title: Microimaging of transient guest profiles to monitor mass transfer in nanoporous materials.
abstract: The intense interactions of guest molecules with the pore walls of nanoporous materials is the subject of continued fundamental research. Stimulated by their thermal energy, the guest molecules in these materials are subject to a continuous, irregular motion, referred to as diffusion. Diffusion, which is omnipresent in nature, influences the efficacy of nanoporous materials in reaction and separation processes. The recently introduced techniques of microimaging by interference and infrared microscopy provide us with a wealth of information on diffusion, hitherto inaccessible from commonly used techniques. Examples include the determination of surface barriers and the sticking coefficient's analogue, namely the probability that, on colliding with the particle surface, a molecule may continue its diffusion path into the interior. Microimaging is further seen to open new vistas in multicomponent guest diffusion (including the detection of a reversal in the preferred diffusion pathways), in guest-induced phase transitions in nanoporous materials and in matching the results of diffusion studies under equilibrium and non-equilibrium conditions.
authors.affiliation: Department of Interface Physics, University of Leipzig, Linnestrasse 5, 04103 Leipzig, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Kärger
authors.affiliation: Department of Interface Physics, University of Leipzig, Linnestrasse 5, 04103 Leipzig, Germany.
authors.forename: Tomas
authors.initials: T
authors.lastname: Binder
authors.affiliation: Department of Interface Physics, University of Leipzig, Linnestrasse 5, 04103 Leipzig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Chmelik
authors.affiliation: Department of Interface Physics, University of Leipzig, Linnestrasse 5, 04103 Leipzig, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Hibbe
authors.affiliation: Institute of Inorganic Chemistry, University of Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Krautscheid
authors.affiliation: Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Rajamani
authors.initials: R
authors.lastname: Krishna
authors.affiliation: Institute of Chemical Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Weitkamp