Solid state NMR studies of materials for energy technology
Item
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Title
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Solid state NMR studies of materials for energy technology
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Identifier
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d_2009_2013:bffff86e5f05:10428
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identifier
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10511
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Creator
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Nambukara Kodiweera Arachchilage, Chandana K.,
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Contributor
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Steve Greenbaum
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Date
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2010
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Language
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English
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Publisher
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City University of New York.
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Subject
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Solid state physics | Condensed matter physics | Molecular physics | Alternative Energy | Direct methanol Fuel cell and PFG spin echo | NMR and PEM Fuel Cells | NMR Studies | Nuclear Magnetic Resonance | Pulse field gradient | Solid state NMR
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Abstract
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Presented in this dissertation are NMR investigations of the dynamical and structural properties of materials for energy conversion and storage devices. 1H and 2H NMR was used to study water and methanol transportation in sulfonated poly(arylene ether ketone) based membranes for direct methanol fuel cells (DMFC). These results are presented in chapter 3. The amount of liquid in the membrane and ion exchange capacity (IEC) are two main factors that govern the dynamics in these membranes. Water and methanol diffusion coefficients also are comparable. Chapters 4 and 5 are concerned with 31P and 1H NMR in phosphoric acid doped PBI membranes (para-PBI and 2OH-PBI) as well as PBI membranes containing ionic liquids (H3PO4/PMIH2PO4/PBI). These membranes are designed for higher-temperature fuel cell operation. In general, stronger short and long range interactions were observed in the 2OH-PBI matrix, yielding reduced proton transport compared to that of para-PBI. In the case of H3PO4/PMIH2PO 4/PBI, both conductivity and diffusion are higher for the sample with molar ratio 2/4/1. Finally, chapter 6 is devoted to the 31P NMR MAS study of phosphorus-containing structural groups on the surfaces of micro/mesoporous activated carbons. Two spectral features were observed and the narrow feature identifies surface phosphates while the broad component identifies heterogeneous subsurface phosphorus environments including phosphate and more complex structure multiple P-C, P-N and P=N bonds.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Physics
