Preparation of PVDF porous membranes by using PVDF-g-PVP powder as an additive and their antifouling property

The hydrophilic PVDF-g-PVP powder was used as additive to prepare a series of PVDF/PVDF-g-PVP blend porous membranes via an immersion precipitation phase inversion process. FTIR-ATR measurements confirmed that the hydrophilic PVP preferentially segregated to the interface between membrane and coagulant. SEM images showed that there was no big change in the membrane cross-section with the amount of PVDF-g-PVP increased. However, the membrane surface roughness increased with the amount of PVDF-g-PVP increased according to AFM data. The mean pore size of membranes reached max when the amount of PVDF-g-PVP was 10 wt%. The water contact angle and filtration experiments revealed that the surface enrichment of PVP endowed the membranes with significantly enhanced surface hydrophilicity and protein-adsorption resistance. The flux recovery of the porous membranes was increased from 37.50% to 77.23% with the amount of PVDF-g-PVP increased from 0 to 50 wt%, also indicating that the antifouling property of the porous membranes was improved.

► The hydrophilic PVDF-g-PVP powder is used as additive to prepare PVDF/PVDF-g-PVP blend porous membranes.
► The immersion precipitation phase inversion process is adopted to prepare the blend membranes.
► The hydrophilicity of the porous membranes surface is enhanced with increasing the amount of PVDF-g-PVP.
► The pure water flux of the porous membranes depends on the amount of PVDF-g-PVP in the porous membranes.
► Antifouling property of the porous membranes is improved obviously comparing with a pristine PVDF membrane.