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| MATTHEW P. ESPE |
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Associate Professor
B.S., 1984, Illinois State University
M.S., 1986, Illinois State University
Ph.D., 1993, Michigan State University
Postdoctoral fellow, 1993-1996, Washington University (St. Louis) |
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Office: KNCL 221
(330) 972-6060 |
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Lab: KNCL 219
(330) 972-8389 |
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| Email: espe@uakron.edu |
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| Website: |
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| Research Interest |
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The research focus of my group is the characterization of the structure and dynamics of macromolecules. The goal is to understand microscopic (molecular level) properties of these systems and correlate them with the materials macroscopic properties. The primary tool for these investigations is solid-state NMR. The solid-state NMR (SSNMR) techniques being used include magic-angle spinning, dipolar recoupling and the application of state-of-the-art 1, 2 and 3 frequency experiments in both 1 and 2 dimensions.
Polymers
With solid-state NMR, polymer systems can be studied in their functional forms of solids, powders, films and fibers without a molecular weight restriction. One of the systems under study is polyaniline, a member of the group of conducting organic polymers. Under many conditions, polyaniline is partially or fully amorphous and standard techniques for determining structure, such as X-ray diffraction, are not applicable. We are using recently developed SSNMR dipolar recoupling techniques to measure internuclear distances to determine interchain distances, chain/dopant distances and the arrangement of dopant molecules. This information is being used to understand structural aspects of polyaniline, such as chain packing, that control the polymers conductivity.
Conjugated aromatic polymers also are being synthesized by using an enzyme as the catalyst. Peroxidases - soluable, heme-containing enzymes - oxidize phenols and aromatic amines to generate polyphenols and polyanilines. Reaction conditions and solvent systems capable of sustaining enzyme activity and polymer solubility are being developed, yielding high molecular weight polymers.
Inorganic Nanofibers
Nanometer diameter fibers of Al2O3 and CdSe are being synthesized and combined with conjugated polymers to form composites with photovoltaic capabilities or enhanced strength. The fiber composition and structure, as a function of synthetic conditions and post processing procedures, are being determined by 27Al, 113Cd and 77Se SSNMR. The critical portion of these composites is the interface between the polymers and nanofibers. The size, composition and structure of the interface are being characterized by using a range of SSNMR techniques. |
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| Selected Publications |
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J. E. Yoo, J.L. Cross, T. L. Bucholz, K. S. Lee, M.P. Espe, Y.-L. Loo, Processing-Structure-Property Relationships of Polyaniline Templated by Polymer Acid:The Role of Polymer Acid Molecular Weight, J. Mater. Chem., 2007, 17, 1268–1275.
“Observation of a Deuterium NMR Knight Shift in Conductive Polyaniline,” Goddard, Y.A.; Vold, R.L.; Cross, J.L.; Espe, M.P.; Hoatson, G.L., J. Chem. Phys, 2005, 122, 054901.
“Acid Distribution in Phosphonic Acid Doped Polyaniline by Solid-State NMR,” Young, T. L.; Cross, J.L. and Espe, M. P. , Macromolecules, 2003, 36, 5891.
“Sonicated Assisted Growth of Fluoro-Phosphate Films on Alumina Surfaces,” McNatt, J. S.; Morgan, J. M.; Farkas, N.; Ramsier, R.D.; Young, T.L.; Cross, J. L.; Espe, M.P.; Robinson T.R. and Nelson, L.Y., Langmuir, 2003, 19, 1148.
“Effect of Elevated Temperature on the Reactivity and Structure of Polyaniline,” Mathew, R.; Yang, D.; Mattes, B.R. and Espe, M.P., Macromolecules, 2002, 35, 7575.
“Application of Solid-State NMR to Characterize the Interaction of Gel Inhibitors with Emeraldine Base Polyaniline,” Young, T.L.; Yang, D.; Mattes, B.R. and Espe, M.P., Macromolecules, 2002, 35, 5565.
“A Solid State NMR Characterization of Cross-linked Polyaniline Powder,” Mathew, R.; Mattes, B.R. and Espe, M.P., Syn. Metals, 2002, 131, 149.
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