三醋酸纖維素薄膜構型對正向滲透效能之影響

Effect of the cellulose triacetate membrane morphology on the forward osmosis separation performance

尤文立(Felix Yu)

指導教授 ： 賴君義 ； 洪維松

中原大學/工學院/化學工程研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500734

摘要

本研究主為了針對正向滲透(FO)程序，利用結構控制設計出優於商業CTA正向滲透薄膜的高效能CTA正向滲透薄膜，研究係以濕式相轉化法製備出非對稱之薄膜，應用於正向滲透程序分離測試，且成膜機制利用動力學及熱力學來觀察探討，如霧點實驗、光穿透實驗、染色實驗。
研究中發現此系統雖然有巨型孔洞的生成，但由於整體結構皆屬封閉性的孔洞，造成正向滲透效能低下，藉由共溶劑的方式添加醋酸來調控結構，將原本封閉性的孔洞轉變成為連通性高的雙連續結構，但由於沒有緻密皮層而造成阻擋率下降，所以最後使用二胺單m-Phenylenediamine(MPD)以及醯氯單體1,3,5-Benzenetricarbonyl trichloride(TMC)，在改善連通性的CTA非對稱薄膜表面進行界面聚合反應，提供一高阻擋率。
由正向滲透的實驗結果顯示，封閉性孔洞的CTA非對稱基材薄膜，以PRO模式且在2.0M NaCl作為汲取液以及去離子水做為進料液的情況下，只有17.38LMH的水通量及17.72gMH的食鹽逆擴散量，而連通性的複合薄膜，可以提升至高達有46.62LMH水通量及5.45gMH的食鹽逆擴散量，說明了除了常提到影響效能因素有厚度、彎曲度及孔隙度，其孔洞的連通性也佔非常重要的一部分。

關鍵字

三醋酸纖維素 ； 正向滲透 ； 成膜機制

並列摘要

In this study, the CTA membrane structure was controlled to obtain higher-performance than the commercial CTA membrane for forward osmosis (FO) process. This study investigated CTA / dioxane / H2O and CTA / dioxane-acetic acid / H2O system by the wet-phase inversion method. The morphology variation were observed in membrane formation mechanism by cloud point, light transmission, optical microscopy experiments. Furthermore, we also investigated the effects of CTA membrane structure on the FO separation performance.
The experimental results show that the closed pores CTA asymmetric membrane water flux is 17.38LMH and salt reverse flux is 17.72gMH in PRO mode test with 2.0M NaCl as draw solution and deionized water solution as the feed solution, but when we add acetic acid to improve the connectivity of membrane pores, the water flux can be raised to up to have 46.62LMH and salt reverse flux is 5.45gMH , in fact pores connectivity accounted a very important part except the thickness, tortuosity and porosity of the often mentioned factors affect the FO performance.

並列關鍵字

cellulose triacetate ； forward osmosis ； membrane formation

參考文獻

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