The advantages of Fe,Ni metals and one-dimensional(1D)carbon materials are combined in this study using a simple method to prepare FeNi/C nanofibers for electromagnetic microwave(EM)absorption.The prepared FeNi/C nano...The advantages of Fe,Ni metals and one-dimensional(1D)carbon materials are combined in this study using a simple method to prepare FeNi/C nanofibers for electromagnetic microwave(EM)absorption.The prepared FeNi/C nanofibers exhibit excellent EM absorption performance under dielectric/magnetic synergistic effect.At a frequency of 13.3 GHz,the minimum reflection loss(RLmin)reaches-57.15 dB,and effective absorption bandwidth(EAB)is as high as 4.0 GHz(12.5-16.5 GHz),with a thickness and filling rate of only 1.6 mm and 30 wt.%,respectively.Analysis shows that the EM absorption performance of FeNi/C nanofibers far exceeds that of single-component nanofibers and pure carbon fibers,and the excellent EM absorption performance is due to its unique microstructure and excellent electromagnetic properties.The FeNi alloy loaded on carbon nanofibers forms rich heterogeneous interfaces,and the three-dimensional(3D)conductive network composed of 1D carbon fibers increases the migration path of electrons.In addition,FeNi alloy,as an impedance regulation factor,strengthens the dielectricity of the carbon matrix while providing multidimensional magnetism,achieving impedance matching.This work is thought to contribute to the promotion of emerging absorbers by providing a novel strategy for the development of new 1D magnetic carbon-based high-performance EM absorbing materials.展开更多
With the miniaturization and integration of electronic devices,devel-oping advanced multifunctional phase change materials(PCMs)inte-grating thermal storage,thermal conduction,and microwave absorption to address elect...With the miniaturization and integration of electronic devices,devel-oping advanced multifunctional phase change materials(PCMs)inte-grating thermal storage,thermal conduction,and microwave absorption to address electromagnetic interference,thermal dissipation,and instantaneous thermal shock is imperative.Herein,we proposed an extensible strategy to synthesize MOF‐derived Co/C‐anchored MoS_(2)‐based PCMs using high‐temperature carbonation of flower‐like MoS_(2) grown in situ by ZIF67 and vacuum impregnation of paraffin.The resulting MoS_(2)@Co/C‐paraffin composite PCMs exhibited good thermal storage density,thermal cycling stability,and long‐term durability.The thermal conductivity of composite PCMs was 44%higher than that of pristine paraffin due to the construction of low interfacial thermal resistance.More attractively,our designed composite PCMs also possessed-57.15 dB minimum reflection loss at 9.2 GHz with a thickness of 3.0 mm,corresponding to an effective absorption bandwidth of 3.86 GHz.The excellent microwave absorption was attributed to the multicomponent synergy of magnetic loss from Co nanoparticles and conductive loss from MOF‐derived carbon layers,and multiple reflection of MoS_(2) nanowrinkle,along with good impedance matching.This study provided a meaningful reference for the widespread application of composite PCMs combining thermal storage,thermal conduction,and microwave absorption in high‐power miniaturized electronic devices.展开更多
基金supported by the Natural Science Foundation of Shandong Province(Nos.ZR2021ME019 and ZR2019BB063).
文摘The advantages of Fe,Ni metals and one-dimensional(1D)carbon materials are combined in this study using a simple method to prepare FeNi/C nanofibers for electromagnetic microwave(EM)absorption.The prepared FeNi/C nanofibers exhibit excellent EM absorption performance under dielectric/magnetic synergistic effect.At a frequency of 13.3 GHz,the minimum reflection loss(RLmin)reaches-57.15 dB,and effective absorption bandwidth(EAB)is as high as 4.0 GHz(12.5-16.5 GHz),with a thickness and filling rate of only 1.6 mm and 30 wt.%,respectively.Analysis shows that the EM absorption performance of FeNi/C nanofibers far exceeds that of single-component nanofibers and pure carbon fibers,and the excellent EM absorption performance is due to its unique microstructure and excellent electromagnetic properties.The FeNi alloy loaded on carbon nanofibers forms rich heterogeneous interfaces,and the three-dimensional(3D)conductive network composed of 1D carbon fibers increases the migration path of electrons.In addition,FeNi alloy,as an impedance regulation factor,strengthens the dielectricity of the carbon matrix while providing multidimensional magnetism,achieving impedance matching.This work is thought to contribute to the promotion of emerging absorbers by providing a novel strategy for the development of new 1D magnetic carbon-based high-performance EM absorbing materials.
基金National Natural Science Foundation of China,Grant/Award Number:51902025。
文摘With the miniaturization and integration of electronic devices,devel-oping advanced multifunctional phase change materials(PCMs)inte-grating thermal storage,thermal conduction,and microwave absorption to address electromagnetic interference,thermal dissipation,and instantaneous thermal shock is imperative.Herein,we proposed an extensible strategy to synthesize MOF‐derived Co/C‐anchored MoS_(2)‐based PCMs using high‐temperature carbonation of flower‐like MoS_(2) grown in situ by ZIF67 and vacuum impregnation of paraffin.The resulting MoS_(2)@Co/C‐paraffin composite PCMs exhibited good thermal storage density,thermal cycling stability,and long‐term durability.The thermal conductivity of composite PCMs was 44%higher than that of pristine paraffin due to the construction of low interfacial thermal resistance.More attractively,our designed composite PCMs also possessed-57.15 dB minimum reflection loss at 9.2 GHz with a thickness of 3.0 mm,corresponding to an effective absorption bandwidth of 3.86 GHz.The excellent microwave absorption was attributed to the multicomponent synergy of magnetic loss from Co nanoparticles and conductive loss from MOF‐derived carbon layers,and multiple reflection of MoS_(2) nanowrinkle,along with good impedance matching.This study provided a meaningful reference for the widespread application of composite PCMs combining thermal storage,thermal conduction,and microwave absorption in high‐power miniaturized electronic devices.
