Dynamic particle packing in freezing colloidal suspensions

TL;DR

This paper investigates the microscopic dynamics of particle packing in freezing colloidal suspensions, revealing local patterns, the influence of non-equilibrium processes, and a model linking freezing speed and particle concentration.

Contribution

It introduces in situ analysis of particle behavior, identifies local packing patterns, and develops an analytical model connecting microscopic dynamics with macroscopic freezing parameters.

Findings

Identification of local ordered clusters and amorphous defects.

Correlation between non-equilibrium particle packing and pattern formation.

Analytical model linking freezing speed, initial concentration, and particle migration.

Abstract

In the field of freezing colloidal suspensions, it is important to understand the particle-scale behavior of particle packing. Here, we reveal the dynamics of particle packing by identifying the behavior of each single particle in situ. The typical pattern consists of locally ordered clusters and amorphous defects. The microscopic mechanism of pattern formation is ascribed to the non-equilibrium particle-packing process on the particle scale, described with the P\'eclet number. The macroscopic migration of a particle layer is also revealed by an analytical model involving parameters of freezing speed and initial volume fraction of particles.