title: Evidence of water adsorption in hydrophobic nanospaces of highly pure double-walled carbon nanotubes.
abstract: Highly pure double-walled carbon nanotubes synthesized by a catalytic chemical vapor deposition method have a quasi one-dimensional nanopore system. We determined these nanotubes' nanopore structures by means of molecular probe adsorption using N(2) at 77 K, CO(2) at 273 K, and water at 298, 308, and 318 K, as well as high-resolution transmission electron microscopy. The water vapor adsorption behavior of this system was quite unusual. At a lower relative pressure of P/P(0) = 0.3-0.65, water filled the interstitial nanopores, and at relative pressures higher than this range, water also filled the interbundle nanopores. This study is the first to our knowledge that has provided direct evidence of water adsorption in hydrophobic nanospaces of highly pure double-walled carbon nanotubes.
authors.affiliation: Institute of Carbon Science and Technology, Shinshu University, Nagano 380-8553, Japan. tao@endomoribu.shinshu-u.ac.jp
authors.forename: Yousheng
authors.initials: Y
authors.lastname: Tao
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Muramatsu
authors.forename: Morinobu
authors.initials: M
authors.lastname: Endo
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D000327:Adsorption; D057927:Hydrophobic and Hydrophilic Interactions; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D014867:Water / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D014867:Water