TY - JOUR A1 - Wolf, M. E. A1 - Vickery, W. M. A1 - Swift-Ramirez, W. A1 - Arnold, A. M. A1 - Orlando, J. D. A1 - Schmidt, S. J. A1 - Liu, Y. A1 - Er, Jasmin A1 - Schusterbauer, Robert A1 - Ahmed, R. A1 - Nickl, Philip A1 - Radnik, Jörg A1 - Donskyi, Ievgen A1 - Sydlik, S. A. T1 - The Mitsunobu reaction for the gentle covalent attachment of biomolecules to graphene oxide N2 - Graphene oxide (GO) has emerged as a promising biomaterial as it is easily and cheaply synthesized, strong, cytocompatible, osteoinductive, and has a well-characterized aqueous degradation pathway. It is also a great substrate for functionalization with biomolecules such as proteins, peptides, and small molecules that can enhance or add bioactivity. Covalent chemical linkages as opposed to typical noncovalent association methods are preferable so that the biomolecules do not quickly diffuse away or face replacement by other proteins, which is critical in long time scale applications like bone regeneration. However, covalent chemistry tends to carry a drawback of harsh reaction conditions that can damage the structure, conformation, and therefore function of a delicate biomolecule like a protein. Here, the Mitsunobu reaction is introduced as a novel method of covalently attaching proteins to graphene oxide. It features gentle reaction conditions and has the added benefit of utilizing the plentiful basal plane alcohol functionalities on graphene oxide, allowing for high yield protein functionalization. The amino acid Glycine (G), the protein bovine serum albumin (BSA), and the small molecule SVAK-12 are utilized to create the three Mitsunobu Graphene (MG) materials G-MG, BSA-MG, and SVAK-MG that demonstrate the wide applicability of this functionalization method. KW - Graphene oxide KW - Mitsunobu reaction KW - Covalent attachment KW - Bovine serum albumin KW - Macrophage polarization KW - Osteogenesis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630483 DO - https://doi.org/10.1016/j.carbon.2025.120221 VL - 238 SP - 1 EP - 15 PB - Elsevier Ltd. AN - OPUS4-63048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chemello, Giovanni A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - XPS–SEM/EDS Tandem Analysis for the Elemental Composition of Functionalized Graphene Nanoplatelets N2 - Over the past decade, energy-dispersive X-ray spectrometry (EDS) with scanning electron microscopy (SEM) has advanced to enable the accurate analysis of light elements such as C, N, or O. For this reason, EDS is becoming increasingly interesting as an analytical method for the elemental analysis of functionalized graphene and could be an attractive alternative to Xray photoelectron spectroscopy (XPS), which is considered the most important method for elemental analysis. In this study, comparative XPS and EDS investigations under different excitation conditions are carried out on commercially available powders containing graphene particles with different morphologies. The slightly different XPS/HAXPES and EDS results can be explained by the different information depths of the methods and the functionalization of the particle surfaces. For the material with smaller graphene particles and higher O/C ratios, all methods reported a lower O/C ratio in pellets compared with the unpressed powder samples. This clearly shows that sample preparation has a significant influence on the quantification results, especially for such a type of morphology. Overall, the study demonstrates that EDS is a reliable and fast alternative to XPS for the elemental quantification of functionalized graphene particles, provided that differences in the information depth are taken into account. Particle morphology can be examined in parallel with quantitative element analysis, since EDS spectrometers are typically coupled with SEM, which are available in a huge number of analytical laboratories. KW - Graphene oxide KW - SEM/EDS KW - XPS/HAXPES KW - Elemental composition KW - Functionalization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647294 DO - https://doi.org/10.1021/acsomega.5c07830 SN - 2470-1343 SP - 1 EP - 7 PB - American Chemical Society (ACS) AN - OPUS4-64729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Sahre, Mario A1 - Zurutuza, Amaia A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Standardized Chemical