Contribution Oral Presentation
OBJECTS INTERACTING WITH SOLIDIFICATION FRONTS: FROM MATERIALS SCIENCE TO GEOPHYSICS AND BIOLOGY
The ice-templating of porous materials has received a great deal of attention during the past few years. This simple process, where a material suspension is simply frozen and then sublimated, provides materials with unique porous architectures, where the porosity is almost a direct replica of the frozen solvent crystals. The basic principle of ice-templating is the assembly of a second phase, usually particles, triggered by their progressive concentration increase in the inter-crystal space. This concentration mechanism can be used to induce ordering or self-assembly of various types of building blocks between the ice crystals, providing thus materials with an increasingly elaborate architecture with improved functional properties. I will present first a few examples of such materials and phenomena investigated in our group.
The interaction of objects with a moving solidification front is however a common feature of many industrial and natural processes such as metal processing, the growth of single-crystals for photovoltaics and microelectronics, the cryo-preservation of cells, the formation of sea ice, or the preparation of frozen food. Solidification fronts interact with objects with different outcomes, from the total rejection to the complete engulfment of objects. Being able to understand and control the solidification dynamics and microstructure is of primary importance in these domains. I will discuss how the recent developments in the lab with cryoconfocal microscopy may help us make progresses in these domains and revisit some of these old but still relevant problems.