Fabrication of Carbon Nanotubes and Byproducts by Arc Discharge in DC Motors

The electrical arc generated between the brush and commutator of a DC motor is similar to the arc discharged between carbon electrodes. Since carbon nanotubes are produced by carbon electrode are discharge, it is possible to produce carbon nanotubes and byproducts via the electrical arc generated between the brush and commutator of a DC motor. In this paper, we demonstrate experimentally that single-wall carbon nanotubes and byproducts were generated on the surface of the brushes by the electrical arc of DC motors. The yield of the nanotubes was very low, and the nanotubes were of poor structural quality. If carbon nanotubes with a high electrical conductivity are produced across the segmented copper bars of the commutator, they can potentially cause the DC motor to flashover. Our experimental findings reveal that these carbon nanotubes and byproducts have no effect on the flashover of DC motors because they are extremely small and occur in small quantities. (C) 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.