高導電度EDOT/Aniline混成共聚高分子： 原位氧化聚合、特性及其應用之研究

Abstract

本研究利用化學氧化原位聚合的方式合成EDOT單體與苯胺單體的高導電性共聚物薄膜，使用氧化劑Fe(OTs)3及Imidazole來與Fe(OTs)3作用，整個系統的反應是在甲醇溶液中進行。我們改變各個變數，如EDOT/Aniline(和Aniline/EDOT)、IM/Monomers及Fe(OTs)3/Monomers的莫耳比例，來探討其對導電度、光學性質及表面形態的影響，並找出各個變數在導電性最佳情況下的比例。在最佳情況下，其導電度比利用相同方法所聚合出的PEDOT及聚苯胺高出2~3倍。此導電度的提升是因為添加了EDOT單體或苯胺單體改變了共聚合反應的反應速率，而使共聚物薄膜的表面較均勻平坦。我們可藉由紫外光可見光光譜得知共聚物薄膜的摻雜程度。利用傅立葉轉換紅外線光譜，我們證實了EDOT單體和苯胺單體共聚物的生成。 製備氧化鋅奈米柱/共聚物複合薄膜可分為三個步驟：共聚物薄膜的合成、將氧化鋅晶種附在共聚物薄膜的表面上、以水熱法成長氧化鋅奈米柱。我們可利用X光繞射光譜儀得知氧化鋅的結晶情形，及利用掃描式電子顯微鏡得知氧化鋅奈米柱的排列情況。當氧化鋅奈米柱成功形成在共聚物薄膜的表面上，即可加強酸鹼緩衝能力。

In this study, highly conductive copolymer films of 3,4-ethylenedioxythiophene (EDOT) and aniline were synthesized by chemical oxidative in situ copolymerization using iron(III) p-toluenesulfonate (Fe(OTs)3) as an oxidant and imidazole (IM) coordinating with Fe(OTs)3 in methanol. We investigated the effect of each variable such as the molar ratios of Aniline/EDOT (and EDOT/Aniline), IM/Monomers and Fe(OTs)3/Monomers on the conductivity, optical property, and surface morphology of the copolymer films. These parameters were optimized to maximize conductivities which are 2~3 times higher than PEDOT and polyaniline films synthesized by the same method. The enhancement of conductivities for copolymer films was due to the fact that the addition of aniline or EDOT changed the copolymerization rate, leading to a more uniform surface morphology. The UV-Visible absorption spectra also illustrated the doping level of copolymer films. From the study of FTIR spectra, we confirmed the formation of copolymer of EDOT and aniline. The ZnO nanorods/copolymer composite films were prepared by a three-step process: synthesis of copolymer films, deposition of ZnO seeds on copolymer films, and hydrothermal growth of ZnO nanorods. The crystallinity and morphology of ZnO nanorods on copolymer films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. After growing ZnO nanorods on the copolymer films, the pH buffering ability could be improved.