Fabrication of ultrafine carbon fibers possessing a nanoporous structure from electrospun polyvinyl alcohol fibers containing silica nanoparticles
Fabrication of ultrafine carbon fibers possessing a nanoporous structure from electrospun polyvinyl alcohol fibers containing silica nanoparticles
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由含有二氧化硅纳米颗粒的电纺聚乙烯醇纤维制备具有纳米孔结构的超细碳纤维
DOI：
10.1155/2014/487943
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发表时间：
2014
影响因子：
--
通讯作者：
Masahito Taya
中科院分区：
文献类型：
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作者：
Koichi Sawada;Shinji Sakai;Masahito Taya
以聚乙烯醇、CoCl2、纳米二氧化硅和N，N-二甲基甲酰胺为原料，采用模板法制备了直径约为500 nm的纳米二氧化硅纤维。在空气中进行热处理，在甲醇蒸气中进行5 h以上的化学气相沉积反应，得到了黑色的导电纤维。透射电子显微镜分析表明，去除二氧化硅后的纤维具有由直径为15 nm的二氧化硅纳米颗粒组成的多孔结构。X-射线能谱分析结合透射电子显微镜证实，在80℃条件下，氢氧化钠处理可以脱除纤维中的二氧化硅。脱硅后纤维的总比表面积和总孔体积分别为318cm2/g和1.67cm3/g。经氮气吸附测试后，纤维的总比表面积和总孔体积分别为318cm2/g和1.67cm3/g。经氢氧化钠处理的聚丙烯腈纤维的方块电阻率为35.1~477Ω/-，与文献报道的80 0℃碳化后的方块电阻率相比，其方块电阻率较高。
Ultrafine carbon fibers with a nanoporous structure were fabricated by the template method using silica nanoparticles (NPs) embedded in fibers of approximate diameter 500 nm, electrospun from an aqueous solution of polyvinyl alcohol, CoCl2, silica NPs, andN,N-dimethylformamide. Black, conductive fibers were obtained by heat treatment in air and a chemical vapor deposition reaction under methanol vapor for more than 5 h. Transmission electron microscopy (TEM) demonstrated that the fabricated fibers after silica removal had a porous structure originating from 15 nm diameter silica NPs. Energy dispersive X‐ray analysis combined with TEM confirmed the removal of silica from the fibers by NaOH treatment at 80°C. Total surface area and total pore volume of the fibers after silica removal, determined by nitrogen adsorption measurement, were 318 m2/g and 1.67 cm3/g, respectively. The sheet resistivities of the fabricated fibers were 35.1–477 Ω/□, which were relatively high, compared with that reported for polyacrylonitrile‐based fibers carbonized at 800°C. D and G bands detected in the Raman spectrum of the NaOH‐treated fibers showed that the prepared carbon fibers were more crystalline than natural carbonaceous materials.