polyol method was evaluated.
R. Karimi-Chaleshtori, M. R. Saeri, A. Doostmohammadi ,
Volume 40, Issue 1 (5-2021)
Abstract
Silver nanowires (AgNWs) are considered as one-dimensional nanostructures, which have received much attention due to their nanoscale size, high aspect ratio, high electrical and thermal conductivity, optical transparency and high mechanical stability. Preparation of AgNWs by polyol process is remarkably sensitive to the interactions between synthesis parameters. In this study, the effect of the simultaneous change of four synthetic parameters, namely the reaction temperature, the molecular weight of polyvinylpyrrolidone (PVP) stabilizer, the amount of sodium chloride, as well as, the solution mixing rate by the polyol process was reported. The results of field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) confirmed that the synthesized AgNWs were below 100 nm. X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) analysis, as well as, Fourier transform infrared spectroscopy (FT-IR) confirmed that the formed AgNWs were free of impurities. It was also found that temperature, molecular weight of PVP, salt concentration and solution mixing rate caused a significant change in the morphology of AgNWs. More importantly, a strong interaction was created in the preparation process of AgNWs by adjusting the parameters.
