Characterization of conducting polymer films by ²⁵²Cf plasma desorption mass spectrometry /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Thin conducting polymer films such as polypyrrole (PP) and poly-3-methylthiophen (PMT) were made as matrices for ²⁵²Cf Plasma Desorption Mass Spectrometry (PDMS). The properties of these films were characterized by a variety of techniques. The UV-Vis and FT-IR spectra of PMT films showed the evolution of the band structure when oxidation or reduction proceeded as predicted in the literature. The XPS composition analysis of the film indicated that the counterions were uniformly incorporated. The influence of the oxidation level of PMT 252 films on ion yields in ²⁵²Cf PDMS was studied. The yields of molecular ions of surface adsorbates and polymer fragments were higher if the matrix was in the reduced, non-conducting form. The kinetic energy of several fragment ions from polymer chains was measured. It followed an improved Maxwell-Boltzmann distribution if the evolution and decay of the incident ion track (fission track) were considered. From this measurement, it was observed that the fission track in an electrically insulating matrix was more highly excited. This result was in agreement with observed higher ion yields from non-conducting matrices. Electronic excitation of the fission track in the matrix lasted longer if the matrix was an insulator. In this case, Coulomb repulsion forces built up in the ionized core area of the track causing more intensive fragmentation as well as surface desorption. The redox process of PMT films was investigated by monitoring the yield of the anion, the 252 counterion in the film, using ²⁵²Cf PDMS. A hysteresis of the counterion concentration in PMT films as the function of the oxidation potentials was observed and interpreted in terms of the N-shaped free energy change in the redox process of conducting polymers. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Chemistry." |
| Physical Description: | xix, 246 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |