Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"Diffusometry"”.
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NMR Relaxometry and Diffusometry Studies for Investigating Heterogeneous Catalysis
The work described in this thesis mainly concerns the development and implementation of nuclear magnetic resonance (NMR) methods to provide quantitative information on chemical conversion within a novel NMR compatible trickle-bed reactor (TBR). Techniques to map the distribution of chemical species …
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Probing Morphology, Transport and Local Intermolecular Interactions in Polymeric Materials via NMR Diffusometry and Spectroscopy
Understanding transport of water molecules and salt ions from a molecular level up to macroscopic length scales is critical to the design of novel materials for many applications, including separations membranes for fuel cell and desalination applications, as well as rechargeable battery …
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Development and Application of NMR Diffusometry and Relaxometry Methodologies to Study Organic-Inorganic Interactions at Nanomaterial Surfaces
<p>Colloidal nanomaterials like semiconductor quantum dots (QDs) have size-, shape-, and composition-dependent optoelectronic properties with applications ranging from photovoltaics, to sensing, to medical diagnostics and treatment. These materials also have very high surfaceto- volume ratios, with …
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Probing diffusion and molecular dynamics to study self-assembly and intermolecular interactions in macromolecular and colloidal systems using NMR diffusometry and spectroscopy
… colloidal systems. Two key NMR techniques – NMR diffusometry and dynamic NMR spectroscopy – are employed to probe the motion and exchange process of molecules within these systems. By providing insights into the dynamics of the constituents, these methods are particularly powerful in unraveling …
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Block Copolymer Solutions: Transport and Dynamics, Targeted Cargo Delivery, and Molecular Partitioning and Exchange
… including NMR spectroscopy, relaxometry and diffusometry, can provide valuable molecular information, such as chemical structure, translational motion, inter- or intramolecular interaction, dynamics, and exchange kinetics. Therefore, this dissertation describes applications of versatile NMR …
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Probing Transport of Ion Dense Electrolytes using Electrophoretic NMR
… electrolytes using electrophoretic NMR and NMR diffusometry. I first describe the design and fabrication of the first instrumentation capable of reliable ENMR on highly ion-dense electrolytes such as ionic liquids and electrolytes for zinc-air batteries. I design a new electrophoretic NMR sample …
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Nuclear Magnetic Resonance Studies of Imidazolium-Based Ionic Liquids and Garnet-Type Li7La3Zr2O12
… to probe particle dynamics (magnetic relaxation, diffusometry, etc.) and material structures (spectroscopy) down to the atomic level. In this work, several NMR techniques are employed to study imidazolium-based ionic liquids and garnet-type inorganic materials. These are being studied due to their …
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Multiscale Tortuous Diffusion in Anion- and Cation-Exchange Membranes: Exploration of Counterions, Water Content, and Polymer Functionality
… and CEMs using pulsed-field-gradient (PFG) NMR diffusometry. Water diffusion in both AEMs and CEMs exhibit specific trends as a function of water uptake (wt%), indicating morphological similarities across common chemical structures. Furthermore, restricted diffusion reveals micron-scale …
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Multiscale Transport and Dynamics in Ion-Dense Organic Electrolytes and Copolymer Micelles
… temperature pulsed-field-gradient (PFG) NMR diffusometry, which can probe molecular transport over nm – μm length scales, I first explore transport and morphology on a series of ion-conducting materials: an organic ionic plastic crystal, a proton-exchange membrane, and a polymer-gel …
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Transport and Anisotropy inside Ionic Polymer Membranes
… slow diffusing high γ nuclei. Then I employ NMR diffusometry to investigate transport and anisotropy for a series of ionic polymers, from poly(arylene ether sulfone) hydrophilic-hydrophobic multi-block copolymers to polymer blends to perfluorosulfonate random copolymers. For the multi-block …
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NMR Techniques for Measuring Transport Phenomena in Microporous Materials
… species using NMR spectroscopy, relaxometry and diffusometry without the use of Magic Angle Spinning (MAS). This connoted that conventional PFG NMR is capable of precisely characterising individual species in real world multi-component systems. This thesis also describes the self-diffusion of …
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Bridging Mesoscale Phenomena and Macroscopic Properties in Block Copolymers Containing Ionic Interactions and Hydrogen Bonding
… investigated thoroughly using in situ FTIR, NMR diffusometry, and simulation. Monomer diffusion and aggregation barely contributed to the kinetic differences, and the Marcus theory was applied to explain the polymerization kinetic differences which showed promising simulation results. RAFT …
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NMR Applications in Soft Materials Science: Correlation of Structure, Dynamics, and Transport
… including solid-state NMR (SSNMR), diffusometry, and imaging, and with the help of X-ray scattering. First, we report the investigation of structure and dynamics of three polymeric membranes: hydroxyalkyl-containing imidazolium homopolymers, poly(arylene ether sulfone) segmented …
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Nanoscale Liquid Dynamics in Membrane Matrices: Insights into Confinement, Molecular Interactions, and Hydration
This dissertation focuses on the fundamental understanding of liquid dynamics confined in polymer membranes. Such knowledge guides the development of better polymer membranes for practical applications and contributes to the general understanding of confined liquid dynamics in various nanoporous …