Xu Haobo, Zhou Yimin, Daniel Dan, Herzog Joshua, Wang Xiaoguang, Sick Volker, Adera Solomon
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA.
Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
Nat Commun. 2023 Aug 18;14(1):4901. doi: 10.1038/s41467-023-40279-w.
Droplets residing on textured oil-impregnated surfaces form a wetting ridge due to the imbalance of interfacial forces at the contact line, leading to a wealth of phenomena not seen on traditional lotus-leaf-inspired non-wetting surfaces. Here, we show that the wetting ridge leads to long-range attraction between millimeter-sized droplets, which coalesce in three distinct stages: droplet attraction, lubricant draining, and droplet merging. Our experiments and model show that the magnitude of the velocity and acceleration at which droplets approach each other horizontally is the same as the vertical oil rise velocity and acceleration in the wetting ridge. Moreover, the droplet coalescence mechanism can be modeled using the classical mass-spring system. The insights gained from this work will inform future fundamental studies on remote droplet interaction on textured oil-impregnated surfaces for optimizing water harvesting and condensation heat transfer.
由于接触线上界面力的不平衡，驻留在有纹理的含油表面上的液滴会形成一个润湿脊，从而导致一系列在传统荷叶灵感的非润湿表面上看不到的现象。在这里，我们表明，润湿脊会导致毫米大小的液滴之间产生远程吸引力，这些液滴在三个不同阶段合并：液滴吸引、润滑剂排出和液滴合并。我们的实验和模型表明，液滴在水平方向相互靠近时的速度和加速度大小与润湿脊中油的垂直上升速度和加速度相同。此外，液滴合并机制可以用经典的质量弹簧系统来建模。这项工作所获得的见解将为未来关于有纹理的含油表面上远程液滴相互作用的基础研究提供参考，以优化水收集和冷凝传热。
