Construction of durable superhydrophobic/superoleophilic polyurea–based composite coating with excellent anti–corrosion/scaling properties

Superhydrophobic coatings are drawing considerable attention owing to their unique wettability, self–cleaning and anti–fouling properties. However, their widespread applications is severely limited by their fragile microstructures and unstable air films. Herein, a novel superhydrophobic/superoleophilic coating was developed via the in–situ hybridization of fluorinated polyurea (FPUA) with a SiO2 precursor, and the fluorinated TiO2 whiskers (F–TWs) were utilized to construct the multiscale reticular structures. Due to the synergistic effect of elastic FPUA and high–strength F–TWs, the prepared FPUA@SiO2/F–TWs coatings exhibit excellent mechanical properties, which can maintain superhydrophobicity after 500 abrasion cycles under 250 g load. Meanwhile, the prepared coating with selective superwettability could capture oil molecules from oil–water emulsions to replace the brittle air film with a stable lubricating film. The conversion of the isolation layer endowed the coating with excellent anti–corrosion/scaling properties in oil and water environments. The |Z|0.01Hz of the coating could be maintained above 109 Ω·cm2 after 15 d of immersion, and the surface Ca content of the coating was only 5.08 wt% after 24 h immersion in a highly mineralized oil–water emulsion. Additionally, this FPUA@SiO2/F–TWs coating demonstrated favorable comprehensive performance in terms of UV resistance, acid/alkali resistance, self–cleaning, and antifouling. Therefore, the developed FPUA@SiO2/F–TWs hybrid coating has the potential to expand the applications of superhydrophobic coatings.