TY - JOUR
A1 - Richter, Anja
A1 - Buchberger, G.
A1 - Stifter, D.
A1 - Duchoslav, J.
A1 - Hertwig, Andreas
A1 - Bonse, Jörn
A1 - Heitz, J.
A1 - Schwibbert, Karin
T1 - Spatial Period of Laser-Induced Surface Nanoripples on PET Determines Escherichia coli Repellence
N2 - Bacterial adhesion and biofilm formation on surfaces are associated with persistent microbial contamination, biofouling, and the emergence of resistance, thus, calling for new strategies to impede bacterial surface colonization. Using ns-UV laser treatment (wavelength 248 nm and a pulse duration of 20 ns), laser-induced periodic surface structures (LIPSS) featuring different submicrometric periods ranging from ~210 to ~610 nm were processed on commercial poly(ethylene terephthalate) (PET) foils. Bacterial adhesion tests revealed that these nanorippled surfaces exhibit a repellence for E. coli that decisively depends on the spatial periods of the LIPSS with the strongest reduction (~91%) in cell adhesion observed for LIPSS periods of 214 nm. Although chemical and structural analyses indicated a moderate laser-induced surface oxidation, a significant influence on the bacterial adhesion was ruled out. Scanning electron microscopy and additional biofilm studies
using a pili-deficient E. coli TG1 strain revealed the role of extracellular appendages in the bacterial repellence observed here.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Laser processing
KW - Polyethylene terephthalate
KW - Biofilm formation
KW - Cell appendages
KW - Biomimetic
KW - F pili
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537431
DO - https://doi.org/10.3390/nano11113000
VL - 11
IS - 11
SP - 3000
PB - MDPI
AN - OPUS4-53743
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Richter, S.
A1 - Horstmann, J.
A1 - Altmann, Korinna
A1 - Braun, U.
A1 - Hagendorf, C.
T1 - A reference methodology for microplastic particle size distribution analysis: Sampling, filtration, and detection by optical microscopy and image processing
N2 - Microplastic (MP) contamination in natural water circulation is a concern for environmental issues and human health. Various types of polymer materials have been identified and were detected in MP analytic test procedures. Beyond MP polymer type, particle size and form play a major role in water analysis due to possible negative toxicologic effects on flora and fauna. However, the correct quantitative measurement of MP size distribution over several orders of magnitude is strongly influenced by sample preparation, filtration materials and processes, and microanalytical techniques, as well as data acquisition and analysis. In this paper, a reference methodology is presented aiming at an improved quantitative analysis of MP particles. An MP analysis workflow is demonstrated including all steps from reference materials to sample preparation, filtration handling, and MP particle size distribution analysis. Background-corrected particle size distributions (1–1000 µm) have been determined for defined polyethylene (PE) and polyethylene terephthalate (PET) reference samples. Microscopically measured particle numbers and errors have been cross-checked with the total initial mass. In particular, defined reference MP samples (PE, PET) are initially characterized and applied to filtration experiments. Optical microscopy imaging on full-area Si filters with subsequent image analysis algorithms is used for statistical particle size distribution analysis. To quantify the effects of handling and filtration, several blind tests with distilled water are carried out to determine the particle background for data evaluation. Particle size distributions of PE and PET reference samples are qualitatively and quantitatively reproduced with respect to symmetry, and maximum and cut-off diameter of the distribution. It is shown that especially MP particles with a radius of >50 µm can be detected and retrieved with high reliability. For particle sizes <50 µm, a significant interference with background contamination is observed. Data from blank samples allows a correction of background contaminations. Furthermore, for enhanced sampling statistics, the recovery of the initial amount of MP will be qualitatively shown. The results are intended as an initial benchmark for MP analytics quality. This quality is based on statistical MP particle distributions and covers the complete analytic workflow starting from sample preparation to filtration and detection. Microscopic particle analysis provides an important supplement for the evaluation of established spectroscopic methods such as Fourier-transform infrared spectroscopy or Raman spectroscopy.
