Stiffening attractive suspensions with solid inclusions or granularity effect in loaded colloidal gels

TL;DR

This study investigates how solid inclusions of various sizes influence the elastic properties of colloidal gels, revealing complex interactions that can stiffen the material, supported by both simulations and experiments.

Contribution

It provides new insights into the effects of solid inclusions on gel elasticity through combined rheology simulations and experimental validation.

Findings

Solid inclusions can significantly alter gel elasticity.

The interactions depend on inclusion size and gel backbone properties.

Experimental results confirm simulation predictions.

Abstract

The elastic properties of a soft matter material can be greatly altered by the presence of solid inclusions whose microscopic properties, such as their size and interactions, can have a dramatic effect. In order to shed light on these effects we use extensive rheology computer simulations to investigate colloidal gels with solid inclusions of different size. We show that the elastic properties vary in a highly non trivial way as consequence of the interactions between the gel backbone and the inclusions. In particular, we show that the key aspects are the presence of the gel backbone and its mechanical alteration originated by the inclusions. To confirm our observations and their generality, we performed experiments on an emulsion that presents strong analogies with colloidal gels and confirms the trends observed in the simulations.