Linking particle dynamics to local connectivity in colloidal gels

TL;DR

This paper experimentally links the intermittent motion of particles in colloidal gels to their local connectivity, using a cooperative thermal debonding model to explain the structural origins of dynamical heterogeneity.

Contribution

It introduces a model connecting particle dynamics to local structure in colloidal gels, validated by experiments, enhancing understanding of their complex mechanics.

Findings

Experimental evidence of particle dynamics linked to local connectivity

A quantitative model of cooperative thermal debonding matches experimental data

Insights into the structural basis of dynamical heterogeneity in gels

Abstract

Colloidal gels are a prototypical example of a heterogeneous network solid whose complex properties are governed by thermally-activated dynamics. In this Letter we experimentally establish the connection between the intermittent dynamics of individual particles and their local connectivity. We interpret our experiments with a model that describes single-particle dynamics based on highly cooperative thermal debonding. The model, in quantitative agreement with experiments, provides a microscopic picture for the structural origin of dynamical heterogeneity in colloidal gels and sheds new light on the link between structure and the complex mechanics of these heterogeneous solids.