A facile method to prepare stearic acid-TiO₂/zinc composite coating with multipronged robustness, self-cleaning property, and corrosion resistance

Despite that some superhydrophobic coatings have been developed to enhance the corrosion resistance of steel, there lacks a solution that also fulfills both robustness and service durability. Taking advantage of the controlled generation of particles during electrodeposition, a multifunctional stearic acid (STA)-TiO₂/zinc composite (TZC) coating with hierarchical micro/nanostructures by codeposition of TiO₂ nanoparticles and zinc ions was prepared on carbon steel substrates. The structures of STA-TZC coating were characterized by a series of means. The micro/nanoscale structured surface based on TZC with STA overcoat imparted the prepared STA-TZC coating with outstanding superhydrophobic property; the water contact angle and sliding angle were 160±1.4° and 5.4±0.2°, respectively. According to the tests of knife scratching, adhesive tape peeling, sandpaper abrasion, and chemical corrosion resistance, the STA-TZC coating presented good mechanical and chemical stabilities. Additionally, STA-TZC coating showed excellent self-cleaning property, corrosion resistance, and superhydrophobic stability. The results indicated that filling the voids of porous zinc coating with TiO₂ nanoparticles and subsequently modifying with STA film could greatly improve the coating's resistance to corrosion and mechanical abrasion. This electrochemical codeposition-modification method has broad application prospects for exploring and preparing metal-based superhydrophobic coatings.