Flexible, multifunctional, and thermally conductive nylon/graphene nanoplatelet composite papers with excellent EMI shielding performance, improved hydrophobicity and flame resistance

Composites with high thermal conductivity and excellent electromagnetic interference (EMI) shielding performance are in urgent demand in the fields of wireless communication technologies and portable intelligent electronic devices. However, it remains a great challenge to simultaneously improve thermal conductivity and EMI shielding effectiveness (SE) for polymer composites. This work reports a feasible and scaled method relating to vacuum-assisted filtration and compression-molding to fabricate nylon/graphene nanoplatelet (GNP) composite papers using commercial nylon gauze and GNPs. The results show that the composite papers exhibit good flexibility and multifunctional performances. At 11.8 wt% GNPs, the three-layered composite nylon/GNP paper, which had a thickness of about 180 μm, showed high thermal and electrical conductivities of 15.8 W m−1 K−1 and 24.3 S cm−1, respectively, and an outstanding EMI SE of 58.1 dB at the X-band (8.2–12.4 GHz). The compromise of thermal conductivity and EMI SE of the composite paper is much greater than that of other multifunctional composites reported in the literature. Specifically, the composite papers also show greatly enhanced hydrophobicity and flame resistance and satisfactory mechanical properties. To sum up, this work paves the way for the real engineering application of nylon-based composite papers in next-generation electronic devices.