AFM Study of Tethered Polystyrene-b-poly(methyl methacrylate) and Polystyrene-b-poly(methyl acrylate) Brushes on Flat Silicate Substrates

Atomic force microscopy (AFM) has been used to study tethered polystyrene - b -poly(methyl methacrylate) (PS - b -PMMA) and polystyrene - b -poly(methyl acrylate) (PS - b -PMA) brushes on flat substrates. The PS - b -PMMA surface was smooth after treatment with CH 2 Cl 2; treatment with cyclohexane led to a relatively rough surface, more obvious in a brush with a thinner PMMA layer. PS - b -PMA brushes exhibited a different nanomorphology after treatment with CH 2 Cl 2, which is may be due to the higher Flory−Huggins interaction parameter between PS and PMA. Treatment of a PS - b -PMMA brush with 30 nm PS and 10 nm PMMA with mixed solvents of CH 2 Cl 2 and cyclohexane resulted in a variety of morphologies including a smooth surface, a rough surface, a very rough surface with irregular structures, and a very rough surface with an unusual nanomorphology. The morphological scale was dependent on the thickness of the tethered diblock brushes.