Colloidal nanoparticles trapped by liquid-crystal defect lines: a lattice Monte Carlo simulation

Area of Science:

• Soft Matter Physics
• Materials Science
• Colloid Science

Background:

• Confined liquid crystals exhibit complex topological defects.
• Colloidal nanoparticles can interact with and manipulate these defects.

Purpose of the Study:

• To investigate the behavior of a topological disclination line in a confined liquid crystal system entangled with a colloidal nanoparticle.
• To quantify the disclination line tension using microscopic simulations.

Main Methods:

• Lattice-based Monte Carlo simulations were employed.
• Simulations mimicked laser tweezing experiments by stretching the disclination line via colloid movement.
• Constant-force simulations were used to extract the line tension.

Main Results:

• A restoring force on the disclination line was observed when the colloid was moved.
• The disclination line tension was estimated to be approximately 50 pN.
• The line tension was found to decrease as the temperature increased.

Conclusions:

• The study provides quantitative insights into the interaction between colloidal particles and topological defects in liquid crystals.
• The findings contribute to understanding the mechanical properties of confined liquid crystal systems.
• The temperature dependence of disclination line tension was experimentally validated through simulation.