Amphiphilic molecules: Small and large

Abstract

Amphiphilic molecules have an affinity for two different types of environments. This dual affiliation is built into the molecules by the covalent joining of parts of different chemical character and solution properties. Large amphiphilic molecules represent a new frontier in the field of surfactant science and technology. Their macromolecular nature affords a range of architectures, length scales, time scales, and levels of interactions much wider than those offered by small amphiphilic molecules. At the same time, such diversity poses great challenges in the characterization and the understanding of the solution and surface properties of large amphiphiles. The evolution in self-assembly properties from small to large amphiphiles is outlined in this chapter, and the two classes of molecules are placed in perspective. The importance of self-assembly studies thus becomes apparent. In addition to the numerous studies on small amphiphilic molecules already published, studies on large amphiphiles are likely to become more prominent in the years to come and will significantly enhance the fundamental understanding and ability to manipulate self-assembly for the common good. Large amphiphiles, such as block copolymers, are very flexible in attaining a great variety of microstructures in the absence or in the presence of solvents or other additives. Furthermore, their macromolecular nature allows access to a wide range of length scales and time scales. Amphiphilic block copolymers thus have a potential of great contributions to diverse applications, such as synthesis of functional nanoporous materials or formulations of coatings, paints, pharmaceuticals, and personal care products.