Free energy density functionals for non-uniform classical fluids

Abstract

Recent applications of the density functional formalism to the study of the structure and thermodynamics of non-uniform classical fluids are briefly quoted. The problems considered involve fluid-fluid interfaces in pure and multicomponent fluids, fluid to-wall density profiles, solidification, nucleation, spinodal decomposition and interface motions. It is shown that the variational principle for the grand potential yields the potential distribution theory for the equilibrium density, and thus we exhibit the manner in which these two theoretical frameworks to study non-uniform systems are related. Also, we present a derivation of the exact form that the grand potential functional takes for a system of hard rods. Then, we consider attractive interactions in meanfield approximation from which the functional that corresponds to the Van der Waals fluid is obtained.