PHASE-EQUILIBRIA IN AQUEOUS LOW-MOLECULAR CATANIONIC SURFACTANT SYSTEMS

Phase equilibria in systems alkanoic acid-alkylamine-water have been d etermined at 298.2 K. In the system hexanoic acid (A) - hexylamine (B) only one isotropic solution phase is formed. This solution phase is i n equilibrium with almost pure water. The strong A1B1 complex shows ca tanionic surfactant properties as concluded from phase equilibria stud ies in the system A1B1-heptane-water. This system behaves like ordinar y microemulsions. The dominant feature of the phase diagram with ethan oic acid-dodecylamine is the large D phase. In addition there exist a large solution phase, a hexagonal phase and a small cubic I phase.