具有坚固孔隙结构的超疏水纳米纤维膜设计用于膜蒸馏

Design of superhydrophobic nanofiber membrane with robust pore structure for membrane distillation

膜蒸馏技术在海水淡化及高盐废水处理中展现出极大的优势与潜力,静电纺丝纳米纤维膜因其较高的水通量和较低的传质阻力引起了研究者们广泛的关注.但其疏松多孔的孔隙结构易受到水流剪切力的作用导致膜孔变形,引起膜孔润湿.本研究从膜的结构出发,对热压后的聚偏氟乙烯(PVDF)纳米纤维膜采用聚二甲基硅氧烷(PDMS)和TiO2纳米颗粒(TiNPs)混合溶液浸渍涂覆,制备出了具有坚固孔隙结构的超疏水纳米纤维膜.该膜接触角高达160.3°,具有良好的膜蒸馏性能,在测试中表现出了39.3 kg/(m^(2)·h)的高水通量和长达102 h的耐久性,且截留率大于99.99%,为今后膜蒸馏膜的设计提供了一定的指导意义.

Membrane distillation(MD)technology shows excellent advantages and potential in seawater desalination and high saline wastewater treatment,and electrospun nanofiber membranes have attracted extensive attention from researchers due to their high water flux and low mass transfer resistance.However,its loose and porous pore structure is susceptible to deformation of membrane pores caused by the shear force of water flow,which leads to wetting of membrane pores.In this study,we prepared superhydrophobic nanofiber membranes with a robust pore structure by impregnating and coating polyvinylidene fluoride(PVDF)nanofiber membranes with a mixture of polydimethylsiloxane(PDMS)and TiO2 nanoparticles(TiNPs)after hot pressing.The membrane has a contact angle of up to 160.3°and excellent membrane distillation performance,as well as high water flux of 39.3 kg/(m^(2)·h)and durability up to 102 h in MD with a retention rate of more than 99.99%,which provides some guidance for the design of MD membranes in the future.