Chemists at Rice University have identified a chemical process for cutting carbon nanotubes into short segments. It yields nanotubes that are suitable for a variety of applications, including biomedical sensors small enough to migrate through cells without triggering immune reactions.

The chemical cutting process involves fluorinating the nanotubes, essentially attaching thousands of fluorine atoms to their sides, and then heating the fluoronanotubes to about 1,000 Celsius in an argon atmosphere. During the heating, the fluorine is driven off and the nanotubes are cut into segments ranging in length from 20-300 nanometers.

The highly-reactive fluorine atoms, which are attached to the walls of the nanotubes, allow scientists to create subsequent chemical reactions, attaching other substances to the nanotube walls. In this way, the group has created dozens of “designer” nanotubes, each with its own unique properties.

Rice University press release