Materials characterization of a photochemically produced conducting polymer /
An investigation was made to characterize photopolymerized polypyrrole. The photopolymerization method used was a novel process which allows the direct polymerization of a conductive polymer on any type of substrate. This process involves only three steps: casting a solution containing monomer and...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=742744751&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | An investigation was made to characterize photopolymerized polypyrrole. The photopolymerization method used was a novel process which allows the direct polymerization of a conductive polymer on any type of substrate. This process involves only three steps: casting a solution containing monomer and oxidizing agent; illuminating the cast solution; and rinsing off the excess solution. The investigations were carried out by targeting three major areas of research. These included the chemical processes or reactions involved at all levels, the physical and physico-chemical properties of the polymer, and testing of photopolymerized polypyrrole based electronic components. Chemical studies designed to identify the best components for the prepolymer solution indicated that silver (I) cation was the best electron acceptor and nitrate was the best associated counterion. Further investigation revealed a 1:1 pyrrole:silver nitrate mole ratio with added acetonitrile as a solvent yielded the highest conductivity, 40 S/cm. Investigations designed to identify possible photoinitiators and other additives were carried out. It was determined that adding to the prepolymer solution could improve properties such as the curing time or pattern resolution, however, in every case the conductivities of the resulting films or coatings were lowered. Different deposition methods were investigated including the casting of solution and subsequent light exposure. It was determined that spin casting the prepolymer solution yielded the most promising results. Exposure investigations were done using an intense UV lamp, argon ion laser, ytterbium aluminum garnet (YAG) laser, and an electron beam. Each method of exposure had corresponding advantages. It was determined that the best method of exposure is a function of the target application. Thermal analysis was performed using differential scanning calorimetry, thermogravimetric analysis, and thermomechanical analysis. Testing indicated that the cure was irreversible, that the polymer was very hygroscopic, and that photopolymerized polypyrrole had a variable expansion coefficient over three temperature ranges. The morphology was investigated by scanning electron microscopy (SEM) and atornic force microscopy (AFM). Electrical characterization was carried out on the photopolymerized polypyrrole by testing polypyrrole based resistors. The resistors were found to be reproducible and had very good stabilities. |
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| Item Description: | Vita. "Major Subject: Interdisciplinary Engineering". |
| Physical Description: | xvii, 170 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |