Investigation of the Surface Glass Transition Temperature by Embedding of Noble Metal Nanoclusters into Monodisperse Polystyrenes
| Autor: | Franz Faupel, J. Erichsen, Jörn Kanzow, Kai Dolgner, K. Günther-Schade, Thomas Strunskus, Ulrich Schürmann, Vladimir Zaporojtchenko |
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| Rok vydání: | 2004 |
| Předmět: |
chemistry.chemical_classification
Polymers and Plastics Organic Chemistry Analytical chemistry Mineralogy Polymer engineering.material Nanoclusters Inorganic Chemistry chemistry.chemical_compound Differential scanning calorimetry X-ray photoelectron spectroscopy chemistry Materials Chemistry engineering Noble metal Dewetting Polystyrene Glass transition |
| Zdroj: | Macromolecules. 37:1831-1838 |
| ISSN: | 1520-5835 0024-9297 |
| Popis: | Chain mobility in a near surface region at a polystyrene/vacuum interface was investigated by embedding of noble metal nanosized clusters. The embedding process was monitored in situ by X-ray photoelectron spectroscopy. The embedding of nanosized clusters needs long-range chain mobility of the polymer. Therefore, the embedding process is a probe for the glass transition in a near surface region. The clusters used in this study are formed by the dewetting of evaporated noble metals onto the polymer surface. First, methodical influences on the embedding process were investigated. An onset embedding temperature T* was defined. T* increases with a heating rate comparable to Tg(bulk) determined with a differential scanning calorimeter. Furthermore, T* increases with nominal metal coverage which results in increasing average cluster radius. The cluster size distribution was investigated by transmission electron microscopy. It is shown that T* is an upper limit for Tg in a near surface region with a depth of a f... |
| Databáze: | OpenAIRE |
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