Five-dimensional imaging of freezing emulsions with solute effects

TL;DR

This paper uses 5D confocal microscopy to study how solutes influence the interaction between objects and solidification fronts in emulsions, revealing long-range effects on microstructure and droplet engulfment.

Contribution

It introduces a novel 5D imaging approach to analyze solute effects on freezing emulsions, highlighting long-range interactions and their impact on microstructure.

Findings

Solute induces long-range interactions affecting microstructure.

Local solute concentration increases promote premelting.

Solute effects influence droplet engulfment and grain boundary evolution.

Abstract

The interaction of objects with a moving solidification front is a common feature of many industrial and natural processes such as metal processing, the growth of single-crystals, the cryopreservation of cells, or the formation of sea ice. Solidification fronts interact with objects with different outcomes, from the total rejection to their complete engulfment. We image the freezing of emulsions in 5D (space, time, and solute concentration) with confocal microscopy. We show the solute induces long-range interactions that determine the solidification microstructure. The local increase of solute concentration enhances premelting, which controls the engulfment of droplets by the front and the evolution of grain boundaries. Freezing emulsions may be a good analogue of many solidification systems where objects interact with a solidification interface.