TY - JOUR A1 - Junge, Florian A1 - Wittwer, Philipp A1 - Sommerfeld, Thomas A1 - Gehrenkemper, Lennart A1 - Zoister, Christian A1 - Nickl, Philip A1 - Koch, Matthias A1 - Meermann, Björn A1 - Haag, Rainer T1 - Adsorber Charge Dominates over Hydrophobic or Fluorophilic Functionalization in Influencing Adsorption of PFCA onto Polystyrene Resins N2 - A systematic series of industrial-relevant polystyrene-based anion exchange resins that are functionalized with hydro- or fluorocarbon chains are compared regarding their adsorption behavior toward perfluorocarboxylic acids (PFCA) in respect to their charge, chain length, and type of chain. The results clearly show the dominance of electrostatic interactions in the adsorption process as uncharged adsorber materials showed no adsorption at all. In contrast, the charged adsorber materials showed in general a PFCA removal of 80% to 30% over the experiment depending on effluent fraction. Unexpectedly, for perfluorobutanoic acid (PFBA) the highest removal rate is found with consistently >90%. Despite observing significant benefits in the adsorption of PFCA for fluoroalkylated adsorbers in comparison to their non-fluorinated counterparts, this effect of fluoroalkylation is comparatively small and can not be clearly attributed to fluorophilic interactions between the fluoroalkyl chains. These findings help clarifying that the introduction of fluorocarbon moieties in adsorber materials is not necessary in order to remove fluorocarbon molecules from the environment. KW - PFAS KW - Remediation KW - Adsorption KW - Fluorophilic interactions PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601883 DO - https://doi.org/10.1002/admi.202400199 SN - 2196-7350 SP - 1 EP - 10 PB - John Wiley & Sons CY - Hoboken, New Jersey, USA AN - OPUS4-60188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tabaka, Weronika A1 - Meinel, Dietmar A1 - Schartel, Bernhard T1 - Sacrifice Few to Save Many: Fire Protective Interlayers in Carbon- Fiber-Reinforced Laminates N2 - The fire protection of carbon-fiber-reinforced polymer (CFRP) laminates often relies on flame-retardant coatings, but in some applications, their efficacy may diminish upon direct fire exposure due to rapid pyrolysis. This study introduces an innovative approach by integrating protective interlayers within the laminate structure to enhance the fire resistance. Various materials, including ceramic composite WHIPOX, titanium foil, poly(etherimide) (PEI) foil, basalt fibers, rubber mat, and hemp fibers, were selected as protective interlayers. These interlayers were strategically placed within the laminate layout to form a sacrificial barrier, safeguarding the integrity of the composite. Bench-scale fire resistance tests were conducted, where fire (180 kW/m2) was applied directly to the one side of the specimen by a burner while a compressive load was applied at the same time. Results indicate significant prolongation of time to failure for CFRP laminates with protective interlayers, which is up to 10 times longer. This innovative approach represents a potential advance in fire protection strategies for CFRP laminates, offering improved resilience against fire-induced structural failure. KW - Composites in fire KW - Fire resistance KW - Fire retardant interlayers KW - Laminate design KW - Carbon fibre reinforced PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601943 DO - https://doi.org/10.1021/acsomega.4c01408 SN - 2470-1343 VL - 9 IS - 22 SP - 23703 EP - 23712 PB - ACS AN - OPUS4-60194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Leonhardt, Robert A1 - Böttcher, Nils A1 - Dayani, Shahab A1 - Rieck, Arielle A1 - Markötter, Henning A1 - Schmidt, Anita A1 - Kowal, Julia A1 - Tichter, Tim A1 - Krug von Nidda, Jonas T1 - Exploring the electrochemical and physical stability of lithium-ion cells exposed to liquid nitrogen N2 - The transport and storage of lithium-ion (Li-ion) batteries — damaged or in an undefined state — is a major safety concern for regulatory institutions, transportation companies, and manufacturers. Since (electro)chemical reactivity is exponentially temperature-dependent, cooling such batteries is an obvious measure for increasing their safety. The present study explores the effect of cryogenic freezing on the electrochemical and physical stability of Li-ion cells. For this purpose, three different types of cells were repeatedly exposed to liquid nitrogen (LN2). Before and after each cooling cycle, electrical and electrochemical measurements were conducted to assess the impact of the individual freezing steps. While the electrochemical behavior of the cells did not change significantly upon exposure to LN2 , it became apparent that a non-negligible number of cells suffered from physical changes (swelling) and functional failures. The latter defect was found to be caused by the current interrupt device of the cylindrical cells. This safety mechanism is triggered by the overpressure of expanding nitrogen which enters the cells at cryogenic temperatures. This study underlines that the widely accepted reversibility of LN2 -cooling