Composite aerogels composed of reduced graphene oxide (RGO), single-walled carbon nanotubes (SWNTs), and polyimide (PI) with an oriented porous structure exhibit flexible, high-performance microwave absorption and a tunable porosity. The polarization relaxation time is varied by adjusting the heat treatment temperature to achieve ultra-broadband microwave absorption at lower thicknesses. SWNTs contribute to the control of aerogel morphology and significantly improve its mechanical toughness. The prepared aerogel has a bulk density of 9.13 mg/cm³ and excellent absorption properties with a minimum absorption peak of −64.5 dB and an effective absorption bandwidth (EAB) of 9.14 GHz. Through experimental comparison and time-domain finite integration calculation, the effect of oriented porous structure on the electromagnetic loss mechanism and performance was elucidated, which can be used for porous wave-absorbing materials. At the same time, the light and flexible PGS composite aerogel fabric is also remarkably flexible, and its excellent mechanical and thermal insulation properties are attributed to its unique orientated microchannel structure. This low-cost, simple and high-performance approach will greatly simplify the application of multifunctional microwave-absorbing materials in wearable and other extreme conditions, including high-temperature environments.

To improve the synergistic effect between dielectric and magnetic loss is a practical and effective way in optimizing electromagnetic wave absorbing materials. The composites of metal particles and carbon ligands derived from metal organic frameworks have gained wide attention. In this study, Co particles and multiwalled carbon nanotubes (CNT) were successfully synthesized covering the surface of silicon carbide (SiC) fibers, and the morphology, interfaces and electromagnetic wave absorption performance were explored. For sample SiC@Co/CNT, the minimum reflection loss value can reach –70.22 dB at 11.21 GHz with the thickness of 2.12 mm. The effective absorbing bandwidth can reach up to 6.03 GHz with the thickness of 1.71 mm, which covers the entire Ku band. It brings more interfaces between Co particles and CNTs as well as SiC fibers and Co/C nanosheets. The interfacial polarization has been hugely enhanced, and the microwave absorbing properties have been improved. This article reports on the impedance matching of magnetic and non-magnetic components and the heterointerface engineering, which can be effective strategy and inspiration to illustrate the relationship between components, structures and functions of electromagnetic wave absorbing materials.