Microfiber aligned hollow fiber membranes from immiscible polymer solutions by phase inversion

In this study, we report for the first time a pioneering method to prepare membranes with a fibrous morphology via phase inversion with extremely high pore connectivity. Microfiber aligned hollow fiber membranes were prepared via a polymer blend solution consisting of poly (vinylidene fluoride) with polysulfone in PolarClean® as a green solvent. The microfiber structure appeared only when controlled phase separation was performed with polymer blends. A systematic analysis has revealed that the shear rate and the reduced capillary number (?) of a blend solution significantly affected the morphology of the final membrane. The fabricated fibrous membranes exhibited six-fold higher water productivity compared to the best electrospun membranes reported in the literature, yet they remain highly scalable.