KW - Drinking water
KW - Filtration
KW - Microplastics detection
KW - Quality control
KW - Statistical particle distribution
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567625
DO - https://doi.org/10.1002/appl.202200055
SN - 2702-4288
SP - 1
EP - 10
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-56762
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Riedel, Soraya
A1 - Hülagü, Deniz
A1 - Bennet, Francesca
A1 - Carl, Peter
A1 - Flemig, Sabine
A1 - Schmid, Thomas
A1 - Schenk, J. A.
A1 - Hodoroaba, Vasile-Dan
A1 - Schneider, Rudolf
T1 - Electrochemical Immunomagnetic Ochratoxin A Sensing: Steps Forward in the Application of 3,3’,5,5’- Tetramethylbenzidine in Amperometric Assays
N2 - Electrochemical methods offer great promise in meeting the demand for user-friendly on-site devices for Monitoring important parameters. The food industry often runs own lab procedures, for example, for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with smart technologies. Enzyme-linked immunosorbent assays, with photometric detection of 3,3’,5,5’-tetramethylbenzidine (TMB),form a good basis for sensitive detection. To provide a straightforward approach for the miniaturization of the detectionstep, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry it was found that the TMB electrochemistry is strongly dependent on the pH and the electrode material. A stable electrode response to TMB could be achieved at pH 1 on gold electrodes. We created a smartphonebased, electrochemical, immunomagnetic assay for the detection of ochratoxin A in real samples, providing a solid basis forsensing of further analytes.
KW - Ochratoxin A
KW - Amperometry
KW - Cyclic voltammetry
KW - Electrochemistry
KW - Immunoassay
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530421
DO - https://doi.org/10.1002/celc.202100446
N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S.
VL - 8
IS - 13
SP - 2597
EP - 2606
AN - OPUS4-53042
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Risse, Kerstin
A1 - Nikiforidis, Constantinos V.
A1 - Morris, Imogen
A1 - Thünemann, Andreas
A1 - Drusch, Stephan
T1 - Regulating the heat stability of protein-phospholipid stabilised oil-water emulsions by changing the phospholipid headgroup or fatty acyl chain
N2 - Stabilising oil–water emulsions remains a central challenge across food, pharmaceutical and cosmetic applications. β-lactoglobulin (β-LG) and phospholipids (PLs) can act synergistically at oil-water interfaces: PLs adsorb rapidly, while β-LG forms a viscoelastic protein network that enhances long-term stability. However, competitive adsorption between proteins and PLs can disrupt interfacial structure. In addition, for commercial production, emulsions are often exposed to heat treatment during or after manufacture, for instance due to food safety requirements. Yet, the combined effects of PL structure and heat treatment on interfacial organisation and emulsion stability remain poorly understood.
Here we show that PL saturation and processing temperature jointly determine interfacial organisation, protein-PL interactions and emulsion stability. Using β-LG-PL emulsions, we combined ζ-potential measurements, small-angle X-ray scattering (SAXS), micro-differential scanning calorimetry (μDSC), X-ray diffraction and confocal laser scanning microscopy (CLSM) to link interfacial composition with functional stability.
Below the β-LG denaturation temperature (≤75 °C), saturated PLs promoted partial unfolding of β-LG at the interface without displacement, producing mixed protein-PL networks with enhanced viscoelasticity and stability. Unsaturated PLs displaced β-LG, yielding less elastic interfaces and promoting protein aggregation in the bulk. At ≥75 °C, increased hydrophobicity intensified protein-protein interactions irrespective of PL type.
Our findings reveal that saturated PLs shift the β-LG denaturation temperature upward by restricting molecular mobility, without preventing quaternary-level protein-protein interactions. Thermal denaturation, regardless of PL type, promoted interfacial multilayer formation at 90 °C. These results provide a mechanistic framework for tailoring emulsion stability via lipid saturation and processing temperature.
KW - Small-angle X-ray scattering
KW - SAXS
KW - Nanostructure
KW - Reference Method
KW - Colloid
KW - Nanoparticle
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648956
DO - https://doi.org/10.1016/j.jcis.2025.139530
SN - 0021-9797
VL - 705
SP - 1
EP - 25
PB - Elsevier Inc.
AN - OPUS4-64895
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodríguez-Sánchez, Noelia
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
A1 - Prinz, Carsten
A1 - Prieto-Laria, P.
A1 - Ruiz-Salvador, A.R.
