Mixed-Matrix Membrane Hollow Fibers of Cu₃(BTC)₂ MOF and Polyimide for Gas Separation and Adsorption

Abstract

Metal−organic framework (MOF) crystals of Cu3(BTC)2 with a high surface area (1396 m2·g−1) were synthesized and mixed with polyimide (PI) to prepare mixed-matrix membranes (MMMs) for gas separations. The PI−Cu3(BTC)2 blend was successfully spun into MMM hollow fiber by the dry/wet-spinning method. SEM images of the fiber cross sections revealed significant plastic deformation of the polymer matrix owing to the strong affinity between Cu3(BTC)2 and PI. The H2 permeance and the selectivity of H2 with respect to other gases such as N2, CO2, O2, and CH4 both increased markedly with increased Cu3(BTC)2 loading. At a loading of 6 wt % Cu3(BTC)2, the permeance of H2 increased by 45%, and the ideal selectivity increased by a factor of 2−3 compared to the corresponding values for pure PI.