实际上这些束状纤维是由许多单壁或者多壁纳米炭管组成的[23]。图 5(a) 和5(b)是块状产物的SEM和TEM形貌。从SEM图中可以看出块状产物也非常纯净。纤维直径分布比较均一,而且大部分纤维可以观察到中空管的存在,纤维的表面也非常光滑。
用改进的流动催化剂法制备VGCNF不仅设备简单,而且能半连续或连续生产,制备的VGCNF具有直径分布比较均匀、产品纯度高等优点,目前正在深入研究该方法的放大技术。
6 小结
VGCNF是一种十分独特的纳米炭材料,具有许多与众不同的特性,如非常小的尺寸、独特的电学性能、特别优良的力学性能及吸附与催化特性。VGCNF具有十分广阔的应用前景,对其进行广泛而深入的基础和应用研究,具有十分重要的科学意义。
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