TY - JOUR
A1 - Nicolai, Marcel
A1 - Bulling, Jannis
A1 - Narayanan, M.M.
A1 - Zeipert, Henning
A1 - Prager, Jens
A1 - Henning, Bernd
T1 - Dynamic interface behavior in coupled plates: Investigating Lamb wave mode repulsion with a spring-based model
N2 - This study investigates the phenomenon of mode repulsion in Lamb waves propagating through two coupled plates with an elastic interface. Using a spring-based coupling model and the Scaled Boundary Finite Element Method, the dispersion curves of the coupled system are analyzed under various interface conditions—weak coupling, sliding boundary, and perfect coupling. This research highlights how the mechanical stiffness of the interface influences the separation of modes and the emergence of repulsion regions. A novel focus on interface displacements reveals a unique dynamic behavior within the repulsion regions, driven by in-phase and out-of-phase oscillations of the coupled plates. The findings provide a physically grounded explanation of mode repulsion, linking it to the strain patterns in the interface. This insight lays the theoretical groundwork for future applications in material characterization and non-destructive evaluation, enabling more precise selection of Lamb wave modes for scientific and industrial purposes.
KW - Lamb waves
KW - Mode repulsion
KW - Coupled plates
KW - Elastic interface
KW - Dispersion curves
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642245
DO - https://doi.org/10.1016/j.ultras.2025.107799
SN - 0041-624X
VL - 158
SP - 1
EP - 9
PB - Elsevier BV
AN - OPUS4-64224
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Yi
A1 - Xue, Boyang
A1 - Riedel, Jens
T1 - Enhancement of LIBS plasma in air with organic solvent vapors
N2 - Laser-induced breakdown spectroscopy (LIBS) offers versatile, field-deployable elemental analysis; however, compact, high-repetition-rate nanosecond laser systems typically face constraints in power consumption and size, often compromising emission intensity and thus analytical performance. We demonstrate a significant improvement in LIBS signals through the controlled introduction of common organic solvent vapors into a sheath gas, with a diode-pumped solid-state laser (1064 nm, 2–28 kHz repetition rate, 450–600-μJ pulse energy). Optical and acoustic diagnostics reveal up to ca. 40-fold enhancement of the N II emission line at 567 nm when ambient air serves as the analyte. Maximal enhancement occurs at intermediate repetition rates of ca. 15 kHz, particularly at pulse energies approaching the optical breakdown threshold; this observation suggests a viable strategy for operating LIBS at lower pulse energies and higher repetition rates. Enhancement effects scale jointly with both vapor pressure and ionization energy of the organic species, with acetone and toluene markedly outperforming methanol and isopropanol. These findings provide a rational foundation for significantly improving the analytical performance of portable LIBS instruments without exceeding platform-specific constraints.
KW - LIBS
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653758
DO - https://doi.org/10.1016/j.sab.2025.107309
SN - 0584-8547
VL - 236
SP - 1
EP - 6
PB - Elsevier B.V.
AN - OPUS4-65375
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Holzer, Marco
A1 - Johansen, Sidsel M.
A1 - Christensen, Johan F.S.
A1 - Smedskjaer, Morten M.
A1 - Cicconi, Maria Rita
A1 - de Ligny, Dominique
A1 - Müller, Ralf
A1 - de Camargo, Andrea S.S.
A1 - Maaß, Robert
T1 - Direct connection between secondary relaxation mode and fracture toughness in alkali-aluminosilicate glasses
N2 - Oxide glasses are intrinsically brittle, lacking sufficient atomic-scale mechanisms that can relax mechanical stresses in the vicinity of a propagating crack. As a result, fracture is typically well-captured by considering local bond rupture at the crack tip. Here we demonstrate that barrier energies related to the low-temperature 𝛾-relaxation mode in alkali-aluminosilicate glasses are inversely related to the fracture toughness measured via standardized three-point bending fracture experiments. This holds true for both a series with varying cations (Li, Na, K) and one with varying Li concentration. The structural rationale for this finding is gained via Raman spectroscopy. The findings suggest that a fundamental structural relaxation mode measured on bulk specimens can serve as an effective guideline for fracture toughness of oxide glasses. Data for additional silicate glasses support this conclusion.
KW - Fracture toughness
KW - Oxide glass
KW - Mechanical properties
KW - Alkali-aluminosilicate glasses
KW - Internal friction
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651540
DO - https://doi.org/10.1016/j.mtadv.2025.100669
SN - 2590-0498
VL - 29
SP - 1
EP - 10
PB - Elsevier Ltd.
CY - Amsterdam, Niederlande
AN - OPUS4-65154
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rashidi, Reza
A1 - Vaerst, Olivia
A1 - Riechers, Birte
A1 - Rösner, Harald
A1 - Wilde, Gerhard
A1 - Maaß, Robert
T1 - Atomic-scale strain fluctuations as an origin for elastic microstructures in metallic glasses
N2 - Metallic glasses (MGs) exhibit an elastic microstructure that spans from a few to hundreds of nanometers, the origin of which continues to remain poorly understood. Here we employ four-dimensional scanning transmission electron microscopy (4D-STEM) on a Zr65Cu25Al10 (at. %) bulk MG. Mapping local diffraction patterns over representative areas also probed elastically with automated nanoindentation, two comparable correlation length scales have been identified. Specifically, local diffraction patterns are analyzed with respect to their ellipticity, revealing systematic fluctuations between positive and negative volumetric strains. A power spectrum analysis of the strain fluctuations returns a dominant length scale of the order of 100 nm, which is very much compatible with what elastic property mapping indicates. Annealing reduces the magnitude of the statistical strain fluctuations, without strongly affecting the associated fluctuation length scale. These findings demonstrate that atomic-scale strains are very likely the origin of the structurally unexpected large elastic fluctuations obtained in nanoscale contact mechanics experiments.
KW - Metallic glass
KW - 4D-STEM
KW - Strain anisotropy
KW - Nanoindentation
KW - Elastic microstructure
KW - Heterogeneities
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654991
DO - https://doi.org/10.1016/j.actamat.2026.121982
SN - 1359-6454
VL - 308
SP - 1
EP - 8
PB - Elsevier Inc.
AN - OPUS4-65499
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fischer, Tim
A1 - Huber, Norbert
T1 - Microstructure and orientation effects on microcompression-induced plasticity in nanoporous gold
N2 - Understanding the plastic deformation of nanoporous metals requires a detailed examination of their small-scale microstructural features. In this work, we present a computational study of micropillar compression in single crystal nanoporous gold (NPG) using crystal plasticity. This approach enables a systematic investigation of three key microstructural effects, including ligament size (50 ≤ 𝑙 ≤ 400 nm), solid fraction (0.2 ≤ 𝜑 ≤ 0.3), and initial crystal orientation ([001] and [111] ̄ ), on the plastic response far beyond yielding. After validation against experimental data, the study reveals that, in line with the ’smaller is stronger’ trend, besides the yield strength, the strain hardening rate also increases as ligament size decreases. Moreover, the strain hardening rate follows a power-law scaling with solid fraction, similar to the yield strength. The analysis of two distinct crystal orientations presents findings contrasting with previous assumptions. While the yielding onset remains orientation-independent, as expected, an increase in the strain hardening rate emerges for the harder [11-1] orientation with continued compression. An effect that becomes more pronounced with increasing solid fraction and decreasing ligament size. Under these conditions, harder orientations also amplify local stress heterogeneity. Notably, the stress distribution in NPG is nearly twice as wide as that observed in the single crystal bulk material (𝜑 = 1.0). Compared to the crystal plasticity approach, traditional isotropic plasticity predicts more uniform local stress fields.
KW - Nanoporous gold
KW - Microcompression
KW - Plasticity
KW - Size effect
KW - Micromechanics
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650137
DO - https://doi.org/10.1016/j.actamat.2025.121798
SN - 1359-6454
VL - 304
SP - 1
EP - 13
PB - Elsevier Inc.
AN - OPUS4-65013
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Durlo Tambara, Luís Urbano
A1 - Nikoonasab, Ali
A1 - Radtke, Martin
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Gluth, Gregor
T1 - Determination of the oxidation depths of ground granulated blast furnace slag-containing cement pastes using Mn K-edge X-ray absorption near-edge structure spectroscopy
N2 - The redox potential of the pore solution of hardened cements containing ground granulated blast furnace slag (GGBFS) affects reinforcement corrosion and immobilization of radioactive waste. Here, Mn K-edge X-ray absorption near-edge structure (XANES) spectroscopy was applied to determine the depth profile of the oxidation state of manganese in hardened GGBFS-containing cement pastes. Manganese was oxidized in the outer regions of some of the pastes, but the depth to which this occurred was not identical with the ‘blue-green/white color change front’, usually interpreted as indicating oxidation of sulfur species. For CEM III/B, the color change of the material was gradual and thus unsuitable for a precise determination of the oxidation depth, while for the alkali-activated slag, a distinct color change front was found, but full oxidation of manganese and sulfur had not occurred in the brighter region. Mn K-edge XANES spectroscopy is thus a more reliable method than the determination of the visual color change front to follow the ingress of the oxidation front.
KW - Manganese
KW - Oxidation
KW - Sulfide
KW - Alkali-activated materials
KW - Redox conditions
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651469
DO - https://doi.org/10.1111/jace.70445
SN - 0002-7820
SN - 1551-2916
VL - 109
IS - 1
SP - 1
EP - 11
PB - Wiley
CY - Oxford
AN - OPUS4-65146
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Campari, Alessandro
A1 - Konert, Florian
A1 - Razavi, Nima
A1 - Sobol, Oded
A1 - Alvaro, Antonio
T1 - Hydrogen-assisted cracking: A deep learning approach for fractographic analysis
N2 - Hydrogen handling equipment suffers from interaction with their operating environment, which degrades the mechanical properties and compromises component integrity. Hydrogen-assisted cracking is responsible for several industrial failures with potentially severe consequences. A thorough failure analysis can determine the failure mechanism, locate its origin, and identify possible root causes to avoid similar events in the future. Postmortem fractographic analysis can classify the fracture mode and determine whether the hydrogen-metal interaction contributed to the component’s breakdown. Experts in fracture classification identify characteristic marks and textural features by visual inspection to determine the failure mechanism. Although widely adopted, this process is time-consuming and influenced by subjective judgment and individual expertise. This study aims to automate fractographic analysis through advanced computer vision techniques. Different materials were tested in hydrogen atmospheres and inert environments, and their fracture surfaces were analyzed by scanning electron microscopy to create an extensive image dataset. A pre-trained Convolutional Neural Network was finetuned to accurately classify brittle and ductile fractures. In addition, Grad-CAM interpretability method was adopted to identify the image regions most influential in the model’s prediction and compare the saliency maps with expert annotations. This approach offered a reliable data-driven alternative to conventional fractographic analysis.
KW - Failure analysis
KW - Fractographic analysis
KW - Hydrogen embrittlement
KW - Material compatibility
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646610
DO - https://doi.org/10.1016/j.commatsci.2025.114366
SN - 0927-0256
VL - 262
SP - 1
EP - 16
PB - Elsevier Science
CY - Amsterdam [u.a.]
