Phase-stability lines, spinodals and distribution functions for binary immiscible mixtures

Abstract

The phase-stability lines, the spinodals and the pair distribution functions for simple binary immiscible mixtures obtained from perturbation theory are improved by using Guggenheim's quasichemical approximation. The stability lines are compared with Gibbs ensemble simulations for corresponding systems of coexisting bulk phases. The quasichemical approximation is found to lead to a quantitative agreement with the Gibbs ensemble data, for three-dimensional as well as two-dimensional systems, away from the critical regions. The analytical quasichemical corrections to the pair distribution functions show a significant change in distribution, especially for the solute-solute particle distribution. The results are used to characterize the phase growth.