Defect configurations and dynamical behavior in a Gay-Berne nematic emulsion

TL;DR

This study uses molecular dynamics simulations to explore defect configurations and dynamical behaviors of droplets in a nematic liquid crystal, revealing how surface anchoring influences defect types and drag forces.

Contribution

It introduces a detailed simulation of a nematic emulsion with various surface anchoring conditions, elucidating defect structures and flow dynamics in such systems.

Findings

Radial anchoring induces Saturn ring defects.

Lower anchoring strengths lead to surface ring configurations.

Drag force anisotropy varies with anchoring strength.

Abstract

To model a nematic emulsion consisting of a surfactant-coated water droplet dispersed in a nematic host, we performed a molecular dynamics simulation of a droplet immersed in a system of 2048 Gay-Berne ellipsoids in a nematic phase. Strong radial anchoring at the surface of the droplet induced a Saturn ring defect configuration, consistent with theoretical predictions for very small droplets. A surface ring configuration was observed for lower radial anchoring strengths, and a pair of point defects was found near the poles of the droplet for tangential anchoring. We also simulated the falling ball experiment and measured the drag force anisotropy, in the presence of strong radial anchoring as well as zero anchoring strength.