AN - OPUS4-64661
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tóth, Péter
A1 - Hofmann‐Böllinghaus, Anja
A1 - Dumont, Fabien
A1 - Anderson, Johan
A1 - Sjöström, Johan
A1 - Bergius, Mikael
A1 - Chiva, Roman
A1 - Lalu, Octavian
T1 - Finalisation of the European Approach to Assess the Fire Performance of Facades—Brief Information on the Outcome of the Project
N2 - This research was conducted within the framework of project SI2.825082, funded by the European Commission—DG GROW. The project's objective was to finalise a European approach for assessing the fire performance of façades under medium and large fire exposure conditions. The national standards BS 8414‐1:2020/BS 8414‐2:2020 and DIN 4102‐20:2017 served as the foundation for developing the new assessment method. As part of the project, a theoretical round robin, initial testing activities and a large‐scale experimental round robin were carried out. The theoretical round robin aimed to examine how different laboratories interpreted the preliminary assessment method. Subsequently, the initial testing phase explored the design of the fire source, combustion chamber and secondary opening. The experimental round robin involved testing four façade systems across three laboratories using the assessment method documents, resulting in 12 tests for medium‐scale and 12 for large‐scale exposure—24 tests in total. These tests provided data to develop a calibration scheme and define appropriate performance criteria for classification. In this paper, the representatives of the project consortium summarise the research process and outline the proposed testing and evaluation methodology, which is intended to form the foundation of a future European testing standard for façades. The article also highlights the need for further research to establish rules for extended application of test results.
KW - Facade
KW - Testing
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654731
DO - https://doi.org/10.1002/fam.70042
SN - 0308-0501
SP - 1
EP - 27
PB - John Wiley & Sons Ltd.
AN - OPUS4-65473
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wiesner, Yosri
A1 - Eisentraut, Paul
A1 - Altmann, Korinna
T1 - One Year Observation of Microplastic Concentrations in the River Rhine
N2 - In recent years, the quantification of microplastics (MP) in aquatic environments has gained increasing attention, particularly regarding their environmental distribution and potential exposure levels. Environmentally relevant exposure data are still essential for a realistic risk assessment of the harmful health potential of microplastics in freshwater systems. This study addresses a large data set of MP concentrations analyzed and processed under statistical aspects and provides mass concentrations as well as associated size fractions of the detected MP. Over a 12 month period, samples were collected at three locations and analyzed across three particle size fractions (100−500 μm, 50−100 μm, and 10−50 μm) using thermalextraction desorption-gas chromatography/mass spectrometry (TED-GC/MS). The most prevalent polymers identified were polyethylene (PE), polypropylene (PP), polystyrene (PS), styrene−butadiene rubber (SBR), and natural rubber (NR). Statistical analyses, including principal component and cluster analysis, revealed size-dependent patterns,minor seasonal variation and spatial variations. These findings are particularly significant for ecotoxicological research and regulatory development, especially regarding tire abrasion a rarely quantified but potentially harmful MP source. The study contributes aluable data for future environmental monitoring and supports EU directives on wastewater and drinking water quality
KW - TED-GC/MS
KW - Microplastics
KW - Environment
KW - Monitoring
KW - Reference data
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654669
DO - https://doi.org/10.1021/acsestwater.5c00530
SN - 2690-0637
SP - 1
EP - 10
PB - American Chemical Society (ACS)
AN - OPUS4-65466
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sobczak, M.
A1 - Lecompagnon, Julien
A1 - Hirsch, Philipp Daniel
A1 - Pieczonka, Ł.
A1 - Ziegler, Mathias
T1 - Impact damage characterization on CFRP parts using laser line scanning active thermography
N2 - This study presents a dual-path data processing framework for the detection and characterization of barely visible impact damage (BVID) in carbon-fiber-reinforced polymer (CFRP) structures using laser line thermography (LLT). A robotic LLT system was used to scan impacted CFRP specimens, and the resulting thermal sequences were analyzed using two complementary methods: full thermogram reconstruction followed by Pulse Phase Thermography (PPT) to detect subsurface delaminations, and Time-Summed Gradient Filtering (TSGF) to enhance surface-breaking cracks. Both processing paths produced interpretable results that were fused into a unified combined image and overlay mask, enabling simultaneous visualization of different defect types from a single scan. Quantitative analysis was performed on the binary masks to extract defect dimensions and Signal-to-noise ratio (SNR) values. The results demonstrated that delaminations and multiple cracks could be accurately detected and spatially distinguished, with good agreement to reference methods such as flash thermography and vibrothermography. This work highlights the potential of LLT as a versatile and scalable inspection technique, where multimodal defect detection and segmentation can be achieved through targeted processing and data fusion strategies.
KW - Active thermography
KW - CFRP
KW - Laser line scanning
KW - Delamination
KW - Cracks
KW - BVID
KW - NDT
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654097
DO - https://doi.org/10.1016/j.compositesb.2026.113425
SN - 1359-8368
VL - 313
SP - 1
EP - 9
PB - Elsevier Ltd.
AN - OPUS4-65409
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schröder, Nina
A1 - Uhlig, Marvin
A1 - Kromm, Arne
A1 - Schröpfer, Dirk
A1 - Höfer, Kevin
A1 - Hensel, Jonas
A1 - Kannengießer, Thomas
T1 - Challenges in the evaluation of the weldability of old mild steels for future use
N2 - For reasons of sustainability and cost efficiency, there is an increasing trend in the steel-processing industry to retrofit existing structures, avoiding costly shutdowns or dismantling. Although welding is a cost-effective joining method, it is rarely applied to old steels, whereas riveted or bolted connections are often uneconomical. Repair and refurbishment frequently require the replacement of damaged material or the creation of dissimilar old–new steel joints. Due to the varied manufacturing processes of historical steels, not all twentieth-century steels are inherently weldable, making an initial assessment of weldability
essential. In this study, a historical non-deoxidized mild steel (produced by Siemens–Martin processing) originating from the construction of the Berlin Radio Tower (erected in 1926) was investigated using dilatometry to analyze its welding behavior. A database of welding CCT diagrams and HAZ simulations was established to support practice-oriented welding experiments, providing key insights into their weld-metallurgical behavior and weldability. Furthermore, initial welding trials were conducted, and the local residual stress states in dissimilar old–new steel joints were determined. These foundational investigations are critical for the development of innovative, load-adapted welding concepts for the repair and refurbishment of existing old-steel infrastructure in Germany.
KW - Old mild steels
KW - Repair welding
KW - Weldability
KW - Thermo-physical simulation
KW - CCT diagrams
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654784
DO - https://doi.org/10.1007/s40194-026-02366-6
SN - 1878-6669
SP - 1
EP - 14
PB - Springer nature
AN - OPUS4-65478
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - George, Janine
A1 - Ouellet-Plamondon, Claudiane
A1 - Reyes, Kristofer
T1 - Introduction to the “Accelerate Conference 2023–2024” themed collection
N2 - The collection showcases the ways in which automation, machine learning and robotics are transforming experimental materials science and chemistry into continuous, computationally integrated processes. It features innovations regarding autonomous laboratories, Bayesian optimisation, high-throughput experimentation and computation, and AI-driven literature extraction, which simplify and scale up materials discovery. Together, these works outline a modular, responsible framework for accelerating scientific progress through human-guided, data-driven autonomy.
KW - Automation
KW - Materials Acceleration Platforms
KW - Synthesizability
KW - Workflows
KW - Large Language Models
KW - Ontologies
KW - Materials Discovery
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654658
DO - https://doi.org/10.1039/d5dd90057c
SN - 2635-098X
SP - 1
EP - 2
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65465
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Spitzer, Stefan
A1 - Amyotte, P.
A1 - Salzano, E.
T1 - Explosion behavior of hybrid mixtures
N2 - Flammable mixtures of dusts with gases or liquids occur in the process and energy industries. Most research about these so-called "hybrid mixtures" was, and still is, about coal dust with the admixture of methane because of their occurrence in the mining industry. In the modern industry, hybrid mixture explosions play an increasing role in many existing processes like spray-drying, or in emerging technologies like the direct reduction of iron ore with hydrogen or nuclear/fusion reactors. While some safety characteristics of one of the component substances stay the same or are unaffected by the concentrations that occur in the process, others are severely influenced by only traces of the other substance.
This review paper shows in which processes and applications hybrid mixtures pose a risk and gives an overview of the research conducted in the last 150 years. Findings that are reproducible and represent current proven knowledge are stated and compared to each safety characteristic containing only solid particles, gases or liquids as combustible substances. Additionally, fundamental studies on the mechanisms of flame propagation in hybrid mixtures are reviewed. The significance of these studies in enhancing our understanding of explosion behaviors in hybrid mixtures is also discussed. An outlook on what has been missing so far in the literature, is also given comparing the knowledge of single substances with their mixtures, why this might not have been investigated, and where the challenges lie.
KW - Hybrid mixtures
KW - Safety characteristics
KW - Combustion regimes
KW - Industrial explosions
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654013
DO - https://doi.org/10.1016/j.pecs.2025.101276
SN - 0360-1285
VL - 113
SP - 1
EP - 24
PB - Elsevier
CY - Amsterdam
AN - OPUS4-65401
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodriguez, Santiago
A1 - Kumanski, Sylvain
A1 - Ayed, Zeineb
A1 - Fournet, Aurélie
A1 - Bouanchaud, Charlène
A1 - Sagar, Amin
A1 - Allemand, Frédéric
A1 - Baulin, Vladimir A.
A1 - Resch‐Genger, Ute
A1 - Cortés, Juan
A1 - Sibille, Nathalie
A1 - Chirot, Fabien
A1 - Wegner, Karl David
A1 - Antoine, Rodolphe
A1 - Le Guével, Xavier
A1 - Bernadó, Pau
T1 - Programming the Optoelectronic Properties of Atomically Precise Gold Nanoclusters Using the Conformational Landscape of Intrinsically Disordered Proteins
N2 - The rational design of hybrid nanomaterials with precisely controlled properties remains a central challenge in materials science. While atomically precise gold nanoclusters (Au‐NCs) offer molecule‐like control over a metallic core, tuning their optoelectronic behavior via surface engineering is often empirically driven. Here, we establish a design principle by demonstrating that the conformational landscape of intrinsically disordered proteins (IDP) can be used as a programmable scaffold to rationally modulate the photophysical properties of a covalently bound Au‐NC. We synthesized a series of bioconjugates between Au 25 nanoclusters and bioengineered IDPs containing a variable number of cysteine anchoring points. A combination of mass spectrometry, small‐angle X‐ray scattering, and modeling on the conjugates indicates that increasing the number of covalent anchors systematically restricts the conformational ensemble, inducing a progressively more compact protein shell around nanoclusters. This structural rigidification at the interface directly translates into a 15‐fold enhancement of the Au‐NC near‐infrared photoluminescence and a six‐fold increase in its average lifetime. Our findings demonstrate that the conformational plasticity of IDPs and the capacity to engineer them can be harnessed as a molecular tuning knob, moving to a new regime of programmable soft‐matter control over the properties of quantum‐confined nanomaterials for tailored biotechnological applications.
KW - Fluorescence
KW - Custer
KW - Nano
KW - Advanced material
KW - Characterization
KW - Fluorescence quantum yield
KW - Integrating sphere spectroscopy
KW - Thiol ligands
KW - Gold
KW - Surface chemistry
KW - SWIR
KW - Mass spectrometry
KW - Protein
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655086
DO - https://doi.org/10.1002/chem.202502991
SN - 0947-6539
SP - 1
EP - 9
PB - Wiley VHC-Verlag
AN - OPUS4-65508
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rastgou, Masoud
A1 - Hülagü, Deniz
A1 - Danilenko, Aleksandr
A1 - Manoocheri, Farshid
A1 - Hertwig, Andreas
A1 - Ikonen, Erkki
T1 - Comparison of thin-film thickness measurements using ellipsometry and reflectometry with uniform samples
N2 - This study evaluates spectroscopic ellipsometry and reflectometry using high-quality SiO2 and Al2O3 thin-films on Si substrates, thereby facilitating a detailed assessment of consistency of measurement results and uncertainty analyses. The results with detailed uncertainty budgets indicate good agreement between the two methods across a broad layer thickness range from 10 nm to 2000 nm, with deviations remaining well within the measurement uncertainties. Ellipsometry results have lower uncertainty than reflectometry results especially with the thinner layers, whereas reflectometry uncertainties are lower with the thickest layers studied. This work underscores the importance of rigorous thickness characterization and reliable uncertainty evaluation as critical factors in advancing both modeling and measurement practices in thin-film metrology.
