Decoration of conjugated polyacene quinone radical (PAQR) with Fe3O4 nanospheres achieving improved impedance matching and electromagnetic wave absorption

Conjugated polymers have exhibited great potential to reform traditional electromagnetic wave absorbers owing to their advantages in tailorable electrical properties, lightweight, good processability, high environment resistance, and so on. In this work, conjugated polymer of polyacene quinone radical (PAQR) with unique nomadic polarization behavior was prepared by a solid-state polymerization process and subsequently decorated with Fe3O4 nanospheres through a solvothermal method to obtain PAQR/Fe3O4 nanocomposites. Electromagnetic wave absorbing properties of the polymer-based nanocomposites were thoroughly discussed. It was found that PAQR decorated with Fe3O4 in moderation exhibited excellent wave absorbing abilities with absorbing bandwidth of 4.8 GHz and reflection loss exceeding - 40 dB at a thin thickness around only 1.5 mm. The wave absorbing mechanisms were not only attributed to polarization loss and conduction loss of conjugated macromolecules, but also related to that the decoration of Fe3O4 significantly improved the magnetic loss abilities and impedance matching for the nanocomposites. This work firstly studied the electromagnetic properties of PAQRbased composites in GHz bands and proposed a powerful support for the development of conjugated polymer wave absorbing materials.