Improving the helium gas barrier properties of epoxy coatings through the incorporation of graphene nanoplatelets and the influence of preparation techniques

Graphene/epoxy nanocomposite coatings were formulated by applying different dispersion and preparation methods to determine whether the coatings might be a potential gas barrier material for irradiated graphite waste which is known to release radioactive gases like tritium (H-3(2)). Helium was used as a substitute gas for tritium and the gas permeability was measured with the use of a helium leak detector. The dispersion and fabrication techniques influenced the ability of the coatings to reduce the helium gas permeability. Characterization of the graphene nanoplatelets and the composite morphology showed that the graphene nanoplatelet geometry and aspect ratio were altered by the applied dispersion techniques. The results showed that incorporating 2 wt % graphene into the epoxy matrix, combined with a multilayer fabrication method, reduced the helium gas permeability by 83% when compared to the reference epoxy samples. Modeling the gas permeability according to the tortuous path theory confirmed the aspect ratios which were estimated by the microscopic methods and particle size analysis. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42584.