The Square-Shoulder-Asakura-Oosawa model

TL;DR

The paper introduces the Square-Shoulder-Asakura-Oosawa model for colloidal mixtures, enabling exact effective pair interactions and providing insights into its phase behavior, advancing understanding of non-additive hard-sphere systems.

Contribution

It proposes a novel colloidal mixture model with exact effective pair interactions, facilitating study of phase behavior in non-additive hard-sphere systems.

Findings

Exact effective pair formulation when solvent fits in interstitial regions

Insights into phase diagram properties of the model

Potential applications in colloidal science

Abstract

A new model for a colloidal size-asymmetric binary mixture is proposed: The Square-Shoulder-Asakura-Oosawa. This belongs to the larger class of non-additive hard-spheres models and has the property that its effective pair formulation is exact whenever the solvent particle fits inside the interstitial region of three touching solute particles. Therefore one can study its properties from the equivalent one-component effective problem. Some remarks on the phase diagram of this new model are also addressed.