Fabrication of superhydrophilic PVDF hollow fiber membranes with a fish-scale surface for water treatment

Publication date: Available online 29 July 2019Source: Reactive and Functional PolymersAuthor(s): Huiju Shao, Yating Qi, Jifeng Cheng, Shuhao QinAbstractWith enhancing rejection and antifouling properties, the permeate flux of membranes is usually reduced during the surface modification. Here, a novel method is presented to break through the permeability-selectivity trade-off by grafting zwitterionic copolymers and constructing the fish-scale microstructures on the PVDF hollow fiber membrane surface. The surface microstructure was optimized by manipulating the reaction temperature. Mainly, the molecule chains of zwitterionic copolymers were regularly aggregated due to the intermolecular attractive electrostatic forces, forming the fish-scale microstructures. Excitingly, the pore size was not decreased but slightly increased due to the stretching resulted from different aggregates. In contrast with the original membrane, the water fluxes of the as-prepared membrane M2 and M3 were largely increased from 245.8 L/m2 h to 766.9 L/m2 h and 733.0 L/m2 h, and separation efficiencies of oil/water emulsion were also highly elevated from 46.5% to 99.3% and 98.4%, respectively. The antifouling performance was simultaneously enhanced, and the flux recovery ratios were increased from 37.9% to 97.2% and 95.6%. As expected, this study can offer novel insights into overcoming the trade-off.

Source: Reactive and Functional Polymers - July 30, 2019 Category: Chemistry Source Type: research