A1 - Ballesteros, M.
T1 - Engineering a multivariate cobalt metal–organic framework for high photocatalytic activity: the impact of mixed ligands and metal incorporation in a visible light-driven heterogeneous photo-Fenton reaction for water treatment
N2 - Metal–organic frameworks (MOFs) have attracted increasing attention for the removal of organic pollutants in wastewater via photocatalysis. Here, we design a multivariate modification of ZIF-9 to tune its electronic properties for use in visible light photocatalysis. A controllable synthesis of ZIF-9 and its multivariate forms with the incorporation of copper and the 2-imidazolecarboxaldehyde (ica) ligand was carried out. The materials are tested for the removal of the model dye methylene blue (MB) by a heterogeneous photo-Fenton-like reaction at neutral pH and room temperature. Cu-ZIF-9-ica (UPO-3) shows high photocatalytic activity under both visible and ultraviolet A (UVA) light, achieving 94% MB degradation in 45 min, compared to 65% MB degradation in 120 min using bare ZIF-9. The study revealed a first-order rate constant of 0.0475 min−1 for Cu-ZIF-9-ica compared to 0.0088 min−1 for ZIF-9 under visible light. The improvement of the catalyst was clearly attributed to the co-incorporation of Cu and the ica ligand in the MOF, which reduces the band gap, in agreement with DFT calculations. Reproducibility and recyclability tests proved that Cu-ZIF-9-ica can be used for at least 3 cycles without a significant loss of efficiency, making it a promising material for the study and application of wastewater treatment.
KW - Metal-Organic Framework (MOF)
KW - Heterogeneous photo-Fenton
KW - ZIF-9
KW - Methylene Blue
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630797
DO - https://doi.org/10.1039/d4na00954a
SN - 2516-0230
VL - 7
IS - 8
SP - 2255
EP - 2265
PB - Royal Society of Chemistry
AN - OPUS4-63079
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodríguez-Sánchez, Noelia
A1 - Domínguez-Santos, J. Enrique
A1 - Bhattacharya, Biswajit
A1 - Prinz, Carsten
A1 - Canosa, Inés
A1 - Flores, Amando
A1 - Jiménez-Rodríguez, Antonia
A1 - Ruiz-Salvador, A. Rabdel
A1 - Emmerling, Franziska
A1 - Ballesteros, Menta
T1 - Mechanochemical synthesis of multivariate UPO-3 (Cu-ZIF-9-ica) MOF for inactivation of antibiotic-resistant bacteria and irrigation-quality water production via heterogeneous photo-Fenton catalysis
N2 - Water scarcity and pollution are critical global challenges, particularly in agriculture, the largest consumer of water. The development of sustainable, effective, and environmentally friendly disinfection methods is essential to address the risks posed by antibiotic-resistant bacteria and to ensure safe reuse of water for irrigation. In this study, we report the synthesis of the metal-organic framework (MOF) Universidad Pablo de Olavide-3 (UPO-3) via a mechanochemical approach, a scalable and sustainable method compared to traditional solvothermal synthesis. The resulting UPO-3/H2O2 system exhibits robust photocatalytic properties under visible light, achieving effective and broad-spectrum antibacterial activity. The disinfection efficiency of the catalyst was evaluated against Escherichia coli as a model of microbial pathogen in two saline matrices, considering the key parameters of the heterogeneous photo-Fenton process, including catalyst dosage, initial H2O2 concentration, and light irradiation. Notably, it inactivated two important virulent and antibiotic-resistant bacterial pathogens (Staphylococcus aureus and Pseudomonas aeruginosa). Furthermore, UPO-3 shows exceptional performance under real-world conditions, such as river water disinfection, achieving >5-log reduction of E. coli, fulfilling a critical criterion for Class A water reuse under Regulation (EU) 2020/741. These results highlight UPO-3 as a versatile and sustainable solution for water reuse, addressing water scarcity and advancing efforts to achieve United Nations Sustainable Development Goal 6.
