ZIF-71 as a potential filler to prepare pervaporation membranes for bio-alcohol recovery

Metal-organic frameworks (MOFs) are an emerging class of materials for potential use in separation. ZIF-71 has super-hydrophobic pore channels and a very flexible pore architecture, which make ZIF-71 a potential candidate for recovering bio-alcohols from fermentation broths. In the present study, mixed matrix membranes (MMMs) based on PDMS and ZIF-71 were prepared for separation of alcohols (methanol, ethanol, isopropanol (IPA) or sec-butanol) from aqueous solutions. Experimental results reveal that the pervaporation performance of the PDMS membrane was improved in both flux and separation factors upon embedment of ZIF-71. The pervaporation separation factors for alcohols of ZIF-71 filled the PDMS membrane (PDMS : ZIF-71 = 10 : 2) nearly double compared to those of unfilled PDMS membranes, suggesting that ZIF-71 is an excellent filler to prepare organophilic pervaporation membranes for bio-alcohol recovery.