Composition Analysis of Graphene Oxide Flakes with SEM/EDS and XPS Works Reliably N2 - Suspensions of graphene-related 2D materials (GR2M) are broadly used for further applications like printable electronics. The reliable quantification of the composition of graphene-related 2D materials as liquid suspensions is still a challenging task, which can hinder the commercialisation of the products. Specific parameters to be measured are defined, e.g. the oxygen-to-carbon (O/C) concentration ratio, the trace metal impurities, or the functional groups present, but reference protocols are still missing. One of the central methods for the quantification is X-ray photoelectron spectroscopy (XPS) as a rather expensive method. Therefore, the development of cheaper alternatives is highly desired. One attractive alternative of XPS is energy-dispersive spectroscopy (EDS) which is usually coupled with scanning electron microscopy (SEM). This combination is one of the most widely used methods in analytical laboratories. In this contribution the results of a systematic study on the capability of SEM/EDS to reliably quantify the O/C ratio in a well-defined and well-characterized graphene oxide material are presented. The robustness of the SEM/EDS results obtained at various measurement conditions (various excitation energies) is tested by comparing the results to the established XPS analysis, which has been carried out on the same samples. It is demonstrated that for samples prepared by drop-casting on a substrate, both surface-sensitive XPS analysis and bulk-characterising EDS result in very similar elemental composition of oxygen and carbon for thick spots. Further, the effect of untight deposited material enabling co-analysis of the (silicon) substrate, is evaluated for both methods, XPS and EDS. The last results clearly show the influence of the substrate on the analysis of the results and stressed out the importance of the sample preparation. KW - EDS KW - Light elements KW - XPS/HAXPES KW - Graphene oxide KW - Quantification KW - Standardisation PY - 2025 DO - https://doi.org/10.1093/mam/ozaf048.267 VL - 31 IS - 7 SP - 531 EP - 532 PB - Oxford Aacademic AN - OPUS4-63792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Reusable data: putting the “Arr” in FAIR N2 - This talk demonstrates how to apply FAIR principles to data from actual scientific investigations. The reasons and practical benefits of FAIR data are highlighted. Several levels of reusability are discussed, i.e. the “trust me”-level, the “I’ll not need to repeat my measurement”-level, and the “you’ll not need to repeat my measurements”-level. Practical FAIR datafiles are explored and their information content highlighted. T2 - Reusability of Scientific Data for Matter CY - Online meeting DA - 13.11.2025 KW - Methodology KW - Metadata KW - FAIR KW - Reusability KW - X-ray scattering KW - Traceability PY - 2025 AN - OPUS4-65309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul T1 - Standardized Chemical Characterisation of Graphene Oxide Flakes by X-Ray Photoelectron Spectroscopy and Energy-Dispersive X-Ray Spectroscopy N2 - Reliable quantification of the chemical composition of graphene-related 2D materials as powders and liquid suspensions is a challenging task. Analytical methods such as XPS, ICP-MS, TGA and FTIR are recommended to be used in ongoing projects at standardisation bodies. The specific parameters to be measured are also defined, e.g. the oxygen-to-carbon (O/C) concentration ratio, the trace metal impurities, or the functional groups present [1]. In this contribution, for the first time, the results of a systematic study on the capability of SEM/EDS to reliably quantify the O/C ratio in a well-defined and well-characterized graphene oxide material [2] are presented. It is expected that the quantitative EDS analysis of light elements emitting characteristic X-ray lines below 1 keV to be provided with significantly larger measurement uncertainties than the analysis of elements with an atomic number of 11 (Na) or above [3]. The robustness of the SEM/EDS results obtained at various measurement conditions (various excitation energies) is tested by comparing the results to the established XPS analysis [4], which has been carried out on the same samples. A crucial step in sample preparation from liquid