KW - Water reuse
KW - Antibiotic-resistant bacteria
KW - Water disinfection
KW - Mechanochemical synthesis
KW - Metal organic framework
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639766
DO - https://doi.org/10.1016/j.chemosphere.2025.144610
SN - 0045-6535
VL - 386
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-63976
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodríguez-Sánchez, Noelia
A1 - Prinz, Carsten
A1 - Bienert, Ralf
A1 - Ballesteros, Menta
A1 - Ruiz Salvador, A. Rabdel
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
T1 - Mechanochemical ZIF-9 formation: in situ analysis and photocatalytic enhancement evaluation
N2 - Efficient treatment of persistent pollutants in wastewater is crucial for sustainable water management and environmental protection. This study addresses this challenge by investigating the mechanochemical synthesis and photocatalytic performance of ZIF-9, a cobalt-based zeolitic imidazolate framework. Using synchrotron-based powder X-ray diffraction, we provide real-time insights into the formation dynamics of ZIF-9 during mechanosynthesis. Our results show that mechanochemically synthesised ZIF-9 exhibits superior photocatalytic activity compared to its solvothermally prepared counterpart, achieving a 2-fold increase in methylene blue degradation rate. This research not only advances our understanding of the synthesis and properties of ZIF-9, but also demonstrates the potential of mechanochemical approaches in the development of high-performance, sustainably produced materials for water treatment and other environmental applications.
KW - MOFs
KW - ZIF
KW - Time-resolved in situ investigation
KW - Photocatalysis synchrotron X-ray powder diffraction
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641416
DO - https://doi.org/10.1039/D4MR00114A
SN - 2976-8683
VL - 2
IS - 1
SP - 116
EP - 126
PB - Royal Society of Chemistry (RSC)
CY - Cambridge
AN - OPUS4-64141
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rosen, Andrew S.
A1 - Gallant, Max
A1 - George, Janine
A1 - Riebesell, Janosh
A1 - Sahasrabuddhe, Hrushikesh
A1 - Shen, Jimmy-Xuan
A1 - Wen, Mingjian
A1 - Evans, Matthew L.
A1 - Petretto, Guido
A1 - Waroquiers, David
A1 - Rignanese, Gian-Marco
A1 - Persson, Kristin A.
A1 - Jain, Anubhav
A1 - Ganose, Alex M.
T1 - Jobflow: Computational Workflows Made Simple
N2 - We present Jobflow, a domain-agnostic Python package for writing computational workflows tailored for high-throughput computing applications. With its simple decorator-based approach, functions and class methods can be transformed into compute jobs that can be stitched together into complex workflows. Jobflow fully supports dynamic workflows where the full acyclic graph of compute jobs is not known until runtime, such as compute jobs that launch
other jobs based on the results of previous steps in the workflow. The results of all Jobflow compute jobs can be easily stored in a variety of filesystem- and cloud-based databases without the data storage process being part of the underlying workflow logic itself. Jobflow has been intentionally designed to be fully independent of the choice of workflow manager used to dispatch the calculations on remote computing resources. At the time of writing, Jobflow
workflows can be executed either locally or across distributed compute environments via an adapter to the FireWorks package, and Jobflow fully supports the integration of additional workflow execution adapters in the future.
KW - Automation
KW - Workflow
KW - Computational Materials Science
KW - Computations
KW - Software
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593104
DO - https://doi.org/10.21105/joss.05995
VL - 9
IS - 93
SP - 1
EP - 7
PB - The Open Journal
AN - OPUS4-59310
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rossi, Andrea
A1 - Alladio, Eugenio
A1 - Drobne, Damjana
A1 - Hodoroaba, Vasile-Dan
A1 - Jurkschat, Kerstin
A1 - Kononenko, Veno
A1 - Madbouly, Loay Akmal
A1 - Mrkwitschka, Paul
A1 - Novak, Sara
A1 - Radnik, Jörg
A1 - Saje, Špela
A1 - Santalucia, Rosangela
A1 - Sordello, Fabrizio
A1 - Pellegrino, Francesco
T1 - Development of a one-pot synthesis of rGO in water by optimizing Tour’s method parameters
N2 - Since its first synthesis in 2004, graphene has been widely studied and several different synthesis methods has been developed. Solvent exfoliation of graphite and the reduction of graphene oxide previously obtained through graphite oxidation are the most employed. In this work, we exploited synthesis conditions of a method usually employed for obtaining graphene oxide (the Tour’s method) for directly obtaining a very poorly oxidised material with characteristics like reduced graphene oxide. For the first time, a one-pot synthesis of reduced graphene oxide (rGO) is reported avoiding the use of a post-synthesis chemical or thermal reduction of the graphene oxide that requires further reagents, heat and time.
