Study on growth mechanism and controlling the structure of single walled carbon nanotubes by laser ablation technique.

用DMA(Differential Mobility Analyzer)对纳米粒子进行了粒度分类。在氦气气氛中，用脉冲激光烧蚀金属棒制备了纳米颗粒。对直径为5~15 nm的纳米粒子进行选择性分类。用场发射扫描电子显微镜和透射电子显微镜观察了纳米粒子的粒径分布。在DMA中，随着施加电压的降低，粒径分布向小直径方向移动。还研究了用这些纳米粒子进行碳纳米管的合成。考察了碳源和氢气对碳纳米管合成的影响，发现通过改变纳米粒子的直径可以控制碳纳米管的结构。

Size classification of the nano particles was performed by using DMA (Differential Mobility Analyzer). Nano particles were prepared by pulsed laser ablation of a metal rod in an atmosphere of He gas. Nano particles 5-15 nm in diameter were selectively classified. The particle diameter distributions of the nano-particles were observed by FESEM and TEM. With decreasing voltage to be applied in DMA, the particle diameter distribution shifted toward small diameter. CNTynthesis with these nano particles also studied. Effects of carbon source and hydrogen on CNTynthesis were examined and it was found that by changing the nano particle diameter it is possible to control the structure of CNT.