Dell'Acqua-Bellavitis Ludovico M, Ballard Jake D, Vajtai Robert, Ajayan Pulickel M, Siegel Richard W
Department of Engineering Science, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, USA.
J Nanosci Nanotechnol. 2007 Jul;7(7):2335-42. doi: 10.1166/jnn.2007.447.
Arrays of catalytically-grown multi-wall carbon nanotubes were grown using identical conditions in a chemical vapor deposition environment, but cooled at different cooling rates, to identify the influence of cooling rate on the structural properties of the nanotube at the catalyst-wall interface. Ex-situ transmission electron microscopy led to the identification of twist, twin, and tilt domain boundaries in all samples irrespective of cooling rate. In addition, the relative position of twist, twin, and tilt domain boundaries in nanotubes cooled at different rates was maintained uniformly across all samples cooled at different rates. The results are interpreted in light of the concurrence of base- and tip-growth for the catalytic synthesis of nanotubes, suggesting a rather steady position occupied by the domain boundaries coupled to the catalytic particles.
在化学气相沉积环境中，使用相同条件生长催化生长的多壁碳纳米管阵列，但以不同的冷却速率进行冷却，以确定冷却速率对催化剂 - 管壁界面处纳米管结构性质的影响。非原位透射电子显微镜显示，无论冷却速率如何，所有样品中均存在扭曲、孪晶和倾斜畴界。此外，在不同速率下冷却的纳米管中，扭曲、孪晶和倾斜畴界的相对位置在所有以不同速率冷却的样品中保持一致。根据纳米管催化合成中基部生长和尖端生长的同时发生来解释这些结果，这表明畴界与催化颗粒耦合占据了相当稳定的位置。
