Structural properties and ring defect formation in discotic liquid crystal nanodroplets.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Discotic liquid crystals (DLCs) are anisotropic materials with unique self-assembly properties.
• Confining DLCs within spherical droplets can alter their bulk phase behavior and transition mechanisms.
• Understanding boundary effects is crucial for designing advanced liquid crystal materials and devices.

Purpose of the Study:

• To investigate the phase behavior of Gay-Berne discotic liquid crystals confined in spherical droplets.
• To explore the influence of face-on anchoring and fixed pressure on liquid crystal ordering.
• To identify emergent phenomena, such as disclinations, arising from confinement and boundary conditions.

Main Methods:

• Performed NpT (constant particle number, pressure, and temperature) Monte Carlo simulations.
• Utilized the Gay-Berne potential to model discotic liquid crystal interactions.
• Simulated systems confined within a spherical droplet with face-on anchoring and fixed pressure.

Main Results:

• The order parameter versus temperature plot did not show a clear first-order isotropic-nematic transition, unlike unbounded systems.
• A ring disclination line formed as a stress release mechanism due to the incompatibility of nematic order and radial boundary conditions.
• A columnar phase emerged at the center of the droplet upon further cooling.

Conclusions:

• Spherical confinement significantly modifies the isotropic-nematic transition behavior of discotic liquid crystals.
• Ring disclinations act as a critical stress relief mechanism in confined nematic systems.
• The study highlights the importance of boundary conditions in dictating the mesophase formation in confined liquid crystals.