Polymeric Fe₃O₄ Nanoparticle/Carbon Nanofiber Hybrid Nanocomposite Coatings for Improved Terahertz Shielding

With the rapid advancement in THz technology and continuously increasing number of electrical and electronic devices in this frequency band, highly efficient and functional THz shielding materials are required to ensure the intended working of these devices. Polymeric composites of hybrid nano-fillers including CNFs and magnetic nanoparticles possess distinctive capability of providing high shielding efficiency primarily absorptive in nature with field functional properties. In this article, lightweight polymeric nanocomposite coatings of continuous carbon nanofibers and magnetite (Fe 3 O 4 ), as potential shielding material for the THz frequency band, have been prepared using a cost-effective conventional air-spray coating method. The obtained results are quite exclusive, as the sample with 40 wt % Fe 3 O 4 outperforms at a very low thickness value of 540 μm, showing the highest SE value of ∼60 dB. These results are superior compared to the results obtained from most of the contemporary polymer composite materials, which usually provide good shielding at high thickness values in the mm range. Also, this study establishes that shielding performance of the polymeric hybrid nanocomposites (Fe 3 O 4 + CNFs) is substantially better than a single nanocomposite CNF filler previously synthesized and characterized through the same approach.