Modified carbon fiber/magnetic graphene/epoxy composites with synergistic effect for electromagnetic interference shielding over broad frequency band.

The study on electromagnetic interference (EMI) shielding materials is a long-standing project in civil and military areas. In this work, a novel kind of shielding material was fabricated and the shielding effectiveness (SE) over broad frequency was investigated. The epoxy (EP) resin was reinforced by reduced graphene oxide coated carbon fiber (rGO-CF, GCF) and FeO nanoparticles deposited rGO nanohybrids (magnetic graphene, MG). With only 0.5wt% of GCF and 9wt% of MG, the GCF/MG/EP exhibited excellent SE (>30dB over 8.2-26.5GHz) and a maximum value of 51.1dB at 26.5GHz, which had a 31.7% increase than that of GCF/EP. The 3-aminopropyltriethoxysilane (APTES) modified MG (NMG) gained better dispersion in resin and could further increased absorbing property of composites. The synergistic effect between GCF and MG raised by 3D interpenetration structure of the ternary nanocomposite was favorable for high efficient shielding in wide frequency range. This composites show promise in lightweight and high-efficiency EMI shielding field.