Construction and properties of graphene oxide hydrogen-blocking coatings.

Compared with the composite coating with a single structure, the coating with a multilayer structure may possess better hydrogen barrier performance. Graphene oxide (GO) was chemically modified using polyethylene glycol diglycidyl ether (EGDE) to obtain modified graphene oxide (mGO). The introduction of epoxy groups in mGO would participate in the crosslinking reaction between the epoxy resin (EP) emulsion and the curing agent to improve the dispersion and adhesion of the middle layer in the sandwich structure. An EP/mGO/EP composite coating with a sandwich structure was prepared. The research found that the tightly stacked mGO middle layer in the sandwich structure played a crucial role. The average adhesion of the multilayer composite coating was about 9 MPa. The electrochemical impedance spectroscopy of layer 2-mGO composite coating showed that its modulus was up to 109 Ω cm2. The permeation current density ip and hydrogen content remained at low values of 1.38 μA and 1.34 ppm, respectively. The multilayer composite coating possessed not only excellent adhesion but also excellent corrosion resistance and hydrogen barrier performance. • Polyethylene glycol diglycidyl ether was used to covalently modify GO. • A "sandwich" structure composite coating of EP/mGO/EP was prepared. • The coating has excellent hydrogen resistance and corrosion resistance. [ABSTRACT FROM AUTHOR]