Determination of surface glass transition temperature of monodisperse polystyrene based on temperature-dependent scanning viscoelasticity microscopy

The thermal molecular motion at the outermost surface of the polystyrene (PS) film was measured directly on the basis of temperature-dependent scanning viscoelasticity microscopy (SVM). It was possible to compare directly the surface and bulk thermal molecular motions of the polymeric solid film. The comparison lead to the conclusion that the surface is in a glass-rubber transition state or a rubbery state even at room temperature.