Direct measurement of disjoining pressure in black foam films II. Films from nonionic surfactants

Direct measurement of interaction forces in free thin liquid films stabilized with phosphatidylcholine

“…Experiments with microscopic free foam films stabilized with ionic and non-ionic surfactants have led recently to elucidation of important aspects of the applicability of this theory. It has been shown that the experimental data for films stabilized with non-ionic surfactants are in good agreement with the theoretical predictions for film thicknesses higher than 20-30 nm (Kolarov et al 1989), while for films stabilized with anionic surfactants deviations from the theory have been observed for film thicknesses below about 50 nm (Exerowa et al 1987a). A review of the most important theoretical and experimental results for the common black to Newton film transition and the stability of the 204 Newton films was given by Exerowa and Kashchiev (1986).…”

“…Horizontal equilibrium foam films with a radius of about 0.01 em were formed in the center of a doubly concave drop of the SUV suspension placed in the glass tube drop holder of the measuring cell as described in detail elsewhere (e.g. Exerowa et al 1979Exerowa et al , 1987aKolarov et al 1989). The inner space of the measuring cell is closed so that the aqueous suspension is in equilibrium with its saturated vapour.…”

Interfacial Behavior of n-Decyl-β-D-maltopyranoside on Hydrophobic Interfaces and the Effect of Small Amounts of Surface-Active Impurities

“…It is experimentally established that nonionic surfactants, both ethoxylated alcohols and sugar-based surfactants, form common black films that are electrostatically stabilized (31,32). Further, also "pure" air-water interfaces are charged (33).…”

Hydrophobic Forces in Thin Water Films Stabilized by Dodecylammonium Chloride

“…In general, the theory has been useful at relatively high surfactant concentrations. Kolarov et al (2) showed that the disjoining pressure isotherms obtained in the presence of nonionic surfactants and in an uncharged phospholipid can be predicted by the DLVO theory; however, the pressures measured in the presence of ionic surfactants are considerably larger than predicted (3). More recently, Bergeron et al (4) measured disjoining pressure isotherms with octyl ␤-glucoside, which are in good agreement with the theory.…”

“…Equilibrium thicknesses of free water films were measured using a TFB of Scheludko-Exerowa type (1,2,21). Figure 1 shows the experimental set-up.…”