Functionalized PVDF Nanofiber Membranes for Desalination by Direct Contact Membrane Distillation

The recent combination of nano particles and polymer in fabricating polymeric membranes has shown immerse potentials in developing composite membrane materials for practical applications including pollutant sequestration, reverse osmosis and membrane distillation. Here, this study reports the functionalization of Polyvinylidene fluoride electrospun nanofibers by the addition of different nano fillers (CuO, TiO2, SiO2 and MOF-F300). The composite membrane materials were tested to determine their capability in the production of portable water from seawater by direct contact membrane distillation. Though the MOF composited membranes had the highest porosity, the flux shown by the TiO2 composited membrane was greatest amongst all the composites (up to 7.2 kg/m2·h) at a temperature difference of 27oC. The salt rejection for a 35 g/L NaCl solution was >99.9% for all membranes tested with permeate conductivities surpassing the drinking water standard. The attachment of nanofiber and support was significantly improved which is a key functionality in predicting long-term membrane durability, filler compatibility and flux stability of substrate composited membranes. This class of functionalized membranes materials are promising candidates for desalination and other membrane base applications.