A novel silk fibroin-graphene oxide hybrid for reinforcing corrosion protection performance of waterborne epoxy coating

The dispersion and interfacial compatibility of nanomaterials and resins are crucial to improve the barrier ability and the anticorrosion performance of the coatings. The application of graphene oxide (GO) in the field of epoxy organic coating is also limited by the above facts. Herein, we reported the preparation of a novel silk fibroin-graphene oxide (SF-GO) nanofiller and incorporated it into waterborne epoxy resins to strengthen the anticorrosive performance of the waterborne epoxy coating (WEC). Owing to the excellent dispersion and compatibility of SF-GO nanosheets and waterborne epoxy matrix, the waterborne epoxy composite coating doped with 0.5% SF-GO exhibits excellent barrier properties. The electrochemical impedance spectroscopy (EIS) test and salt spray test were performed to evaluate the corrosion resistance of the waterborne epoxy composite coatings. The results showed that the SF-GO/WEC exhibited excellent protective properties for carbon steels. The impedance modulus of 0.5% SF-GO/WEC was remained about 3.28 x 10(8) Omega.cm Omega cm(2) after immersion in 3.5 wt% NaCl solution for 60 d, which was three orders of magnitude higher than pure WEC. Additionally, 0.5% SF-GO/WEC showed excellent long-term corrosion resistance as well in the salt spray test. Our research provides a facile and green strategy to prepare GO-based fillers with high dispersibility in waterborne epoxy resins, thereby promoting the development of GO in the field of epoxy polymer.