Carbon nanotubes have stimulated a massive amount of research and interest since their discovery, particularly because of their excellent thermal conductivity and mechanical and electrical properties. These properties do depend on the structure of the nanotube, however, and so they must be thoroughly analysed in order for their applications to be investigated.
Anyone who has worked in this field at any point will know that the usual methods of analysis involve electron microscopy techniques, such as Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques. These are very expensive, time-consuming and require training for their operation.
This paper, in the Journal of the American Chemical Society, describes work by a research group in the United States, describes a new technique which makes carbon nanotubes visible under regular optical microscopes. The team have utilised the ability of carbon nanotubes to enhance the vapour phase etching of silica surfaces by HF – allowing trenches to be formed which show precisely where the nanotubes are located.
This new method doesn’t use any labels or markers, meaning that the nanotubes aren’t contaminated or altered in any way. As a proof of concept, Raman spectroscopy was carried out on the nanotubes in order to characterise them and monitor an oxidation reaction with Ozone.
Although this report is quite a preliminary study, the ability to study and monitor carbon nanotubes using such a cheap and quick method could have massive impact on this area, and pave the way for a real boost in this research.