The roles of polymer-graphene interface and contact resistance among nanosheets in the effective conductivity of nanocomposites

The effective conductivity of graphene-based nanocomposites is suggested by the characteristics of polymer-filler interfacial areas as well as the contact resistance between the neighboring nanosheets. The interfacial properties are expressed by the effective levels of the inverse aspect ratio and the filler volume fraction. Moreover, the resistances of components in the contact regions are used to define the contact resistance, which inversely affects the effective conductivity. The obtained model is utilized to predict the effective conductivity for some examples. The discrepancy of the effective conductivity at various ranks of all factors is clarified. The interfacial conductivity directly controls the effective conductivity, while the filler conductivity plays a dissimilar role in the effective conductivity, due to the incomplete interfacial adhesion. A high operative conductivity is also achieved by small contact distances and high interfacial properties. Additionally, big contact diameters and little tunnel resistivity decrease the contact resistance, thus enhancing the effective conductivity.