Mixed matrix membrane for enhanced Ethanol/Water pervaporation separation by incorporation of hydrophilic Zr-MOF NU-906 in chitosan

Conquering the trade-off between selectivity and permeability is crucial for efficient ethanol dehydration. The sophisticated metal–organic frameworks (MOFs) have proven their potential as membrane fillers despite of the limited research on few frameworks. Herein, in order to achieve enhanced water permselectivity, hydrophilic zirconium-based NU-906 nanoparticles were incorporated into chitosan (CS) to fabricate NU-906/CS mixed matrix membranes (MMMs) for alcohol dehydration. The introduction of NU-906 brought excellent water affinity and structural stability to the hybrid membranes confirmed by the water contact angle and swelling resistance tests. Benefiting from the hydrophilicity and the ordered porosity of the incorporated NU-906, simultaneously enhanced water selectivity and permeability have been achieved on the hybrid membranes. The optimum membrane with 5.0 wt% NU-906 exhibited a high flux of 1086 g/(m2·h) and an excellent separation factor of 2651 for 90 wt% ethanol dehydration at 76 ℃. This research has expanded the range of MOFs available for the fabrication of MMMs and provided new options for organic solvent pervaporation dehydration.