| 초록 |
Thermal expansion coefficient (CTE) is one of the fascinating topics to determine the thermal and physical properties of polymer thin films. The CTE of polymer films have many deviations affected by the interfacial interaction between layers, but the affection of inter-relationship is weakened with increasing film thickness. In this study, we investigated the unusual CTE behavior of polystyrene (PS) films on grafted polymer brush to define the CTE affected by interfacial interactions with substrate. We used the end-functional hydroxyl polystyrene brush (PSOH) with various molecular weights to modify inter-relationship between the layers, and PS films were coated on brush layers with varied thickness. The CTE of polymer films was measured by using in-situ ellipsometry in a vacuum annealing chamber as a function of temperature. The accurate interaction between the substrate and polymer will be discussed by neutron reflectivity (NR) in terms of each layer. |
