Glass transition in Ultrathin Polymer Films : a Thermal Expansion Study
- The glass transition process gets affected in ultrathin films having thickness comparable to the size of the molecules. We observe systematic broadening of the glass transition temperature (T-g) as the thickness of an ultrathin polymer film reduces below the radius of gyration but the change in the average T-g was found to be very small. The existence of reversible negative and positive thermal expansion below and above T-g increased the sensitivity of our thickness measurements performed using energy-dispersive x-ray reflectivity. A simple model of the T-g variation as a function of depth expected from sliding motion could explain the results
| Author details: | Ullrich Pietsch, M. K. Bhattacharya, M. K. Sanyal, Thomas Geue |
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| Publication type: | Article |
| Language: | English |
| Year of first publication: | 2005 |
| Publication year: | 2005 |
| Release date: | 2017/03/24 |
| Source: | Physical Review / E. - 71 (2005), 4, S. 5 |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
| Peer review: | Referiert |
| Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik |
