Du Yu, Wu Ting, Li Xiao-Long, Zhou Wei-Long, Ding Chao, Yang You-Qiang, Wei Jin-Gang, Lu Xiang, Xie Heng, Qu Jin-Ping
Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Huazhong University of Science & Technology, Wuhan 430074, PR China.
Hubei Key Laboratory of Material Chemistry and Service Failure and Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, Huazhong University of Science & Technology, Wuhan 430074, PR China.
iScience. 2022 Sep 10;25(10):105107. doi: 10.1016/j.isci.2022.105107. eCollection 2022 Oct 21.
The directional rebound and transport of water droplets plays an important role in microfluidic devices, anti-fogging, and water harvesting. Herein, an extrusion compression molding and directional stretch demolding method was used to prepare a polypropylene (PP) surface with tilt micro/nanopillars with a contact angle of 157 ± 3°. The rolling angle is the highest (9 ± 4°) when the direction of rotation is opposite the tilt direction of the micro/nanopillars, showing excellent water repellency and anisotropy of the surface. Compared with the position of the first collision of the water droplet, the position of the second collision shifted ∼1.5 mm along the tilt direction of the micro/nanopillars, driven by the surface tension component during the collision. The directional rebound behavior is controlled by the droplet energy and the tilt angle. The micro/nanopillars demonstrate excellent self-cleaning property and mechanical durability, which shows the possibility of their practical engineering applications.
水滴的定向反弹和输运在微流控器件、防雾和集水方面发挥着重要作用。在此，采用挤出压缩成型和定向拉伸脱模方法制备了具有倾斜微/纳米柱的聚丙烯（PP）表面，其接触角为157±3°。当旋转方向与微/纳米柱的倾斜方向相反时，滚动角最高（9±4°），表明该表面具有优异的疏水性和各向异性。与水滴第一次碰撞的位置相比，在碰撞过程中，受表面张力分量驱动，第二次碰撞的位置沿微/纳米柱的倾斜方向移动了约1.5毫米。定向反弹行为由液滴能量和倾斜角控制。微/纳米柱表现出优异的自清洁性能和机械耐久性，这表明了它们在实际工程应用中的可能性。
