Adsorptiekinetiek aan het lucht-water grensvlak. (Dutch text);.

摘要

Diffusion/convection theory for adsorption at fluid interfaces was extended for kinetic- and mixed controlled adsorption kinetics.; The adsorption kinetics at the air-water interface was investigated for about 20 surfactants, and it was shown that for a number of surfactants the adsorption kinetics is influenced by an 'adsorption barrier'. The adsorption and desorption velocity constants were measured and the experimental data were matched by the theoretical model.; It seems that, for homologous series, the adsorption velocity constant increases with increasing chain length, while the desorption velocity constant remains unchanged. The influence of molecular structure and functional groups is only important insofar as the solubility of the surfactant is changed. The adsorption barrier seems to be a pure entropy phenomenon.; Experimental data seem to show that also the adsorption kinetics of macromolecules at the air-water interface in the first stage of the adsorption process is influenced by an adsorption barrier.; A start was made of an investigation of the adsorption kinetics at liquid-liquid interfaces. A new experimental technique was introduced: the dynamic drop-volume technique. It seems that the adsorption kinetics from the water phase to the oil phase is analogous with the adsorption at the air water interface. Adsorption from the oil phase to the water phase shows long time effects which cannot be explained by diffusion as sole relaxation mechanism.