A smart composite coating incorporated with MXene/mesoporous silica nanocontainer for enhanced anti-friction/wear properties

Excellent wear resistance is essential for coatings with anti-corrosion and self-warning functions. However, current smart coatings often fail through external friction damage. Adjusting the micro-nano structure of fillers is beneficial to the realization of synergistic effects. Here, mesoporous silica nanocontainers are in-situ loaded on MXene sheets (MSN-load-MX), and then incorporated into an epoxy coating (MSN-load-MX@EP). The experimental approaches include corrosion electrochemical testing, scratch testing, reciprocating sliding friction test, and molecular dynamics (MD) simulation, providing a comprehensive assessment of the protection performance. Based on the experimental analysis and MD results, MSN-load-MX can enhance the interaction strength between resin molecular chains, and perfect the coating structure, thus showing the effective defect warning and physical barrier effects. After 4 weeks of immersion, the |Z|0.01Hz value of MSN-load-MX@EP is two orders of magnitude higher than Pure EP and 66.81 % higher than MSN/MX@EP, indicating good corrosion resistance. Besides, MSNload-MX@EP exhibits a stable friction coefficient that is lower than those of Pure EP and MSN/MX@EP, and its wear rate is decreased by 41.59 %. MXene-based lubrication film can be smoothly generated on the friction interface and isolates the direct contact between the two friction pairs, leading to the decrease in the friction intensity and shear stress. Finally, MSN-load-MX@EP not only maintains good corrosion protection performance, but also shows excellent anti-friction and wear resistance. This work advances the wear resistance of the smart anti-corrosive coating and expands the potential applications of MXene/mesoporous silica composite epoxy coating in harsh environments.