Eco-friendly synthesis of self-reporting robust superhydrophobic coatings with damage sensitive photoluminescence

Polymer-based superhydrophobic coatings have attracted tremendous attention as promising multi-functional materials. Nevertheless, the practical applications of superhydrophobic coatings are seriously restricted by the well-known drawbacks of the pollution-carrying fabrication methods (e.g., harmful fluorinated compounds and organic solvents employed) and the fragile mechanical durability. Meanwhile, the absence of the smart response to external stimulus is another restricted factor for application as a promising smart multifunctional material. It is highly challenging to synthesize desirable self-reporting robust superhydrophobic coatings for autonomously indicating internal damages or failure development in early stages with the eco-friendly method. In this paper, the self-reporting robust superhydrophobic coatings with damage-sensitive photoluminescence (PL) were prepared by the facile, non-fluorinated, and eco-friendly method. Both the surface superhydrophobic modification of tetrapod-shaped ZnO (T-ZnO) and preparation of superhydrophobic coating were implemented with the waterborne formula. Benefited from the isotropic co-crosslinked interlocking networks constructed by covalent bonding the methacrylate copolymers onto the surface of T-ZnO and crosslinked with the methacrylate copolymers matrix, the as-prepared superhydrophobic coating showed excellent mechanical durability. The coating can still maintain high water-repellent (Contact angle (CA) = 150°) after 1000 cycles of severe mechanical abrasion. More importantly, the as-prepared superhydrophobic coating exhibited a significant PL response to the damage-related structural changes under mechanical abrasion. Furthermore, the anti-corrosion and self-cleaning properties of the as-prepared superhydrophobic coating were also evaluated. Under the merits in the synthesis method and the damage-related PL characteristics, the as-prepared superhydrophobic coating has a promising application in non-destructive detection and opens up the new possible application in engineering scopes.