Figure 3: X-ray photoelectron spectroscopy (XPS) depth profiles of neat (I) and (I)/polystyrene (40/60 wt%) films.

(a,b) are depth profiles of elements (C, S, O and Si) in respectively neat (I) and (I)/polystyrene film; (c) relative concentrations of carbon as a function of film depth in neat (I) and (I)/polystyrene film; and (d) relative concentrations of sulfur as a function of film depth in neat (I) and (I)/polystyrene film.