乳液聚合条件对纳米Fe_3O_4/导电聚苯胺介电常数的影响

Effect of Emulsion Polymerization Conditions on the Permittivities of Fe_3O_4/Conductive Polyaniline Nanoparticles

以十二烷基苯磺酸(DBSA)为乳化剂和掺杂剂,过硫酸铵(APS)为氧化剂,采用乳液聚合的方法合成了导电聚苯胺包覆磁性四氧化三铁的纳米核-壳复合材料。利用3 cm波导式测量线法分别研究了聚合反应中Fe3O4的含量、DBSA和APS与苯胺的相对含量对复合材料介电常数(ε′,ε″)的影响。测量结果表明,Fe3O4的大量加入会提高复合材料的介电损耗ε;″DBSA和APS的加入量会对导电聚苯胺的共轭结构和导电性产生影响,从而改变复合材料的ε′和ε″。

Electrically conducting polyaniline （PANI） -magnetic oxide （Fe3O4） composites with electrical and ferromagnetic behaviors were synthesized by the way of emulsion polymerization in the presence of dodecyl benzene sulfonic acid （DBSA） as the surfactant and dopant and ammonium persulfate （APS） as the oxidant. The permittivities of Fe3O4/DBSA-PANI nanocomposites with core-shell structure were studied by varying the contents of Fe3O4, DBSA and APS in the polymerization. The results show that the massive Fe3O4 can improve the dielectric loss of the composites and have a higher complex permittivity, the contents of DBSA and APS have the strong influences on the structure and conductivity of the composites and therefore can influence the dielectric loss complexly. The different dissipative mechanisms were discussed to explain the varieties.