Random packing of small blocks: pressure effects, orientational correlations and application to polymer-based composites

TL;DR

This paper introduces a novel algorithm for simulating the random packing of small, irregularly shaped blocks under pressure, aiming to replicate the structure of graphitic fillers in polymer composites and analyze their order and correlations.

Contribution

It extends the random sequential addition algorithm to handle small, irregular blocks with pressure effects, enabling realistic modeling of composite material microstructures.

Findings

Effective simulation of irregular filler packing

Pressure influences structural and orientational order

Algorithm handles diverse particle shapes efficiently

Abstract

Packing is a complex phenomenon of prominence in many natural and industrial processes (liquid crystals, granular materials, infiltration, melting, flow, sintering, segregation, sedimentation, compaction, etc.). A variety of computational methods is available in particular for spheroid particles. Our aim is to apply the principle of the random sequential addition algorithm but with small blocks of varying size and orientation. Here the main purpose is to reproduce the observed arrangement of graphitic assemblies in polymeric matrices. Random packing is improved by applying an external pressure implemented with a drifted diffusive motion of the fillers. Attention is also paid to the emergence of structural and orientational order. Interestingly, mixtures of fillers of irregular shapes can be dealt with efficiently using the proposed algorithm.