Resolving structural modifications of colloidal glasses by combining x-ray scattering and rheology

TL;DR

This paper combines x-ray scattering and rheology to directly observe how the structure of colloidal glasses changes under shear stress, linking these changes to their mechanical behavior and shear banding transition.

Contribution

It introduces a novel experimental approach that simultaneously measures structural and mechanical properties of colloidal glasses under shear.

Findings

Shear induces specific changes in the nearest neighbor configuration.

Structural changes correlate with the shear banding transition.

The method enables direct linking of structure and mechanical response.

Abstract

Glasses have liquid-like structure, but exhibit solid-like properties. A central question concerns the relation between the structure and mechanical properties of glasses, but structural changes remain difficult to resolve. We use a novel combination of rheology and x-ray scattering to resolve structural changes in colloidal glasses and link them directly to their mechanical behavior. By combining stress and structure factor measurements, we resolve shear induced changes in the nearest neighbor configuration as a function of applied stress, allowing us to elucidate the structural origin of the genuine shear banding transition of glasses.