FOAM FILMS AND SURFACE FORCE STUDIES OF AQUEOUS-SOLUTIONS OF OCTYL-BETA-GLUCOSIDE

The interactions at the air/liquid and the liquid/solid interface have been studied for octyl-beta-glucoside. With the thin film balance the thickness of the equilibrium liquid films is determined as a function of surfactant concentration, inert salt concentration and pH. At high surfactant concentration and/or at low pH black films, about 4.6 nm t hick, are formed. The stabilizing forces in the black films are relate d to the interactions within and between the layers. The forces acting between octyl-beta-glucoside surfactant layers adsorbed on hydrophobi zed mica were investigated with the interferometric type surface force apparatus. The forces measured between the sugar head-groups were dim ethylamine oxide and monoglycerides. However, considerably more long-r ange repulsions are observed between surfactants with oligoethylene ox ide head-groups.