Mixing of oils with surfactant monolayers

Abstract

In systems containing oil, water and surfactant, the penetration of oil into the chain region of the surfactant monolayer governs, in part, the system behaviour. For example, the limiting area per molecule for Aerosol-OT in saturated monolayers at the oil-water interface depends markedly on the alkane chain length. This, and other results, are discussed in connection with the occurrence of low oil-water interfacial tensions and microemulsion inversion from Winsor I-III-II systems. We also present new data for the effects of aliphatic remove oils on the cloud points of micellar solutions of nonionic surfactants, and discuss the probable locus of oil solubilisation. In connection with an attempt to determine alkane penetration into surfactant monolayers quantitatively, we report preliminary data for mixed films of oil and cationic surfactant at the air-water interface.