KW - Graphene
KW - 2D-materials
KW - Tour's method
KW - rGO
KW - One-pot synthesis
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611827
DO - https://doi.org/10.1038/s41598-024-73606-2
SN - 2045-2322
VL - 14
SP - 1
EP - 10
PB - Springer Nature
CY - London
AN - OPUS4-61182
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rossi, Andrea
A1 - Corrao, Elena
A1 - Alladio, Eugenio
A1 - Drobne, Damjana
A1 - Hodoroaba, Vasile-Dan
A1 - Jurkschat, Kerstin
A1 - Kononenko, Veno
A1 - Madbouly, Loay Akmal
A1 - Mrkwitschka, Paul
A1 - Yasamin, Nakhli
A1 - Novak, Sara
A1 - Radnik, Jörg
A1 - Saje, Špela
A1 - Santalucia, Rosangela
A1 - Sordello, Fabrizio
A1 - Pellegrino, Francesco
T1 - Multivariate optimization and characterization of graphene oxide via design of experiments and chemometric analysis
N2 - Controlling the structure and properties of graphene oxide (GO) remains a challenge due to the poor reproducibility of conventional synthetic protocols and limited understanding of parameter-property relationships. In this study, we present an integrated analytical framework that combines Design of Experiments (DoE) with chemometric modelling to systematically assess the effects of eight synthesis variables on GO’s physicochemical and functional features. A Plackett–Burman experimental design enabled efficient screening of synthesis conditions, while comprehensive characterization (spanning UV–Vis spectroscopy, XPS, SEM–EDX, TEM–EDX, and XRD) was coupled with multivariate tools (Principal Component Analysis and Multiple Linear Regression) to identify statistically significant correlations between synthetic inputs and material responses. Notably, we demonstrate that UV–Vis spectra can serve as a robust proxy for oxidation state, offering a rapid and accessible alternative to surface-sensitive methods. The approach yields a predictive analytical toolkit for guiding GO synthesis and highlights a generalizable strategy for the rational design of flat nanomaterials. This work supports reproducible, resource-efficient material development aligned with Safe and Sustainable by Design (SSbD) principles.
KW - Graphene oxide
KW - 2D-materials
KW - Design of Experiment
KW - Synthesis
KW - Chemometric analysis
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652576
DO - https://doi.org/10.1016/j.flatc.2025.100988
SN - 2452-2627
VL - 55
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-65257
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Roters, F.
A1 - Aslam, A.
A1 - Bai, Y.
A1 - Büschelberger, M.
A1 - Bulert, K.
A1 - Butz, A.
A1 - Hickel, Tilmann
A1 - Jogi, T.
A1 - Klitschke, S.
A1 - Martin, M.
A1 - Meyer, L.-P.
A1 - Morand, L.
A1 - Nahshon, Y.
A1 - Radtke, N.
A1 - Saikia, Ujjal
A1 - Trondl, A.
A1 - Wessel, A.
A1 - Zierep, P.
A1 - Helm, D.
T1 - StahlDigital: Ontology-Based Workflows for the Steel Industry
N2 - The innovative strength of the steel industry is based on the mastery of microstructure–property relationships. Digital workflows can largely contribute to this aim by making the complexity of workflows reproducible and their execution user independent. In this work, the tools and workflows developed in the project StahlDigital as part of the German MaterialDigital initiative are presented and application examples are provided. A steel ontology builds the
foundation for data collection and storage as well as for the semantic description of experimental and simulation data processing workflows. A dataspace powered by the Dataspace Management System (DSMS) digitally represents such workflows and manages data along them in a Findable, Accessible, Interoperable, Reusable manner aiming to derive new knowledge. Experimental data processed via DSMS can be further evaluated and used as input for simulation workflows. The simulations included in such workflows are run by the workflow system pyiron, which has been semantically extended in StahlDigital for this purpose.
