原位界面聚合法製備聚醯胺複合中空纖維膜應用於滲透蒸發分離程序之研究

Preparation of polyamide/PAN composite hollow fiber membranes for pervaporation by in situ interfacial polymerization

陳雅菱(Ya-Ling Chen)

中原大學/工學院/化學工程研究所/碩士(2012年)

https://doi.org/10.6840/cycu201200614

摘要

本研究首創原位界面聚合法製備聚醯胺(Polyamide, PA)/聚丙烯晴(Polyacrylonitrile, PAN)複合中空纖維膜應用於滲透蒸發分離程序，成功地在製備PAN基材膜的同時，於中空纖維內表面進行界面聚合，製備一層PA選擇層。為改善PA選擇層與基材之貼合性，本研究添加親水性之二氧化矽奈米顆粒於PAN鑄膜液中以增加親水性及對水相單體的吸附性，使PA薄膜與PAN基材間展現優異的貼合性。
研究中探討水相單體tetraethylenepentamine (TEPA)濃度以及流速對於薄膜結構以及滲透蒸發效能之影響，並經由FTIR、SEM、AFM以及PAS進行中空纖維膜內表面之檢測。結果發現當增加水相單體濃度時，聚合反應機會增加，會形成更緻密且厚之PA選擇層。由S參數與R參數也證實當胺單體濃度增加到14 wt.%時確實有最小的S值與R值，並且由正子檢測也可觀察到其具有最厚且最緻密的選擇層，因此於滲透蒸發操作程序分離90wt.%異丙醇水溶液時可以有效提升透過端水濃度。而隨著水相單體流速增加，透過量增加但透過端水濃度下降，當TEPA濃度為14wt.%、流速為1ml/min時有一最佳之滲透蒸發效能；在25℃下，針對90wt.%之異丙醇水溶液進行分離可獲得透過量為419g/m2 h、透過端水濃度為96.6wt.%之滲透蒸發分離效能。
在滲透蒸發分離操作程序方面，探討不同的進料濃度與進料物種對於滲透蒸發效能之影響。隨著異丙醇進料濃度增加，透過量會下降而透過端水濃度會上升；當進料醇類之碳數增加(甲醇、乙醇、異丙醇及第三丁醇)，其透過量有先下降後持平之現象而透過端水濃度則是隨之上升，本研究製備之PA/PAN複合中空纖維膜針對異丙醇與第三丁醇可展現出優異之分離效能，其透過端水濃度分別可達96.6wt%與99.0wt%。

關鍵字

中空纖維膜 ； 界面聚合 ； 滲透蒸發

並列摘要

In this study, the polyamide (PA)/Polyacrylonitrile (PAN) composite hollow fiber membranes were prepared successfully via in situ interfacial polymerization of tetraethylenepentamine (TEPA) and trimesoyl chloride (TMC) onto the inner surface of PAN hollow fiber membranes for pervaporation dehydration of water/alcohol mixtures. To improve the compatibility between the polyamide layer and the PAN substrate, silica nanoparticles were added into the PAN dope to enhance the hydrophilicity of dope solution and increase the sorption of amine aqueous solution.
The effect of TEPA concentration and the flow rate of aqueous solution on membrane morphology and pervaporation performance of 90wt.% aqueous isopropanol solution were investigated. The permeation rate decreased while water concentration in permeate increased with increasing the TEPA concentration resulted in the increase of polyamide thickness and packing density. These results were confirmed by the PAS analysis. The PAS analysis revealed that S parameter and R parameter decreased with increasing TEPA concentration. Furthermore, the permeation rate also increased while water concentration in permeate decreased with increasing the flow rate of amine aqueous solution. A 419g/m2h of permeation rate and 96.6wt.% of water concentration in permeate could be gotten through the 14wt.% of TEPA concentration and 1ml/min flow rate of amine aqueous solution fabricated PA/PAN composite hollow fiber membranes for pervaporation 90wt.% aqueous isopropanol solution at 25 C.
Moreover, the effect of pervaporation condition such as: feed concentration and carbon number of feed alcohol (methanol, ethanol, isopropanol and tert-butanol) on the pervaporation performances were also investigated. The permeate rate increased and water concentration in permeate decreased with decreasing isopropanol concentration. As increasing the carbon number of feed alcohol, the permeation rate decreased first then level off and the water concentration in permeate increased. The PA/PAN hollow fiber membranes exhibited high pervaporaiton performance, especially for isopropanol and tert-butanol mixtures. The water concentration in permeate were 96.6wt.% and 99.0wt.% for separating 90wt.% isopropanol and tert-butanol aqueous solution, respectively.

並列關鍵字

hollow fiber membrane ； interfacial polymerization ； pervaporation

參考文獻

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