ZnO Nanowires@PVDF nanofiber membrane with superhydrophobicity for enhanced anti-wetting and anti-scaling properties in membrane distillation

The anti-wetting and anti-scaling abilities of membrane are two critical properties for the membrane distillation. In this work, a superhydrophobic hybrid composite nanofiber membrane with the construction of hydrophobic ZnO nanowires on PVDF nanofiber membrane (P-ZnO@PVDF) based on hydrothermal method and chemical vapor deposition (CVD) was presented. Imitating the growth of grass was employed to enhance the adhesion between ZnO nanowires and PVDF nanofiber membrane. The P-ZnO@PVDF membrane exhibited high porosity, narrow pore size distribution, superhydrophobicity, anti-wetting and anti-scaling, owing to the slip and Cassie-Baxter state caused by introduction of hydrophobic ZnO nanowires. Moreover, the membrane with robust durability presented the salt rejection of 99.9% and a stable permeation flux of 15.7 L m(-2) h(-1) for simulated seawater at the feed temperature of 60 degrees C and the distillate temperature of 20 degrees C after 60 h operation. The hybrid composite nanofiber membrane is to be a potential candidate for long-term operation of membrane distillation.