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A new network structure of Ce (III) modified I-Ti 3 C 2 T x (IT) (Ce@IT) was generated by covalent and/or coordination networks with a metal cation center of Ce (III) and imidazolium on the IT surface as a linker. The lamellar Ce@IT nanocomposites were formed with chemically bonded Ce-N bonds, which increased the crosslink density, ductility, and toughness of epoxy coatings, particularly by improving toughness and elongation at break. Furthermore, Ce3+ could be released from Ce@IT nanocomposites to form insoluble cerium-based oxide/hydroxide deposited on the substrate surface in the scratch areas and offer outstanding active and passive protection to epoxy coatings. [Display omitted] • A new structure of Ce (III) modified I-Ti 3 C 2 T x (Ce@IT) was generated by covalent and/or coordination networks. • Ce@IT/EP coatings with outstanding active and passive corrosion protection performance were developed. • Ce3+ could be released from Ce@IT nanocontainers to realize self-healing in the scratch areas. [ABSTRACT FROM AUTHOR]

Cr 2 CT x nanosheets were obtained through the utilization of FeCl 3 +tartaric acid to etch Cr 2 AlC, taking advantage of the disparities in redox reactions and metal complex formation capabilities. The oxidation mechanism and kinetics process of Cr 2 CT x MXene suspensions were investigated under different pH, temperature, and concentration conditions. Then, incorporating Cr 2 CT x MXene into epoxy coatings significantly improved compatibility, mechanical and anticorrosion properties, owing to the ultra-high barrier effect and oxidative properties, which enabled it to adsorb and consume H 2 O and O 2 diffused into coatings interior and generated a dense and effective Cr-based oxidation product layer. • Cr 2 CT x nanosheets were prepared through F-free ions etching. • The oxidation mechanisms and kinetics of Cr 2 CT x MXene were summarized. • Cr 2 CT x through oxidation control formed the dense Cr-based oxide layer and further improved corrosion protection. [ABSTRACT FROM AUTHOR]

With its unique structure and properties, Ti 3 C 2 T x MXene has shown great potential for application in anti-corrosion coatings in recent years. However, its good conductivity might accelerate the corrosion process if effective protective measures are not taken. Herein, we developed sulfonated polyaniline (SPANI)/imidazolium salts modified Ti 3 C 2 T x (I-Ti 3 C 2 T x) composites (SIT), which were synthesized by oxidative polymerization of o-aminobenzenesulfonic acid and aniline monomers in I-Ti 3 C 2 T x dispersion. The structure, chemical composition, and properties of epoxy (EP) coatings with different contents of SIT were evaluated by several techniques, such as SEM, TEM, XPS, XRD, FTIR, EIS, and SST (Salt Spray Test). The experimental results showed that SIT greatly enhanced the corrosion protection property of EP coating. Especially, the impedance of 0.5 wt% SIT/EP coating was maintained at 6.57 × 109 Ω cm2 after 180 days of immersion, which was much higher than that of other samples. Furthermore, LEIS test results evaluated the passivation behavior and protective effect of the coatings in the presence of artificial scratches. The excellent anti-corrosion performance of SIT/EP coatings was due to the synergistic effects of antioxidation stability, impermeability property, and self-passivation produced by the fabrication of such SIT 3D structure hybrid. • Sulfonated polyaniline (SPANI)/I-Ti 3 C 2 T x composites (SIT) were synthesized to develop a novel anti-corrosion additive. • SIT improved epoxy coatings exhibited outstanding corrosion protection ability. • The passivation effect by SPNAI could provide supplemental protection to the scratched position of the coatings. • The anti-corrosion mechanism produced by antioxidation stability, impermeability, and the passivation was proposed. [ABSTRACT FROM AUTHOR]

This research aims to improve the protective performance of coatings in harsh corrosive conditions by using functionalized self-healing microcapsules. CeO 2 /PUF MCs and PUF MCs were prepared via one-step emulsion polymerization. The microcapsules were implanted into epoxy coatings to investigate their self-healing performance. Multiple testing techniques, including SEM, FTIR, XRD, TGA, EIS, and NSS were used to characterize the morphology, crystal structure, chemical composition, thermal properties, and self-healing performance of the microcapsules and coatings. The experimental results indicated that the CeO 2 /PUF MCs had a spherical core-shell structure with a rough surface and an average diameter of 1583 nm. Meanwhile, the minimum corrosion products and the highest low-frequency impedance were found in CeO 2 /PUF MCs coating with artificial scratch, which demonstrated that the self-healing and anti-corrosion performance were significantly improved by the newly developed bi-functional microcapsules. • The novel IPDI@PUF/CeO 2 bi-functional microcapsules were prepared by a simple one-step emulation polymerization. • The IPDI core repaired the cracks of coatings, and the PUF/CeO 2 shell generated a passive film on the metallic matrix. • The CeO 2 /PUF MCs coatings had better corrosion resistance and self-healing performance. [ABSTRACT FROM AUTHOR]