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Title: | 聚(丁基紫精)薄膜的電化學穩定性改善與電致變色元件應用 Improving the electrochemical stability of poly(butyl viologen) thin films for electrochromic devices |
Authors: | Shu-Ming Liu 劉書銘 |
Advisor: | 徐善慧(Shan-hui Hsu) |
Co-Advisor: | 何國川(Kuo-Chuan Ho) |
Keyword: | 電致色變元件,微電極,掃描電化學顯微鏡,表面修飾,長期穩定性,聚紫精,電化學石英晶體微天平, Electrochromic device,Electrochemical quartz crystal,Poly(butyl viologen) microbalance,Redox stability,Scanning electrochemical microscopy,Indium tin oxide,Surface modification., |
Publication Year : | 2019 |
Degree: | 碩士 |
Abstract: | 近年來,由於全球變暖問題,節能成為一個重要的課題。 電致變色是電活性材料的氧化還原反應的現象,具有可逆的顏色變化,並且可能引起材料的吸收光譜的顯著變化。
本研究以電變色材料聚丁基紫精(PBV)進行研究。聚丁基紫精(PBV)是具有三種氧化還原狀態的有機聚合物,即二陽離子(PBV2+),自由基陽離子(PBV•+)和二還原態(PBV0)。最穩定的形式是紫色的二陽離子PBV2+。而PBV•+和PBV0分別為無色和棕色。通過對其單體雙(4-氰基-1-吡啶基)丁烷二溴化物(BVBr2)的自由基陽離子狀態施加電位,可以將PBV電聚合到ITO玻璃上。為了改善PBV膜的電化學性質,需要在電解液中添加Fe(CN)64-。 良好的去色/著色的電化學可逆性對於電致變色材料的應用是非常重要的。在第3章中,對電聚合製備含亞鐵氰化物的聚(丁基紫精)(PBV:fc)薄膜,進行研究並且比較添加或不添加亞鐵氰化鉀(K4Fe(CN)6)在電解質中的的氧化還原性質變化。運用循環伏安法(CV)和UV-Vis光譜技術研究PBV:fc薄膜的電化學和電致變色性質。透過電化學石英晶體微天平(EQCM)技術研究了PBV:fc薄膜在氧化還原反應過程中的質量變化,此外,掃描電化學顯微鏡(SECM)可以用來證實Fe(CN)64-陰離子進入/跑出PBV:fc薄膜的穩定性。結果表示,電解質中額外加入K4Fe(CN)6,可以有效地改善PBV:fc薄膜的氧化還原可逆性。我們推測提高PBV:fc薄膜的去色/著色穩定性的原因可能是受到反應過程中Fe(CN)64-電荷平衡的影響。最後,使用PBV:fc薄膜和普魯士藍(PB)薄膜製成互補電致變色器件(ECD),研究亦發現含有K4Fe(CN)6的電解質的ECD比沒有K4Fe(CN)6的電解質有更好的透射率與穩定性。 在第4章中,推測在水溶液中的PBV:fc薄膜吸附性可能是導致收縮的另一個原因,並降低了長期穩定性。此章節的目標是提高PBV:fc薄膜和由PBV:fc薄膜組成的ECD的氧化還原穩定性和長期穩定性,將表面改質的方法運用在修飾ITO玻璃上。首先先將羥基修飾在ITO玻璃上再使用4-氰基苯酚(P-CN)和芐基膦酸(BPO3)修飾基通過縮合反應形成化學鍵結在ITO 玻璃上,製備成P-CN-ITO玻璃和BPO3-ITO玻璃。 PBV:fc薄膜電聚合在P-CN-ITO玻璃和BPO3-ITO玻璃上,分別形成P-CN-PBV:fc薄膜和BPO3-PBV:fc薄膜。此外,PBV:fc薄膜與修飾的ITO玻璃之間形成共價鍵提升吸附力,並且成功的提高電致變色的性質。 在有修飾的PBV:fc薄膜組成的ECD中也增強電性的長期穩定性,其長期維持的穿透度變化亦在修飾的ECD中有效的提升。 Energy conservation becomes an important topic owing to the global warming issue. Electrochromism is the phenomena of redox reactions of electroactive materials in company with reversible color changes, and which might cause significant variations in the absorbance spectra of the materials. Poly(butyl viologen) (PBV) is an organic polymer that has three redox states, namely, di-cation (PBV2+), radical-cation (PBV•+), and di-reduced state (PBV0). The most stable form is the di-cation, PBV2+, which is purple. PBV•+ and PBV0 are colorless and brown, respectively. PBV can be electropolymerized onto the ITO glass by applying a potential to the radical-cation state of its monomer, bis(4-cyano-1-pyridino)butane dibromide (BVBr2). In order to improve the electrochemical properties of the PBV film, addition of Fe(CN)64- in the deposition bath is necessary. High bleaching/coloring electrochemical reversibility is crucial for practical applications of an electrochromic material. In Chapter 3, ferrocyanide-containing poly(butyl viologen) (PBV:fc) thin films were prepared by electropolymerization, and subsequently investigated and compared their redox properties by using the electrolyte with and without the addition of potassium ferrocyanide (K4Fe(CN)6). Electrochemical and electrochromic properties of the PBV:fc thin films were studied by using cyclic voltammetry (CV) and UV-Vis spectroscopy techniques. The mass changes of the PBV:fc thin films during their redox reactions were studied by using electrochemical quartz crystal microbalance (EQCM) technique. In addition, the scanning electrochemical microscope (SECM) studies confirmed the stable anion insertion/extraction of Fe(CN)64- within a PBV:fc thin film. The obtained results indicate that the redox reversibility of the PBV:fc thin film can be effectively improved by the addition of K4Fe(CN)6 in the electrolyte. It is deduced that the enhancement of bleaching/coloring stability of the PBV:fc thin film is affected by Fe(CN)64- charge balance during the reactions. Complementary electrochromic devices (ECDs) using the PBV:fc and Prussian blue (PB) thin films were fabricated. Finally, the ECD with the electrolyte containing K4Fe(CN)6 shows the superior transmittance modulation stability than the one without K4Fe(CN)6. In Chapter 4, the adhesion is supposed that another reason leaded to shrink the PBV:fc thin film in the water solution and decreased the long-term stability. We aim at improving the redox stability and long-term stability of PBV:fc thin film and based ECDs. The surface modification method was introduced into the ITO glass preparation. In the beginning, the hydroxyl group bond on the ITO glass and the chemical bond formed between ITO glass and modifier, 4-cyanophenol (P-CN) and benzyl phosphonic acid (BPO3) by condensation reaction. The P-CN-ITO glass and the BPO3-ITO glass were made. PBV:fc thin film was electropolymerized on the P-CN-ITO glass and the BPO3-ITO glass, forming P-CN-PBV:fc thin film and the BPO3-PBV:fc thin film, respectively. In addition, the formation of covalent bond between PBV:fc thin film and modified ITO glass promoted the adhesion force, and the EC property was successfully enhanced. The ECDs also showed the enhancement on the long-term switching stability based on PBV:fc thin film electrode. The retention of its initial ΔT in modified ECDs are higher than without modified ECD. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/72744 |
DOI: | 10.6342/NTU201902009 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 高分子科學與工程學研究所 |
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