Diffusion is an omnipresent, most fundamental phenomenon in nature and thus critical for
the performance of numerous technologies. This is in particular true for nanoporous materials
with manifold applications for matter upgrading by separation, purification and conversion. The
path lengths of molecular transportation within the industrial plants range from the elementary
steps of diffusion within the micropores of the individual particles up to the matter flow over
macroscopic distances. Each of them might be decisive in determining overall performance so
that detailed knowledge of all modes of mass transfer is crucial for a knowledge-based
optimization of the devices with reference to their transport properties. The rate of mass transfer
is particularly complicated to be assessed within the individual (adsorbent) particles/crystallites
with pore sizes of the order of molecular dimensions. We are going to present two powerful
techniques exactly for this application, operating under both equilibrium (Pulsed Field Gradient
(PFG) NMR) and non-equilibrium (Microimaging by interference microscopy and IR
microscopy) conditions. The potentials of these techniques are demonstrated in a few
showcases, notably including the options of transport enhancement in pore hierarchies. The
contribution concludes with a survey on present activities within an IUPAC initiative aiming at
the elaboration of “guidelines for measurements and reporting of diffusion properties of
chemical compounds in nanoporous materials”.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:80748 |
| Date | 22 September 2022 |
| Creators | Chmelik, Christian, Hwang, Seungtaik, Kärger, Jörg |
| Publisher | University of Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1862-4138, urn:nbn:de:bsz:15-qucosa2-806868, 06, qucosa:80686 |
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