Question

Structure of carbon nanotubes structure dependinv on n and m

Answer 1

Buckytubes are single-wall carbon nanotubes, in which a single layer of graphite - graphene - is rolled up into a seamless tube. Graphene consists of a hexagonal structure like chicken wire. If you imagine rolling up graphene or chicken wire into a seamless tube, this can be accomplished in various ways. For example, carbon-carbon bonds (the wires in chicken wire) can be parallel or perpendicular to the tube axis, resulting in a tube where the hexagons circle the tube like a belt, but are oriented differently. Alternatively, the carbon-carbon bonds need not be either parallel or perpendicular, in which case the hexagons will spiral around the tube with a pitch depending on how the tube is wrapped. Figure 1 illustrates these points: