Superhydrophobic micro-nano structured PTFE/WO3 coating on low-temperature steel with outstanding anti-pollution, anti-icing, and anti-fouling performance

The fabrication of superhydrophobic coatings on the low-temperature steels has rarely been explored to this day. Herein, we designed and fabricated a superhydrophobic micro-nano structured composite coating on the E40 low-temperature steel, which was composed of an underlying WO3 coating derived from the pulsed electrodeposition process and a top polytetrafluoroethylene (PTFE) layer obtained from the magnetron sputtering. The synergistic effect of the hierarchical micro-/nanostructures of the WO3 coating and the low surface free energy of the fluorine-containing PTFE layer makes the PTFE/WO3 coating superhydrophobic, which demonstrated a water contact angle of 159° and a water roll-off angle of ≤1°. The PTFE/WO3 coating exhibited outstanding anti-pollution properties towards both the solid pollutant such as carbon black particles and the liquid pollutant such as black ink. Importantly, the PTFE/WO3 coating demonstrated excellent anti-icing properties with low icing temperature and small ice-adhesion strength, while simultaneously possessing outstanding anti-fouling performance. The present work provides a new strategy for fabricating coatings with multifunctionality on metallic materials which can work under low-temperature and biofouling conditions.