Diffusion of fluids within porous materials, NMR part II

Introduction

Nuclear Magnetic Resonance (NMR) represents a notable tool to characterize molecular dynamics within both solid and liquid samples. In this project we will concentrate on relaxation time (T1 and T2) and diffusion (D) measurements of water confined within small glass beads with the object to characterize the molecular dynamics of pore-confined water. In general, NMR is capable of pinning down details regarding motional characteristics of any fluid confined in porous materials like; catalytic materials (zeolites and mesoporous materials), sandstone, clay, wood, plants and biological materials (like the human body). Also, the interaction strength between fluid molecules and surface molecules belonging to the solid matrix may be probed by this spectroscopic technique. Although a large fraction of the nuclei in the periodic table are NMR active, only the proton nuclei will be amenable for detection in this project. The outlined theory will, however, be of general validity.

Activities

Lectures and laboratory work (under supervision)

Teaching material

Distributed at the first lecture

Time schedule

Objects

• To understand the concept of relaxation and diffusion from a phenomenological point of view (Bloch equations)
• To be able to perform relaxation and diffusion measurements
• To derive information on diffusivity, surface-to-volume-ratio and surface-fluid interaction by model fitting (using PC)
• To understand the increasing complexity involved in analyzing NMR data of pore-confined fluids, as compared to bulk fluids.
• To recognize the applicability of NMR in varies aspects of material science.