中/微孔洞之AlBTC有機-金屬氣凝膠/幾丁聚醣複合薄膜之製備及其於醇/水分離之應用

本研究利用熱處理之溶膠-凝膠法，結合金屬-有機配位物(Metal-organic framework, MOF)及氣凝膠(Aerogel)的概念，以MIL-100(Al)之單一粒子結構AlBTC為基礎，使其在溶劑中彼此縮合成大型網狀結構，製備出具有中/微孔洞之金屬-有機氣凝膠(Metal-organic aerogel, MOA)—AlBTC MOA，同時探討AlBTC溶膠溶液之濃度、以及反應溫度對AlBTC在成膠行為及膠體特性上的影響；其中不同溶膠濃度製備成的AlBTC MOA，以AlBTC-X (單位：mole/L) MOA為代號。本研究也同時將不同濃度的AlBTC MOA，混摻於幾丁聚醣(Chitosan, CS)高分子溶液內，形成有機-無機複合薄膜(Mixed matrix membranes, MMMs)，並應用於滲透蒸發程序。在25oC、90 wt%丁醇脫水效能測試中，添加0.3 wt%的AlBTC-0.075 MOA之AlBTC-0.075/CS複合膜，擁有本研究最佳通量1233 g/m2h、選擇比1574與PSI (Pervaporation separation index, PSI)為1941 Kg/m2h；若額外添加0.25 g的交聯劑，則使分離效能擁有更加優越的選擇性，其通量為526 g/m2h、選擇比4578和PSI值為2410 Kg/m2h。綜合上述各項結果，本研究針對操作溫度25oC、進料濃度為90 wt%的丁醇水溶液進行滲透蒸發分離，其中金屬-有機氣凝膠AlBTC的添加有助於提升有機高分子薄膜效能；而AlBTC結構中的有機配位體、及其與高分子鏈段間的氫鍵作用力，則有效增加有機-無機兩相的相容性、同時代替交聯劑固化高分子鏈段，藉以提升複合薄膜之選擇性。此外，相比於過去文獻分離丁醇之滲透蒸發效能，AlBTC MOA/CS MMMs在通量與選擇比都優越許多，表示AlBTC MOA及此類金屬-有機氣凝膠的孔洞材料，在滲透蒸發的應用層面上有卓越的潛力，能更有效地突破trade-off之限制、並且和高分子達成良好相容和分散的特性，進而同時提升通量及選擇比，於有機-無機複合薄膜之應用領域上有極佳的潛力。

關鍵字

滲透蒸發；有機-無機複合薄膜；有機-金屬氣凝膠；丁醇脫水

並列摘要

In this study, meso-/microporous AlBTC MOA (metal-organic aerogel) were synthesized via the sol-gel process. Its gelation mechanism was discussed by changing its reaction temperature and the concentration of AlBTC sol. Then as-synthesized particles were successfully incorporated into the chitosan polymeric solution to form mixed matrix membranes (MMMs) and used to dehydrate 90 wt% butanol/water mixture under 25oC in a pervaporation process. The as-prepared MMMs showed a good pervaporation performance on separating butanol/water. Because the meso-/microporous in AlBTC MOA provides more channels to permeate the feed, and the hydrophilicity of AlBTC MOA enhances the separation factor. However, when too much particles doped, the aggregation were occurred and formed unselective pores in the membrane, causing the pervaporation efficiency to reduce. As a result, we found the AlBTC/CS MMMs with 0.3 wt% AlBTC-0.075 doped had the best pervaporation performance. Its flux, separation factor, and pervaporation separation index (PSI) are 1233 g/m2h, 1574, 1941 Kg/m2h respectively. Moreover, when 0.25 g glutaraldehyde crosslinking is added AlBTC-0.075/CS MMMs obtains an even better performance. Its flux, separation factor, and PSI are 526 g/m2h, 4578, 2410 Kg/m2h respectively. Summarizing the above, the AlBTC/CS MMMs broke the trade-off between the flux and the separation factor, therefore, the MMMs has high flux and separation factor at the same time. In addition, the pervaporation performance of the AlBTC/CS MMMs in butanol dehydration clearly exceeds the upper limit of the membranes reported previously. It proves that the as-prepared AlBTC MOA and AlBTC/CS MMMs in this work, are promising materials in the pervaporation process. Key words: Pervaporation, Mixed Matrix Membranes, Metal-Organic Aerogel, alochol dehydration

並列關鍵字

Pervaporation ； Mixed Matrix Membranes ； Metal-Organic Aerogel ； alochol dehydration

參考文獻

[1] R.W. Baker, Membrane technology and applications, second edition, John Wiley & Sons Ltd (2004).

[2] W.W, Basic principles of membrane, second edition, Kluwer Academic Publishers (1997).

[3] V.V. Namboodiri and L.M. Vane, High permeability membranes for the dehydration of low water content ethanol by pervaporation, J. Membr. Sci. 306 (2007) 209–215.

[4] B. Smitha, D. Suhanya, S. Sridhar and M. Ramakrishna, Separation of organic–organic mixtures by pervaporation-a review, J. Membr. Sci. 241 (2004) 1–21.

[5] J.G. Wijmans and R.W. Baker, The solution-diffusion model: a review, J. Membr. Sci. 107 (1995) 1–21.

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中/微孔洞之AlBTC有機-金屬氣凝膠/幾丁聚醣複合薄膜之製備及其於醇/水分離之應用

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