| Abstract: | 導電性高分子 poly(3,4-ethylenedioxythiophene) (PEDOT)由於其低能帶間隙､氧化還原活性佳､穩定性好､電導?高和明顯的電致變色等特性﹐在過去的二十??已受到大?的關注。雖然EDOT 通過化學或電化學聚合方法合成導電性PEDOT 被視為簡單且?價的過程，但通常為在酸性條件下進?，合成得到的PEDOT 呈?溶於水及一般溶劑﹐因而加工性能差，限制?它們的實際應用。最近，?聚合導電性高分子已被證明可以克服這些問題，並提供?一種可以直接合成結構均勻､水可溶性好的PEDOT。在水溶液中進?的?聚合反應﹐為?維持作為催化劑的辣根過氧化?(HRP)的活性﹐通常在溫和的條件下；然而，卻是一個非常耗時的過程，並且產生低分子?的PEDOT 產物。?同於一般對?催化聚合PEDOT 反應機制的?解﹐我們初步的研究結果表明辣根過氧化?在 EDOT 的聚合中主要扮演激發EDOT 單體形成自由基而達到啟動聚合反應的角色。 PEDOT 高分子鏈的延伸則可以通過在酸性條件下的加熱過程實現。為此，我們計劃通過本計畫的執?進一步探討?催化聚合PEDOT 形成的機制。由此﹐我們將建??有效的聚合條件，設計?步驟?催化反應過程﹐以獲得具備高電導?､高溶解性及加工性的 PEDOT。與此同時，我們還將討?使用?子液體及球型SBA-15 中孔微?固定辣根過氧化?對PEDOT 合成過程的貢獻。最後，我們將通過構建柔性微電極及進?必要的修飾，達到可於監測和加強?經細胞軸突生長活性的目的﹐以探?導電性高分子PEDOT 未?的應用。
During the past two decades, the conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), has received a significant amount of attention because of its low bandgap energy, remarkable redox-activity, good stability, high conductivity, and pronounced electrochromic properties. PEDOT has the potential applications in many areas that utilize its excellent optical and conductive properties. Although chemical and electrochemical polymerizations of EDOT are considered as simple and inexpensive approaches for the synthesis of conductive PEDOT, they are generally carried out in an acid condition, and the synthesized PEDOT usually possess low solubility in solvents and inadequate processability, which limit their practical applications. Recently, enzymatic polymerization has been proved to overcome these problems and provides an alternative approach to synthesize water soluble PEDOT with uniform structures. For enzymatic polymerization in an aqueous solution, the polymerization is usually conducted under mild condition in order to maintain the activity of the Horseradish Peroxidase (HRP), which is used as the catalyst; however, it is normally a time-consuming reaction and often produces low molecular weight of PEDOT. In different from the common knowledge on the mechanism of enzymatic polymerization, our preliminary results have suggested that the major role of HRP during the polymerization of EDOT is to initiate the polymerization by oxidizing EDOT to form the radical monomer. The propagation of PEDOT may require the heating procedure under an acid condition. We therefore plan to carry out the current project to further explore enzymatic polymerization of EDOT. Accordingly, we will establish more effective conditions and design a two-step enzyme catalyzed process in order to obtain the conductive PEDOT with high conductivity, solubility, and processibility. Meanwhile, the contributions of using ionic liquid and HRP immobilization in the spherical SBA-15 will be discussed. Finally, we will make an effort to seek the potential application of the enzymatic synthesized PEDOT in constructing flexible microelectrode and proper modifications, which may be used for the monitoring and enhancing the neurite outgrowth bioactivity in neuron cell. |
