Cross-Dimensional Assembly of MXene/SiO2/KNF Composite Aerogels for Radar and Infrared Stealth

Radar/infrared-compatible stealth materials enhance survivability by reducing the radar cross-section and suppressing infrared signatures. However, the significant differences in frequency characteristics across electromagnetic wavebands present challenges in optimizing cross-band electromagnetic response. To address this issue, we propose a cross-dimensional integration strategy. Zero-dimensional (0D) SiO2 aerogel particles with low thermal conductivity act as infrared radiation modulation component and two-dimensional (2D) Ti3C2Tx MXene nanosheets with high electronic conductivity function as the electromagnetic wave-responsive component; the 0D and 2D functional components are directionally anchored onto one-dimensional (1D) Kevlar nanofiber (KNF) surfaces through hydrogen bonding, cooperatively constructing a monolithic interconnected network structure. The as-designed MXene/SiO2/KNF aerogel (MSKA) has a bionic-inspired “root-soil” structure, which effectively reduces infrared radiation intensity through multiple scattering effects and enhances electromagnetic wave attenuation by optimizing spatial impedance matching and introducing multiple loss mechanisms. The MSKA exhibits excellent microwave absorption, achieving a minimum reflection loss of -64.69 dB at a thickness of 1.83 mm, with an effective absorption bandwidth (RL < -10 dB) covering 7.2 GHz; thermal testing reveals a surface temperature difference of 123.1 °C under a 175 °C heat source, indicating a significant reduction in infrared radiation intensity. This assembly strategy, enabling independent regulation of electromagnetic loss and thermal conduction through multidimensional integration, provides new insights for developing lightweight, high-performance, and multispectral stealth materials.