Microwave absorbers with unique optical and mechanical performance are urgent for complex electromagnetic environment.Here,we demonstrate the mechanically flexible,optically transparent,and microwave-absorbing polyacr...Microwave absorbers with unique optical and mechanical performance are urgent for complex electromagnetic environment.Here,we demonstrate the mechanically flexible,optically transparent,and microwave-absorbing polyacrylamide(PAM)hydrogel,in which the polar water molecules with high polarization contribute to the efficient microwave attenuation,but the binding between water molecules and PAM will slow down the orientation polarization of polar molecules.Meanwhile,the dominated dielectric property of water molecules in PAM hydrogel determines that the molecules displacement in polymer mixture is feasible for manipulating permittivity.Besides,by decreasing temperature,the flexible and transparent hydrogel will switch to rigid and opaque state as the phase conversion between amorphous and polycrystal state.By constructing structures with such hydrogel,the obtained absorber also exhibits the optical and mechanical switchable properties,covering the effective absorption within 5.7-18 GHz.This work provides an effective method to fabricate optically and mechanically manipulable microwave absorbers for intelligent electromagnetic stealth systems.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(No.62101073)Natural Science Foundation of Hunan Province(Nos.2021JJ30154 and 2022JJ40127)+1 种基金Scientific Research Project of Hunan Provincial Education Department(No.21B0557)Development and Reform Commission of Hunan Province 2021 Innovative Research and Development Project(No.10:Preparation and Electromagnetic Properties of Biochar Composites).
文摘Microwave absorbers with unique optical and mechanical performance are urgent for complex electromagnetic environment.Here,we demonstrate the mechanically flexible,optically transparent,and microwave-absorbing polyacrylamide(PAM)hydrogel,in which the polar water molecules with high polarization contribute to the efficient microwave attenuation,but the binding between water molecules and PAM will slow down the orientation polarization of polar molecules.Meanwhile,the dominated dielectric property of water molecules in PAM hydrogel determines that the molecules displacement in polymer mixture is feasible for manipulating permittivity.Besides,by decreasing temperature,the flexible and transparent hydrogel will switch to rigid and opaque state as the phase conversion between amorphous and polycrystal state.By constructing structures with such hydrogel,the obtained absorber also exhibits the optical and mechanical switchable properties,covering the effective absorption within 5.7-18 GHz.This work provides an effective method to fabricate optically and mechanically manipulable microwave absorbers for intelligent electromagnetic stealth systems.