on a material scale does not allow for a direct extrapolation toward the physical integrity of full cells. Since nitrogen enters the cell at cryogenic temperatures and expands upon rethermalization, it can cause an internal overpressure. This can, in turn, lead to mechanical damage to the cell. Consequently, a more appropriate temperature condition — less extreme than direct LN2 exposure — needs to be found KW - Lithium-ion battery KW - LN2 cooling KW - Battery characterization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599248 DO - https://doi.org/10.1016/j.est.2024.111650 VL - 89 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-59924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, Heike A1 - Knigge, Xenia A1 - Knapic, D. A1 - Weise, Matthias A1 - Sahre, Mario A1 - Hertwig, Andreas A1 - Sacco, A. A1 - Rossi, A. M. A1 - Radnik, Jörg A1 - Müller, Kai A1 - Wasmuth, Karsten A1 - Krüger, Jörg A1 - Hassel, A. W. A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Picosecond laser processing of hierarchical micro–nanostructures on titanium alloy upon pre- and postanodization: morphological, structural, and chemical effects N2 - Recent publications indicate that the order of electrochemical anodization (before or after the laser processing step) plays an important role for the response of bone-forming osteoblasts—an effect that can be utilized for improving permanent dental or removable bone implants. For exploring these different surface functionalities, multimethod morphological, structural, and chemical characterizations are performed in combination with electrochemical pre- and postanodization for two different characteristic microspikes covered by nanometric laser-induced periodic surface structures on Ti–6Al–4V upon irradiation with near-infrared ps-laser pulses (1030 nm wavelength, ≈1 ps pulse duration, 67 and 80 kHz pulse repetition frequency) at two distinct sets of laser fluence and beam scanning parameters. This work involves morphological and topographical investigations by scanning electron microscopy and white light interference microscopy, structural material examinations via X-ray diffraction, and micro-Raman spectroscopy, as well as near-surface chemical analyses by X-ray photoelectron spectroscopy and hard X-ray photoelectron spectroscopy. The results allow to qualify the mean laser ablation depth, assess the spike geometry and surface roughness parameters, and provide new detailed insights into the near-surface oxidation that may affect the different cell growth behavior for pre- or postanodized medical implants. T2 - 2023 E-MRS Spring Meeting, Symposium L "Making light matter: lasers in material sciences and photonics" CY - Strasbourg, France DA - 29.05.2023 KW - Hierarchical micro-nanostructures KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Ti-6Al-4V alloy KW - X-ray photoelectron spectroscopy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601962 DO - https://doi.org/10.1002/pssa.202300920 SN - 1862-6319 SP - 1 EP - 11 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-60196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chen, Z. A1 - Perez, J. P. H. A1 - Smales, Glen Jacob A1 - Blukis, R. A1 - Pauw, Brian Richard A1 - Stammeier, J. A. A1 - Radnik, Jörg A1 - Smith, A. J. A1 - Benning, L. G. T1 - Impact of organic phosphates on the structure and composition of short-range ordered iron nanophases N2 - Organic phosphates (OP) are important nutrient components for living cells in natural environments, where they readily interact with ubiquitous iron phases such as hydrous ferric oxide, ferrihydrite (FHY). FHY partakes in many key bio(geo)chemical reactions including iron-mediated carbon storage in soils, or iron-storage in living organisms. However, it is still unknown how OP affects the formation, structure and properties of FHY. Here, we document how β-glycerophosphate (GP), a model OP ligand, affects the structure and properties of GP–FHY nanoparticles synthesized by coprecipitation at variable nominal molar P/Fe ratios (0.01 to 0.5). All GP–FHY precipitates were characterized by a maximum solid P/Fe ratio of 0.22, irrespective of the nominal P/Fe ratio. With increasing nominal P/Fe ratio, the specific surface area of the GP–FHY precipitates decreased sharply from 290 to 3 m2 g−1, accompanied by the collapse of their pore structure. The Fe–P local bonding environment gradually transitioned from a bidentate binuclear geometry at low P/Fe ratios to monodentate mononuclear geometry at high P/Fe ratios. This transition was accompanied by a decrease in coordination number of edge-sharing Fe polyhedra, and the loss of the corner-sharing Fe polyhedra. We show that Fe(III) polymerization is impeded by GP, and that the GP–FHY structure is highly dependent on the P/Fe ratio. We discuss the role that natural OP-bearing Fe(III) nanophases have in biogeochemical reactions between Fe–P and C species in aquatic systems. KW - Organic phosphates KW - Iron nanophases KW - Scattering KW - Diffraction KW - Nanomaterials KW - Coprecipitation KW - Carbon storage PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599399 DO - https://doi.org/10.1039/d3na01045g SN - 2516-0230 SP - 1 EP - 13 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-59939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sordello, F. A1 - Prozzi, M. