This thesis summarizes experimental results on mass transport of small hydrocarbons in micro-porous crystals obtained via interference microscopy (IFM). The transport process has been investigated in three difffferent materials with difffferent pore structures : the metal-organic framework Zn(tbip) with one-dimensional pores, a FER type zeolite with two-dimensional anisotropic pore structure and zeolite A, a LTA type material with isotropic three-dimensional pore structure.
Mass transport is described in terms of diffffusivity and surface permeability, both derived from the detected transient concentration profiles. The results on intra-crystalline diffffusion are discussed under consideration of the influences of pore diameter and molecule diameter, which are both found to have a strong influence on the diffffusivity.
Based on experimental results measured on the Zn(tbip) material, a new model for the description of surface barriers is developed and proved by experiment. It is demonstrated that the observed surface barrier is created by the total blockage of a large number of pore entrances at the surface and not by a homogeneous surface layer.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:11826 |
| Date | 05 December 2012 |
| Creators | Hibbe, Florian |
| Contributors | Kärger, Jörg, Smarsly, Bernd, Universität Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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