TY - CONF A1 - Ciornii, Dmitri A1 - Knigge, Xenia A1 - Radnik, Jörg A1 - Thünemann, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Altmann, Korinna T1 - Identification of toxicologically relevant functional groups on micro- and nanoplastic particles’ surface by means of X-Ray photoelectron spectroscopy N2 - Microplastic and nanoplastic particles (MNP) are spread all over the world in various types, shapes and sizes making it very challenging to accurately analyse them. Each sampling procedure, sample preparation method and detection technique needs suitable reference materials to validate the method for accurate results. Furthermore, the effects of these MNPs should be evaluated by risk and hazard assessment with test particles close to reality. To better understand MNP behavior and aid in clarification of their interactions with organisms, we produced several MNP materials by top-down procedure and characterized their properties. Since surface properties mostly determine particles’ toxicity, the aim of the present study was to determine which functional groups are present on MNPs and how the surface can be affected by the production process and particle’s environment. T2 - SETAC 34th Meeting CY - Seville, Spain DA - 05.05.2024 KW - Microplastics KW - Nanoplastics KW - Polypropylene KW - XPS KW - SEM PY - 2024 AN - OPUS4-60037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Hallier, Dorothea C. A1 - Smales, Glen Jacob A1 - Seitz, H. T1 - Extending Bio-SAXS measurements of Single-Stranded DNA-Binding Proteins: Radiation Protection of G5P by Cosolutes N2 - Small-angle X-ray scattering (SAXS) can be used for structural de- termination of biological macromolecules and polymers in their na- tive states. To improve the reliability of such experiments, the re- duction of radiation damage occurring from exposure to X-rays is needed.One method, is the use of scavenger molecules that protect macromolecules against radicals produced by radiation exposure.In this study we investigate the feasibility to apply the compatible solute, osmolyte and radiation protector Ectoine (THP(B)) as a scavenger throughout SAXS measurements of single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). Therefore we monitor the radiation induced changes of G5P during bio-SAXS. The resulting microscopic energy-damage relation was determined by particle scattering simu- lations with TOPAS/Geant4. The results are interpreted in terms of radical scavenging as well as post-irradiation effects, related to preferential-exclusion from the protein surface. Thus, Ectoine provides an non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies. T2 - MultiChem Conference 2023 CY - Prague, Czech Republic DA - 26.04.2023 KW - Bio-SAXS KW - BioSAXS KW - Compatible solute KW - Cosolute KW - DNA KW - Dosimetry KW - Ectoin KW - Ectoine KW - Ectoin KW - G5P KW - GVP KW - Geant4 KW - Geant4-DNA KW - Gene five protein KW - Hydroxyectoine KW - Ionizing radiation damage KW - LEE KW - McSAS3 KW - Microdosimetry KW - Monte-Carlo simulations KW - OH Radical KW - OH radical scavenger KW - Osmolyte KW - Particle scattering simulations KW - Protein KW - Protein unfolding KW - Proteins KW - ROS KW - Radiation damage KW - Radical Scavenger KW - Radical scavenger KW - SAXS KW - Single-stranded DNA-binding proteins KW - Small-angle xray scattering KW - Topas KW - Topas-MC KW - Topas-nBio KW - X-ray scattering KW - ssDNA KW - Median lethal energy deposit PY - 2023 AN - OPUS4-57407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Topolniak, Ievgeniia A1 - Hodoroaba, Vasile-Dan A1 - Braun, Ulrike A1 - Pfeifer, Dietmar A1 - Sturm, Heinz T1 - Reinforced UV curable cycloaliphatic epoxy oligosiloxane resin nanocomposite for coating applications N2 - Coating materials are nowadays often required to deliver not only sufficient barrier performance and suited optical appearance but a broad range of other functional properties. The incorporation of inorganic nanoparticles (NPs) is known to improve many key characteristics and provide new functionalities in polymer materials. Presented work aims to prepare and characterize an organic-inorganic coating material designed to bring together advantageous properties of hybrid materials and reinforcement effect delivered from the inorganic NPs embedment. Siloxane-based hybrid resins hold great advantages as coating materials as their properties can be tuned between those of polymers and those of glasses, thus, the compositions with superior thermal and mechanical properties can be achieved. We used Cycloaliphatic Epoxy Oligosiloxane (CEOS) resin as a polymeric matrix where the network formation was achieved by UV induced cationic polymerisation. Boehmite Alumina (BA) nanoparticles were added to CEOS resin as a reinforcing agent and resultant material was processed into films either by bar-coating or by spin-coating depending on further characterization procedure. Two different