Ultralight microwave absorber with an enhanced absorption performance based on chitosan aerogel

In order to meet practical application, the fabrication and design of lightweight and multifunctional microwave absorbers is challenging. The strategy of this work, is the fabrication of polymer/carbon/mineral MoSe2/RGO/MMTi-Chitosan as a hybrid aerogel via freeze-drying method by introducing the adjusted weight ratio of MoSe2/RGO/MMTi (i = 0, 35, 50, and 75 wt% were named as: m1, m2, m3 and m4, respectively) nanocomposites as filler of chitosan polymer. FESEM confirmed the porous morphology of aerogels at different scales. The microwave absorption measurements showed that, raw chitosan polymer has a weak absorption efficiency. A significant improvement in microwave absorption efficiency was observed by introducing MoSe2/RGO/MMTi filler. MoSe2/RGO/MMT(50%wt)-Chitosan (m3) showed the RLmin of -72 dB with a bandwidth of 3.8 GHz at 2.7 mm. M4 showed the broadest bandwidth at 2.3 mm which covered the entire frequency X and Ku band. The energy conversion and absorption in MoSe2/RGO/MMTi-Chitosan originated from synergetic effect of these factors: high electrical conductivity of MoSe2/RGO, extensive surface of MMT which reduces MoSe2 agglomeration and microporous structure of chitosan. Finite element simulation showed that by covering a PEC (perfect electrical conductor) sphere with 2.3 mm of each composite, the radar cross-section (RCS) reduced to 30–60 dB across the entire frequency band and the scattered far filed reduced 30-35dB.