KW - Ellipsometry
KW - Reflectometry
KW - Thin Film Metrology
KW - Measurement Accuracy
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655209
DO - https://doi.org/10.1088/1681-7575/ae3964
SN - 0026-1394
VL - 63
IS - 1
SP - 1
EP - 14
PB - IOP Publishing
CY - Bristol, UK
AN - OPUS4-65520
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bernardy, Christopher
A1 - Habib, Abdel Karim
A1 - zur Nedden, Philipp Maximilian
A1 - von Saldern, Jakob Georg Raimund
A1 - Beuth, Jan Paul
A1 - Orchini, Alessandro
T1 - Thermal Radiation Of Inclined Large Scale Hydrogen Jet Flames
N2 - In order to assess the thermal radiation emanating from hydrogen jet flames, experiments under real scale conditions were carried out at the Test Site Technical Safety of BAM. Herein, the behavior of inclined hydrogen jet flames was investigated. The aim of the work is to determine the Surface Emissive Power (SEP) and radiant heat fraction of these flames and to provide a reliable dataset for model evaluation purposes. Since the aforementioned values are not directly measurable, the incident heat radiation was measured at defined distances from the flame, as well as the flame’s shape and size. The required values were then derived from these measurements. The hydrogen releases ranged from 0.0125 kg/s to 0.175 kg/s with a 30 mm orifice. The mass flows were held constant during the releases, nevertheless a transient behavior of the flame could be observed since the experiments were carried out under open field conditions, with unsteady wind fields. In the literature, the flame lengths are often determined using visible light imaging, either by injecting coloring substances in the low light emitting hydrogen jet flame or by carrying out the measurements in darkness. In this work the jet flames were visualized using infrared (IR) and OH* imaging. The recorded flame shapes and resulting flame lengths are compared. Results from this showed that the flame lengths determined with OH* and IR recordings differ greatly. A flame length ratio lf OH*/lf IR in the range of 0.47–0.62 can be found. In addition, the SEP differ also in the range of 10 kW/m2–16 kW/m2 (IR) and 40 kW/m2–80 kW/m2 (OH*) for hydrogen jet flames due to differences in the determined flame surface. Conclusions regarding the determined xRAD values for IR and OH* result in approximately the same range of 0.031–0.043.
T2 - 11th Iinternational conference on hydrogen safety 2025
CY - Seoul, Republic of Korea
DA - 22.09.2025
KW - Hydrogen safety
KW - Jet flames
KW - Thermal radiation
KW - Large scale experiment
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655181
DO - https://doi.org/10.58895/hysafe.27
SN - 2943-5935
VL - 3
IS - 1
SP - 39
EP - 50
PB - Karlsruhe Institute of Technology Library
AN - OPUS4-65518
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, Hans R.
A1 - Weidner, Steffen
A1 - Meyer, Andreas
T1 - Poly(butylene terephthalate): About condensation, cyclization, degradation and elimination reactions in the solid state, and the role of smooth crystal surfaces
N2 - Three commercial poly(butylene terephthalate) (PBT) samples - Pocan B1300 (B13), Pocan B1600 (B16), and Addigy P 1210 (AP121) - served as the starting materials for the annealing experiments, which were conducted with and without the addition of esterification and transesterification catalysts. The catalysts used were Sn(II) 2-ethylhexanoate (SnOct₂), Zr(IV) acetylacetonate, and 4-toluene sulfonic acid (TSA). Temperatures varied between 150 and 210 °C. The PBT samples were characterized using differential scanning calorimetry (DSC), gel permeation chromatography (GPC), small-angle X-ray scattering (SAXS), and matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry. The MALDI mass spectra of all three samples differed greatly but displayed mass peaks of cycles. Similar results were produced by annealing with SnOct₂ or Zr(acac)₄, which favored the formation of even-numbered cycles within the mass range below m/z 5000, along with slow degradation. TSA favored a more intensive degradation without the formation of cycles or even with the destruction of cycles. PBT chains with two carboxylic (COOH) end groups were the most stable species under all circumstances. The origin of the extremely high melting point of AP121 (241–242 °C) can be explained by the smoothing of crystallite surfaces via transesterification. The results suggest that combining MALDI mass spectrometry and SAXS measurements provides a new way to better understand the solid-state chemistry of PBT and related polyesters.
KW - MALDI-TOF MS
KW - Polybutylene Terephthalate
KW - Crystallization
KW - solid state
KW - cyclization
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652844
DO - https://doi.org/10.1016/j.polymdegradstab.2025.111862
SN - 0141-3910
VL - 245
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-65284
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dalgic, Mete‐Sungur
A1 - Kumar, Sourabh
A1 - Weidner, Steffen
T1 - Quantitative Analysis of Polymers by MALDI‐TOF Mass Spectrometry: Correlation Between Signal Intensity and Arm Number
N2 - The signal intensities of linear and star‐shaped poly(L‐lactides) (PLA) and poly (ethylene oxides) (PEO) were compared to determine the influence of the number of arms on the ionization in matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. In this study, a variety of blends were prepared and investigated, including binary and ternary combinations of linear and star‐shaped polymers with similar molecular masses. The focus was on examining their intensity ratios. In equimolar binary PLA blends, polymer stars were observed to exhibit higher intensities than their linear counterparts. This result was supported by experiments with equimolar ternary PLA blends, which clearly demonstrated an intensity dependence on the number of polymer arms. It was observed that four‐arm PLA exhibited higher intensities than three‐arm PLA. A similar trend was observed in investigations involving acetylated polymer end groups, suggesting that differences in ionization are primarily influenced by polymer architecture rather than end groups. In order to validate this assumption, the binding energies for [polymer‐K] + adduct ions utilizing the most stable geometry obtained from GOAT (Global Optimizer Algorithm) were calculated, revealing that star‐shaped lower mass oligomers have slightly higher binding energies.
KW - MALDI-TOF MS
KW - Starlike polymers
KW - Quantification
KW - Topology
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653401
DO - https://doi.org/10.1002/jms.70023
SN - 1076-5174
VL - 61
IS - 1
SP - 1
EP - 12
PB - John Wiley & Sons Ltd.
AN - OPUS4-65340
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gladrow, K.
A1 - Unkovskiy, A.
A1 - Yassine, J.
A1 - Gaertner, N.
A1 - Topolniak, Ievgeniia
A1 - Henning, N.
A1 - Schmidt, F.
T1 - The effect of nitrogen atmosphere during post-curing on cytotoxicity, polishability, flexural strength, and surface hardness of 3D-printed denture bases: an in vitro study
N2 - 3D printing is increasingly utilized in dentistry. Compared to traditional manufacturing methods, 3D printing provides advantages such as faster production times and the ability to create complex structures. Although biocompatible materials are available, many are only suitable for temporary applications. This study examines the impact of nitrogen-aided post-processing on the mechanical properties and cytotoxicity of 3D-printed denture bases, with the hypothesis that this post-processing will enhance material properties and decrease cytotoxicity. Specimens were fabricated from V-print dentbase (Voco GmbH, Cuxhaven, Germany) and post-processed either in nitrogen or air. The specimens were categorized into aged and non-aged groups. For comparison, specimens made from milled material were utilized. Vickers hardness, flexural strength, polishability, cytotoxicity, and degree of conversion were then assessed for all groups. The data were analyzed using a one-way ANOVA and Tukey HSD test for multiple comparisons, with a significance threshold of p < 0.05. Post-curing with nitrogen improved the degree of conversion, surface hardness, and biocompatibility of 3D-printed dental materials, confirming reduced cytotoxicity without impairing mechanical properties. Nitrogen increased polymerization and decreased harmful monomers, making it ideal for clinical applications in contact with the oral mucosa. Optimizing post-processing steps, such as curing in nitrogen, enhances biocompatibility while maintaining strength and hardness, ensuring better patient care in dental applications.
KW - Biocompatibility
KW - V-Print
KW - Cytotoxicity
KW - Nitrogen
KW - Dentistry
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654504
DO - https://doi.org/10.1007/s10856-026-07006-5
SN - 1573-4838
VL - 37
IS - 1
SP - 1
EP - 13
PB - Springer Science and Business Media LLC
AN - OPUS4-65450
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hübner, Martin
A1 - Dittmann, Florian
A1 - Kromm, Arne
A1 - Varfolomeev, Igor
A1 - Kannengiesser, Thomas
T1 - Enhancement of the fatigue strength by application of a low transformation temperature (LTT) welding consumable
N2 - Low transformation temperature (LTT) welding consumables offer a possibility to enhance fatigue strength in welded components without post-treatment. By lowering the martensite start temperature (MS), the volume expansion during transformation near ambient temperature reduces welding related tensile residual stresses in fatigue-critical areas. To evaluate this effect, longitudinal stiffeners were used, a LTT and conventional filler serve as welding consumable, also high frequency mechanical impact (HFMI) treatment was carried out. Three single-pass and six additional-pass sample series were investigated on residual stress and fatigue strength. The additional welds were applied in fatigue crack critical areas with different weld shapes, achieved by varying welding parameters. Mechanical tests on reference samples evaluated the properties of the diluted LTT welds. Although reduced toughness was observed, no fatigue cracks occurred in LTT single-pass weld roots. The fatigue strength at two million cycles increased from 81 MPa to 121 MPa compared to conventional welds, while HFMI reached 146 MPa. With an additional LTT weld pass the results varied from 138 MPa to 196 MPa, depending to the shape and residual stress state. The results show that LTT fillers effectively enhance fatigue performance, and that weld geometry and parameter selection are as critical as the chemical composition for maximizing the LTT effect.
CY - Genua, Italy
DA - 22.06.2025
KW - Low transformation temperature (LTT)
KW - Martensite start temperature
KW - Residual stress
KW - Longitudenal stiffener
KW - Fatigue strength
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654520
DO - https://doi.org/10.1007/s40194-026-02356-8
SP - 1
EP - 14
PB - Springer Nature
AN - OPUS4-65452
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kleba-Ehrhardt, Rafael
A1 - Dávila, Josué
A1 - Geissler, Johann
A1 - Mohr, Gunther
A1 - Schmidt, Johannes
A1 - Heinze, Christoph
A1 - Hilgenberg, Kai
A1 - Gurlo, Aleksander
A1 - Karl, David
T1 - Influence of Haynes 282 powder oxidation on powder properties and component quality in laser powder bed fusion
N2 - Reuse of powder in powder bed additive manufacturing is a common practice to enhance sustainability and reduce costs. However, the reusability of metal powder is limited by the oxidation of the powders. Even in a protective atmosphere, each build job leads to gradual oxidation of the powder, which has led to concerns about its impact on powder and part properties. Consequently, strict confidence intervals for oxygen content in nickel-based alloy feedstocks are enforced in the industry. Despite this, there is currently a lack of in-depth studies investigating the specific influence of oxygen on Haynes 282, a widely used nickel-based alloy. This study examines artificially aged Haynes 282 powder batches with oxygen content of 160 ppm, 330 ppm, 1050 ppm, and 1420 ppm. Detailed powder characterization was performed, including morphology, chemical composition, particle size, flowability, and packing behavior. Components were fabricated via PBF-LB/M to evaluate density and mechanical properties. The results showed that higher oxidation levels improved powder flowability and packing density. However, in manufactured parts, irregular melt tracks and increased surface roughness were observed, which could easily be removed by post-processing. No significant differences in density or mechanical properties at room temperature, such as tensile strength and elongation, were found. These findings indicate that H282 powder potentially remains suitable for reuse, even when the batches exhibit increased oxygen content, supporting discussions on revising the existing oxygen content confidence intervals for nickel-based alloys. The results highlight the potential for optimizing recycling strategies and reducing material waste in additive manufacturing processes.
