Structural and dynamical equilibrium properties of hard board-like particles in parallel confinement

Area of Science:

• Physics
• Materials Science
• Computational Chemistry

Background:

• Particle suspensions near surfaces exhibit unique behaviors.
• Understanding confinement effects is crucial for materials design.

Purpose of the Study:

• To model diffusion of hard board-like particles (HBPs) in confined geometries.
• To investigate the influence of parallel hard walls on HBP organization and dynamics.
• To compare the behavior of prolate, dual-shaped, and oblate HBPs.

Main Methods:

• Monte Carlo and dynamic Monte Carlo simulations.
• Systematic variation of confinement (box size) at constant packing fraction (η = 0.150).
• Density functional theory calculations to confirm particle organization.

Main Results:

• Increasing wall separation recovers isotropic bulk phase behavior.
• Local particle organization near walls is stable and shape-dependent.
• Oblate HBPs show stronger wall anchoring than prolate HBPs.
• Nematic-like assemblies near walls influence dynamics, promoting planar diffusion.

Conclusions:

• Confinement significantly alters HBP diffusion dynamics compared to bulk.
• Particle shape dictates interaction with confining walls.
• Observed planar diffusion near walls suggests anisotropic transport properties.