Fluctuating Bond Aggregation: a Model for Chemical Gel Formation

TL;DR

This paper introduces a modified DLCA model incorporating bond fluctuations to better understand chemical gel formation, revealing a threshold concentration for gelation and differences from traditional DLCA behavior.

Contribution

It presents a novel bond fluctuation approach within DLCA simulations, identifying a critical concentration for gelation and analyzing the resulting structural properties.

Findings

Gelation threshold c_g identified

Gelling network formation prevented below c_g

Gelling time t_g does not diverge with system size

Abstract

The Diffusion-Limited Cluster-Cluster Aggregation (DLCA) model is modified by including cluster deformations using the {\it bond fluctuation} algorithm. From 3$d$ computer simulations, it is shown that, below a given threshold value $c_g$ of the volumic fraction $c$, the realization of all intra-aggregate bonding possibilities prevents the formation of a gelling network. For $c>c_g$, the sol-gel transition occurs at a time $t_g$ which, in contrast to DLCA, doesnot diverge with the box size. Several results are reported including small angle scattering curves and possible applications are discussed.