The nature of the liquid-vapour interface and other topics in the statistical mechanics of non-uniform, classical fluids

TLDR

The paper notes other current topics of interest in the study of liquid–vapour interfaces. The study critically reviews recent theoretical work on the microscopic structure and surface tension of the liquid–vapour interface of simple (argon‑like) fluids. The authors analyze pairwise intermolecular correlations and capillary‑wave treatments of the interface, and extend density‑functional theory to generalize linear spinodal‑decomposition theory and study long‑wavelength liquid structure factors. The authors conclude that conventional capillary‑wave theory fails to describe equilibrium interface properties and propose a density‑functional approach that generalizes linear spinodal‑decomposition theory, yielding insights into long‑wavelength liquid structure factors.

Abstract

Abstract Recent theoretical work on the microscopic structure and surface tension of the liquid-vapour interface of simple (argon-like) fluids is critically reviewed. In particular, the form of pairwise intermolecular correlations in the liquid surface and the capillary wave treatment of the interface are examined in some detail. It is argued that conventional capillary wave theory, which leads to divergences in the width of the density profile, is unsatisfactory for describing all the equilibrium aspects of the interface. The density functional formalism which has been developed to study the liquid-vapour interface can also be profitably applied to other problems in the statistical mechanics of non-uniform fluids; here a new generalization of the 'linear' theory of spinodal decomposition is formulated and by considering a 'nearly uniform' fluid, some useful results for the long-wavelength behaviour of the liquid structure factor of various monatomic liquids are obtained. Some other topics of current interest in this area are briefly discussed.