Liquid-gas separation in colloidal electrolytes

TL;DR

This study investigates the liquid-gas phase transition in a colloidal electrolyte mixture, revealing complex behavior influenced by interaction range and the formation of neutral and charged clusters in the vapor phase.

Contribution

It provides new insights into the phase behavior of colloidal electrolytes, highlighting the non-monotonous critical temperature dependence and cluster formation contrasting traditional models.

Findings

Critical temperature peaks at specific interaction ranges.

Presence of neutral and charged clusters in vapor phase.

Identification of an island of coexistence in parameter space.

Abstract

The liquid-gas transition of an electroneutral mixture of oppositely charged colloids, studied by Monte Carlo simulations, is found in the low temperature -- low density region. The critical temperature shows a non-monotonous behavior as a function of the interaction range, $\kappa^{-1}$, with a maximum at $\kappa \sigma \approx 10$, implying an island of coexistence in the $\kappa$-$\rho$ plane. The system is arranged in such a way that each particle is surrounded by shells of particles with alternating charge. In contrast with the electrolyte primitive model, both neutral and charged clusters are obtained in the vapor phase