On the build-up of effective hyperuniformity from large globular colloidal aggregates

TL;DR

This paper models colloidal aggregation using a short-range attractive and long-range repulsive potential, demonstrating how temperature and density influence cluster formation and hyperuniformity in large spherical aggregates.

Contribution

It introduces a simple 3D model capturing the emergence of hyperuniformity in colloidal clusters influenced by tunable interactions and conditions.

Findings

Cluster aggregates exhibit suppressed density fluctuations at large wavelengths.

Temperature and density control cluster size and dynamics.

Clusters can approach a glassy state while maintaining local liquid-like structure.

Abstract

A simple three-dimensional model of a fluid whose constituent particles interact via a short range attractive and long range repulsive potential is used to model the aggregation into large spherical-like clusters made up of hundreds of particles. The model can be thought of as a straightforward rendition of colloid flocculation into large spherical aggregates. We illustrate how temperature and particle density influence the cluster size distribution and affect inter- and intra-cluster dynamics. The system is shown to exhibit two well separated length and time scales, which can be tuned by the balance between repulsive and attractive forces. Interestingly, cluster aggregates at moderate/low temperatures approach a cluster glassy phase whereas cluster particles retain a local liquid-like structure. These states present a strong suppression of density fluctuations for a significant range of relatively large wavelengths, meeting the criterion of effective disordered hyperuniform materials as far as the intercluster structure is concerned.