PROPERTIES OF MIXED MICELLES OF BINARY SURFACTANT COMBINATIONS

The behavior of binary mixtures of aqueous solutions of surfactants ha s been analyzed in the light of (a) Rubingh's approach based on regula r solution theory, (b) the method of excess thermodynamic quantities o f Motomura et al., and (c) the molecular thermodynamic theory of Sarmo ria et al. and Puvvada et al. The binary combinations of anionic-nonio nic, anionic-cationic, anionic-anionic, cationic-cationic, and nonioni c-nonionic surfactant systems including a number of bile salts and sev eral synthetic ionic and nonionic surfactants have been tested. The th eoretical approaches are found to be most successful in describing the mixed micellar properties of anionic-nonionic surfactant solutions. T he anionic-cationic combinations of bile salts and cetyltrimethylammon ium bromide exhibit striking behaviors. The scope and limitations of t he treatments in describing and also predicting the behaviors of diffe rent types of mixed micellar entities have been discussed.