Integrating anti-corrosion and self-healing protection: Imidazole ionic liquid synergizing with MXene for high-dispersion and anti-oxidant coating

Non-covalent modification of Ti 3 C 2 T x MXene by an imidazole ionic liquid was successfully achieved. • The dispersion and oxidation resistance of Ti 3 C 2 T x MXene were significantly enhanced. • The composite coating exhibits superior anti-corrosion performance. • The composite coating demonstrates excellent passive barrier protection and active self-healing capability. Ti 3 C 2 T x MXene is most commonly used as an anti-corrosion filler in coatings to enhance their physical barrier properties. However, the poor dispersibility and susceptibility to oxidation have limited its practical application. To address these issues, an imidazole-based ionic liquid (imidazole IL) was selected to functionally modify the surface of Ti 3 C 2 T x MXene (Ti 3 C 2 T x MXene@IL composite) through stable non-covalent interactions, and these interactions were characterized by performing density functional theory (DFT) calculations. The obtained Ti 3 C 2 T x MXene@IL composite cannot enhance the oxidation resistance, but also improve the dispersibility in epoxy resins. Moreover, a composite coating incorporating with Ti 3 C 2 T x MXene@IL showed significantly enhanced the anti-corrosion performance and service lifetime of coatings. Electrochemical impedance spectrocopy showed that the composite coating incorporating Ti 3 C 2 T x MXene@IL exhibited excellent anticorrosion performance and self-healing-like protection at damaged sites, and its impedance remained above 10 10  Ω·cm 2 throughout a 110 d immersion test, three orders of magnitude higher than that of the pure epoxy coating. This excellent long-term anti-corrosion performance can be attributed to a synergistic effect between the physical shielding property of Ti 3 C 2 T x MXene and the corrosion-inhibiting effect of imidazole IL corrosion inhibitors. Download: Download high-res image (240KB) Download: Download full-size image