Characterization of the structured PMMA films. (A) AFM topographical image of PMMA3 surface, structured using the polymer demixing technique. (B) XPS C1s spectrum of a surface of pure PMMA. The spectrum is the result of the convolution of four peaks, indicated in numbers on the PMMA molecules. (C) XPS C1s spectrum of a pure PS surface. (D) XPS C1s spectrum of a surface similar to PMMA3 (black line). For comparison the spectrum relative to pure PMMA is shown (dashed line), together with the difference between the two spectra (in gray), computed overlapping the ester peaks at 289.1 eV of the two spectra, that contain the contribution of the solely PMMA.