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg A1 - Pellegrino, F. T1 - Increasing the HER efficiency of photodeposited metal nanoparticles over TiO2 using controlled periodic illumination N2 - Although the use of noble metal catalysts can increase the efficiency of hydrogen evolution reaction, the process is still limited by the characteristics of the metal-hydrogen (M−H) bond, which can be too strong or too weak, depending on the metal employed. Studies revealed that the hydrogen affinity for the metal surface (i.e. H absorption/desorption) is regulated also by the potential at the metal nanoparticles. Through controlled periodic illumination (CPI) of a series of metal/TiO2 suspensions, here we demonstrated that an increase of the HER efficiency is possible for those photodeposited metals which have a Tafel slope below 125 mV. Two possible explanations are here reported, in both of them the M−H interaction and the metal covering level play a prominent role, which also depend on the prevailing HER mechanism (Volmer-Heyrovsky or Volmer-Tafel). KW - Controlled periodic illumination KW - Hydrogen evolution reaction KW - Titanium dioxide KW - Photoreforming KW - Volcano plot KW - Sabatier KW - Nanoparticles PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589875 DO - https://doi.org/10.1016/j.jcat.2023.115215 VL - 429 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-58987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elert, Anna Maria A1 - Chen, Yong-Cin A1 - Smales, Glen J. A1 - Topolniak, Ievgeniia A1 - Sturm, Heinz A1 - Schönhals, Andreas A1 - Szymoniak, Paulina T1 - Effects of the charge density of nanopapers based on carboxymethylated cellulose nanofibrils investigated by complementary techniques N2 - Cellulose nanofibrils (CNFs) with different charge densities were prepared and investigated by a combination of different complementary techniques sensitive to the structure and molecular dynamics of the system. The morphology of the materials was investigated by scanning electron microscopy (SEM) and X-ray scattering (SAXS/WAXS). The latter measurements were quantitatively analyzed yielding to molecular parameters in dependence of the charge density like the diameter of the fibrils, the distance between the fibrils, and the dimension of bundles of nanofibrils, including pores. The influence of water on the properties and the charge density is studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and broadband dielectric spectroscopy. The TGA measurements reveal two mass loss processes. The one at lower temperatures was related to the loss of water, and the second process at higher temperatures was related to the chemical decomposition. The resulting char yield could be correlated to the distance between the microfibrils. The DSC investigation for hydrated CNFs revealed three glass transitions due to the cellulose segments surrounded by water molecules in different states. In the second heating scan, only one broad glass transition is observed. The dielectric spectra reveal two relaxation processes. At low temperatures or higher frequencies, the β-relaxation is observed, which is assigned to localized fluctuation of the glycosidic linkage. At higher temperatures and lower frequencies, the α-relaxation takes places. This relaxation is due to cooperative fluctuations in the cellulose segments. Both processes were quantitatively analyzed. The obtained parameters such as the relaxation rates were related to both the morphological data, the charge density, and the content of water for the first time. KW - Cellulose nanofibrils PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600528 DO - https://doi.org/https://doi.org/10.1021/acsomega.4c00255 SN - 2470-1343 VL - 9 SP - 20152 EP - 20166 PB - ACS AN - OPUS4-60052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silbernagl, Dorothee A1 - Szymoniak, Paulina A1 - Tavasolyzadeh, Zeynab A1 - Sturm, Heinz A1 - Topolniak, Ievgeniia T1 - Multiphoton Lithography of Interpenetrating Polymer Networks for Tailored Microstructure Thermal and Micromechanical Properties N2 - Multiphoton lithography (MPL), an emerging truly 3D microfabrication technique, exhibits substantial potential in biomedical applications, including drug delivery and tissue engineering. Fabricated micro-objects are often expected to undergo shape morphing or bending of the entire structure or its parts. Furthermore, ensuring precise property tuning is detrimental to the realization of the functionality of MPL microstructures. Herein, novel MPL materials based on interpenetrating polymer networks (IPNs) are presented that effectively combine the advantages of acrylate and epoxy systems. IPNs with varying component ratios are investigated for their microfabrication performance and structural integrity with respect to thermal and micromechanical properties. A variety of high-resolution