2D Covalent Organic Framework Membranes for Liquid-Phase Molecular Separations: State of the Field, Common Pitfalls, and Future Opportunities.
2D Covalent Organic Framework Membranes for Liquid-Phase Molecular Separations: State of the Field, Common Pitfalls, and Future Opportunities.
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用于液相分子分离的二维共价有机框架膜：该领域的现状、常见陷阱和未来机遇。
DOI：
10.1002/adma.202300525
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Burke DW
中科院分区：
文献类型：
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作者：
Burke DW
2D共价有机框架（2D COF）由于其坚固的连接和均匀的可调孔而成为下一代膜的有吸引力的候选者。许多出版物声称通过COF孔实现选择性分子传输，但类似网络的报告性能指标差异很大，在一些情况下，报告的实验不足以支持这样的结论。这些问题需要重新评估文献。用于液相分离的2D COF膜的公开实例可大致分为两类，每一类具有共同的性能特征：多晶COF膜（大多数厚度>1 µm）和弱结晶或非晶膜（大多数厚度<500 nm）。这两类都没有证明设计的COF孔结构和分离性能之间的一致关系，这表明这些不完美的材料不能通过均匀的孔筛选分子。从这个角度来看，严格的做法，用于评估COF膜结构和分离性能的描述，这将有利于他们的发展，对分子精确的膜能够执行以前未实现的化学分离。在缺乏这种更严格的证据标准的情况下，COF基膜的报告应持怀疑态度。随着控制2D聚合的方法的改进，精确的2D聚合物膜可以表现出与当代分离挑战相关的精致且节能的性能。
2D covalent organic frameworks (2D COFs) are attractive candidates for next‐generation membranes due to their robust linkages and uniform, tunable pores. Many publications have claimed to achieve selective molecular transport through COF pores, but reported performance metrics for similar networks vary dramatically, and in several cases the reported experiments are inadequate to support such conclusions. These issues require a reevaluation of the literature. Published examples of 2D COF membranes for liquid‐phase separations can be broadly divided into two categories, each with common performance characteristics: polycrystalline COF films (most >1 µm thick) and weakly crystalline or amorphous films (most <500 nm thick). Neither category has demonstrated consistent relationships between the designed COF pore structure and separation performance, suggesting that these imperfect materials do not sieve molecules through uniform pores. In this perspective, rigorous practices for evaluating COF membrane structures and separation performance are described, which will facilitate their development toward molecularly precise membranes capable of performing previously unrealized chemical separations. In the absence of this more rigorous standard of proof, reports of COF‐based membranes should be treated with skepticism. As methods to control 2D polymerization improve, precise 2D polymer membranes may exhibit exquisite and energy efficient performance relevant for contemporary separation challenges.