POLYMER SURFACTANT FILMS AT THE AIR-WATER-INTERFACE .1. SURFACE PRESSURE, ELLIPSOMETRY, AND MICROSCOPIC STUDIES

Mixed films formed by an insoluble polymer, poly(dimethylsiloxane) (PD MS), placed on the surface of aqueous solutions of two different solub le surfactants are studied by a variety of different methods: surface tension isotherms, ellipsometry complemented by the neutron reflectivi ty experiments presented in part 2, and direct observations of the sur face via the Brewster angle microscope. A vertical separation into sup erimposing surfactant and polymer layers is exhibited, with mixing bet ween the layers depending on the surfactant. On one but not the other of the surfactant solutions studied, a lateral separation of the polym er monolayer is also observed, into domains similar to those previousl y observed on pure water. The collapse of the monolayer into a three-d imensional state with increasing polymer concentration occurs more smo othly than on water.