KW - Additive manufacturing
KW - Powder bed fusion
KW - Powder characterization
KW - Powder oxidation
KW - Powder recycling
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654545
DO - https://doi.org/10.1016/j.addma.2025.105050
SN - 2214-8604
VL - 116
SP - 1
EP - 16
PB - Elsevier B.V.
AN - OPUS4-65454
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Avila Calderon, Luis Alexander
A1 - Schriever, Sina
A1 - Hang, Y.
A1 - Olbricht, Jürgen
A1 - Portella, P. D.
A1 - Skrotzki, Birgit
T1 - Creep reference data of single-crystal Ni-based superalloy CMSX-6
N2 - The article presents creep data for the single-crystal, [001]-oriented nickel-based superalloy CMSX-6, tested at a temperature of 980 °C under initial stresses ranging from 140 MPa to 230 MPa. The constant-load creep experiments were performed in accordance with DIN EN ISO 204:2019–4 standard within an ISO 17025 accredited laboratory. A total of 12 datasets are included, each of which includes the percentage creep extension as a function of time. The data series and associated metadata were systematically documented using a data schema specifically developed for creep data of single-crystal Ni-based superalloys. This dataset serves multiple purposes: it can be used to compare with one's own creep test results on similar materials, to verify testing setups (e.g., by replicating tests on the same or comparable materials), to calibrate and validate creep models, and to support alloy development efforts.
KW - NFDI MatWerk
KW - Referenzdaten
KW - Kriechen
KW - CMSX-6
KW - Digitalisierung
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654056
DO - https://doi.org/10.1016/j.dib.2025.112436
VL - 65
SP - 1
EP - 11
PB - Elsevier
AN - OPUS4-65405
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rahner, E.
A1 - Thiele, T.
A1 - Voss, Heike
A1 - Müller, F.A.
A1 - Bonse, Jörn
A1 - Gräf, S.
T1 - Objective, high-throughput regularity quantification of laser-induced periodic surface structures (LIPSS)
N2 - The growing demand for precise surface functionalization through laser-generated periodic surface structures highlights the necessity for efficient, reproducible, and objective evaluation methods to evaluate their structural regularity. We introduce ReguΛarity (v.1.2.7), a freely available, Python-based software with a graphical user interface for the automated, quantitative assessment of the regularity of laser-induced periodic surfaces structures (LIPSS), obtained from optical microscopy, SEM, or AFM. The software integrates image segmentation, one- and two-dimensional Fourier analyses, and gradient-based orientation determination to facilitate a comprehensive regularity analysis of grating-like (quasi-)periodic surface patterns with spatial periods Λ. This is achieved through the proposed regularity tuple R, composed of five key parameters: the normalized spread of the spatial period RΛ,2D (from 2D-FT), the normalized variation of the most frequent spatial period RΛ (from 1D-FT), the Gini coefficient G, the Dispersion of the LIPSS Orientation Angle δθ (DLOA), and the mean phase deviation . To demonstrate its applicability, we compare ideal sinusoidal patterns with SEM images obtained from LIPSS on stainless steel (AISI 316L) and aluminum alloy (AlMg5) surfaces, confirming the software’s ability to objectively distinguish between varying levels of structural regularity. ReguΛarity facilitates high-throughput analysis and data-driven process optimization in surface engineering and laser materials processing.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Image processing
KW - Regularity quantification
KW - Fourier analysis
KW - Structural homogeneity
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654070
DO - https://doi.org/10.1016/j.apsusc.2026.165919
SN - 0169-4332
VL - 726
SP - 1
EP - 12
PB - Elsevier B.V.
AN - OPUS4-65407
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pittrich, Tim
A1 - Jansen, Daniel
A1 - Weise, Frank
A1 - Stelzner, Ludwig
A1 - Dehn, Frank
T1 - Thermal decomposition in blended cement systems and its effect on fire-induced concrete spalling: Insights from XRD and TGA
N2 - Blended cements are gaining increasing popularity due to their lower CO2-footprint in comparison to ordinary Portland cement (OPC). However, this growing use raises the potential risk of buildings made with blended cement concrete being exposed to fire, which can lead to heavy damages caused by explosive concrete spalling. It has already been shown that the cement type strongly influences the fire-induced concrete spalling and the thermally induced moisture transport, however, to understand the mechanisms behind these findings the thermal decomposition behavior of the cementitious matrix must be investigated more systematically. Therefore, the phase content of three blended cement pastes (CEM II/A-LL, CEM III/A and CEM II/B-Q) was studied in comparison with a Portland cement paste (CEM I) after temperature exposure to 20 ◦C, 105 ◦C, 300 ◦C and 500 ◦C. Clear differences in the initial phase composition and their dehydration behavior between the individual cement types were recognized. In conclusion, blended cements showed lower amounts of AFt and AFm phases and additionally lower amounts of portlandite and C-(A)-S-H were found in CEM III/A and CEM II/B-Q pastes. The results suggest that higher AFt and AFm contents in CEM I, which are associated with greater water release at relatively low temperatures may ultimately reduce the spalling risk. Furthermore, C-(A)-S-H in CEM III/A and CEM II/B-Q showed increased thermal stability and large amounts of non-hydrated phases were found in every blended cement paste. Both of those aspects might contribute to thermomechanical spalling and the overall increased spalling susceptibility observed in blended cement concrete.
KW - Fire concrete spalling
KW - High temperatures
KW - Blended cements
KW - Dehydration
KW - XRD
KW - TGA
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653698
DO - https://doi.org/10.1016/j.cscm.2026.e05784
SN - 2214-5095
VL - 24
SP - 1
EP - 14
PB - Elsevier Ltd.
AN - OPUS4-65369
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Robens-Radermacher, Annika
A1 - Schmidt, Wolfram
A1 - Unger, Jörg F.
A1 - Mezhov, Alexander
T1 - Characterization of temperature influence on the structural build-up of 3D printed concrete
N2 - 3D concrete printing technologies enhance design freedom while reducing material use and costs without the need for formwork. Thereby, structural build-up is the key property governing stability and early strength evolution of 3D printed concrete after placement. Structural build-up is influenced by various factors, i.e., environmental conditions such as temperature. In this paper, the influence of ambient temperature on structural build-up was investigated through experimental and numerical approaches. Three experimental setups (small amplitude oscillatory shear, constant shear rate, and small amplitude oscillatory extensional tests) were applied to materials of increasing complexity under varying temperature conditions. A common modeling framework based on the maturity approach was developed to capture the time and temperature evolution. A stochastic framework was employed to estimate the unknown model parameters using experimental data. Experimental results demonstrate a significant temperature influence on structural build-up, consistent across all test setups and materials. The calibrated models successfully predict the structural build-up under different temperatures, confirming the applicability of the maturity approach to rheological parameters at early age. Furthermore, the stochastic parameter estimation allows a correct quantification of the uncertainties, enhancing model reliability. The comparison of two time evolution formulations indicates that a model with an additional linear stage is required for predicting the increase of the storage moduli (
$${G}{\prime}$$
G
′
,
$${E}{\prime}$$
E
′
). In conclusion, the study demonstrates that temperature significantly affects the structural build-up, and that the proposed modeling approach allows to predict this behavior.
KW - Structural build-up
KW - 3D concrete printing
KW - Rheology
KW - Temperature influence
KW - Modeling
KW - Green intelligent building
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654138
DO - https://doi.org/10.1617/s11527-025-02931-3
SN - 1359-5997
VL - 59
IS - 2
SP - 1
EP - 20
PB - Springer Science and Business Media LLC
AN - OPUS4-65413
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yu, Jialu
A1 - Oelze, Marcus
A1 - Schannor, Mathias
A1 - Nordstad, Simon
A1 - Vogl, Jochen
T1 - New Potential Haematite and Magnetite Reference Materials for Iron Isotope Measurements by Solution Nebulisation MC ‐ ICP ‐ MS and by In Situ ns ‐ LA ‐ MC ‐ ICP ‐ MS
N2 - Iron isotope ratios of haematite (Fe2O3) and magnetite (Fe3O4) provide insights into geochemical, environmental and planetary processes. In most studies, Fe isotope measurements are commonly performed using solution nebulisation multi-collector inductively coupled plasma-mass spectrometry (SN-MC-ICP-MS). Nanosecond laser ablation multi-collector inductively coupled plasma-mass spectrometry (ns-LA-MC-ICP-MS) requires minimal sample preparation, and provides spatially resolved variation of iron isotopes at micro-scale. However, homogeneous and matrix-matched haematite/magnetite reference materials are lacking for precise in situ isotopic measurement. The iron isotope ratios of two potential reference materials resembling natural haematite (HMIE-NP-B01) and natural magnetite (MAKP-NP-B01) were characterised. Size fractions between 5–63 μm of the powdered Fe oxides were milled to nanoparticles, freeze-dried, homogenised, and pressed into pellets. The materials were then evaluated using SN-MC-ICP-MS and LA-MC-ICP-MS. Sample powders of the two materials were measured by SN-MC-ICPMS after sample digestion and column separation and pressed pellets were analysed directly via ns-LA-MC-ICP-MS. In both cases iron isotope delta values are reported relative to the certified reference material IRMM-014, used as the bracketing standard (calibrator). The solution measurements yielded δ56Fe values of -0.25 ± 0.08‰ (N = 13, 2s) for HMIE-NP-B01, and -0.05 ± 0.09‰ (N = 12, 2s) for MAKP-NP-B01, considered as the preferred Fe isotope delta values. In situ isotopic analysis via ns-LA-MC-ICP-MS yielded δ56Fe values of -0.28 ± 0.28‰ (N = 19, 2s) for HMIE-NP-B01 and -0.12 ± 0.24‰ (N = 22, 2s) for MAKP-NP-B01, consistent with the solution Fe isotope data. The homogeneity of Fe isotopes of the pellets was evaluated by ns-LA-MC-ICP-MS analyses of three different positions to further confirm that both materials are isotopically homogeneous. Both materials can be considered as potential quality control and bracketing reference materials for Fe isotopic measurements by in situ ns-LA-MC-ICP-MS analysis.
KW - Laser ablation
KW - Fe isotope
KW - Fe-oxides
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654755
DO - https://doi.org/10.1111/ggr.70037
SN - 1639-4488
SP - 1
EP - 12
PB - John Wiley & Sons Ltd.
AN - OPUS4-65475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schusterbauer, Robert
A1 - Mrkwitschka, Paul
A1 - Sahre, Mario
A1 - Corrao, Elena
A1 - Zurutuza, Amaia
A1 - Doolin, Alexander
A1 - Pellegrino, Francesco
A1 - Radnik, Jörg
A1 - Donskyi, Ievgen S.
