Relaxation of saturated random sequential adsorption packings of discorectangles aligned on a line

TL;DR

This study investigates how elongated particles called discorectangles relax on a line after initial random packing, analyzing the effects of aspect ratio on their orientation, distribution, and diffusion properties through numerical simulations.

Contribution

It introduces a numerical analysis of relaxation dynamics for aligned discorectangles on a line, highlighting the influence of aspect ratio on system properties and diffusion behavior.

Findings

Relaxation affects orientation order and distribution functions.

Aspect ratio influences relaxation kinetics and diffusion exponents.

Anomalous diffusion with a hopping exponent greater than 2 was observed.

Abstract

Relaxation of the packing of elongated particles (discorectangles) aligned on a line was studied numerically. The aspect ratio (length-to-width ratio) for the discorectangles was varied within the range $\varepsilon \in [1;50]$. The initial jamming (saturated) state was produced using the basic variant of the random sequential adsorption (RSA) model with random positions and orientations of particles. The relaxation was performed by allowing rotational and translational diffusion motions of the particles wile their centers remained located on the line. The effects of the aspect ratio $\varepsilon$ on the kinetics of relaxation, the orientation order parameter and the distribution function of the distances between nearest-neighbor discorectangles were analyzed. The transport properties of the resulting 1D systems were also analyzed by using the diffusion of a tracer particle (random walker) between the nearest-neighbor discorectangles. In the relaxed states the anomalous diffusion was observed having a hopping exponent $d_w>2$ dependent upon $\varepsilon$.