Interfaces Between Two Fluids

The three types of dispersions, emulsions, microemulsions, and foams, are all stabilized by adsorbed layers of surface-active substances. The role of these layers will be discussed at length, because they are central in the behavior of dispersions. Adsorption layers make the link between the different dispersions; they are at the origin of numerous similarities encountered between them. The basic knowledge will be recalled in this chapter, starting with the simplest case of interfaces between pure fluids. More details can be found in classical textbooks (Adamson and Gast 1997; Evans and Wennerstrom 1999; de Gennes et al. 2004).