延遲定型與紡絲條件對非對稱聚嗍碸中空纖維膜滲透蒸發分離效能之影響

Effect of Delay Demixing and Spinning Condition on the Morphology and Separation Performance of Asymmetric Hollow Fiber Polysulfone Membrane

本研究利用延遲定型方式於聚嗍碸紡絲液中加入非親水性溶劑（氯仿）形成共溶劑系統，利用紡絲條件（濕式紡絲及乾/濕式紡絲）變化增進延遲定型效果，製備出所需之中空纖維膜結構，研究中探討中空纖維膜結構型態對滲透蒸發分離乙醇/水溶液效能之影響。研究結果發現Polysulfone/N-methyl-pyrrolidone（PSF/NMP）紡絲系統中添加入氯仿，以濕式紡絲法成膜並以去離子水作為凝聚劑時，中空纖維膜因氯仿添加而延遲定型，使纖維膜中之巨型孔洞因溶劑添加而抑制，但其皮層緻密程度不足，因而促進滲透蒸發分離之選擇性上升不明顯，而當以乾/濕式並添加氯仿為共溶劑，於維持氣距（Air gap）條件下，促使外皮層高分子濃度有效增加形成高分子富相，中空纖維進入凝聚劑（去離子水）進行（溶劑/凝聚劑）相轉換時因延遲定型時，顯著增進外皮層之緻密性與連續性，中空纖維膜具有緻密性外皮層與孔隙性內皮層構造，由於外皮層巨孔明顯變小形成海綿性結構有利於選擇性提升，本研究有效利用延遲定型與紡絲條件可以製備出緻密之外皮層結構並有效提升滲透蒸發效能。

The delay demixing behavior can be improved by hydrophobic solvent （chloroform） additive and suitable spinning conditions. The effects of membrane structure on separation performance of pervaporation membranes were investigated. The suitable morphology can be prepared by appreciate chloroform addition in the casting. It was found that the insufficient delay demixing behavior were caused by the chloroform in the case of wet phase inversion system and it is also found that the skin layer did not well formation during the phase inversion of casting solution and resulted a low selective membranes. The good skin layer formation is contributed by the effective increase in polymer rich phase during the membrane formation. With increasing the polymer concentration in the skin layer, the defects free and continuous polymer phase can be formed in the coagulant bath during the membrane formation. The skin layer and porous sublayer of asymmetric membrane were prepared with continuous changed the spinning conditions. It was found that the skin layer and suitable separation performance asymmetric polysulfone membrane can be prepared by using the delay demixing method and suitable spinning conditions in the membrane formation.