Electrostatic effects in films stabilised by non-ionic surfactants.
The disjoining pressure Pi of films of aqueous octyl-beta-glucoside (beta-C(8)G(1)) solutions with and without salt was measured as a function of the film thickness by means of a thin film pressure balance. The analysis of the experiments confirms the presence of an electrostatic double layer which dominates the long-range interactions as found in previous experiments with other non-ionic surfactants in the presence of added salt. In the absence of salt, we find a local ion concentration much higher than that of the residual ionic impurities present in the bulk solution.
Márquez-Beltrán
César
C
Laboratoire de Physique des Solides, Bâtiment 510, Université Paris-Sud, 91405 Orsay cedex, France.
Langevin
Dominique
D