title: Foam films as thin liquid gas separation membranes.
abstract: In this letter, we testify the feasibility of using freestanding foam films as a thin liquid gas separation membrane. Diminishing bubble method was used as a tool to measure the permeability of pure gases like argon, nitrogen, and oxygen in addition to atmospheric air. All components of the foam film including the nature of the tail (fluorocarbon vs hydrocarbon), charge on the headgroup (anionic, cationic, and nonionic) and the thickness of the water core (Newton black film vs Common black film) were systematically varied to understand the permeation phenomena of pure gases. Overall results indicate that the permeability values for different gases are in accordance with magnitude of their molecular diameter. A smaller gaseous molecule permeates faster than the larger ones, indicating a new realm of application for foam films as size selective separation membranes.
authors.affiliation: Max-Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany. nmr@ornl.gov
authors.forename: Muruganathan
authors.initials: M
authors.lastname: Ramanathan
authors.forename: Hans Joachim
authors.initials: HJ
authors.lastname: Müller
authors.forename: Helmuth
authors.initials: H
authors.lastname: Möhwald
authors.forename: Rumen
authors.initials: R
authors.lastname: Krastev
mesh_terms: D005240:Feasibility Studies; D005740:Gases / Q000737:chemistry* / Q000302:isolation & purification*; D008422:Materials Testing; D008567:Membranes, Artificial; D010539:Permeability; D016062:Porosity; D012996:Solutions / Q000302:isolation & purification*; D014462:Ultrafiltration / Q000379:methods*
chemical_list: D005740:Gases; D008567:Membranes, Artificial; D012996:Solutions