Theory of Surface Tension in Liquid Mixtures

Abstract

Abstract Equations determining the density profiles of a multicomponent liquid are first given in terms of the partial direct correlation functions in the presence of the surface. The fluctuation theory of surface tension is also generalized to liquid mixtures. The density gradient procedure simplifies the above problem to knowledge of direct correlation functions in the bulk mixture. For the binary case, the density profile equations are then usefully written in terms of number-concentration correlation functions. The total density and surface segregation profiles are finally considered in a simplified model by utilizing the theory of conformal solutions. Such a model, though limited in practice, should apply, for example, to the Na-K alloy system.