Low degree of functionalization of Single-Walled Carbon Nanotubes probed by highly sensitive characterization techniques

Single-Walled Carbon Nanotubes (SWCNTs) were functionalized using a one-step radical addition procedure leading to a desired low functionalization degree. Based on well chosen techniques, the characterization of the functionalized samples allows having a good feedback on the functionalization process. We were able to determine the functionalization level and the nature of the bonds between the SWCNT surface and the functional groups. By means of a TGA-mass spectrometry coupling technique, the mechanisms of detachment upon heating were used to determine the nature of the grafted functional groups. In addition to the expected groups, unexpected groups were covalently grafted on the sample surface. Based on inert gas adsorption properties, we show that the functional groups are unambiguously grafted on the SWCNT sidewalls. (C) 2011 Elsevier Ltd. All rights reserved.