Microrheological model for Kelvin-Voigt materials with micro-heterogeneities

TL;DR

This paper extends the Kelvin-Voigt model to account for heterogeneities in viscoelastic materials, providing analytical tools and validation for understanding probe particle dynamics in complex gels.

Contribution

It introduces a microrheological generalization of the Kelvin-Voigt model that captures heterogeneities and offers analytical expressions validated by simulations and experiments.

Findings

Analytical expressions for mean square displacement and diffusion coefficient.

Validation through Brownian dynamics simulations.

Application to experimental data on polyacrylamide and laponite gels.

Abstract

We introduce a generalization of the Kelvin-Voigt model in order to include and characterize heterogeneities in viscoelastic semisolid materials. By considering a microrheological approach, we present analytical expressions for the mean square displacement and for the time-dependent diffusion coefficient of probe particles immersed in a viscoelastic material described by this model. Besides validating our theoretical approach through Brownian dynamics simulations, we show how the model can be used to describe experimental data obtained for polyacrylamide and laponite gels.