The Korea Institute of Science and Technology (KIST) announced on June 9 that a research team led by Dr. Lee Jae-gap from the Interface Control Research Center at KIST found some single-walled carbon nanotubes (CNTs) that are not a single layer graphene cylinder, but a graphene helix.
CNTs are the strongest, lightest and most conductive material known: they are 100 times as strong as steel, and their electrical conductivity and heat conductivity is similar to that of copper and diamond. Therefore, they are hailed as a next-gen dream material that can be utilized in various industries such as semiconductors, airplanes, and cars.
When the material was first discovered by Japanese researcher Sumio Iijima in 1991, CNTs were believed to have a cylindrical structure in which hexagons composed of six carbon atoms are interconnected.
However, the research team found some CNTs that do not have a cylindrical structure but a helix, after conducting a detailed analysis using an electron microscope with a high resolving power and an atomic force microscope. A nodal structure formed by helical cracks is evidence for this theory. The team also said that this may be true for all CNTs.
If all CNTs have this helical structure rather than a cylindrical one, it means that contrary to expectations, CNTs may not work as semiconductors, because a cylindrical structure would be required for that. Dr. Lee remarked, “The outcome of our study is likely to create a stir in the academic circles of physics and nano-materials, since it will be necessary to modify numerous research findings that have been done over the past 20 years.”