Local modification of elastic properties of polystyrene–polyethyleneoxide blend surfaces

Modifications of the phase‐separated surface of polystyrene–polyethyleneoxide (PS‐PEO) blend films were carried out by using an atomic force microscope. On PEO, contrary to PS, a scanning of a tip with large forces of 50 nN resulted in a modification of surface and increased the elastic stiffness. The modification was seen as regular stripes perpendicular to the scanning direction, which may be caused by the rearrangement of the PEO folding structure as a result of a balance of various forces during scanning. This rearrangement may increase the density of the films and hence causes the increase of the elastic stiffness. On the stripes, molecular images were obtained with friction force microscope, reflecting the folding structure of PEO.