Self-healing anticorrosive coatings inspired by the biomimetic porous organic cage nanocontainer for mussels

In harsh corrosive environments such as deep sea, it cannot meet the requirements of long-term anticorrosion by uniquely increasing the physical barrier property of a coating with lamellar Ti3C2Tx nanosheets. Thus, it is quite desirable to acquire exciting anticorrosion applications through a skillful combination of a self-healing property with the physical barrier property of lamellar nanosheets. Inspired by the adhesion mechanisms of mussels, we successfully fabricated a porous organic cage (HNQ-EN) with adhesive nature as a nanocontainer. It could easily combine with Ti3C2Tx nanosheets and advance the compatibility between Ti3C2Tx and organic resin. Meantime, the porous structure of HNQ-EN enables it to accommodate various guest molecules, such as green cerium nitrate corrosion inhibitor. The introduction of HE-Ti3C2Tx-Ce in 3.5 wt% NaCl solution made the inhibition efficiency from the initial 7.8% increase to 91.1% after immersion for 36 h. It derived from the successful release of Ce3+ from HNQ-EN and forming cerium deposited film. For the composite coating containing HE-Ti3C2Tx-Ce (EP/HE-Ti3C2Tx-Ce), the LEIS results demonstrated it showed self-healing performance provided by Ce3+. Moreover, the lowest Zf = 0.01 Hz value for EP/HE-Ti3C2Tx-Ce coating reached 4.41 × 106 Ω cm2 after immersion for 36 h, which was one magnitude larger than that of EP coating.