Surface topography and composition of deuterated polystyrene-poly(bromostyrene) blends

Surface structure, obtained from atomic force microscopy and X-ray reflectivity, and surface chemical analysis data, obtained from X-ray photoelectron and static secondary ion mass spectroscopy, are reported for blends of poly (p-bromostyrene) with poly(deuteriostyrene). When high speeds are used in the spin-coating process, the atomic force microscopy measurements reveal that the surface structure consists of islands, the distribution and number changing with the poly(bromostyrene) content. A ribbon structure is observed at just above 50% (w/w) poly(bromostyrene) in the mixture. These ribbons merge to form more continuous structures, leaving voids at higher concentrations. X-ray reflectivity data from the films were consistent with the topographical features observed with the AFM. At low spinning speeds, continuous films with little or no topographical structure are formed. The islands observed at high spinning speeds are predominately poly(bromostyrene) and reflect the importance of thermodynamic and kinetic driving forces in their formation.