Deck Christian P, Vecchio Kenneth S
Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Group, University of California, San Diego, La Jolla, California 92093-0411, USA.
J Phys Chem B. 2005 Jun 30;109(25):12353-7. doi: 10.1021/jp050417x.
Layered structures of well-aligned carbon nanotubes were grown using three variations of vapor-phase chemical vapor deposition growth processes. The reactants (typically ferrocene and benzene) were introduced either directly to a heated furnace or carried into the furnace by evaporation or spray pyrolysis in an argon flow. Thick mats of densely packed, well-aligned nanotubes were produced when the reactants were continuously introduced to the reaction; however, when the reactant flow was interrupted, the pauses allowed growth to stop and then restart as a new layer. These pauses were achieved by either completely stopping the reactant flow for a given time or by modifying the dispensing system to introduce the reactants in discrete drops. Time intervals between drops were varied between 20 s and 120 s, with distinct layers observed for pauses of 30 s or greater. The best results were achieved when drops of a catalyst-rich solution were alternated with drops of pure benzene. Layers were grown with thicknesses ranging from several microns to several hundred microns, and structures were grown with well over 100 layers.
使用气相化学气相沉积生长过程的三种变体生长了排列良好的碳纳米管的层状结构。反应物（通常是二茂铁和苯）要么直接引入加热炉中，要么通过在氩气流中蒸发或喷雾热解带入炉中。当反应物连续引入反应时，会产生由密集排列、排列良好的纳米管组成的厚垫；然而，当反应物流动中断时，停顿会使生长停止，然后作为新层重新开始。这些停顿可以通过在给定时间完全停止反应物流动，或者通过修改分配系统以离散液滴的形式引入反应物来实现。液滴之间的时间间隔在20秒到120秒之间变化，停顿时间为30秒或更长时可观察到明显的层。当富含催化剂的溶液液滴与纯苯液滴交替时，可获得最佳结果。生长的层厚度从几微米到几百微米不等，生长的结构有超过100层。
