Poly(vinylidene fluoride) Membranes with Hyperbranched Antifouling and Antibacterial Polymer Brushes

Graft copolymers of poly(vinylidene fluoride) (PVDF) with poly[2-( N, N -dimethylamino)ethyl methacrylate] (PDMAEMA) side chains (PVDF- g -PDMAEMA copolymers) were synthesized via activators generated by electron transfer for atom transfer radical polymerization (AGET-ATRP) of 2-( N, N -dimethylamino)ethyl methacrylate (DMAEMA) directly from the secondary fluorine atoms on the PVDF backbone. Microporous membranes were fabricated from the PVDF- g -PDMAEMA amphiphilic copolymers by phase inversion in an aqueous medium. After quaternization by propargyl bromide, the resulting PVDF- g -PQDMAEMA membrane and pore surfaces bearing pendant propargyl moieties could be further functionalized via surface-initiated alkyne–azide click reaction of azido-terminated hyperbranched polyglycerols (HPG-N 3 ) to form the PVDF- g -P[QDMAEMA- click -HPG] membranes. The PVDF- g -P[QDMAEMA- click -HPG] membranes exhibit good resistance to protein adsorption and fouling. Alternatively, alkyne–azide click reaction of azido-terminated polyethylenimine (PEI-N 3 ) on the PVDF- g -PQDMAEMA membranes, followed by quaternization with 1-bromohexane, produce the PVDF- g -P[QDMAEMA- click -QPEI] membrane which is effective in reducing bacterial growth and proliferation under continuous-flow conditions.