Carbon Nanotubes - Introduction

Multi-wall carbon nanotubes (MWCNTs) can be regarded as a coaxial assembly of single wall carbon nanotubes (see image on left). The separation between neighbouring tubes is close to the separation between graphite layers. Typical diameters of MWCNTs are in the range of 5 - 50 nm.

A single wall carbon nanotube (SWCNT) can be thought of as a sheet of graphite (a hexagonal lattice of carbon) rolled into a cylinder. Typical diameters of SWCNTs are in the range of 0.7 - 1.4 nm and their length can be of several micrometers.

The image shows the different types of carbon structures: diamond, fullerene, graphite, and nanotube structure.