Phase Behaviour and Characterization of Various Microdomains in Pseudo-Ternary Triton X-100 + 1-Hexanol/Aqueous Electrolyte/Oil Systems

Several microemulsion microstructures have been identified in the aqueous phase region of Triton X-100/1-hexanol/aqueous electrolyte/oil systems by conductivity, viscosity, and quasi-elastic light scattering measurements. Effects of various parameters such as bulk oil, electrolyte concentration and temperature on the microstructures of the above systems have been investigated. The phase diagram with cylcohexane has been found to be a combination of large one phase isotropic region and a small mesophase of liquid crystalline gel. In the dodecane system, the addition of sodium chloride has made the mesophase disappear with an extension of the one phase region towards the water axis. The single phase isotropic region consisted of oil-in-water microemulsion and water-in-oil microemulsion separated by a bicontinuous microemulsion. In the upper high surfactant - co-surfactant concentration region, the system seemed to be consisting of small hydrated reverse aggregate of Triton X - 100 dispersed in hexanol and oil medium. Optimum salinity of the above systems had a major dependence on the amount of electrolyte added and a minor dependence on temperature.