Yu Zijun, Sun Yuxiu, Zhang Zhengqing, Geng Chenxu, Qiao Zhihua
School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China.
State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin 300387, China.
Polymers (Basel). 2024 Sep 9;16(17):2545. doi: 10.3390/polym16172545.
The exploitation of high-performance membranes selective for propylene is important for developing energy-efficient propylene/propane (CH/CH) separation technologies. Although metal-organic frameworks with a molecular sieving property have been considered promising filler materials in mixed-matrix membranes (MMMs), their use in practical applications has been challenging due to a lack of interface compatibility. Herein, we adopted a surface coordination strategy that involved rationally utilizing carboxyl-functionalized PIM-1 (cPIM) and ZIF-8 to prepare a mixed-matrix membrane for efficient propylene/propane separation. The interfacial coordination between the polymer and the MOF improves their compatibility and eliminates the need for additional modification of the MOF, thereby maximizing the inherent screening performance of the MOF filler. Additionally, the utilization of porous PIM-1 guaranteed the high permeability of the MMMs. The obtained MMMs exhibited excellent separation performance. The 30 wt% ZIF-8/cPIM-1 membrane performed the best, exhibiting a high CH permeability of 1023 Barrer with a moderate CH/CH selectivity of 13.97 under 2 bars of pressure. This work presents a method that can feasibly be used for the preparation of defect-free MOF-based MMMs for specific gas separations.
开发对丙烯具有选择性的高性能膜对于发展节能型丙烯/丙烷（CH₃/CH₃）分离技术至关重要。尽管具有分子筛特性的金属有机框架被认为是混合基质膜（MMMs）中很有前景的填充材料，但由于缺乏界面相容性，其在实际应用中一直具有挑战性。在此，我们采用了一种表面配位策略，即合理利用羧基功能化的PIM-1（cPIM）和ZIF-8来制备用于高效丙烯/丙烷分离的混合基质膜。聚合物与金属有机框架之间的界面配位改善了它们的相容性，并且无需对金属有机框架进行额外改性，从而使金属有机框架填料的固有筛分性能最大化。此外，多孔PIM-1的使用保证了混合基质膜的高渗透性。所获得的混合基质膜表现出优异的分离性能。30 wt% ZIF-8/cPIM-1膜性能最佳，在2巴压力下表现出1023 Barrer的高CH₃渗透性以及13.97的适度CH₃/CH₃选择性。这项工作提出了一种可切实用于制备用于特定气体分离的无缺陷金属有机框架基混合基质膜的方法。
