Studies on absorption spectra of uniform gold nanoparticles prepared in Triton X-100 reverse micelles

A procedure for preparation of uniform gold nanoparticles in the ternary Triton X-100/water/cyclohexane system in the presence of sodium sulfite is suggested. The formation and stabilization of nanoparticles in Triton X-100-based reverse micelles in the above ternary system and in the quaternary system (additionally containing n-hexanol) have been explored. The mechanism for formation of Au(0) and growth of gold clusters was found to depend on the initial concentration of HAuCl4 and Na2SO3. The mean size of nanoparticles formed in reverse micelles in the ternary system was markedly smaller (less 5 nm) than of those formed in the quaternary system (from several to dozens nanometers).