The Formation and Characteristic of Middle Phase Microemulsion——Ⅲ.Clothespin Surfactant

The experiments show that the middle phase microemulsions can form in di（2-ethylhexyl） sulfosuccinate （AOT） / alcohol / octane / brine systems containing highly purified surfactant. These systems have been investigated using salinity scanning and interfacial tension methods.
The formation and characteristic of middle phase microemulsion are affected markedly by the concentration of AOT. The range studied was from 1.0% to 7.0%. Salinity and the kind as well as the concentration of alcohol were also found to have an effect. Alcohols studied include ethanol, n-propanol, n-butanol and n-pentanol, which concentration of the alcohols used was from 1.0% to 7.0%. Some differences between the system with AOT and AS （sodium dodcyl sulfonate） are also disscussed. Some rules have been found and theoretical discussions have been attempted. This is believed to be practically important in formulating detergents and cosmetics.