title: Carbon Nanotubes Immersed in Superfluid Helium: The Impact of Quantum Confinement on Wetting and Capillary Action.
abstract: A recent experimental study [ Ohba, Sci. Rep. 2016, 6, 28992 ] of gas adsorption on single-walled carbon nanotubes at temperatures between 2 and 5 K reported a quenched propagation of helium through carbon nanotubes with diameters below 7 Å despite the small kinetic diameter of helium atoms. After assessing the performance of a potential model for the He-nanotube interaction via ab initio calculations with density functional theory-based symmetry adapted perturbation theory, we apply orbital-free helium density functional theory to show that the counterintuitive experimental result is a consequence of the exceptionally high zero-point energy of helium and its tendency to form spatially separated layers of helium upon adsorption at the lowest temperatures. Helium filling factors are derived for a series of carbon nanotubes and compared to the available experimental data.
authors.affiliation: Institute of Experimental Physics, Graz University of Technology , Petersgasse 16, 8010 Graz, Austria.
authors.forename: Andreas W
authors.initials: AW
authors.lastname: Hauser
authors.affiliation: Instituto de Física Fundamental, CSIC , Serrano 123, 28006 Madrid, Spain.
authors.forename: María Pilar
authors.initials: MP
authors.lastname: de Lara-Castells