Enhancing electromagnetic Interference-Shielding: Flexible graphene nanoplate composites with high connectivity

Using carbon nanomaterials to fabricate nanocomposites that simultaneously exhibit high thermal and electrical conductivities and durability remains a challenge because of the low dispersibility and tendency of carbon materials to form random networks in nanocomposites. This study fabricated a composite with a graphene nanoplate (GNP)-connected surface using a GNP/thermoplastic polyurethane (TPU) core–shell. The GNP/TPU core–shell was manufactured by attaching GNPs to the TPU surface using a heat coating method. The flexible GNP/TPU composites (G/T) fabricated by the compression molding of the prepared core–shell exhibited high thermal and electrical conductivities. In particular, the in-plane and out-plane thermal conductivity of the G/T-50 reached 50.08 and 8.25 W/mK. Moreover, with a thickness of 0.18 mm, it achieved a high electrical conductivity of 198.4 S/cm and an average electromagnetic interference (EMI) shielding effectiveness (SE) of 57.8 dB in the 8.2–12.4 GHz range. The G/T-50 had a tensile strength of 6.95 MPa and stable results in the peeling and folding tests. Therefore, composites with GNP-connected surfaces can be utilized in various applications owing to their high flexibility, superior thermal and electrical conductivities, and high EMI SE.