UiO-66-polyether block amide mixed matrix membranes for CO2 separation

Abstract Mixed matrix membranes containing metal-organic frameworks have attracted large attention owing to the combined advantages of high separation performance and easy processability. In this work, CO 2 -philic zirconium metal organic framework UiO-66 and UiO-66-NH 2 nanocrystals were synthesized and embedded into polyether block amide (PEBA) polymer membranes for CO 2 separation. It can be found that amine-functionalization endowed UiO-66-NH 2 nanoparticles with stronger CO 2 affinity compared with that of UiO-66. Also, the hydrogen bonding frameworks between UiO-66-NH 2 and PEBA were enhanced, leading to improved dispersibility in polymer matrix. Both the UiO-66-PEBA and UiO-66-NH 2 -PEBA mixed matrix membranes showed much higher CO 2 separation performance than that of pure PEBA membrane. Especially, amine functionalization of the porous frameworks provided the so-prepared UiO-66-NH 2 -PEBA mixed matrix membrane with higher CO 2 /N 2 selectivity and slightly decreased CO 2 permeability than those of UiO-66-PEBA membrane. The developed UiO-66-NH 2 -PEBA mixed matrix membrane (with MOFs loading of 10 wt%) was tested in humid state and showed excellent and stable CO 2 /N 2 separation performance (CO 2 permeability of 130 Barrer, CO 2 /N 2 selectivity of 72) surpassing the upper bound of polymer membranes. This type of UiO-66 based mixed matrix membranes featuring with excellent structural stability and significantly improved gas separation performance offer promising potential for CO 2 capture.