Impact of granular inclusions on the phase behaviour of colloidal gels

Abstract

This dataset accompanies the article "Impact of granular inclusions on the phase behaviour of colloidal gels" by Li, Royer, Sun and Ness (arXiv:2207.03864, to appear in Soft Matter). It contains the raw data for generating the plots therein, as described in README.txt. The data represent measurements of the isostatic length and viscoelastic moduli of filled and unfilled colloidal gels (Figs 1a-2d); probability distributions of the colloid-colloid contact number and void volumes (Figs 2e-3b); and phase diagrams depicting the liquid-gel boundary of filled and unfilled gels (Fig 4). Colloidal gels formed from small attractive particles are commonly used in formulations to keep larger components in suspension. However, despite extensive work characterizing unfilled gels, little is known about how larger inclusions alter the phase behavior and microstructure of the colloidal system. Here we use numerical simulations to examine how larger `granular' particles can alter the gel transition phase boundaries. We find two distinct regimes depending on both the filler size and native gel structure: a `passive' regime where the filler fits into already-present voids, giving little change in the transition, and an `active' regime where the filler no longer fits in these voids and instead perturbs the native structure. In this second regime the phase boundary is controlled by an effective colloidal volume fraction given by the available free volume.