Catanionic surfactants: microemulsion formation and solubilization

We review and summarize the three-phase behavior and solubilization of microemulsions with catanionic surfactants. Particular emphasis is placed to the three-phase behavior of mixtures of oil, water and alcohol with mixed surfactants containing one anionic and one cationic surfactant. The effect of salt and catanionic surfactant on the HLB composition and solubilizing capacity of surfactants to form microemulsions is discussed.