Dopamine monomer functionalized Ti3C2 nanosheets and their anticorrosion improvement for waterborne epoxy coatings

MXene is becoming more and more active in the field of anticorrosion coatings. In this work, Ti3C2 nanosheets were modified with dopamine monomer and then introduced into waterborne epoxy coatings (EP). Composite coatings with unmodified Ti3C2 nanosheets were also prepared for comparison. Anticorrosion properties of the coatings were evaluated via electrochemical impedance spectroscopy and salt spray tests in detail. Dopamine monomer was readily attached to Ti3C2 nanosheets via chemical bond and saturated at 0.075 mg/mg Ti3C2. The modified Ti3C2 (D-Ti3C2) showed slightly deteriorated dispersibility in water but better dispersibility in waterborne epoxy resin relative to unmodified Ti3C2. The impedance modulus of D-Ti3C2 coatings achieved four and two orders of magnitude enhancement compared with EP and unmodified Ti3C2 coatings, respectively. The addition of D-Ti3C2 reduced the water absorption of EP by 80% after a prolonged immersion process. Superior barrier ability and enhanced dispersion of D-Ti3C2 nanosheets were responsible for the efficient enhancement of the anticorrosion performance of waterborne epoxy resin coating. (C) 2022 The Authors. Published by Elsevier B.V.