Preparation and properties of wear-resistant superhydrophobic coatings based on SiO₂/ aramid nanofibers "grape" structure

Hydrophobic materials have shown great potential in industrial corrosion prevention due to their extremely high waterproofing properties. However, in practical applications, the micro-nano structure and low surface energy of the coating surface are continuously worn away, affecting the superhydrophobic performance. This study focuses on using polydopamine (PDA) coated aramid nanofibers (ANFs) as micro-building units to grow nano-SiO₂ through sol-gel condensation and construct a "grape-like" superhydrophobic structure through low surface energy modification. Finally, a superhydrophobic coating is obtained by spray-coating with a "binder-superhydrophobic particles" mixture. When the ethyl orthosilicate (TEOS) addition is 2.1wt%, the contact angle of the superhydrophobic coating is 158°±1.5°, respectively. The resulting coating exhibits good mechanical properties and maintains its superhydrophobic performance even after undergoing 240 cycles of abrasion on 25 μm sandpaper with a 200 g weight and a sand erosion test with a 400 g load. Nyquist testing shows a significant increase in impedance arc, and Tafel testing indicates a positive shift in corrosion potential, demonstrating that the spray-coated superhydrophobic coating can effectively enhance corrosion resistance.