CALORIMETRIC INVESTIGATION ON THE FORMATION OF GOLD NANOPARTICLES IN WATER AOT/N-HEPTANE MICROEMULSIONS/

The formation enthalpy of gold nanoparticles in water/sodium bis(2-eth ylhexyl) sulfosuccinate (AOT)/n-heptane microemulsions as a function o f the water/AOT molar ratio R(R = [water]/[AOT]) was measured by a cal orimetric technique at various AOT concentrations. The size of An nano particles was determined by transmission electron microscopy. The resu lts indicate that both the energetic state and the dimensions of the g old nanoparticles are influenced by the radius and the concentration o f the reversed AOT micelles. Analysis of the decay of the calorimetric signal provides evidence of some interesting features of the growing process of the Au nanoparticles in water/AOT/n-heptane microemulsions.