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A superhydrophobic, self-healing anti-corrosion coating was prepared by in-situ growth of tungstate corrosion inhibitor intercalated layer double hydroxides (LDHs) conversion film on the AZ31B magnesium alloy and then post-sealing a hydrophobic polymer layer of ureido crosslinked polydimethylsiloxane (U-PDMS) with laurate modified LDHs power (La-LDH) on the surface. The coverage of the dense, water-repellent top layer could suppress the penetration of electrolyte into the bottom LDHs layer and preserve the intercalated tungstate inhibitor from being wasted by ion-exchange at the very beginning of immersion. The anti-corrosion performance provided by the composite film was assessed by multiple methods including, potentiodynamic polarization, open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), immersion test and scanning vibrating electrode technique (SVET). The results indicate that compared to LDHs coating, the superhydrophobic composite coating shows longer term protection and faster self-healing effect, which is of great significance to expand the potential applications of magnesium alloys.

The colonization of microbe on the material surface causes serious damage to the fields of biomedicine, water purification, and biosensors, and therefore versatile and biocompatible anti-biofouling coatings are highly demanded. Here, we fabricated a dual-functional (fouling-resist and antibacterial properties) anti-biofouling self-healing coating (DASC) with the triplex-crosslinked network (the covalent bonds, hydrogen bonds, and ionic interactions), which could be coated on 316L stainless steel substrate and demonstrated strong adhesive strength. The DASC-15 (the quaternary ammonium compounds accounts for 15 mol%) could inhibit the adhesion of biofouling due to its hydroxyethyl acrylate (HEA) and poly(ethylene glycol) methyl ether acrylate (PEGA480) units, and its anti-protein adhesion efficiency reached 90%. The presence of the quaternary ammonium compounds cations endowed the DASC-15 with excellent broad-spectrum antibacterial property, and the killing efficiency against Staphylococcus aureus and Escherichia coli was approximately 99.9%. Moreover, The DASC-15 could be repaired within 15 min under ambient condition after being scratched. The mechanical property restored to 93% of its original condition, which was derived from the destruction and recombination of the supramolecular non-covalent bonds. More prominently, larger scratches with the width of 200 μm could be repaired and the anti-biofouling property remained at the humidity of 90%. The coating is promising for biomaterial due to its strong metal adhesion, good biocompatibility, excellent anti-biofouling and outstanding self-healing properties.