Phase behavior of mixtures of hard ellipses: A scaled particle density functional study

TL;DR

This study uses a scaled particle density functional approach to analyze phase behavior in two-dimensional mixtures of hard convex particles, revealing how shape and aspect ratio influence phase diagrams and entropic interactions.

Contribution

It provides a detailed theoretical analysis of phase diagrams for mixtures of elliptical and rectangular particles, highlighting the role of shape and aspect ratio in entropic phase behavior.

Findings

Phase diagrams depend on particle shape and aspect ratio.

Entropic forces influence liquid-crystal textures.

Shape anisotropy affects phase stability.

Abstract

We present a scaled particle density functional study of two-dimensional binary mixtures of hard convex particles with one or both species being ellipses. In particular, we divide our study into two parts. The first part is devoted to the calculation of phase diagrams of mixtures with the same elliptical shapes, but with (i) different aspect ratios and equal particle areas, (ii) equal aspect ratios and different particle areas and (iii) with the former and the later being different. In the second study we obtain the phase diagrams corresponding to crossed-mixtures of particles with species having elliptical and rectangular shapes. We compare the phase diagram topologies and explain their main features from the entropic nature of particle interactions directly related to the anisotropies, areas, and shapes of species. The results obtained can be corroborated by experiments on granular rods where the entropic forces are very important in the stabilization of liquid-crystal textures at the stationary states.