Effect of Long Range Interactions on the Glass Transition Temperature of Thin Polystyrene Films

The glass transition temperature (T_g) of thin polystyrene (PS) films supported on silicon wafers with oxide layers of varying thickness was characterized by the temperature dependence of the film thickness using ellipsometry. This allowed us to uncover how a long-range interaction affects the T_g of polymer films. As previously reported using a variety of methods, the T_g decreased with decreasing film thickness. However, the extent was not the same among the reports. In this study, we found that the T_g attenuation of a PS film of a given thickness was dependent on the oxide layer thickness of the silicon wafer via the long-range interaction.