Unified study of glass and jamming rheology in soft particle systems

TL;DR

This paper investigates the complex shear rheology of soft particles near glass and jamming transitions, revealing distinct microscopic dynamics despite similar flow behaviors, and introduces a model for the crossover.

Contribution

It provides a unified numerical analysis of glass and jamming rheology in soft particles, highlighting their differences and proposing a simple crossover model.

Findings

Glass and jamming regimes show similar flow curves but differ in microscopic dynamics.

Multiple rheological regimes, including Newtonian, shear-thinning, and yield stress, are identified.

A rheological model for the glass-jamming crossover is proposed.

Abstract

We explore numerically the shear rheology of soft repulsive particles at large volume fraction. The interplay between viscous dissipation and thermal motion results in multiple rheological regimes encompassing Newtonian, shear-thinning and yield stress regimes near the `colloidal' glass transition when thermal fluctuations are important, crossing over to qualitatively similar regimes near the `jamming' transition when dissipation dominates. In the crossover regime, glass and jamming sectors coexist and give complex flow curves. Although glass and jamming limits are characterized by similar macroscopic flow curves, we show that they occur over distinct time and stress scales and correspond to distinct microscopic dynamics. We propose a simple rheological model describing the glass to jamming crossover in the flow curves, and discuss the experimental implications of our results.