第35卷第8期 第35卷第8期 2007年8月
吕晓萌等：TiO2掺杂粉体的溶胶–凝胶和水热合成及其光降解甲醛
· 987 ·Vol. 35，No. 8 August，2007
硅 酸 盐 学 报
JOURNAL OF THE CHINESE CERAMIC SOCIETY
磁性核壳Fe3O4/Ag纳米复合粒子的制备及性能
章桥新，杨丽宁，张佳明2，官建国2，王一龙2 (1. 武汉理工大学机电工程学院；2. 武汉理工大学，材料复合新技术国家重点实验室，武汉 430070)
摘 要：以硅烷偶联剂巯基丙基三甲氧基硅烷作为添加剂，甲醛作为还原剂，在Ag[(NH3)2]+溶液中制备出具有核壳结构的Fe3O4/Ag纳米复合粒子。用X射线衍射、场发射扫描电镜、差热分析、振动样品磁强计和Hall效应测试系统对样品进行了表征。结果表明：Fe3O4/Ag核壳复合粒子粒径为40～60 nm，Ag壳层厚度为10～15 nm，体积电阻率为7.757 3×10–4 ?·cm，饱和磁化强度为26.37 A·m2/kg。
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关键词：磁性核壳；四氧化三铁/银；纳米复合粒子；电磁性能
中图分类号：TQ171.71 文献标识码：A 文章编号：0454–5648(2007)08–0987–04
PREPARATION OF MAGNETIC CORE-SHELL Fe3O4 /Ag NANOPARTICLES AND ITS PROPERTIES
ZHANG Qiaoxin ，YANG Lining，ZHANG Jiaming2，GUAN Jianguo2，WANG Yilong2
(1. School of Mechanical and Electronic Engineering, Wuhan University of Technology; 2. State Key Laboratory of Advanced
Technology for Materials Synthesis and Processing, Wuhan University of
Technology, Wuhan 430070, China)
Abstract: Fe3O4/Ag core-shell nanoparticles were prepared by the reduction of Ag[(NH3)2]+ with formaldehyde as reductant, and mer-capto-propyl-trimethoxy-silane as an additive. The nanocomposite particles were characterized by X-ray diffraction, field-emission- scanning electron microscopy, differential thermal analysis, vibrating sample magnetometry and HL–5 hall effect testing. The results show that the size distributions of the core-shell Fe3O4/Ag nanocomposites averaged 40—60 nm, with a thickness of 10—15 nm of Ag layer. The volume resistivity of the nanocomposites is 7.757 3×10–4 ?·cm and the saturation magnetization is 26.37 A·m2/kg.
Key words: magnetic core-shell; ferroferric oxide/silver; nanocomposite; electromagnetic properties
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With electromagnetic radiation and a leakage of elec-tromagnetic waves seriously increasing, electromagnetic shielding materials were widely used for electromagnetic shielding. With the advantages of light weight and high conductivity, electromagnetic shielding materials based on Ag-coated ceramic particles (mainly SiO2, Al2O3 and TiO2) were extensively used as anti-electromagnetic interference and electromagnetic shielding materials in the aerospace field and other fields.[1–3] The shielding effectiveness of the ceramic composite materials depends only on the conduc-tivity of the coating conductor, such as Ag or Cu, but the shielding effectiveness in the low-frequency field (below 10 MHz) is far less than that in the high-frequency field (above 1 GHz). Fe3O4 has a higher permeability and better shielding effectiveness in the low-frequency field (below 10 MHz).[4] The compounding of magnetic conductors with high conductivity and high-magnetic materials can
收稿日期：2007–02–12。 修改稿收到日期：2007–03–28。 基金项目：国家“863”计划(2006AA03Z461)和国防预研基金计划
(51447020105QT6903)资助项目。
第一作者：章桥新(1961～)，男，教授，硕士研究生导师。
produce wide-frequency electromagnetic shielding materi-als. At present, the research of magnetic compound parti-cles has been focused on Fe3O4/Au, which was mainly applied in the optical and biomedical fields, and due its price, Au is too expensive.[5–7] There has been little re-search of Fe3O4/Ag compound nanoparticles in the bio-medical field,[8–10] and research for the electromagnetic shielding has hardly been reported. Therefore, the core-shell Fe3O4/Ag compound nanoparticles with good magnetic and electric properties were prepared with mer-capto propyl trimethoxy silane (MPTS) as an additive.
1 Experimental procedure
1.1 Synthesis
Raw materials in the test include: magnetite (Fe3O4, with a particle size of 20—30 nm), purchased from East
Received date: 2007–02–12. Approved date: 2007–03–28. First author: ZHANG Qiaoxin (1961—), male, professor. E-mail: zhangqx@whut.edu.cn
磁性核壳Fe_3O_4／Ag纳米复合粒子的制备及性能(英文)
