High pressure and high temperature induced polymerization of C60 nanotubes

C-60 nanotubes with outer diameters ranging from 400-800 nm were polymerized at 1.5 GPa, 573 K and 2.0 GPa, 700 K, respectively. Raman and photoluminescence spectroscopy were employed to characterize the polymeric phases of the treated samples. Both Raman and photoluminescence spectra showed that the C-60 nanotubes transformed into the dimer and orthorhombic phases under the two different conditions, respectively. The photoluminescence peaks were tuned from visible to near infrared range. Comparative studies indicated that C-60 nanotubes were more difficult to polymerize than bulk C-60 material under the same conditions due to the nanoscale size effect in the C-60 nanotubes.