Abstract Poor dispersity of filler particles always limits their application in mixed matrix membranes (MMMs), increasing the difficulties in membrane fabrication and restraining the full exploitation of the intrinsic separation ability of the fillers. Herein, polyethyleneimine (PEI), a functional branched polymer, was covalently bonded on the outer surface of CAU-1 nanoparticles to implement increased colloidal stability and improved CO2 affinity for MMMs preparation. As a result, the dispersity of CAU-1 particles in solvent and MMMs was greatly improved after surface functionalization. Meanwhile, the grafted PEI polymer chains can serve as CO2 carriers simultaneously, which benefits the CO2 transport in MMMs. The prepared MMMs based on modified CAU-1 exhibit largely improved CO2/CH4 separation performance, with a CO2 permeability of 546 Barrer and a CO2/CH4 separation factor of 27.8 at 30 wt% filler loading, showing 165% and 50% increases respectively compared with the pristine polymer membrane. The modification approach presented here is expected to extend the functionality of MOFs and facilitate the development of MMMs.

中文翻译：

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聚乙烯亚胺接枝改性提高胺官能化CAU-1基混合基质膜的颗粒分散性和CO 2 分离性能

摘要 填料颗粒分散性差一直限制了其在混合基质膜（MMMs）中的应用，增加了制膜难度，制约了填料固有分离能力的充分发挥。在此，聚乙烯亚胺 (PEI) 是一种功能性支化聚合物，共价键合在 CAU-1 纳米粒子的外表面上，以提高胶体稳定性并提高 MMM 制备的 CO2 亲和力。结果，CAU-1 颗粒在溶剂和 MMM 中的分散性在表面功能化后得到了极大的改善。同时，接枝的 PEI 聚合物链可以同时作为 CO2 载体，有利于 MMM 中的 CO2 传输。基于改性 CAU-1 制备的 MMMs 表现出大大提高的 CO2/CH4 分离性能，具有 546 Barrer 的 CO2 渗透率和 27.8 的 CO2/CH4 分离因子，在 30 wt% 填料负载下，与原始聚合物膜相比，分别显示 165% 和 50% 的增加。此处介绍的修改方法有望扩展 MOF 的功能并促进 MMM 的开发。