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End date: 2019 × Start date: 2019 × End date: 2009 × Start date: 2009 × DDC: 540 ×

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Now showing 1 - 8 of 8
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    Katalysierte selektive Oxidation von Alkylaromaten mit Sauerstoff und H2O2 als Oxidationsmittel (SelOx) : Abschlussbericht
    (Hannover : Technische Informationsbibliothek (TIB), 2009) Martin, Andreas
    [no abstract available]
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    Annual report 2008 // Institute of Radiochemistry
    (Dresden : Forschungszentrum Dresden-Rossendorf, 2009) Bernhard, Gert
    [no abstract available]
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    Transparent conductive oxides for coating applications
    (Saarbrücke : Leibniz-Institut für Neue Materialien, 2009) Quilitz, Mario; Oliveira, Peter W. de; Heusing, Sabine; Veith, Michael
    Transparent, conductive oxides (TCOs) applied as coatings find multiple applications in various areas such as flat panel display setups, as electrodes in touch-screen panels, electrochromic devices, solar cells and in architectural applications for example as IR reflectors. The favored material in the class of TCOs is still ITO - Sn-doped In2O3 - due to its unique combination of high transparency and electrical conductivity. Though already very good, the potential of the ITO coatings with regard to their conductivity leaves some space for future improvements. Also ITO as a material has some serious drawbacks, such as limited availability and high costs. this work presents some stratgies to overcome these obstacles. One way to enhance the conductivities of alternative materials is to use carbon nanotubes as a dopant. This strategy was tested for ATO (Antimony-doped Tin Oxide), Titan dioxide and AZO (Aluminium-doped Zinc oxide). The results for these materials are presented. In coatings of ITO on glass or polymeric foils usually silica-based binders are used. They have the disadvantage to reduce the contact between the highly conducting grains and thus reduce overall conductivity in the composite. The matrix between the nanoparticles can be improved by several measures. Experiments with relevance in this direction are discussed. A third strategy aims at the reduction of costs in the process of ITO fabrication. Here one way to go is to use an electrochemical synthesis method. Results of the line of development are presented. Other strategies comprise the suitable processing of materials with a lower intrinsic conductivity or the search for materials with high intrinsic conductivity close to that of ITO. Exmples are presented and discussed.
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    Large area production of optical coatings and devices by the sol-gel process
    (Saarbrücke : Leibniz-Institut für Neue Materialien, 2009) Oliveira, Peter; Quilitz, Mario; Heusing, Sabine; Lin, Hechun; Veith, Michael
    [no abstract available]
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    Research on the synthesis and applicability of surface modified nanoscaled metal oxide particles as curing catalyseres for UV-print-colours and lacquers
    (Saarbrücke : Leibniz-Institut für Neue Materialien, 2009) Becker-Willinger, Carsten; Schmitz-Stöwe, Sabine; Bentz, Dirk
    In the BMBF joint research project - NANOCURE - New Curing Methods for Print-Colours, Glues and Lacquers (prom. ref. : 13N9115) - a new class of nanoscaled photo initiators for radical polymerization processes in the printing industry is to be investigated. A possible mechanism for the reaction of TiO2 with acrylates, which is already described in literature is presented. Different methods of manufacturing TiO2 nanoparticles in the lower nanometric size range and their subsequent processing are described, the method is of special interest as it may lead to a possible integrated production process of UV-printing inks. The TEM analysis shows the homogeneous arrangement of TiO2 nanoparticles in an acrylic matrix, which is a necessary requirement for successful polymerization process. IR-spectroscopy is used to show the effect of TiO2-nanoparticles as UV photocatalytic polymerization initiators.
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    Translucent UV light absorbant coatings for wood
    (Saarbrücke : Leibniz-Institut für Neue Materialien, 2009) Ullrich, Alfred; Reinhard, Bernd; Wittmar, Matthias
    Efficient protection of fast growing domestic woods against the effects of weathering and UV irradiation is of increased significance to obtain improved dimensional stability and durability comparable to tropical wood. To advance the properties of those woods, a combined treatment process was developed. First, samples of pine sapwood were impregnated by project partners in the University of Göttingen to improve the dimensional stability and to avoid fungal infection of the wood, then a coating containig zinc oxide nanoparticles was applied on the impregnated wood samples at INM. Due to the UV light absorption of zinc oxide nanoparticles, the coated wood substrates are distinguished by enhanced colour stability. Together with the impregnation the coating prevents wood from deterioration by UV-irradiation and changing climates while retaining optical appearance. The water-repellent properties of the coatings interfered with the impregnation and reduced the ingress of water. This resulted in a stabilising reduction of the swelling and shrinking and avoided the formation of cracks in both wood and coating. The improved characteristics were demonstrated by artificial weathering. A prototype of an impregnated and coated window has been manufactured and is currently exposed to outdoor weathering.
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    Work on non photocatalytically active titania particles
    (Saarbrücke : Leibniz-Institut für Neue Materialien, 2009) Müller, Thomas S.; Faller-Schneider, Christine; Moh, Karsten; Shanmugasundaram, Sakthivel; Oliveira, Peter W. de; Veith, Michael
    Titanium dioxide has photocatalytic properties, i.e. under UV irradiation it develops an oxidative potential. In photocatalysis this is very desirable, but not when nano particulate titania is embedded into organic polymer matrices in order to increase the refractive index. UV irradiation would in this case destroy the material in the long run. For deactivation in general the titania is coated by e.g. silica or alumina which leads to other undesired effects like growth of the particle size and enhanced light scattering. The current work focuses on the application of techniques for doping during synthesis of crystallization of nano particulate TiO2. The photocatalysis activity was determined by degradation experiments of 4-chlorophenol using dip coated glass plates under artificial sunlight, where decreases of the photocatalytic effect of up to 90 % were found.
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    Functional surfaces for controlled adhesion
    (Saarbrücke : Leibniz-Institut für Neue Materialien, 2009) Arzt, Eduard; Del Campo, Aranzazu
    Adhesive joining with molecular (van der Waals) interactions without chemical glue is presently receiving much attention because of many potential applications. Research on how insects, spiders and geckos stick to surfaces has inspired a new paradigm: fibrillar surfaces with appropriate design can show much higher adhesion performance than flat surfaces. The insight gained in studying biological systems can be transferred to the development of optimized artificial attachment devices. By systematic variations of fiber diameter, aspect ratio and contact shape, we have produced, on a laboratory scale, artificial structures with adhesion strengths similar to the gecko. Further advances with switchable adhesion ("smart adhesives") have been demonstrated and may lead to interesting applications in medical products, sports equipment, construction materials and microfabrication.