Glassy Dynamics and Heterogeneity of Polymer Thin Films

We review Our recent Studies on glassy dynamics and glass transition of polymer thin films using neutron and X-ray reflectivity and inelastic neutron techniques. In the last decade extensive studies have been performed oil polymer thin films to reveal very interesting but unusual properties such as reduction in the glass transition temperature T-g with film thickness and negative thermal expansivity for thin films below anout 25 mm, and often some contradictory experimental results have been reported. It is believed that a key to solve the controversial situation is to disclose heterogenous structure Or multi-layer structure in polymer thin films. In the review. therefore, We summarize our recent experimental results by neutron and X-ray reflectivity and inelastic neutron scattering, focusing oil the dynamic heterogeneity in polymer thin films.