AOT Micelles/Vesicles for Synthesis of Silver Nanoparticles and Micellar Transitions Affected by Nanoparticles

A facile method for the synthesis of silver nanoparticles (Ag NPs) is reported using sodium para-toluene sulphonate (NaPTS) as the reducing agent and AOT micelles and vesicles as capping agents, leading to the development of a system comprising of AOT micelles/vesicles along with Ag NPs. A single component, Na-PTS, has been used to tune the micellar aggregates as well as for the synthesis of Ag NPs. The aggregation behavior of AOT in aqueous Na-PTS has been studied by the method of surface tension and the changes in the morphology of AOT micelles by small angle neutron scattering (SANS) measurements. The synthesis of Ag NPs have also been carried out using common reducing agents such as sodium borohydride and ascorbic acid. SANS measurements have also been performed in the ternary systems of micelles, vesicles and NPs and reveal the formation of fractal structures of the NPs. The ternary systems have been also tested for their antibacterial activity. A very important observation made in the present study is the large decrease in the concentration of salt required to bring about micellar shape transition in the presence of small amounts of NPs.