Linn Thrane PhD Comprehensive Exam presentation
- Wednesday, September 13, 2017 at 1:10pm
- Barnard Hall, Room 126 - view map
Nuclear Magnetic Resonance Relaxation and Diffusion Measurements to Monitor Phase Transitions
Nuclear magnetic resonance (NMR) allows for in-situ non-invasive studies of a wide range of systems at microscopic time and length scales. Multi-dimensional (NMR) relaxometry and diffusometry techniques along with magnetic resonance imaging (MRI) are applied to explore and characterize phase transitions in complex systems. High-field NMR techniques are highly sensitive to the thermodynamic phase of the system as well as restrictions on molecular motion. High resolution imaging along with T1-T2 relaxation correlation experiments and pulsed gradient stimulated echo (PGStE) NMR methods are demonstrated to characterize hydrate formation. The NMR techniques are applied to monitor the hydrate formation process in a model water-cyclopentane system at various sub cooling temperatures. Using T1-T2 correlation NMR, the transition from mobile to restricted dynamics is observed simultaneously for both water and cyclopentane throughout the hydrate formation process. Spectrally resolved diffusion measurements allow monitoring of the hydrate formation by inspecting changes in diffusion coefficients as well as changes in the ratio of water droplet sizes due to solidification of the water in the hydrate. The MR laboratory has recently obtained a low-field Rock Core Analyzer (RCA). Low-field NMR is an excellent tool for determining properties of materials with high magnetic susceptibilities and has been used to monitor changes in pore sizes and porosity due to bio mineralization in a rock core.
This proposal will discuss existing results in detail as well as how to extend the hydrate study. The proposal also describes additional projects using the RCA to 1) further investigate biofilm growth and mineralization, and 2) characterize rock core extracted from the Kevin Dome CO2 sequestration cite.
- Department of Mechanical & Industrial Engineering