Effect of iron-deposited graphene oxides on the electromagnetic wave absorbing property of polymer composite films with Fe-based hollow magnetic fibers for near-field applications

Iron (Fe)-deposited graphene oxide (GO) particles with different ratios of GO to Fe were fabricated and analyzed using TEM, SEM, and VSM to optimize the fabrication conditions with respect to proper magnetization and improved dispersion. The Fe-deposited GOs with a GO:Fe mass ratio of 0.5:1 were used as secondary filler to assist the primary hollow magnetic fibers for the improvement of near-field electromagnetic absorption property measured by a microstrip line method. We prepared composite films with 30 wt% primary hollow fibers and 2 wt% of several kinds of secondary fillers: Fe-deposited GO, GO, and Fe nanoparticles. The power losses of the composite films showed that the incorporation of a small amount of Fe-deposited GO into the film alongside the hollow fibers could lead to a dramatic increase in the power loss compared to the other secondary fillers. According to the experimental results, it was concluded that this increase was due to the fact that Fe-deposited GOs, which were aligned in the in-plane direction and placed among the hollow fibers throughout the film, played a role in connecting the hollow fibers and spreading the electric and magnetic fields originating from the signal.