The copolymer poly(vinylidene fluoride)graft-poly(4-vinylpyridine) (PVDF-g-P4VP) was prepared through the graft copolymerization of poly(vinylidene fluoride) with 4-vinylpyridine. Through the blending of the PVDF-g-P4VP copolymer with poly(N-isopropylacrylamide) (PNIPAm) in an N-methyl-2-pyrrolidone solution, PVDF-g-P4VP/PNIPAm membranes were fabricated by phase inversion in aqueous media. Elemental analyses indicated that the blend concentration of PNIPAm in the blend membranes increased with an increase in the blend ratio used in the casting Solution. Scanning electron microscopy revealed that the membrane surface tended to corrugate at a low PNIPAm concentration and transformed into a smooth morphology at a high PNIPAm concentration. The surface morphology and pore size distribution of the microfiltration membranes could be regulated by the blend concentration of the casting Solution, temperature, pH, and ionic strength of the coagulation bath. X-ray photoelectron spectroscopy revealed a significant enrichment of PNIPAm on the membrane surface. The flux of aqueous solutions through the blend membranes exhibited a pH- and temperature-dependent behavior. (c) 2006 Wiley Periodicals, Inc.