Carbon nanotubes, like their cousin graphene, have the potential to greatly enhance modern technology thanks to their small size, incredible strength, and good conduction. For mass production and use though there has to be some way to identify the highest quality samples and filter out those with imperfections. Researchers at Rice University appear to have found a characteristic of impurities which may aid in this way.
After painstakingly analyzing individual nanotubes, the researchers are confident in their conclusion that the fluorescence of nanotubes is directly linked to both their length and purity. The brightness seems to be limited by the length of the nanotubes, with longer samples shining brightest, but when length was held constant the brightness still varied. When a nanotube is damaged or defective, there can be other atoms attached to its surface which can disrupt the emission of light.
Fortunately the researchers have worked out an automated way to continue this research, shortening the time needed from months to just weeks. With this tool the researchers want to determine if specific production methods are causing damage to the nanotubes as they are grown.