Analysis of a Self-Consistent Description of Equilibrium Menisci and the Size Dependence of Their Formation in Slitlike Pores

Abstract

The distribution of the density of the adsorbate inside the transition region of the liquid–vapor interface in a slit pore, in which the density of the substance varies both along the pore width and along the transition region between the vapor and the liquid, has been investigated. Equilibrium molecular distributions at the phase boundary are described in the framework of the discrete-continuum molecular theory in the quasi-chemical approximation, which reflects the effects of direct correlations of interacting particles. The interaction of particles is described by a pair potential of the Lennard–Jones type. The self-consistency of the description of the rough meniscus profile using kinetic (through the equality of the calculated desorption and condensation rates) and equilibrium equations has been established. The probability of the formation of a liquid phase bridge between the pore walls in slotlike porous systems is considered depending on the length of the section, the pore width and the energy of the walls.