Fabrication of CoFe/C@polypyrrole composites with efficient electromagnetic wave absorption properties

Recently, increasingly severe electromagnetic radiation has caused harm to precision equipment and human health, which requires the development of effective electromagnetic wave (EMW) absorption materials. These materials require both a strong absorption and a broad bandwidth at low filling rates and small thicknesses. To meet this requirement we have constructed a cobaltiron/carbon@polypyrrole (CoFe/C@PPy) composite by a two-step synthesis process. The first is the fabrication of magnetic CoFe/C fibers, followed by their coating with a PPy layer with a controlled thickness. This combination of materials results in a magnetic loss from CoFe/C and a dielectric loss from PPy which improves both impedance matching and EMW dissipation. An optimized material has a PPy layer with a thickness of 2.0 mm and a loading of 10% and has a minimum reflection loss ( RL min ) of −45.6 dB at 14.64 GHz, and the corresponding effective absorption bandwidth is 5.12 GHz. Furthermore, CST Studio simulations and far-field radar cross-section (RCS) analysis validate its practical use, showing a notable RCS reduction of up to 37.5 dBm 2 for a perfect electric conductor. Download: Download high-res image (189KB) Download: Download full-size image