Dynamic wetting of poly(ethylene oxide)-, PEO; grafted mica surface has been investigated by a tensiometric method based on the Wilhelmy balance. Advancing and receding contact angles were determined under static conditions as well as at different contact line velocities in the range 0.1-5.0 mm s-1. The wetting medium and conditions were chosen according to the phase behaviour of PEO determined in solution. Wetting parameters characterizing the surface/liquid interaction measured on a system below and above the theta conditions differ considerably. Contact angles of water or aqueous electrolyte solution were found to be increased while heterogeneity of the surface was reduced with increasing temperature and salt concentration stressing the role of chain mobility in the special properties of PEO surface. Dynamic wetting of poly(ethylene oxide)-, PEO; grafted mica surface has been investigated by a tensiometric method based on the Wilhelmy balance. Advancing and receding contact angles were determined under static conditions as well as at different contact line velocities in the range 0.1-5.0 mm s-1. The wetting medium and conditions were chosen according to the phase behaviour of PEO determined in solution. Wetting parameters characterizing the surface/liquid interaction measured on a system below and above the theta conditions differ considerably. Contact angles of water or aqueous electrolyte solution were found to be increased while heterogeneity of the surface was reduced with increasing temperature and salt concentration stressing the role of chain mobility in the special properties of PEO surface.