Applied Physics Department and Department of Chemistry and Biotechnology Engineering, The Research Institute, Ariel University Center of Samaria, Post Office Box 3, Ariel 40700, Israel.
Langmuir. 2011 Jul 5;27(13):8171-6. doi: 10.1021/la2011869. Epub 2011 Jun 6.
Wetting of rough hydrophilic and hydrophobic surfaces is discussed. The stability of the Cassie state, with air trapped in relief details under the droplet, is necessary for the design of true superhydrophobic surfaces. The potential barrier separating the Cassie state and the Wenzel state, for which the substrate is completely wetted, is calculated for both hydrophobic and hydrophilic surfaces. When the surface is hydrophobic, the multiscaled roughness of pillars constituting the surface increases the potential barrier separating the Cassie and Wenzel states. When water fills the hydrophilic pore, the energy gain due to the wetting of the pore hydrophilic wall is overcompensated by the energy increase because of the growth of the high-energetic liquid-air interface. The potential barrier separating the Cassie and Wenzel states is calculated for various topographies of surfaces. Structural features of reliefs favoring enhanced hydrophobicity are elucidated.
粗糙亲水和疏水表面的润湿行为讨论。Cassie 状态的稳定性，即在液滴下的微凸起细节中截留空气，对于设计真正的超疏水表面是必要的。对于疏水和亲水表面，计算了将 Cassie 状态和 Wenzel 状态（此时基底完全被润湿）分开的势垒。当表面是疏水的时，构成表面的支柱的多尺度粗糙度会增加将 Cassie 和 Wenzel 状态分开的势垒。当水填充亲水孔时，由于孔亲水壁的润湿而导致的能量增益被由于高能液体-空气界面的生长而导致的能量增加所补偿。为各种表面形貌计算了 Cassie 和 Wenzel 状态之间的势垒。阐明了有利于增强疏水性的浮雕结构特征。
