Rigorous interface properties for the van der Waals fluid mixture

Abstract

A statistical mechanical treatment for the van der Waals fluid mixture is developed, based on Widom’s potential‐distribution theory for nonuniform fluids. For the specific choice of Kac pair interactions, in the van der Waals limit, a set of coupled second‐order differential equations determine the density profiles. The solution of these equations and the determination of the interfacial tension are discussed in terms of a mechanical analogy.