Thermally conductive MWCNTs/Fe3O4/Ti3C2T MXene multi-layer films for broadband electromagnetic interference shielding

The Ti3C2Tx MXene is thought to be a promising candidate for next-generation electromagnetic interference (EMI) shielding materials. However, its broadband shielding capability and thermal conduction performance are insufficient to meet the growing demands. Herein, we reported a layer-by-layer composite film composed of Ti3C2Tx MXene, multi-walled carbon nanotubes (MWCNTs), and Fe3O4 nanoparticles. Benefitting from the architecture and the synergistic effect of components, the obtained composite film exhibited high comprehensive performance. Specifically, the introduction of Fe3O4 magnetic nanoparticles effectively reduced the impedance mismatch between the composite film and air and enhanced the magnetic loss of the composite film. The layered structure prolonged the transmission path of electromagnetic waves inside the composite film and constructed a rich conductive network, causing interfacial polarization and ohmic loss. The results indicated that the composite film (52 μm) delivered a high EMI shielding effectiveness of 49 dB in the frequency range from X-band to Ku-band. Furthermore, the MWCNTs layers in the composite films provided numerous heat transfer channels, reducing phonon scattering during heat transfer and resulting in a maximum thermal conductivity of 8.241 W/(m K).