Adjustable pervaporation performance of Zr‐MOF/poly(vinyl alcohol) mixed matrix membranes

BACKGROUND: Polymer membranes often display trade‐off effects between permeation flux and separation factor in pervaporation, and exploring the strategies for breaking the effects is crucial. In this study, by altering the organic linkers (1,4‐benzenedicarboxylate acid, 2‐hydroxyterephthalic acid, 2,5‐dihydroxyterephthalic acid and biphenyl‐4,4‐dicarboxylate), UiO‐66, UiO‐66‐OH, UiO‐66‐(OH)₂ and UiO‐67 were prepared and incorporated in poly(vinyl alcohol) (PVA) membranes for pervaporation of 90 wt% ethanol solution for the first time. RESULTS: The membrane properties and pervaporation performances were tuned, and anti‐trade‐off effects were demonstrated for UiO‐66/PVA, UiO‐66‐OH/PVA and UiO‐66‐(OH)₂/PVA mixed matrix membranes (MMMs). For the UiO‐66‐(OH)₂/PVA MMM with 1.0 wt% loading, the permeation flux, separation factor and pervaporation separation index (PSI) were increased by 16, 14 and 32% respectively and the water permeance and selectivity were increased by 24 and 10% respectively, while the swelling degree in 90 wt% ethanol declined by 28% in comparison with that of pristine PVA membrane. CONCLUSION: The pervaporation performance of the UiO‐66‐(OH)₂/PVA MMM demonstrated good potential in alcohol dehydration. © 2018 Society of Chemical Industry