Regulatable I–V behaviors of graphene nanoplatelets-carbon nanotubes/epoxy resin composite

Graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) are two kinds of significant carbon fillers of conductive switching composites with excellent nonlinear I-V property for protecting overvoltage damages of electronic equipment. In this research, GNPs-CNTs hybrid were fabricated and mixed with epoxy resin (ER) by the way of solution blending. Due to the better morphological features and conductivity of GNPs-CNTs hybrid than pure GNPs or CNTs, the GNPs-CNTs/ER composite could exhibit regulatable I-V behaviors with diverse weight ratios of graphene oxide (GO) to multiwalled carbon nanotubes (MWCNTs) and filler concentrations. Especially, the samples (A-0.7, C-0.7 and C-0.8) with proper filler concentrations and weight ratios of GO to MWCNTs could not only possess good nonlinear conductive characteristic, but exhibit stable reversibility throughout multiple measurements as well, which indicates the GNPs-CNTs/ER composite is more usable and practicable for actual overvoltage protection than previous carbon composite. Furthermore, the mechanisms of regulatable I-V behavior of GNPs-CNTs/ER composite were discussed.