title: A molecular simulation study of propane and propylene adsorption onto single-walled carbon nanotube bundles.
abstract: We have carried out configurational-bias Grand Canonical Monte Carlo simulations of propane and propylene adsorption onto homogeneous bundles of single-walled carbon nanotubes, at ambient temperature (T = 298.15 K) and over a pressure range of 0.1 bar < or = p < 10.4 bar. The distinct contributions from external sites (grooves and external surface) and endohedral volume (inter- and intra-tubular) are individually addressed for bundles with nanotube diameters (D) within the range 11.0 A < D < or = 18.1 A. The different contributions from the various adsorption sites are interpreted from a molecular perspective, which takes into account both the skeletal geometry of the bundle and individual tube diameter. The resulting microscopic picture is then related to a macroscopic measurable isotherm by modeling the nanotube bundles, as a function of a characteristic hydraulic diameter (Dh) over the range 100 A < or = Dh < or = 310 A. A previously unobserved anisotropic behavior of the adsorption isotherm for the peripheral surface of the bundles as a function of hydraulic diameter is reported.
authors.affiliation: Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
authors.forename: Fernando J A L
authors.initials: FJ
authors.lastname: Cruz
authors.forename: Isabel A A C
authors.initials: IA
authors.lastname: Esteves
authors.forename: José P B
authors.initials: JP
authors.lastname: Mota
authors.forename: Sandeep
authors.initials: S
authors.lastname: Agnihotri
authors.forename: Erich A
authors.initials: EA
authors.lastname: Müller