NiFe2O4/polypyrrole(NiFe2O4/PPy)nanocomposites are prepared by a simple surface-initiated polymer-ization method and demonstrate negative permittivity in the low frequency regions.These nanocompos-ites also exhibit significantly enhanced electromagnetic wave(EMW)absorption property in the high frequency regions.Compared with pure PPy,the enhanced negative permittivity is observed in the NiFe2O4/PPy nanocomposites with a NiFe2O4 loading of 5.0,10.0,20.0 and 40.0 wt％,indicating the for-mation of metal-like electrical conducting network in NiFe2O4/PPy nanocomposites.Moreover,the neg-ative permittivity could be tuned by changing the NiFe2O4 loading.The minimum reflection loss(RL)of-40.8 dB is observed in the 40.0 wt％NiFe2O4/PPy composites with a thickness of only 1.9 mm.The effective absorption bandwidth below-10.0 and-20.0 dB reaches 6.08 and 2.08 GHz,respectively.The enhanced EMW absorption performance benefits from the improved independence matching,EMW at-tenuation capacity,and synergistic effects of conduction loss,dielectric loss(interfacial and dipole polar-izations)and magnetic loss(exchange and natural resonances).This research work provides a guidance for the fabrication of nanocomposites with an excellent EMW absorption.

Jiang Guo;Xu Li;Zhuoran Chen;Jianfeng Zhu;Xianmin Mai;Renbo Wei;Kai Sun;Hu Liu;Yunxia Chen;Nithesh Naik;Zhanhu Guo

School of Materials Science and Engineering,Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials,Shaanxi University of Science&Technology,Xi'an 710021,China;School of Urban Planning and Architecture,Southwest Minzu University,Chengdu 610041,China;School of Chemical Engineering,Northwest University,Xi'an 710069,China;College of Ocean Science and Engineering,Shanghai Maritime University,Shanghai,201306,China;Key Laboratory of Materials Processing and Mold(Zhengzhou University),Ministry of Education,National Engineering Research Center for Advanced Polymer Processing Technology,Zhengzhou University,Zhengzhou,450001,China;School of Mechanical Engineering,Shanghai Dianji University,Shanghai,201306,China;Department of Mechanical&Manufacturing Engineering,Manipal Institute of Technology,Manipal Academy of Higher Education,Manipal 576104,Karnataka,India;Integrated Composites Laboratory(ICL),Department of Chemical&Biomolecular Engineering,University of Tennessee,Knoxville,TN,37996,USA

材料科学技术（英文版）

[1]Jiang Guo;Xu Li;Zhuoran Chen;Jianfeng Zhu;Xianmin Mai;Renbo Wei;Kai Sun;Hu Liu;Yunxia Chen;Nithesh Naik;Zhanhu Guo-.Magnetic NiFe2O4/Polypyrrole nanocomposites with enhanced electromagnetic wave absorption)[J].材料科学技术（英文版）,2022(13):64-72

tenuation

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