幾丁聚醣混成膜中無機材成份對滲透蒸發效能之影響

Effect of inorganic component of chitosan hybrid membrane on the pervaporation performance

蘇郁蕙(Yu-Huei Su)

指導教授 ： 賴君義

中原大學/工學院/化學工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400527

摘要

本研究利用兩種不同的無機物添加於幾丁聚醣中，製備出有機/無機混成薄膜，探討混成程序及無機添加物的含量對幾丁聚醣物性之影響，並探討混成薄膜應用在滲透蒸發分離高濃度異丙醇水溶液之分離效能及其長期穩定性的影響。
影響有機/無機混成材料性質主要是有機相與無機相的分散狀態，在本研究所使用的兩種無機添加物其與幾丁聚醣之反應機制不同，分為兩個部分加以探討。第一部份為利用溶液插層法製備出幾丁聚醣/蒙脫土混成薄膜，由廣角X-ray繞射實驗(WXRD)及穿透式電子顯微鏡(TEM)中發現，添加少量的蒙脫土於幾丁聚醣中，蒙脫土於有機相中之狀態屬於奈米級結構，且其機械性質及熱穩定性皆有所提升。此外將該混成薄膜應用於滲透蒸發分離異丙醇水溶液，探討蒙脫土的添加量、進料濃度對其分離性能的影響外，發現在分離90 wt%異丙醇水溶液時，所製備出的幾丁聚醣/蒙脫土混成薄膜其薄膜厚度愈小，透過量愈大，選擇性則不受影響，例如：薄膜厚度約8.5 μm時，其透過量為640 g/m2 h，透過水濃度大於99 wt%，且其長期滲透蒸發穩定性測試，發現經453 天分離效能大致維持不變。
第二部份乃利用溶膠-凝膠法製備出幾丁聚醣/氧化矽薄膜，由固態的核磁共振儀(Solid State-NMR)、全反射式傅立葉轉換紅外線光譜儀(ATR-FTIR)證明幾丁聚醣之胺基確實與所添加含矽的交聯劑（GPTMS）的環氧基產生交聯反應，藉由掃瞄式電子顯微鏡-能量散射光譜儀(SEM-EDS)及TEM分析發現，添加少量的GPTMS時，有機相與無機相會形成相互交錯的結構，若添加大量的GPTMS時，則無機相的氧化矽容易聚集成三維的氧化矽粒子，同時所製備出的膜材會變脆，而不利於滲透蒸發操作。此外，研究中進一步探討幾丁聚醣/氧化矽薄膜中，GPTMS的添加量對滲透蒸發分離70 wt%異丙醇水溶液分離效能，及其長期穩定性的影響，發現所製備出的混成薄膜組成其透過量約為1700 g/m2 h，透過水濃度大於98 wt%，且其分離效能之穩定性可維持141天以上。

關鍵字

幾丁聚醣 ； 有機無機混成 ； 薄膜 ； 滲透蒸發

並列摘要

In this study, two kinds of organic/inorganic hybrid membrane was prepared by adding montmorillonite (MMT) clay or 3-glycidoxypropyl -trimethoxysilane (GPTMS) in the chitosan solution. The effects of the condition of hybrid procedure and inorganic material content on the pervaporation performance and long-term stability of the hybrid membrane for the separation of aqueous isopropanol solution were investigated.
The improvement of the mechanical and pervaporation properties of the organic/inorganic hybrid membranes are presumably due to the effect of nanoscale structure and the interaction between polymer and inorganic material. This study was divided into two parts according to starting materials and processing techniques. For the first part, chitosan/clay hybrid membranes were prepared by dispersing the nanolayers of inorganic montmorillonite (MMT) clay into organic chitosan matrix via the solution intercalation. The prepared hybrid membranes were characterized by using wide-angle X-ray diffraction (WXRD), transmission electron microscopy (TEM). Compared with pure chitosan membrane, the chitosan/clay hybrid membrane effectively improve the mechanical properties and thermal stability. In addition, the effects of the feed isopropanol concentration and the compositions of the chitosan/clay hybrid membranes on the pervaporation performances were also investigated. It was observed that the flux increased and the water concentration in permeate was not evidently affected with decreasing. the chitosan/clay hybrid membranes thickness. As the thickness of chitosan/ clay hybrid membranes was 8.5 μm, a flux of 640 g/m2 h, and water concentration in permeate higher than 99 wt% obtained with a 90 wt% aqueous isopropanol solution. Till now, the membrane life through the durability test for 90 wt% aqueous isopropanol solution has more than 453 days.
For the second part, chitosan/silica membranes were prepared by sol-gel method. In order to confirm the crosslinking reaction between chitosan and crosslinking agent containing siloxane (GPTMS), solid state-nuclear magnetic resonance spectrometer (Solid state-NMR), and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to characterize the hybrid membranes. While with 50 wt% GPTMS in chitosan matrix, we found that the silica network spreads out like a hyper-branched cluster by using scanning electron microscopy-energy dispersive spectrometer (SEM-EDS) and transmission electron microscopy (TEM). In addition, the effects of the compositions of chitosan/silica membranes on the pervaporation separation performances of 70 wt% aqueous isopropanol solution was investigated. The chitosan/silica membranes effectively improve the pervaporation performance and the long-term stability for the separation of aqueous isopropanol solution.
誌謝

並列關鍵字

pervaporation ； membrane ； organic-inorganic hybrid ； chitosan

參考文獻

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