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Author: Kraus, Tobias × End date: 2023 × End date: 2022 × Start date: 2022 × DDC: 620 ×

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Now showing 1 - 4 of 4
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    Dynamic Light Scattering on Nanoparticles in Microgravity in a Drop Tower
    (Heidelberg : Springer, 2022) Pyttlik, Andrea; Kuttich, Björn; Kraus, Tobias
    Gravity affects colloidal dispersions via sedimentation and convection. We used dynamic light scattering (DLS) to quantify the mobility of nanoparticles on ground and in microgravity. A DLS instrument was adapted to withstand the accelerations in a drop tower, and a liquid handling set-up was connected in order to stabilize the liquid temperature and enable rapid cooling or heating. Light scattering experiments were performed in the drop tower at ZARM (Bremen, Germany) during a microgravity interval of 9.1 s and compared to measurements on ground. Particle dynamics were analyzed at constant temperature and after a rapid temperature drop using a series of DLS measurements with 1 s integration time. We observed nanoparticles with average gold core diameters of 7.8 nm and non-polar oleylamine shells that were dispersed in tetradecane and had an average hydrodynamic diameter of 21 nm. The particles did not change their diameter in the observed temperature range. The particle dynamics inferred from DLS on ground and in microgravity were in good agreement, demonstrating the possibility to perform reliable DLS measurements in a drop tower.
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    Toward a Li-Ion Battery Ontology Covering Production and Material Structure
    (Weinheim [u.a.] : Wiley-VCH, 2022) Mutz, Marcel; Perovic, Milena; Gümbel, Philip; Steinbauer, Veit; Taranovskyy, Andriy; Li, Yunjie; Beran, Lisa; Käfer, Tobias; Dröder, Klaus; Knoblauch, Volker; Kwade, Arno; Presser, Volker; Werth, Dirk; Kraus, Tobias
    An ontology for the structured storage, retrieval, and analysis of data on lithium-ion battery materials and electrode-to-cell production is presented. It provides a logical structure that is mapped onto a digital architecture and used to visualize, correlate, and make predictions in battery production, research, and development. Materials and processes are specified using a predetermined terminology; a chain of unit processes (steps) connects raw materials and products (items) of battery cell production. The ontology enables the attachment of analytical methods (characterization methods) to items. Workshops and interviews with experts in battery materials and production processes are conducted to ensure that the structure is conformable both for industrial-scale and laboratory-scale data generation and implementation. Raw materials and intermediate products are identified and defined for all steps to the final battery cell. Steps and items are defined based on current standard materials and process chains using terms that are in common use. Alternative structures and the connection of the ontology to other existing ontologies are discussed. The contribution provides a pragmatic, accessible way to unify the storage of materials-oriented lithium-ion battery production data. It aids the linkage of such data with domain knowledge and the automation of data analysis in production and research.
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    Advancing environmental intelligence through novel approaches in soft bioinspired robotics and allied technologies: I-Seed project position paper for Environmental Intelligence in Europe
    (New York,NY,United States : Association for Computing Machinery, 2022) Mazzolai, Barbara; Kraus, Tobias; Pirrone, Nicola; Kooistra, Lammert; De Simone, Antonio; Cottin, Antoine; Margheri, Laura
    The EU-funded FET Proactive Environmental Intelligence project "I-Seed"(Grant Agreement n. 101017940, https://www.iseedproject.eu/) targets towards the development of a radically simplified and environmentally friendly approach for environmental monitoring. Specifically, I-Seed aims at developing a new generation of self-deployable and biodegradable soft miniaturized robots, inspired by the morphology and dispersion abilities of plant seeds, able to perform low-cost, environmentally responsible, in-situ measurements. The natural functional mechanisms of seeds dispersal offer a rich source of robust, highly adaptive, mass and energy efficient mechanisms, and behavioral and morphological intelligence, which can be selected and implemented for advanced, but simple, technological inventions. I-Seed robots are conceived as unique in their movement abilities because inspired by passive mechanisms and materials of natural seeds, and unique in their environmentally friendly design because made of all biodegradable components. Sensing is based on a chemical transduction mechanism in a stimulus-responsive sensor material with fluorescence-based optical readout, which can be read via one or more drones equipped with fluorescent LiDAR technology and a software able to perform a real time georeferencing of data. The I-Seed robotic ecosystem is envisioned to be used for collecting environmental data in-situ with high spatial and temporal resolution across large remote areas where no monitoring data are available, and thus for extending current environmental sensor frameworks and data analysis systems.
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    Microgravity Removes Reaction Limits from Nonpolar Nanoparticle Agglomeration
    (Weinheim : Wiley-VCH, 2022) Pyttlik, Andrea; Kuttich, Björn; Kraus, Tobias
    Gravity can affect the agglomeration of nanoparticles by changing convection and sedimentation. The temperature-induced agglomeration of hexadecanethiol-capped gold nanoparticles in microgravity (µ g) is studied at the ZARM (Center of Applied Space Technology and Microgravity) drop tower and compared to their agglomeration on the ground (1 g). Nonpolar nanoparticles with a hydrodynamic diameter of 13 nm are dispersed in tetradecane, rapidly cooled from 70 to 10 °C to induce agglomeration, and observed by dynamic light scattering at a time resolution of 1 s. The mean hydrodynamic diameters of the agglomerates formed after 8 s in microgravity are 3 times (for low initial concentrations) to 5 times (at high initial concentrations) larger than on the ground. The observations are consistent with an agglomeration process that is closer to the reaction limit on thground and closer to the diffusion limit in microgravity.