Probing the surface viscoelasticity of polymer films

Glass transition temperature, one of the most important properties of amorphous polymers in many technological applications, exhibits deviation from bulk value for nanoconfined polymer thin films. Glass transition temperature deviation due to enhanced/ restricted polymer chain dynamics at the polymer surface or substrate interface has been probed by many different experimental techniques. In this paper, we describe recent experimental techniques which could probe the surface glass transition temperature of polymer thin films, their advantages and limitations, and organic thin-film transistor as a new tool to probe the surface viscoelasticity of polymer films.