Manufacture and characterization of conductor-insulator composites based on carbon nanotubes and thermally reduced graphene oxide

In this paper we present characterization data for carbon nanotube (CNT)-epoxy and thermally reduced graphene oxide (TRGO)-epoxy nano-composites. The frequency-dependent ac conductivity and permittivity are examined as a function of volume fraction of carbon-based filler. The measured electrical properties and their frequency dependency are evaluated on the basis that such composites can be considered as a network of resistors and capacitors, whereby the resistors represent the conductive component (CNT or TRGO) and the capacitors are the insulating component (epoxy matrix). Differences observed between the frequency-dependent electrical properties of the CNT-epoxy and TRGO-epoxy composites are explained in terms of the different electrical conductivities of the CNT and TRGO phase.