水氣誘導式相分離對聚碸中空纖維膜成膜機制之研究

Investigation of vapor induced phase separation on membrane formation mechanism of polysulfone hollow fiber membrane

林俊豪(Jiun-Hao Lin)

指導教授 ： 賴君義

中原大學/工學院/化學工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500308

摘要

中文摘要
本研究係以Polysulfone (PSf)/N-methyl-2-pyrrolidinone (NMP)為鑄膜液，利用乾濕式紡絲法(dry/wet spinning)製備PSf中空纖維膜(hollow fiber membrane)，探討水氣誘導式相分離(Vapor induced phase separation, VIPS)對PSf 中空纖維膜的結構型態影響及其成膜機制。研究結果發現，當以水為凝聚劑時，在不同溼度下皆有隨著氣距長度增加，中空纖維膜截面巨型孔洞會有被抑制、再生成、再被抑制的現象；在外皮層附近微結構變化方面，則隨著氣距增加，會由緻密結構變成蕾絲狀結構，再合併成海綿狀結構。若以液態氮為凝聚劑固定中空纖維膜在空氣中受水氣影響結構變化，則發現隨著氣距增加，巨觀下中空纖維膜外層未有巨型孔洞生成，而外皮層附近結構會由微相分離結構變成蕾絲狀結構，再合併成海綿狀結構。顯示在空氣中中空纖維膜吸收水氣會生成微相分離結構或蕾絲狀結構，浸入凝聚槽（水）後，結構會受水影響而成長為蕾絲狀結構或海綿狀結構。研究中亦改變不同紡絲線速度探討其水氣誘導式相分離紡製中空纖維膜成膜機制之影響。結果發現紡絲線速度增加，會促使水氣與NMP交換速度增加，而導致系統較快發生相分離。

關鍵字

聚碸 ； 中空纖維膜 ； 巨型孔洞 ； 水氣誘導相分離 ； 氣距

並列摘要

Abstract
In this study, the effect of vapor induced phase separation (VIPS) on the morphology and formation mechanism of Polysulfone (PSf) hollow fiber membranes were investigated. PSf hollow fiber membranes were fabricated via dry/wet spinning process with different air gap under various relative humidity. N-methyl pyrrolidinone (NMP) was used as the solvent. The results show that by introducing the dry/wet spun PSf hollow fiber membranes into water bath, the macrovoids morphology of hollow fiber membrane can be suppressed, recreated, and resuppressed as increasing the air gap regardless of relative humidity. The macrovoids suppressed, recreated, as well as resuppressed air gap decreased with increasing the relative humidity. The results also show that the microstructure of PSf hollow fiber membranes can formed from dense to lacy structure and coarsened to form sponge-like structure as increasing the air gap. By introducing the as-spun hollow fiber membranes into liquid nitrogen directly after went through air gap zone, micro phase separation structure, lacy structure, and sponge-like structure can be found as increasing the air gap. These results can tell us that the micro phase separation structure and lacy structure induced by water vapor during air gap zone can further grow to form lacy and sponge structure by introducing the nascent hollow fiber membranes into water bath. Moreover, the effect of spinning speed on the formation mechanism of PSf hollow fiber membranes spun via VIPS was also investigated. The data show that by increasing the spinning speed, the exchange rate of water vapor and solvent was increased and induced the phase separation.

並列關鍵字

macrovoids ； vapor induced phase separation ； hollow fiber membrane ； Polysulfone

參考文獻

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