DEMIXING IN TERNARY MIXED MICELLES

Micellar demixing yielding conjugate micellar phases that coexist in a n aqueous solution is known for a very few surfactant systems even tho ugh the presence of two distinct types of micelles in solution has pra ctical application. Here, on the basis of a pseudophase regular soluti on model for surfactant chemical potentials, we predict micellar demis ing to be widely prevalent in ternary surfactant mixtures that contain anionic, cationic, and nonionic surfactants. While demixing of micell es in these ternary systems has not previously been reported, the pred iction is confirmed here on the basis of surface tension measurements. (C) 1998 Academic Press.