suspension with graphene oxides flakes onto a substrate for analysis with both XPS and EDS. It is demonstrated that if a closed and enough thick drop-cast deposited spot is succeeded to be deposited on a substrate, both surface-sensitive XPS analysis and bulk-characterising EDS result in very similar elemental composition of oxygen and carbon. Hence, theoretical, expected O/C atomic ratio values for pure graphene oxide of ~0.5 [1] are achieved (with both methods), see Figure 1. Further, the effect of untight deposited material enabling co-analysis of the (silicon) substrate, is evaluated for both methods, XPS and EDS. To note that all the EDS results in this study have been quantified standardless. The results of this study demonstrate the reliability of the reference measurement protocol for SEM/EDS to be introduced into ISO/DTS 23359, including the dedicated sample preparation, particularly for the cases when the concentration of the GO flakes in stock liquid suspension is low. Further, also the consideration of this GO material as one of the very few available as a commercial material on the market as the very first GO reference material with regard to its morphology as well as chemical composition. Both the standard measurement procedure and the candidate reference material will immensely contribute to characterise reliably the chemical composition of graphene-related 2D materials with SEM/EDS as one of the most widely used methods in analytical laboratories T2 - EMAS 2025 Workshop CY - Mataró, Spain DA - 11.05.2025 KW - Advanced Materials KW - Graphene KW - Chemical Quantification KW - EDX KW - XPS PY - 2025 AN - OPUS4-64082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul T1 - Wire-print procedure for accurate morphological and Chemical characterization of graphene-related 2D-materials N2 - One of the biggest challenges in the physico-chemical characterization of particulate nanomaterials pertains to the sample preparation. Particularly the imaging methods require suitable deposition of the sample on a substrate. ‘Suitable’ sample preparation of a particulate (nano)material on a substrate means to make visible the constituent particles to a microscopy technique able to analyze the nanoscale (AFM, SEM, TEM, etc). The particles deposited on a substrate either directly as a powder or from liquid suspension must be ideally isolated (de-agglomerated), without particle losses, homogeneously distributed in a high density of particles per substrate area for efficient analysis, with good statistics of the counted particles. Various sample preparation approaches to meet the latter requirements have been reported in the literature, e.g. electrospray, substrate surface treatment, embedding the particulate material and polishing the cross-section, or addition of ligands to the suspended nanostructures to enhance their hydrophilicity [1], [2], [3], [4]. In this study we have systematically tested the efficacy of a new deposition procedure for graphene-related 2D materials (GR2M’s) from liquid suspension onto a substrate for quantitative analysis of their size and shape distribution with electron microscopy. The technique is an extension of the conventional drop-casting method, and we have designated it “wire-print” deposition. It consists of two steps, first one being usual drop-casting on a copper substrate and second one involving a thin copper wire with a sub-mm diameter being dipped into the deposited droplet and retracted with a corresponding half-spherical droplet attached on its tip and final deposition of this entire nL-amount of suspension onto e.g. a silicon wafer for microscopical, detailed analysis. The result of 11 series of such a wire-print deposition for a graphene-based ink is shown in Figure 1 (labeled A-L), where various conditions (treatment of the starting suspension) have been experimented with a repetition of up to 10 times per condition, all together 86 spots on a silicon wafer of 10 mm x 10 mm. The result of one series of 8 repeated wire-print depositions is shown in Figure 2, where the deposited spots are visualized with SEM. Note the weak presence of coffee-rings, irregular spot shape, and presence of agglomerates. The results for the measured flake size distribution expressed as ECD (equivalent circular diameter) are represented in Fig. 3 for all