English  |  正體中文  |  简体中文  |  Items with full text/Total items : 52146/60024 (87%)
Visitors : 5300841      Online Users : 77
RC Version 6.0 © Powered By DSPACE, MIT. Enhanced by NTHU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version
    National Tsing Hua University Institutional Repository > 理學院 > 化學系 > 博碩士論文  >  共軛性高分子之合成與性質鑑定及其在高分子發光二極體與奈米管之應用


    Please use this identifier to cite or link to this item: http://nthur.lib.nthu.edu.tw/dspace/handle/987654321/7878


    Title: 共軛性高分子之合成與性質鑑定及其在高分子發光二極體與奈米管之應用
    Other Titles: Syntheses and Characterization of Conjugated Polymers and their Applications towards Polymeric Light Emitting Diodes and Nano-tubes
    Authors: 巴樂書
    Description: 博士
    國立清華大學
    化學系
    Date: 2006
    Keywords: 高分子發光二極體
    奈米管
    Polymeric Light Emitting Diode
    Nano-tubes
    Abstract: 摘要
    共軛性高分子具有半導體性質,因而在許多元件的製備上,包括有機發光二極體、電激發光元件、光電池、薄膜電晶體以及高分子雷射等方面有著相當大的應用潛能。其中,共軛性高分子獨特的電激發光特性更是為有機發光元件顯示器科技發展上的一大推進。
    因此我們合成一系列單一取代的聚苯基乙炔poly(phenylacetylene)s (PPAs) 分別命名為P1、P2、P3、P4、P5和P6。透過過渡金屬催化劑WCl6以及有機金屬共催化劑Et3SiH於toluene溶劑下進行聚合即可獲得不錯的產率。P1 ~ P6為褐色到深紫色的固體且具有相當好的溶解性,可溶於toluene、chloroform、dichloromethane、THF、xylene等有機溶劑中。其分子量(Mw)分佈為40,000 ~ 500,000。由IR以及NMR光譜上進一步對其結構進行解析,可發現透過WCl6催化所得到的共軛性高分子多為反式結構,只有小於10 %的比例為順式結構。在TGA研究上,P1 ~ P6加熱直至350 oC才開始有裂解的現象產生,相較於傳統的poly(phenylacetylene) (PPA)具有較佳的熱溫定性。在THF溶劑中,P1 ~ P6的UV-vis吸收光譜相較於PPA有很大的紅位移吸收產生;而在螢光光譜研究上,P1、P4、P5 和 P6 有藍光放射(~ 414 nm),P2 和P3 則有紫光放射。
