Diffusion processes in unsaturated porous media studied with nuclear magnetic resonance techniques [Elektronische Ressource] / vorgelegt von Germán David Farrher

Universität Ulm Sektion Kernresonanzspektroskopie _________________________________________________________________________________________________________ Diffusion processes in unsaturated porous media studied with Nuclear Magnetic Resonance techniques DISSERTATION zur Erlangung des Doktorgrades Dr. rer. nat. Der Fakultät Naturwissenschaften Der Universität Ulm vorgelegt von Germán David Farrher aus Maggiolo, Argentinien Ulm, 2006 Amtierender Dekan: Prof. Dr. Klaus-Dieter Spindler Erstgutachter: Prof. Dr. Rainer Kimmich Zweitgutachter: Prof. Dr. Hartmut Jex Tag der Promotion: 31.01.2007 Dedicated to my parents, my grandparents, my brothers, and to the loves of life, Tali, Damian and Noa. Diffusion processes in unsaturated porous media studied with Nuclear Magnetic Resonance techniques Abstract Unsaturated porous media form two-phase systems consisting of the liquid and its vapor. Molecular exchange between the two phases defines an effective diffusion coefficient which substantially deviates from the bulk value of the liquid. The objective of the present thesis is to study self-diffusion under such conditions by varying both the filling degree of the porous medium and the diffusion time. The main experimental tool was a combination of two different NMR field gradient diffusometry techniques.