A càrrec de John M. Hutchinson (Departament de Màquines i Motors Tèrmics, ETSEIAT, UPC, Terrassa)
Organitza conjuntament CSIC-UB

Data: 29-04-2011
Hora: 12.00 h
Lloc: sala d'actes de l'Institut Jaume Almera

Descripció: The glass transition is discussed from a thermodynamic and phenomenological point of view. In particular, the kinetic nature of the transition and the non-equilibrium nature of the glassy state are considered, together with their implications for the properties of glassy materials. The measurement of the glass transition temperature, Tg, by differential scanning calorimetry (DSC) in particular, is discussed and the multiplicity of different definitions of Tg is addressed. Some fundamental aspects of the theoretical description of the glass transformation process are introduced, from which it is shown that the characteristic features of the glass transition can be modelled accurately if the basic aspects of non-linearity and non-exponentiality are included. Finally, the use of Temperature Modulated DSC (TMDSC) for the study of the glass transition is outlined, and the concept of a dynamic glass transition is discussed in contrast to the «thermal» glass transition of conve.