Surfactant Self-Assembly

Abstract

Summary In general, there are three types of behavior of a surfactant or a polar lipid as the concentration is varied. The three cases are characterized by different ranges of existence of the isotropic solution phase. Linear growth of micelles is the strongly dominating type of growth. Disc-like or plate-like structures may also form, but these micelles are quite small and exist only in a narrow range of conditions (concentration, etc.). A very striking feature of gemini surfactants is that they start to form micelles at a concentration more than one order of magnitude lower than that of the corresponding “monomeric” surfactant. In a phase diagram one can read how many phases are formed, which the phases are and what the compositions of the phases are. The determination of a complete phase diagram involves considerable work and skill, and strongly increases in difficulty as the number of components increases.