Researchers Put a New Twist on Carbon Nanotubes
Working independently, two Japanese university research teams have developed similar methods for synthesizing carbon nanotubes with a coiled shape. First discovered in 1991 by Sumio Iijima, carbon nanotubes are fullerene-related graphite cylinders closed at both ends with pentagonal caps. These structures are normally produced using arc evaporation or laser vaporization of carbon molecules, resulting in straight tubes with one or more walls. Scientists at the Toyohashi University of Technology and the Osaka Prefecture University, however, have formulated a means of reacting a hot organic gas with a catalytic substrate that results in coiled nanotubes.
Carbon nanocoils have a broad range of electrical, thermal, and structural properties that may make them useful for a variety of applications. Among other functions, they could be used to keep small blood vessels open, emit electrons in flat-panel displays, and act as springs in micromachines. Because they can be opened and filled, the coils may also be used to absorb gasses and to block electromagnetic radiation. Both university groups plan to continue their research to discover ways of freely controlling the size of the coils.