Advances in studying order and dynamics in condensed matter by NMR
type: CreativeWork
description: Why NMR? Because it is so informative for so many different types of applications. Since the discovery of the basic phenomenon in 1945, the field of NMR was continuously growing. NMR spectroscopy and relaxometry are powerful analytical techniques in material science and biochemistry. Magnetic resonance imaging (MRI) has a huge impact on the medical field, mentioning the non-invasive behaviour and the achievement of high spatial resolution. This work tries to emphasise three aspects for which NMR is nowadays considered unique: molecular transport, molecular dynamics, and molecular order. There is no other technique that can provide information about the translational diffusion in liquids, the type and timescale of slow molecular motion in solids as well as about the molecular order, at the same time. In this thesis, molecular transport in liquid samples is studied in terms of susceptibility induced magnetic field inhomogeneities and spectral distortions for interdiffusion in binary mixtures. Molecular order and dynamics are topics for two different soft solids, natural rubber and polyurethane. Going from extremely high homogeneity of the field required in liquid state NMR, through the microscopic world of solid state NMR, this work comes to the end with some recent ideas of more homogeneous low field devices and new magnet designs. Diffusion of liquids is an intense field of research, due to the necessity to understand the separation processes and molecular interactions. While the self-diffusion coefficients can be measured with high precision, the concentration profiles and the interdiffusion coefficients in mixtures encounter some difficulties. Therefore, the influence of the mixture heterogeneity on the magnetic field homogeneity was investigated in terms of a spatial and time-dependent magnetic susceptibility. The effect of the heterogeneous distribution of magnetic susceptibility in liquid mixtures on the static and rf field homogeneity was simulated together wi…
abstract: Why NMR? Because it is so informative for so many different types of applications. Since the discovery of the basic phenomenon in 1945, the field of NMR was continuously growing. NMR spectroscopy and relaxometry are powerful analytical techniques in material science and biochemistry. Magnetic resonance imaging (MRI) has a huge impact on the medical field, mentioning the non-invasive behaviour and the achievement of high spatial resolution. This work tries to emphasise three aspects for which NMR is nowadays considered unique: molecular transport, molecular dynamics, and molecular order. There is no other technique that can provide information about the translational diffusion in liquids, the type and timescale of slow molecular motion in solids as well as about the molecular order, at the same time. In this thesis, molecular transport in liquid samples is studied in terms of susceptibility induced magnetic field inhomogeneities and spectral distortions for interdiffusion in binary mixtures. Molecular order and dynamics are topics for two different soft solids, natural rubber and polyurethane. Going from extremely high homogeneity of the field required in liquid state NMR, through the microscopic world of solid state NMR, this work comes to the end with some recent ideas of more homogeneous low field devices and new magnet designs. Diffusion of liquids is an intense field of research, due to the necessity to understand the separation processes and molecular interactions. While the self-diffusion coefficients can be measured with high precision, the concentration profiles and the interdiffusion coefficients in mixtures encounter some difficulties. Therefore, the influence of the mixture heterogeneity on the magnetic field homogeneity was investigated in terms of a spatial and time-dependent magnetic susceptibility. The effect of the heterogeneous distribution of magnetic susceptibility in liquid mixtures on the static and rf field homogeneity was simulated together wi…
author: Voda, Mihai Adrian
language: eng
keywords: info:eu-repo/classification/ddc/530, Magnetfeld, Magnetische Suszeptibilität, Mehrquanten-NMR-Spektroskopie, Physik, Magnetfeldinhomogenitäten, Suszeptibilitätseffekte, Mehrquanten-NMR, Domänengröße, Halbach-Magnet, magnetic field inhomogeneities, magnetic susceptibility effects, multiple-quantum NMR, domain sizes, Halbach magnet
date published: 2006
date modified: 2026-07-30T19:43:10Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University