Effects of intermicellar exchange rate on the formation of silver nanoparticles in reverse microemulsions of AOT

Abstract

We report the effects of intermicellar exchange rate on absorption spectra and particle size of silver nanoparticles synthesized in reverse micelles of AOT. The silver nanoparticles are prepared by the method of mixing of two microemulsions, one containing the silver nitrate and the other containing sodium borohydride. The intermicellar exchange rate is varied by changing the organic solvent, surfactant (SDS, NP-5, and DTAB), and organic (benzyl alcohol and toluene) additives. The higher intermicellar exchange rate is found to give smaller particle size and blue shift in the absorption spectra. An interesting and potentially useful effect has been observed in that addition of a small amount of a nonionic surfactant significantly reduces the particle size.