Magnetic iongel/carbon nanotube composites for ultra-broadband electromagnetic wave absorption

Organic magnets possess broad application prospects in electromagnetic wave (EW) absorbing materials (EAMs) due to their special electromagnetic properties, lightweight nature and good compatibility. Thus, in this paper, an innovative organic magnet, magnetic iongel (C12IMSO3[FeCl4]), was successfully fabricated through the self-assembly of an alkyl long-chain imidazolium zwitterion (C12IMSO3) and a magnetic ionic liquid (Bmim[FeCl4]). EWs were absorbed via various attenuating routes in C12IMSO3[FeCl4], such as ionic conductive, polarization and magnetic loss. The minimum reflect loss (RLmin) and effective absorption bandwidth (EAB) of the C12IMSO3[FeCl4] EW absorber could reach −35 dB and 1.8 GHz, respectively. After being combined with CNTs and further introducing strong electric conductive loss, the C12IMSO3[FeCl4]/CNT composition showed more advanced EW absorption properties, especially in terms of the EAB; C12IMSO3[FeCl4]/CNT achieved an EAB of 7.44 GHz at a small thickness of 2.2 mm. The ultra-broadband EW absorption performance of the C12IMSO3[FeCl4]/CNT composite transcends many reported inorganic magnetic EW absorbing composites, providing a new approach to broadband EW absorbing materials.