Chapter 15. Association Colloids: Micelles, Vesicles, and Membranes

Summary

Chapter 15 discusses the class of colloids commonly referred to as association colloids—reversible aggregations formed by thermodynamically driven process of molecular interactions. The chapter addresses the nature, formations and characteristics of surfactant micelles, vesicles, and membranes. Beginning with an introduction to the question of surfactant solubility, it describes the basic nature of micelles, the energietics of their formation, and classic theories pertaining to the size and constitution of micelles. It also introduces the concept of surfactant molecular geometry as the controlling factor in determining the existence, size, shape, and overall nature of the micelles formed by a given surfactant. The roles of the chemical natures of the molecular components of the surfactant molecule are discussed as well as the effects of additives (ionic species and nonionic solutes) and temperature on micelle formation. Mixed surfactant systems and nonaqueous micellar systems are briefly discussed. The formation and characteristics of vesicle and membrane aggregations of surfactants is briefly discussed, especially with relation to the molecular geometry of the aggregating species.