Self-roughened superhydrophobic polydopamine coating with excellent self-cleaning, anti-corrosion, and UV shielding performances

Various strategies have been developed to fabricate superhydrophobic surfaces with the guidance of adding rough micro-nano structure and decreasing surface energy. However, it is still a challenge to prepare a superhydrophobic coating with multifunction, eco-friendliness, and broad applicability to substrates. The mussel-inspired polydopamine (PDA) possessing superior material-independent adhesion was considered as the promising candidate material. Herein, a hierarchical superhydrophobic PDA coating was fabricated on Cu substrate via a facile self-assembly method. Thanks to PDA's self-roughening and self-adhesive effects, the coating obtains sufficient surface roughness and good interface adhesion. The superhydrophobic coating exhibits excellent self-cleaning performance and enhanced corrosion resistance based on the surface wettability. Moreover, it possesses the additional functions of UV resistance and self-healing, inheriting from the PDA coating. PDA and the surface modifier are nontoxic, biodegradable, and eco-friendly. Our findings indicate that PDA can be used as an independent structural coating with multiple functions of corrosion protection, UV resistance, and superhydrophobic properties.