Laboratory of Polymer Technology, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Langmuir. 2010 Mar 2;26(5):3335-41. doi: 10.1021/la903091s.
Liquid drops on textured surfaces show different dynamical behaviors depending on their wetting states. They are extremely mobile when they are supported by composite solid-liquid-air interfaces (Cassie-Baxter state) and immobile when they fully wet the textured surfaces (Wenzel state). By reversibly switching between these two states, it will be possible to achieve control over the fluid dynamics. Unfortunately, these wetting transitions are usually prevented by surface energy barriers. We demonstrate here a new, simple design paradigm consisting of parallel grooves with an appropriate aspect ratio that allows for the controlled, barrierless, reversible switching of the wetting states upon application of electrowetting. We report a direct observation of the barrierless dynamical pathway for the reversible transitions between the Wenzel (collapsed) and Cassie-Baxter (suspended) states and present a theory that accounts for these transitions, including detailed lattice Boltzmann simulations.
在具有纹理的表面上，液滴的动力学行为取决于它们的润湿状态。当它们由复合固-液-气界面支撑时（Cassie-Baxter 状态），它们会非常活跃，而当它们完全润湿纹理表面时（Wenzel 状态），它们会变得不活跃。通过在这两种状态之间可逆地切换，可以实现对流体动力学的控制。不幸的是，这些润湿转变通常会受到表面能障碍的阻止。我们在这里展示了一种新的、简单的设计范例，它由具有适当纵横比的平行槽组成，可以通过施加电润湿来控制、无阻碍、可逆地切换润湿状态。我们报告了在 Wenzel（坍塌）和 Cassie-Baxter（悬浮）状态之间的无阻碍动力学途径的直接观察，并提出了一个能够解释这些转变的理论，包括详细的格子玻尔兹曼模拟。
