Direct imaging for nanoparticle embedding to probe viscoelasticity of polymer surfaces

A simple way to directly measure qualitative dynamical properties of the near surface layer in polymeric materials is introduced. By design, the technique allows effects at different length scales to be differentiated and is able to provide a definition of the surface region probed. Thus, experiments performed on melt and glassy PS revel strong evidence for a meltlike layer of at least 3-4 nm at the surface of glassy PS films at a temperature at least 7K below the bulk Tg.