The influence of hybrid decorated structures on the EMI shielding properties of epoxy composites over the X-Band

Abstract

This work primarily focuses on electromagnetic interference (EMI) shielding characteristics of copper microparticles (CuMP), Fe3O4@CuMP, and Fe3O4 nanoparticles filled epoxy composites across the X-band. The Fe3O4@CuMP hybrids were synthesized through the water-based coprecipitation technique and analyzed by EDS and SEM. The SEM analysis of the hybrids demonstrated an excellent deposition of Fe3O4 particles on the surface of CuMP. The EDS analysis of the hybrids exhibited Cu, Fe, and O elements present in the hybrid powder sample. A set of epoxy composites containing hybrids, CuMP, and Fe3O4 particles were prepared through a resin blending technique, and its electrical and EMI shielding properties were investigated. The 12 wt% CuMP-filled epoxy composites demonstrate a frequency-dependent electrical conductivity value of 3.8 × 10−9 S/cm at 25 Hz. However, the epoxy composites containing Fe3O4@CuMP hybrids did not show a percolated electrical network and exhibited lower conductivity values than the 12 wt% CuMP-filled epoxy composite. Moreover, the hybrid composites exhibited better EMI shielding effectiveness than CuMP-filled epoxy composites containing equivalent filler loading of CuMP (i.e., 12 wt%). The hybrid composite of 1 mm thick filled with 8:12 (wt%/wt%) Fe3O4:CuMP attenuated 83.4 % of EM wave power and exhibited a SET value of 7.9 dB across X-band of 8–12.4 GHz.