Synthesis of Silver Colloids: Experiment and Computational Model
Synthesis of Silver Colloids: Experiment and Computational ..
Highly monodisperse sodium citrate-coated spherical silver nanoparticles (Ag NPs) with controlled sizes ranging from 10 to 200 nm have been synthesized by following a kinetically controlled seeded-growth approach via the reduction of silver nitrate by the combination of two chemical reducing agents: sodium citrate and tannic acid. The use of traces of tannic acid is fundamental in the synthesis of silver seeds, with an unprecedented (nanometric resolution) narrow size distribution that becomes even narrower, by size focusing, during the growth process. The homogeneous growth of Ag seeds is kinetically controlled by adjusting reaction parameters: concentrations of reducing agents, temperature, silver precursor to seed ratio, and pH. This method produces long-term stable aqueous colloidal dispersions of Ag NPs with narrow size distributions, relatively high concentrations (up to 6 × 1012 NPs/mL), and, more important, readily accessible surfaces. This was proved by studying the catalytic properties of as-synthesized Ag NPs using the reduction of Rhodamine B (RhB) by sodium borohydride as a model reaction system. As a result, we show the ability of citrate-stabilized Ag NPs to act as very efficient catalysts for the degradation of RhB while the coating with a polyvinylpyrrolidone (PVP) layer dramatically decreased the reaction rate.
15/12/2017 · Silver Colloid Synthesis in Linear ..
There is growing need to develop eco-friendly and body benign nanoparticle synthesis process without use of toxic chemicals in the synthesis of protocols to avoid adverse effects in biomedical applications (). Nanometal particles, especially silver, have drawn the attention of researchers (). Because of their extensive application in the development of new technologies in the areas of electronics, material sciences and medicine at the nanoscale (). Silver nanoparticles have many applications; for example, they might be used as spectrally selective coatings for solar energy absorption and intercalation material for electrical batteries, as optical receptors, as catalysts in chemical reactions, for biolabelling and as antimicrobials (; ). Many reports well documented on the biogenesis of silver nanoparticles using several plant extracts. The reducing property of different plant constituents may play a critical role in the reduction of Ag+ to silver nanoparticles (). The use of environmentally benign materials like plant leaf extract (), bacteria (), fungi () and enzymes () for the synthesis of silver nanoparticles offers numerous benefits of eco-friendliness and compatibility for pharmaceutical and other biomedical applications as they do not use toxic chemicals for the synthesis protocol. Chemical synthesis methods lead to presence of some toxic chemical absorbed on the surface that may have adverse effect in the medical applications. Green synthesis provides advancement over chemical and physical method as it is cost effective, environment friendly, easily scaled up for large scale synthesis and in this method there is no need to use high pressure, energy, temperature and toxic chemicals. Therefore, the objective of this present study was to synthesis the biologically active nanoparticle from the leaf extract of .