Synthesis, Characterization, and Properties of Tethered Polystyrene-b-polyacrylate Brushes on Flat Silicate Substrates

Surface-immobilized polystyrene- b -polyacrylate brushes have been synthesized on silicate substrates from chlorine-terminated polystyrene (PS) brushes by atom transfer radical polymerization (ATRP). ATRP of methyl methacrylate (MMA), methyl acrylate (MA), and ( N,N -dimethylamino)ethyl methacrylate (DMAEMA) produced tethered diblock copolymer brushes, which were characterized by ellipsometry, FTIR-ATR, tensiometry, and XPS. “Control” polymerizations supported a radical mechanism for the MMA polymerization. The thickness of the polyacrylate terminal block was controlled by free initiator concentration. All three diblock copolymer brushes underwent self-reorganization and exhibited different surface properties in response to different solvent treatments. For PS- b -PMMA and PS- b -PMA brushes, treatment with CH 2 Cl 2 resulted in localization of PMMA and PMA at the air interface; treatment with cyclohexane localized the PS block at the air interface. PS- b -PDMAEMA brushes exhibited a similar behavior using cyclohexane and THF/H 2 O (v/v = 1:1).