Fabrication and Electromagnetic Interference Shielding Properties of a Fe3O4/Polythiophene/Au Nanocomposite Film Coated by Epoxy Resin

The advancement of fifth-generation (5G) mobile communication technologies has led to an exponential increase in the utilization of electronic devices, thereby necessitating the development of lightweight and thin electromagnetic interference (EMI) shielding materials to mitigate the associated electromagnetic (EM) pollution. A multilayered EMI shielding composite was synthesized through an elaborate multistep process, with the epoxy resin positioned in the upper and lower layers as the protective coating and a multilayered nanocomposite film, composed of Fe3O4 nanoparticles, polythiophene (PTh) nanofiber arrays, and an Au nanofilm, embedded in the middle layer. The favorable combination of magnetic nanoparticles and conducting polymer (CP) nanofiber arrays resulted in an EMI shielding effect (EMI SE) of over 30 dB when Fe3O4 was used in moderate amounts, surpassing the EMI SE of the PTh nanofiber arrays/Au/epoxy resin EMI shielding composite (~23 dB) prepared through a similar process, but without the immersion in Fe3O4 nanoparticle dispersion. The improved EMI SE is attributed to the incorporation of magnetic nanoparticles, which enhanced the impedance mismatch between the arrays and air, and introduced magnetic losses that further attenuate the EM waves. This novel, lightweight, thin, multilayered EMI shielding nanocomposite film exhibits excellent EMI shielding performance and holds great potential for use in EMI shielding and protection for high-powered electronic devices.