Mixed-matrix hollow fiber composite membranes comprising of PEBA and MOF for pervaporation separation of ethanol/water mixtures

Pervaporation membrane technology plays an important role in production of renewable bio-fuels. To improve the separation performance of polymeric membranes, an effective approach is development of mixed-matrix membranes containing high-performing fillers such as metal-organic frameworks. Towards practical application, hollow fiber could be an ideal substrate for mixed-matrix composite membrane, while current fabrications of this kind of composite membrane are relative complicated and challenging. In this work, a novel ceramic hollow fiber supported mixed-matrix composite membrane made of RHO-[Zn(eim)2] (MAF-6, Heim = 2-ethylimidazole) nanoparticles and poly (ether-block-amide) (PEBA) was fabricated via a facile dip-coating approach. SEM, XRD, TGA, contact angle and swelling measurements, nano-scratch technique were employed to study the morphology, crystal structure, thermal stability, surface property and interfacial adhesion of the resulting MAF-6/PEBA mixed-matrix hollow fiber composite membranes, respectively. These membranes were applied for recovering ethanol from aqueous solution via pervaporation. The effects of MAF-6 loading, as well as operating conditions (e.g., temperature, feed concentration and long-term stability) on the PV performance were systematically investigated. The PV performance of PEBA membrane, both flux and separation factor, were remarkably enhanced by uniformly incorporating MAF-6 nanoparticles. Total flux of 4446 g/m 2 h and separation factor of 5.6 (feed: 5 wt% ethanol/water, 60 °C) was achieved for the optimized MAF-6/PEBA mixed-matrix hollow fiber composite membrane, which shows great advantages over the reported PEBA-based membranes for ethanol/water separation.