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Publikation Nanoparticle-assisted, catalytic etching of carbon surfaces as a method to manufacture nanogrooves(American Chemical Society, 2012) Schumacher, Christoph M.; Koehler, Fabian M.; Rotzetter, Aline C. C.; Raso, Renzo; Stark, Wendelin J.A simple structuring method for graphitic structures based on the catalytic properties of cerium oxide nanoparticles under oxidizing conditions is presented. Highly oriented pyrolytic graphite chips were impregnated with well-dispersed ceria nanoparticles and then treated at elevated temperatures for several hours. Oxidation activities on the particle surface appeared as crystallographically independent traces that were formed on the graphite and provide a simple method to manufacture nanogrooves at large scale. By altering treatment durations and temperatures, the optimal conditions and activity parameters of the particles were determined. A systematic AFM evaluation allowed formulating of a mechanism of the etching process. The findings provide a simple procedure for the patterning of graphitic structures, formation of nanogrooves and thereby a basic tool for material science with respect to the manufacturing of atmospheric nanofilters and ion-selective membranes.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Development of a new reactor concept for oxidation reactions(Hochschule für Life Sciences FHNW, 2023) Lamanna Bürkler, Patrizia; Zogg, Andreas; DSM-FirmenichOxidation reactions comprises an important class of reactions. One key commercial product in DSM – Firmenich' s portfolio contains an oxidation step using 100% O2. Oxidation reactions are highly exothermic, often operated in an organic solvent. With a possible ignition source, this will lead to a high-risk potential regarding explosion. To obtain a safe process, it is desirable to avoid an explosive atmosphere, but this will cause limitations regarding process temperature and pressure. In reactions with 100% O2, very high explosion pressures must be expected. An inherently safe mode of operation is only possible if the apparatus were constructed to be pressure shock resistant and the process temperature is kept between a certain range. The goal of this master thesis is the development of a new reactor concept for gas-liquid phase reactions with focus on oxidation reactions. Based on the design of a loop-reactor, the gaseous oxidizing agent O2 is transferred to the liquid reaction mass using membrane technology. The concept keeps the liquid phase saturated with O2, while minimizing the creation of an explosive atmosphere inside the reactor. The approach of a head space free reactor is a significantly increase of process safety while minimizing the constraints with regards to the solvent selection and process conditions.11 - Studentische ArbeitPublikation Novel Reactor Technology for Large Scale Catalytic Oxidation(Hochschule für Life Sciences FHNW, 03.11.2020) Zogg, Andreas; Wegmann, Kai; Otter, BenjaminKupfer katalysierte Chan-Lam Kupplung mit reinem Sauerstoff als Oxidationsmittel. Durchführung Rührkessel und im Loop-Reaktor.05 - Forschungs- oder Arbeitsbericht