聚電解質錯合物薄膜用於滲透蒸發分離之研究

本研究使用陰離子型聚電解質Sodium Carboxymethyl Cellulose (CMCNa)與四種不同的陽離子型聚電解質Polyethylenimine Linear(lPEI), Polyethylenimine branched(bPEI),poly(dimethyl aminoethyl methacrylate methyl chloride)(PDMC),Poly(diallyldimethylammonium chloride) (PDDA)利用酸保護去保護的方式，製備聚電解質錯合物，並將所製備出之聚電解質錯合物配製成鑄膜液利用塗佈法刮製於Cellulose acetate (CA)上再藉由乾式法成膜，製備一聚電解質錯合物複合薄膜(PEC/CA thin-film composite membrane)。研究以不同的基材以及使用不同陽離子型聚電解質製備錯合物，以及對於薄膜之滲透蒸發之影響，並改變聚電解質錯合物之錯合度對於薄膜之親疏水性以及滲透蒸發之影響。利用全反射式傅立葉轉換紅外線光譜儀(ATR-FTIR)與X射線光電子能譜儀(XPS)鑑定聚電解質的化學結構及組成，對水接觸角(CA)鑑定聚電解質錯合物之親疏水性，並使用掃描式電子顯微鏡(SEM)與原子力顯微鏡(AFM)分析表面及截面型態與粗糙度。實驗結果發現，改變不同的基材製備出之薄膜以製備於CA基材上之薄膜具有最高的透過量，由於CA基材所具有的質傳阻力最低；當改變不同陽離子聚電解質製備聚電解質錯合物薄膜時，由於不同聚電解質所具有的立體空間障礙不同，以及所能錯合的數量不同，因此會影響聚電解質錯合物之透過量以及選擇性。實驗結果顯示，當使用CA做為薄膜之基材，以CMCNa-bPEI錯合物於保護程度90%時，在此情況下所製備的聚電解質錯合物薄膜(CMCNa-bPEI90/CA)，應用於滲透蒸發程序分離90wt%乙醇水溶液，具有最佳的分離效能，其透過量大於800g/m2h，而出口端水濃度大於99wt% 。在此也探討滲透蒸發操作條件變化，其中包含進料溫度、濃度、不同碳數醇類溶液及真空度高低，對於滲透蒸發分離效能的影響，實驗結果發現此薄膜在大部分條件下均可維持良好的分離效能。

關鍵字

滲透蒸發；聚乙烯亞胺；薄膜；聚電解質錯合物；乙醇脫水

並列摘要

The polyelectrolyte complex were prepared by protection- deprotection method, in this research we used anion polyelectrolyte Sodium Carboxymethyl Cellulose (CMCNa) complexed with four different types of cation polyelectrolytes, polyethylenimine Linear (lPEI), polyethylenimine branched (bPEI),poly (dimethylaminoethyl methacrylate methyl chloride)(PDMC),poly (diallyldimethylammonium chloride) (PDDA),by blending two different types polyelectrolytes to get our solid forms polyelectrolyte complex and dissolved in NaOH .when polyelectrolyte complex fully dissolved in solve homogenous, casting onto asymmetric Cellulose acetate (CA) substrate. These polyelectrolyte complex membranes were applied in the pervaporation of separating aqueous ethanol solution. polyelectrolyte complex casting onto different substrate in order to correlate with pervaporation performance. we also prepare different kind polyelectrolyte complexs and changed the polyelectrolyte complex degrees. Effect of substrate ,types of polyelectrolyte complex and ion complex degrees on pervaporation performance are discussed. Attenuated total reflection infrared spectroscopy (ATR-FTIR) and x-ray photoelectron spectroscopy (XPS) were used to characterize the chemical structures and composition of element of the ultra-thin active layers. The pervaporation performance of substrate membrane and polyelectrolyte complex membrane were characterized by contact angle. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the surface and cross-sectional morphologies of the polyelectrolyte complex membranes. From the results of the pervaporation separation experiments, the most desirable conditions for the polyelectrolyte complex membrane are as follows: the polyelectrolyte complex were prepared by CMCNa and bPEI, cast on to CA substrate, and protected 90% polyelectrolyte complex .The resulting membrane is obtained and has the best pervaporation performance of a 90 wt% aqueous ethanol solution, which is a permeation flux of above 800 g/m2h and a water concentration in permeate higher than 99 wt%. The operating conditions of pervaporation process, such as operating temperature, feed concentration, permeate pressure, feed component, were also investigated.

並列關鍵字

Polyethylenimine ； Polyelectrolyte complex ； Membrane ； Pervaporation ； Ethanol dehydration

參考文獻

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國際替代計量

聚電解質錯合物薄膜用於滲透蒸發分離之研究

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