Towards nanoporous membranes based on ABC triblock terpolymers.

Block copolymers represent an exciting class of complex materials as they self-assemble into highly regular structures of nanoscopic dimensions. When prepared as thin films, such structures can be used for a variety of applications including lithographic masks or nanoporous membranes. Reported here are nanostructures in thin films of structurally analogous polybutadiene-block-poly(2-vinyl pyridine)-block-poly(tert-butyl methacrylate) (BVT) and polystyrene-block-poly(2-vinyl pyridine)-block-poly(tert-butyl methacrylate) (SVT) triblock terpolymers, which are synthesized via sequential living anionic polymerization. The morphological behavior of annealed SVT and BVT films is investigated by scanning force and electron microscopies. The difference in the terpolymer composition results in the formation of an ordered perforated lamella phase in SVT films and hexagonally packed core/shell cylinders in BVT films. Further, the BVT films show high potential for the fabrication of composite membranes using track-etched poly(ethylene terephthalate) macroporous filters as a support.