A new neutral state green polymer, poly (2,3-bis(4-tert-butylphenyl)-5,8-di(1H-pyrrol-2-yl) quinoxaline) (PTBPPQ) was synthesized and its copolymer with bis(3,4-ethylenedioxythiophene) (BiEDOT) and 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-dodecyl-2H-benzo [1,2,3] triazole (BEBT) were produced. Finally polymers&rsquo / potential use as an electrochromic material was investigated. Electrochromic properties of the polymers were investigated by several methods including spectroelectrochemistry, kinetic and colorimetry studies. Key properties of conjugated polymers such as band gap, maximum absorption wavelength, the intergap states that appear upon doping and evolution of polaron and bipolaron bands were investigated via spectroelectrochemistry experiments. Switching times and optical contrasts of the homopolymer and the copolymer were evaluated via kinetic studies. Copolymer of TBPPQ with BiEDOT and BEBT were electrochemically synthesized and characterized. Resulting copolymer films have distinct electrochromic properties and revealed multichromism through the entire visible region. Although BiEDOT and BEBT have different oxidation potentials, the resulting copolymers have very similar redox behaviors. In a monomer free solution, both copolymers show four colors from purple, gray, light green to transmissive blue with the variation of the applied potential. Copolymerization with BiEDOT and BEBT not only decreases the band gap, Eg, but also enhances the electrochromic and optical properties. Hence, electrochemical copolymerization is considered to be a powerful tool to improve the electrochromic properties of quinoxaline derivatives. It should be noted that PTBPPQ is one of the few examples of neutral state green polymeric materials with superior switching properties. Hence, PTBPPQ can be used as a green polymeric material for display technologies.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12610904/index.pdf |
| Date | 01 September 2009 |
| Creators | Celebi, Selin |
| Contributors | Toppare, Levent Kamil |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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