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The wet chemical deposition of solution processed transparent conducting oxides (TCO) provides an alternative low cost and economical deposition technique to realize large-areas of conducting films. Since the price for the most common TCO Indium Tin Oxide rises enormously, Aluminum Zinc Oxide (AZO) as alternative TCO reaches more and more interest. The optoelectronical properties of nanoparticle coatings strongly depend beneath the porosity of the coating on the shape and size of the used particles. By using bigger or rod-shaped particles it is possible to minimize the amount of grain boundaries resulting in an improvement of the electrical properties, whereas particles bigger than 100 nm should not be used if highly transparent coatings are necessary as these big particles scatter the visible light and lower the transmittance of the coatings. In this work we present a simple method to synthesize AZO particles with different shape and size, but comparable electronical properties. We use a simple, well reproducible polyol method for synthesis and influence the shape and size of the particles by adding different amounts of water to the precursor solution. We can show that the addition of aluminum as dopant strongly hinders the crystal growth but the addition of water counteracts this, so that both, spherical and rod-shaped particles can be obtained.
Three established test methods employed for evaluating the abrasion or wear resistance of textile materials were compared to gain deeper insight into the specific damaging mechanisms to better understand a possible comparability of the results of the different tests. The knowledge of these mechanisms is necessary for a systematic development of finishing agents improving the wear resistance of textiles. Martindale, Schopper, and Einlehner tests were used to analyze two different fabrics made of natural (cotton) or synthetic (polyethylene terephthalate) fibers, respectively. Samples were investigated by digital microscopy and scanning electron microscopy to visualize the damage. Damage symptoms are compared and discussed with respect to differences in the damaging mechanisms.
Several ionic liquids are excellent solvents for cellulose. Starting from that finishing of PET fabrics with cellulose dissolved in ionic liquids like 1-ethyl 3-methyl imidazolium acetate, diethylphosphate and chloride, or the chloride of butyl-methyl imidazolium has been investigated. Finishing has been carried out from solutions of different concentrations, using microcrystalline cellulose or cotton and by employing different cross-linkers. Viscosity of solutions has been investigated for different ionic liquids,concentrations, cellulose sources, linkers and temperatures. Since ionic liquids exhibit no vapor pressure,simple pad-dry-cure processes are excluded. Before drying the ionic liquid has to be removed by a rinsing step. Accordingly rinsing with fresh ionic liquid followed by water or the direct rinsing with waterhave been tested. The amount of cellulose deposited has been investigated by gravimetry, zinc chlorideiodine test as well as reactive dyeing. Results concerning wettability, water up-take, surface resistance,wear-resistance or washing stability are presented.
Das textile Bauen ist ein seit vielen Jahren wachsender Bereich der Textilindustrie. Durch die Verwendung textiler Materialien bieten sich nicht zuletzt für die Architektur neue gestalterische Möglichkeiten, die mit konventionellen Baumaterialien nicht realisierbar sind. Bekannte Beispiele für textile Bauwerke sind große Sportarenen, Bahnhöfe und Flughäfen. Dabei sind Leichtbauweisen und zumindest teilweise Transparenz der Bauwerke auf einer Seite herausragende Eigenschaften, auf der anderen Seite stellen diese Gebäude besondere Anforderungen an das Klima- und Energiemanagement. Der Innenraum kann sich bei Sonneneinstrahlung stark aufheizen, da neben dem sichtbaren Licht vor allem ein Großteil des Infrarotanteils der solaren Strahlung transmittieren kann. Im konventionellen Bauen existieren bereits hohe Anforderungen an die energietechnische Ausgestaltung von Bauwerken, die u.a. über eine effiziente Wärmedämmung erfüllt werden. Dies wird in der Regel mit Hilfe von voluminösen, offenporigen Dämmstoffen erreicht. Ziel ist es dabei vornehmlich, den Verlust von Wärme aus dem Innenraum zu verringern, gleichzeitig können schlecht wärmeleitende Stoffe bei hoher Masse und hoher spezifischer Wärmekapazität Temperaturspitzen im Sommer abpuffern. Auch für das textile Bauen ist die Energieeffizienz ein wichtiger Aspekt. Die Verwendung von schweren Dämmstoffen widerspricht dabei aber der Idee der flexiblen textilen Leichtbauweise.