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Summary Air-stable Co, Fe, and Fe/Co nanoparticles are accessible by thermolysis of the metal carbonyl precursors in the presence of aluminium alkyls and subsequent “smooth oxidation”. The structure of the particles was investigated by transmission electron microscopy (TEM, HRTEM), X-ray absorption spectroscopy (XAS), X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS), metastable impact electron spectroscopy (MIES), and small-angle neutron scattering (SANS). The peptization of the nanoparticles with suitable surfactants (oleic and lauric acid, sodium dioctylsulfosuccinate (AOT), LP-4 (a fatty acid condensation polymer), and KorantinSH (N-oleyl sarcosine)) yields magnetic fluids dispersed in carrier liquids such as toluene, kerosene, vacuum and mineral oils which are remarkably stable in air under ambient conditions. The resulting magnetic fluids show good magnetic properties. Several methods for the preparation of water-based MF are presented, e.g., formation of surfactant bilayers, using phase transfer agents, or surface modification with L-cysteine ethyl ester. Water-based metallic magnetic fluids have a high potential for a number of technical and biomedical applications. Technical applications of the Co-based ferrofluids in the field of positioning systems and magnetohydrostatic bearings were investigated. The results emphasize the scope of nanoparticulate ferrofluids having a metallic core.

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The disassembly of used goods is characterized by strongly varying quantities and a wide range of different kinds and states of products. Furthermore, the requirements of a disassembly system are determined by the disassembly object, by the process as well as by the disassembly system itself. As a result of the high labor costs in industrial countries and the huge amount of used goods, an automated disassembly is favored for the industrial disassembly. New methods for the programming of industrial robots have to be developed because the costs for a programming of small lot sizes are a key factor of the economic efficiency of small and medium sized enterprises (SME). In this paper an off-line programming environment for programming of industrial robots in the field of automated disassembly is presented. The exemplary implementation is realized at a pilot disassembly system, which was built up at the Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF) of the Technische Universität Berlin.

Kurzfassung Magnetische Flüssigkeiten sind stabile Suspensionen, in denen beschichtete magnetische oder magnetisierbare Teilchen in einer Trägerflüssigkeit dispergiert sind. Wenn der Durchmesser der Teilchen im Bereich weniger Nanometer ist, werden diese magnetischen Flüssigkeiten als Ferrofluide bezeichnet. Die Hauptanwendungsgebiete für Ferrofluide liegen in der diagnostischen und therapeutischen Medizin zur Tumorbehandlung und in technischen Systemen, wie zum Beispiel in Lautsprechern, Lagern oder Dämpfern, sowie in der Feinbearbeitung von Keramikkugeln. In diesem Artikel werden aktuelle Ergebnisse auf dem Gebiet der Positionierung mit magnetischen Flüssigkeiten dargestellt, die am Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF) der Technischen Universität Berlin an neuen Prototypen und mit neuen Ferrofluiden ermittelt wurden. Dabei werden die Unterschiede zwischen konventionellen magnetischen Flüssigkeiten mit Magnetitkolloiden und neuartigen Ferrofluiden auf der Basis von Kobaltkolloiden sowie zwischen den multifunktionalen Eigenschaften dieser Ferrofluide näher erörtert.

Air-stable Co, Fe, and Fe/Co nanoparticles are accessible by thermolysis of the metal carbonyl precursors in the presence of aluminium alkyls and subsequent "smooth oxidation". The structure of the particles was investigated by transmission electron microscopy (TEM, HRTEM), X-ray absorption spectroscopy (XAS), X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS), metastable impact electron spectroscopy (MIES), and small-angle neutron scattering (SANS). The peptization of the nanoparticles with suitable surfactants (oleic and lauric acid, sodium dioctylsulfosuccinate (AOT), LP-4 (a fatty acid condensation polymer), and KorantinSH (N-oleyl sarcosine)) yields magnetic fluids dispersed in carrier liquids such as toluene, kerosene, vacuum and mineral oils which are remarkably stable in air under ambient conditions. The resulting magnetic fluids show good magnetic properties. Several methods for the preparation of water-based MF are presented, e.g., formation of surfactant bilayers, using phase transfer agents, or surface modification with L-cysteine ethyl ester. Water-based metallic magnetic fluids have a high potential for a number of technical and biomedical applications. Technical applications of the Co-based ferrofluids in the field of positioning systems and magnetohydrostatic bearings were investigated. The results emphasize the scope of nanoparticulate ferrofluids having a metallic core.Keywords: Nanoparticles; Magnetic Fluids; Positioning Systems; Magnetohydrostatic Bearings Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.