Lecithin organogel: A micellar system with unique properties

Lecithin self-assembles in nonaqueous media into reversed giant cylindrical micelles when small amounts of water, glycerol or formamide are added. The micellar aggregates, much like the polymer molecules, overlap, interpenetrate, entangle, thus forming a temporal three-dimensional network that brings about viscoelastic properties. For this reason, the micellar system is in a jelly-like state. This review article considers key results on the phase behavior, molecular interactions, properties, structure and dynamics of the lecithin organogels as well as current models for the polymer-like micelles. Much attention is given to rheological behavior. The effects of a shear flow, electric field and added surfactants, that cause a significant change in the structure and properties of the micellar system, are also discussed.