STABILIZATION OF AQUEOUS FOAM BY HYDROSOLUBLE POLYMERS .2. ROLE OF POLYMER SURFACTANT INTERACTIONS

We study the incorporation of hydrosoluble polymers in soap films and use different polymer/surfactant pairs in order to vary the interactions. Soap films are entrained on a vertical frame, and their thickness is measured by light reflectivity. This study shows that the mixed films have different hydrodynamic properties depending on the interactions between the polymer and the surfactant. As long as the polymer/surfactant interactions remain weak, the formation of mixed films, like that of pure surfactant films, obeys the Frankel law (the thickness increases with the entrainment velocity to the power 2/3); consistently, these films have similar kinetics of drainage. On the other hand, with strong associative polymer/surfactant pairs, the kinetics is accelerated. When the drainage is complete, the films become common black films, whose thicknesses are generally independent of the presence of polymer in the reservoir.