Abstract
The structural change of C60 nanotubes (C60NTs) by heating in vacuum was investigated using thermo-gravimetric analysis (TGA), transmission electron microscopy (TEM) and Raman spectroscopy. The C60NTs were prepared by use of a pyridine solution saturated with C60 and isopropyl alcohol (IPA). A weight loss of about 4 % in the C60NTs dried at room temperature was observed by heating up to 400°C in a N2 atmosphere, and the C60NTs started to decompose from about 600°C. The Ag(2) peak of as-prepared C60NTs shows a Raman shift indicating one-dimensionally polymerized C60, while the C60NTs heated at 100°C ∼ 500°C in vacuum show Ag(2) peaks characteristic of van der Waals C60 crystals, suggesting a change of bonding state of C60 molecules by heat treatment. TEM observations show that the crystallinity and surface morphology of C60NTs are degraded by high-temperature heat treatment in vacuum.
