TA/fe(III) anti-chloride coating to protect concrete

Abstract The issue of chloride induced corrosion is very common in reinforced concrete structures in a wide range of constructions, e.g., infrastructures in coastal engineering. Developing effective methods to address the issue is rather important and urgently required. Inspired by mussel adhesion on rocks along the coast, polyphenol coating is constructed through coordination-driven multistep assembly of polyphenol and metal ions on the concrete surface for the protection from chloride induced corrosion. Typically, tannic acid, a typical polyphenol, and trivalent iron cation are alternatively deposited on the concrete surface for desirable cycles. Compared to the commercial coatings, our coating shows comparable performance in reducing chloride ion penetration with a thickness of ∼1.8 μm, which is 20 times as effective in terms of reduction per unit thickness. Our study may offer a green yet inexpensive alternative to current anti-chloride coating for construction projects in need with great potential and promising application aspects.