Green Fabrication of pH-Responsive Ti₃C₂Tx@COFs Nanoplatforms for Durable Waterborne Anticorrosive Coatings

The development of high-performance anticorrosion coatings through sustainable methods is of critical importance. However, the practical applications of Ti₃C₂Tx MXene are often quite limited. This study proposes a fabrication strategy aimed at developing an intelligent, self-healing composite coating. Specifically, porous covalent organic frameworks (COFs) were grown in situ on amino-modified Ti₃C₂Tx nanosheets using a Lewis acid molten salt method combined with a room-temperature synthesis approach. This carrier possesses a high specific surface area (199.65m²·g^-1), enabling the high loading of corrosion inhibitors (PESA/BTA). When this substance is added to water-based epoxy resin, the resulting coating establishes a "passive protection + active repair" mechanism. It is worth noting that at a pH of 2, the controlled-release agent reaches its maximum efficacy within 180 min. Electrochemical tests demonstrated outstanding durability, with the low-frequency impedance modulus (|Z|_0.01 Hz) remaining at 3 × 10⁸ Ω·cm² after 60 days of exposure to 3.5 wt % NaCl. This value is 2 orders of magnitude higher than that of pure epoxy. Furthermore, the coating demonstrates rapid self-healing capabilities (impedance recovery to 5 × 10⁵ Ω·cm² within 72 h) and superior tribological properties (friction coefficient of 0.06). This study presents a scalable method for manufacturing durable MXene-based coatings.