关键词: 金属有机骨架, 柠檬酸铵, 水稳定性, 混合基质膜, 气体分离

Abstract:

As a potential separation material, metal-organic frameworks (MOFs) have its unique pore structure, high adaptability and selectivity, and have a broad application prospect in the field of membrane separation. However, MOFs are vulnerable to damage in humid environments, which severely limits their application in membrane separation. Therefore, improving the water stability of MOFs is one of the important problems in realizing its application in the field of membrane separation. In this paper, Cu-BTC-AC filler with high water stability was prepared by the functionalization of ammonium citrate and MMMs with different filler content were prepared by embedding the obtained Cu-BTC-AC in Pebax 1657 matrix. The CO₂/N₂ separation performance of the Cu-BTC-AC/Pebax MMMs at 25℃ under humid condition was examined. Compared with the pure Pebax membrane, the prepared MMMs show improved CO₂ permeability and CO₂/N₂ selectivity, with an optimized CO₂ permeance of 776.5 GPU accompanied by the CO₂/N₂ selectivity of 46.7. Besides, the high water stability of the filler originated from AC functionalization endows the prepared MMMs with potential for application in practical industrial gas separations.

Key words: metal-organic framework, ammonium citrate, water-stability, mixed-matrix membrane, gas separation