Adsorption of surfactants and proteins at fluid interfaces

This review presents some new equations of state and adsorption isotherms which describe mixed monolayers of surfactants possessing different molar area values, monolayers which comprise surfactants and proteins capable of reorientation or reconformation. For systems allowing reorientation and aggregation, the effect of self-regulation of the surface layer composition caused by surface pressure is considered. This effect is especially pronounced in protein adsorption layers, where not only the composition, but also the thickness of the adsorption layer depends on surface pressure. This principle was first proposed by Paul Joos for describing surface layers. The results of the proposed models have a direct impact on dynamic surface phenomena. The rate of adsorption for a diffusion-controlled mechanism depends on molecular reorientation or aggregation processes within the surface layer. For protein surface layers mainly conformational changes at the surface determine the rate of adsorption/desorption and other dynamic and mechanical properties of surface layers. (C) 1998 Elsevier Science B.V. All rights reserved.