Robust and transparent superamphiphobic coating prepared via layer-by-layer spraying

Superamphiphobic surfaces have received extensive attention in fundamental research and practical application. However, it is still a challenge to use a convenient method to fabricate a superamphiphobic surface with high transparency and mechanical robustness. Here, we proposed a simple spray-coating method to prepare a superamphiphobic coating with a thickness of ~8.2 μm that has both high transmittance (>80%) and mechanical robustness. The prepared superamphiphobic coating has a micro−/nano-reentrant coordinated microstructure, which was formed by self-assembly of highly fluorinated micro-diatomite, nano-SiO2 particles, and transparent silicone resin. Tests of contact angles (CAs) and sliding angles (SAs) of the liquids with the surface tension γ ≥ 30.7 mN/m on the surfaces were performed using a volume of 3 μL. The results show that their CAs and SAs are larger than 150° and lower than 10°, respectively. Furthermore, the coating can retain both water and oil repellency even after 2.2 m abrasions with 1000 grit sandpaper under a load of 50 g or water jetting 10 min (pressure ~ 100 kPa). Thus, the superamphiphobic coating may be suitable for a wide range of applications, for its unique properties and the relatively low-cost fabrication.