the eight depositions. Both the mean value of the 8 ECD distributions and the total number of flakes deposited in each spot show a variance in the range of 17% and 22%, respectively, see Table 1. In the context of accurate analysis of such challenging complex materials these numbers can be considered as excellent and demonstrate the high benefit of the wire-print deposition for accurate morphological measurements on GR2M’s. T2 - Microscopy and Microanalysis 2025 CY - Salt Lake City, UTAH, USA DA - 27.07.2025 KW - Sample preparation KW - Graphene KW - Electron Microscopy KW - Morphology PY - 2025 AN - OPUS4-64083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Waqfi, R. A. A1 - Khan, C. J. A1 - Irving, O. J. A1 - Matthews, Lauren A1 - Albrecht, T. T1 - Crowding Effects during DNA Translocation in Nanopipettes N2 - Quartz nanopipettes are an important emerging class of electric single-molecule sensors for DNA, proteins, their complexes, as well as other biomolecular targets. However, in comparison to other resistive pulse sensors, nanopipettes constitute a highly asymmetric environment and the transport of ions and biopolymers can become strongly directiondependent. For double-stranded DNA, this can include the characteristic translocation time and tertiary structure, but as we show here, nanoconfinement can also unlock capabilities for biophysical and bioanalytical studies at the single-molecule level. To this end, we show how the accumulation of DNA inside the nanochannel leads to crowding effects, and in some cases reversible blocking of DNA entry, and provide a detailed analysis based on a range of different DNA samples and experimental conditions. Moreover, using biotin-functionalized DNA and streptavidinmodified gold nanoparticles as target, we demonstrate in a proof-of-concept study how the crowding effect, and the resulting increased residence time in nanochannel, can be exploited by first injecting the DNA into the nanochannel, followed by incubation with the nanoparticle target and analysis of the complex by reverse translocation. We thereby integrate elements of sample processing and detection into the nanopipette, as an important conceptual advance, and make a case for the wider applicability of this device concept. KW - DNA translocation KW - Transport KW - Resistive-pulse sensing KW - Nanopores KW - Nanopipettes KW - Crowding KW - Confinement PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630448 DO - https://doi.org/10.1021/acsnano.5c01529 SN - 1936-086X VL - 19 IS - 17 SP - 1 EP - 9 PB - ACS Publications AN - OPUS4-63044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pellegrino, F. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - Unveiling Order in Graphene Oxide Synthesis Through A Design of Experiment and Chemometric Strategy Based on Tour’s Method N2 - Graphene oxide (GO), a derivative of graphene containing oxygen functional groups, shows significant potential for a wide range of applications due to its unique electrical, mechanical, and chemical properties. Traditional synthesis methods, such as Tour's method, often rely on trial-and-error, leading to variations in product quality and yield. To address these challenges, we applied Design of Experiments (DoE) to systematically investigate the effects of key synthesis parameters, including reaction temperature, reaction time, and oxidant concentration. We identified the most significant factors influencing GO characteristics using a Plackett-Burman design and chemometric analysis. Our results highlight that the oxidation level is the most critical factor, impacting outcomes observed through various characterization techniques, such as UV-Vis spectroscopy and X-Ray Diffraction. Principal Component Analysis (PCA) and Multiple Linear Regression (MLR) provided insights into the synthetic parameters most strongly affecting material properties. While some findings aligned with expectations, others were counterintuitive. For instance, oxidation temperature had a minimal effect on the final material characteristics and may not need to be prioritized in the synthesis process. On the other hand, stirring was found to enhance the homogeneity of the material and promote more uniform oxidation. This study demonstrates the effectiveness of DoE in the controlled production of graphene