Adsorption onto and into single-walled carbon nanotubes: Probing the world's smallest test tubes

PRES 66

John T. Yates Jr., jyates@pitt.edu, Department of Chemistry, University of Pittsburgh, 234 Chevron Science Center, 219 Parkman Avenue, Pittsburgh, PA 15260
Rick Smalley first recognized that SWNTs would likely be excellent adsorbents as a result of the enhanced attractive forces expected for molecules located inside the nanotubes. He convinced me to undertake a study of adsorption on nanotubes, and 6 years of exciting work has evolved as a result of his brief phone call. We have used infrared spectroscopy, NEXAFS, and thermal desorption methods, finding: (1) Adsorption in the interior sites is facilitated by the thermal removal of oxidized functionalities such as -COOH and –C-O-C-groups, opening entry ports for adsorption into the SWNTs; (2) Internally bound molecules exhibit significant redshifts in their vibrational modes; (3) Confined H2O molecules form (H2O)x clusters with different hydrogen bonds within the clusters compared to the hydrogen bonding between the clusters; (4) Long chain alkanes adsorb in a linear fashion within the groove sites formed between SWNTs bound together in bundles. A brief description of the highlights from each of these four areas will be presented.