Nanodefects induced by nanoindentation on thin polystyrene (PS) films spin cast on silicon (Si) relax upon annealing at 110 °C. The relaxation process for low molecular weight PS is interpreted in terms of a curvature driven flow which leads to the measurement of a diffusion coefficient. The latter is compared with the expected Rouse predictions using (i) bulk Tgbulk and (ii) surface Tgsurf glass transition temperature data, found in the literature. Deviations from the Rouse predictions are observed when Tgbulk is used for the analysis of the data. On the contrary, excellent agreement with the Rouse model is reported when Tgsurf is used.
Bibliographical noteFunding Information:
Prior support by the Center for Interfacial Engineering (CIE), a National Science Foundation Engineering Research Center at the University of Minnesota is gratefully acknowledged.
Copyright 2008 Elsevier B.V., All rights reserved.
- Atomic force microscopy
- Surface defects
- Surface energy
- Surface relaxation and reconstruction
- Surface roughening