Interface modulation of chiral PPy/Fe3O4 planar microhelixes to achieve electric/magnetic-coupling and wide-band microwave absorption

Adjusting the heterogeneous dielectric/magnetic interfaces have been affirmed to be an impactful strategy for obtaining superior electromagnetic wave absorbing (EMWA) materials. Herein, PPy planar microhelixes anchored with Fe3O4 nanoparticles were constructed via a simple chemical oxypolymerization coupled with a solvothermal method. Kinetic factors (i.e., H2O volume and Fe3+ concentration) can be easily used to adjust PPy/Fe3O4 dielectric/magnetic interfaces by controlling the size and content of Fe3O4 nanoparticles in an exquisitely designed continuously adjusted process. The interface modulation not only forms superb impedance matching and significant electric/magnetic-coupling effects, but also tunes the conduction loss/polarization loss balance, beneficial to the excellent absorption performance. Interestingly, the prepared PPy/Fe3O4 planar microhelixes deliver the best EMWA performance compared with the other PPy-based absorbing materials reported so far, with the lowest reflection loss of −45.48 dB and the widest effective bandwidth of 10.24 GHz. The strategies for adjusting magnetic/electric properties and synthesizing chiral absorbers are very instructive for the development of high-performance EMW materials and devices.