types of BA NPs, hydrophilic and organophilic, were used in order to assess the impact of particles surface on the resin characteristics. CEOS synthesis by condensation reaction was confirmed using 13C and 29Si NMR. Changes in CEOS photocuring process, resulting from particles incorporation, were monitored by real-time IR spectroscopy. At the same time, the thermal behaviour was evaluated by DSC and TGA methods. Morphology of the coatings was investigated by means of SEM operated in transmission mode. It was observed that BA presence increased the epoxy conversion degree and glass transition temperature. Material formulations providing best film characteristics were determined with regard to the particle type and loading. Compared to the hydrophilic nanoparticles, organophilic BA NPs yield superior overall performance of the foils. T2 - HYMA Conference CY - Sitges, Spain DA - 11.03.2019 KW - Cycloalyphatic epoxy oligosiloxane KW - Nanocomposite KW - Boehmite KW - Photocuring PY - 2019 AN - OPUS4-47641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria A1 - Prinz, Carsten A1 - Bienert, Ralf A1 - Wendt, Robert A1 - Kunkel, Benny A1 - Radnik, Jörg A1 - Hoell, Armin A1 - Wohlrab, Sebastian A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska T1 - Size-Tunable Ni-Cu Core-Shell Nanoparticles: Structure, Composition, and Catalytic Activity N2 - Nanoparticles (NPs) have become important materials for a variety of chemical technologies, including catalysis. One of the main challenges is the reduction of green house gases, such as CO2. One opportunity besides the capturing is the conversion to synthesis gas via the reverse water-gas shift reaction. A facile and efficient method is described for the solvothermal synthesis of size-tunable, stable, and uniform NiCu core-shell NPs. The diameter of the NPs can be tuned in a range from 6 nm to 30 nm and the Ni:Cu ratio from 30:1 to 1:1. The NPs are structurally characterized with combination of transmission electron microscopy, anomalous small-angle X-ray scattering, X-ray photoelectron spectroscopy, and X-ray absorption fine structure. Using these analytical methods, a core-shell-shell structure their chemical composition is elucidated. A depletion from the core to the shell is observed, with the core consisting of NiCu alloy, surrounded by an inner Ni-rich shell and an outer NiO shell. The SiO2-supported NiCu core-shell NPs show pronounced selectivity of >99% for CO in the catalytic reduction of CO2 to CO using hydrogen as reactant (reverse water–gas shift reaction). T2 - Nanoalloys: recent developments and future perspectives Faraday Discussion CY - London, UK DA - 21.09.2022 KW - Nanoparticles KW - Core-shell KW - Catalysis PY - 2022 AN - OPUS4-56831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Meyer, Susan A1 - Solomun, Tihomir A1 - Kunte, Hans-Jörg A1 - Sturm, Heinz T1 - Electron irradiation of biomolecules under physiological conditions: Experimental realization and microdosimetric calculations N2 - In the last years, secondary low-energy electrons (LEE) emerged as important, if not predominant, reductive pathway in ionizing damage of biomolecules. These electrons are created in copious amount as result of inelastic scattering of high energy radiation at water. Until now, all experiments the quantification of the effects of LEEs on the biomolecular damage was either performed in vacuum with LEE sources or with DNA on surfaces in humid atmosphere. We present a new experimental setup to irradiate biomolecules with electrons under physiological conditions. In combination with monte carlo simulations this setup makes it possible to determine microdosimetric quantities for biomolecules in liquid environment under electron irradiation. This opens up new possibilities in radiation research to access the LEE damage under well defined physiological condition, for more complex systems, such as DNA-Protein complexes and even living cells. T2 - 14th International Congress of the International Radiation Protection Association CY - Cape Town, South Africa DA - 09.05.2016 KW - DNA KW - Dosimetry KW - Microdosimetry KW - Geant4 KW - Low energy electrons KW - Radicals KW - Radiation damage KW - Polymers PY - 2016 AN - OPUS4-36399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maurer, G. A1 - Tuma, Dirk A1 - Chobanov, K. A1 - Kumełan, J. A1 - Pérez-Salado Kamps, Á. T1 - Gas solubility in ionic liquids: Solubility of a binary gas mixture in a pure ionic liquid as well as of a single gas in a binary liquid mixture N2 - Ionic Liquids (ILs) are employed in various fields, for example, reaction engineering (reactions with gases, such as hydroformylation (CO, H2), hydrogenation (H2), oxidation (O2)) or separation technology (separations of gases, reactants, and high-volatility reaction products). For the basic engineering of such processes, knowledge of phase equilibria, particularly of mixtures, over a broad (p,T) range