Enhanced Corrosion Resistance and Corrosion Identification Function of the Rare-Earth Fluorescence-Waterborne Epoxy Zinc-Rich Coatings

This study explored the preparation of the rare earth complex phosphor Eu(PTA)1.5phen, which was used to modify zinc-rich protective coatings. The methods employed in this study included FTIR spectroscopy, SEM, EDS, EIS, fluorescence spectroscopy, XRD, and XPS to examine the impact of varying concentrations of Eu(PTA)1.5phen on Fe3⁺ sensing, fluorescence quenching, and the performance of the coating. The results showed that Eu(PTA)1.5phen exhibits excellent fluorescence properties, with a maximum emission intensity of 1.8 × 108 and a quantum yield of 89.26%. Fluorescence quenching by Fe3⁺ allows for the quantification of steel corrosion. Corrosion tests revealed that adding Eu(PTA)1.5phen enhanced the compactness of the zinc-rich coatings. The optimal performance was obtained when using 3 wt.% Eu(PTA)1.5phen, leading to a corrosion current density of 6.76 × 10⁻7 A/cm2. The XRD and XPS analyses indicated that introducing Eu3⁺ does not influence the corrosion products present in the coating. This research showed that zinc-rich coatings enhanced with rare earth fluorescence not only safeguarded the steel substrate but also allow for the real-time tracking of Fe3⁺ concentrations in both the coating and the substrate. This approach offers a method for timely and effective corrosion prevention and corrosion identification, providing new insights for the development of advanced protective coatings and practical applications.