Lightweight, Flexible, and Thermal Insulating Carbon/SiO₂@CNTs Composite Aerogel for High‐Efficiency Microwave Absorption

AbstractA complex electromagnetic environment is a formidable challenge in national defense areas. Microwave‐absorbing materials are considered as a strategy to tackle this challenge. In this work, lightweight, flexible, and thermal insulating Carbon/SiO2@CNTs (CSC) aerogel is successfully prepared coupled with outstanding microwave absorbing performance, through freeze‐drying and high‐temperature annealing techniques. The CSC aerogel shows a strong reflection loss (−55.16 dB) as well as wide effective absorbing bandwidth (8.5 GHz) in 2–18 GHz. It also retains good microwave absorption properties under tension and compression. Radar cross‐sectional (RCS) simulation result demonstrates the CSC processing a strong reduction ability of RCS compared with a metal plate. Further exploration shows amazing flexibility and good thermal insulation properties of CSC. The successful preparation of this composite aerogel provides a broad prospect for the design of microwave‐absorbing materials.