In Situ Growth of Fe3O4 Nanoparticles in Poly(arylene ether nitrile)/Graphene/Carbon Nanotube Foams for Electromagnetic Interference Shielding

Due to the growing severity of electromagnetic radiation pollution, effective and absorption-dominated electromagnetic shielding materials must be developed. In this study, poly(arylene ether nitrile)/graphene/carbon nanotube (PEN/G/CNT) composite foam was prepared by nonsolvent induced phase separation, and Fe3O4 particles were grown in situ by co-precipitation method, obtaining PEN/G/CNT/Fe3O4 (GCF) composite foams. The successful incorporation of magnetic Fe3O4 particles was demonstrated by the scanning electron microscope images and the hysteresis loops, which was proved to effectively reduce the impedance mismatch and enhance the dielectric losses and magnetic losses of the composite foams, resulting in improved absorption and reduced secondary electromagnetic pollution. The electromagnetic interference shielding effectiveness (EMI SE) of GCF composite foams rose with the increase of Fe3O4 content and GCF with the Fe3O4 concentration of about 3.55 wt % showed the highest EMI SE of around 38 dB and the highest absorption ratio of about 94%. This effort provides a feasible and effective pathway for the fabrication of lightweight, easily scalable, heat-resistant, and absorption-dominated EMI shielding materials.