Effect of type of poly(ethylene glycol) (PEG) based amphiphilic copolymer on antifouling properties of copolymer/poly(vinylidene fluoride) (PVDF) blend membranes

The antifouling properties of poly(vinylidene fluoride) (PVDF) membranes were investigated by blending several types of synthesized amphiphilic poly(poly(ethylene glycol) methyl ether methacrylate- methyl methacrylate) [P(PEGMA- MMA)] copolymers with different initial PEGMA/MMA monomer ratios and PEG side chain lengths. Many types of membranes were prepared using different copolymer/PVDF blend ratios via nonsolvent induced phase separation. The membranes with similar pure water permeabilities and surface pore sizes were prepared by controlling the dope solution composition. Thus, the bovine serum albumin antifouling properties could be assessed under similar hydrodynamic filtration conditions. The membrane hydrophilicity, surface PEGMA coverage, and antifouling properties of the prepared membranes increased with increasing copolymer/PVDF ratio and PEGMA/MMA monomer ratio of the copolymers and PEG length of the copolymer. A molecular dynamics simulation was performed to assess the surface chemical composition, and the results were compared with those of X-ray photoelectron spectroscopy. The antifouling properties depended more strongly on the membrane surface hydrophilicity when the copolymer chemical structures, that is, the PEGMA/MMA monomer ratio and PEG side chain length, were changed, rather than when the copolymer/PVDF blend ratio was changed.