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O: Fachverband Oberflächenphysik
O 55: Poster Session III - MA 141/144 (Methods: Atomic and Electronic Structure; Particles and Clusters; Heterogeneous Catalysis; Semiconductor Substrates: Epitaxy and Growth+Adsorption+Clean Surfaces+Solid-Liquid Interfaces; Oxides and Insulators: Solid-Liquid Interfaces+Epitaxy and Growth; Phase Transitions; Metal Substrates: Adsorption of Inorganic Molecules+Epitaxy and Growth; Surface Chemical Reactions; Bimetallic Nanosystems: Tuning Physical and Chemical Properties; Oxides and insulators: Adsorption; Organic, polymeric, biomolecular films; etc.)
O 55.77: Poster
Mittwoch, 27. Februar 2008, 18:30–19:30, Poster F
Surface investigations of wood constituents and wood-based compounds — •Thomas Haensel1, Andreas Comouth1, Nicolas Zydziak2, Pierre Lorenz1, Syed Imad-Uddin Ahmed1, Stefan Krischok1, Axel Kauffmann2, and Juergen A. Schaefer1 — 1Institut für Physik and Institut für Mikro- und Nanotechnologien, TU Ilmenau, P.O. Box 100565,Germany — 2Fraunhofer Institut für Chemische Technologie (ICT), Joseph-von-Fraunhofer-Straße 7, 76327 Pfinztal, Germany
Graphite is a common bipolar plate material in direct methanol fuel cells. However, the graphite used is synthetically manufactured in an energy intensive and costly process. Efforts are underway to replace synthetic graphite with pyrolyzed compounds that consist largely of natural wood-based components. In this study, the surface characteristics of unpyrolyzed and pyrolyzed cellulose and lignin were investigated using contact angle measurements and X-ray photoelectron spectroscopy. Since an important consideration for any replacement material is its reactivity to methanol, the adsorption process on these surfaces was also examined by offering methanol. All results were compared with highly oriented pyrolytic graphite. The results indicate that methanol does not react in any significant manner with the pyrolyzed surfaces. The charging and X-ray degradation problems associated with the study of native compounds are also discussed.