Preparation of silver nanoparticles in water-in-oil AOT reverse micelles

Colloidal silver nanoparticles were synthesized in AOT microemulsions. The effects of the precursors' concentration and the molar ratios of water to AOT on the particle size and size distribution were investigated. UV–vis spectra showed that the Ag+4 intermediates formed at low N2H4 concentration. TEM micrographs confirmed that the silver nanoparticles are all spherical with mean diameters in the range 2–5 nm and have a narrow size distribution. Not only the particle size but also the size distribution was increasing with the W value. The silver colloid has favorable stability and can be preserved for a long time without precipitation.

The silver nanoparticles were synthesized by AOT–dodecane–H2O microemulsion. Transmission electron microscopy (TEM) and UV–vis spectroscopy were used to characterize the resultant silver colloid. The Ag+4 intermediates formed at early stages of the reaction and then the clusters grew or aggregated to form larger nanoparticles. The silver nanoparticles are all spherical with mean diameters in the range 2–5 nm and have a narrow size distribution as well as good stabilization. With the W values increasing, both the average size and the size distribution increased obviously.Figure optionsDownload as PowerPoint slide