论文标题
在截短和倒截断的圆锥形孔中，液体侵入和挤出液体的自由能景观：与卡西 - 巴克斯特的意义
Free-energy landscapes of intrusion and extrusion of liquid in truncated and inverted truncated conical pores: implications to the Cassie-Baxter to Wenzel transition
论文作者
论文摘要
作为宏观液滴坐在显微镜粗糙或瓦楞纸底物上的宏观液滴的最简单模型，是宏观液滴的超疏水性卡西（CB）和Wenzel（W）状态，该底物的表面被相同的截短或倒置截断的骨孔所覆盖。当液体被压缩或拉伸时，分析了液体侵入和挤出过程的自由能景观，以使液相相对于蒸气相稳定或亚稳态。因此，该模型也与超疏水淹没底物的稳定性有关。在这项研究中，采用了宏观经典毛细管理论。即使在这个简化的模型中，两个简单的截短和倒置截短的锥体的几何形状也会带来完全不同的自由能景观。证明基于拉普拉斯压力的CB状态稳定性的一个简单标准表明不足以了解CB状态的破坏和恢复。自由能的景观表明，可能会逐渐破坏CB状态，这取决于锥形孔的方向以及液体是压缩还是拉伸。简要讨论了这些理论结果对更复杂的几何形状的扩展。
As the simplest model of transition between the superhydrophobic Cassie-Baxter (CB) and Wenzel (W) states of a macroscopic droplet sitting on a microscopically rough or corrugated substrate, a substrate whose surface is covered by identical truncated or inverted truncated conical pores is considered. The free energy landscapes of the intrusion and extrusion processes of a liquid into single pore are analyzed when the liquid is compressed or stretched so that the liquid phase is either stable or metastable relative to the vapor phase. Therefore, this model is also relevant to the stability of the superhydrophobic submerged substrates. In this study, the macroscopic classical capillary theory is adopted. Even within this simplified model, two simple geometries of truncated and inverted truncated cones lead to completely different free-energy landscapes. A simple criterion for the stability of the CB state based on Laplace pressure is shown not to be sufficient to understand the destruction and recovery of the CB state. The free-energy landscapes indicate that a gradual and an abrupt destruction of CB state is possible, which depends on the orientation of the conical pore and whether the liquid is compressed or stretched. The extensions of these theoretical results to more complex geometries are briefly discussed.
