Robust, Superhydrophobic Aluminum Fins with Excellent Mechanical Durability and Self-Cleaning Ability

Abstract

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.

Preparation and Applications of Superhydrophobic Coatings on Aluminum Alloy Surface for Anti-Corrosion and Anti-Fouling: A Mini Review

“…Subsequent modification with low surface energy substances is needed. [84,92,100] Hydrothermal method…”

“…The coating lost superhydrophobicity after rubbing 150 cm with a 1000 mesh sandpaper load of 200 g. [84] Spray nano-SiO 2 particles and 1H, 1H, 2H, 2H-perfluorodialkyltriethoxysilane modified epoxy resins.…”

Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces

“…Bio-mimic superhydrophobic surfaces have drawn rapidly increasing research interest because of their great significance for versatile applications such as self-cleaning [ 1 , 2 ], chemical detection and sensors [ 3 , 4 , 5 , 6 ], liquid droplet/gas bubble manipulation [ 7 , 8 , 9 , 10 , 11 ], icephobicity [ 12 , 13 , 14 , 15 , 16 ], immiscible liquid separation [ 17 , 18 , 19 ], enhanced heat transfer [ 20 , 21 , 22 ], and anti-corrosion [ 23 , 24 , 25 ]. However, most superhydrophobic surfaces suffer from chemical instability in harsh conditions like highly concentrated acidic/alkaline/salty solution immersion, organic solvent invasion, thermal treatment, UV irradiation, and active species exposure [ 26 , 27 , 28 ].…”

Designing Versatile Superhydrophilic Structures via an Alginate-Based Hydrophilic Plasticene

“…In general, lotus-leaf-inspired superhydrophobic and fish-scale-inspired superhydrophilic interfaces represent typical superwettable materials. Due to the superior liquid shielding ability, the superhydrophobic materials can be applied in the field of anti-icing [ 11 ], corrosion resistance [ 12 ], self-cleaning paint [ 13 , 14 ], etc. On the basis of the high affinity for water, superhydrophilic materials exhibit great potential in wound dressing [ 15 , 16 ], oil/water separation [ 17 ], microfluidics [ 18 , 19 , 20 ], etc.…”