Demixing can occur in binary hard-sphere mixtures with negative non-additivity

Abstract

A binary fluid mixture of non-additive hard spheres characterized by a size ratio $\gamma ={\sigma }_2/{\sigma }_1<1$ and a non-additivity parameter $\Delta =2{\sigma }_{12}/({\sigma }_1+{\sigma }_2)-1$ is considered in infinitely many dimensions. From the equation of state in the second virial approximation (which is exact in the limit $d\to \infty$) a demixing transition with a critical consolute point at a packing fraction scaling as $\eta \sim d{2}^{-d}$ is found, even for slightly negative non-additivity, if $\Delta >-1/8(\ln \gamma {)}^2$. Arguments concerning the stability of the demixing with respect to freezing are provided.

4 pages, 2 figures; title changed; final paragraph added; to be published in PRE as a Rapid Communication

Cited by in corpus (3)

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