Dynamically frequency‐tunable and environmentally stable microwave absorbers
Xiao Liu,
Lihong Wu,
Jun Liu,
Haiming Lv,
Pengpeng Mou,
Shaohua Shi,
Lei Yu,
Gengping Wan,
Guizhen Wang
Affiliations
Xiao Liu
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Lihong Wu
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Jun Liu
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Haiming Lv
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Pengpeng Mou
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Shaohua Shi
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Lei Yu
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Gengping Wan
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Guizhen Wang
Key Laboratory of Pico Electron Microscopy of Hainan Province, Center for Advanced Studies in Precision Instruments Hainan University Haikou Hainan China
Abstract The threat to information security from electromagnetic pollution has sparked widespread interest in the development of microwave absorption materials (MAMs). Although considerable progress has been made in high‐performance MAMs, little attention was paid to their absorption frequency regulation to respond to variable input frequencies and their stability and durability to cope with complex environments. Here, a highly compressible polyimide‐packaging carbon nanocoils/carbon foam (PI@CNCs/CF) fabricated by a facile vacuum impregnation method is reported to be used as a dynamically frequency‐tunable and environmentally stable microwave absorber. PI@CNCs/CF exhibits good structural stability and mechanical properties, which allows precise absorption frequency tuning by simply changing its compression ratio. For the first time, the tunable effective absorption bandwidth can cover the whole test frequency band (2−18 GHz) with the broadest effective absorption bandwidth of 10.8 GHz and the minimum reflection loss of −60.5 dB. Moreover, PI@CNCs/CF possesses excellent heat insulation, infrared stealth, self‐cleaning, flame retardant, and acid‐alkali corrosion resistance, which endows it high reliability even under various harsh environments and repeated compression testing. The frequency‐tunable mechanism is elucidated by combining experiment and simulation results, possibly guiding in designing dynamically frequency‐tunable MAMs with good environmental stability in the future.