Generalized van der Waals theory of liquid-liquid phase transitions

TL;DR

This paper uses thermodynamic perturbation theory to analyze how the phase diagram of a soft-core attractive fluid with liquid-liquid transitions depends on potential parameters and reference liquid structure.

Contribution

It introduces a generalized van der Waals framework to study the influence of potential parameters on liquid-liquid phase transitions.

Findings

Liquid-liquid transition existence depends on potential parameters.

Phase diagram shape varies with potential modifications.

Structural properties of the reference liquid influence phase behavior.

Abstract

In the framework of the thermodynamic perturbation theory for fluids we study how the phase diagram of an isotropic repulsive soft-core attractive potential, where a liquid-liquid phase transition exists in addition to the standard gas-liquid phase transition, changes by varying the parameters of the potential. We show that existence of the liquid-liquid transition is determined by the interplay of the parameters of the potential and the structure of a reference liquid.