Design and fabrication of superhydrophobic photothermal coating on copper mesh and its applications on anti-corrosion, anti-icing and oil-water separation

The discharge of oily wastewater, the leakage of high-viscosity oils as well as corrosion and freezing of metal equipment surfaces have not only caused large economic losses, but also posed a major threat to environmental safety, which has sparked international concern. Superhydrophobic materials inspired by lotus leaves were great options for addressing these problems because of their special surface wettability. In this study, a simple hydrothermal approach (in-situ CuxS growth) and post-modification technique (stearic acid modification) was used to create a superhydrophobic-superoleophilic-photothermal (SHPB-SOPI-PT) coating on the surface of copper mesh. The SHPB-SOPI-PT coating was found to be good self-cleaning ability, mechanical durability (ultrasonic vibration, sandpaper abrasion, tape peeling, surface bending), chemical stability (pH = 1, pH = 13, and 3.5 wt% NaCl solution) and environmental adaptability (thermal, UV aging, acid rain and long-term unprotected storage). Meanwhile, the SHPB-SOPI-PT coating offered ideal corrosion protection (η = 97.7 %), passive anti-icing performance (1800 % longer freezing time), oil-water separation performance. More importantly, the SHPB-SOPI-PT coating also provided active de-icing and high-efficient separation of high viscosity oils due to the photothermal effect of CuxS. This method of constructing multifunctional coating was easy to produce and utilize on a large scale, which could expand the serviceable range of copper-based materials.