Carbon nanofibers from polyacrylonitrile and mesophase pitch
Carbon nanofibers from polyacrylonitrile and mesophase pitch
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发表时间：
1999
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通讯作者：
I. Chun;D. Reneker;H. Fong;X. Fang;J. Deitzel;N. B. Tan;K. Kearns
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作者：
I. Chun;D. Reneker;H. Fong;X. Fang;J. Deitzel;N. B. Tan;K. Kearns
以聚丙烯腈和中间相沥青为原料制备了碳纳米纤维。采用稳定化和碳化工艺将初生纳米纤维转化为碳纤维。纳米纤维是任意长度的，尽管已经找到了一种方法来制造长度不到一毫米、具有高纵横比的纳米纤维。典型的碳纳米纤维的直径从100纳米到几微米不等。对数正态分布很好地表示了测得的直径分布。用偏光显微镜、扫描电子显微镜、透射电子显微镜和广角X射线衍射仪对碳纳米纤维进行了观察。纺丝时的中间相沥青纤维是透明的，透射光为红色或橙色，双折射。获得了单个碳纳米纤维的电子衍射图。用广角X射线衍射法测量了中间相沥青基碳纳米纤维的(002)晶面间距。与复合材料中通常使用的碳纤维相比，纳米纤维具有更高的表面积与质量比。碳纳米纤维可用于过滤器、高温反应中的催化剂载体、提高机械性能的复合材料或半导体器件的热管理。碳纤维中的纳米孔是用饱和了水蒸气的氮气制造的。
Carbon nanofibers were produced from both polyacrylonitrile and mesophase pitch. Stabilization and carbonization processes were used to convert as-spun nanofibers to carbon fibers. The nanofibers are arbitrarily long, although a way to make nanofibers less than a millimeter long, with high aspect ratios, was found. The diameters of typical carbon nanofibers are in the range from 100 nanometer to a few microns. A log normal distribution provides a good representation of the measured distribution of diameters. The carbon nanofibers were observed by polarized optical microscopy, scanning electron microscopy, transmission electron microscopy, and wide angle x-ray diffraction. As-spun mesophase pitch fibers are transparent, red or orange in transmitted light, and birefringent. Electron diffraction patterns were obtained from individual carbon nanofibers. The interplane spacing of (002) planes of mesophase pitch based carbon nanofibers was measured using wide angle x-ray diffraction. Nanofibers provide a higher ratio of surface area to mass than carbon fibers ordinarily used in composites. Carbon nanofibers can be useful in filters, as a support for catalysts in high temperature reactions, in composites to improve mechanical properties, or for thermal management in semiconductor devices. Nanopores in carbon fibers were produced using nitrogen gas saturated with water vapor.