Two-stage random sequential adsorption of discorectangles and disks on a two-dimensional surface

Area of Science:

• Materials Science
• Statistical Physics
• Surface Science

Background:

• Random sequential adsorption (RSA) models are crucial for understanding particle packing.
• Investigating two-stage RSA models provides insights into complex surface coverage dynamics.
• Disk and discorectangle packing on 2D surfaces are relevant to various physical phenomena.

Purpose of the Study:

• To investigate two variants of two-stage random sequential adsorption (RSA) models for packing disks and discorectangles on a 2D surface.
• To analyze the impact of initial particle deposition concentration and particle geometry on jamming coverage and percolation connectivity.
• To understand how the order of particle deposition (discs first or discorectangles first) affects packing efficiency.

Main Methods:

• Simulation of two-stage RSA models: Sticks+Disks (SD) and Disks+Sticks (DS).
• Systematic variation of key parameters: initial concentration, discorectangle aspect ratio (ɛ), and disk diameter (D).
• Analysis of jamming coverage and percolation connectivity for particles with hard-core and soft-shell structures.

Main Results:

• The initial particle layer dictates the maximum size of subsequently deposited particles (Dmax in SD, ɛmax in DS).
• Jamming coverage is dependent on the initial particle concentration and geometric parameters (D, ɛ).
• Percolation connectivity is influenced by particle geometry and the overlapping of soft shells, leading to disconnectedness.

Conclusions:

• The order of deposition in two-stage RSA models significantly impacts packing efficiency and structure.
• Pore formation by the first deposited particles plays a critical role in accommodating subsequent particles.
• Understanding these packing dynamics is essential for designing materials with specific surface properties and functionalities.