Preparation and Properties of Active Corrosion Warning and Control Coating Based on ZIF-7 Nanocontainer

A smart anti-corrosion coating with active corrosion warning and control functions was prepared through incorporation of rhodamine B hydrazide (RBH) loaded ZIF-7 nanocontainers (ZIF-7@RBH) into epoxy resin. The micro-morphology, structure and composition of ZIF-7@RBH were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The influence of ZIF-7@RBH addition on the corrosion resistance of epoxy coating was investigated by salt spray and electrochemical tests. The results show that the nanocontainer presented regular morphology and uniform size, and RBH was successfully loaded into the nanocontainer. Addition of 0.5% ZIF-7@RBH into coating was able to effectively inhibit interface corrosion expansion, and after the coating was immersion in seawater for 20 days, the low-frequency impedance modulus |Z|_0.01Hz was nearly one order of magnitude higher than that of pure epoxy coating, thus significantly improving the corrosion resistance of the coating. In addition, after the damaged coating soaking in seawater for 20 minutes, obvious fluorescence was observed at the defect, which exhibited excellent corrosion self-reporting effect.