Preparation of self‐healing hydrophobic coating and its anticorrosion property

In this study, a composite coating of polytetrafluoroethylene (PTFE) and fluorinated alkyl silane (FAS, C16H19F17O3Si) is prepared on AISI 304 L stainless steel. Scanning electron microscope and X‐ray photoelectron spectroscopy are used to analyze the microstructure and chemical group changes of PTFE–FAS coating (PF coating) before and after sulfuric acid (H2SO4) corrosion and after heat treatment. In addition, differential scanning calorimeter is performed to study the thermodynamic properties of PF coating. The corrosion resistance of PF coating under the above conditions is tested by the electrochemical experiment. The results show that acid and abrasion treatments can reduce the hydrophobic properties of the coatings, and the damage caused by acid is more serious. Heat treatment can repair the hydrophobic properties of the coating damaged by acid and abrasion. In addition, PF coating has an excellent corrosion resistance, but after H2SO4 treatment, the protection efficiency (PE) decreases from 89.09% to 2.51%, indicating that the corrosion resistance of PF is severely damaged. However, PE of PF coating increases to 76.83% after heat treatment. This repair ability improves the corrosion resistance of the coating. At the same time, the related mechanism is also clarified. The hydrophobicity and corrosion resistance of PF coating are reduced due to the damage of acid and abrasion, but they can be repaired by the heat treatment. In addition, the wear track of PF coating can be repaired by the heat treatment, and the wear track almost disappears with 350°C heat treatment.