多孔羰基铁/SiO2/聚吡咯核壳结构复合材料的制备及电磁特性
Synthesis and Electromagnetic Properties of Porous Carbonyl Iron/SiO2/Polypyrrole Core-Shell Structure Composites
作者单位E-mail
谢明达 空军工程大学, 西安 710051  
田晓霞 空军工程大学, 西安 710051
武汉科技大学, 省部共建耐火材料与冶金国家重点实验室, 武汉 430081 
xiaoxiatian@126.com 
屈绍波 空军工程大学, 西安 710051 shaoboqu@126.com 
程花蕾 宝鸡文理学院化学化工系, 宝鸡 721013  
摘要: 首先对羰基铁进行点腐蚀得到多孔羰基铁,然后采用Stöber法和原位聚合法将SiO2和导电高分子聚吡咯包覆在多孔羰基铁表面,制备多孔羰基铁/SiO2/聚吡咯电磁复合吸波材料。采用XRD、SEM、TEM、FT-IR对样品结构、微观形貌进行了表征,在网络分析仪中采用同轴法测试样品电磁参数,并根据传输线理论研究了2~18 GHz微波频段内吡咯含量及涂层厚度对样品吸波性能的影响。实验结果表明:制备的多孔羰基铁/SiO2/聚吡咯复合电磁吸波材料具有核壳结构;随着吡咯加入量的增加,吸波材料吸收峰逐渐向低频方向移动;当涂层厚度为3.5 mm、吡咯加入量为6%(w/w)时,在9.44~17.56 GHz范围内反射率均低于-10 dB,频带宽度为8.12 GHz,损耗反射率达到-23 dB。良好的吸波性能归因于复合物有效的阻抗匹配特性及多重界面极化效应,多孔羰基铁/SiO2/聚吡咯是一种轻质、宽频、强吸收的吸波材料。
关键词: 多孔羰基铁  SiO2过渡层  聚吡咯  核壳结构  电磁特性
基金项目: 省部共建耐火材料与冶金国家重点实验室开放课题(No.201707)和国家自然科学基金(No.21471159,21501007)资助。
Abstract: Porous carbonyl iron powder(CIP) was obtained by means of point erosion and then porous carbonyl iron/SiO2/polypyrrole(porous-CIP/SiO2/PPy) composites were prepared by the Stöber process together with the in-situ polymerization. The phase structure and micro morphology of the composites were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscope(TEM), and Fourier transform infrared spectra(FT-IR). The electromagnetic parameters and microwave absorption properties were measured in 2.0~18.0 GHz by the coaxial method using network analyzer. The effect of the mass ratio of CIP/PPy on electromagnetic properties of the composites was investigated. The measured SEM and TEM show that the porous-CIP particles are firstly coated with SiO2 shell and then graft PPy to form core-shell structures. The absorption loss peak moves to lower frequency with increasing added amount of pyrrole. A minimum reflection loss (RL) of -23 dB and an effective bandwidth(RL below -10 dB) of 8.12 GHz in 9.44~17.56 GHz are obtained for coating thickness of 3.5 mm and 6%(w/w) pyrrole, which can be attributed to the effective impedance match and multiple interfacial polarizations. Owing to the low density and high absorption, the porous-CIP/SiO2/PPy composite can be a promising candidate as lightweight, efficient microwave absorbents.
Keywords: porous carbonyl iron powder  SiO2 layer  polypyrrole  core-shell structure  electromagnetic properties
投稿时间:2018-01-01 修订日期:2018-05-21
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谢明达,田晓霞,屈绍波,程花蕾.多孔羰基铁/SiO2/聚吡咯核壳结构复合材料的制备及电磁特性[J].无机化学学报,2018,34(7):1261-1270.
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