Solution behavior of aerosol ot/water/oil system

The phase diagrams of water-cyclohexane containing 5, 10, and 20 wt% sodium 1,2-bis(2-ethylhexyloxycarbonyl)-1-ethanesulfonate (Aerosol OT, AOT) as a function of temperature were studied. There is the water phase in which AOT is dissolved and a large amount of oil is solubilized at higher temperature, and the oil phase in which AOT is dissolved and a large amount of water is solubilized at lower temperature. It is evident from the phase behavior that the hydrophile-lipophile property of AOT is well balanced. Accordingly, the phase diagram and properties of AOT solution are affected rather sensitively by the addition of a small amount of hydrophilic or lipophilic additive or by temperature. Careful elimination of inorganic salts also influences markedly the solution properties of AOT. Thus, the addition or removal of known amounts of inorganic salts, such as Na₂SO₄ is also very important to control the solution properties related to practical applications. In this context phase diagrams of both carefully purified and commercial AOT with or without additives have been determined.