| 摘要: | 在氧氣與氮氣分離的技術中，薄膜分離是一種節能且相對便利的方法。混合基質薄膜(MMMs)透過將無機填料摻入高分子材料中，已經大量的被研究且證實能進一步的提升氣體分離能力。無機填料常見包含沸石、金屬氧化物、碳材料與金屬有機框架(MOFs)等。其中，金屬有機框架是一類由金屬離子與有機配體組成的多孔材料，具有高比表面積、可調孔徑與良好穩定性的特點，廣泛地被應用於氣體吸附、儲存與分離技術中。
本研究旨在開發可應用於如呼吸器等醫療用途的富氧混合基質薄膜。藉由利用氧氣(順磁性)與氮氣(逆磁性)之間不同的磁性性質，將合成的磁性金屬有機架構填料Fe3O4-UiO-66-NH2摻入到高分子聚碸(Polysulfone)中製備成薄膜，並在塗佈的過程中藉由外加的磁場來調控磁性填料於薄膜內部的空間排列行為，使之形成氣體傳輸通道，進而提升氣體分離效率。同時，因應近年來對於綠色製程的重視，在此研究中所使用之所有材料皆嚴格遵循環境安全規範，並確保不含歐盟高度關注物質(SVHC)清單中對人體健康或環境有害之成分。透過選用低毒性、可替代性高的原料或溶劑，使氣體分離薄膜能兼顧材料性能與永續性。在材料鑑定上，使用傅立葉轉換紅外光譜儀(FTIR)和X射線繞射儀(XRD)來確認填料的結構及其於高分子中的成功添加。透過掃描式電子顯微鏡(SEM)跟能量色散X射線光譜(EDS)可觀察到磁性填料在薄膜中受到磁場引導而產生方向性的排列結構，形成類似氣體傳輸通道的現象。動態光散射(DLS)分析填料粒徑分布，證實磁性填料的成功修飾並影響顆粒大小。熱重分析儀(TGA)則驗證填料與混合基質薄膜擁有高熱穩定性。氮氣吸脫附測試則顯示綠色溶劑合成之MOF具備明顯的微孔結構。最後，單一/混合氣體分離測試是使用商業化的氣體滲透率分析儀(GTR-11M)。單一氣體分離分析中，綜合效能最佳的混合基質薄膜比純Polysulfone薄膜在O2滲透率以及O2/N2選擇率分別增加102%與131%。然而混合氣體分離測試中，儘管維持相近的O2滲透率，O2/N2的選擇性則因氧氣與氮氣分子間的競爭吸附與擴散效應而大幅度的下降。
;Membrane separation is considered an energy-efficient and convenient method for O2/N2 gas separation. Mixed matrix membranes (MMMs), which incorporate inorganic fillers into polymer matrix, have been extensively studied and proven to significantly enhance gas separation performance. Common inorganic fillers include zeolites, metal oxides, carbon-based materials, and metal-organic frameworks (MOFs). Among these, MOFs are constructed from metal ions and organic linkers, which have advantages such as tunable pore sizes, high surface areas and excellent stability, making them ideal candidates for gas adsorption, storage, and separation.
This research aims to develop oxygen-enriched MMMs suitable for medical devices such as respirators. By utilizing the magnetic property differences between O2 (paramagnetic) and N2 (diamagnetic), magnetic MOF fillers Fe3O4-UiO-66-NH2 were synthesized and embedded into Polysufone to form membrane. During the casting process, an external magnetic field was applied to control the spatial alignment of magnetic fillers within the membrane, aiming to form gas transport pathways and enhance gas separation efficiency. Meanwhile, in alignment with the current trend toward eco-friendly manufacturing, all materials used in this study were selected to comply with environmental safety standards and were free of substances listed on the EU′s Substances of Very High Concern (SVHC) list. By using low-toxicity, sustainable solvents and materials, this study balances material performance with green chemistry principles.
Material characterization was conducted using FTIR and XRD to confirm the green synthesis of MOFs and their successful incorporation into the polymer matrix. SEM and EDS revealed the magnetic filler alignment under magnetic fields, forming channel-like structures. DLS confirmed particle size distribution changes after surface modification, and TGA verified the thermal stability of both fillers and membranes. Nitrogen adsorption–desorption (BET) tests further indicated that the green-synthesized MOFs retained distinct microporous characteristics and appropriate surface areas. Gas permeation properties were measured using a commercial gas permeation analyzer (GTR-11M). In single-gas testing, the best-performing MMM (10wt% A 3hr) showed a 102% increase in O2 permeability and a 131% increase in O2/N2 selectivity compared to the pristine PSF membrane. However, in mixed-gas (real air) separation tests, although the O2 permeability remained comparable, the O2/N2 selectivity dropped significantly due to competitive adsorption and diffusion effects between O2 and N2 molecules. |
