Smart Epoxy Coating: G-C3n4 Nanosheets Loaded Mofs for Enhanced Anti-Corrosion and Uv Resistance

Abstract

Large aspect ratio g-C3N4 nanosheets were successfully prepared by surface polymerization. NH2-MIL-101 was then modified on the surface of g-C3N4 nanosheets by an in-situ loading method to construct a long-term smart coating with high barrier, activity inhibition, and anti-UV aging. This novel approach marks a significant advancement in the development of smart coatings for long-term corrosion protection. Evaluation of the active corrosion inhibition of NH2-MIL-101@g-C3N4 (MCN) nanoparticles showed that the corrosion inhibition efficiency of MCN nanoparticles on carbon steel reached 79.3% after 5 hours, leading to the active inhibition capability of the MCN/EP coating. The release of Fe3+ cations and NH2-BDC organic ligands from MCN at defects formed a protective film, effectively preventing further corrosion. The MCN/EP coating maintained a high Log|Z|0.01 Hz value during the immersion period with excellent barrier properties. Notably, MCN significantly improved the water absorption, water contact angle, tensile properties, and thermomechanical properties of epoxy coatings after UV radiation, highlighting a remarkable enhancement in the coating's performance. The anti-corrosion of MCN/EP coating was unaffected by UV radiation, extending service life of the smart coating, with Log|Z|0.01 Hz values two orders of magnitude higher than pure EP after 300 hours of UV radiation. This work presented innovative coating design and preparation methods to improve the performance and functionality of anti-corrosion coatings, making significant attempts in the field.

Keywords: MOFs, Epoxy coating, long-lasting, high barrier, activity inhibition, anti-UV aging