Poly(vinylidene fluoride) (PVDF) was modified by atom transfer radical polymerization (ATRP) directly from the secondary fluoride group of the PVDF backbone. 3-trimethoxysilyl propyl methacrylate (TMSPMA) was initiated to polymerization by copper (1) chloride (CuCl) and 4,4'-dimethyl-2,2'-dipyridyl (DMDP) in an N-methyl pyrrolidinone (NMP) solution. NMR, FTIR-ATR, and XRD spectra of the grafted polymers showed that the poly-(TMSPMA) (PTMSPMA) side chains were successfully grafted to the PVDF backbone. The membranes prepared using the modified PVDF showed higher flux than the unmodified PVDF membrane. The hydrolysis of the membrane prepared from the silyl functional PVDF resulted in an increase of the pore size and a quaternary pore size distribution. (c) 2008 Elsevier Ltd. All rights reserved.