Ding Feng, Harutyunyan Avetik R, Yakobson Boris I
Department of Mechanical Engineering and Materials Science, and Department of Chemistry, Rice University, Houston, TX 77005, USA.
Proc Natl Acad Sci U S A. 2009 Feb 24;106(8):2506-9. doi: 10.1073/pnas.0811946106. Epub 2009 Feb 6.
The periodic makeup of carbon nanotubes suggests that their formation should obey the principles established for crystals. Nevertheless, this important connection remained elusive for decades and no theoretical regularities in the rates and product type distribution have been found. Here we contend that any nanotube can be viewed as having a screw dislocation along the axis. Consequently, its growth rate is shown to be proportional to the Burgers vector of such dislocation and therefore to the chiral angle of the tube. This is corroborated by the ab initio energy calculations, and agrees surprisingly well with diverse experimental measurements, which shows that the revealed kinetic mechanism and the deduced predictions are remarkably robust across the broad base of factual data.
碳纳米管的周期性结构表明，它们的形成应遵循晶体所确立的原理。然而，这一重要联系几十年来一直难以捉摸，且尚未发现速率和产物类型分布方面的理论规律。在这里，我们认为任何纳米管都可视为沿轴具有一个螺旋位错。因此，其生长速率与这种位错的柏氏矢量成正比，进而与碳纳米管的手性角成正比。这一点得到了从头算能量计算的证实，并且与各种实验测量结果惊人地吻合，这表明所揭示的动力学机制和推导的预测在广泛的实际数据基础上具有显著的稳健性。
