Electrical properties of poly(arylene ether nitrile)/graphene nanocomposites prepared by in situ thermal reduction route

In order to obtain highly flexible polymer composites with high dielectric performance, novel poly(arylene ether nitrile) (PEN)/graphene nanocomposites were prepared by a two-step method, involving facile solution-casting for dispersing graphene oxide and followed by thermal reduction of dispersed graphene oxide at 200 °C for 2 h. The results showed that the in situ thermal reduction method can help to fabricate PEN-based nanocomposites with homogenously dispersed graphene sheets and give rise to a 236 % increase of the dielectric constant between 160 °C and 200 °C of from 10.43 to 24.65 at 50 Hz. As a result of the formation of an alternative multilayered structure of PEN and graphene sheets, a typical percolation transition was observed as the content of the graphene oxide increased. The conductivity and dielectric constant followed the percolation threshold power law, yielding a percolation threshold (f _c ) of 0.014. The corresponding critical exponent was calculated as μ = t(t + s)^− 1 = 0.83, which was in good agreement with the experimental data of μ = 0.81 as f _graphene = 0.013. This type of PEN/graphene composite with low percolation threshold can be potentially applied as novel dielectric materials.