Department of Chemistry & Biochemistry and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095-1569, USA.
ACS Nano. 2010 Sep 28;4(9):5193-202. doi: 10.1021/nn101378p.
Water-dispersible polypyrrole nanospheres with diameters of less than 100 nm were synthesized in high yield without any templates, surfactants, or functional dopants by the introduction of 2,4-diaminodiphenylamine as an initiator into a reaction mixture of pyrrole monomer, oxidant, and acid. The initiator plays a critical role in tailoring the nanostructures of polypyrrole. 2,4-Diaminodiphenylamine interacts with acid to form cations, which combine with various anions to self-assemble resulting in different size nanomicelles. These nanomicelles, stabilized by initiator molecules, act as templates to encapsulate pyrrole and oxidant leading to the formation of nanospheres during polymerization. When smaller acids are used, smaller diameter sphere-like polypyrrole nanostructures are obtained. The as-synthesized polypyrrole nanospheres can then be used to fabricate highly conducting nitrogen-doped carbon nanospheres with controllable sizes of 50-220 nm with monodispersities up to 95% after pyrolysis. The size of the carbon nanospheres decreases by 20-30 nm due to carbonization when compared to the original polymer nanospheres. The molecular structures, morphologies, and electrical properties along with the formation mechanism of the polypyrrole and carbon nanospheres are discussed.
在没有任何模板、表面活性剂或功能掺杂剂的情况下，通过将 2,4-二氨基二苯醚作为引发剂引入吡咯单体、氧化剂和酸的反应混合物中，成功地合成了直径小于 100nm 的水散性聚吡咯纳米球，产率很高。引发剂在调节聚吡咯的纳米结构方面起着关键作用。2,4-二氨基二苯醚与酸相互作用形成阳离子，与各种阴离子结合进行自组装，从而形成不同尺寸的纳米胶束。这些由引发剂分子稳定的纳米胶束作为模板，在聚合过程中包裹吡咯和氧化剂，从而形成纳米球。当使用较小的酸时，会得到直径较小的类球形聚吡咯纳米结构。合成的聚吡咯纳米球可以进一步用于制备高导电性氮掺杂碳纳米球，其尺寸可控，为 50-220nm，经过热解后可达 95%的单分散性。与原始聚合物纳米球相比，碳纳米球的尺寸由于碳化而减小了 20-30nm。讨论了聚吡咯和碳纳米球的分子结构、形态和电性能以及形成机制。
