Prediction of internal structure and properties in fluid model interfaces of binary and ternary liquid mixtures

In the application of the density functional theory to liquid-liquid interfaces, we analyzed the influence of different approximations within the theory on the calculation of interfacial structure and thermodynamic potential properties. Especially the use of a weighed density approximation allows us to take short-range local ordering into account. It results in oscillating partial densities or concentration profiles and it yields a highly structured grand canonical potential density across the interface which demonstrates how energetically inhomogeneous a liquid interface is. For a ternary model system, the interfacial tension is calculated, capillary wave contributions are added and their influence is discussed.