Single-Walled NanotubeThe state-of-the-art in bulk fabrication of single walled carbon nanotubes (SWCNT) yields bundles comprising tubes in a wide range of diameters (0.7-1.1 nm in laser induced methods, 0.8-1.6nm in arc methods). Properties of SWCNTs strongly depend on their diameter and chirality, especially when dispersed. For example, bundled SWCNTs do not show fluorescence; however, dispersed nanotubes fluoresce at a wavelength that depends on the diameter and chirality of the nanotube. Therefore, a typical sample will show a wide range of response depending on how many different types of nanotubes it contains. Our ongoing research aims to establish a fabrication procedure able to yield SWNTs with a distribution of diameters of ±0.05 nm. We conduct experimental and theoretical research to measure and analyze the change in the thermodynamic conditions during the growth of SWCNTs using the arc technique, to determine the relevance of the process parameters and their influence in the diameter of the SWCNTs.