Equation of state and critical point behavior of hard-core double-Yukawa fluids

TL;DR

This paper develops an analytical equation of state for hard-core double-Yukawa fluids using thermodynamic perturbation theory, analyzing phase behavior and critical points, and comparing results with simulations.

Contribution

It introduces a simple analytical equation of state for hard-core double-Yukawa fluids based on first-order thermodynamic perturbation theory, extending understanding of their phase behavior.

Findings

The equation accurately predicts the compressibility factor.

Critical point locations vary with potential parameters.

Results align well with available simulation data.

Abstract

A theoretical study on the equation of state and the critical point behavior of hard-core double-Yukawa fluids is presented. Thermodynamic perturbation theory, restricted to first order in the inverse temperature and having the hard-sphere fluid as the reference system, is used to derive a relatively simple analytical equation of state of hard-core multi-Yukawa fluids. Using such an equation of state, the compressibility factor and phase behavior of six representative hard-core double-Yukawa fluids is examined and compared with available simulation results. The effect of varying the parameters of the hard-core double-Yukawa intermolecular potential on the location of the critical point is also analyzed using different perspectives. The relevance of this analysis for fluids whose molecules interact with realistic potentials is also pointed out.