Two-stage assembly of patchy ellipses: From bent-core particlesto liquid crystal analogs

TL;DR

This study models a two-step assembly process of patchy ellipsoids into bent-core units and liquid crystal phases, using simulations to explore phase behavior and optimize structures.

Contribution

It introduces a binary mixture model of patchy ellipsoids that assemble into bent-core units and liquid crystal phases, analyzed through molecular simulations.

Findings

Identification of phase diagrams for bent-core liquid crystal phases

Successful optimization of bent-core unit structures

Demonstration of two-step assembly process via simulations

Abstract

We investigate the two-dimensional behavior of colloidal patchy ellipsoids specifically designed to follow a two-step assembly process from the monomer state to mesoscopic liquid-crystal phases, via the formation of so-called bent-core units at the intermediate stage. Our model comprises a binary mixture of ellipses interacting via the Gay-Berne potential and decorated by surface patches, with the binary components being mirror-image variants of each other - referred to as left-handed and right-handed ellipses according to the position of their patches. The surface patches are designed so as in the first stage of the assembly the monomers form bent-cores units, i.e. V-shaped dimers with a specific bent angle. The Gay-Berne interactions, which act between the ellipses, drive the dimers to subsequently form the characteristic phase observed in bent-core liquid crystals. We numerically investigate -- by means of both Molecular Dynamics and Monte Carlo simulations -- the described two-step process: we first optimize a target bent-core unit and we then fully characterize its state diagram in temperature and density, defining the regions where the different liquid crystalline phases dominate.