Simulation study of anisotropic random sequential adsorption of extended objects on a triangular lattice.

Area of Science:

• Physics
• Materials Science
• Statistical Mechanics

Background:

• Random sequential adsorption (RSA) is a fundamental process in materials science.
• Understanding lattice-based adsorption is crucial for designing new materials and coatings.
• Anisotropy, or direction-dependent properties, can significantly alter adsorption behavior.

Purpose of the Study:

• To numerically investigate the effects of anisotropy on random sequential adsorption (RSA) on a 2D triangular lattice.
• To analyze how object shape and anisotropy influence jamming coverage and relaxation time.
• To explore anisotropic RSA in polydisperse mixtures of k-mers.

Main Methods:

• Monte Carlo simulations were employed to model the anisotropic RSA process.
• Objects were formed by self-avoiding lattice steps, with orientation determined by the first step.
• Unequal probabilities were assigned for object orientation along different lattice directions to introduce anisotropy.

Main Results:

• Coverage approaches jamming limit exponentially: θ(jam) - θ(t) ∝ exp(-t/σ).
• Relaxation time (σ) increases with anisotropy for elongated/asymmetrical shapes, but is unaffected for rounded/symmetrical shapes.
• Anisotropic RSA of k-mer mixtures shows strong dependencies on anisotropy, increasing the contribution of longer k-mers.

Conclusions:

• Anisotropy's impact on jamming coverage and relaxation time is shape-dependent.
• Anisotropic constraints favor longer k-mers in polydisperse mixtures, altering coverage fractions.
• The study provides insights into controlling adsorption processes through anisotropic conditions.