Role of Interphase Region on Electrical Conductivity of Epoxy-Reduced Graphene Oxide Nanocomposites

By varying the level of graphene's surface oxidation in this paper, the thickness of the interphase region was altered, and its influence on the conductivity was investigated. Due to the similarity of water-based epoxy chemical groups with graphene oxide oxygen groups, the interphase region was reinforced. Infrared spectroscopy and thermal gravimetry were performed to evaluate the graphene oxide synthesis, and Raman spectroscopy was also performed to investigate the structural defects on graphene sheets. At first glance, based on the interphase region theory, it is expected that by increasing the oxidation rate of graphene nanosheets, the electrical conductivity of polymeric coatings will increase, and the percolation threshold will decrease. On the other hand, due to increased oxidation, the structural defect on graphene nanosheets increases, and the conductivity of the coatings is expected to decrease. Due to the opposite effect of the two factors mentioned above, the effectiveness of nanocomposite samples was studied, and the impressment of each factor was investigated in this project.