A SANS study of microemulsions in the pseudoternary aerosol OT/cyclohexane/aqueous AgNO3 solution and formation of silver nanoparticles in microemulsions

This article deals with an investigation on the phase behavior of the pseudotemary AOT/cyclohexane/ aqueous 0.2 M AgNO3 solution and features of its water-in-oil (W/O) microemulsions (MEs). The sizes and structures indicative of water pools in the microemulsions were determined by small-angle neutron scattering (SANS). SANS spectra indicated that water pools of spheres with sizes 4 similar to 10 nm and of cylinders with lengths of 25 similar to 30 nm were formed at four different compositions inside the microemulsion region. Silver nanoparticles were prepared with the microemulsions and identified by the peaks at a wavelength of 400 nm in their UV/Vis absorption spectra. TEM micrographs showed that the silver nanoparticles were spherical and rod-like, depending on the compositions of the microemulsions and reflecting the sizes and shapes of the water pools.