is mandatory. This contribution reports on recent experimental results from our laboratory: – for the simultaneous solubility of a binary gas mixture in a pure ionic liquid – for the solubility of a single gas in a binary liquid solvent mixture. T2 - EUCHEM 2012 Conference on Molten Salts and Ionic Liquids CY - Celtic Manor, Wales, United Kingdom DA - 05.08.2012 KW - ionic liquids KW - gas solubility KW - Henry's constant PY - 2012 AN - OPUS4-35947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalies, G. A1 - Rockmann, R. A1 - Tuma, Dirk A1 - Arnrich, S. A1 - Bräuer, P. T1 - Reliable information on solids from liquid-Phase adsorption N2 - For the characterization of disperse and porous solids, usually single gas adsorption(GA) is employed. In the case of liquid adsorption (LA), the extraction of information on solids immediately becomes a more sophisticated matter since information on geometric as well energetic parameters of the solids is both superposed by liquid-mixture effects and displayed in excess terms. We have to ask if reliable solid parameters can be also obtained from LA isotherms. The enlarged data bank of gas and liquid adsorption measurements enables us to change systematically solid parameters (e.g., the pore width of MCM-41, the pore entrances of SBA-16, chemical heterogeneity) and to study in this way the influence of solid parameters on LA. T2 - The FOA 10, 10th International Conference on Fundamentals of Adsorption CY - Awaji Island, Japan DA - 23.05.2010 KW - porous solids KW - gas adsorption KW - excess isotherms PY - 2010 AN - OPUS4-35945 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barnefske, Lena A1 - Petersen, Andreas A1 - Heidmann, Gerd A1 - Sturm, Heinz T1 - Development of a self-healing silicone rubber for high-voltage cable accessories N2 - One of the biggest problems in high-voltage silicone rubber insulation cable accessories is the damage on electrical treeing, initiated by partial discharges. The electrical treeing starts at unavoidable imperfections inside the material or at interfaces. The damage is usually irreversible and leads around the starting points to a partial destruction of the material. To prolong the lifetime and thereby to increase the assurance of the structural component commonly, for mechanical improvement constituted filler is modified to obtain a self-healing silicone rubber. Damage mechanism is analysed to address the filler to the damage mode. T2 - DGP-Frühjahrstagung und EPS-CMD27 CY - Berlin, Germany DA - 11.03.2018 KW - Self-healing silicone rubber KW - HV cable accessories PY - 2018 AN - OPUS4-45333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barnefske, Lena A1 - Sturm, Heinz A1 - Arzt, Eduard T1 - Smart materials inspired by nature N2 - In the scope of the event two different smart materials inspired by nature were presented. On the one hand a self-healing material based on capsule based self-healing and on the other hand a micropatterned dry adhesive. T2 - Leibniz Young Polymer Scientist Forum CY - Aachen, Germany DA - 28.06.2018 KW - Self-healing KW - Smart materials KW - Micropatterned dry adhesive PY - 2018 AN - OPUS4-45334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin T1 - Temperature in micromagnetism: Cell size and scaling effects of the stochastic Landau-Lifshitz equation N2 - The movement of the macroscopic magnetic moment in ferromagnetic systems can be described by the Landau-Lifshitz (LL) or Landau-Lifshitz-Gilbert (LLG) equation. These equations are strictly valid only at absolute zero temperature. To include temperature effects a stochastic version of the LL or LLG equation for a spin density of one per unit cell can be used instead. To apply the stochastic LL to micromagnetic simulations, where the spin density per unit cell is generally higher, a conversion regarding simulation cell size and temperature has to be established. Based on energetic considerations, a conversion for ferromagnetic bulk and thin film systems is proposed. The conversion is tested in micromagnetic simulations which are performed with the Object Oriented Micromagnetic Framework (OOMMF). The Curie temperatures of bulk Nickel, Cobalt and Iron systems as well as Nickel thin-film systems with thicknesses between 6.3 mono layer (ML) and 31ML are determined from micromagnetic simulations. The results show a good agreement with experimentally determined Curie temperatures of bulk and thin film systems when temperature scaling is performed according to the presented model. T2 - EUROMAT 2019 CY - Stockholm, Sweden DA - 01.09.2019 KW - Magnetic nanoparticles KW - Stochastic Landau Lifshitz Gilbert equation KW - Magnetic moment KW - Landau Lifshitz equation KW - Exchange interaction KW - OOMMF KW - Object oriented micromagnetic framework KW - Temeprature scaling KW - LLG KW - Ferromagnetism KW - Micromagnetism PY - 2019 AN - OPUS4-48762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -