title: Size selectivity of narrow pores.
abstract: The selectivity of micropores and ion channels is examined for simple pore topologies within the framework of density functional theory of highly confined fluids. In an infinite cylindrical pore purely steric (excluded volume) effects are shown to lead to strong, nontrivial size selectivity, which is highly sensitive to the pore radius. A crude modeling of electrostatic effects does not alter the relative absorbance of Na+ and K+ ions in a significant way.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 3QZ United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Goulding
authors.forename: J P
authors.initials: JP
authors.lastname: Hansen
authors.forename: S
authors.initials: S
authors.lastname: Melchionna
mesh_terms: D007473:Ion Channels / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D055672:Static Electricity; D013379:Substrate Specificity; D014867:Water / Q000378:metabolism
chemical_list: D007473:Ion Channels; D014867:Water; D012964:Sodium; D011188:Potassium