    此外,透過NbCl5與n-Bu4Sn共同催化聚合雙取代聚乙炔polyacetylene同樣具有很高的產率。此雙取代聚乙炔為亮螢光黃固體,其分子量約為282,776。在溶解度測試上,其幾乎可溶於大部分的有機溶劑例如toluene、chloroform、dichloromethane、THF、xylene等溶劑中。我們同樣利用IR以及NMR光譜確定其結構。由於其在對位位置具有phenylethynyl官能基,即使在386 oC溫度下也只有約略5%熱重損失,因此有良好的熱穩定性。雙取代聚乙炔的在THF溶劑中的UV-vis吸收約在292 nm,而其螢光光譜則顯示其有藍綠光放射。因其tolane
    和hexyl官能基所產生的立體障礙使其在固態光學的研究上並無分子團聚集的現象。共軛性高分子PhPO相較於原本的PPhA-6具有較佳的光學性質和熱穩定性。
    另一系列新型poly(phenyleneethynylene)同聚物 (PE-1和PE-2)與共聚物( PE-3和PE-7 )分別具有phenyl、fluorene、carbazole和pyrene聚合單位,透過Pd催化聚合可得到相當高的產率,並利用IR、NMR光譜和GPC確定其結構與分子量分佈。此一系列的高分子有相當良好的熱穩定性,經由熱重分析量測,在281 ~358oC氮氣氣氛下僅少於5 % 的重量損失。此聚合物於THF溶液中激發波長在其UV吸收最大值之波長位置下其螢光光譜顯示其有藍色及藍綠色之放射,聚合物從固體狀態轉換呈溶液狀態由於聚合物之分子聚集現象導致UV-vis 光譜及螢光光譜有紅位移的現象,溶液誘發分子聚集在PE-1與PE-2其UV-vis 光譜與 螢光光譜皆顯示強的分子間作用力,而PE-3、PE-5和 PE-6僅在螢光光譜顯示強的分子間作用力,而PE-4和PE-7在UV-vis 及螢光光譜皆顯示出弱的分子間作用力。
    另一系列新型poly(phenyleneethynylene)寡聚物分別具有alkyl 和alkoxy 側鏈基及fluorene、carbazole和pyrene聚合單位,透過Pd催化聚合可得到相當高的產率,此寡聚物在一般之有機溶液中具有相當好的溶解性如chloroform、toluene、ethyl acetate、THF、dichloromethane、DMSO、DMF等。利用不同之光譜進一步對其結構進行解析,熱重分析結果顯示其熱穩定溫度範圍由312 oC至485 oC也只有約略5%熱重損失且可維持相當高之重量即可保持80至40 %之重量,OPE-5及OPE-11之寡聚物熱性質顯示出nematic schlieren textures之液晶相,且OPE-6在光學顯微鏡下觀察出smectic focal textures結果。由於alkyl和alkoxy 推電子基性質之側鏈取代基效應及接受電子特性之carbazole聚合單位及富含電子之pyrene系統其UV-vis 光譜及螢光光譜顯示其應有之紅位移或藍位移的現象,在固體薄膜狀態之寡聚物在UV-vis 光譜及螢光光譜皆比其溶液狀態顯示紅位移的現象是由於在固態薄膜狀態下有較強之分子間之作用力。
    最後poly(phenyleneethylene)s PE-3及PE-6之聚合物應用於製備奈米高分子及奈米碳管之材料,以200 nm孔洞之氧化鋁薄膜作為模板,奈米碳管製備經由加熱700 oC於內含奈米結構之高分子管之氧化鋁薄膜模板,利用奈米結構之模板所合成出之奈米高分子管及奈米碳管為管壁平滑之圓型孔洞奈米管且具有良好的機械強度,當完全移除氧化鋁膜板後,奈米高分子管及奈米碳管之孔洞直徑為~200 nm與氧化鋁模版非常相近。由PE-6經鍛燒700oC後所得的耐米碳管具有turbostatic的特性。
    Abstract

