Polyvinylidene fluoride (PVDF) membranes as supports were in situ modified by surface-initiated electronic activation of regeneration atom transfer radical polymerization (SI-AGET ATRP) of 4-vinylpyridine (4VP) functional monomer.The pyridine pendant groups at the grafted P4VP side-chains were in turn entrapped with Keggin-type phosphotugnstic acid (H3PW12O40 nH2O

HPW) catalysts on modified membranes via electrostatic interaction to prepare a novel hybrid catalytic membrane.The results of the polymerizations demonstrated the features of living/controlled surface-initiated grafted polymerization and the grafted yields of poly(4-vinylpyridine) (P4VP) linearly increased with polymerization reaction times.The grafted yields reached to 2.25 mg/cm2 when the polymerization time was 16 h.And the same time

the lumpy structure aggregation appeared on the surface of modified membranes by reason of the collapse of tightly packed grafted P4VP with high grafted yields.Subsequently

the quaternization of the grafted P4VP with bromohexadecane was carried out to create the cationic composite membranes

containing dense and reactive quaternary ammonium pyridine groups.The pendant pyridine and pyridinium groups facilitated the electrostatic assembly of HPW onto the P4VP-grafted membranes.Supported-HPW catalysts were homogeneously loaded on the PVDF-g-QP4VP membrane surface and pores and maintained the primary Keggin structure.The water contact angles values of PVDF-g-QP4VP/HPW catalytic membranes decreased from 80.4 to 57.8

this result exhibited the significant effect on the wettability of membranes through loading the hydrophilic catalysts.