Functional–Structural Integrated Aramid Nanofiber-based Honeycomb Materials with Ultrahigh Strength and Multi-Functionalities

Multifunctional microwave-absorbing (MA) honeycombs are in urgent demand both in civil and military fields, while they often suffer from great limitations due to the complicated preparation process, inferior strength, and the susceptible peeling off of the absorbent coatings. Herein, we develop a straightforward strategy of assembly of aramid nanofibers (ANFs) and MXene nanosheets to honeycombs, obtaining a functional–structural integrated microwave absorption aramid honeycomb (MAAH). Benefiting from the robust and integrated cell nodes and dense network structure, the compressive strength and toughness of ANF honeycomb can reach up to 18.6 MPa and 2.0 MJ m−3, respectively, which is 6 times and 25 times higher than that of commercial honeycomb. More importantly, the synergistic effect of the unique three-dimensional (3D) conductive network formed by uniformly distributed MXene and the hierarchical structure of the honeycomb endow it with superior wave-absorbing performance, which exhibits a minimum reflection loss (RLmin) of −38.5 dB at a thickness of only 1.9 mm, and covering almost the entire X-band bandwidth. Additionally, MAAH presents exceptional infrared thermal stealth, sound absorption performance, and real-time monitoring of structural integrity. Therefore, these impressive multi-functionalities of MAAH with outstanding wave-absorbing performance, ultrahigh strength, along with the straightforward and easy-to-scalable and recyclable manufacturing technique, demonstrating promising perspectives of the MAAH materials in aerospace and military fields.