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This is an exciting time in the history of vehicular transportation. The commercial introduction of hybrid electric vehicles coupled with the huge international effort to develop batteries and fuel cells for automotive use has made the dream of widespread electric vehicle use a real possibility. The last decade has seen the introduction of a variety of promising new materials for lithium rechargeable batteries, as well as a Federal initiative for the technological development of fuel cells. Reimer's research group, in collaboration with Professors Elton Cairns and Lutgard DeJonghe (MSE), as well as Dr. John Kerr at LBNL, has applied nuclear magnetic resonance (NMR) spectroscopy to the study of a variety of electrochemical systems, including proton-exchange membrane and intermediate temperature fuel cells, as well as Li-ion batteries. For example, Reimer's group was the first to obtain carbon-13 NMR data from commercial fuel cell electrocatalysts, and then used electroanalytical methods, combined with NMR, to elucidate how NMR chemical shifts speciate active surfaces on platinum catalysts. His group also elucidated the role the electron-nuclear hyperfine interaction plays in determining the NMR "chemical" shifts of Li in the complex oxides that comprise electrode materials for batteries. His group is exploring, in collaboration with Prof. Lutgard DeJonghe, so-called "Norby's Gap" proton conductors for intermediate temperature hydrogen/biofuel fuel cells. These studies involve multi-dimensional solid-state NMR, as well as pulse-field gradient and stray-field diffusion measurements. People Matthew Dodd, Megan Hoarfrost, Allison Engstrom, Eric Scott, Joel Stettler, Dr. Jian Feng. Representative Papers Electrocatalysis Proton Conductors Lithium Batteries |
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The Reimer group is part of the DOE "Center for Gas Separations Relevant to Clean Energy Technologies," a center devoted to fundamental studies of materials tailored for gas separations. The Center focusses on the synthesis of metal-organic framework, self-assembled polymers, and other nanostructered materials, their characterization at the atomic level of structure and sorbate dynamics, and computational studies that provide understanding of chemical interactions are a molecular level. Our principle contributions to this effort are multi-dimensional solids NMR methods for structure determination and a variety of dynamical studies with pulse field gradient and relaxometry methods. In addition we are developing new instrumentation for the rapid characterization of pore structure. People Dr. Sean Kong Representative Papers Ex-Situ |
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A particularly limiting feature of NMR spectroscopy and magnetic resonance imaging (MRI) is the miniscule magnitude of the expectation value for nuclear spin orientation: the Zeeman splittings between the nuclear spin energy levels are small relative to kT. Thus the vast majority of NMR and MRI methods are restricted to bulk systems. For this reason, considerable attention in the NMR/MRI community is focused on the development of methods for enhanced nuclear polarization. One strategy for overcoming the sensitivity limitations exploits the near-perfectly polarized electrons that can be generated in a number of ways, then uses the electron spin polarizations to effectively deliver high polarization to nuclei. Funded by an NSF NIRT, Professor Reimer, in collaboration with Professor Segalman and Prfs. Meriles and Tamargo at CCNY, are exploiting this strategy and have employed the optical excitation of organic and inorganic semiconductors and semiconductor-based nanostructures to provide electron spins that yield exotic NMR-observable nuclear spin populations. Our most recent results demonstrate an all-optical method of polarizing the bulk 13C nuclear spin system in diamond. People Jonathan King Representative Papers Nuclear Thermodynamics Nuclear Spintronics |
 
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In 2000 Prof Reimer began a collaboration with Professor Douglas Clark and Professor Jonathan Dordick (RPI) to use spectroscopic methods to study nonaqueous biocatalysis, i.e., applications of enzymes in organic media or nearly anhydrous environments. Nonaqueous biocatalysis, including enzymatic reactions in nearly anhydrous organic solvents, has emerged as a practical tool for chemical synthesis that exploits the exquisite chemo-, regio-, and enantio-selectivities demonstrated commonly by enzymes, yet avoids the limitations of aqueous enzymatic catalysis. Unfortunately, little is understood about the mechanistic details of non-aqueous biocatalysis. Reimer's role in the collaboration is to provide a host of liquid- and solid-state NMR techniques that are aimed at elucidating the mechanism whereby enzymes are activated for non-aqueous biocatalysis by their formulation with excipients. His students have shown, for example, that enzyme activity in organic solvents can be improved nearly 30,000-fold by including simple nonbuffer salts in the lyophilized enzyme. The group has also shown via deuterium NMR measurements that increases in enzyme-bound water mobility mediated by the presence of certain excipients act as a molecular lubricant that alters enzyme flexibility in a manner functionally similar to temperature. Greater flexibility may permit a larger degree of local transition-state mobility, reflected by a larger entropy of activation, for the salt-activated enzyme as compared with the salt-free enzyme. This increased mobility contributes to the dramatic increases in biocatalyst activity. Parallel studies of enzymes activated by solubilization show that the stabilization of the catalytic transition state plays just as important a role in activation in those formulations. People Michael Liszka Representative Papers Enzyme Catalysis |