Surface modification of polyvinylidene fluoride membrane for enhanced wetting resistance

Modifications of polyvinylidene fluoride (PVDF) membranes were carried out to improve both hydrophobicity and stability through four steps: pore expansion by a plasma treatment, hydroxylation of the membrane by the Fenton reaction, generation and growth of microparticles (MPs) on the hydroxylated functional groups in pores, and hydrophobic modification. The membranes modified by the methods proposed in this study did not lose their hydrophobicity and maintained the flux over a significantly longer period. The PVDF membrane modified by hydrophobic MPs attached inside enlarged pores exhibited a minimized flux reduction and significantly higher antiwetting stability.