Glass Transition at the Surface and Interface

Abstract

Glass transition is an important physical phenomena of polymeric materials, and the glass transition temperature (Tg) is often used as an index related to temperature. This chapter analyzes the Tg values of a thin film, polymer surface, and interface on a substrate by conducting a coarse-grained molecular dynamics simulation. There are several methods of estimating Tg using coarse-grained molecular dynamics simulation; here, the thickness of the film and mean square displacement of the bead are used to obtain the Tg values. Using mean square displacement analysis, we were able to estimate local Tg values, and we found that Tg increases in the order of surface < bulk < substrate interface.