Electromagnetic Interference Shielding of Graphene nano sheet/Polyurethane Foams

Flexible polyurethane foams were prepared with a various amount of graphene nanosheets (GNS), and their electromagnetic interference (EMI) shielding were studied. The addition of GNS endows the insulating PU foams with high electrical conductivity and improved electromagnetic interference (EMI) shielding efficiency with microwave absorption as the dominant EMI shielding mechanism. The foams show a low percolation threshold of 0.52 vol.%. EMI shielding effectiveness was tested over a frequency range of 8.2–12.4 GHz (X-band), and 21 dB shielding efficiency was obtained for 15 wt% (8.8 vol.%) GNS loading, This work provides a promising methodology to fabricate tough and lightweight GNS-PU microcellular foams with superior electrical and EMI shielding properties by simultaneously combining the functionality and reinforcement of the GNS and the toughening effect of the microcellular cells