Fluctuations in Chemical Gelation

TL;DR

This paper investigates a two-dimensional chemical gelation model with monomer aggregation and bond fluctuations, revealing a sol-gel transition, structural changes post-gelation, and slow dynamics near criticality.

Contribution

It introduces a novel simulation of gelation incorporating bond fluctuations, demonstrating structural evolution and dynamic behavior near the transition.

Findings

Sol-gel transition occurs above a critical concentration.

Bond fluctuations break fractal structures, forming inhomogeneous networks.

Hierarchical pore structures and slow dynamics are observed near criticality.

Abstract

We study a chemical gelation model in two dimensions which includes both monomer aggregations and bond fluctuations. Our numerical simulation shows that a sol-gel transition occurs when an initial monomer concentration is above a critical concentration. Fractal aggregates grow until the sol-gel transition occurs. After the gelation, however, bond fluctuations break the fractal structure and a novel inhomogeneous gel fibre network appears instead. A pore size distribution of the inhomogeneous structure shows the existence of hierarchical structures in the gel phase. It is also found that slow dynamics appear near the critical concentration.