Ren Yanxiong, Chong Boyang, Xu Wei, Zhang Zhengqing, Liu Lin, Wu Yingzhen, Liu Yutao, Jiang Haifei, Liang Xu, Wu Hong, Zhang Hongjun, Ye Bangjiao, Zhong Chongli, He Guangwei, Jiang Zhongyi
Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China.
Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
Innovation (Camb). 2022 Oct 12;3(6):100334. doi: 10.1016/j.xinn.2022.100334. eCollection 2022 Nov 8.
Polymers of intrinsic microporosity (PIMs), integrating unique microporous structure and solution-processability, are one class of the most promising membrane materials for energy-efficient gas separations. However, the micropores generated from inefficient chain packing often exhibit wide pore size distribution, making it very challenging to achieve efficient olefin/paraffin separations. Here, we propose a coordination-driven reconstruction (CDR) strategy, where metal ions are incorporated into amidoxime-functionalized PIM-1 (AO-PIM) to generate coordination crosslinking networks. By varying the type and content of metal ions, the resulting crosslinking structures can be optimized, and the molecular sieving capability of PIM membranes can be dramatically enhanced. Particularly, the introduction of alkali or alkaline earth metals renders more precise micropores contributing to superior CH/CH separation performance. K incorporated AO-PIM membranes exhibit a high ideal CH/CH selectivity of 50, surpassing almost all the reported polymer membranes. Moreover, the coordination crosslinking structure significantly improves the membrane stability under higher pressure as well as the plasticization resistant performance. We envision that this straightforward and generic CDR strategy could potentially unlock the potentials of PIMs for olefin/paraffin separations and many other challenging gas separations.
固有微孔聚合物（PIMs）兼具独特的微孔结构和溶液可加工性，是用于节能气体分离的最具前景的一类膜材料。然而，由低效链堆积产生的微孔通常呈现宽孔径分布，这使得实现高效的烯烃/石蜡分离极具挑战性。在此，我们提出一种配位驱动重构（CDR）策略，即将金属离子引入偕胺肟功能化的PIM-1（AO-PIM）中以生成配位交联网络。通过改变金属离子的类型和含量，可以优化所得的交联结构，并显著增强PIM膜的分子筛能力。特别地，碱金属或碱土金属的引入产生了更精确的微孔，有助于实现卓越的C₂H₄/C₂H₆分离性能。掺入钾的AO-PIM膜表现出高达50的理想C₂H₄/C₂H₆选择性，超过了几乎所有已报道的聚合物膜。此外，配位交联结构显著提高了膜在较高压力下的稳定性以及抗塑化性能。我们设想，这种直接且通用的CDR策略可能会释放PIMs在烯烃/石蜡分离及许多其他具有挑战性的气体分离方面的潜力。
