近200年来，理解油-水液滴形状和稳定性的主要方法一直是能量最小化的热力学期望，然而文献显示了马兰戈尼流的突出作用，这是一种界面张力的自适应梯度，在水中产生对流滚动。他们的实验、标度参数和线性稳定性分析表明，由此产生的马兰戈尼驱动的浅水高雷诺数流动克服了拉普拉斯压力施加的液滴形状径向对称。因此，油与水的水滴被剪切成具有独特棱角的多边形。
此外，单个液滴下的亚相流可以抑制相邻液滴的合并，从而导致丰富的多体动力学，使它们看起来有生命。在液亚相中出现的“涡旋晕”现象是一个隐变量。
附：英文原文
Title: Oil-on-water droplets faceted and stabilized by vortex halos in the subphase
Author: Li, Yitan, Pahlavan, Amir A., Chen, Yuguang, Liu, Song, Li, Yan, Stone, Howard A., Granick, Steve
Issue&Volume: 2023-1-17
Abstract: For almost 200 y, the dominant approach to understand oil-on-water droplet shape and stability has been the thermodynamic expectation of minimized energy, yet parallel literature shows the prominence of Marangoni flow, an adaptive gradient of interfacial tension that produces convection rolls in the water. Our experiments, scaling arguments, and linear stability analysis show that the resulting Marangoni-driven high-Reynolds-number flow in shallow water overcomes radial symmetry of droplet shape otherwise enforced by the Laplace pressure. As a consequence, oil-on-water droplets are sheared to become polygons with distinct edges and corners. Moreover, subphase flows beneath individual droplets can inhibit the coalescence of adjacent droplets, leading to rich many-body dynamics that makes them look alive. The phenomenon of a “vortex halo” in the liquid subphase emerges as a hidden variable.
DOI: 10.1073/pnas.2214657120
Source: https://www.pnas.org/doi/10.1073/pnas.2214657120