Tailorable effective microwave absorption bandwidth of chitosan-derived carbon-based aerogel under different compression

Abstract

Confronted with ever-increasing electromagnetic radiation problems, developing microwave absorbing materials with tunable effective absorption bandwidth (EAB) is in high demand. In this work, chitosan-derived carbon-based aerogel was synthesized by unidirectional freeze-drying and the following high-temperature carbonization process. The dielectric-magnetic coupling effect was facilitated by the construction of the 3D conductive network, along with the decoration of the Co nanoparticles and the doping of heteroatoms within the carbon-based framework. Therefore, the aerogel achieved minimum reflection loss intensity of -44.30 dB at 5.20 GHz when carbonizing the precursor at 800 °C. More significantly, the strain-responsive properties of the aerogel endows it with tailorable electromagnetic response behaviors, thereby controlling the effective absorption bandwidth covering from X band to Ku band. This work paves the way for designing next-generation microwave absorption materials with tunable microwave absorption bandwidth, catering to stringent practical requirements prospectively.