Silver Colloid Nanoparticles: Synthesis ..

In summary, we have demonstrated a simple, clean, effective, economical, nontoxic, and environment friendly technique for the synthesis of colloidal silver nanoparticle by using starch as reducing and stabilizing agent under sonication. Sonochemical reduction route demonstrates a remarkable potential for fabricating desired particle size colloidal silver nanoparticles. Absorption spectra confirm the presence of surface plasmon resonance at 420 and 440nm, characteristic of Ag-Nps. A diverse range of pH was used to standardize the reaction at room temperature. In addition, the use of sonication for synthesis of Ag-Nps is more environmentally friendly and safer than other synthetic methodology. Starched Ag-NPs showed efficient catalytic activity for the synthesis of 2-aryl benzimidazole.

Synthesis of Silver Colloids: Experiment and Computational Model

A one-step simple synthesis of silver colloid nanoparticles with controllable sizes is presented

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 .

Silver Colloid Nanoparticles: Synthesis, Characterization, and Their Antibacterial Activity
This paper aims to review different synthesis routes of silver nanoparticles and their ..

Colloidal synthesis synonyms, ..

The pH of 10mL, 1mM silver nitrate was adjusted to 5.5, 7, 8, 8.5, 9, 10, and 11 using dilute sodium hydroxide (0.1 N); 25mg starch was added with continuous stirring. After complete addition, the reaction was allowed to proceed under sonication for 20mins whereby silver colloid was formed (). It is important to note that we performed the reaction up to pH 11 because the very high alkaline condition of the medium may lead to weakening of the association (H-bonding) even for the starch matrix and thereby diminishing its templating potential to support small sized nanoparticles []. A further increase in the basicity of the medium may be resulting in a red shift of the peak position. shows the respective graph of particle size (DLS) of the silver colloid obtained using starch as reducing and stabilizing agent at different pHs. The results reveal a number of observations which may be summarized as follows: (a) increasing the pH of the solution from 5.5 to 8.0 is accompanied by increase of particle size and pH of the solution from 8.0 to 11.0 abrupt decrease of particle size; (b) the smallest particle size was observed at pH 11 and the size of Ag-Nps decreases with time from 4hrs to 22 days (0.0857 to 0.0411μm); (c) particle size continuously increases with time from pH 5.5 to 8.5 in the reaction mixture; (d) the particle size decreases from 12hrs to 9 days and then increases from 9 days to 22 days at pH 9 and 10; (e) when the pH 11 is targeted, the size becomes smaller and could be assigned to the Ag-Nps.

List of True Colloidal Silver Products Click here for a partial list of true silver colloid ..

PubMed - National Center for Biotechnology Information

XRD measurement: The silver nanoparticle solution thus obtained was purified by repeated centrifugation at 5000 rpm for 20 min followed by redispersion of the pellet of silver nanoparticles into 10 mL of deionized water. After freeze drying of the purified silver particles, the structure and composition were analyzed by XRD and SEM. The dried mixture of silver nanoparticles was collected for the determination of size of Ag nanoparticles. Pro X-ray diffract meter operated at a voltage of 40 kV and a current of 30 mA with Cu Kα radiation in a θ-2θ configuration. The crystallite domain size was calculated from the width of the XRD peaks, assuming that they are free from non-uniform strains, using the Scherrer formula:

Title: Silver halide colloid precursors for the synthesis of monolayer-protected clusters: Authors: Lahtinen, RM × Mertens, Stijn East, E Kiely, CJ

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Synthesis of Ag NPs using Tri Sodium Citrate (TSC): This process uses trisodium citrate as a reducing agent which helps in the formation of silver nanoparticles 0.084 gm of silver nitrate AgNO3 was weighed and then added to 500 ml of boiling distilled water. The solution was mixed well and then continued to boil. Now a 1% solution of trisodium citrate was prepared. This was done by dissolving 1 gm of TSC in 100 ml of distilled water. After this 5ml of 1% TSC was added drop wise slowly by using a pipette. Then the solution was kept to heating only until up to 2 hrs after which a reddish green solution is formed which resemble silver nanoparticles as in research papers. The solution was allowed to cool at room temperature and then sent for characterization