Room-temperature self-healing epoxy coating enhanced by cerium-doped ZIF-8 modified graphene oxide nanosheets toward passive/active anti-corrosion

Intrinsic self-healing coatings have attracted considerable research interest due to their remarkable ability to repair damage autonomously. However, their insufficient impermeability limits their long-term application in metal corrosion protection. Herein, we embedded corrosion-inhibiting cerium-doped ZIF-8 nanoparticles (Ce@ZIF-8) modified graphene oxide (GO) two-dimensional sheets into an epoxy network containing dynamic hydrogen bonds and disulfide bonds, developing a room-temperature self-healing epoxy/GO-Ce@ZIF-8 composite with remarkable barrier and corrosion resistance properties. Due to the metal coordination interaction between zinc or cerium in GO-Ce@ZIF-8 and the epoxy dynamic network, the modified nanosheets are efficiently and stably dispersed in the epoxy resin. The elaborately designed composite exhibits excellent stretchability (424.95 %), exceptional room-temperature self-healing capabilities (80.7 % at 25 °C for 8 h), and outstanding corrosion resistance. This is ascribed to the synergy of the superior physical shielding effect of nanosheets and the passivation of cerium elements released from nanoparticles on metal surfaces, achieving active/passive long-term corrosion protection through the intrinsic self-healing and external passivation of composite. This innovative strategy provides a new approach to developing novel high-barrier self-healing materials.