Linear and Surface Tensions in the Region of Contact Angles of a Three-Aggregate System and Relaxation Times

Abstract

An approach is formulated that allows calculation of three types of surface and linear tensions in the region of contact angles of a three-aggregate system. A molecular theory for three-aggregate systems based on the lattice gas model (LGM) is used to calculate surface tension (ST) and linear tension (LT). It provides a uniform description of molecular distributions of mixture components inside three bulk phases in different aggregate states and three types of their interfaces. The calculations are based on the Gibbs definition of STs and LTs, derived by calculating the excess free energy determined from interfaces of the mentioned phases, and experimental data on the relaxation times of mass and momentum transfer processes. For simplicity of description, a general approach is formulated for interfaces with ideal geometry: planar and spherical. Under real conditions, solid phases are typically nonequilibrium because of hindered redistribution of components. Non-equilibrium analogs of equilibrium potentials must be developed to describe these. Diffusion-type kinetic equations for unary and pair distribution functions must be used to calculate their evolution. Distributions of components of mobile vapor and liquid phases adapt to the distribution of components in solid phases. Problems in calculating STs and LTs are discussed using the example of vapor–liquid phases in a solid-phase porous matrix.