Imperfect perfection: Selective induction of CO2 during diffusion in mixed matrix membranes

Abstract

Metal-organic frameworks (MOFs) are one of the optimal choice to be endowed for designing high-performance CO2 separation membranes as the fillers, ascribing their unprecedented tunability and chemical functionalities. However, while pursuing more types of MOFs, researchers have slightly explored their inherent properties. Thus, we incorporated missing-linker defects into Zirconium Metal−Organic Framework for tailoring the superior CO2 transport channel through tune their microporosity. And a series of defect-engineered UiO-66 (UiO-AcOH) fillers were synthesized and mingled into PIM-based matrix with large free volume. Resistance model simulations and gas permeation tests confirmed that the defective UiO-66 can greatly improved the competitive adsorption of the dispersed phase in Mixed Matrix Membranes (MMMs), offering more degree of freedom for the transportation of CO2. At the optimal ratio, the CO2 permeability of the UiO-AcOH-1.4/PIM-15 wt% MMMs increased nearly 3.5 times (CO2 =11261 Barrer, and the CO2/N2 selectivity is 26, almost increasing 23% contrasted pure film. Moreover, MMMs possess excellent long-term working stability and anti-aging properties, showing excellent gas separation performance.