Fe_3O_4的含量对纳米磁性导电聚苯胺电磁参数的影响

Effects of the Fe_3O_4 Content on the Electromagnetic Parameters of Magnetic and Conductive Polyaniline Nanoparticles

利用乳液聚合的方法,采用十二烷基苯磺酸(DBSA)为乳化剂和掺杂剂,过硫酸铵(APS)为氧化剂合成了一种具有电磁波吸收能力的导电、导磁复合材料。TEM、SEM、FT-IR和XRD的微观结构分析表明:合成了具有核-壳包覆结构的复合材料,以磁性的Fe3O4作为内核,以DBSA掺杂的聚苯胺包覆在核外形成导电的外壳,粒径在100nm左右;利用3cm波导式测量线法研究了聚合反应中Fe3O4与苯胺的相对含量对复合材料的介电常数和磁导率的影响,分析结果表明:Fe3O4的加入能够在提高复合材料磁损耗的同时,提高其介电损耗,磁导率的虚部随着Fe3O4加入量的增多而增大,而介电常数的虚部随着Fe3O4加入量的增多先减小后增大,当Fe3O4的加入量为40%时,其磁导率虚部在4GHz处到达了最大值0.85,介电常数虚部在2GHz处达到了最大值9.62。

Electric conductive and magnetic permeable nanocomposites with electromagnetic wave absorbing property were synthesized by emulsion polymerization with dodecyl benzene sulfonic acid （DBSA） as the emulsifier and dopant and ammonium persulfate （APS） as the oxidant. The microstructures of the synthesized nanocomposites were characterized by means of TEM, SEM, FT-IR and XRD. The results indicate that the synthesized Fe3O4/PANI/DBSA nanocomposites possess the core-shell structure with magnetic oxide （Fe3O4） as core and conducting polyaniline （PANI） doped by DBSA as shell, the average diameter of the Fe3O4- /PANI/DBSA nanocomposites is about 100 nm The effects of relative content of Fe3O4 and aniline on the permittivity （ε＇, ε＂） and permeability （μ＇, μ＂） of the nanocomposites were studied by the 3 cm waveguide measurement line method. The results show that the magnetic and dielectric losses of the nanocomposites are improved by Fe3O4, and the imaginary part of permeability（μ＂） increases with increasing the Fe3O4 content, while the imaginary part of permittivity （ε＂） decreases at first and then increases with the increase of the Fe3O4 content. The nanocomposites with Fe3O4 content of 40% have the maximum μ＂ of 0.85 at 4 GHz and maximum ε＂ of 9.62 at 2GHz.