Construction of anticorrosive coatings with emergency response closure by introducing functionalized graphene oxide

Vinyl ester resins (VER) are commonly used in the field of anticorrosive coatings. During the preparation and application of the coatings, it is inevitable to produce defects such as micro-porosity, micro-cracks, and scratches, which will reduce the barrier capacity of the anticorrosive coatings against corrosive media. In this paper, 2-(chloromethyl) pyridine is used to functionalize the silane-decorated graphene oxide for obtaining the functionalized modified graphene oxide (TGO). The aggregation of TGO nanosheets under the influence of Fe2+ ions generated by corrosion, achieving the response closure of TGO/VER coatings to hinder the diffusion path of corrosive media, thereby strengthening the anticorrosion effect of the coating. The water vapor transmission rate of TGO/VER coatings decreases significantly after immersion in Fe2+ solution. Electrochemical impedance spectroscopy tests indicate that TGO/VER coatings have better corrosion resistance compared with VER coatings, in which the impedance modulus after immersion for 100 d of 0.3TGO/VER coatings (3.93 × 1010 Ω cm2) is about four orders of magnitude greater than that of the VER coatings (5.85 × 106 Ω cm2). The TGO/VER coatings provide the responsive closure function via complexation of TGO with Fe2+ to achieve the long-term corrosion resistance. These results suggest that TGO/VER system provides an effective strategy for the preparation and application of graphene-based long-term anticorrosive coatings.