Freezing of dispersions is omnipresent in science and technology. While the passing of a freezing front over a solid particle is reasonably understood, this is not so for soft particles. Here, using an oil-in-water emulsion as a model system, we show that when engulfed into a growing ice front, a soft particle severely deforms. This deformation strongly depends on the engulfment velocity $V$, even forming pointy-tip shapes for low values of $V$. We find such singular deformations are mediated by interfacial flows in nanometric thin liquid films separating the nonsolidifying dispersed droplets and the solidifying bulk. We model the fluid flow in these intervening thin films using a lubrication approximation and then relate it to the deformation sustained by the dispersed droplet.

中文翻译：

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低温保存过程中薄膜介导的液滴变形

分散体的冷冻在科学技术中无处不在。虽然冷冻锋面经过固体颗粒是可以合理理解的，但对于软颗粒来说却并非如此。在这里，我们使用水包油乳液作为模型系统，表明当被吞噬到不断增长的冰锋中时，软颗粒会严重变形。这种变形很大程度上取决于吞没速度$V$，甚至为低值形成尖尖形状$V$。我们发现这种奇异变形是由纳米薄液膜中的界面流介导的，该液膜将非凝固分散液滴和凝固块体分开。我们使用润滑近似对这些介入薄膜中的流体流动进行建模，然后将其与分散液滴所维持的变形联系起来。