Correlation in the properties of aqueous single films and foam containing a nonionic surfactant and organic/inorganic electrolytes

Correlation of the behavior of foam from aqueous solutions of C10E8 + TPeAB mixtures with the properties of the single foam films is sought through a theoretical analysis based on experimental data. The state in the adsorption layer on the air/solution interface has been determined from the surface tension experimental data by applying the Frumkin adsorption isotherm for mixed surfactants. Diverse parameters of the adsorption layer have been calculated. Values of the surface potential, estimated from the electrostatic disjoining pressure in the films, are found to be in good agreement with those calculated through the Grahame equation for the air/water interface. The energy of interaction (attraction) in the mixed adsorption layers is determined. The behavior of a foam body produced from solutions of the same composition, is also investigated in two independent ways using the stationary foam column and the foam life-time (decay rate) methods. Both techniques gave similar results with respect to foam stability. (C) 2003 Elsevier Science (USA). All rights reserved.