AMPHIPHILIC ASSOCIATION STRUCTURES AND THIN-FILMS

The article discusses two generally accepted phenomena in colloid chemistry: the variation of van der Waals' forces during flocculation and coalescence in emulsions and the importance of a monomolecular surface layer of surfactant for the stability of foams. It is shown that the opinion that the van der Waals force is monotonously increasing during flocculation and coalescence of emulsion droplets is not generally true. The force may be a discontinuous function of film thickness. It is also demonstrated that stable foams may be obtained in solvents in which the added surfactant lacks surface activity. The common stabilizer, a surfactant monolayer, is replaced by a separate phase.