title: Solid-state 13C NMR assignment of carbon resonances on metallic and semiconducting single-walled carbon nanotubes.
abstract: Solid-state (13)C NMR spectroscopy was used to investigate the chemical shift of nanotube carbons on m- and s-SWNTs (metallic and semiconducting single-walled nanotubes) for samples with widely varying s-SWNT content, including samples highly enriched with nearly 100% m- and s-SWNTs. High-resolution (13)C NMR was found to be a sensitive probe for m- and s-SWNTs in mixed SWNT samples with diameters of approximately 1.3 nm. The two highly enriched m- and s-SWNT samples clearly exhibited features for m- and s-SNWT (13)C nuclei (approximately 123 and 122 ppm, respectively) and were successfully fit with a single Gaussian, while five mixed samples required two Gaussians for a satisfactory fit.
authors.affiliation: National Renewable Energy Laboratory, Golden, Colorado 80401, USA. Chaiwat.Engtrakul@nrel.gov
authors.forename: Chaiwat
authors.initials: C
authors.lastname: Engtrakul
authors.forename: Mark F
authors.initials: MF
authors.lastname: Davis
authors.forename: Kevin
authors.initials: K
authors.lastname: Mistry
authors.forename: Brian A
authors.initials: BA
authors.lastname: Larsen
authors.forename: Anne C
authors.initials: AC
authors.lastname: Dillon
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Heben
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Blackburn