Self-Assembly of Faceted Particles Triggered by a Moving Ice Front

TL;DR

This study explores how ice crystal growth can induce the self-assembly of faceted particles into porous structures, revealing mechanisms that could enable novel material design through combined experimental and modeling approaches.

Contribution

It provides the first detailed investigation of ice-driven self-assembly of faceted particles using X-ray holotomography and discrete element modeling, elucidating underlying mechanisms.

Findings

Ice growth can trigger the self-assembly of anisotropic particles.

The final packing results from a balance of forces between particles and the ice interface.

Potential applications include thermal management composite materials.

Abstract

The possibility to align and organize faceted particles in the bulk offers intriguing possibilities for the design and discovery of materials and architectures exhibiting novel functional properties. The growth of ice crystals can be used to trigger the self-assembly of large, anisotropic particles and consequently to obtain three-dimensional porous materials of large dimensions in a limited amount of time. These mechanisms have not been explored so far due to the difficulty to experimentally investigate these systems. Here we elucidate the self-assembly mechanisms of faceted particles driven by ice growth by a combination of X-ray holotomography and discrete element modeling, providing insights into both the dynamics of self-assembly and their final packing. The encapsulation of particles is the result of a delicate balance between the force exerted by the percolating network of concentrated particles and the force exerted by the moving interface. We illustrate the benefits of such self-assembly for thermal management composite materials.