Interplay between Spinodal Decomposition and Glass Formation in Proteins Exhibiting Short-Range Attractions

TL;DR

This study explores how spinodal decomposition and glass formation compete in protein solutions with short-range attractions, revealing conditions that lead to gelation and characterizing the resulting gels' properties.

Contribution

It provides new insights into the interplay between phase separation and dynamical arrest in protein colloids, with precise phase diagram mapping.

Findings

Quenches below temperature Ta induce gelation via local arrest.

Rheological measurements characterize gel properties.

Phase boundaries and glass lines are precisely located.

Abstract

We investigate the competition between spinodal decomposition and dynamical arrest using aqueous solutions of the globular protein lysozyme as a model system for colloids with short-range attractions. We show that quenches below a temperature Ta lead to gel formation as a result of a local arrest of the proteindense phase during spinodal decomposition. The rheological properties of these gels allow us to use centrifugation experiments to determine the local densities of both phases and to precisely locate the gel boundary and the attractive glass line close to and within the unstable region of the phase diagram.