Dual-Stimuli Triggered Lubrication and Barrier: A Synergistic Strategy for High-Performance Tribocorrosion Protection in MXene-Based Epoxy Coatings

Although MXene-based epoxy coatings have been proven to have excellent wear and corrosion resistance, their failure in tribocorrosion environments will be accelerated. Here, tung oil-based urea-formaldehyde microcapsules were <i>in situ</i> loaded onto Ti₃C₂T_<i>x</i> MXene nanosheets (MLU) and incorporated into an epoxy coating (MLU@EP). The tribological properties of MLU@EP under tribocorrosion conditions were evaluated, and the related protective mechanisms were thoroughly investigated by the combined use of experiments, molecular dynamics simulations, and machine learning methods. As a result, MLU@EP with a pH/mechanical dual-stimulus-response exhibited significantly improved tribocorrosion resistance. The friction coefficient was reduced by 58%, while the wear rate decreased by 94% (1.6 × 10^-5 mm³/N·m). Moreover, the open circuit potential remained highly stable (Δ<i>V</i>_ocp < 0.077 V) at a more positive value. SEM-EDS images and Raman spectra revealed a time-dependent evolution of the worn surface, where progressive deposition of a tung oil/MXene-based lubricating film enhanced and stabilized lubrication with increasing friction cycles. Machine learning further decoupled the effects of friction frequency, load, and filler content over the wear cycle, confirming that the film enabled rapid lubrication and progressively improved over the wear cycle. In addition to the formation and cyclic evolution of the lubricating film, enhanced deformation resistance and effective barrier effects also contributed to the enhanced tribocorrosion performance. This work established a novel intelligent coating design methodology that enhanced tribocorrosion resistance and offers guidance for applications under complex operating conditions.