Cirić-Marjanović Gordana, Dragicević Ljiljana, Milojević Maja, Mojović Milos, Mentus Slavko, Dojcinović Biljana, Marjanović Budimir, Stejskal Jaroslav
Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade, Serbia.
J Phys Chem B. 2009 May 21;113(20):7116-27. doi: 10.1021/jp900096b.
Self-assembled semiconducting, paramagnetic polyaniline nanotubes have been synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate in aqueous medium in the presence of colloidal silica particles of an average diameter approximately 12 nm, without added acid. The electrical conductivity of polyaniline nanotubes/silica nanocomposites is in the range (3.3-4.0)x10(-3) S cm(-1). The presence of paramagnetic polaronic emeraldine salt form of polyaniline and phenazine units in nanocomposites was proved by FTIR, Raman, and EPR spectroscopies. The influence of the initial silica/aniline weight ratio on the morphology of polyaniline/silica nanocomposites was studied by scanning and transmission electron microscopies. Nanocomposites synthesized by using the initial weight ratio silica/aniline<or=0.2 contain polyaniline nanotubes which have a typical outer diameter of 100-250 nm and an inner diameter of 10-80 nm, and nanorods with a diameter of 60-100 nm, accompanied with polyaniline/silica nanogranules, while the nanocomposite synthesized at weight ratio silica/aniline approximately 2 contains polyaniline/silica nanogranules with an average diameter of 35-70 nm. The evolution of molecular and supramolecular structure of polyaniline in the presence of colloidal silica is discussed.
通过在平均直径约为12nm的胶体二氧化硅颗粒存在下，在无添加酸的水性介质中使苯胺与过硫酸铵进行氧化聚合，合成了自组装的半导体、顺磁性聚苯胺纳米管。聚苯胺纳米管/二氧化硅纳米复合材料的电导率在(3.3 - 4.0)×10⁻³ S cm⁻¹范围内。通过傅里叶变换红外光谱(FTIR)、拉曼光谱和电子顺磁共振(EPR)光谱证实了纳米复合材料中存在顺磁性极化子形式的聚苯胺和吩嗪单元。通过扫描电子显微镜和透射电子显微镜研究了初始二氧化硅/苯胺重量比对聚苯胺/二氧化硅纳米复合材料形态的影响。使用初始重量比二氧化硅/苯胺≤0.2合成的纳米复合材料包含典型外径为100 - 250nm、内径为10 - 80nm的聚苯胺纳米管以及直径为60 - 100nm的纳米棒，同时伴有聚苯胺/二氧化硅纳米颗粒，而在二氧化硅/苯胺重量比约为2时合成的纳米复合材料包含平均直径为35 - 70nm的聚苯胺/二氧化硅纳米颗粒。讨论了在胶体二氧化硅存在下聚苯胺分子和超分子结构的演变。
