Kinetic Study of the Diffusion and Adsorption of Fatty Acids at the Benzene-Water Interface.

Dynamic interfacial tension measurements were used to investigate the kinetics of the diffusion/adsorption of surfactant molecules at the benzene-water interface. Measurements were performed on stearic acid and capric acid by the pendant drop method at both benzene-acidic aqueous and benzene-basic aqueous interfaces. The process takes place by different mechanisms in the acidic and basic aqueous phases.

Surface complexes of xanthophyll films with transition metal ions.

Compression isotherms of astaxanthin (AX; 3,3'-dihydroxy-4,4'-dioxo-beta-carotene) monolayers, recorded at the air/water interface show, on the one hand, the collapse pressure to depend on the subphase pH, indicating the ionisation of AX at high pH values, and on the other hand, the subphase Co2+ ions to have a condensing effect upon the monolayer and to entail the increase of its collapse pressure. The latter effects are assigned to surface complex formation. The interfacial tension at the benzene/water interface (the benzene phase containing AX, the water phase Co2+ ions) exhibit a maximum at a molar ratio AX: Co of about 3.