Publications by authors named "Urs Peuker"

Dry particle coating processes are of key importance for creating functionalized materials. By a change in surface structure, initiated during coating, a surface property change and thus functionalization can be achieved. This study introduces an innovative approach employing 3D X-ray micro-computed tomography (micro-CT) to characterize coated particles, consisting of spherical alumina particles (d50 = 45.

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There are various possibilities for changing the surface properties of particles. In this work, the charge reversal on different metal oxides with different electrolytes is investigated and whether this allows a change in wettability due to a subsequent adsorption of surfactants, e.g.

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The dynamics of the three-phase contact line during particle-bubble interactions determine the stability of particle-bubble aggregates in flotation. The interaction of particles and sessile gas bubbles can be studied by colloidal probe atomic force microscopy (CP-AFM). This paper demonstrates a method to obtain the contact angle, the position of the three-phase contact line on the particle, and the bubble profile by utilizing the full information contained in AFM force-distance curves, i.

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Prior to the mechanical processing, discharging is necessary to prevent hazards. While the discharging process, different phenomena can occur changing the characteristics of the functional units of LIB. This study reveals the influence on the mechanical recycling and the obtained material when different discharge levels are used for various cells differing in their cell chemistry.

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With the increasing number of electrical devices, especially electric vehicles, the need for efficient recycling processes of electric components is on the rise. Mechanical recycling of lithium-ion batteries includes the comminution of the electrodes and sorting the particle mixtures to achieve the highest possible purities of the individual material components (e.g.

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A drying droplet containing colloidal particles can consolidate into a spherical assembly called a supraparticle. Such supraparticles are inherently porous due to the spaces between the constituent primary particles. Here, the emergent, hierarchical porosity in spray-dried supraparticles is tailored via three distinct strategies acting at different length scales.

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Herein we report on an analytical study of dry-shredded lithium-ion battery (LIB) materials with unknown composition. Samples from an industrial recycling process were analyzed concerning the elemental composition and (organic) compound speciation. Deep understanding of the base material for LIB recycling was obtained by identification and analysis of transition metal stoichiometry, current collector metals, base electrolyte and electrolyte additive residues, aging marker molecules and polymer binder fingerprints.

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In the present paper, as part of an interdisciplinary research project (Priority Programme SPP2045), we propose a possible way to design an open access archive for particle-discrete tomographic datasets: the PARROT database (https://parrot.tu-freiberg.de).

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The use and development of lithium-ion batteries (LIBs) are promoting the technological transformation of individual mobility, consumer electronics and electric energy storage. At their end of life, the complex compounds are disposed by different recycling technologies with defined secondary raw material production. The applied depollution temperatures of the process routes influence not only the recycling efficiency but also the process expenditure, design, medium and costs.

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Variable interfacial tension could be desirable for many applications. Beyond classical stimuli like temperature, we introduce an electrochemical approach employing polymers. Hence, aqueous solutions of the nonionic-cationic block copolymer poly(ethylene oxide)--poly{[2-(methacryloyloxy)ethyl]diisopropylmethylammonium chloride} (i.

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The three-dimensional characterization of distributed particle properties in the micro- and nanometer range is essential to describe and understand highly specific separation processes in terms of selectivity and yield. Both performance measures play a decisive role in the development and improvement of modern functional materials. In this study, we mixed spherical glass particles (0.

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Data presented in this article focus on the application of steam pressure filtration in combination with a water insoluble pore liquid. The article describes measured temperature profiles during steam pressure filtration within a filter cake. This article is co-submitted to the article 'Steam Pressure Filtration in Combination with a Water Insoluble Pore Liquid' [1] (DOI: 10.

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In X-ray microtomography the sample has to meet special requirements regarding (1) mechanical stability (blurring), (2) geometry (FOV - field of view, rotational symmetry) and (3) composition (high attenuating phases). When analyzing micron-sized particulate material (e.g.

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In this paper, prediction models are proposed which allow the mineralogical characterization of particle systems observed by X-ray micro tomography (XMT). The models are calibrated using 2D image data obtained by a combination of scanning electron microscopy and energy dispersive X-ray spectroscopy in a planar cross-section of the XMT data. To reliably distinguish between different minerals the models are based on multidimensional distributions of certain particle characteristics describing, for example, their size, shape, and texture.

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The number of electric and hybrid electric vehicles (EVs and HEVs) as an alternative to internal combustion engines (ICE) has been rapidly growing for the last five years. When the electric cars or their traction batteries reach their end of life (EOL), an efficient recycling (from a material as well as an energetic point of view) is important to ensure sustainability and to close the materials cycle. Combining mechanical processes like crushing, screening and sorting, valuable metals such as copper, steel and aluminium can be recovered.

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In this paper, three-dimensional (3D) image data of ore particle systems is investigated. By combining X-ray microtomography with scanning electron microscope (SEM)-based image analysis, additional information about the mineralogical composition from certain planar sections can be gained. For the analysis of tomographic images of particle systems the extraction of single particles is essential.

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A method for the determination of interactions between yeast cells and air bubbles using the atomic force microscope was developed, in which a bubble acts as probe on immobilised living cells. The experimental setup and influencing parameters like bubble size, dwell time and maximum contact force on force-distance curves and maximum adhesion forces are explained. Also, interactions between bubble and yeast cells under variation of pH, ethanol concentration, salt concentration, ionic strength and influence of storage time in Yeast Malt Broth and phosphate buffered saline are investigated and discussed.

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This experimental study deals with the colloidal stability of sterically functionalized magnetite nanoparticles in a low dielectric constant organic solvent with different concentrations of technical grade polymers. Those dispersions are the starting point of a solution and spray drying process chain to synthesize highly filled nanocomposite materials with nanoparticle volume concentrations exceeding 10%. We introduce a thermo gravimetric method together with light extinction and dynamic light scattering measurements to gain quantitative information on the concentration of primary particles and the mechanism of destabilization or stabilization by polymer addition.

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Downstream processing is a major issue in biotechnological production. A multitude of unit operations with nonsatisfying yield are often used to reach the desired product purity. Direct recovery technologies such as high-gradient magnetic fishing (HGMF) are advantageous because of their ability to separate the desired product in early stages from crude cultivation broths.

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In this study we describe the synthesis and characterization of nanocation exchanger particles (NCEX) as the functional filling material for magnetic beads. Polystyrene NCEX particles were synthesized from styrene via a mini-emulsion polymerization. The coupling of cation exchanger groups was done with chlorosulfuric acid after the polymerization reaction.

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