Nowadays, multifunctional electromagnetic (EM) wave absorbing aerogels have attracted much attention due to intelligent and wearable features for electronic devices. However, the utilization of these aerogels at elevated temperature is still challenge. Herein, we describe a robust strategy to fabricate architecturally controllable and multifunctional Ti₃C₂T_X MXene/aramid nanofiber (ANF)/polyimide (PI) aerogels with desirable EM wave absorption, adjustable mechanical property, and high thermal insulation. Rational structural design endows the aerogels with an effective absorption bandwidth (EAB) of 4.2 GHz (covering whole X-band) at 250 °C. Exploration of the temperature response over 25–250 °C reveals that the microstructure characters of the aerogels contribute substantially to the EM parameters at elevated temperature, while the in-depth temperature-dependent mechanisms of aerogel EM performance are well studied. Further, through regulating the microstructure, the MXene/ANF/PI aerogels also exhibit tunable mechanical performance (maximum compressive stress of 334.3 KPa at 40% compression) and promising thermal insulation performance (0.029 ± 0.003 W mK⁻¹, closing to air). These multifunctional aerogels light the way to potential application in the EM wave absorption field of flexible devices at elevated temperature.

如今，多功能电磁（EM）波吸收气凝胶由于电子设备的智能和可穿戴特性而备受关注。然而，在高温下使用这些气凝胶仍然是一个挑战。在这里，我们描述了一种稳健的策略来制造结构可控和多功能的 Ti ₃ C ₂ T _X MXene/芳纶纳米纤维(ANF)/聚酰亚胺 (PI) 气凝胶，具有理想的 EM 波吸收、可调节的机械性能和高隔热性。. 合理的结构设计使气凝胶在 250 °C 时的有效吸收带宽 (EAB) 为 4.2 GHz（覆盖整个 X 波段）。对 25-250 °C 温度响应的探索表明，气凝胶的微观结构特征对高温下的 EM 参数有很大贡献，同时深入研究了气凝胶 EM 性能的温度依赖性机制。此外，通过调节微观结构，MXene/ANF/PI 气凝胶还表现出可调节的机械性能（ 40% 压缩时的最大压缩应力为 334.3 KPa）和良好的隔热性能（0.029 ± 0.003 W mK ^-1，接近空气）。这些多功能气凝胶为高温下柔性器件的电磁波吸收领域的潜在应用开辟了道路。