Improved ethanol recovery through mixed-matrix membrane with hydrophobic MAF-6 as filler

Increasing the hydrophobicity of membrane was believed as an effective approach to enhance the performance of organophilic pervaporation (PV) membrane. In this work, the superhydrophobic alkyl group modificated metal organic framework (MOF) of RHO-[Zn(eim)2] (MAF-6) was incorporated into polydimethylsiloxane (PDMS) polymer to fabricate mixed matrix membranes (MMMs). The morphologies, physical and chemical properties of as-prepared MAF-6 nanocrystals and membranes were characterized with XRD, FESEM, EDX, QCM, contact angle and nano-scratch tests. The pervaporation experiments of ethanol/water mixture show the simultaneously enhanced flux and separation factor of MMMs compared with PDMS pristine membrane (with the optimal flux of 1200 g/m2 h1, and separation factor of 14.9), which stems from the hydrophilicity and high porosity of MAF-6, successfully overcoming the trade-off effect.