oxide, offering a reliable framework for manufacturing high-quality GO tailored to specific applications. By minimizing time and resource consumption, this approach is increasingly relevant in the context of materials science, which demands higher quality, safety and sustainability standards. T2 - Joint Regulatory Risk Assessors Summit – Advancing Safety & Sustainability Assessments of Advanced Materials CY - Paris, France DA - 19.06.2025 KW - Graphene oxide KW - Chemometry KW - UV-Vis KW - XRD KW - XPS KW - EDX PY - 2025 UR - https://macrame-project.eu/macrame-meetings-workshops/jointrras/#Agenda AN - OPUS4-63676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Xing, Na A1 - Er, Jasmin A1 - Vidal, Ricardo M. A1 - Khadka, Sandhya A1 - Schusterbauer, Robert A1 - Rosentreter, Maik A1 - Etouki, Ranen A1 - Ahmed, Rameez A1 - Page, Taylor A1 - Nickl, Philip A1 - Bawadkji, Obida A1 - Wiesner, Anja A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Ludwig, Kai A1 - Trimpert, Jakob A1 - Donskyi, Ievgen T1 - Scalable covalently functionalized black phosphorus hybrids for broadspectrum virucidal activity N2 - At the onset of viral outbreaks, broad-spectrum antiviral materials are crucial before specific therapeutics become available. We report scalable, biodegradable black phosphorus (BP) hybrids that provide mutation-resilient virucidal protection. BP sheets, produced via an optimized mechanochemical process, are covalently functionalized with 2-azido-4,6-dichloro- 1,3,5-triazine to form P=N bonds. Fucoidan, a sulfated polysaccharide with intrinsic antiviral activity, and hydrophobic chains are then incorporated to achieve irreversible viral deactivation. The material exhibits strong antiviral inhibition and complete virucidal activity against multiple viruses, including recent severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants. It maintains high biocompatibility, remains effective against viral mutations, and is shelf stable for at least five month. The combination of biodegradability, scalable synthesis, and synergistic antiviral and virucidal mechanisms establishes BP-conjugates as a new class of highly efficient antivirals. They offer a broad spectrum antiviral solutions that could bridge the gap between antiviral medicines and general antiseptics. KW - Black phosphorus KW - Antiviral materials KW - Functionalization KW - Biodegradability KW - Sheets PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652941 DO - https://doi.org/10.48550/arXiv.2510.12854 SN - 2331-8422 SP - 1 EP - 22 PB - Cornell University CY - Ithaca, NY AN - OPUS4-65294 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - The role of Critical Raw Materials in Advanced Materials for the Energy Transition N2 - The energy transition needs advanced materials, especially for batteries, solar cells, and fuel cells. Therefore, critical raw materials are necessary. In this presentation the use of critcal raw materials and strategies for the optimisation of their use are discussed. T2 - Critical Raw Material Workshop during VAMAS Annual Meeting CY - Teddington, United Kingdom DA - 17.09.2025 KW - Advanced solar cells KW - Iridium oxide KW - Aerogels KW - Advanced carbon materials PY - 2025 AN - OPUS4-64290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Mühlbauer, Michaela A1 - Rossi, Andrea A1 - Pellegrino, Francesco A1 - Zurutuza, Amaia A1 - Radnik, Jörg A1 - Meier, Florian A1 - Hodoroaba, Vasile-Dan T1 - Morphological Analysis of Graphene Oxide by Scanning Electron Microscopy and Correlative Field-flow Fractionation Coupled with Multi-angle Light Scattering N2 - In this paper graphene related 2D materials (GR2M) arre investigated by centrifugal field flow fractioning (CF3) and SEM. Three materials were selected as case studies (CS): graphene „HD-G (CS I), graphene oxide UniTo“ (CS II), and graphene oxide „Graphenea“ (CS III). For CS I particles were evaluated as constituent particles in agglomerates, for the other two materials only isolated (non aggregated/agglomerated) flakes were considered for determination of the area equivalent circular diameter (ECD). Size analysis of all three materials was carried out by CF3 coupled with MALS (Multi-Angle Light Scattering). For evaluation, it was found that the data obtained was best suited to a disc model. Results are in good agreement when compared