A1 - Hodoroaba, Vasile-Dan
T1 - Correlative Chemical Imaging to Reveal the Nature of Different Commercial Graphene Materials
N2 - Proper physicochemical characterization of advanced materials and complex industrial composites remains a significant challenge, particularly for nanomaterials, whose nanoscale dimensions and mostly complex chemistry challenge the analysis. In this work, we employed a correlative analytical approach that integrates atomic force microscopy (AFM), scanning electron microscopy (SEM) coupled with energy‐dispersive X‐ray spectroscopy (EDS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), Auger electron spectroscopy (AES), and Raman spectroscopy. This combination enables detailed chemical and structural characterization with sub‐micrometer spatial resolution. Three commercial graphene‐based materials of varying complexity were selected and investigated to test the analytical performance of this approach. Furthermore, one of the commercial graphene oxide samples was chemically functionalized via amination and fluorination. This allowed us to assess how surface modifications influence both the material properties and the limits of the applied analytical techniques.
KW - Analytical methods
KW - Commercial products
KW - Correlative analysis
KW - Graphene
KW - Surface imaging
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654765
DO - https://doi.org/10.1002/smtd.202502344
SN - 2366-9608
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-65476
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wallis, Theophilus
A1 - Ratanaphan, Sutatch
A1 - Darvishi Kamachali, Reza
T1 - Linking atomistic and phase-field modeling of grain boundaries I: Coarse-graining atomistic structures
N2 - The longstanding gap between atomistic and mesoscale simulations partly lies in the absence of a direct, physically grounded connection between atomic structure and mesoscale fields. In this work, we present a robust coarse-graining approach to systematically investigate the connection between phase-field and atomistic simulations of grain boundaries (GBs). The atomistic structures of 408 GBs in BCC-Fe and -Mo were studies to compute and analyze a continuous atomic density field. We discover a fundamental relationship between the GB density---defined as the average atomic density at the GB plane---and the GB excess free volume, an integral property of the boundary. An almost perfect linear correlation between the GB atomic density and GB excess free volume is identified. We also show that the width of BCC GBs, when scaled by the lattice constant, approaches a universal constant value. The relationships among GB density, width, and energy are systematically examined for various GB planes, and the GB energy--density correlations are classified with respect to GB types. It turns out that the atomic planes forming the GB strongly influence both the GB density and excess volume. The current results establish a dependable framework to bridge across scales, enabling density-based phase-field modeling of GBs with atomistic fidelity and enhancing the predictive reliability of mesoscale simulations.
KW - Density-based model
KW - Grain boundary structure
KW - Grain boundary thermodynamic
KW - Atomistic simulations
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654872
DO - https://doi.org/10.1016/j.actamat.2025.121786
SN - 1359-6454
VL - 305
SP - 1
EP - 14
PB - Elsevier Inc.
AN - OPUS4-65487
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pavlidis, Sotirios
A1 - Fischer, Eric W.
A1 - Opis-Basilio, Amanda
A1 - Bera, Ayan
A1 - Guilherme Buzanich, Ana
A1 - Álvarez-Sánchez, María
A1 - Wittek, Severin
A1 - Emmerling, Franziska
A1 - Ray, Kallol
A1 - Roemelt, Michael
A1 - Abbenseth, Josh
T1 - Ambiphilic Reactivity and Switchable Methyl Transfer at a T-Shaped Bi(NNN) Complex Enabled by a Redox-Active Pincer Ligand
N2 - We report the transition-metal-like reactivity of a geometrically constrained, ambiphilic bismuth(III) trisamide. Planarization of the Bi(III) center unlocks Bi−C bond formation when reacted with mild electrophiles (alkyl iodides and triflates) accompanied by two-electron oxidation of the utilized NNN pincer nligand. The preservation of the bismuth oxidation state is confirmed by single-crystal X-ray diffraction and X-ray absorption spectroscopy and corroborated by theoretical calculations. Sequential reduction of the oxidized ligand framework alters the reactivity of a generated Bi−Me unit, enabling controlled access to methyl cation, radical, and anion equivalents. The full [Bi(Me)(NNN)]+/•/− redox series was comprehensively characterized using NMR and EPR spectroscopy as well as spectro-electrochemistry. This work represents the first example of ligand-assisted, redox-neutral C−X bond splitting at bismuth, establishing a new paradigm for synthetic bismuth chemistry.
KW - Pincer ligand
KW - XAS
KW - Redox
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654948
DO - https://doi.org/10.1021/jacs.5c18955
SN - 0002-7863
VL - 148
IS - 2
SP - 2683
EP - 2692
PB - American Chemical Society (ACS)
AN - OPUS4-65494
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wallis, Theophilus
A1 - Darvishi Kamachali, Reza
T1 - Linking atomistic and phase-field modeling of grain boundaries II: Incorporating atomistic potentials into free energy functional
N2 - The density-based phase-field model for grain boundary (GB) thermodynamics and kinetics has offered a broad range of applications in alloy and microstructure design. Originally, this model is based on a potential energy terms that is connected to the cohesive energy of a given substance. A more rigorous approach, however, is a full consideration of an interatomic potential over the possible range of distance and therefore density. In Manuscript I of this series, we developed and thoroughly analyzed the coarse-graining of atomistic GB structures. In this work (Manuscript II), we complete the coupling between atomic and mesoscale modeling of GBs by incorporating the full interatomic potentials into the density-based free energy functional. Using GB energies calculated from atomistic simulations, the coarse-graining approach and the atomistic-integrated density-based Gibbs free energy, we effectively evaluate the density gradient energy coefficient. We found that coupling the density-based model with atomistic potentials reveal physically-sound trends in the GB equilibrium properties. A universal equation was derived to describe the potential energy contribution to the GB energy and the gradient energy coefficient for BCC-Fe and -Mo GBs, similar to the universal equation for GB excess free volume presented in Manuscript I. The proposed approach provides a mesoscale density-based model rooted in atomic-scale characteristics for reliable predictions of GB properties.
KW - Density-based model
KW - Phase-field
KW - Grain boundary structure
KW - Grain boundary thermodynamics
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654904
DO - https://doi.org/10.1016/j.actamat.2025.121787
SN - 1359-6454
VL - 305
SP - 1
EP - 17
PB - Elsevier
AN - OPUS4-65490
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scharpmann, Philippa
A1 - Leonhardt, Robert
A1 - Schmidt, Anita
A1 - Kowal, Julia
A1 - Tichter, Tim
A1 - Krug von Nidda, Jonas
T1 - Exploring restrictive overdischarge cycling as a method to accelerate characteristic ageing in lithium-ion cells
N2 - This study presents a test protocol that greatly accelerates the ageing process of lithium-ion battery cells comprising a positive electrode of nickel manganese cobalt oxide while preserving their characteristic degradation upon cyclic ageing. Applying a repetitive restricted overdischarge, resulting in a depth of discharge larger than 100%, a capacity loss of 20% is achieved over five times faster compared to conventional cycling. The well-known overdischarge degradation phenomenon of copper current collector dissolution is deliberately prevented by setting a discharge cutoff voltage above the theoretical threshold of copper oxidation. Hence, the accelerated degradation can be primarily connected to solid electrolyte interphase growth.
A comparative assessment of the ageing dynamics using electrochemical impedance spectroscopy and differential voltage analysis hints towards similar, characteristic degradation processes during accelerated and conventional ageing. A post-ageing examination of the electrical behaviour (i.e., coulombic and energy efficiency, capacity fade) under reference conditions reveals very little to no lasting damages caused by
overdischarging. Additionally, post-mortem analysis discloses no increased copper dissolution when comparing cells subjected to accelerated and conventional ageing. Generally, the developed ageing method appears suitable for providing cells with a defined state of health at a reasonable timescale without altering the main degradation mechanisms significantly.
KW - Lithium-ion cell
KW - Accelerated ageing
KW - Overdischarge
KW - Degradation processes
KW - Differential voltage analysis
KW - Electrochemical impedance spectroscopy
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650917
DO - https://doi.org/10.1016/j.jpowsour.2025.239072
SN - 0378-7753
VL - 665
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-65091
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weidner, Steffen
A1 - Meyer, Andreas
A1 - Falkenhagen, Jana
A1 - Kricheldorf, Hans R.
T1 - Cyclic polyglycolide by means of metal acetylacetonates
N2 - Glycolide was polymerized in bulk at 160 °C using various metal acetylacetonates as catalysts. Zirconium acetylacetonate was particularly efficient, enabling rapid polymerization even at 130 °C. The formation of cyclic poly(glycolic acid) (PGA), most likely via a ring-expansion polymerization (REP) mechanism, was proven by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Depending on the polymerization conditions, the formation of even-numbered cycles was favored to varying degrees. Number-average molecular weights (Mn) in the range of 2000–3500 g mol−1 were achieved with dispersities below 2.0. Wide-angle X-ray scattering (WAXS) powder patterns showed that the crystal lattice was the same as that of known linear PGAs, regardless of the Mn values. These patterns enabled a comparison of crystallinities with values derived from DSC measurements.
KW - MALDI-TOF MS
KW - Polyglycolide
KW - Crystallization
KW - Small-angle X-ray scattering
KW - Cyclization
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653731
DO - https://doi.org/10.1039/d5ra07961f
SN - 2046-2069
VL - 16
IS - 2
SP - 1757
EP - 1764
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65373
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stolar, Tomislav
A1 - Bayram, Dilara
A1 - May, Anastasia
A1 - Sundermann, Remie
A1 - Prinz, Carsten
A1 - Meyer, Klas
A1 - Myxa, Anett
A1 - Falkenhagen, Jana
A1 - Emmerling, Franziska
T1 - Selective mechanochemical conversion of post-consumer polyethylene terephthalate waste into hcp and fcu UiO-66 metal–organic frameworks
N2 - Single-use plastics strongly contribute to plastic pollution, and less than 10% of plastic waste is recycled globally. Here, we present a selective mechanochemical protocol for converting post-consumer polyethylene terephthalate (PET) transparent bottles and coloured textile waste into the porous metal–organic framework (MOF) UiO-66 materials. We used time-resolved in situ (TRIS) synchrotron powder X-ray diffraction and Raman spectroscopy to monitor the depolymerization of PET during ball milling. To convert disodium terephthalate to UiO-66, we developed base and base-free synthetic routes that lead to fcu and hcp UiO-66 phases, respectively, including the first ever synthesis of hcp UiO-66 by mechanochemistry. Our results demonstrate the potential of mechanochemistry to selectively access fcu and hcp UiO-66 phases using post-consumer PET waste.
KW - Mechanochemistry
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653958
DO - https://doi.org/10.1039/D4MR00126E
SN - 2976-8683
SP - 1
EP - 8
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65395
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gugin, Nikita
A1 - Schwab, Alexander
A1 - Carraro, Francesco
A1 - Tavernaro, Isabella
A1 - Falkenhagen, Jana
A1 - Villajos, Jose
A1 - Falcaro, Paolo
A1 - Emmerling, Franziska
T1 - ZIF-8-based biocomposites via reactive extrusion: towards industrial-scale manufacturing
N2 - Mechanochemistry, a sustainable synthetic method that minimizes solvent use, has shown great promise in producing metal–organic framework (MOF)-based biocomposites through ball milling. While ball milling offers fast reaction times, biocompatible conditions, and access to previously unattainable biocomposites, it is a batch-type process typically limited to gram-scale production, which is insufficient to meet commercial capacity. We introduce a scalable approach for the continuous solid-state production of MOF-based biocomposites. Our study commences with model batch reactions to examine the encapsulation of various biomolecules into Zeolitic Imidazolate Framework-8 (ZIF-8) via hand mixing, establishing a foundation for upscaling. Subsequently, the process is scaled up using reactive extrusion, enabling continuous and reproducible kilogram-scale production of bovine serum albumin (BSA)@ZIF-8 with tunable protein loading. Furthermore, we achieve the one-step formation of shaped ZIF-8 extrudates encapsulating clinical therapeutic hyaluronic acid (HA). Upon release of HA from the composite, the molecular weight of HA is preserved, highlighting the industrial potential of reactive extrusion for the cost-effective and reliable manufacturing of biocomposites for drug-delivery applications.
