title: Ballistic and non-ballistic gas flow through ultrathin nanopores.
abstract: We show that ultrathin porous nanocrystalline silicon membranes exhibit gas permeance that is several orders of magnitude higher than other membranes. Using these membranes, gas flow obeying Knudsen diffusion has been studied in pores with lengths and diameters in the tens of nanometers regime. The components of the flow due to ballistic transport and transport after reflection from the pore walls were separated and quantified as a function of pore diameter. These results were obtained in pores made in silicon. We demonstrate that changing the pore interior to carbon leads to flow enhancement resulting from a change in the nature of molecule-pore wall interactions. This result confirms previously published flow enhancement results obtained in carbon nanotubes.
authors.affiliation: Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY 14627, USA.
authors.forename: M N
authors.initials: MN
authors.lastname: Kavalenka
authors.forename: C C
authors.initials: CC
authors.lastname: Striemer
authors.forename: D Z
authors.initials: DZ
authors.lastname: Fang
authors.forename: T R
authors.initials: TR
authors.lastname: Gaborski
authors.forename: J L
authors.initials: JL
authors.lastname: McGrath
authors.forename: P M
authors.initials: PM
authors.lastname: Fauchet
mesh_terms: D002244:Carbon / Q000737:chemistry*; D004058:Diffusion; D005740:Gases / Q000737:chemistry*; D008567:Membranes, Artificial; D046529:Microscopy, Electron, Transmission; D058608:Nanopores / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D016062:Porosity; D012825:Silicon / Q000737:chemistry*
chemical_list: D005740:Gases; D008567:Membranes, Artificial; D002244:Carbon; D012825:Silicon