Polyvinylidene fluoride/nanocrystalline iron composite materials for EMI shielding and absorption applications

The present paper reports, novel outcome comprising experimental results on electromagnetic interference (EMI) shielding and radar signal absorption characteristics of a polymer-metal composite (PMC) based on polyvinylidene fluoride (PVDF) dispersed with varying concentration of nanocrystalline iron (n-Fe). The PVDF/n-Fe composites, prepared using mechanical blending followed by hot-molding process at an optimum pressure and temperature, exhibited better filler dispersion. The relevant parameters, i.e.; microwave permittivity, permeability, shielding effectiveness (SE) and loss factors, has been calculated using scattering parameters measured in X-band (8.2–12.4 GHz) by waveguide method. The theoretical EMI SE has also been evaluated by transmission line model using measured material parameters as the input for meaningful comparison with the experimental results. Further, a theoretical analysis of single layer PMC is performed for the absorption by assuming that the absorbing structure is backed by perfect electrical conductor. The results so obtained, confirmed an improved shielding and absorption properties of PVDF/n-Fe composites vis-à-vis its counterpart reported in literature. The findings in this work, suggest potential futuristic applications of PMC in shielding and absorption of electromagnetic waves.