Regensburg 2010 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 59: Phase Transitions I

MM 59.4: Vortrag

Donnerstag, 25. März 2010, 14:45–15:00, H5

Memory Effects in Confined Fluids via Diffusion Measurement — •Sergej Naumov, Rustem Valiullin, and Jörg Kärger — Universität Leipzig, Fak. Phys, u. Geowiss., Linnestr. 5, 04105, Deutschland

The detailed knowledge about the molecular transport in nanoporous materials is of enormous importance for the industrial applications. The transport of molecules in the nanopores can be affected by gas-liquid phase transitions. The latter are often accompanied by adsorption hysteresis, i.e., the concentration of the molecules inside the pores depends not only on the external parameters like gas pressure or temperature, but also on the history how the external parameters have been varied. The evolution of the fluid state may be probed by means of Pulsed Field Gradient NMR which can trace the amount adsorbed simultaneously with the self-diffusion coefficients of the molecules [1]. The thus obtained self-diffusivities are found to depend not only on fluid concentration, but also on the history how a particular concentration has been attained [2].

[1] Naumov, S.; Valiullin, R.; Monson, P. A.; Kärger, J., Langmuir, 2008, 24, 6429-6432

[2] Valiullin, R.; Naumov, S.; Galvosas, P.; Kärger, J.; Woo, H.; Porcheron, F.; Monson, P. A. Nature, 2006, 443, 965-968