Sticky Matter: Jamming and rigid cluster statistics with attractive particle interactions

TL;DR

This paper investigates how particle attraction influences the jamming transition, revealing two distinct scenarios: a continuous transition with diverging clusters for strong attraction, and a first-order transition for weak attraction, with the former being universal.

Contribution

It introduces a new understanding of jamming in attractive particle systems, identifying two distinct transition types and showing the universality of the strongly attractive scenario.

Findings

Strong attraction leads to a continuous jamming transition with diverging rigid clusters.

Weak attraction results in a first-order transition with no growing cluster size.

For any nonzero attraction, large systems exhibit the strongly attractive universality class.

Abstract

While the large majority of theoretical and numerical studies of the jamming transition consider athermal packings of purely repulsive spheres, real complex fluids and soft solids generically display attraction between particles. By studying the statistics of rigid clusters in simulations of soft particles with an attractive shell, we present evidence for two distinct jamming scenarios. Strongly attractive systems undergo a continuous transition in which rigid clusters grow and ultimately diverge in size at a critical packing fraction. Purely repulsive and weakly attractive systems jam via a first order transition, with no growing cluster size. We further show that the weakly attractive scenario is a finite size effect, so that for any nonzero attraction strength, a sufficiently large system will fall in the strongly attractive universality class. We therefore expect attractive jamming to be generic in the laboratory and in nature.