Wang Zhaochang, Liu Xiaojun, Guo Yuhang, Tong Baohong, Zhang Guotao, Liu Kun, Jiao Yunlong
School of Mechanical Engineering, Anhui University of Technology, Maanshan 243032, China.
Institute of Tribology, Hefei University of Technology, Hefei 230009, China.
Langmuir. 2024 Feb 9. doi: 10.1021/acs.langmuir.3c03544.
Superhydrophobic surfaces (SHSs) have possibilities for achieving significantly reduced solid-liquid frictional drag in the marine sector due to their excellent water-repelling properties. Although the stability of SHSs plays a key role in drag reduction, little consideration was given to the effect of extreme environments on the ability of SHSs to achieve drag reduction underwater, particularly when subjected to acidic conditions. Here, we propose interconnected microstructures to protect superhydrophobic coatings with the aim of enhancing the stability of SHSs in extreme environments. The stability of armored SHSs (ASHSs) was demonstrated by the contact angle and bounce time of droplets on superhydrophobic surfaces treated by various methods, resulting in an ASHS surface with excellent stability under extreme environmental conditions. Additionally, inspired by microstructures protecting superhydrophobic nanomaterials from frictional wear, the armored superhydrophobic spheres (ASSPs) were designed to explain from theoretical and experimental perspectives why ASSPs can achieve sustainable drag reduction and demonstrate that the ASSPs can achieve drag reduction of over 90.4% at a Reynolds number of 6.25 × 10 by conducting water entry experiments on spheres treated in various solutions. These studies promote a fundamental understanding of what drives the application of SHSs under extreme environmental conditions and provide practical strategies to maximize frictional drag reduction.
超疏水表面（SHSs）因其优异的拒水性能，在海洋领域具有显著降低固液摩擦阻力的潜力。尽管超疏水表面的稳定性在减阻中起着关键作用，但很少有人考虑极端环境对超疏水表面在水下实现减阻能力的影响，特别是在酸性条件下。在此，我们提出相互连接的微结构来保护超疏水涂层，旨在提高超疏水表面在极端环境中的稳定性。通过各种方法处理的超疏水表面上液滴的接触角和弹跳时间证明了铠装超疏水表面（ASHSs）的稳定性，从而得到了在极端环境条件下具有优异稳定性的ASHS表面。此外，受保护超疏水纳米材料免受摩擦磨损的微结构启发，设计了铠装超疏水球体（ASSPs），从理论和实验角度解释了ASSPs为何能实现可持续减阻，并通过对在各种溶液中处理过的球体进行入水实验表明，在雷诺数为6.25×10时，ASSPs的减阻率可超过90.4%。这些研究促进了对极端环境条件下超疏水表面应用驱动因素的基本理解，并提供了最大化减阻的实用策略。
