ABSTRACT
The dynamic behavior of air-water interfaces is important in the behavior of detergents, in foaming, in coating flows, in biological membranes, and in lung surfactants. The dynamic adsorption density determines the dynamic surface tension and surface rheology. This chapter focuses on monolayer surface pressure hysteresis, which depends on surface density and rate of change of surface area; monolayer compositional variations caused by surface compression and selective collapse. It also focuses on monolayer density and composition changes occurring during pulsating area changes and resulting from exchanges between the monolayer and extra layers or dispersed particles. The dynamic behavior of single-component spread monolayers – compression rate dependence, hysteresis, collapse – has to be considered carefully in both fundamental thermodynamic monolayer studies and in practical applications. In addition, in mixed monolayers, one should consider the possibilities of squeeze-out effects even below the collapse pressure region.
