In: Physics and Chemistry of Minerals, 2014, vol. 41, no. 3, p. 197–214
The dehydroxylation reactions of chrysotile Mg₃Si₂O₅(OH)₄ and brucite Mg(OH)₂ were studied under inert nitrogen atmosphere using isothermal and non-isothermal approaches. The brucite decomposition was additionally studied under CO₂ in order to check the influence of a competing dehydroxylation/carbonation/decarbonisation reaction on the reaction kinetics. Isothermal experiments...
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In: American Mineralogist, 2013, vol. 98, no. 7, p. 1133–1145
One of the most important mechanisms releasing water in subducting slabs of oceanic crust is connected to the dehydration of serpentinized oceanic rocks. This study reports on a detailed investigation of the transition from chrysotile—an important serpentine mineral—to forsterite through the release of water.The dehydroxylation of natural chrysotile and the subsequent phase change to...
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In: Journal of Membrane Science, 2013, p. -
This paper presents the processing steps for producing thin planar and tubular oxygen separation membranes by thermoplastic forming of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) with polystyrene (PS) and stearic acid (SA) as binder. The influence of powder content on the shape stability of thin membranes (tubular and planar structures)...
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In: Journal of Materials Science, 2013, vol. 48, no. 7, p. 2934-2952
The aim of the present investigation is to define microstructure parameters, which control the effective transport properties in porous materials for energy technology. Recent improvements in 3D-imaging (FIB-nanotomography, synchrotron X-ray tomography) and image analysis (skeletonization and graph analysis, transport simulations) open new possibilities for the study of microstructure effects. In...
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In: AIChE Journal, 2013, vol. 59, no. 5, p. 1446–1457
The ion conductivity of two series of porous ceramic diaphragms impregnated with caustic potash was investigated by electrochemical impedance spectroscopy. To understand the impact of the pore structure on ion conductivity, the three-dimensional (3-D) pore geometry of the diaphragms was characterized with synchrotron x-ray absorption tomography. Ion migration was calculated based on an extended...
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In: American Mineralogist, 2012, vol. 97, no. 11-12, p. 1965-1976
A temperature-dependent in situ micro-FTIR and micro-Raman spectroscopic investigation was performed on powdered (FTIR, Raman) and single-crystal (Raman) lizardite-1T samples between room temperature and 819 °C. Between room temperature and 665 °C, the OH stretching bands shift to lower wavenumbers, demonstrating a weak expansion of the O3-H3…O2 interlayer distance. Band...
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In: Chemical Research in Toxicology, 2012, p. -
Ambient airborne particulate matter is known to cause various adverse health effects in humans. In a recent study on the environmental impacts of coal and tire combustion in a thermal power station fine crystals of PbSO4 (anglesite), ZnSO4•H2O (gunningite), and CaSO4 (anhydrite) were identified in the stack emissions. Here, we have studied the toxic potential of these sulfate phases as...
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In: ECS Electrochemistry Letters, 2012, vol. 1, no. 4, p. F25-F28
The alkaline electrolyzer industry is facing the imminent necessity of replacing the asbestos diaphragms with a separator made of a new environmentally friendly material. The influence of a diaphragm's material and porosity on the ionic conductivity was studied for asbestos, zirconium dioxide, wollastonite and olivine diaphragms. Developed electrochemical impedance spectroscopy (EIS) set-up with...
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In: Applied Energy, 2012, vol. 95, p. 147-155
Polymeric binder burnout during thermoplastic processing of yttria stabilized zirconia (YSZ) ceramics were analyzed using thermogravimetric analysis (TGA). The debinding kinetics of the stearic acid/polystyrene binder have been described using model free methods and compared with the decomposition rate of the pure polymers. The apparent activation energy Eα as a function of...
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In: European Journal of Mineralogy, 2012, vol. 24, no. 1, p. 47-57
The thermally induced dehydroxylation of lizardite and its phase transformation to forsterite were studied by high-temperature X-ray diffraction (HT-XRD), thermogravimetry (TGA) and Fourier-transformed infrared spectroscopy (FTIR). Primary sample characteristics like chemical composition and crystallographical structure were determined by combined (HR)TEM-EDX, electron-microprobe analyses...
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