KW - Mechanochemistry
KW - Extrusion
KW - Biocompoites
KW - MOFs
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654777
DO - https://doi.org/10.1039/D5TA08276E
SN - 2050-7496
SP - 1
EP - 14
PB - Royal Society of Chemistry
AN - OPUS4-65477
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scholl, Juliane
A1 - Lisec, Jan
A1 - Bagheri, Abbas
A1 - Meiers, Emelie
A1 - Russo, Francesco Friedrich
A1 - Haase, Hajo
A1 - Koch, Matthias
T1 - Unveiling aging mechanisms of electrolytes in commercial end-of-life lithium-ion batteries
N2 - In this study, 77 end-of-life (EOL) commercial lithium-ion batteries (LIBs) of various formats were systematically analyzed to investigate electrolyte degradation and the influence of pristine electrolyte compositions on aging behavior. Comprehensive chemical characterization was conducted using targeted and non-targeted mass spectrometry (MS), employing LC-MS/MS, GC-MS, and high-resolution MS (HRMS). This integrated approach enabled the identification of confirmed pristine components and complex degradation products. The results show that rechargeable pouch and cylindrical cells often deviate from conventional model systems, containing mixed lithium salt anions, ionic liquids (ILs), and high concentrations of triflates, triflimides, and bis(fluorosulfonyl)imide (FSI). These function as solvents, salts, or safety-enhancing additives. Specific IL degradation products were identified, and hypotheses formulated on previously unreported pathways. Furthermore, a novel series of oligomerization products of propylene carbonate (PC) was detected. In contrast, non-rechargeable coin cells revealed widespread use of per- and polyfluoroalkyl substances (PFAS) in their original electrolytes. Based on ex situ analyses, hypothetical PFAS degradation mechanisms are proposed here for the first time. The absence of carbonate oligomers and lithium salt-derived products, alongside the presence of standard carbonates, indicates lithium counterion coordination as a key factor in Lewis acid-catalyzed degradation. This study offers valuable insights into real-world battery aging.
KW - Transformation products
KW - Lithium-ion batteries
KW - Fluorinated Compounds
KW - Gas chromatography/ QTOF-MS
KW - HILIC-LC-MS/MS
KW - PFAS
KW - Electrochemistry
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-644991
DO - https://doi.org/10.1016/j.jpowsour.2025.238613
SN - 0378-7753
VL - 661
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-64499
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sauer, Hannah
A1 - Okpeke, Bright E.
A1 - Dzielendziak, Agnieszka S.
A1 - Eberwein, Robert
A1 - Baetcke, Lars
A1 - Ehlers, Sören
T1 - Comparative life cycle assessment of vacuum insulation panel core materials for liquid hydrogen storage tanks – glass bubbles compared to conventional core materials
N2 - The environmental performance of insulation materials for liquid hydrogen storage tank application is important to the development of sustainable supply chains. As new materials keep evolving, there is a need to assess their environmental impact. Therefore, this study investigates the environmental sustainability and circularity of cryogenic insulation concepts, namely vacuum insulation panels (VIPs), exclusively focussing on their core materials. Employing a cradle-to-grave life cycle assessment model, the VIP core materials are investigated with a special focus on glass bubbles. Based on the results, the global warming potential of the considered core materials, namely, glass bubbles, silica aerogel, fumed silica, expanded perlite, glass fibre, and polyurethane foam is 9.21∗10^−2, 7.00, 2.50∗10^−1, 3.63∗10^−2, 6.68∗10^−2, and 1.88 kg CO2 eq. per functional unit, respectively. In general, silica aerogel and polyurethane foam are the least environmentally friendly materials, while the most sustainable is expanded perlite, followed by glass fibre, glass bubbles, and fumed silica.
KW - LH2
KW - Insulation
KW - Cryogenic storage tank
KW - Life Cycle Assessment
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655445
DO - https://doi.org/10.1016/j.ijhydene.2026.153937
SN - 0360-3199
VL - 219
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-65544
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hickel, Tilmann
A1 - Waske, Anja
A1 - Tehranchi, Ali
A1 - Bhattacharya, Biswajit
A1 - Stawski, Tomasz M.
A1 - Fellinger, Tim-Patrick
A1 - Mehmood, Asad
A1 - Witt, Julia
A1 - Ozcan, Ozlem
A1 - Guilherme Buzanich, Ana
A1 - Kumar, Sourabh
A1 - Mishra, Rajesh Kumar
A1 - Holzer, Marco
A1 - Stucchi de Camargo, Andrea Simone
A1 - Agudo Jácome, Leonardo
A1 - Manzoni, Anna
A1 - Fantin, Andrea
A1 - John, Elisabeth
A1 - Hodoroaba, Vasile-Dan
A1 - Bührig, Sophia
A1 - Murugan, Jegatheesan
A1 - Marschall, Niklas
A1 - George, Janine
A1 - Darvishi Kamachali, Reza
A1 - Maaß, Robert
A1 - Emmerling, Franziska
T1 - Chemically complex materials enable sustainable high-performance materials
N2 - Chemically complex materials (CCMats) including high-entropy alloys, oxides, and related multi-principal element systems offer a paradigm shift in materials design by leveraging chemical diversity to simultaneously optimize functional, structural, and sustainability criteria. The vastness of the compositional and structural space in CCMats propels the field into an expanding exploratory state. To reconcile functional and structural performance across this immense parameter space remains an open challenge. This Perspective evaluates the opportunities and challenges associated with harnessing chemical complexity across a broad spectrum of applications, such as hydrogen storage, ionic conductors, catalysis, magnetics, dielectrics, semiconductors, optical materials, and multifunctional structural systems. It is delineated how three central design strategies: targeted substitution (SUB), defect engineering (DEF), and diversity management (DIV) enable the reconciliation of high functional performance with long-term structural stability and environmental responsibility.
Advances in computational thermodynamics, microstructure simulations, machine learning, and multimodal characterization are accelerating the exploration and optimization of CCMats, while robust data infrastructures and automated synthesis workflows are emerging as essential tools for navigating their complex compositional space. By fostering cross-disciplinary knowledge transfer and embracing data-driven design, CCMats are poised to deliver next-generation materials solutions that address urgent technological, energy, and
environmental demands.
KW - Chemically complex materials
KW - Structural stability
KW - Functional performance
KW - Design strategies
KW - Sustainability
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655598
UR - https://www.sciencedirect.com/science/article/pii/S1359028626000033?via%3Dihub
DO - https://doi.org/10.1016/j.cossms.2026.101256
SN - 1359-0286
VL - 42
SP - 1
EP - 26
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-65559
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Shovo, Redoy Gazi
A1 - Thünemann, Andreas
A1 - Katcharava, Zviadi
A1 - Marinvo, Anja
A1 - Hoppe, Richard
A1 - Woltersdorf, Georg
A1 - Du, Mengxue
A1 - Androsch, Rene
A1 - de Souza e Silva, Juliana Martins
A1 - Busse, Karste
A1 - Binder, Wolfgang H.
T1 - Generating Tagged Micro- and Nanoparticles of Poly(ethylene furanoate) and Poly(ethylene terephthalate) as Reference Materials
N2 - Detecting nanoplastic particles in environmental samples and biological tissues remains a significant challenge, especially in view of newly emerging polymers, not yet commercially exploited. Fluorescent labeling provides a tagging strategy to overcome this limitation by reducing the detection limit of individual particles, especially for small-sized particles. We present a method for producing labeled nanoparticles (NP/MP) of poly(ethylene terephthalate) (PET) and poly(ethylene furanoate) (PEF), tagged with Alexa Fluor 633 or Alexa Fluor 647. Our preparations used mechanical grinding or solvent-based approaches (confined impinging jet mixing, ((CIJ, precipitation), generating particles with hydrodynamic diameters of 200–700 nm, displaying long-term stability in water of up to 57 days. Stable suspensions with concentrations of the particles ranging from 10 µg/mL (surfactant-free, by solvent mixing) to 5.88 mg/mL (precipitation, containing surfactant) were generated with zeta-potentials from −5 to −50 mV. Characterization of the nanoparticles by SEC, DSC, and XRD showed no significant changes in molecular weight, thermal behavior, or crystallinity via the solvent-based methods, compared to the pristine polymer, highlighting their suitability for producing standardized nanoparticle dispersions. Fluorescence spectroscopy of the Alexa-dye-labeled particles confirmed the successful incorporation of the Alexa dyes, so improving monitoring of their biological profiles of the PEF-MP/NPs. s-SNOM (near field imaging) could identify individual PEF-particles sized ∼200 nm by direct imaging.
KW - Reference Materials
KW - Nanoplastics
KW - Microplastics
KW - Polymer
KW - Fluorescence
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655531
DO - https://doi.org/10.1002/marc.202500839
SN - 1521-3927
VL - 47
IS - 4
SP - 1
EP - 11
PB - Wiley VHC-Verlag
CY - Weinheim
AN - OPUS4-65553
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Prakash, Swayam
A1 - Bell, Jérémy
A1 - Rurack, Knut
T1 - Rapid Onsite Detection of Fecal Contamination in Water Using a Portable Fluorometric Assay
N2 - Fecal pollution in water poses significant health risks, especially when contaminated sources are used for drinking and food production. Traditional water quality testing methods are expensive, slow, and require skilled personnel, limiting their accessibility. This work addresses these issues by developing a portable fluorometric assay for the detection of the fecal indicator pigment urobilin (UB). The assay uses silane-functionalized glass fiber strips impregnated with zinc chloride, providing a ‘drop-&-detect’ approach with enhanced fluorescence response mediated by the unique complexation properties of ZnCl2 and UB. This approach allows for the detection of UB at sub-nanomolar concentrations in less than 1 min using a 3D-printed setup with miniaturized optical components powered by a smartphone with its camera as a detector. The results validated with a benchtop fluorometer show the effectiveness of this method. The successful application of this userfriendly, rapid, and sensitive assay to real water samples from three rivers and the influx and efflux of a wastewater treatment plant advances field-based water quality monitoring, meets the WHO’s ASSURED criteria, and supports progress toward the global clean water and sanitation goals.
KW - Fecal pigment
KW - Fluorescence
KW - Signal amplification
KW - Surface chemistry
KW - Water quality testing
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655543
DO - https://doi.org/10.1021/acssensors.5c03922
SN - 2379-3694
VL - 11
SP - 1
EP - 9
PB - American Chemical Society
CY - Washington, D.C.
AN - OPUS4-65554
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schwibbert, Karin
A1 - de Eulate Pérez, Elisa García
A1 - Wen, Keqing
A1 - Voss, Heike
A1 - Thiele, Dorothea
A1 - Richter, Anja M.
