PTC characteristic of carbon nanotube and graphene composite with polyvinylidene fluoride

MWCNT/PVDF and GNS/PVDF composites with the thickness of 120 μm were prepared by tape-casting process using polyvinylidene fluoride(PVDF) as a backing,multi-walled carbon nanotubes(MWCNT) and graphene nanoplatelets(GNS) as conductive mediums.The effects of the content of conductive medium on the conductivities and PTC properties of composite materials were studied by impedance test and microscopic analysis.The results show that the conductivities of GNS/PVDF and MWCNT/PVDF composites both increase with the increasing of the conductive medium content.In comparison,MWCNT/PVDF composites possess a better affinity and a higher PTC intensity.As the mass fraction of the conductive medium increases,the PTC intensity of MWCNT/PVDF composites first increases and then decreases,reaching its maximum value of 4.0 when the mass fraction of MWCNT is 2.5%.