Ek. Mann et al., POLYMER SURFACTANT FILMS AT THE AIR-WATER-INTERFACE .1. SURFACE PRESSURE, ELLIPSOMETRY, AND MICROSCOPIC STUDIES, Macromolecules, 26(25), 1993, pp. 7037-7045
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.