Regensburg 2002 – wissenschaftliches Programm
CPP 17.2: Vortrag
Donnerstag, 14. März 2002, 10:00–10:20, H39
Dispersion of Noble Metal Nanoclusters in Bisphenol-(A)-polycarbonate by Acetone Vapor Sorption and Crystallization — •Kai Dolgner1, Krzysztof Koziol1, Vladimir Zaporojtchenko1, Zhongyong Fan1, Jörn Kanzow1, Angelika Büttner1, Franz Faupel1, and Shigehito Deki2 — 1Lehrstuhl für Materialverbunde, Technische Fakultät der Universität Kiel, Kaiserstr. 2, 24143 Kiel, Germany — 2Department of Chemical Science and Engineering, Kobe University, Rokkodai-cho, Nado-ku, Kobe 657-8501, Japan
If noble metal (e.g. copper or gold) is evaporated onto amorphous bisphenol-(A)-polycarbonate the polymer surface will be covered by nanocluster and not by a continuous initially metal layer. These clusters can be dispersed into the bulk by acetone vapor induced crystallization of the polymer. The embedding and dispersion of gold was analyzed with depth profiling X-ray photoelectron spectroscopy, transmission electron microscopy, and atomic force microscopy. The time scale for sorption and crystallization were determined by mass-uptake and absorption measurements. We will present a tentative model of the dispersion process. The penetrating organic vapor provides the long-range mobility to the polymer chains, which now can rearrange into the energetically preferred crystalline state. Initially the cluster are embedded by the lowering of the surface Gibbs free energy, later the crystallization appears to provide the mobility for the dispersion process. There are indications that this could be attributed to the stress occurring during the crystallization process.