KW - Steel
KW - Rolling
KW - Multiscale simulation
KW - Ontology
KW - Workflow
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627187
DO - https://doi.org/10.1002/adem.202402148
SN - 1527-2648
SP - 1
EP - 13
PB - Wiley VHC-Verlag
AN - OPUS4-62718
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Röhsler, Andreas
A1 - Sobol, Oded
A1 - Hänninen, H.
A1 - Böllinghaus, Thomas
T1 - In-situ ToF-SIMS analyses of deuterium re-distribution in austenitic steel AISI 304L under mechanical load
N2 - Hydrocarbons fuel our economy. Furthermore, intermediate goods and consumer products are often hydrocarbon-based. Beside all the progress they made possible, hydrogen-containing substances can have severe detrimental effects on materials exposed to them. Hydrogen-assisted failure of iron alloys has been recognised more than a century ago. The present study aims to providing further insight into the degradation of the austenitic stainless steel AISI 304L (EN 1.4307) exposed to hydrogen. To this end, samples were electrochemically charged with the hydrogen isotope deuterium (2H, D) and analysed by scanning electron microscopy (SEM), electron back-scatter diffraction (EBSD) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). It was found that deuterium caused a phase transformation from the original γ austenite into ε- and α’-martensite. Despite their low solubility for hydrogen, viz. deuterium, the newly formed phases showed high deuterium concentration which was attributed to the increased density of traps. Information about the behaviour of deuterium in the material subjected to external mechanical load was gathered. A four-point-bending device was developed for this purpose. This allowed to analyse in-situ pre-charged samples in the ToF-SIMS during the application of external mechanical load. The results indicate a movement of deuterium towards the regions of highest stress.
KW - ToF-SIMS
KW - Hydrogen
KW - Deuterium
KW - AISI 304L
KW - EBSD
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505142
DO - https://doi.org/10.1038/s41598-020-60370-2
VL - 10
IS - 1
SP - 3611
PB - Nature
AN - OPUS4-50514
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel H. E.
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - The kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations.
KW - MALDI-TOF MS
KW - Anionic polymerization
KW - β‐myrcene
KW - Kinetics
KW - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculations
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630900
DO - https://doi.org/10.1002/pi.6772
SN - 1097-0126
SP - 1
EP - 8
PB - Wiley
CY - New York, NY
AN - OPUS4-63090
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel HE
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
KW - Myrcene
KW - Anionic polymerization
KW - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculation
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636840
DO - https://doi.org/10.1002/pi.6772
SN - 0959-8103
SP - 1
EP - 8
PB - Wiley
AN - OPUS4-63684
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel HE
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
KW - Myrcene
KW - Anionic polymerization
KW - MALDI TOF MS
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649039
DO - https://doi.org/10.1002/pi.6772
SN - 0959-8103
SP - 1
EP - 8
PB - Wiley
AN - OPUS4-64903
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rühle, Bastian
A1 - Krumrey, Julian Frederic
A1 - Hodoroaba, Vasile-Dan
T1 - Workflow towards automated segmentation of agglomerated, non‑spherical particles from electron microscopy images using artificial neural networks
N2 - We present a workflow for obtaining fully trained artificial neural networks that can perform automatic particle segmentations of agglomerated, non-spherical nanoparticles from scanning electron microscopy images “from scratch”, without the need for large training data sets of manually annotated images. The whole process only requires about 15 minutes of hands-on time by a user and can typically be finished within less than 12 hours when training on a single graphics card (GPU). After training, SEM image analysis can be carried out by the artificial neural network within seconds. This is achieved by using unsupervised learning for most of the training dataset generation, making heavy use of generative adversarial networks and especially unpaired image-to-image translation via cycle-consistent adversarial networks. We compare the segmentation masks obtained with our suggested workflow qualitatively and quantitatively to state-of-the-art methods using various metrics. Finally, we used the segmentation masks for automatically extracting particle size distributions from the SEM images of TiO2 particles, which were in excellent agreement with particle size distributions obtained manually but could be obtained in a fraction of the time.
KW - Electron microscopy
KW - Neural networks
KW - Artificial intelligence
KW - Image segmentation
KW - Automated image analysis
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522454
DO - https://doi.org/10.1038/s41598-021-84287-6
VL - 11
IS - 1
SP - 4942
PB - Springer Nature
AN - OPUS4-52245
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sachse, René
A1 - Bernsmeier, D.
