ZIF-8 incorporated polyether block amide membrane for phenol permselective pervaporation with high efficiency

Abstract

Abstract In recent years, zeolitic imidazolate framework-8 (ZIF-8) has received tremendous attention due to its hydrophobic inner channels and good compatibility with the polymer as an inorganic filler for preparation of the mixed matrix membrane (MMM). In this study, ZIF-8 particles were synthesized and incorporated into Ploy (ether block amide) matrix (PEBA-2533) to fabricate a MMM for the enhancement of phenol permselective pervaporation. The structure and morphology of ZIF-8 particle and the obtained MMMs were characterized by XRD, SEM, FTIR, contact angle and BET. It is found that the hydrophobicity of the membrane was enhanced by the incorporation of hydrophobic ZIF-8, and the obtained MMM withstand the extreme operation conditions of pervaporation. The effects of particle loading amount, feed concentration and temperature on the separation performance of ZIF-8 incorporated MMMs were investigated in details. Compared with the pure PEBA-2533 membrane, the permeate flux of ZIF-8 incorporated PEBA-2533 MMM with a 10 wt% loading amount was significantly increased from 846 g m−2 h−1 to 1310 g m−2 h−1, while the separation factor increased from 39 to 53 at 70 °C with 8000 ppm feed phenol concentration. The enhancement of the pervaporation performance could be mainly attributed to the preferential highly permeable regions of the bimodal membrane structure for phenol molecules, which was consisted of ZIF-8 particles. Finally, both of the excellent overall membrane pervaporation performance and the long-term revealed that such a ZIF-8 incorporated MMM has a great potential in separation and recovery of phenol from its aqueous solution for a practical process.