A1 - Bonse, Jörn
T1 - Escherichia coli repellence via laser-induced periodic surface structures (LIPSS) on titanium: Critical role of biofilm-associated gene expression
N2 - The inconsistency in the observed bacteria-repellent effects of laser-induced surface textures remains a subject of scientific debates. With E. coli TG1 as test strain, we performed biofilm formation assays on ultrashort pulse laser textured titanium. Samples covered with low spatial frequency LIPSS (LSFL) of periods around 750 nm or with high spatial frequency LIPSS (HSFL) featuring smaller periods around 100 nm were processed on polished samples. While LSFL significantly reduce the number of adhering bacteria compared to the polished reference, HSFL do not. Simultaneously, we concentrate our study on bacterial strategies employed for biofilm formation, that is the transcription of the biofilm-associated genes csgB, involved in primary adhesion to a surface, and wza, participating in biofilm maturation. Promoter regions of these genes were cloned into a promotor probe plasmid with the green fluorescent protein GFP+ as reporter and transferred into the test strain. As indicated by the fluorescence intensity of the reporter protein, among the bacteria colonizing LSFL-covered areas, a markedly higher proportion of cells transcribing csgB or wza were detected, compared to the bacterial populations colonizing the polished or HSFL-covered areas. To our knowledge, this is the first study indicating that the antifouling effect of LSFL topographies can be counteracted when bacteria activate biofilm-associated genes.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Titanium
KW - Biofilm
KW - Antifouling
KW - Gene expression
KW - Fluorescence microscopy
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655572
DO - https://doi.org/10.1016/j.apsusc.2026.166363
SN - 0169-4332
VL - 730
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-65557
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pei, R.
A1 - Petrazoller, J.
A1 - Atila, Achraf
A1 - Arnoldi, S.
A1 - Xiao, L.
A1 - Liu, X.
A1 - Wang, H.
A1 - Korte-Kerzel, S.
A1 - Berbenni, S.
A1 - Richeton, T.
A1 - Guénolé, J.
A1 - Xie, Z.
A1 - Al-Samman, T.
T1 - Solute co-segregation mechanisms at low-angle grain boundaries in magnesium: A combined atomic-scale experimental and modeling study
N2 - Solute segregation at low-angle grain boundaries (LAGBs) critically affects the microstructure and mechanicalproperties of magnesium (Mg) alloys. In modern alloys containing multiple substitutional elements, understanding solute-solute interactions at microstructural defects becomes essential for alloy design. This study investigates the co-segregation mechanisms of calcium (Ca), zinc (Zn), and aluminum (Al) at a LAGB in a dilute Mg-0.23Al-1.00Zn-0.38Ca (AZX010) alloy by combining atomic-scale experimental and modeling techniques.Three-dimensional atom probe tomography (3D-APT) revealed significant segregation of Ca, Zn, and Al at the LAGB, with Ca forming linear segregation patterns along dislocation arrays characteristic of the LAGB. Clustering analysis showed increased Ca–Ca pairs at the boundary, indicating synergistic solute interactions.
Atomistic simulations and elastic dipole calculations demonstrated that larger Ca atoms prefer tensile regions around dislocations, while smaller Zn and Al atoms favor compressive areas. These simulations also found that Ca–Ca co-segregation near dislocation cores is energetically more favorable than other solute pairings, explaining the enhanced Ca clustering observed experimentally. Thermodynamic modeling incorporating calculated segregation energies and solute-solute interactions accurately predicted solute concentrations at the LAGB, aligning with experimental data. The findings emphasize the importance of solute interactionsat dislocation cores in Mg alloys, offering insights for improving mechanical performance through targeted alloying and grain boundary engineering.
KW - Atomic probe tomography
KW - Atomistic simulation
KW - Grain boundary
KW - Co-segregation
KW - Magnesium alloy
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655248
DO - https://doi.org/10.1016/j.actamat.2026.121947
SN - 1359-6454
VL - 306
SP - 1
EP - 13
PB - Elsevier Inc.
AN - OPUS4-65524
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chaudhuri, Somsubhro
A1 - Krankenhagen, Rainer
A1 - Lapšanská, Ivana
A1 - Stamm, Michael
T1 - Modeling Temperature Responses of a Wind Turbine Blade Section Under Climate Chamber Conditions – Part 1: Challenges for FEM Simulations
N2 - The rapid expansion of wind energy infrastructure over the past 20–30 years has led up to a situation where advanced non‐destructive testing (NDT) technologies are the need‐of‐the‐hour, not only for new wind turbine blades (WTBs) that are being installed, but also for older infrastructure which is reaching their designed lifetime. NDT technologies that improve both the quality as well as reduce the time required for the inspection are sought after, and one such example is passive infrared thermography (IRT). For passive IRT to provide significant information/insight into the integrity of the WTB, there needs to exist certain thermal contrast to both visualize and distinguish between features in WTB. These features could be surface features, subsurface structure or defects. The temperature variations due to air temperature fluctuations and the sun assist (passively) to obtain the necessary thermal contrast. To better understand the thermal response of composite structures such as WTBs, a validation study was conducted using a WTB section subjected to controlled temperature transients within a climate chamber, without external irradiation. Infrared measurements were recorded using a thermographic camera, and the same specimen was modeled using finite element methods (FEM) in COMSOL Multiphysics. While a direct validation of the simulation is limited due to transient and unmeasured variables in the experimental data, qualitative comparison provides valuable insight into the applicability of FEM for predicting thermal behavior in passive IRT scenarios. This article represents the first part of a two‐part study, focusing on the FEM modeling approach and associated challenges. The second part will address the experimental investigation in more detail, with an emphasis on thermal contrast behavior under varied transient conditions.
KW - Finite element modeling
KW - Non- destructive testing
KW - Passive infrared thermography
KW - Thermal contrast
KW - Wind turbine blades
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655330
DO - https://doi.org/10.1002/we.70102
SN - 1095-4244
VL - 29
IS - 3
SP - 1
EP - 14
PB - Wiley
AN - OPUS4-65533
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Redda, Zinnabu Tassew
A1 - Prinz, Carsten
A1 - Yimam, Abubeker
A1 - Barz, Mirko
A1 - Becker, Katharina
A1 - Gizaw, Desta Getachew
A1 - Laß-Seyoum, Asnakech
T1 - Structural and textural characterization of Brassica carinata biochar to investigate its potential industrial applications
N2 - Biochar, a low-cost, and carbon-rich product of the thermal decomposition of biomass under oxygen-limited conditions and at relatively low temperatures, has recently been identified as a promising porous material with a wide range of industrial applications. In the present study, a comprehensive analysis of proximate, ultimate, nutrient profile, structural, and textural properties of a biochar derived from two Ethiopian indigenous Brassica carinata cultivars was conducted. The characterization of the biochar was achieved by employing a variety of well-established methods, including proximate analysis (moisture, volatile matter, ash content, and fixed carbon), ultimate analysis (C, S, and O content), atomic oxygen to carbon ratio (O/C), morphological and elemental composition analysis through scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Furthermore, a combination of mercury intrusion porosimetry (MIP), dynamic vapor sorption (DVS), and gas adsorption methods such as nitrogen and krypton gas adsorption, were used for an in-depth study of the porous structure. SEM morphological characterization showed that the biochar surfaces showed multiple pores of diverse sizes and shapes. EDS elemental composition analysis revealed that sodium, aluminium, and silicon were not detected, but potassium, calcium, magnesium, and iron were all present in noticeable amounts. Furthermore, ultimate analysis showed that the most prevalent elements were carbon (86 wt.%) and oxygen (10.41‒9.77 wt.%), while sulphur was present in negligible concentrations. MIP analysis demonstrated that the porosities of the biochars varied from 62.68 to 69.99 wt.%, with the Holetta-1 biochar showing the highest porosity. The superior porosity of Holetta-1, as confirmed via MIP analysis, yielded higher values for bulk volume (2.36 mL g− 1), skeletal volume (1.65 mL g− 1), and total intrusion volume (1.65 mL g− 1) compared to the Yellow Dodolla. The most frequent pore diameters were 172.46 μm for Yellow Dodolla and 111.42 μm for Holetta-1. The MIP log differential pore diameter distributions were observed to vary from 18 to 411 μm and 10 to 411 μm, respectively, for Yellow Dodolla and Holetta-1. Despite the biochars’ low specific surface areas (0.17–0.21 m² g⁻¹), krypton sorption was a suitable technique for its characterization compared to DVS and nitrogen sorption methods. In conclusion, the characterization studies confirmed that this carbon-rich porous material possesses unique and valuable properties, with these attributes position it as a promising alternative for diverse industrial applications, contributing to the development of a bio-based circular economy.
KW - Morphological characterization
KW - Mercury intrusion porosimetry
KW - Gas adsorption
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655325
DO - https://doi.org/10.1038/s41598-025-32063-1
SN - 2045-2322
VL - 16
IS - 1
SP - 1
EP - 19
PB - Springer Science and Business Media LLC
AN - OPUS4-65532
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, Kun
A1 - Schukar, Marcus
A1 - Hicke, Konstantin
A1 - Lu, Xin
T1 - Effect of humidity on fiber-optic temperature sensing
N2 - This study investigates the influence of ambient humidity on the temperature sensitivity, measurement accuracy, and uncertainty of optical fibers with different coatings, using a Rayleigh-based distributed sensing technique. Polymer-coated fibers (acrylate and polyimide) and metal-coated fibers (copper and gold) were tested under controlled humidity (30%–90% RH) and temperature (20–60 °C) conditions. Rayleigh-based measurements revealed a slight but consistent decrease in temperature sensitivity with increasing humidity for all polymer-coated fibers, attributed to humidity-induced changes in coating stiffness and strain transfer. In contrast, metal-coated fibers exhibited humidity-independent behavior and superior stability. These findings highlight the non-negligible role of ambient humidity in fiber-optic temperature sensing, particularly in Rayleigh-based systems using hygroscopic coatings. The results provide practical guidance for fiber and coating selection in humid environments and offer broader insight into humidity–strain–temperature coupling mechanisms relevant to other fiber-optic sensing mechanisms.
KW - Distributed sensing
KW - Humidity effect
KW - Temperature sensing
KW - Optical fiber coatings
KW - Temperature uncertainty
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650040
DO - https://doi.org/10.1016/j.measurement.2025.119905
SN - 0263-2241
VL - 261
SP - 1
EP - 9
PB - Elsevier Ltd.
AN - OPUS4-65004
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gerrits, Ruben
A1 - Stepec, Biwen An
A1 - Bäßler, Ralph
A1 - Becker, Roland
A1 - Dimper, Matthias
A1 - Feldmann, Ines
A1 - Goff, Kira L.
A1 - Günster, Jens
A1 - Hofmann, Andrea
A1 - Hesse, René
A1 - Kirstein, Sarah
A1 - Klein, Ulrich
A1 - Mauch, Tatjana
A1 - Neumann-Schaal, Meina
A1 - Özcan Sandikcioglu, Özlem
A1 - Taylor, Nicole M.
A1 - Schumacher, Julia
A1 - Shen, Yin
A1 - Strehlau, Heike
A1 - Weise, Matthias
A1 - Wolf, Jacqueline
A1 - Yurkov, Andrey
A1 - Gieg, Lisa M.
