摘要
Graphene aerogel(GA)is a promising lightweight and high-performance material for electromagnetic wave absorption due to its ultra-light mass.However,the impedance matching and attenuation capabilities of GA are limited by its high conductivity and constrained attenuation paths.To address this limitation,magnetic materials are often combined with GA to enhance both impedance matching and attenuation performance.Nevertheless,little attention has been given to the influence of magnetic materials with varying morphologies on the electromagnetic wave absorption(EMA)properties.In this study,CoFe_(2)O_(4) nanofibers were prepared via electrospinning technology as an alternativeto commercial CoFe_(2)0_(4) nanoparticles.Subsequently,CoFe_(2)O_(4)@GA composites were synthesized through a hydrothermal reaction in a graphene oxide(GO)solution.Moreover,the inclusion of ethylene glycol in the GO solution helped regulate the volume shrinkage of GA after the adding of CoFe_(2)O_(4),thus preventing structural instability and fragmentation.The introduction of a small quantity of magnetic nanofibers significantly enhanced the EMA performance of the CoFe_(2)O_(4)@GA composite,increasing the strongest absorption from-34.5 to-53.5 dB and widening the maximum effective absorption bandwidth(EAB)from 8.0 to 8.7 GHz.Finally,the study revealed that CoFe_(2)O_(4) nanofibers outperformed nanoparticles in electromagnetic wave loss mechanisms,including magnetic coupling,magnetic resonance,eddy current loss,and interface polarization.This finding provides valuable insights for the selection and optimization of magnetic component morphologies in EMA materials.
基金
The authors gratefully acknowledge the financial support for this work by the Beijing Municipal Key Fund Project(No.LZY2023043014)
the Fundamental Research Funds for the Central Universities(No.06500100).
