Effect of non-covalent functionalization of graphene-based nanoparticles on the local electrical properties of epoxy nanocomposites

In this study, we put forward a non-covalent π-π interaction between graphene nanoparticles (G) and a pyrene-based molecule (py) to give the functionalized graphene (G-py). The proposed modification has proven to be a winning solution aimed at safeguarding the graphene's striking electronic properties, while favoring a more effective nanofiller dispersion due to a decrease in viscosity with consequent improvement of the rheological properties of the formulated nanocomposites. Tunneling Atomic Force Microscopy (TUNA) analysis was carried out using G-py weight percentages both below and above the Electrical Percolation Threshold (EPT) to investigate the electrical behavior of the conductive nanodomains of the epoxy/graphene systems. The electrical results are in perfect agreement with the rheological ones. The non-covalent modification greatly enhances the thermal stability of the graphene-based nanoparticles, also causing an increase in the oxidative thermostability of the formulated nanocomposites.