Making Carbon Nanotubes with an Underwater Arc.

The Physics Experimental Nanotechnology Group at the University of West Georgia has produced carbon nanotubes via the electric arc method. The apparatus consists of a low D.C. voltage, variable current power supply, two carbon electrodes, and a water reservoir. The arc was sustained for ten seconds, producing a carbonaceous residue on the cathode. This buildup was removed from the electrode and examined under a transmission electron microscope. Samples of nanotubes were produced in electric arcs that had direct currents ranging from 30 amps to 150 amps for a fixed voltage of 25 volts. Typical samples were 10-15 nanometers in diameter and lengths ranging up to hundreds of nanometers.