Properties of a Mixed Micellar System of Sodium Dodecyl Sulfate and Octylglucoside.

Properties of a binary mixed surfactant system of a nonionic surfactant, octylglucoside, and an anionic one, sodium dodecyl sulfate, were investigated by measurement of the surface tension of their aqueous solutions containing 20, 75, and 150 mM sodium chloride. Changes in the critical micelle concentration with the composition of the two surfactants thus determined were analyzed according to the conventional regular solution theory for mixed micelles as well as with reference to Maeda's formulation for ionic/nonionic mixed micelles (H. Maeda, J. Colloid Interface Sci. 172, 98 (1995)). For the three salt concentrations, the properties of the mixed micellar system were found to be well described by the above theories, and the parameters in Maeda's formulation, B1 and B2, which are equivalent to the interaction parameter in the conventional theory of regular solution approach were determined. The effect of salt concentration on the properties of the mixed micellar system is discussed. Copyright 1997 Academic Press. Copyright 1997Academic Press