Single-Handed Helical Carbonaceous Nanotubes: Preparation, Optical Activity, and Applications.

Carbon-based nanomaterials have been widely studied in the past decade. Three approaches have been developed for the preparation of single-handed helical carbonaceous nanotubes. The first approach uses the carbonization of organopolymeric nanotubes, where the organic polymers are polypyrrole, 3-aminophenol-formaldehyde resin, and m-diaminobenzene-formaldehyde resin. The second approach uses the carbonization of aromatic ring-bridged polybissilsesquioxane followed by the removal of silica. Micropores exist within the walls of the carbonaceous nanotubes. The third approach uses the carbonization of organic compounds within silica nanotubes. This hard-templating approach drives the formation of helical carbonaceous nanotubes containing twisted carbonaceous nanoribbons. All of these helical carbonaceous nanotubes exhibit optical activity, which is believed to originate from the chiral π-π stacking of aromatic rings. They can be used as chirality inducers, and for lithium-ion storage.