Flexible Poly(vinyl alcohol)/Reduced Graphene Oxide Coated Carbon Composites for Electromagnetic Interference Shielding

Flexible poly(vinyl alcohol)/reduced graphene oxide coated activated carbon (PVA/RGO@AC) composite films with extremely low graphene amounts were prepared by using AC as segregators and substrates. Decoration of AC with graphene to create an individual RGO-sheet-coated AC structure leads to a dramatic increase in the conductivity of AC and effectively prevents the restacking and agglomeration of graphene. The percolation threshold of the PVA/RGO@AC composites is as low as 0.17 wt % for RGO@AC, and, in particular, only 0.017 wt % RGO is needed. A high conductivity of 10.90 S/m and an impressive electromagnetic interference shielding effectiveness (EMI SE) of 25.6 dB with an absorption-dominated mechanism are achieved for PVA/RGO@AC composites with a low RGO loading of 1.0 wt %. The specific EMI SE of the composite reaches 17.5 dB/mm, outperforming most of the reported pioneering graphene-based polymer composites with such a low RGO amount. The excellent electrical property and outstanding EMI shielding performance are attributed to the internal well-constructed three-dimensional RGO–AC–RGO interconnected conductive network. Intriguingly, the fabricated composites exhibit a stable EMI SE even after 1000 bend–release cycles. These results demonstrate that our approach is a novel and promising method for producing highly conductive, high shielding performance, and cost-effective materials with very low graphene loading.