Assembly of foam and honeycomb films of a diblock copolymer doped with Au or Ag nanoparticles at the liquid/liquid interface and their catalytic properties

Composite thin films of poly(t-butyl methacrylate)-block-poly(2-vinyl pyridine) (PtBMA-b-P2VP) doped with silver or gold nanoclusters or nanoparticles were fabricated at the liquid/liquid interface between the polymer chloroform solution and AgNO₃ or HAuCl₄ aqueous solution. The formation of the thin films results from the adsorption of the polymer molecules at the interface, combination with the inorganic species in the water phases, and self-assembly of the composite molecules. Different from homo-P2VP and polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) that self-assemble into foam film and honeycomb structure, respectively, two kinds of morphologies (foam and honeycomb structures) are formed simultaneously for PtBMA-b-P2VP, reflecting different assembling behaviors of these polymers at the interface. Silver or gold nanoclusters or nanoparticles were generated in the polymer films during the assembly process and further reduction of the combined precursors, which show high catalytic activity and durability for the reduction of 4-nitrophenol and other nitro-compounds.