A1 - Schmack, R.
A1 - Häusler, I.
A1 - Hertwig, Andreas
A1 - Kraffert, K.
A1 - Nissen, J.
A1 - Kraehnert, R.
T1 - Colloidal bimetallic platinum–ruthenium nanoparticles in ordered mesoporous carbon films as highly active electrocatalysts for the hydrogen evolution reaction
N2 - Hydrogen features a very high specific energy density and is therefore a promising candidate for clean fuel from renewable resources. Water electrolysis can convert electrical energy into storable and transportable hydrogen gas. Under acidic conditions, platinum is the most active and stable monometallic catalyst for the hydrogen evolution reaction (HER). Yet, platinum is rare and needs to be used efficiently. Here, we report a synthesis concept for colloidal bimetallic platinum–ruthenium and rhodium–ruthenium nanoparticles (PtRuNP, RhRuNP) and their incorporation into ordered mesoporous carbon (OMC) films. The films exhibit high surface area, good electrical conductivity and well-dispersed nanoparticles inside the mesopores. The nanoparticles retain their size, crystallinity and composition during carbonization. In the hydrogen evolution reaction (HER), PtRuNP/OMC catalyst films show up to five times higher activity per Pt than Pt/C/Nafion® and PtRu/C/Nafion® reference catalysts.
KW - Ordered mesoporous carbon
KW - Bimetallic noble metal nanoparticles
KW - Platinum-ruthenium colloid
KW - Electrolysis
KW - Hydrogen evolution reaction
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506868
DO - https://doi.org/10.1039/C9CY02285F
SN - 2044-4753
VL - 10
IS - 7
SP - 2057
EP - 2068
PB - Royal Society of Chemistry
AN - OPUS4-50686
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sachse, René
A1 - Hodoroaba, Vasile-Dan
A1 - Kraehnert, R.
A1 - Hertwig, Andreas
T1 - Multilevel effective material approximation for modeling ellipsometric measurements on complex porous thin films
N2 - Catalysts are important components in chemical processes because they lower the activation energy and thus determine the rate, efficiency and selectivity of a chemical reaction. This property plays an important role in many of today’s processes, including the electrochemical splitting of water. Due to the continuous development of catalyst materials, they are becoming more complex, which makes a reliable evaluation of physicochemical properties challenging even for modern analytical measurement techniques and industrial manufacturing.
We present a fast, vacuum-free and non-destructive analytical approach using multi-sample spectroscopic ellipsometry to determine relevant material parameters such as film thickness, porosity and composition of mesoporous IrOx–TiOy films. Mesoporous IrOx–TiOy films were deposited on Si wafers by sol–gel synthesis, varying the composition of the mixed oxide films between 0 and 100 wt%Ir. The ellipsometric modeling is based on an anisotropic Bruggeman effective medium approximation (a-BEMA) to determine the film thickness and volume fraction of the material and pores. The volume fraction of the material was again modeled using a Bruggeman EMA to determine the chemical composition of the materials. The ellipsometric fitting results were compared with complementary methods, such as scanning electron microscopy (SEM), electron probe microanalysis (EPMA) as well as environmental ellipsometric porosimetry (EEP).
