Preparation and Characterization of Multi-layer Poly(arylene sulfide sulfone) Nanofibers Membranes for Liquid Filtration

Owing to the excellent filtration performance and low energy cost, polymeric nanofibers microfiltration (MF) membranes have attracted increasing attentions. Poly(arylene sulfide sulfone) (PASS), as one of the structurally modified polymers based on poly-(phenylene sulfide) (PPS), has been selected as the raw material to fabricate nanofibers MF membranes via electrospun techniques. The effects of PASS solution and the electrospinning processing parameters on the structural morphology of nanofibers were investigated in detail. The average diameter of PASS nanofibers was (296 ± 46) nm under the optimal condition: polymer concentration of 0.27 g·mL−1 PASS/DMI, applied voltage of 20 kV, and speed of collector drum of 300 r·min−1. And then the multi-layer PASS nanofibers MF membranes were fabricated from cold-pressing the optimized PASS nanofibers (as-prepared PASS nanofibers) membrane. The morphology, porosity, pore size, mechanical properties, and surface wettability of the multi-layer PASS nanofibers MF membranes could be tuned by the layers of as-prepared nanofibers membrane. The results demonstrated that the membrane with 6 layers (marked as PASS-6) exhibited the smallest porosity, smallest pore size, highest mechanical property, and best surface wettability. Meanwhile, the multi-layer PASS nanofibers MF membranes showed that the rejection ratio gradually increased, while the pure water flux decreased with increasing membranes thickness. The PASS-6 membrane exhibited large water flux of 747.76 L·m−2·h−1 and high separation efficiency of 99.9% to 0.2 µm particles, making it a promising candidate for microfilter.