Chemical Engineering Journal 546 (2026) 180386

Keywords: Aramid nanofiber ,Carbon nanotube ,Waxberry-like pore structure ,Aerogel/honeycomb metamaterial ,Electromagnetic wave absorption

Porous aerogels have emerged as promising candidates for lightweight electromagnetic wave absorption (EMWA) materials, yet their practical performance and engineering deployment are severely constrained by three long-standing bottlenecks: the inherent trade-off between interfacial impedance matching and internal electromagnetic dissipation, the strong angular dependence of EMWA performance, and the insufficient mechanical load-bearing capability. Herein, we developed a novel dot-matrix cold-source ice-templating technique in conjunction with honeycomb skeleton reinforcement to fabricate waxberry-like gradient porous aerogel/ honeycomb metamaterials (WGPA/H). The influences of critical structural parameters, including aerogel pore structure and honeycomb cell size, were systematically investigated. The optimal WGPA/H delivers an exceptional minimum reflection loss (RL_min) of 78.5 dB and an ultrabroad effective absorption bandwidth (EAB) of  12.4 GHz. More notably, WGPA/H retains a stable ultrabroad EAB at oblique incidence angles from 5^◦ to 60^◦, demonstrating excellent angle-insensitive EMWA behavior. This outstanding comprehensive EMWA performance is attributed to the synergistic coupling effect between the unique waxberry-like gradient porous structure and the periodic honeycomb array. Furthermore, WGPA/H integrates high thermostability and a compressive strength up to 4.1 MPa, fully satisfying the service requirements of complex high-temperature and high-loading scenarios. The resultant WGPA/H well preserves the intrinsic lightweight characteristic of aerogels, breaks the trade-off between impedance matching and electromagnetic loss, realizes wide-angle EMWA stability, and simultaneously achieves significantly enhanced mechanical load-bearing performance. This work provides a new structural design strategy for multifunctional EMWA devices, facilitating their practical engineering applications.

Anping Wang ,Zhichun Zhang ,Zibo Li ,Yanju Liu ,Jinsong Leng

Honeycomb-reinforced gradient carbon nanotube/aramid nanofiber aerogel metamaterial with excellent electromagnetic wave absorption and load-bearing performance.pdf