Surface structure analysis of thin dewetted polymer blend films

The surface structure of thin polymer blend films of deuterated polystyrene (dPS) and polyparamethylstyrene (PpMS) after annealing above the glass tra nsition temperature was investigated. With scanning force microscopy (SFM) the surface topography originated by a dewetting process is detected. The s ample surface is covered with small droplets consisting of several polymer molecules. Utilizing grazing incidence small angle neutron scattering (GISA NS) the topographical information as well as the in-plane composition is pr obed. For thin confined blend films a substructure of the droplets resultin g from an additional phase separation process at different length scales is detected.