Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/59085
標題: 固定離子界面活性劑之離子交換薄膜系統界面與質傳行為之研究
Interfacial Phenomena and Mass Transfer of Ionic Surfactant-Immobilized Ion-Exchange Membrane System
作者: 孫幸宜
關鍵字: 應用研究
Ion-exchange membrane
化學工程類
離子交換薄膜
離子界面活性劑
界面現象
界達電位
質傳
疏水性固相萃取
Ionic surfactant
Interfacial phenomena
Zeta potential
Hydrophobic solid-phase extraction
摘要: 應用層析分析微量樣品目前最常搭配使用疏水性固相萃取前處理濃縮方法。本國際合作研究計畫與美國西肯德基大學化學系Conte教授合作,使用多孔性離子交換薄膜為固體相基材,吸附固定離子界面活性劑,而製備成疏水性薄膜,以發展一簡易而有效的疏水性固相萃取方法。以薄膜取代樹脂,可避開樹脂填充管柱的孔洞內擴散或高壓降等問題,或是樹脂壓疊成圓片後於操作時脫落流失等現象,改善其經濟效益。先前合作的經驗中,不管是陰離子界面活性劑固定至陰離子交換薄膜或陽離子界面活性劑固定至陽離子交換薄膜的研究,已獲得不錯的固相萃取成效。但我們亦發現到此技術的一些癥結點,因此希望能更進一步的探討與改善。本計畫第一年度重點為離子界面活性劑固定於離子交換薄膜的界面行為研究,因界面活性劑於薄膜界面的不同排列將影響後續疏水物質的吸附成效,故值得深入探討。有鑒於先前研究中陰、陽離子交換薄膜經熱重分析後顯示其界面行為不同,且達到固定化平衡兩者所需時間亦不同,因此本計畫建議使用電滲透法與流線電位法量測界面活性劑吸附固定前後的薄膜界達電位,以了解界面活性劑是否已順利固定上薄膜,並用以判斷不同條件下界面活性劑固定上薄膜的界面行為(如:單層或雙層)。此年度最終目的希望能精確獲得離子界面活性劑固定率分別為50、100、150%時的進料量與吸附固定時間等條件,以製備疏水性強的薄膜吸附劑(固定率100%)與同時具備兩種吸附作用力(疏水作用與靜電吸引,固定率50%或150%)的薄膜吸附劑,而不同的薄膜吸附劑將可應用至不同的疏水物質之固相萃取程序。本計畫第二年度的目標為探討不同薄膜模組設計下的質傳行為及對固相萃取成效之影響。本計畫建議採用圓管狀模組設計,將一片薄膜捲於一實心矽膠圓柱管外,可嘗試捲成一圈或捲成多圈(捲筒型式),再塞入圓管狀模組中,以進行流動固相萃取實驗。所獲得之固相萃取成效與質傳行為,將與圓片型模組結果做比較。另外,本計畫建議推導圓管狀薄膜模組的質傳方程式,以實際例子模擬,並與實驗結果比較,以了解此模組設計下影響質傳行為的可能因素。最後,本計畫希望將第一年度離子界面活性劑吸附固定於離子交換薄膜的實驗一倂以流動操作方式進行,建議以所得的最佳模組設計進行此部分實驗,並尋找最佳操作流量與時程。如此,使整套薄膜吸附劑製備與固相萃取程序完全在流動操作下進行,既能節省時間,亦可避開污染的可能性,將更符合經濟效益。
Hydrophobic solid-phase extraction (SPE) is a commonly adopted method to raise theconcentration of low-level analytes above chromatography detection limits. With thecollaboration of Prof. Eric Conte at Western Kentucky University, ion-exchange membraneswere successfully employed as the substrate to immobilize long-carbon-chain ionicsurfactants and hence form a hydrophobic SPE adsorbent. Both anionic surfactant- andcationic surfactant-immobilized membranes could achieve good performance. However,further investigation and improvement on this SPE method is still required.Proposed in the first year of this collaborative project is the intensive study on theinterfacial properties of immobilized surfactants, which is a key factor affecting thesubsequent hydrophobic analyte adsorption. Both electroosmosis and streaming potentialmethods are suggested for determining the membrane zeta potential before and after the ionicsurfactant immobilization. The parameters to be investigated include surfactant chain length,feed surfactant amount, and immobilization time. The results will be compared with thoseusing elemental analysis and thermogravimetric analysis in order to thoroughly understandthe arrangements of immobilized surfactants on membrane surface (e.g. single or bi-layer).The ultimate aim is to find the optimal conditions for preparing the hydrophobic SPEmembranes with different immobilization percentages such as 50, 100, and 150%. Themembrane with 100% immobilization will exhibit high degree of hydrophobicity, whereas themembrane with 50 or 150% immobilization will own two functionalities -hydrophobic andelectrostatic binding sites. These membranes could be suitable for different analytes.In the second year this project will focus on the mass transfer and SPE performances fordifferent membrane module designs. To overcome the disadvantage of short residence time inthe membrane disc module design, a tubular module design is proposed. A piece of membranewill be wound around a central tube in the form of either a single layer or multi-layers, andthen located inside a cylindrical module. The flow SPE experiments will be conducted and theprocess efficiency such as extraction recovery, concentration factor, process time, andpressure drop will be evaluated. The results will also be compared with the performance usingmembrane disc module to decide the optimal module design. Lastly, the whole processincluding the surfactant immobilization and hydrophobic SPE will be conducted in the flowmode using the best module design. In this way, a faster and more efficient solid-phaseextraction process could be developed.
URI: http://hdl.handle.net/11455/59085
其他識別: NSC97-2221-E005-041
文章連結: http://grbsearch.stpi.narl.org.tw/GRB/result.jsp?id=1684966&plan_no=NSC97-2221-E005-041&plan_year=97&projkey=PB9709-2472&target=plan&highStr=*&check=0&pnchDesc=%E5%9B%BA%E5%AE%9A%E9%9B%A2%E5%AD%90%E7%95%8C%E9%9D%A2%E6%B4%BB%E6%80%A7%E5%8A%91%E4%B9%8B%E9%9B%A2%E5%AD%90%E4%BA%A4%E6%8F%9B%E8%96%84%E8%86%9C%E7%B3%BB%E7%B5%B1%E7%95%8C%E9%9D%A2%E8%88%87%E8%B3%AA%E5%82%B3%E8%A1%8C%E7%82%BA%E4%B9%8B%E7%A0%94%E7%A9%B6
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