A simple method was proposed for locating defect sites in individual single-walled carbon nanotubes using an atomic force microscopic technique and a thermal oxidation strategy. After thermal oxidation of well-dispersed single-walled carbon nanotubes on a silicon surface in air at 500C, almost all of the original single-walled carbon nanotubes were fractured into short fragments. The range of the fragment sizes was different and was closely related to the length and growth-time of the tubes. The rupture of single-walled carbon nanotubes was confirmed to be a result of the presence of defects in tubes and to be caused by the attack of oxygen molecules in air. Owing to the damage events that occurred in single-walled carbon nanotubes after heat treatment, a thermal oxidation method could be a potentially useful technique for the cutting of single-walled carbon nanotubes. Chemical functionality of the single-walled carbon nanotubes could also be achieved during this process. A thermal treatment method could be employed as another useful cutting and functionalizing approach for tailoring the chemical and physical properties of single-walled carbon nanotubes.

Defect Location of Individual Single-Walled Carbon Nanotubes with a Thermal Oxidation Strategy. Q.Li, H.Yan, Y.Ye, J.Zhang, Z.Liu: Journal of Physical Chemistry B, 2002, 106[43], 11085-8