Rheology of Soft Glassy Materials

TLDR

Soft materials such as foams, emulsions, and slurries exhibit similar rheology because of shared structural disorder and metastability. The study introduces a generic model for the mesoscopic dynamics of soft glassy matter. The model represents interactions via a mean‑field noise temperature x. The model predicts power‑law fluid behavior, with or without a yield stress depending on x, and for 1 < x < 2 the storage and loss moduli scale as ω^{x‑1}, becoming flat near the glass transition at x = 1, while x ≈ 1 values may arise from marginal dynamics seen in spin‑glass models.

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.