Dehydration drives damage in the freezing of brittle hydrogels
Abstract
It is widely known that freezing breaks soft, wet materials. However, the mechanism underlying this damage is still not clear. To understand this process, we freeze model, brittle hydrogel samples, while observing the growth of ice-filled cracks that break these apart. We show that damage is not caused by the expansion of water upon freezing, or the growth of ice-filled cavities in the hydrogel. Instead, local ice growth dehydrates the surrounding hydrogel, leading to drying-induced fracture. This dehydration is driven by the process of cryosuction, whereby undercooled ice sucks nearby water towards itself, feeding its growth. Our results highlight the strong analogy between freezing damage and desiccation cracking, which we anticipate being useful for developing an understanding of both topics. Our results should also give useful insights into a wide range of freezing processes, including cryopreservation, food science and frost heave.
Cite
@article{arxiv.2401.12871,
title = {Dehydration drives damage in the freezing of brittle hydrogels},
author = {Shaohua Yang and Dominic Gerber and Yanxia Feng and Nicolas Bain and Matthias Kuster and Laura de Lorenzis and Ye Xu and Eric R. Dufresne and Robert W. Style},
journal= {arXiv preprint arXiv:2401.12871},
year = {2024}
}