聚環氧乙烷/重組蜘蛛絲共混薄膜於二氧化碳分離之應用

Abstract

因應氣候變遷與碳排放問題，發展高效率且具選擇性的CO₂分離技術已成為綠色化工與能源領域的重要課題。有機高分子薄膜因具備能耗低、模組化程度高等優勢，是目前最具潛力的CO₂捕捉方式之一。然而，高分子薄膜材料普遍面臨滲透率與選擇性難以兼顧的瓶頸，限制其實際應用。本研究提出聚環氧乙烷 (PEO)與重組蜘蛛絲蛋白 (R2)之共混策略，藉由R2改善PEO的機械性質並降低其結晶度，同時保留PEO對CO₂的親和性，以開發兼具氣體分離性能與機械強度之高分子薄膜。實驗結果顯示，當R2含量為20 wt%時，薄膜之伸長率與韌性分別提升至1001%與180.9 MPa，結晶度則由76%降至58%；其氣體分離表現亦大幅改善，CO₂滲透率由22.6 Barrer提高至109.5 Barrer，CO₂/N₂選擇性由45升至64。此性能提升源於非晶區比例增加，以及R2中胺基或醯胺基對CO₂分子的選擇性吸附作用，進一步提供更多CO₂滲透通道與吸附位點。綜上所述，PEO/R2共混薄膜在機械強度與氣體分離效率間取得良好平衡，展現作為環境友善型CO₂分離薄膜材料之應用潛力。

In response to climate change and carbon emissions, the development of highly efficient and selective CO₂ separation technologies has become a critical issue in the fields of green chemistry and energy. Among various approaches, polymeric membranes are considered one of the most promising solutions for CO₂ capture due to their low energy consumption and high modularity. However, conventional polymer membranes often face a trade-off between permeability and selectivity, which limits their practical application. This study proposes a blending strategy using poly(ethylene oxide) (PEO) and recombinant spider silk protein (R2), aiming to enhance the mechanical properties of PEO and reduce its crystallinity while retaining its strong affinity for CO₂. Experimental results demonstrate that when the R2 content reaches 20 wt%, the resulting membrane exhibits a significant improvement in mechanical performance, with an elongation at break of 1001% and a toughness of 180.9 MPa, while the crystallinity decreases from 76% to 58%. Moreover, the gas separation performance is markedly enhanced, with CO₂ permeability increasing from 22.6 to 109.5 Barrer and CO₂/N₂ selectivity rising from 45 to 64. These improvements are attributed to the increased proportion of amorphous regions and the selective affinity of amino and amide groups in R2 for CO₂ molecules, which provide additional permeation channels and adsorption sites. In conclusion, the PEO/R2 blend membranes achieve a desirable balance between mechanical strength and gas separation efficiency, demonstrating strong potential as an environmentally friendly material for CO₂ separation applications.