Intelligent marine waterborne epoxy coating based on functionalized multiscale nanocomposite: mechanical enhancement, self-reporting, and active/passive anti-corrosion

Corrosion activities and related accidents are significant issues for marine facilities, leading to considerable economic losses. Waterborne epoxy (EP) coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness (0 g/L volatile organic compounds). Nevertheless, several intrinsic deficiencies require improvement, such as fragile mechanical properties and defects (macro and micro), resulting in the continuous deterioration of comprehensive coating performances. In this work, a novel nanocomposite coating with mechanical enhancement, intelligent self-reporting, and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure (GO-CeMOF-P/M). Notably, the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness, which boosts the tensile strength (32.1 MPa/8.5%) and dry adhesion force (5.8 MPa) of the coating. Additionally, the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating, making it especially suitable for a variety of practical marine applications. Furthermore, following immersion of 80 d in the aggressive environment, Z_{f=0.01 Hz} value of GO-CeMOF-P/M-EP coating is 1.2 × 10¹⁰ Ω·cm², which is 164.4 times larger than that of EP coating (7.3 × 10⁷ Ω·cm²), demonstrating remarkably strengthened anti-corrosion ability. Consequently, by offering an intriguing design strategy, the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.