Nitrogen-Doped Multilayer Graphene as Functional Filler for Carbon/Polyamide 12 Nanocomposites

Herein, we report on the facile thermolysis process for producing nitrogen-doped few-layer graphene (CN) as a functional filler derived from graphite oxide (GO) and cyanamide (CA). The nitrogen content is governed by the thermolysis temperature and CA content. As compared to conventional thermally reduced GO, the nitrogen doping by GO/CA thermolysis at 800 degrees C accounts for a substantial increase of electrical filler conductivity from 48 to 467 S . cm(-1). According to XPS measurements, pyridinic, pyrrolic, and graphitic nitrogen groups were incorporated into graphene during thermolysis. Graphene/polyamide 12 (PA12) composites containing between 1 and 5 wt% were prepared by melt compounding. At 5 wt% graphene filler content, the Young's modulus was increased by +53% with respect to PA12. Whereas nitrogen doping did not affect mechanical properties of graphene/PA12, it greatly improved the electrical conductivity of both graphene and the corresponding graphene/PA12 nanocomposites. Hence, the nitrogen doping of graphene holds a great promise for improving the performance of functional graphene fillers.