Rheology of Soft Glassy Materials

TL;DR

This paper introduces a generic mesoscopic model for soft glassy materials, explaining their rheological behavior through a mean-field noise temperature, revealing power law fluid behavior and a glass transition.

Contribution

It presents a unified model for soft glassy rheology, linking structural disorder and metastability to observable flow behaviors and transitions.

Findings

Power law fluid behavior with or without yield stress.

Frequency-dependent moduli near a glass transition.

Identification of a noise temperature parameter x.

Abstract

We attribute similarities in the rheology of many soft materials (foams, emulsions, slurries, etc.) to the shared features of structural disorder and metastability. A generic model for the mesoscopic dynamics of ``soft glassy matter'' is introduced, with interactions represented by a mean-field noise temperature x. We find power law fluid behavior either with (x<1) or without (1<x<2) a yield stress. For 1<x<2, both storage and loss modulus vary with frequency as $\omega^{x-1}$, becoming flat near a glass transition (x=1). Values of $x\approx 1$ may result from marginal dynamics as seen in some spin glass models.