Achieving optimal electromagnetic properties in composites requires fine-tuning of microstructure and composition,presenting both practical value and fundamental challenges.Through precisely controlled carbonization o...Achieving optimal electromagnetic properties in composites requires fine-tuning of microstructure and composition,presenting both practical value and fundamental challenges.Through precisely controlled carbonization of polymer-coated Fe_(3)O_(4)@SiO_(2)assembled units,this work elucidates the phase transition-mediated enhancement of electromagnetic wave absorption properties.Raspberry-like C/Fe_(3)O_(4)@SiO_(2)@DC magnetic microspheres are fabricated through a multi-step process involving bubble-assisted hydrothermal growth,silica coating,phosphonitrile polymerization,resin encapsulation,and controlled carbonization.The controlled carbonization temperature-mediated phase transformation from Fe_(3)O_(4)to Fe_(2)SiO_(4)within the microspheres serves to fine-tune both electromagnetic parameters and impedance matching behavior.The C/Fe_(3)O_(4)@Fe_(2)SiO_(4)@DC microspheres carbonized at 700℃exhibit exceptional electromagnetic wave absorption performance,attributed to:(i)the heterogeneous interfaces between dual-phase components,and(ii)the synergistic dielectric-magnetic loss mechanism.The optimized composite demonstrates exceptional microwave absorption performance,achieving a minimum reflection loss(RLmin)of−17.86 dB and an effective absorption bandwidth(EAB)of 6.03 GHz(11.5–17.5 GHz)at an optimal thickness of 2.2 mm.The synergistic combination of tailored composition,optimized interfaces,and controlled defects enables unprecedented EM wave attenuation,providing a blueprint for high-efficiency broadband electromagnetic wave absorbing materials.展开更多
基金supported by the National Natural Science Foundation of China(22375166,22101229)Natural Science Basic Research Program of Shaanxi(2024JC-JCQN-44)。
文摘Achieving optimal electromagnetic properties in composites requires fine-tuning of microstructure and composition,presenting both practical value and fundamental challenges.Through precisely controlled carbonization of polymer-coated Fe_(3)O_(4)@SiO_(2)assembled units,this work elucidates the phase transition-mediated enhancement of electromagnetic wave absorption properties.Raspberry-like C/Fe_(3)O_(4)@SiO_(2)@DC magnetic microspheres are fabricated through a multi-step process involving bubble-assisted hydrothermal growth,silica coating,phosphonitrile polymerization,resin encapsulation,and controlled carbonization.The controlled carbonization temperature-mediated phase transformation from Fe_(3)O_(4)to Fe_(2)SiO_(4)within the microspheres serves to fine-tune both electromagnetic parameters and impedance matching behavior.The C/Fe_(3)O_(4)@Fe_(2)SiO_(4)@DC microspheres carbonized at 700℃exhibit exceptional electromagnetic wave absorption performance,attributed to:(i)the heterogeneous interfaces between dual-phase components,and(ii)the synergistic dielectric-magnetic loss mechanism.The optimized composite demonstrates exceptional microwave absorption performance,achieving a minimum reflection loss(RLmin)of−17.86 dB and an effective absorption bandwidth(EAB)of 6.03 GHz(11.5–17.5 GHz)at an optimal thickness of 2.2 mm.The synergistic combination of tailored composition,optimized interfaces,and controlled defects enables unprecedented EM wave attenuation,providing a blueprint for high-efficiency broadband electromagnetic wave absorbing materials.
