A mussel-inspired self-repairing superhydrophobic coating with good anti-corrosion and photothermal properties

Superhydrophobic coatings have received extensive attention due to their excellent performance in metal corrosion protection. But their practical applications are still hampered by the poor durability and stability, and complex preparation process. In our work, a self-repairing superhydrophobic coating with good anti-corrosion and photothermal properties was fabricated by the spaying method. Specifically, inspired by mussel-chemistry and the remarkable corrosion resistance of graphene, superhydrophobic composites were prepared via the Michael addition reaction between n-dodecanethiol and dopamine (DA). ZnO nanoparticles in the composite material make the structure of graphene no longer single, and the obtained composite material can be applied to various substrates after being combined with organic resin. The decrease of corrosion current density (icorr) and the increase of coating resistance (Rc) obtained respectively from potentiodynamic polarization and EIS reveal that the superhydrophobic coating can endow copper sheet with excellent corrosion resistance performance. Moreover, the coating temperature can be increased by 125 °C within 100 s under the irradiation of 3.21 Sun, showing good photothermal behavior. The superhydrophobic coating has an excellent self-repairing ability under sunlight, which is attributed to the photothermal effect that can promote the alkyl chains to migrate from the bottom to the surface of the coating. The self-repairing and corrosion resistance of the prepared coatings can improve the service life of superhydrophobic coatings and provide a new idea for metal corrosion prevention.