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Dynamic nuclear polarization instrumentation and methodology for generating high signal sensitivity and signal contrast

Siaw, Ting Ann
Degree Grantor:
University of California, Santa Barbara. Chemical Engineering
Degree Supervisor:
Songi Han
Place of Publication:
[Santa Barbara, Calif.]
University of California, Santa Barbara
Creation Date:
Issued Date:
Chemistry, Physical and Engineering, Chemical
Solid effect DNP
Nuclear spin polarization
Dynamic Nuclear Polarization
Overhauser DNP
Alderman Grant
Cross effect DNP
Dissertations, Academic and Online resources
Ph.D.--University of California, Santa Barbara, 2013

Dynamic nuclear polarization (DNP) is an NMR method to dramatically increase NMR sensitivity and generate signal contrast by transferring the high spin polarization of electrons to nuclear spins. As an emerging NMR technique that directly addresses the inherent lack of sensitivity of NMR, the instrumentation and methodology for this technique is still in its discovery phase. This dissertation will expound on the DNP instrument and methods development to achieve the goals of generating high nuclear spin polarization, and the usage of that polarization to obtain structural information in solids and generate signal contrast for magnetic resonance imaging (MRI). The design, performance optimization and implementation of solid state DNP (ssDNP) and liquid state Overhauser DNP-MRI (ODNP-MRI) is presented.

A series of ssDNP instrument improvements culminated in the achievement of up to 61 % nuclear spin polarization in the solid state and the ability to perform versatile fundamental studies on the effect of polarizing agent, electron spin concentration, temperature and nuclear spin density on ssDNP. A case study on triblock co-polymer hydrogels was performed to demonstrate the ability of ssDNP to provide structural information in solids, revealing the capability of ssDNP detect domain separation and provide domain lengthscales from the DNP buildup measurement. To demonstrate the ability of DNP to provide signal contrast, DNP optimization was conducted in the liquid state where the ODNP mechanism is responsible for polarization transfer via the electron and nuclear spin motion. The signal enhancement and signal phase inversion generated by ODNP on water resulted in the ability to distinguish between incoming flow of ODNP-enhanced water and unenhanced bulk water during MRI.

This enabled in vitro and in vivo ODNP-MRI studies with applications in microfluidics imaging and biomedical imaging. The versatility of DNP to advance different magnetic resonance fields both in the solid and liquid state shows that the enhanced signal sensitivity and contrast produced by DNP can extend magnetic resonance techniques beyond the current state of the art.

Physical Description:
1 online resource (177 pages)
UCSB electronic theses and dissertations
Catalog System Number:
Inc.icon only.dark In Copyright
Copyright Holder:
Ting Ann Siaw
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