Multifunctional Ti3C2Tx-based epoxy composite coating towards intelligent response and corrosion/wear resistance

Questions remain about the unreasonable collocation of Ti₃C₂T_x and nanocontainers resulting in the performance degradation of multi-function Ti₃C₂T_x-based epoxy composite coating. Here, mesoporous SiO₂ nanocontainers (SNT) containing both potassium thiocyanate and hexadecyl trimethyl ammonium bromide (CTAB) were loaded on MXene-based platform (SNT-on-MP) to achieve a novel epoxy coating (SNT-on-MP@EP) with the integrated functions of self-warning, self-healing, anti-corrosion and anti-wear. In the damaged area, the thiocyanate groups combined with Fe³⁺ ions to form a blood-red color display, and the formed coordination compound and CTAB as corrosion inhibitors were deposited on the metal substrate, thus showing intelligent response function. Besides, because of passive and active synergistic protection functions, the lowest-frequency impedance value of SNT-on-MP@EP maintained 5.74 × 10⁷ Ω·cm² after 4 weeks of exposure in salt water environment, which was increased by two orders of magnitude compared with pure epoxy coating. Under the reciprocating sliding friction, the wear rate of SNT-on-MP@EP reached 5.32 × 10⁻⁵ mm³/N·m, and was reduced by 58.29 %, owing to the formation of lubricant film at the friction interface and the enhancement of the deformation resistance of the coating. The reasonable collocation of SNT and Ti₃C₂T_x-based platform eliminated the problem of weak interaction between traditional inorganic nanocontainer and water-based epoxy coating, thus giving full play to the advantages of both.