Efficient electromagnetic wave absorption performances dominated by exchanged resonance of lightweight PC/Fe3O4@PDA hybrid nanocomposite

For the past few years, the practical microwave absorbing materials with the features of being lightweight, efficient and adaptable to the environment have raised considerable concern. In this work, a lightweight porous carbon/Fe3O4@polydopamine (PC/Fe3O4@PDA) hybrid nanocomposite comprised of flour derived porous car-bon, adhered magnetic Fe3O4 nanospheres and conductive polymer coating was successfully prepared through a carbonization, hydrothermal and self-polymerization process. By virtue of the synergistic effect of various components with different loss mechanisms and generated heterogeneous interface, the electromagnetic wave (EMW) attenuation capability of the product was greatly enhanced with the minimum reflection loss (RLmin) of-46.67 dB at a matching thickness of 2.44 mm. Meanwhile, its optimal effective absorbing band (EAB) reached 6.96 GHz at a thickness of 2.17 mm. More attention should be paid to an intriguing phenomenon that exchanged resonance was dominant compared with other factors in determining the absorption performances of the hybrid nanocomposite, which was not reported in previous work. These excellent absorption performances coupled with the lightweight property endowed the PC/Fe3O4@PDA hybrid nanocomposite with a promising application as a novel microwave absorbing material.

Automated summary

This study successfully prepared a lightweight porous carbon/Fe3O4@polydopamine (PC/Fe3O4@PDA) hybrid nanocomposite with the features of being lightweight, efficient, and adaptable to the environment. The product showed enhanced electromagnetic wave (EMW) attenuation capability, with a minimum reflection loss of -46.67 dB and an optimal effective absorbing band of 6.96 GHz. The presence of exchanged resonance in determining the absorption performances of the hybrid nanocomposite was an intriguing phenomenon not reported in previous work. These excellent absorption performances and lightweight property make the PC/Fe3O4@PDA hybrid nanocomposite a promising microwave absorbing material.