Enhanced properties of PVDF nanofibrous membrane with liquid-like coating for membrane distillation

Abstract

Grafted poly(dimethyl siloxane) (PDMS) or fluorinated chains as liquid-like films have drawn much attention recently to render the substrate self-cleaning and lyophobic characteristics. Herein, novel PVDF nanofibrous membrane with liquid-like coating was facilely fabricated via one-step co-deposition of TiO2 nanoparticles (TiNPs) and a macromolecular coupling agent with PDMS side chains for membrane distillation. The fabricated PDMS-based coating and TiO2 nanoclusters distributed uniformly on the surface rendered the membrane both superhydrophobic (water contact angles as high as 150.4°) and slippery (water sliding angles as low as 4.5°) characteristics. Membrane distillation (MD) experiments showed that the coated membrane is highly effective in mitigating membrane scaling and wetting via hindering foulant deposition and fouling-releasing mechanisms, while simultaneously maintaining a permeability of as high as 34.5 L·m−2·h−1 and a selectivity of >99.99%. These results are competitive when compared with those of typical commercial membranes and related PVDF nanofibrous membranes, which makes the coated membrane a promising candidate for durable MD applications.