A1 - Gorbushina, Anna
T1 - A 30-year-old diesel tank: Fungal-dominated biofilms cause local corrosion of galvanised steel
N2 - The increased use of biodiesel is expected to lead to more microbial corrosion, fouling and fuel degradation issues. In this context, we have analysed the metal, fuel and microbiology of a fouled diesel tank which had been in service for over 30 years. The fuel itself, a B7 biodiesel blend, was not degraded, and—although no free water phase was visible—contained a water content of ~60 ppm. The microbial community was dominated by the fungus Amorphotheca resinae, which formed thick, patchy biofilms on the tank bottom and walls. The tank sheets, composed of galvanised carbon steel, were locally corroded underneath the biofilms, up to a depth of a third of the sheet thickness. On the biofilm-free surfaces, Zn coatings could still be observed. Taken together, A. resinae was shown to thrive in these water-poor conditions, likely enhancing corrosion through the removal of the protective Zn coatings.
KW - Fungal biofilms
KW - Biodiesel degradation mechanisms
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655014
DO - https://doi.org/10.1038/s41529-025-00731-2
SN - 2397-2106
VL - 10
IS - 1
SP - 1
EP - 14
PB - Springer Science and Business Media LLC
AN - OPUS4-65501
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bartczak, Dorota
A1 - Sikora, Aneta
A1 - Goenaga-Infante, Heidi
A1 - Altmann, Korinna
A1 - Drexel, Roland
A1 - Meier, Florian
A1 - Alasonati, Enrica
A1 - Lelong, Marc
A1 - Cado, Florence
A1 - Chivas-Joly, Carine
A1 - Fadda, Marta
A1 - Sacco, Alessio
A1 - Rossi, Andrea Mario
A1 - Pröfrock, Daniel
A1 - Wippermann, Dominik
A1 - Barbero, Francesco
A1 - Fenoglio, Ivana
A1 - Booth, Andy M.
A1 - Sørensen, Lisbet
A1 - Igartua, Amaia
A1 - Wouters, Charlotte
A1 - Mast, Jan
A1 - Barbaresi, Marta
A1 - Rossi, Francesca
A1 - Piergiovanni, Maurizio
A1 - Mattarozzi, Monica
A1 - Careri, Maria
A1 - Caebergs, Thierry
A1 - Piette, Anne-Sophie
A1 - Parot, Jeremie
A1 - Giovannozzi, Andrea Mario
T1 - Multiparameter characterisation of a nano-polypropylene representative test material with fractionation, light scattering, high-resolution microscopy, spectroscopy, and spectrometry methods
N2 - Reference and quality control materials with comparable physicochemical properties to nanoplastic contaminants present in environmental and food nanoplastics are currently lacking. Here we report a nanoplastic polypropylene material prepared using a top-down approach involving mechanical fragmentation of larger plastics. The material was found to be homogeneous and stable in suspension and has been characterised for average particle size, size distribution range, particle number concentration, polypropylene mass fraction and inorganic impurity Content using a wide range of analytical methods, including AF4, cFFF, PTA, (MA)DLS, MALS, SEM, AFM, TEM, STEM, EDS,Raman, ICP-MS and pyGC-MS. The material was found to have a broad size distribution, ranging from 50 nm to over 200 nm, with the average particle size value dependent on the technique used to determine it. Particle number concentration ranged from 1.7–2.4 × 1010 g−1 , according to PTA. Spectroscopy techniques confirmed that the material was polypropylene, with evidence of aging due to an increased level of oxidation. The measured mass fraction was found to depend on the marker used and ranged between 3 and 5 μg g−1 . Inorganic impurities such as Si, Al, Mg, K, Na, S, Fe, Cl and Ca were also identified at ng g−1 levels. Comparability and complementarity across the measurement methods and techniques is also discussed.
KW - Polypropylene
KW - Nanoplastics
KW - Analytics
KW - Reference material
KW - Scattering methods
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654680
DO - https://doi.org/10.1039/D5EN00917K
SN - 2051-8153
SP - 1
EP - 15
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65468
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Krause, Christina
A1 - Szymoniak, Paulina
A1 - Lohstroh, W.
A1 - Juranyi, F.
A1 - Zamponi, M.
A1 - Frick, B.
A1 - Al-Sabbagh, Dominik
A1 - Emmerling, Franziska
A1 - Zorn, R.
A1 - Schönhals, Andreas
T1 - Complex molecular dynamics of symmetric model discotic liquid crystals: Comparison of Hexakis(hepta-alkanoyloxy)triphenylene (HOT6) with Hexakis(hexa-alkyloxy)triphenylene (HAT6)
N2 - This study investigates the complex molecular dynamics of discotic liquid crystals (DLCs) by comparing two structurally similar compounds: Hexakis(hepta-alkanoyloxy)triphenylene (HOT6) and Hexakis(hexa-alkyloxy)triphenylene (HAT6) having the same triphenyl core and the same length of the alkyl side chain. The difference of both materials is that the alkyl chain is linked by an oxygen bridge to the triphenylene core for HAT6 and by a ester group for HOT6. Using a combination of broadband dielectric spectroscopy, differential scanning calorimetry, X-ray scattering, and neutron scattering techniques, the research explores the glass transition phenomena and relaxation processes in these materials. HOT6, featuring ester linkages, exhibits distinct dynamic behavior compared to HAT6, including two separate glass transitions indicated by the 1- and 2-relaxation found by dielectric spectroscopy which are assigned to the glassy dynamics of the alkyl side chain in the intercolumnar space and that of the columns, respectively. The study reveals that the ester group in HOT6 leads to increased molecular rigidity and altered packing in the intercolumnar space, as evidenced by X-ray scattering and the vibrational density of states. Neutron scattering confirms localized methyl group rotations and a further relaxation process which relates to the -relaxation revealed by dielectric spectroscopy. The findings contribute to a deeper understanding of glassy dynamics in partially ordered systems and highlight the influence of molecular architecture on relaxation behavior in DLCs.
KW - Discotic Liquid Crystals
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655171
DO - https://doi.org/10.1039/d5sm01247c
SN - 1744-6848
SP - 1
EP - 17
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65517
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodricks, Carol Winnifred
A1 - Prockat, Annabell
A1 - Kalinka, Gerhard
A1 - Trappe, Volker
T1 - Novel Recyclable Hierarchical Carbon Fiber/Epoxy Composites: Preserving Fiber Length and Orientation Using Elium
N2 - Current recycling methods for polymer matrix composites produce short, unoriented carbon fibers, limiting their use to intermediate‐strength applications. A method is therefore needed to recycle fibers while preserving their original length and orientation, enabling a circular economy for carbon fiber composites. This study proposes a novel hierarchical composite designed to retain fiber length and orientation during recycling. Virgin carbon fibers are encased in an insoluble epoxy matrix to form tapes that act as the primary units of the structure. The primary tape matrix shields the fibers from chemical degradation while preserving their alignment throughout recycling. The tapes are then embedded in a secondary recyclable matrix, Elium, a thermoplastic polymer soluble in acetone with mechanical properties comparable to epoxy. The composite is recycled by dissolving the secondary Elium matrix in acetone and recovering the primary tape units with intact fiber length and orientation. The primary units can then be used to assemble new composites. In this study, hierarchical composite laminates underwent recycling up to three times. Their mechanical properties were assessed after each cycle. Laminates with an Elium secondary matrix retained 60%–90% of the mechanical performance of epoxy‐based laminates. Minimal degradation was observed between cycles, and fiber length, orientation, and volume fraction were fully preserved. Pushout tests confirmed that fibers in the primary tapes were sufficiently shielded during the recycling process. These results validate the feasibility of a hierarchical recyclable composite that combines recyclability with high mechanical performance, serving as a proof of concept and providing opportunities for future development.
KW - Review
KW - Interface
KW - Micromechanics
KW - Polymer matrix composites
KW - Glass fibre reinforced composites
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655276
DO - https://doi.org/10.1002/pc.70869
SN - 0272-8397
SP - 1
EP - 16
PB - Wiley Periodicals LLC.
AN - OPUS4-65527
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kästle, Emanuel D.
A1 - Duffner, Eric
A1 - Popiela, Bartosz
A1 - Ghaznavi, Ali
T1 - Monitoring Failure of Composite Pressure Vessels with Acoustic Emissions
N2 - Two carbon fiber reinforced type IV pressure vessels are subjected to step-wise pressurization until burst, while monitored using acoustic emissions (AE). Unlike most prior studies, AE data is collected throughout the entire damage progression. The vessels, manufactured with differing parameters, failed in distinct composite layers – A-type in the hoop layers and B-type in the helical layers. The AE signals are evaluated to study material degradation and identify fiber breaks as signs of critical damage accumulation. The signals are distributed randomly across the surface, with localized accumulation only minutes before rupture, close to the rupture plane. The difference in manufacturing parameters did not result in any clear difference in the AE activity. Felicity and Shelby ratios show consistent decline with increasing pressure, suggesting potential for damage assessment and burst prediction. It is discussed how these ratios are affected by coupling quality of the AE sensors, the shape of the pressurization profile and prior loadings. Different signal features based on the amplitude and the frequency content are extracted for a classification into failure mechanisms. Based on previous studies, AE signals corresponding to fiber breaks have a characteristic high-frequency spectrum and show a delay in occurrence, with an increase in the number of breaking fibers towards the end of the experiment. Indeed, high frequency signals tend to occur later and signals in specific peak-frequency ranges (350 – 400 kHz, 500 kHz) somewhat resemble the expected behavior. However, the dataset is too variable and too incongruent for any clear interpretations. Likely reasons are signal propagation effects, the complex composite structure, simultaneous occurrence of signals and measurement uncertainties. A review of relevant studies is provided to show that similar issues affect also previous works. Successfully identifying fiber breaks in large-scale, complex composite structures based on AE data, and turning this into an applicable health-monitoring technique, therefore remains a challenge.
KW - Acoustic emission testing
KW - Composite pressure vessels
KW - Damage classification in fiber reinforced polymers
KW - Felicity ratio
KW - Composite failure
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654852
DO - https://doi.org/10.1007/s10921-025-01319-1
SN - 0195-9298
VL - 45
IS - 1
SP - 1
EP - 19
PB - Springer Science and Business Media LLC
AN - OPUS4-65485
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dixneit, J.
A1 - Gibmeier, J.
A1 - Kromm, Arne
A1 - Schubnell, J.
A1 - Lang, F.
A1 - Loebich, F.
A1 - Carl, E.-R.
A1 - Ya, W.
T1 - Residual stress distribution of a large component manufactured by AM-DED-Arc from high-strength weld filler material X90
N2 - Currently, DED-Arc manufactured components are not covered by design guidelines, and design factors such as residual stress factors are not defined for such components. This hinders industrial use, especially for components with a remaining surface waviness required by industry. For the first time the stress state of a high-strength, low-alloy, large-scale DED-Arc component was characterised in the as-built state and after cutting off the component from the substrate plate. Complementary methods of residual stress analyses were applied to gain a holistic insight into the residual stress distributions of a thick-walled part. In the as-built state, direction-dependent and position-dependent tensile residual stresses were found for the component at the level of the yield strength of the part. The additive manufacturing strategy continuous spiral deposition has no significant influence on the residual stresses in bead threshold area compared to the residual stresses of the remaining component. For this case, bead threshold is no structural imperfection. By removing the part from the substrate plate, the residual stresses are significantly redistributed. Tensile residual stresses are then present at a moderate level. Compressive residual stresses were determined in the volume of the deposited material. The general consideration of ‘‘high’’ tensile residual stresses in such thick-walled components is rather conservative. Therefore, design guidelines should take the manufacturing condition into account.
KW - AM-DED-Arc
KW - Residual stress
KW - High strength steel
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655239
DO - https://doi.org/10.1177/03093247251406876
SN - 2041-3130
SP - 1
EP - 18
PB - SAGE
AN - OPUS4-65523
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -