Corrosion Sensing and Visualizing Epoxy Coatings Enabled by Zeolitic Imidazolate Framework Nanosensors

Coating microdamage and interfacial corrosion are inevitable for the metal/coating system during service, leading to the premature failure of the equipment and posing significant safety hazards. However, challenges remain regarding the achievement of early detection of corrosion and the visual monitoring of damage. Herein, a novel polymeric coating system exhibiting robust capabilities for corrosion sensing and visualization has been developed through the combination of meticulously designed nanosensors. These nanosensors were synthesized utilizing a zeolitic imidazolate framework that is infused with phenanthroline (Phen) corrosion probes. The onset of metal corrosion at the interface of coating damage can be promptly sensed and reflected by an apparent orange-red color, attributing to the formation of Phen-Fe 2+ coordinates. The impermeability and corrosion resistance of the epoxy coating have been greatly improved through introducing the synthesized nanosensors. This straightforward yet powerful strategy based on elaborate nanosensors, offering a new perspective for design of multifunctional and long-life protective materials.