官能化氧化石墨烯/聚醯亞胺複合薄膜製備與滲透蒸發分離之研究

Study on the preparation and pervaporation separation of functionalized graphene oxide/Matrimid composite membrane

詹靜芸(Jin-Yun Zhan)

指導教授 ： 李魁然 ； 蔡惠安

中原大學/工學院/化學工程研究所/碩士(2020年)

https://doi.org/10.6840/cycu202000273

摘要

本研究將具旋轉結構之改質氧化石墨烯(GO)混摻入聚醯亞胺Matrimid®高分子溶液中，以旋轉塗佈技術將Matrimid®高分子溶液塗佈於PSf基材膜上，製備成Matrimid®/PSf複合薄膜，並應用於滲透蒸發操作程序分離異丙醇水溶液。因Matrimid®溶液含有NMP溶劑，於旋轉塗佈程序中可微溶PSf基材，因此Matrimid®與PSf基材兩者之間無產生介面缺陷。於本研究中，同時探討Matrimid®溶液旋轉塗佈之層數及轉速對所製備之Matrimid®/PSf複合薄膜滲透蒸發效能之影響。
研究中GO分別經過BPA、PIMOH及PIMDA接枝改質，並混摻入Matrimid®高分子溶液中，探討薄膜之物化性與異丙醇水溶液分離效能之滲透蒸發效能。由FTIR鑑定發現，單體皆成功接枝於GO表面上；透過XRD分析可發現，改質後GO粉末之層間距皆變大，因此當混摻入Matrimid®時， DBES顯示改質GO添加後，薄膜可創造出較大之自由體積，使得薄膜滲透蒸發透過通量上升，而GO之片狀結構也提升薄膜之選擇性。PIMDA因具有最大之單體體積以及單體中帶有旋轉結構，因此以PIMDA改質的GO (PIMDAGO)製備之Matrimid®/PSf複合薄膜具有最大之自由體積，有利於薄膜之滲透蒸發透過量提升。
當添加0.5 wt%之PIMDAGO於Matrimid®溶液中，以4,500 rpm之轉速進行2次旋轉塗佈所製備之Matrimid®/PSf複合薄膜(M_PIMDA0.5)，具有最佳之滲透蒸發效能。在25OC，70 wt%異丙醇水溶液中其透過量為915 gm-2h-1，透過端水濃度為99.07 wt%。同時，該薄膜在經過168小時後之滲透蒸發效能測試，依然維持良好之透過量及選擇性。

關鍵字

氧化石墨烯 ； 聚醯亞胺 ； 複合薄膜 ； 滲透蒸發

並列摘要

Isopropanol is an important solvent used to production of various chemical reagents such as cosmetics, household chemical and repellents. For industrial application, the solvent must usually be anhydrous. Finding new potential materials for pervaporation membrane is still an interest to overcome these problems.
The novelty of this study was incorporating modified graphene oxide (GO) which was functionalized by spirobisindane diamine and diol (BPA; PIMDA; PIMOH;) monomer for fabricating the Matrimid® selective layer by spin-coating process. With the aid of Matrimid®/NMP slightly dissolved in PSf support which enhanced the compatibility between the two materials. The resultant modified GO did not only possess covalent bond but also displayed adjustable microstructure properties as confirmed by XPS, FTIR, XRD and positron annihilation spectroscopy (PAS).
Membranes incorporated with PIMDA has the highest flux due to its hierarchical and bulky structure which created larger free volume. Due to the laminate structure of GO, it provided tortuous pathway which increased the selectivity. All membrane with modified graphene oxide exhibited a better permselectivity than pristine graphene oxide membranes. Among all the membrane, M¬_PIMDA0.5 has the best pervaporation performance with a total flux of 915 gm-2h-1 and water permeate concentration of 99.07 wt% at 25OC for 70 wt% IPA dehydration. The membrane was also tested for the dehydration of methanol, ethanol and n-butanol. After 168 hours of pervaporation test, the membrane maintained the flux and selectivity which showed good stability.

並列關鍵字

Graphene oxide ； Polyimide ； Composite membrane ； Pervaporation

參考文獻

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