Ultrathin and Switchable Nanoporous Catalytic Membranes of Polystyrene-b-poly-4-Vinyl Pyridine Block Copolymer Spherical Micelles

An easy fabrication of close-packed and block copolymer micelles-based ultrathin membranes for water purification, separation, catalytic, and dye degradation applications is reported. Nanoporous membranes based on the self-assembly of 2-(4'-hydroxybenzeneazo) benzoic acid (HABA)-polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) diblock copolymers supramolecular complexes are prepared by simple spin coating on pore-filled polyethylene terephthalate (PET) track-etched membranes. The prepared membranes are characterized by scanning electron microscopy, atomic force microscopy, transmission electron microscopy, and water permeation studies. The separation performance is studied by lysozyme protein rejection. The prepared membranes are also used to in situ synthesize gold nanoparticles in the corona of PS-b-P4VP spheres for catalytic activity towards the reduction of p-nitrophenol and degradation of congo red dye in flow through operation mode in a stirred cell membrane reactor. More than 95% reduction for p-nitrophenol and >98% degradation of Congo red at a sufficiently high flux indicates its suitability for catalytic transformation and environmental remediation applications.