Kinetics of non-ionic surfactant adsorption at a fluid-fluid interface from a micellar solution

TL;DR

This paper presents a theoretical model for non-ionic surfactant adsorption kinetics at fluid interfaces, highlighting the influence of micelle relaxation on diffusion and adsorption regimes, offering new insights into dynamic surface tension behavior.

Contribution

The study introduces a model that incorporates micelle relaxation effects, providing a novel interpretation of surfactant adsorption dynamics from micellar solutions.

Findings

Adsorption can be diffusion-limited or kinetically limited.

Micelle relaxation time determines the adsorption regime.

New interpretation of dynamic surface tension observed in experiments.

Abstract

The kinetics of non-ionic surfactant adsorption at a fluid-fluid interface from a micellar solution is considered theoretically. Our model takes into account the effect of micelle relaxation on the diffusion of the free surfactant molecules. It is shown that non-ionic surfactants undergo either a diffusion or a kinetically limited adsorption according to the characteristic relaxation time of the micelles. This gives a new interpretation for the observed dynamical surface tension of micellar solutions.