Preparation, characterization and performance of polyvinylidene fluoride/tetraoctyl phosphonium bromide nanocomposite ultrafiltration membrane

Ultrafiltration (UF) membrane is widely used in many industrial areas and applications. Polyvinylidene fluoride (PVDF) is one of the commonly used materials for UF membrane fabrication due to its excellent properties. However, its hydrophobic nature causes the decrease of its demands and limits its applications. Hence, tetraoctyl phosphonium bromide (TOPBr) clay was used as a nanofiller material and was added into the PVDF matrix to decrease the hydrophobic surface through the antifouling properties of the PVDF/TOPBr nanocomposite membrane. The phase inversion process was employed for membrane fabrication which characterizes the water content and porosity of the PVDF/TOPBr nanocomposite UF membrane and to determine the performance of membrane in terms of pure water permeation, protein separation and fouling parameters. The results showed the increment of TOPBr dosage increases the water content and porosity, as well as enhances the porosity structure of PVDF/TOPBr nanocomposite membrane compared to the original PVDF membrane. The protein separation performance test revealed that after the addition of TOPBr, the flux increased from 2.06 L/m2 .h to 20.22 L/m2 .h with a 1.0 wt.% increase in protein separation as a result of the increase in the membrane hydrophilicity and porosity of the nanocomposite membrane. Moreover, PVDF/TOPBr1.0 nanocomposite showed the highest antifouling properties and flux recovery at 93% compared to other PVDF/TOPBr, as well as the native PVDF membrane