techniques is applied to comprehensively evaluate IPN properties at the bulk, micron, and segmental levels. This study shows that the MPL laser scanning velocity and power, photoinitiator content, and multi-step exposure can be used to tune the morphology and properties of the IPN. As a result, a library of 3D MPL IPN microstructures with high 3D structural stability and tailored thermal and micromechanical properties is achieved. New IPN microstructures with Young’s moduli of 3–4 MPa demonstrate high-to-fully elastic responses to deformations, making them promising for applications in morphable microsystems, soft micro-robotics, and cell engineering. KW - Interpenetrating polymer network KW - Multiphoton lithography KW - Atomic force microscopy KW - Intermodulation AFM KW - Fast scanning calorimetry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600593 DO - https://doi.org/10.1002/smll.202310580 SN - 1613-6810 SP - 1 EP - 12 PB - Wiley VHC-Verlag AN - OPUS4-60059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hirsch, Philipp Daniel A1 - Kunji Purayil, Sruthi Krishna A1 - Lecompagnon, Julien A1 - Hassenstein, Christian A1 - Ziegler, Mathias T1 - Robotergestützte 3D-Scans und Laserthermografie zur Prüfung an komplexen Bauteilen auf Risse N2 - Die Integration von Automation und Robotik in die Prüfprozesse ermöglicht die Untersuchung komplexer Bauteile. Diese Studie präsentiert die robotergestützte Laserthermografie, um Risse in solchen Bauteilen zu identifizieren und analysieren. Diese Technik ermöglicht die automatisierte Rissprüfung welche im Vergleich zur Farbeindringprüfung auf viele, meist manuelle, Arbeitsschritte sowie die notwendigen Chemikalien verzichtet. Zusätzlich wird ein automatisiertes Einscannen der Bauteile mithilfe eines Linienscanners vorgestellt. Dieser Schritt ermöglicht eine detaillierte 3D-Rekonstruktion der Bauteilgeometrie und ermöglicht eine einfache Korrektur von Abweichungen in der Bauteilaufnahme und eröffnet Möglichkeiten zur adaptiven Bahnplanung bei Bauteilverformungen. Die Rückprojektion der gefundenen Risse auf die Oberfläche des Bauteils kann automatisiert erfolgen. Dieser Schritt erlaubt nicht nur die Identifikation der Risse, sondern auch eine genauere Analyse ihrer Geometrie und Lage am Bauteil. Die Kombination von robotergestützter Laserthermografie, automatisiertem 3DScanning und Rückprojektion der Risse auf die Bauteiloberfläche eröffnet neue Möglichkeiten in der zerstörungsfreien Prüfung von komplexen Bauteilen und erweitert damit mögliche Anwendungsfelder. T2 - Jahrestagung der Deutschen Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) 2024 CY - Osnabrück, Germany DA - 06.05.2024 KW - ZFP4.0 KW - Automatisierung KW - Thermografie KW - Laser KW - Roboter PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604811 UR - https://www.ndt.net/?id=29520 VL - 182 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60481 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - You, Zengchao A1 - Winckelmann, Alexander A1 - Vogl, Jochen A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique T1 - Determination of calcium, iron, and selenium in human serum by isotope dilution analysis using nitrogen microwave inductively coupled atmospheric pressure plasma mass spectrometry (MICAP-MS) N2 - In this study, we demonstrate the applicability of nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS) for Ca, Fe, and Se quantification in human serum using isotope dilution (ID) analysis. The matrix tolerance of MICAP-MS in Na matrix was investigated, uncovering that high Na levels can suppress the signal intensity. This suppression is likely due to the plasma loading and the space charge effect. Moreover, 40Ca and 44Ca isotopic fractionation was noted at elevated Na concentration. Nine certified serum samples were analyzed using both external calibration and ID analysis. Overestimation of Cr, Zn, As, and Se was found in the results of external calibration, which might be resulted from C-induced polyatomic interference and signal enhancement, respectively. Further investigations performed with methanol showed a similar enhancement effect for Zn, As, and Se, potentially supporting this assumption. The mass concentrations determined with ID analysis show metrological compatibility with the reference values, indicating that MICAP-MS combined with ID analysis can be a promising method for precise Ca, Fe, and Se determination. Moreover, this combination reduces the influences of matrix effects, broadening the applicability of MICAP-MS for samples with complex matrix. KW - Selenium KW - Nitrogen microwave inductively coupled atmospheric pressure mass spectrometry KW - Isotope dilution KW - Human serum KW - Calcium KW - Iron PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598664 DO - https://doi.org/10.1007/s00216-024-05274-0 SN - 1618-2642 SP - 3117 EP - 3125 PB - Springer CY - Berlin AN - OPUS4-59866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cakir, Cafer Tufan A1 - Bogoclu, Can A1 - Emmerling, Franziska A1 - Streli, Christina A1 - Guilherme Buzanich, Ana A1 - Radtke, Martin T1 - Machine learning for efficient grazing-exit x-ray absorption near edge structure spectroscopy analysis: Bayesian optimization approach N2 - In materials science, traditional techniques for analyzing layered structures are essential for obtaining information about local structure, electronic properties and chemical states. While valuable, these methods often require high vacuum environments and have limited depth profiling capabilities. The grazing exit x-ray absorption near-edge structure (GE-XANES) technique addresses these limitations by providing depth-resolved insight at ambient conditions, facilitating in situ material analysis without special sample preparation. However, GE-XANES is limited by long data acquisition times, which hinders its practicality for various applications. To overcome this, we have incorporated Bayesian optimization (BO) into the GE-XANES data acquisition process. This innovative approach potentially reduces measurement time by a factor of 50. We have used a standard GE-XANES experiment, which serve as reference, to validate the effectiveness and accuracy of the BO-informed experimental setup. Our results show that this optimized approach maintains data quality while significantly improving efficiency, making GE-XANES more accessible to a wider range of materials science applications. KW - Machine Learning KW - GE-XANES KW - Bayesian Optimization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603955 DO - https://doi.org/10.1088/2632-2153/ad4253 VL - 5 IS - 2 SP - 1 EP - 12 PB - IOP Publishing AN - OPUS4-60395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lapenna, Michela A1 - Tsamos, Athanasios A1 - Faglioni, Francesco A1 - Fioresi, Rita A1 - Zanchetta, Ferdinando A1 - Bruno, Giovanni T1 - Geometric deep learning for enhanced quantitative analysis of microstructures in X-ray computed tomography data N2 - Quantitative microstructural analysis of XCT 3D images is key for quality assurance of materials and components. In this paper we implement a Graph Convolutional Neural Network (GCNN) architecture to segment a complex Al-Si Metal Matrix composite XCT volume (3D image). We train the model on a synthetic dataset and we assess its performance on both synthetic and experimental, manually-labeled, datasets. Our simple GCNN shows a comparable performance, measured via the Dice score, to more standard machine learning methods, but uses a greatly reduced number of parameters (less than 1/10 of parameters), features low training time, and needs little hardware resources. Our GCNN thus achieves a cost-effective reliable segmentation. KW - Geometric deep learning KW - Segmentation KW - Microstructure KW - X-ray computed tomography KW - Al–Si metal matrix composites PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602517 DO - https://doi.org/10.1007/s42452-024-05985-0 SN - 3004-9261 VL - 6 IS - 6 SP - 1 EP - 9 AN - OPUS4-60251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tatzel, Michael A1 - Oelze, Marcus A1 - Frick, Daniel A. A1 - Di Rocco, Tommaso A1 - Liesegang, Moritz A1 - Stuff, Maria A1 - Wiedenbeck, Michael T1 - Silicon and oxygen isotope fractionation in a silicified carbonate rock N2 - Silicon isotope fractionation during silicification is poorly understood and impedes our ability to decipher paleoenvironmental conditions from Si isotopes in ancient cherts. To investigate isotope fractionation during silica-for-carbonate replacement we analyzed the microscale Si and O isotope composition in different silica phases in a silicified zebra dolostone as well as their bulk δ18O and Δ’17O compositions. The subsequent replacement of carbonate layers is mimicked by decreasing δ18O and δ30Si. The textural relationship and magnitude of Si and O isotope fractionation is best explained by near-quantitative silica precipitation in an open system with finite Si. A Rayleigh model for silicification suggests positive Ɛ30/28Si during silicification, conforming with predictions for isotope distribution at chemical equilibrium from ab-initio models. Application of the modelled Ɛ30Si-T relationship yields silicification temperatures of approx. 50°C. To reconcile the δ18Ochert composition with these temperatures, the δ18O of the fluid must have been between -2.5 and -4 ‰, compositions for which the quartz phases fall close to the oxygen equilibrium fractionation line in three-isotope space. Diagenetic silica replacement appears to occur in O and Si isotopic equilibrium allowing reconstructions of temperatures of silicification from Si isotopes and derive the δ18O composition of the fluid – a highly desired value needed for accurate reconstructions of the temperature- and δ18O histories of the oceans. KW - Silicon isotopes PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603430 DO - https://doi.org/10.1016/j.chemgeo.2024.122120 SN - 0009-2541 VL - 658 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-60343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Häßler, Dustin A1 - Mund, Maximilian A1 - Daus, Lars-Hendrik A1 - Hothan, Sascha A1 - Schaumann, Peter A1 - Schartel, Bernhard T1 - Durability of