Core-shell nanofibers/polyurethane composites obtained through electrospinning for ultra-broadband electromagnetic wave absorption

The fabrication of nano-materials with delicate microstructure design and suitable multicomponent allocation is considered as a promising approach to meet the requirements of lightweight, high efficiency, and broadband absorption for electromagnetic wave (EMW) absorbers. Toward this end, nickel/carbon@zirconium dioxide core-shell nanofibers composited with polyurethane were successfully prepared through flexible electrospinning, carbonization, and a subsequent resin curing process. Profiting from the synergistic coactions of constituents and unique morphology, the ternary nanocomposites displayed the minimum reflection loss of - 61.7 dB at 17.1 GHz, and an ultra-broad bandwidth up to 8.3 GHz. In-depth investigation through electromagnetic parameters analysis and electric field distribution simulation indicated that the introduction of zirconium dioxide brought about the optimal impedance matching, while the existence of nickel and abundant heterogeneous interfaces contributed to diverse attenuation pathways, including interface polarization, dipoles polarization, conductivity loss, and magnetic loss. Thus, this study paved new research avenues for the design and synthesis of one-dimensional high-performance microwave absorbing materials, and enriched the application range of polyurethane matrix composites.