Mussel-inspired hydrophobic modification of boron nitride nanosheets to enhance the dispersion and anticorrosive performance in polymeric coatings

Boron nitride nanosheets (BNNSs), a two-dimensional (2D) insulator material with outstanding barrier properties, are prone to aggregation owing to pi-pi interaction, which limits their use in heavy anti-corrosive coatings. In this work, urushiol (Ur), a cheap and easily available natural compound, was employed to modify BNNSs via interacting catechol groups of Ur with the surface of BNNSs inspired by mussel, which was proved by UV-vis, Raman, FTIR, and XPS. Synthesized BNNSs@Ur exhibited high hydrophobicity and dispersibility in solvents and epoxy coatings (EP), which enhanced the compatibility between the BNNSs and matrix. Electrochemical impedance spectroscopy (EIS) clearly manifested that the impedance at low frequency (vertical bar Z vertical bar(f = 0.01 Hz)) of the polymeric coating containing 0.75 wt% BNNSs@Ur was about two orders of magnitude higher than that of pure EP coating immersed in 3.5 wt% NaCl solution for 50 days. Characterization of corrosion products also evidenced that the modified BNNSs significantly enhanced the anticorrosive resistance of EP coatings via the improved barrier performance and corrosion inhibition effect of Ur, which is supposed to be extensively used as nano-reinforcing fillers in the field of corrosion protection.

Automated summary

In this study, urushiol was used to modify boron nitride nanosheets (BNNSs), making them highly dispersible and corrosion-resistant in epoxy coatings. This modification method shows great potential for the application of BNNSs in anti-corrosive coatings.