Electrospun PVDF nanofibre membranes for desalination of brackish water in membrane distillation

摘要

Membrane distillation has emerged as a highly efficient process in desalination of saline water. However, this process is affected by wetting of membrane pores and the low porous nature of membranes, causing low rate of water recovery. This study sought to mitigate these challenges by synthesizing highly porous and super-hydrophobic polyvinylidene fluoride (PVDF) nanofibre membranes modified with organically functionalized silica (SiO_2) nanoparticles (NPs). The highly porous nanofibre membranes were synthesized using an electrospinning technique. The membranes were found to be mechanically strong and porous. Addition of the organically modified SiO_2 NPs to the electrospinning solution resulted in the formation of super-hydrophobic membranes. These membranes were tested for their salt rejection capacity and water fluxes. They were found to reject the salt ions from water at high efficiencies (> 99%) with water fluxes ≈ 64 litres per hour indicating their capacity to produce high purity water in large quantities.