Sun Pengfei, Feng Xiaoming, Tian Guizhong, Zhang Xiaowei, Chu Jiahui
College of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China.
Langmuir. 2022 Sep 6;38(35):10875-10885. doi: 10.1021/acs.langmuir.2c01566. Epub 2022 Aug 24.
The self-healing superhydrophobic surfaces have attracted great interest owing to restoring superhydrophobicity without preparation crafts. However, the self-healing superhydrophobic surface still faces the dilemma of long repairing time. Especially in aqueous environments, superhydrophobic surfaces are highly susceptible to contamination and damage. In the current study, a superhydrophobic surface with ultrafast repairability was developed, which apply for drag reduction in aqueous medium. The prepared superhydrophobic surface can recover superhydrophobicity in only 30 s after severe physical and chemical damage. In addition, this research pioneered the combination of superhydrophobicity and porous structures for underwater drag reduction. The study of drag reduction confirms that the superhydrophobic surface can reduce the frictional drag by about 43% in the water. However, the drag reduction rate of the superhydrophobic surface with the porous structure can be improved to 76% due to increased stability of the air layer. More importantly, the porous structure with the average pore size of 50 μm has the most excellent stability through further experiments on the underwater air layer. This is attributed to the proper size of the pore to effectively balance the capillary force and resist wetting in the marginal region. This study will bring inspiration for the large-scale application of superhydrophobic surfaces and long-term drag reduction.
自愈超疏水表面由于无需制备工艺就能恢复超疏水性而备受关注。然而，自愈超疏水表面仍面临修复时间长的困境。特别是在水环境中，超疏水表面极易受到污染和损坏。在当前的研究中，开发了一种具有超快可修复性的超疏水表面，其适用于水介质中的减阻。制备的超疏水表面在受到严重物理和化学损伤后仅需30秒就能恢复超疏水性。此外，本研究率先将超疏水性与多孔结构相结合用于水下减阻。减阻研究证实，超疏水表面在水中可将摩擦阻力降低约43%。然而，由于空气层稳定性的提高，具有多孔结构的超疏水表面的减阻率可提高到76%。更重要的是，通过对水下空气层的进一步实验，平均孔径为50μm的多孔结构具有最优异的稳定性。这归因于孔隙的适当尺寸能有效平衡毛细力并抵抗边缘区域的润湿。本研究将为超疏水表面的大规模应用和长期减阻带来启示。
