The stability limit of polydisperse sticky hard spheres

TL;DR

This paper investigates the collapse behavior of polydisperse sticky hard spheres, revealing phase separation phenomena and establishing the collapse temperature, with implications for understanding mixture stability.

Contribution

It introduces the first example of phase separation in a single-peaked polydisperse mixture and calculates the collapse temperature for such systems.

Findings

Polydisperse sticky spheres also collapse at a specific temperature.

The mixture separates into fractions with narrower polydispersities.

No fluid-fluid coexistence occurs in mixtures of large and small spheres.

Abstract

It has been shown by Stell [J. Stat. Phys. 63, 1203 (1991)] that at low temperature monodisperse sticky spheres collapse to form coexisting close-packed solid and infinitely dilute gases. We show that polydisperse sticky spheres also collapse and calculate the collapse temperature. The polydisperse spheres separate into fractions with narrower polydispersities which can then solidify. This is the first example of a single-peaked polydisperse mixture phase separating. It implies that a mixture of polydisperse large hard spheres with much smaller hard spheres does not show fluid--fluid coexistence.