to the sizes obtained before CF3 analysis. CS II material is too heterogenous to accurately determine flake size by imaging. CF3 coupled with MALS enables to assess fractions within the highly heterogenous material of CS II. Imaging of the material in CS III after CF3 measurement indicates that the procedure is non-destructive. This could not be verified for the CS‘s I & II As a next step we plan to analyse the fractionated samples by imaging them within a SEM wet-cell. KW - 2D Materials KW - SEM KW - Centrifugal field flow fractionation (CF3) KW - Imaging KW - Size distribution PY - 2025 DO - https://doi.org/10.1093/mam/ozaf048.222 VL - 31 IS - 7 SP - 442 EP - 443 PB - Oxford Academic AN - OPUS4-63804 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Methodologies implemented to measure key properties of graphene and other 2D materials N2 - The key properties and suitable measurement methods for the characterization of graphene-related 2D materials are presented. A case study will be discussed about the chemical characterisation of functionalised graphene used in inks along the production chain. T2 - European-African Graphene Workshop CY - Parys, South Africa DA - 26.11.2025 KW - X-ray photoelectron spectroscoyp KW - Raman spectroscopy KW - Defects KW - Surface Chemistry PY - 2025 AN - OPUS4-64959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Liaison Report ISO/TC 229 Nanotechnology for ISO/TC 202 Microbeam Analysis and vice-versa N2 - The liaison between the ISO technical committees TC 229 Nanotechnologies and TC 202 Microbeam analysis is described in detail with highlight on the projects under development and published since 2024 and which involve input /knowledge from ISO/TC 202. T2 - 32nd Plenary Meeting of ISO/TC 202 Microbeam Analysis CY - London, United Kingdom DA - 28.10.2025 KW - Nanotechnology KW - Microabeam analysis KW - Standardisation KW - ISO PY - 2025 AN - OPUS4-64551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Energy-Dispersive X-Ray Spectrometry (EDS) on GR2Ms for Routine/Standardized Elemental Analysis N2 - The elemental analysis of solid matter by means of the Energy-Dispersive X-Ray Spectrometry (EDS) is meanwhile posible as a quick (seconds!) and more and more accurate analysis via standardsless (instantaneous) quantification. The sensitivity & quantification accuracy for light elements (C, O,..) has significantly increased in the recent years. The availability via table-top SEMs with incorporated EDS is also enhanced. Further, the EDS analysis at an SEM is well-standardized, see ISO/TC 202 Microbeam Analysis & VAMAS/ TWA 37 Quantitative Microstructural Analysis in good liaisonships with ISO/TC 229 Nanotechnologies. It is demostrated that key parameters such as oxygen-to-carbon atomic-% ratio and impurities can be realibly measured, with XPS as a reference method. Various EDS spectrometers and analysis conditions are tested and the validity of the EDS quantification of an ionic liquid of well-defined chemical composition is demonstrated. Next steps are: launch of a corresponding VAMAS interlaboratory comparison and discussions within ISO/TC 202 Microbeam Analysis. T2 - 32nd Plenary Meeting of ISO/TC 202 Microbeam Analysis CY - London, United Kingdom DA - 28.10.2025 KW - GR2M KW - EDS KW - Quantification KW - XPS KW - Light elements KW - 2D materials PY - 2025 AN - OPUS4-64553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Methodologies implemented to measure key properties of graphene and other 2D materials - EDX N2 - The elemental analysis of solid matter by means of the Energy-Dispersive X-Ray Spectrometry (EDS) is meanwhile posible as a quick (seconds!) and more and more accurate analysis via standardsless (instantaneous) quantification. The sensitivity & quantification accuracy for light elements (C, O,..) has significantly increased in the recent years. The availability via table-top SEMs with incorporated EDS is also enhanced. It is demostrated that key parameters such as oxygen-to-carbon atomic-% ratio and impurities can be realibly measured, with XPS as a reference method. Various EDS spectrometers and analysis conditions are tested and the validity of the EDS quantification of an ionic liquid of well-defined chemical composition is demonstrated. T2 - Advanced Materials Graphene: The implementation of SbD and