Defect configurations and dynamical behavior in a gay-berne nematic emulsion

Area of Science:

• Liquid crystal physics
• Materials science
• Computational physics

Background:

• Nematic emulsions are complex fluids with unique interfacial properties.
• Understanding droplet behavior in nematic hosts is crucial for materials science applications.
• Defect structures in liquid crystals are sensitive to surface interactions.

Purpose of the Study:

• To model a surfactant-coated water droplet in a nematic host using molecular dynamics.
• To investigate the impact of surface anchoring strength and type on defect formation.
• To analyze the hydrodynamic response, specifically drag force anisotropy, in nematic emulsions.

Main Methods:

• Molecular dynamics simulations using Gay-Berne ellipsoids.
• Modeling a dispersed droplet within a nematic liquid crystal phase.
• Simulating a falling ball experiment to measure drag forces.

Main Results:

• Strong radial anchoring induced a Saturn ring defect, consistent with theory for small droplets.
• Lower radial anchoring strengths resulted in a surface ring configuration.
• Tangential anchoring led to a pair of point defects near the droplet poles.
• Drag force anisotropy was measured for both strong radial and zero anchoring conditions.

Conclusions:

• The type and strength of surface anchoring significantly influence the topological defects in nematic emulsions.
• Simulations accurately predict defect configurations and provide insights into hydrodynamic properties.
• This study enhances the understanding of interfacial phenomena in liquid crystal systems.