Sublimable Surfactant for Carbon Nanotube Dispersion: Effect of the Length of 10-n-Alkyl Side Chains of Flavin on Sublimation

Abstract We investigated the sublimation properties of 10-n-alkyl side chain flavins (n = 4–9, and 12) to address the issue of surfactant residue in single-walled carbon nanotubes (SWNTs). Thermogravimetric analysis under vacuum indicated that the 10-octyl-alkyl side chain flavin sublimated at a lower temperature than the other flavins, with a saturation vapor pressure of 0.1 Pa at 200 °C. This allowed sublimation without the competing thermal reaction. Therefore, the 10-octyl-alkyl side chain flavin is a surfactant that can separate and disperse semiconducting SWNTs for the effective utilization of their electrical properties. Moreover, it can be subsequently removed via sublimation.