Su Wenbo, Lu Xiangyou, Shu Yunxiang, Liu Xianshuang, Gao Wen, Yao Jianjie, Niu Zhuang, Xie Yuanlai
School of Environmental and Energy Engineering, Anhui University of Architecture, Hefei 230601, China.
Institute of Plasma Physics, Hefei Institute of Materials Science, Chinese Academy of Sciences, Hefei 230031, China.
Micromachines (Basel). 2023 Mar 22;14(3):704. doi: 10.3390/mi14030704.
The self-cleaning ability of superhydrophobic metal surfaces has attracted extensive attention. The preparation of superhydrophobic material using the coating method is a common processing method. In this experiment, aluminum fins were processed by laser etching and perfluorinated two-step coating. The aluminum surface was modified using a femtosecond laser and 1H,1H,2H,2H- perfluorooctane triethoxysilane (PFOTES). A superhydrophobic aluminum surface with excellent mechanical stability and self-cleaning properties was obtained with the superhydrophobic contact angle (WCA) of 152.8° and the rolling angle (SA) of 0.6°. The results show that the superhydrophobic surface has an excellent cleaning effect compared with an ordinary surface in unit time. Then, a wear resistance test of the superhydrophobic surface was carried out by using the physical wear method. The results show that physical wear had a low influence on the hydrophobic property of the specimen surface. Finally, the Vickers hardness analysis found that the superhydrophobic surface hardness was significantly better than the ordinary surface hardness compared with the superhydrophobic surface hardness. Based on the excellent self-cleaning properties, wear resistance, and robustness of superhydrophobic materials, the laser-etched and perfluorinated superhydrophobic aluminum fins designed and manufactured in this study have broad application prospects in improving the heat transfer efficiency of finned heat exchangers.
超疏水金属表面的自清洁能力已引起广泛关注。采用涂层法制备超疏水材料是一种常见的加工方法。在本实验中，铝翅片通过激光蚀刻和全氟两步涂层进行处理。利用飞秒激光和1H,1H,2H,2H-全氟辛基三乙氧基硅烷（PFOTES）对铝表面进行改性。获得了具有优异机械稳定性和自清洁性能的超疏水铝表面，其超疏水接触角（WCA）为152.8°，滚动角（SA）为0.6°。结果表明，与普通表面相比，超疏水表面在单位时间内具有优异的清洁效果。然后，采用物理磨损法对超疏水表面进行了耐磨性测试。结果表明，物理磨损对试样表面的疏水性影响较小。最后，维氏硬度分析发现，与普通表面硬度相比，超疏水表面硬度明显更好。基于超疏水材料优异的自清洁性能、耐磨性和坚固性，本研究设计制造的激光蚀刻和全氟超疏水铝翅片在提高翅片式换热器的传热效率方面具有广阔的应用前景。
