Grand Séminaire d'Institut

Lundi 15 Juillet 2024 à 15h00.

How freezing breaks soft materials

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Most people think that damage caused by freezing is due to water's expansion as it freezes. However, in most soft materials, this actually plays a rather insignificant role. Indeed, liquids that shrink as they freeze also cause damage. Instead, freezing damage is typically caused by unfrozen water being sucked towards existing ice crystals, and feeding their growth. This can lead to huge amounts of ice expansion inside soft, wet materials. Surprisingly, this process is still not well understood. We study freezing by 3d imaging of soft materials as they cool. Although the results appear complex, I will show how damage caused by freezing can be understood in terms of well-known concepts from fracture and adhesion. Furthermore, I will show how unexpected factors, such as the polycrystallinity of ice, can play an important role in the freezing process.

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