Glass transition in thin polymer films : A molecular dynamics study
F. Varnik, J. Baschnagel, K. Binder.
International Journal of Modern Physics C, 13, 799 , (2002)
A melt of nonentangled polymer chains confined between two smooth and purely repulsive walls is studied for various film thicknesses D and temperatures. The dynamics of the supercooled films is qualitatively identical to that of the bulk, but the walls lead to faster relaxation. To quantify this observation we analyze the data by the mode-coupling theory (MCT) of the glass transition. We find that the critical temperature of MCT, Tc(D), decreases with D and that T - Tc(D) is a relevant temperature scale. The static structure factor and dynamic correlation functions at intermediate times coincide with bulk behavior when compared to the same T - Tc(D).
Keyword(s): Glass transition; structural glasses; polymer dynamics; thin polymer films