Abstract:

Mixed matrix membranes (MMMs) have promising applications in the field of gas separation, and metal-organic frameworks (MOFs) are often used as fillers to prepare MMMs due to their high porosity and organic linking groups. However, the improvement of gas separation performance of MMMs is limited due to the interfacial compatibility between MOFs and polymers. Herein, a functionalized Zr-MOF (UiO-66-AC) was synthesized to prepare mixed matrix membranes with poly(ether-b-amide) (Pebax). The introduction of groups such as carbonyl and carboxyl groups in the filler provided strong interfacial interactions between MOFs and the polymer matrix. Compared with pristine Pebax membranes, the gas permeability of UiO-66-AC/Pebax MMMs was significantly improved. When the filler content was 6%, the CO₂ permeability coefficient of the membrane was 102.4 Barrer, the CO₂/N₂ and CO₂/CH₄ selectivities were 90.6 and 26.0, respectively, and the CO₂/N₂ separation performance exceeded the Robeson upper bond (2008), indicating that the UiO-66-AC/Pebax MMMs had potential for CO₂ separation applications.

Key words: metal organic framework, mixed matrix membranes, CO₂ capture, Pebax

摘要：

混合基质膜（MMMs）在气体分离领域具有良好的应用前景，金属有机框架（MOFs）由于具有高孔隙率和有机连接基团，常被用作填料制备MMMs。但由于MOFs与聚合物的界面相容性问题，MMMs的气体分离性能提升受到限制。本文合成了功能化的Zr-MOF（UiO-66-AC），并利用其与聚醚共聚酰胺（Pebax）共同制备了混合基质膜。填料中引入的羰基和羧基等基团提供了MOFs与聚合物基质之间较强的界面相互作用。与纯Pebax膜相比，UiO-66-AC/Pebax MMMs的气体渗透性能得到了显著提高。当填料质量分数为6%时，膜的CO₂渗透系数为102.4 Barrer，CO₂/N₂和CO₂/CH₄选择性分别为90.6和26.0，CO₂/N₂分离性能突破了Robeson上限(2008)，表明该混合基质膜在CO₂的分离应用上具有潜力。

关键词: 金属有机框架, 混合基质膜, CO₂捕集, 聚醚共聚酰胺