Single wall CNTs are nanomaterials. When the scale of a material is reduced to the nanometer scale, it will produce especially excellent properties and effect, including self-assembly effect, small size effect, surface effect and quantum effect. The single wall CNT is consisted of only one cylindrical surface that made of carbon atoms. The walls of the single wall CNT are made up of hexagonal grids that similar to graphite sheets. Carbon atoms are located in the intersection of hexagonal grids and every carbon atom is adjacent to other three surrounding carbon atoms. The diameter of single wall CNT can be determined by Raman spectroscopy, most of which are between 1.16 nm and 1.60 nm. In the single wall CNT, the motion of electrons in the radial direction is limited, but the motion of electrons along the axial direction is not limited. Therefore, single wall CNT can be considered as a one-dimensional quantum wire. In addition, because of the surface effect, single wall CNT generally has a large specific surface area.
Figure 1. The structure of single wall CNT.
Figure 2. The ink based on single walled carbon nanotube for supercapacitors.
According to the solubility, single wall CNTs can be divided into water-soluble single wall CNTs and water-insoluble single wall CNTs.