intumescent coatings and recommendations for test concepts for a working life of more than 10 years N2 - It is an essential requirement for all building products to ensure durability of their fire safety. Throughout the working life of products, intumescent coatings are aged by certain climatic factors. To predict a lifetime of several years, generally the behaviour of the intumescent coating is extrapolated based on accelerated artificial ageing. The established German and European procedures to assess the durability assume a working life of at least 10 years. For a longer period, additional evidence is required; yet the procedure and the specifications to justify this are not described. In addition to addressing this formal lack, from a scientific point of view it is necessary to investigate the degradation of intumescent coatings in detail and to propose a reliable test concept to assess durability for more than 10 years. This paper summarises the existing knowledge about the ageing of intumescent coatings. The results of various demanding weathering approaches are presented for two intumescent coatings tested in a joint research project. Moreover, formulations with a reduced amount of functionally relevant components were analysed to gain insight into the associated effects. Derived from these research results and knowledge, recommendations are proposed to assess the durability of intumescent coatings for more than 10 years based on a combination of verifications. KW - Ageing KW - Fire protection KW - Intumescent coating KW - Steel construction KW - Working life PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603852 DO - https://doi.org/10.1016/j.firesaf.2024.104173 SN - 0379-7112 VL - 146 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-60385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schuberth, Jens A1 - Ebert, Thomas A1 - Schlegel, Moritz-Caspar A1 - Rödig, Lisa A1 - Jepsen, Dirk A1 - Memelink, Robin A1 - Hauschke, Fynn T1 - The Front-Runner Approach - Facilitating Progressive Product Policy by Using Information from EU Product Databases N2 - The European Commission has recently announced two guiding principles for EU product policy: First, product policy shall ensure that the performance of front-runner products in terms of sustainability becomes the norm, and second, the effectiveness of the current Ecodesign legislative framework is going to be significantly improved. Within this paper, already existing front-runner approaches and recent and ongoing product policy-making processes were reviewed. Based on the results, an EU front-runner approach is outlined. The presented approach (i) refers to performance levels of the best products already available on the market, (ii) aggregates information in existing databases, and (iii) works semi-automated. Together, all three attributes have a high potential to facilitate and accelerate the specification of appropriate minimum requirements for products at the EU level. This way, EU policymakers can deliver on the core objectives of the Ecodesign legislative framework much better. The basic mechanism and its legal entrenchment of the approach are illustrated for the energy efficiency of energy-related products. In addition, the Front-Runner Approach can be applied to any product group in the scope of the upcoming Ecodesign for Sustainable Products Regulation and to a wide range of product-related minimum requirements, such as durability, reparability, or recycled content. The study’s objective is to suggest a tailor-made and dynamic approach to keep the EU product legislation up to date using innovative technology based on the investigation of current regulations and identify the gap. Experiences from three international case studies suggest that a front-runner approach to setting energy-performance standards can drive innovation and reduce energy consumption via promoting energy-efficient products; transparency about available products is one of the key factors and can be established by a database. The EU front-runner approach comprises extending the existing energy label database (or making use of the digital product passport) and introducing a legislative procedure that triggers changes in the energy efficiency requirements in the specific EU regulations if the database shows that a certain threshold value is reached. Challenges such as limited EU staff capacities and opportunities such as increased dynamic are discussed. KW - Ecodesign KW - ESPR KW - Energy labelling KW - EPREL KW - Policy making KW - Front-runner KW - Material efficiency KW - Resource efficiency KW - Energy efficiency PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595132 DO - https://doi.org/10.3390/en17020504 VL - 17 IS - 2 SP - 1 EP - 11 PB - MDPI AN - OPUS4-59513 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Naik, Aakash Ashok A1 - Ueltzen, Katharina A1 - Ertural, Christina A1 - Jackson, Adam J. A1 - George, Janine T1 - LobsterPy: A package to automatically analyze LOBSTERruns N2 - The LOBSTER (Deringer et al., 2011;Maintz et al., 2013 ,2016 ;Nelson et al., 2020 ) software aids in