KW - Electrochemical catalysts
KW - Mixed metal oxide
KW - Multi-sample analysis
KW - Spectroscopic ellipsometry
KW - Thin mesoporous films
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551026
DO - https://doi.org/10.1515/aot-2022-0007
SN - 2192-8584
SN - 2192-8576
VL - 11
IS - 3-4 (Topical issue: Ellipsometry)
SP - 137
EP - 147
PB - De Gruyter
CY - Berlin
AN - OPUS4-55102
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sachse, René
A1 - Pfüger, Mika
A1 - Velasco-Vélez, Juan-Jesús
A1 - Sahre, Mario
A1 - Radnik, Jörg
A1 - Bernicke, Michael
A1 - Bernsmeier, Denis
A1 - Hodoroaba, Vasile-Dan
A1 - Krumrey, Michael
A1 - Strasser, Peter
A1 - Kraehnert, Ralph
A1 - Hertwig, Andreas
T1 - Assessing optical and electrical properties of highly active IrOx catalysts for the electrochemical oxygen evolution reaction via spectroscopic ellipsometry
N2 - Efficient water electrolysis requires highly active electrodes. The activity of corresponding catalytic coatings strongly depends on material properties such as film thickness, crystallinity, electrical conductivity, and chemical surface speciation. Measuring these properties with high accuracy in vacuum-free and nondestructive methods facilitates the elucidation of structure−activity relationships in realistic environments. Here, we report a novel approach to analyze the optical and electrical properties of highly active oxygen evolution reaction (OER) catalysts via spectroscopic ellipsometry (SE). Using a series of differently calcined, mesoporous, templated iridium oxide films as an example, we assess the film thickness, porosity, electrical resistivity, electron concentration, electron mobility, and interband and intraband transition energies by modeling of the optical spectra. Independently performed analyses using scanning electron microscopy, energy-dispersive X-ray spectroscopy, ellipsometric porosimetry, X-ray reflectometry, and absorption spectroscopy indicate a high accuracy of the deduced material properties. A comparison of the derived analytical data from SE, resonant photoemission spectroscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy with activity measurements of the OER suggests that the intrinsic activity of iridium oxides scales with a shift of the Ir 5d t2g sub-level and an increase of p−d interband transition energies caused by a transition of μ1-OH to μ3-O species.
KW - Spectroscopic ellipsometry
KW - Electrocatalysis
KW - Oxygen evolution reaction
KW - Mesoporous iridium oxide films
KW - Non-destructive ambient analysis
KW - Intrinsic OER activity
KW - Complementary methodology and metrology
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516288
DO - https://doi.org/10.1021/acscatal.0c03800
SN - 2155-5435
VL - 10
IS - 23
SP - 14210
EP - 14223
PB - American Chemical Society
AN - OPUS4-51628
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Saleh, Maysoon I.
A1 - Rühle, Bastian
A1 - Wang, Shu
A1 - Radnik, Jörg
A1 - You, Yi
A1 - Resch-Genger, Ute
T1 - Assessing the protective effects of different surface coatings on NaYF4:YB3+, Er3+, upconverting nanoparticles in buffer and DMEM
N2 - We studied the dissolution behavior of β NaYF4:Yb(20%), Er(2%) UCNP of two different sizes in biologically relevant media i.e., water (neutral pH), phosphate buffered saline (PBS), and Dulbecco’s modified Eagle medium (DMEM) at different temperatures and particle concentrations. Special emphasis was dedicated to assess the influence of different surface functionalizations, particularly the potential of mesoporous and microporous silica shells of different thicknesses for UCNP stabilization and protection. Dissolution was quantified electrochemically using a fluoride ion selective electrode (ISE) and by inductively coupled plasma optical emission spectrometry (ICP OES). In addition, dissolution was monitored fluorometrically. These experiments revealed that a thick microporous silica shell drastically decreased dissolution. Our results also underline the critical influence of the chemical composition of the aqueous environment on UCNP dissolution. In DMEM, we observed the formation of a layer of adsorbed molecules on the UCNP surface that protected the UCNP from dissolution and enhanced their fluorescence. Examination of this layer by X ray photoelectron spectroscopy (XPS) and mass spectrometry (MS) suggested that mainly phenylalanine, lysine, and glucose are adsorbed from DMEM. These findings should be considered in the future for cellular toxicity studies with UCNP and other nanoparticles and the design of new biocompatible surface coatings.
KW - Fluorescence
KW - Lifetime
KW - Method
KW - Quantification
KW - Stability
KW - Coating
KW - Surface chemistry
KW - Lanthanide
KW - Fluoride
KW - Electrochemistry
KW - ICP-OES
KW - Upconversion
KW - Nano
KW - Particle
KW - Aging
KW - Quality assurance
KW - Mass spectrometry
KW - XPS
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515984
DO - https://doi.org/10.1038/s41598-020-76116-z
SN - 2045-2322
VL - 10
IS - 1
SP - 19318-1
EP - 19318-11
PB - Springer Nature
CY - London
AN - OPUS4-51598
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -