Determination of Carbon Nanotube Modification by TG-MS and Pyrolysis-GC/MS

摘要

Uniform dispersion of carbon nanotubes (CNTs) has been one of the major impediments to the full development of the incredible suite of properties offered by CNTs, specifically single-walled carbon nanotubes (SWNTs). However, investigators at NASA Langley and the National Institute of Aerospace Research have recently obtained (SWNTs) that are soluble in select solvents, including THF, DM Ac, and ODCB. The SWNTs were exposed to reagents used in cited fullerene modification chemistry in an attempt to produce soluble SWNTs. Upon further examination, it was determined that the intended functionalization had not occurred, and some other phenomenon was responsible for the SWNTs solubility. Determination of what was imparting solubility to the SWNTs was the goal of this project. The two evolved gas analysis (EGA) techniques used during this project were thermogravi me try-mass spectrometry (TG-MS) and pyrolysis-gas chromatography/mass spectrometry (GC/MS). Samples were heated while the gasses evolved were monitored to determine their identities. The soluble SWNTs were less stable than the non-soluble SWNTS. In addition, they also had much more complicated degradation schemes as evidenced by the additional mass loss events seen in the TG-MS data. Based on the data, some form of methoxide or methanol is imparting solubility to the SWNTs.