    Conjugated polymers are organic semiconductors and, as such, are of great potential importance for device fabrication. Such devices include light-emitting diodes, light emitting electrochemical cells, photovoltaic cells, thin-film transistors, and plastic lasers. The discovery of electroluminescence in conjugated polymers gave an impetus to the development of light emitting devices for display technology.
    New monosubstituted poly(phenylacetylene)s (PPAs) P1-P6 were synthesized by using the transition metal catalyst WCl6 and organometallic cocatalyst Et3SiH in toluene at rt in good yields. The polymers produced were brown to dark purple solids and soluble in organic solvents such as toluene, chloroform, dichloromethane, THF, xylene etc. The weight-average molecular weight (Mw) was ranging from 4 × 104 to 5 × 105. IR and NMR studies confirmed the structure of the polymers. The stereo structure of the polymers was confirmed by 1H NMR and it can be concluded that WCl6 produces trans-rich polymers together with less than 10% cis-rich polymers. The polymers were found by TGA studies to begin losing weight at ca. 350 ℃ under nitrogen, which shows that P1-P6 are thermally more stable than poly(phenyl acetylene) (PPA). UV-visible spectra of P1-P6 showed large red-shifted absorption maximum as compared with that of PPA. The fluorescence spectra of polymers P1, P4, P5 and P6 showed blue emission (~414 nm), while P2 and P3 showed purple emission upon excitation of their THF solution.
    A new disubstituted polyacetylene was synthesized with the transition metal catalyst NbCl5 with the cocatalyst n-Bu4Sn in toluene at RT in good yield. The polymer was bright fluorescent yellow color solid with an Mw of ca. 2.8 × 105. The polymer was found to be highly soluble in most of the organic solvents such as toluene, chloroform, dichloromethane, THF, xylene etc. The structure of the polymer was confirmed by spectroscopic analysis such as NMR and IR. The polymer was thermally stable due to the presence of phenylethynyl group at the para-position, which showed 5% weight loss at about 386 ℃. The polymer showed absorption maximum at ca. 292 nm and the photoluminescence showed blue-green emission upon excitation at their absorption maximum in THF solution. Solid state absorption and emission showed no aggregation, due to the steric hindrance of the tolane and hexyl group on the polymer backbone. The optical and thermal properties of the polymer PhPO were found to be much better than the parent polymer PPhA-6.
    A series of new poly(phenylene ethynylene) homopolymers (PE-1 and PE-2) copolymers (PE-3 to PE-7), with phenyl, fluorene, carbazole and pyrene units, were synthesized by the Pd catalyzed coupling reaction in good yields. The structures of the polymers were confirmed by IR and NMR spectroscopies and their weight average molecular weights were measured by GPC in THF eluent. The polymers in general showed the temperature of 5% weight loss appeared at ca. 281-358 ℃. The polymers exhibited emission in blue region and blue-green-light in THF solution upon excitation at their absorption maximum. Due to aggregate formation, polymers showed red-shifted absorptions and emissions in their solid state films as compared with their solutions. Solvent-induced aggregation of PE-1 and PE-2 showed strong polymer chain interaction both in absorption and emission spectra. While the solvent-induced aggregation of polymers PE-3, PE-5, and PE-6 showed strong polymer chain interaction in the emission spectra and weak polymer chain interaction in the absorption spectra. Interestingly the solvent-induced aggregation of PE-4 and PE-7 showed very weak polymer chain interaction in both absorption and emission spectra.
    We have synthesized various oligo(phenylene ethynylene)s (OPEs) by Pd catalyzed coupling reaction with good yields, in which alkyl and alkoxy groups were introduced as side chains and fluorene, carbazole and pyrene were introduced as alternating aryl units in their chromophoric chain. The oligomers are highly soluble in most of the organic solvents such as chloroform, toluene, ethyl acetate, THF, dichloromethane, DMSO, DMF etc. The structure of the oligomers was confirmed by means of various spectroscopic analyses. The oligomers in general showed the weight loss temperature of 5% appeared at ca. 312-485 ℃, and the weight retention at 900 ℃ was much higher, i.e., 80 to 40%. The thermal properties of oligomers showed liquid crystalline phases for OPE-5 and OPE-11 and they showed nematic schlieren textures, while OPE-6 showed smectic focal conic textures upon cross-polarized optical microscope observation. The solid state film of oligomers showed red-shifted emission and absorption from their solution spectra due to aggregate formation in the solid state.
    Finally, we have synthesized polymer nanotubes and carbon nanotubes using the poly(phenylene ethynylene)s of PE-3 and PE-6 using alumina membrane template with an average pore size diameter of ca. ~200 nm. The carbon nanotubes were prepared by heating the alumina membrane template containing the polymer tube nanostructures at 700 ℃. By this template nanostructuring method, both polymer nanotubes and carbon nanotubes were formed with a very good mechanical strength. The tubes are circular hollow and the surface was very smooth. After complete removal of the alumina membrane, the average outer diameter of polymer nanotubes and carbon nanotubes were in well agreement with the pore diameter (~200 nm) of alumina membrane template. The carbon nanotubes prepared from polymer PE-6 at 700 ℃ are turbostatic in nature.
    URI: http://nthur.lib.nthu.edu.tw/handle/987654321/7878
    Source: http://thesis.nthu.edu.tw/cgi-bin/gs/hugsweb.cgi?o=dnthucdr&i=sGH000907408.id
    Appears in Collections:[化學系] 博碩士論文

    Files in This Item:

    File SizeFormat
    GH000907408.zip61260KbUnknown115View/Open


    在NTHUR中所有的資料項目都受到原著作權保護,僅提供學術研究及教育使用,敬請尊重著作權人之權益。若須利用於商業或營利,請先取得著作權人授權。
    若發現本網站收錄之內容有侵害著作權人權益之情事,請權利人通知本網站管理者(yzchen@lib.nthu.edu.tw),管理者將立即採取移除該內容等補救措施。

    SFX Query

    與系統管理員聯絡

    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback