This study investigates water-in-oil microemulsion stabilised by Aerosol OT (AOT) dispersed in n-decane at water/AOT molar ratio of 6.7. The collective diffusion coefficient of microemulsion and microemulsion/tetrabutylammonium chloride (TBAC) systems was investigated by photon correlation spectroscopy (PCS). In the systems at the constant water/AOT concentration, the collective diffusion decreases with the reduction of oil concentration. Furthermore, PCS experiment revealed that collective diffusion coefficient of AOT/H2O/n-decane microemulsions increased with TBAC added to the microemulsion. We also studied the structural information of pure and salt-mixed AOT microemulsion by small-angle X-ray scattering technique. The structural investigation of our samples shows cylindrical to spherical transition with the reduction of oil concentration.

Keywords