Effect of the adsorption component of the disjoining pressure on foam film drainage

TL;DR

This paper investigates how the adsorption component of disjoining pressure influences foam film drainage, explaining discrepancies between experiments and classical models by incorporating adsorption effects.

Contribution

It introduces the significance of adsorption component of disjoining pressure in foam film drainage and quantifies it through experimental data fitting.

Findings

Adsorption component reduces film thinning velocity.

Inclusion of adsorption component corrects equilibrium film thickness.

Experimental data fit reveals slight repulsive disjoining pressure contribution.

Abstract

The present work is trying to explain a discrepancy between experimental observations of the drainage of foam films from aqueous solutions of sodium dodecyl sulfate (SDS) and the theoretical DLVO-accomplished Reynolds model. It is shown that, due to overlap of the film adsorption layers, an adsorption component of the disjoining pressure is important for this system. The pre-exponential factor of the adsorption component was obtained by fitting the experimental drainage curves. It corresponds to a slight repulsion, which reduces not only the thinning velocity as observed experimentally but corrects also the film equilibrium thickness.