SSbD CY - Parys, South Africa DA - 26.11.2025 KW - Light elements KW - EDS KW - Quantification KW - Oxygen-to-carbon ratio KW - XPS KW - Graphene-realted 2D materials PY - 2025 AN - OPUS4-64943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Energy Dispersive X Ray Spectrometry (EDS) on GR2Ms for Routine/Standardized Elemental Analysis N2 - The elemental analysis of solid matter by means of the Energy-Dispersive X-Ray Spectrometry (EDS) is meanwhile posible as a quick (seconds!) and more and more accurate analysis via standardsless (instantaneous) quantification. The sensitivity & quantification accuracy for light elements (C, O,..) has significantly increased in the recent years. The availability via table-top SEMs with incorporated EDS is also enhanced. Further, the EDS analysis at an SEM is well-standardized, see ISO/TC 202 Microbeam Analysis & VAMAS/ TWA 37 Quantitative Microstructural Analysis in good liaisonships with ISO/TC 229 Nanotechnologies. It is demostrated that key parameters such as oxygen-to-carbon atomic-% ratio and impurities can be realibly measured, with XPS as a reference method. Various EDS spectrometers and analysis conditions are tested and the validity of the EDS quantification of an ionic liquid of well-defined chemical composition is demonstrated. Next steps are: launch of a corresponding VAMAS interlaboratory comparison and discussions within ISO/TC 202 Microbeam Analysis. T2 - ISO/TC 229 Nanotechnologies Meeting Week CY - Stockholm, Sweden DA - 19.05.2025 KW - Graphene-related 2D materials (GR2M) KW - Energy-Dispersive X-Ray Spectrometry (EDS) KW - Elemental analysis KW - Quantification KW - ISO/TC 229 Nanotechnologies PY - 2025 AN - OPUS4-63190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Report VAMAS/TWA 37 "Quantitative Microstructural Analysis" & Liaison with ISO/TC 202 "Microbeam Analysis" N2 - The progress in activities on Quantitative MicroStructural Analysis under VAMAS/TWA 37 is reviewed. Particularly the liaison with the new projects within the ISO technical committee TC 202 Microbeam Analysis is presented and discussed with respect to the identification and launching corresponding VAMAS projects. The ongoing projects "Development of guidelines for reproducible TEM specimen preparation by FIB processing", "Measurement of dislocation density in metallic materials by Transmission Electron Microscope (TEM)", "Repeatability of high angular resolution electron backscatter diffraction (HR-EBSD) analysis for elastic strain measurements", "Measurement of grain size and distribution of nanocrystalline nickel by using Transmission Kikuchi Diffraction (TKD) in SEM" and the just started project "Evaluation Method of Surface Layer Quality of TEM Specimen Prepared by focused Ion Beam Processing" are presented in detail. T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 50th Steering Committee Meeting CY - London, United Kingdom DA - 15.09.2025 KW - VAMAS KW - Interlaboratory comparison KW - Microbeam Analysis KW - Electron Microscopy KW - ISO/TC 202 KW - Sample preparation PY - 2025 AN - OPUS4-64231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Deep Insights into Functionalised Nanoparticles with Photoelectron Spectroscopy N2 - Modern instrumentation X-ray photoelectron instrumentation combines soft and hard X-rays. Additonally, in the last years methods were developed for the analysis of the measurement data to elucidate the composition and thickness of coatings of nanoparticles. In this presentation four examples will be presented: quantum dots, silica-coated iron-oxide nanoparticles, mixed Fe-Ni-O nanoparticles and amine-functionalized silica nanoparticles. These different nanoparticles are used for displays, for biomedicine, for water splitting, and as additives and fillers. T2 - United Kingdom Surface Analysis Forum Meeting 2025 CY - Teddington, UK DA - 15.07.2025 KW - Simulation KW - Oxygen evolution reaction KW - Transmission electron microscopy KW - Quantitative nuclear magnetic resonance (qNMR) PY - 2025 AN - OPUS4-63733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Analysis of Nanoparticles N2 - The determination of the thickness and composition of the coating is crucial for the understanding of the properties of nanoparticles. Four different approaches will be presented: (i) numerical methods, (ii) descriptive