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

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 degrees) and slippery (water sliding angles as low as 4.5 degrees) 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.

Automated summary

In this study, a PVDF nanofibrous membrane with a liquid-like coating was successfully fabricated using a simple method. The uniform distribution of PDMS and TiO2 nanoparticles on the surface of the coating resulted in a membrane with superhydrophobic and slippery characteristics. Experimental results showed that the coated membrane effectively mitigated membrane scaling and wetting, while maintaining high permeability and selectivity, making it a promising candidate for durable membrane distillation applications.