Novel hybrid nanocomposites based on polyvinyl alcohol/graphene/magnetite nanoparticles for high electromagnetic shielding performance

In recent times, materials with brilliant electromagnetic interference shielding (EMI) features captured the attention thanks to their applications in military, biological, and electronic apparatus. In this regard, hybrid polyvinyl alcohol/Graphene/Magnetite, PVA/Gr(x)/Fe3O4(0.1-x), nanocomposites were designed for the EMI shielding purposes. The obtained nanocomposites were characterized by various techniques like XRD, SEM, Raman, and FTIR. XRD patterns showed that the decrease in the crystallinity of the films with increasing the concentration of graphene (x) due to the decrease in the hydrogen bonding inside the nanocomposite. SEM images confirm the formation of graphene and Fe3O4 in the nano-scale with a fine dispersion in the matrix of PVA. The magnetite Fe3O4 nanoparticles show a high impact on the magnetization of the nanocomposites. The conductivity of the nanocomposite films increases with increasing the concentration of graphene (x) to be 0.32, 0.46, 0.9 and 1.87 S/cm for x = 0.02, 0.04, 0.06 and 0.08 wt%, respectively. The EMI shielding properties of the nanocomposite were performed in the X-band. The PVA/Gr/Fe3O4 nanocomposites display brilliant shielding effectiveness (SET) of 40.7 dB at 8 GHz with a very small amount of graphene x = 0.08 wt%, thanks to the synergetic effect of both graphene and magnetite nanoparticles and highest electrical conductivity of the nanocomposite. The main mechanism of shielding effectiveness is absorption. Finally, the synergetic effect, fine dispersion of nanoparticles, high magnetization, and high electrical conductivity are playing together to give this nanocomposite the advantage to be an excellent EMI shielding material. (C) 2020 Elsevier B.V. All rights reserved.