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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

White Light Emitting Diodes of Non-fully Conjugated Coil-like Polymer Doped with Derivatized Multi-wall Carbon Nanotubes

Chang, Yi-jyun 28 July 2006 (has links)
Luminescent emission of non-fully conjugated homopolymers was successfully demonstrated as light emitting diodes (LEDs) in this research. Coil-like heterocyclic aromatic poly[2,2-(2,5-dialkyloxyphenylene)-4-4¡¦-hexafluoroisopropanebibenzoxazo- les] (6F-PBO-CnOTpA, with n = 10, 15, and 20) was synthesized, and polymer composites of 6F-PBO-CnOTpA was in-situ synthesized with acidified multi-wall carbon nanotube (MWNT- COOH). The non-fully conjugated coil-like heterocyclic aromatic homopolymer was synthesized by reacting 2,2,bis-(3-amino-4-hydroxy[henyl]-hexafluoropropane with 2,5-dialkyloxyterephthalic acid (CnOTpA) for 6F-PBO-CnOTpA, with n = 10, 15, and 20. In addition, MWNT was acidified for connecting the carboxylic group (-COOH) to reduce its aspect ratio and entropy induced aggregation. MWNT-COOH was analyzed using elemental analysis (EA) and viscometry to validate the effects of acidification period. The EA result seemed to suggest that the oxygen content increased, and the carbon and the hydrogen contents decreased with acidification period. The inherent viscosity (£binh) decreased according to acidification period suggesting that the aspect ratio was indeed decreased. A hole transport layer of PEDOT¡GPSS was applied for multi-layer LEDs,. The LEDs all showed a threshold voltage about 4 V also for the composites of 6F-PBO-CnOTpA in-situ polymerized with MWNT-COOH. The 6F-PBO-CnOTpA LEDs with and without MWNT-COOH showed an electroluminescence emission range of 400 to 750 nm.

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