Enhanced dielectric performance in polymer composite films with carbon nanotube-reduced graphene oxide hybrid filler

The electrical conductivity and the specific surface area of conductive fillers in conductor-insulator composite films can drastically improve the dielectric performance of those films through changing their polarization density by interfacial polarization. We have made a polymer composite film with a hybrid conductive filler material made of carbon nanotubes grown onto reduced graphene oxide platelets (rG-O/CNT). We report the effect of the rG-O/CNT hybrid filler on the dielectric performance of the composite film. The composite film had a dielectric constant of 32 with a dielectric loss of 0.051 at 0.062 wt% rG-O/CNT filler and 100 Hz, while the neat polymer film gave a dielectric constant of 15 with a dielectric loss of 0.036. This is attributed to the increased electrical conductivity and specific surface area of the rG-O/CNT hybrid filler, which results in an increase in interfacial polarization density between the hybrid filler and the polymer. Carbon nanotubes grown on reduced graphene oxide platelets (rG-O/CNT) hybrid fillers are fabricated and studied to investigate the effect on the dielectric performance of the polymer composite film. The composite film with rG-O/CNT fillers exhibited a high dielectric performance due to the increased polarization density, which was caused by enhancing the electrical conductivity and specific surface area of hybrid fillers.