extracting quantum-chemical bonding information from materials by projecting the plane-wave based wave functions from density functional theory (DFT) onto an atomic orbital basis. LobsterEnv, a module implemented in pymatgen (Ong et al., 2013) by some of the authors of this package, facilitates the use of quantum-chemical bonding information obtained from LOBSTER calculations to identify neighbors and coordination environments. LobsterPy is a Python package that offers a set of convenient tools to further analyze and summarize the LobsterEnv outputs in the form of JSONs that are easy to interpret and process. These tools enable the estimation of (anti) bonding contributions, generation of textual descriptions, and visualization of LOBSTER computation results. Since its first release, both LobsterPy and LobsterEnv capabilities have been extended significantly. Unlike earlier versions, which could only automatically analyze Crystal Orbital Hamilton Populations (COHPs) (Dronskowski & Blöchl, 1993), both can now also analyze Crystal Orbital Overlap Populations (COOP) (Hughbanks & Hoffmann, 1983) and Crystal Orbital Bond Index (COBI) (Müller et al., 2021). Extracting the information about the most important orbitals contributing to the bonds is optional, and users can enable it as needed. Additionally, bonding-based features for machinelearning (ML) studies can be engineered via the sub-packages “featurize” and “structuregraphs”. Alongside its Python interface, it also provides an easy-to-use command line interface (CLI) that runs automatic analysis of the computations and generates a summary of results and publication-ready figures. LobsterPy has been used to produce the results in Ngo et al. (2023), Chen et al. (2024), Naik et al. (2023), and it is also part of Atomate2 (2023) bonding analysis workflow for generating bonding analysis data in a format compatible with the Materials Project (Jain et al., 2013) API. KW - Materials Science KW - Automation KW - Bonding Analysis KW - Materials Properties PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595809 DO - https://doi.org/10.21105/joss.06286 VL - 9 IS - 94 SP - 1 EP - 4 PB - The Open Journal AN - OPUS4-59580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosen, Andrew S. A1 - Gallant, Max A1 - George, Janine A1 - Riebesell, Janosh A1 - Sahasrabuddhe, Hrushikesh A1 - Shen, Jimmy-Xuan A1 - Wen, Mingjian A1 - Evans, Matthew L. A1 - Petretto, Guido A1 - Waroquiers, David A1 - Rignanese, Gian-Marco A1 - Persson, Kristin A. A1 - Jain, Anubhav A1 - Ganose, Alex M. T1 - Jobflow: Computational Workflows Made Simple N2 - We present Jobflow, a domain-agnostic Python package for writing computational workflows tailored for high-throughput computing applications. With its simple decorator-based approach, functions and class methods can be transformed into compute jobs that can be stitched together into complex workflows. Jobflow fully supports dynamic workflows where the full acyclic graph of compute jobs is not known until runtime, such as compute jobs that launch other jobs based on the results of previous steps in the workflow. The results of all Jobflow compute jobs can be easily stored in a variety of filesystem- and cloud-based databases without the data storage process being part of the underlying workflow logic itself. Jobflow has been intentionally designed to be fully independent of the choice of workflow manager used to dispatch the calculations on remote computing resources. At the time of writing, Jobflow workflows can be executed either locally or across distributed compute environments via an adapter to the FireWorks package, and Jobflow fully supports the integration of additional workflow execution adapters in the future. KW - Automation KW - Workflow KW - Computational Materials Science KW - Computations KW - Software PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593104 DO - https://doi.org/10.21105/joss.05995 VL - 9 IS - 93 SP - 1 EP - 7 PB - The Open Journal AN - OPUS4-59310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Campari, Alessandro A1 - Konert, Florian A1 - Sobol, Oded A1 - Alvaro, Antonio T1 - A comparison of vintage and modern X65 pipeline steel using hollow specimen technique for in-situ hydrogen testing N2 - The transition toward a hydrogen-based economy requires a widespread transport and distribution network, and repurposed natural gas pipelines are a viable option. An assessment of the hydrogen-induced degradation of pipeline steels is needed to inject H2 gas into the existing infrastructure safely. The conservative and standardized method consists of in-situ tensile tests in an autoclave filled with high-pressure hydrogen gas. A proposed alternative method involves using a hollow specimen as containment volume and applying the gas pressure in the inner cavity. This technique has lower costs and shorter test preparation time but is not standardized yet. This study aims to evaluate and compare the tensile properties of API 5L X65 pipeline steel in two states: vintage and modern. The influence of the surface roughness is investigated through parallel