Mussel-inspired preparation of superhydrophobic mica nanosheets for long-term anticorrosion and self-healing performance of epoxy coatings

Research and development of coatings with long-term corrosion resistance and self-healing capabilities remains an important and pressing topic in the field of metal corrosion protection. Adding functional fillers with superhydrophobicity and excellent polymer compatibility to the organic coating is an effective way to address this issue. In this work, inspired by mussels, functional mica nanosheets (MNs) were successfully prepared by interacting catechol groups of natural urushiol (Ur) with the surface of MNs, as validated by XRD, UV-vis, FTIR, XPS, and TGA. The synthesized MNs@Ur exhibited superhydrophobic properties (150 degrees +/- 1 degrees) and great disper-sion in solvents and epoxy resin, making them ideal nanofillers for enhancing the anticorrosive performance of epoxy (EP) coatings. The electrochemical impedance spectroscopy (EIS) results revealed that the obtained MNs@Ur/EP coatings had outstanding long-term corrosion resistance (>129 d). The impedance at low frequency (|Z|(f=0.01 Hz)) of the 0.5 wt% MNs@Ur/EP coating was maintained at >10(10) Omega center dot cm(2) after 52 d of immersion, which was approximately four orders of magnitude greater than that of the pure EP coating. More importantly, the scratch test demonstrated the self-healing ability of the MNs@Ur/EP coating.