Core-Shell Carbon-Ceramic Fibrous Aerogel Derived from Aramid-Polysilsesquioxane for Broadband Electromagnetic Wave Absorption

Abstract

Carbon-ceramic composites demonstrate exceptional promise for microwave absorption in extreme environments. In this study, a hierarchical carbon-ceramic fibrous aerogel (CCFA) was synthesized via the pyrolysis of bridged polysilsesquioxane coated aramid nanofiber aerogel. The resulting material features interconnected networks and a core-shell skeleton, which establish a dual-level impedance gradient. This unique architecture optimizes surface impedance matching between amorphous carbon and air, facilitating the penetration of incident electromagnetic waves into the ceramic-confined carbon aerogel. The synergistic coexistence of amorphous carbon and silicon oxycarbonitride ceramic phases enhances interfacial effects, amplifying dielectric polarization loss. Consequently, the CCFA achieves a minimum reflection loss of −55.66 dB and a wide effective absorption bandwidth of 8.24 GHz. Furthermore, the aerogel exhibits good thermal insulation and flame-retardant properties, critical for extreme-environment applications. This work presents an effective multilevel structural design and heterointerface engineering strategy for advancing carbon-ceramic composites in high-performance microwave absorption under demanding conditions.