Abstract:

Membrane technology for carbon dioxide capture and separation with advantages of high efficiency, energy saving and economic becomes the current hot research topic. Polymer membranes have been widely commercialized because of their high processability and low cost, but they have the problem of "trade-off" effect of permeability and selectivity, that is, highly permeable membranes have low selectivity, and vice versa. The mixed matrix membrane prepared by adding porous materials to polymer matrix can improve the gas permeability and selectivity at the same time, which has become a research trend in the field of gas separation membrane. In this paper, the research progress on the stability of mixed matrix membranes prepared by polyether block polyamide (Pebax) as polymer matrix and porous materials as fillers was reviewed. The chemical stability of zeolite, metal-organic frameworks and covalent organic frameworks in the presence of water, acid, alkali and organic solvent was summarized and their mechanisms were explained. This paper focused on the current status of the research on the moisture resistance and long-term stability of Pebax mixed matrix membranes during CO₂ separation. Finally, aiming at the development of membrane stability in the field of gas separation, research focuses were put forward on the porous materials and membrane in basic research, and the research directions for theory of cross experiment and diversified means to evaluate membrane stability were pointed out. In addition, strategies to improve membrane stability were proposed from the design and preparation of fillers and polymers, aiming to further improve the separation stability of Pebax mixed matrix membrane for CO₂ mixed gas.

Key words: CO₂ separation, porous materials, polyether block polyamide (Pebax), mixed matrix membranes, stability

摘要：

膜技术在二氧化碳捕集和分离过程中以高效、节能、经济等优势成为当前研究的热潮。聚合物膜由于可加工性强、成本低廉等优点已被广泛商业化，但聚合物膜存在渗透性和选择性的“trade-off”效应问题，即高渗透性膜选择性反而低，反之亦然。将多孔材料加入聚合物基质中制备的混合基质膜能够实现气体渗透性和选择性的同时提升，成为气体分离膜领域的研究趋势。本文综述了聚醚嵌段聚酰胺（Pebax）为聚合物基质、多孔材料为填料所制备的混合基质膜在二氧化碳分离稳定性方面的研究进展。概述了沸石、金属有机骨架和共价有机骨架三类多孔材料在水、酸、碱和有机溶剂等存在下的化学稳定性并对其机理进行解释。重点介绍了以Pebax为基质的混合基质膜在CO₂分离过程中抗湿性和长期稳定性的研究现状。最后，针对膜稳定性在气体分离领域的发展，提出了多孔材料和膜在基础研究中的研究重点，指出了理论交叉实验以及多样化手段评估膜稳定性的研究方向。此外，从填料和聚合物的设计制备角度提出了改善膜稳定性的策略，旨在进一步提升Pebax混合基质膜对CO₂混合气体的分离稳定性。

关键词: CO₂分离, 多孔材料, 聚醚嵌段聚酰胺（Pebax）, 混合基质膜, 稳定性