Scientists at the Thomas Jefferson National Accelerator Facility, Newport News, Va., have developed a new technique for turning boron into highly crystalline boron-nitride nanotubes with small diameters that can be spun into usable yarns.
The new production method, called the pressurized vapor/condenser method, was developed with Jefferson Lab’s free-electron laser and later perfected using a commercial welding laser. The laser is fired at a sample of boron in a chamber filled with pressurized nitrogen. The boron vaporizes into a plume. A cooled metal wire inserted in the plume acts as a condenser to precipitate boron droplets. These droplets combine with nitrogen and self-assemble into boron-nitride nanotubes. The tubes, each about 1-mm long, can be handled by commercial textile manufacturing and handling techniques once spun into yarn.
Researchers are still determining the properties of the new nanotubes and investigating methods of scaling up production. They plan on blending the yarns into items such as body armor and solar cells.