Water super-repellent behavior of semicircular micro/nanostructured surfaces.
Water super-repellent behavior of semicircular micro/nanostructured surfaces.
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DOI：
10.1039/c8nr09489f
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发表时间：
2019-02
期刊：
影响因子：
6.7
通讯作者：
Lu Tie;Zhiguang Guo;Yongmin Liang;Weimin Liu
中科院分区：
文献类型：
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作者：
Lu Tie;Zhiguang Guo;Yongmin Liang;Weimin Liu
在本文中，我们报道了半圆形微/纳米结构表面的构建。基于热力学分析，从理论上详细讨论了半圆形微纳结构表面四种精确润湿状态的自由能（FE）和自由能势垒（FEB）以及平衡接触角（ECA）和接触角滞后（CAH）。值得注意的是，润湿行为与确切的润湿状态和半圆形微/纳米结构的基底半径或空间密切相关。此外，还证明了半圆形微纳结构表面的稳定润湿状态取决于基底空间和半径的微纳比。适当的半圆形表面微纳结构可使液滴处于稳定的Cassie-Cassie （Cc）状态。此外，纳米级半圆形表面在决定水超拒水性方面的重要作用是有效地降低或增加Cassie或Wenzel状态的微尺度基空间和半径的比例。此外，还比较研究了单半圆微观和纳米结构表面的润湿行为。微/纳米结构表面的FE和ECA均低于或高于单一微结构表面。然而，纳米尺度的半圆形表面对FEB和CAH的影响主要依赖于微尺度的润湿状态。最后，用相关实验结果验证了我们的研究。这些结果与实验结果吻合较好，为设计分层半圆形微纳结构表面的润湿行为提供了理论依据。
In this article, we report the construction of semicircular micro/nanostructured surfaces. Based on thermodynamic analysis, free energy (FE) and free energy barrier (FEB) as well as equilibrium contact angle (ECA) and contact angle hysteresis (CAH) for four exact wetting states of semicircular micro/nanostructured surfaces are theoretically discussed in detail. Notably, the wetting behavior is closely related to the exact wetting state and the base radius or space of semicircular micro/nanostructure. Furthermore, it is demonstrated that the stable wetting state of the semicircular micro/nanostructured surfaces depends on the microscale and nanoscale ratio of base space and radius. A suitable semicircular micro/nanostructure of the surface may lead to a droplet in the stable Cassie-Cassie (Cc) state. Moreover, an important role of the nanoscale semicircular surfaces in determining water super-repellence is effective in decreasing or increasing the ratio of microscale base space and radius for the Cassie or Wenzel state. Additionally, wetting behaviour of single semicircular micro- and nano-structured surfaces are comparatively investigated. The FE and ECA of micro/nanostructured surfaces are lower or higher than those of the single microstructured surfaces. However, the effects of nanoscale semicircular surfaces on the FEB and CAH mainly rely on the microscale wetting state. Finally, the related experimental results were used to verify our investigation. These results are in good agreement with the experiment, which are helpful in designing the wetting behavior of hierarchical semicircular micro/nano-structured surface.