Jin Chuanhong, Suenaga Kazu, Iijima Sumio
Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan.
ACS Nano. 2008 Jun;2(6):1275-9. doi: 10.1021/nn800121v.
Catalyst-free inner growth of single-wall carbon nanotubes has been directly realized and monitored by means of in situ high-resolution transmission electron microscopy, with particular attention paid to the evolution of the cap shape. The cap of a carbon nanotube is surprisingly found to be kept closed during the growing/shrinking process, and the cap shape evolves inhomogeneously with a few particular sites growing faster during the growth, while the cap of a carbon nanotube keeps a round shape during the shrinkage process. The closed cap should be specific for noncatalytic growth of carbon nanotubes. We infer, from the results above, the possible atomistic mechanism and how the carbon network can accommodate or release the carbon atoms during the growth/shrinkage of carbon nanotubes.
通过原位高分辨率透射电子显微镜直接实现并监测了单壁碳纳米管的无催化剂内部生长，特别关注了帽状结构的演变。令人惊讶地发现，碳纳米管的帽在生长/收缩过程中保持封闭，帽状结构不均匀地演变，在生长过程中有几个特定部位生长得更快，而碳纳米管的帽在收缩过程中保持圆形。封闭的帽对于碳纳米管的非催化生长应该是特定的。基于上述结果，我们推断了可能的原子机制以及在碳纳米管生长/收缩过程中碳网络如何容纳或释放碳原子。
