Highly efficient polymer–MOF nanocomposite membrane for pervaporation separation of water/methanol/MTBE ternary mixture

[Display omitted] •The PEK-c/ZIF-8 nanocomposite membranes are prepared by varying ZIF-8 loading.•The ZIF-8 nanocrystals have a narrow size distribution in the range of 20–40nm.•The incorporation of ZIF-8 adjusts structure and properties of the PEK-c membrane.•The ZIF-8 nanocrystals greatly enhance the permeability of the PEK-c membrane.•The nanocomposite membranes exhibit a great potential in the MTBE purification. Novel polymer–MOF nanocomposite membranes are prepared via the incorporation of ZIF-8 nanocrystals into cardo polyetherketone (PEK-c) for pervaporation separation of water/methanol/MTBE ternary mixtures. The ZIF-8 nanocrystals with 20–40nm size are synthesized for preparing membranes. The resulting membranes have ZIF-8 nanocrystals dispersed homogeneously and embedded in the membrane matrix with adjustable ZIF-8 loading of up to 20wt%. Moreover, the membranes have homogeneous microstructure, good thermal and mechanical stabilities. They show favorable pervaporation performances for separation of the water/methanol/MTBE mixtures. The incorporation of ZIF-8 greatly enhances the permeation flux. At the low ZIF-8 loading, the water selectivity increases and the total separation factor is very high and greater than 1.97×104. Typically, the membrane with 4wt% ZIF-8 has the total flux of 1.48kgμmm−2h−1, water and total separation factor of 181 and 1.97×104 respectively. The newly developed nanocomposite membranes have a great potential in high-efficient purification of MTBE.