Laboratoire de Synthèse et Fonctionnalisation des Céramiques, UMR 3080 CNRS/Saint-Gobain CREE, Cavaillon, France.
Sciences et Ingénierie de la Matiére Molle, ESPCI Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ Paris 06, Paris, France.
Science. 2018 Apr 20;360(6386):303-306. doi: 10.1126/science.aar4503.
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. Interaction of solidification fronts with objects leads to different outcomes, from total rejection of the objects to their complete engulfment. We imaged the freezing of emulsions in five dimensions (space, time, and solute concentration) with confocal microscopy. We showed that 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 analog of many solidification systems where objects interact with a solidification interface.
物体与移动凝固前沿的相互作用是许多工业和自然过程的共同特征，例如金属加工、单晶生长、细胞冷冻保存或海冰形成。凝固前沿与物体的相互作用会导致不同的结果，从完全排斥物体到完全吞噬物体。我们使用共聚焦显微镜对乳液在五个维度（空间、时间和溶质浓度）的冻结进行了成像。我们表明，溶质诱导了决定凝固微观结构的长程相互作用。溶质浓度的局部增加会增强预熔化，从而控制液滴被前沿吞噬以及晶界的演化。冷冻乳液可能是许多凝固体系的一个很好的模拟，在这些体系中，物体与凝固界面相互作用。
