【摘要】 报道了具有核壳结构的Fe3 O4 聚苯胺磁性纳米微球的合成方法和表征结果 .微球同时具有导电性和磁性能 .在优化的实验条件下 ,可得到饱和磁化强度Ms 为 5 5 .4emu/g ,矫顽力Hc 为 6 2Oe的磁性微球 .微球的导电性随着微球中Fe含量的增加而下降 .微球的磁性能则随着Fe含量的增加而增大 .Fe3 O4 磁流体的粒径和磁性聚苯胺微球的粒径均在纳米量级 .纳米Fe3 O4 粒子能够提高复合物的热性能 .实验表明 ,磁流体和聚苯胺之间可能存在着一定的相互作用 ,但这种相互作用较为复杂 ,难于研究 .更多还原

【Abstract】 The Fe 3O 4 nanoparticles primarily prepared by precipitation oxidation method, and the Fe 3O 4 PANI nanoparticles with core shell structure is synthesized via an in situ polymerization of aniline monomer in an aqueous solution, which contains well dispersed Fe 3O 4 nanoparticles and surfactant NaBS. The particles are almost spherical with diameters ranging from 20～30 nm. These particles are polydisperse and some of them agglomerated due to magneto dipole interactions between particles. TEM micrographs of Fe 3O 4 PANI nanoparticles, which is quite polydispersed. 70%～80% of the Fe 3O 4 PANI particles are ranged from 70～100 nm in diameter. In order to identify the core shell structure of nanoparticles, the Fe 3O 4 PANI powder composite was dissolved with N methyl 2 pyrrolidore, which is a good solvent for PANI, and observed by TEM again. The micrograph was similar to the micrograph of Fe 3O 4 particles. This result indicated Fe 3O 4 PANI nanoparticle was core shell structure. The core is Fe 3O 4 nanoparticles and the shell is composed of PANI. Fe 3O 4 content was found to affect significantly on both conductivity and magnetization of the resulting PANI composites. When 9% Fe 3O 4 was incorporated into PANI, the conductivity of PANI composite was greatly reduced from 5.55×10 -3 ～1.53×10 -4 s/cm. Further increasing of Fe 3O 4 content from 16%～44%, results in slight reduction of the conductivity at room temperature. The decrease in conductivity of Fe 3O 4 PANI composite with increasing Fe 3O 4 content was due to a decrease in the doping degree, assigned as S/N ratio. The S/N ratios decrease from 0.31 to 0.09 with increasing Fe 3O 4 content from 0 to 44 %. The magnetic properties of the Fe 3O 4 PANI nanocomposite depend on the Fe 3O 4 content. Increasing Fe 3O 4 content from 0 to 44 considerably increases both the saturated magnetization (Ms) and the coercive force (Hc) from 0～55.4 emu/g and 0～62 Oe, respectively. Since PANI powder is not magnetic, the magnetic Fe 3O 4 nanoparticles are attributed to the ferromagnetic properties. The magnetic Fe 3O 4 nanoparticles can improve the thermal stability of Fe 3O 4 polyaniline nanocomposites due to interaction between Fe 3O 4 particles and polyaniline chains.更多还原