Dynamic effects of bouncing water droplets on superhydrophobic surfaces
Dynamic effects of bouncing water droplets on superhydrophobic surfaces
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DOI：
10.1021/la8003504
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发表时间：
2008-06-17
期刊：
影响因子：
3.9
通讯作者：
Bhushan, Bharat
中科院分区：
文献类型：
--
作者：
Jung, Yong Chae;Bhushan, Bharat
超疏水表面由于其极端的拒水性能而具有相当大的技术潜力用于各种应用。超疏水表面可以通过使用疏水涂层、粗糙度和固体与液体之间的气穴来产生。动态效应，如液滴的弹跳，可以破坏复合材料的固-气-液界面。液滴的撞击速度与几何参数之间的关系影响从固-气-液界面到固-液界面的转变。因此，有必要研究液滴在不同撞击速度下的动力学效应。我们研究了水滴在微图案化硅表面上的动态冲击行为，微图案化硅表面具有两种不同直径和高度的柱，并具有不同的间距值。基于撞击速度与图案化表面参数之间的关系，提出了Cassie和巴克斯特区域向Wenzel区域过渡的判据。根据实验数据和提出的过渡准则解释了这些趋势。为了比较，水滴在纳米图案化表面上的动态冲击行为进行了研究。研究了不同冲击速度下多壁纳米管阵列的润湿行为。在这里，弹跳水滴研究的润湿现象的物理是超疏水表面的几何设计中的基本重要性。
Superhydrophobic surfaces have considerable technological potential for various applications due to their extreme water repellent properties. Superhydrophobic surfaces may be generated by the use of hydrophobic coating, roughness, and air pockets between solid and liquid. Dynamic effects, such as the bouncing of a droplet, can destroy the composite solid-air-liquid interface. The relationship between the impact velocity of a droplet and the geometric parameters affects the transition from the solid-air-liquid interface to the solid-liquid interface. Therefore, it is necessary to study the dynamic effect of droplets under various impact velocities. We studied the dynamic impact behavior of water droplets on micropatterned silicon surfaces with pillars of two different diameters and heights and with varying pitch values. A criterion for the transition from the Cassie and Baxter regime to the Wenzel regime based on the relationship between the impact velocity and the parameter of patterned surfaces is proposed. The trends are explained based on the experimental data and the proposed transition criterion. For comparison, the dynamic impact behavior of water droplets on nanopatterned surfaces was investigated. The wetting behavior under various impact velocities on multiwalled nanotube arrays also was investigated. The physics of wetting phenomena for bouncing water droplet studies here is of fundamental importance in the geometrical design of superhydrophobic surfaces.