tests with drilled and reamed specimens. Hydrogen tests are compared with reference tests in an inert environment. A significant hydrogen-induced decrease in tensile properties is observed, and no significant difference between vintage and modern X65 can be drawn. The reduction in tensile properties is more significant in specimens with higher inner surface roughness. The evaluation of surface conditions appears crucial when assessing the HE susceptibility of hydrogen transport and storage equipment. KW - Hydrogen embrittlement KW - Hollow specimen technique KW - Pipeline steel KW - SSRT PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603013 DO - https://doi.org/10.1016/j.engfailanal.2024.108530 VL - 163 SP - 1 EP - 15 PB - Elsevier Ltd. AN - OPUS4-60301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zorn, R. A1 - Szymoniak, Paulina A1 - Kolmangadi, Mohamed Aejaz A1 - Malpass-Evans, R. A1 - McKeown, N. A1 - Jalarvo, N. A1 - Tyagi, M. A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - Microscopic molecular mobility of high-performance polymers of intrinsic microporosity revealed by neutron scattering – bend fluctuations and signature of methyl group rotation N2 - Polymers of intrinsic microporosity exhibit a combination of high gas permeability and reasonable permselectivity, which makes them attractive candidates for gas separation membrane materials. The diffusional selective gas transport properties are connected to the molecular mobility of these polymers in the condensed state. Incoherent quasielastic neutron scattering was carried out on two polymers of intrinsic microporosity, PIM-EA-TB(CH3) and its demethylated counterpart PIM-EA-TB(H2), which have high Brunauer–Emmett–Teller surface area values of 1030 m2 g-1 and 836 m2 g-1, respectively. As these two polymers only differ in the presence of two methyl groups at the ethanoanthracene unit, the effect of methyl group rotation can be investigated solely. To cover a broad dynamic range, neutron time-of-flight was combined with neutron backscattering. The demethylated PIM-EA-TB(H2) exhibits a relaxation process with a weak intensity at short times. As the backbone is rigid and stiff this process was assigned to bendand-flex fluctuations. This process was also observed for the PIM-EA-TB(CH3). A further relaxation process is found for PIM-EA-TB(CH3), which is the methyl group rotation. It was analyzed by a jump-diffusion in a three-fold potential considering also the fact that only a fraction of the present hydrogens in PIM-EATB(CH3) participate in the methyl group rotation. This analysis can quantitatively describe the q dependence of the elastic incoherent structure factor. Furthermore, a relaxation time for the methyl group rotation can be extracted. A high activation energy of 35 kJ mol-1 was deduced. This high activation energy evidences a strong hindrance of the methyl group rotation in the bridged PIM-EA-TB(CH3) structure. KW - Polymers of Intrinsic Microporosity KW - Neutron Scattering PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604114 DO - https://doi.org/10.1039/d4sm00520a SP - 1 EP - 11 PB - RSC AN - OPUS4-60411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohr, Gunther A1 - Chaudry, Mohsin Ali A1 - Scheuschner, Nils A1 - Blasón Gonzalez, Sergio A1 - Madia, Mauro A1 - Hilgenberg, Kai T1 - Thermal history transfer from complex components to representative test specimens in laser powder bed fusion N2 - Additively manufactured components are characterized by heterogeneous mechanical properties due to variations of the microstructure, flaws and residual stresses resulting from the inhomogeneous fabrication process. The large number of influencing factors poses a further challenge in understanding the correlation between material properties, process parameters and component geometry. Therefore, the qualification of components based on witness specimens produced within the same job is questionable. This work aims to present a new strategy for the characterization of PBF-LB/M components based on representative specimens. The key assumption is the feasibility of a transfer of the thermal history from a component to a specimen. It is assumed that similar material properties are determined for components and specimens produced adopting a similar thermal history. After the definition of a region of interest in the component, a combination of thermal analyses by means of finite elements and in-situ experimental determination of the thermal history through infrared thermography is used to produce test coupons with a similar thermal history. The effectiveness of the procedure is demonstrated on a pressure vessel for applications in the chemical industry. KW - Additive manufacturing KW - Heat accumulation KW - Thermal history KW - In situ monitoring KW - Process simulation KW - Representative specimens PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602651 DO - https://doi.org/10.1007/s40964-024-00689-8 SN - 2363-9512 SN - 2363-9520 SP - 1 EP - 16 PB - Springer CY - Cham, Switzerland AN - OPUS4-60265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -