Multifunctional organic-inorganic hybrid coating for enhanced bronze corrosion protection

Bronze relics with vital historical, artistic, and scientific value, are one of the significant symbolizations of human civilization. However, due to the long burial time and the change in storage conditions, an inevitable and thorny problem arises in preventing the ancient bronze relics from corrosion. Coatings have great potential for metal corrosion protection at present. This study prepared a multifunctional coating consisting of zinc oxide (ZnO), titanium dioxide (TiO₂), and fluoroethylene vinyl ether (FEVE) polymer by an organic-inorganic hybrid, which was applied onto the surface of corroded bronze using a self-assembly method and spraying. The rough structure of composite coating resembling that of the mastoid structure found on lotus leaf, effectively prolongs the transmission path of corrosive ions while preventing bronze contact with the corrosive media. Additionally, this study mainly investigated the bronze anti-corrosion mechanism through an electrochemical analysis perspective. Electrochemical tests revealed the lower corrosion current density, and the positive corrosion potential of multifunctional FEVE@ZnO/TiO₂ coating immersion in 3.5 wt% NaCl solution. The experimental results demonstrate that the synergistic effect of organic-inorganic significantly enhances corrosion resistance by retarding the corrosion process and providing active protection against corrosion. The multifunctional coating also exhibits exceptional self-cleaning properties and weatherability when without changing the bronze color and appearance. Consequently, this preparation strategy and research approach for constructing a multifunction coating has a great application prospect in the conservation of bronze relics and metal anti-corrosion.