Mixed cationic and anionic surfactant systems

Because of the strong static attraction between the oppositely charged head groups, the mixed cationic and anionic surfactant systems possess strong synergistic effect and high surface activity, form rich microstructures in aqueous solution and exhibit complicated phase behavior. In this paper, we review recent progress about surface (interface) properties, the preparation and stability of vesicles, the formation and properties of wormlike micelles, and the properties and applications on extraction of aqueous two-phase systems. The theory investigation ( such as pseudophase separation model, thermodynamic cell model, molecular thermodynamics and molecular simulation etc.) and the synthesis of nanomaterial using mixed cationic/anionic surfactant systems as templates are discussed. For the research of the aqueous two-phase systems, some questions need to be solved are indicated.