Preparation of Non-woven Fabric Reinforced Poly(vinylidene fluoride) Composite Membranes for Water Treatment

To optimize the mechanical properties of polymeric membranes fabricated by non-solvent induced phase separation (NIPS), a non-woven fabric has been used to reinforce the composite membrane. However, it remains a challenge to prepare an intact polymer membrane on the non-woven fabric because casting dopes usually spread into the porous substrate. Herein, a kind of non-woven fabric reinforced poly(vinylidene fluoride) (PVDF) composite membrane was fabricated by using poly(vinyl pyrrolidone) (PVP) to control the viscosity of casting dopes. Additionally, the effects of non-woven fabric on the membrane structure and properties were explored in the light of dynamics during the phase inversion process. A porous skin layer and long finger-like pores were successfully created on the surface and inner of membranes when 6 wt% PVP was added in the casting dopes. Compared with pure PVDF membranes, the pure water flux of the resultant membrane was elevated from 49.9 L/m 2 h to 656 L/m 2 h, BSA rejection from 40.5 % to 86.4 %, and flux recovery ratio (FRR) from 58.7 % to 86.1 %. More importantly, it also possessed outstanding mechanical properties, which far outperforms the results reported in some literatures. This study suggests a promising strategy to fabricate PVDF composite membranes with preeminent properties for wastewater treatment.