Time-lapse, three-dimensional in situ imaging of ice crystal growth in a colloidal silica suspension

S. Deville (1) , J. Adrien (2) , Eric Maire (2) , M. Scheele (3) , M. Di Michiel (3)

1 LSFC - Laboratoire de Synthèse et Fonctionnalisation des Céramiques
2 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
3 ESRF - European Synchrotron Radiation Facility

The freezing of colloidal suspensions is encountered in many natural and engineering processes such as the freezing of soils, food engineering, and cryobiology. It can also be used as a bio-inspired, versatile, and environmentally-friendly processing route for porous materials and composites. Yet, it is still a puzzling phenomenon with many unexplained features, due to the complexity of the system and the space and time scales at which the process should be investigated. We demonstrate here the interest of fast X-ray computed tomography to provide time-lapse, three-dimensional, in situ imaging of ice crystal growth in a colloidal silica suspension. The experimental measurements show that the local increase of colloid concentration does not affect the growth kinetics of the crystals, until the colloidal particles become closely packed. For particles much smaller than ice crystals, the concentrated colloidal suspension is equivalent to a simple liquid phase with higher viscosity and a freezing point determined by the concentration of colloidal particles.

Mots clés: solidification; solid/liquid interface; synchrotron radiation computed; tomography; freeze-casting; pattern formation

Domaines: Matériaux

S. Deville, J. Adrien, Eric Maire, M. Scheele, M. Di Michiel. Time-lapse, three-dimensional in situ imaging of ice crystal growth in a colloidal silica suspension. Acta Materialia, 2013, 61 (6), pp.2077-2086. ⟨10.1016/j.actamat.2012.12.027⟩. ⟨hal-00850901⟩