Interfacial hydrodynamics: A microscopic approach

Abstract

Linearized hydrodynamic equations for a nonuniform anisotropic fluid are obtained from the exact Mori–Zwanzig equations for the conserved densities. In the particular case of a two-phase system with a planar equilibrium interface, these equations can be reduced to the ordinary hydrodynamic equations inside each bulk phase and to surface hydrodynamic equations for the interfacial layer. Surface transport coefficients and surface thermodynamic parameters are hereby obtained as Gibbs surface excess values. All the known phenomenological equations can be recovered by suitable approximations. Various correction terms to the phenomenological results, including Laplace’s formula, are found.