Compression strain-dependent tubular carbon nanofibers/graphene aerogel absorber with ultrabroad absorption band

Abstract

The compressive strain-dependent microwave dissipation behavior gives aerogel the great possibility of achieving the broad-band absorption. However, there are few investigations that focus on the close association between the compression strain and microwave attenuation performance, and it still remains a vast challenge to construct the elastic microwave absorbers with the good mechanical durability. Herein, by attaching the intertwined tubular carbon nanofibers (TCNFs) to graphene skeleton, lightweight elastic TCNFs/graphene aerogel (TGA) with the anisotropic architecture was formed via chemical cross-linking, freeze-drying and subsequent reduction. When the compression strain is 60% along the vertical direction, the hybrid aerogel is endowed with the satisfactory impedance matching and enhanced conduction loss, originating from the dense cellular configuration. Thus, it harvests the most prominent microwave consumption of a minimum reflection loss (RLmin) value of −46.1 dB and an effective absorption bandwidth (EAB) value of 7.1 GHz. By tuning the compressive strain, an ultrabroad EAB of 11.5 GHz is realized. Besides, the other favorable properties including fatigue resistance, heat insulating and water stability are also acquired. These intriguing features make the hybrid aerogel stand out among numerous absorbers. This study is instructive to develop multifunctional microwave absorbing materials for matching well with the practical environment.