碳纳米管氧化成环制备研究

采用化学气相沉积方法制备的碳纳米管，用酸溶液进行弱氧化处理，经适当温度在大气中烧 灼后碳纳米管发生弯曲，在样品中出现大量的环状结构. 利用原子力显微镜、透射电子显微 镜和扫描电子显微镜对典型环直径为300 nm的碳纳米管环进行了表征. 烧灼温度和烧灼时间 对环的结构和产率有重要的影响. 实验数据统计结果表明，烧灼温度在510—530℃区间内 可得到超过40%的碳纳米管环产率，并且烧灼时间延长到120 min有利于提高碳纳米管环的产 率. 在加热情况下，碳纳米管端结合的羧基官能团脱水成酯，导致弯曲的碳纳米管结合成环 . 关键词： 碳纳米管环 化学气相沉积

Fabrication of carbon nanotube rings

Nanotube rings were fabricated with a high yield by heating the lightly etched c arbon nanotubes under ambient conditions that were produced by chemical vapor deposition method. These rings, typically 300nm in diameter, were characterized using atomic force microscopy, transmission electron microscopy and scanning ele ctron microscopy. The structure and yield of nanotube rings depended strongly o n the heating temperature and time. Our researches suggest that the optimal heat ing temperature ranges from 510 ℃ to 530 ℃, and that the heating time up to 1 20 min is favorable for the increase of the yield. At high temperatures, the est erification of carboxyl functional groups attached at the nanotube ends resulted in the bending of straight nanotubes into closed rings.