比較PU及PVDF黏結劑應用於電容去離子技術去除水中銦離子之研究

The Removal of Indium Ions from Aqueous Solutions via the Capacitive Deionization using Polyurethane Binder and Polyvinylidene Fluoride Binder

黃仁義(REN-YI HUANG)

指導教授 ： 莊順興

朝陽科技大學/理工學院/環境工程與管理系/碩士(2016年)

摘要

本研究以自製聚氨酯(polyurethane, PU)黏結劑及聚偏氟乙烯(polyvinylidene fluoride, PVDF)黏結劑探討改質之TiO2/AC活性碳電極，使用電容去離子技術(capacitive deionization, CDI)以自組式CDI模型廠進行銦離子吸附。
實驗第一部分結果顯示，以四種不同碳材進行循環伏安法(cyclic voltammetry, CV)及電化學組抗頻譜(electrochemical impedance spectroscopy, EIS)所測得出石油焦活性碳(AC-p)之CV及EIS皆具備良好之電化學特性，PU及PVDF之活性碳電極電吸附容量可達到122.4 F/g及136.3 F/g，由波德圖(Bode plot)亦顯示出AC-p具有最低電子阻抗並以垂直電容形式上升，可證明PU黏結劑之活性碳電極電容效能與PVDF之活性碳電極效能相近，後續以TiO2作AC-p改質實驗用於銦吸附實驗。
第二部分探討四種不同TiO2改質活性碳之實驗，以(microwave-assisted ionothermal synthesis of titanium, MAIS TiO2)/AC-p所合成之複合碳電極其電吸附容量及EIS電化學特性皆達到良好之電容效能，且由奈式圖(nyquist plot)之結果證明MAIS TiO2/AC-p於低頻阻抗區域電子阻抗最低成垂直電容形式上升，可比擬純碳材活性碳電極。
本研究第三部分以PU及PVDF黏結劑之MAIS TiO2/AC-p複合碳電極進行不同濃度之CDI銦吸附實驗，實驗數據可說明於低濃度下PU之複合碳電極具有良好之吸附效果，高濃度為PVDF效果較佳，且從等溫吸附模式曲線亦說明低濃度適用Langmuir模式，高濃度則適用Freundlich模式，說明PU黏結劑之黏結性能可取代PVDF。

關鍵字

電容去離子技術 ； 聚氨酯 ； 聚偏氟乙烯 ； 銦 ； 微波離子熱合成 ； 二氧化鈦

並列摘要

This research is about experimenting self-made polyurethane (PU) binder and polyvinylidene fluoride (PVDF) binder on TiO2 activated carbon electrode by performing Indiun (In^(3+))electrosorption using self-assembled CDI module.
The result obtained from the first part of the experiment indicated that petroleum coke (AC-p) has a higher electrochemical characteristic after performing cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) on four types of activated carbon (AC). The electrosorption capacity of PU- activated carbon electrode and PVDF-activated carbon electrode was able to reach 122.4 F/g and 136.3 F/g. As shown in Bode plot, AC-p has the lowest internal resistance and highest electricity conductivity, proving that the efficiency of PU-activated carbon electrode is closely similar to PVDF-activated carbon electrode. From the analysis, the most appropriate type of electrode materials to be used in CDI application is TiO2/AC-p.
The second part of the experiment explored on four different TiO2/AC. An enhancement in electrosorption capacity and EIS electrochemical characteristic was observed for the TiO2/AC-p prepared by a two-step microwave-assisted ionothermal synthesis (MAIS) method. The result from nyquist plot indicated that MAIS TiO2/AC-p has the smallest diameter of the semi-circle, matching the efficiency of a pure activated carbon electrode.
Next, the third part of the experiment focused on using different concentration of PU and PVDF MAIS TiO2/AC-p to perform CDI Indiun electrosorption. At lower concentration, it is beneficial to use PU activated carbon electrode. On the contrary, at higher concentration, PVDF is more favorable. By using the Langmuir and Freundlich model, the data obtained has shown that the efficiency of PU is closely similar to PVDF which increase the possibility of replacing PVDF with PU.

並列關鍵字

capacitive deionization ； polyurethane ； polyvinylidene fluoride ； Indium ； microwave-assisted ionothermal synthesis ； titanium dioxide

參考文獻

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