Muthukumaraswamy Rangaraj Vengatesan, Wahab Mohammad A, Reddy K Suresh Kumar, Kakosimos George, Abdalla Omnya, Favvas Evangelos P, Reinalda Donald, Geuzebroek Frank, Abdala Ahmed, Karanikolos Georgios N
Department of Chemical Engineering, Khalifa University, Abu Dhabi, United Arab Emirates.
Chemical Engineering Program, Texas A&M University at Qatar, Doha, Qatar.
Front Chem. 2020 Jul 3;8:534. doi: 10.3389/fchem.2020.00534. eCollection 2020.
Gas separation and purification using polymeric membranes is a promising technology that constitutes an energy-efficient and eco-friendly process for large scale integration. However, pristine polymeric membranes typically suffer from the trade-off between permeability and selectivity represented by the Robeson's upper bound. Mixed matrix membranes (MMMs) synthesized by the addition of porous nano-fillers into polymer matrices, can enable a simultaneous increase in selectivity and permeability. Among the various porous fillers, metal-organic frameworks (MOFs) are recognized in recent days as a promising filler material for the fabrication of MMMs. In this article, we review representative examples of MMMs prepared by dispersion of MOFs into polymer matrices or by deposition on the surface of polymeric membranes. Addition of MOFs into other continuous phases, such as ionic liquids, are also included. CO separation from hydrocarbons, H, N, and the like is emphasized. Hybrid fillers based on composites of MOFs with other nanomaterials, e.g., of MOF/GO, MOF/CNTs, and functionalized MOFs, are also presented and discussed. Synergetic effects and the result of interactions between filler/matrix and filler/filler are reviewed, and the impact of filler and matrix types and compositions, filler loading, surface area, porosity, pore sizes, and surface functionalities on tuning permeability are discoursed. Finally, selectivity, thermal, chemical, and mechanical stability of the resulting MMMs are analyzed. The review concludes with a perspective of up-scaling of such systems for CO separation, including an overview of the most promising MMM systems.
使用聚合物膜进行气体分离和纯化是一项很有前景的技术，它构成了一种用于大规模集成的节能且环保的工艺。然而，原始的聚合物膜通常存在由罗布森上限所表示的渗透率和选择性之间的权衡。通过将多孔纳米填料添加到聚合物基质中合成的混合基质膜（MMM），可以同时提高选择性和渗透率。在各种多孔填料中，金属有机框架（MOF）近年来被认为是用于制造MMM的一种有前景的填料材料。在本文中，我们回顾了通过将MOF分散到聚合物基质中或沉积在聚合物膜表面制备的MMM的代表性实例。还包括将MOF添加到其他连续相中，如离子液体中。重点介绍了从碳氢化合物、氢气、氮气等中分离一氧化碳的情况。还介绍并讨论了基于MOF与其他纳米材料（如MOF/氧化石墨烯、MOF/碳纳米管和功能化MOF）复合材料的混合填料。综述了填料/基质和填料/填料之间的协同效应及相互作用结果，并论述了填料和基质类型与组成、填料负载量、表面积、孔隙率、孔径和表面官能团对调节渗透率的影响。最后，分析了所得MMM的选择性、热稳定性、化学稳定性和机械稳定性。综述最后展望了此类用于一氧化碳分离系统的放大应用，包括对最有前景的MMM系统的概述。