formulae, (iii) the simulation of spectra with Monte-Carlo methods, and (iv) inelastic background analysis. The advantages and limits of these methods will be discussed. T2 - XPS Workshop CY - Teddington, United Kingdom DA - 14.07.2025 KW - Numerical simulation KW - Emperical formulae KW - Simulation KW - Inelastic background analysis PY - 2025 AN - OPUS4-63732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Interlaboratory comparisons for validated measurements of the surface chemistry of nanomaterials N2 - Interlaboratory comparisons are essential tools for validating new protocols or methods. The properties of advanced materials are largely determined by surface chemistry. Using a VAMAS interlaboratory comparison on the surface functionalization of GR2DM, it is explained what insights can be gained from such a comparison.” T2 - Nanomesure France Journee technique CY - Paris, France DA - 04.11.2025 KW - VAMAS KW - Functionalized graphene KW - X-ray photoelectron spectroscopy PY - 2025 AN - OPUS4-65002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altmann, Korinna A1 - Wimmer, Lukas A1 - Alcolea-Rodriguez, Victor A1 - Waniek, Tassilo A1 - Wachtendorf, Volker A1 - Matzdorf, Kay A1 - Ciornii, Dmitri A1 - Fengler, Petra A1 - Milczewski, Frank A1 - Otazo-Aseguinolaza, Itziar A1 - Ferrer, Manuel A1 - Bañares, Miguel A. A1 - Portela, Raquel A1 - Dailey, Lea Ann T1 - Quality-by-design and current good practices for the production of test and reference materials for micro- and nano-plastic research N2 - Understanding the environmental and human health impacts of micro- and nanoplastic pollutants is currently a high priority, stimulating intensive methodological research work in the areas of sampling, sample preparation and detection as well as intensive monitoring and testing. It is challenging to identify and quantify microplastics in complex organic matrices and concepts for nanoplastic detection are still in their infancy. All analytical techniques employed in studying micro- and nanoplastics require suitable reference materials for validation measurements, with requirements as diverse as the analytical tools used, ranging from different polymer types, size distributions and shapes of the material to the concentrations employed in different experimental set ups (ng to g amounts). The aim of this manuscript is to outline current good practices for small-scale laboratory production and characterization of suitable test and reference materials. The focus is placed on top-downfragmentation methods as well as bottom-up precipitation methods. Examples using polyethylene, polypropylene, polystyrene and polyethylene terephthalate with size distribution classes of mainly 10–1000, 1–10 and <1 μm particles will be provided. Experiences and suggestions on how to produce well-characterized micro- and nano-plastics for internal research needs will ensure that studies using the materials have robust and informative outcomes. KW - Mmicroplastics KW - Nanoplastics KW - Reference materials KW - Standard validation method PY - 2025 DO - https://doi.org/10.1016/j.jhazmat.2025.139595 SN - 0304-3894 VL - 497 SP - 1 EP - 20 PB - Elsevier B.V. AN - OPUS4-63958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cosimi, Andrea A1 - Stöbener, Daniel D. A1 - Nickl, Philip A1 - Schusterbauer, Robert A1 - Donskyi, Ievgen A1 - Weinhart, Marie T1 - Interfacial nanoengineering of hydrogel surfaces via block copolymer self-assembly N2 - Synthetic polymer hydrogels are valuable matrices for biotransformations, drug delivery, and soft implants. While the bulk properties of hydrogels depend on chemical composition and network structure, the critical role of interfacial features is often underestimated. This work presents a nanoscale modification of the gel−water interface using polymer brushes via a straightforward “grafting-to” strategy, offering an alternative to more cumbersome “grafting-from” approaches. Functional block copolymers with photoreactive anchor blocks are successfully self-assembled and UV-immobilized on hydrogel substrates despite their low solid content (<30 wt %). This versatile technique works on both bulk- and surface-immobilized hydrogels, demonstrated on poly(hydroxypropyl acrylate), poly(N-isopropylacrylamide), and alginate gels, allowing precise control over grafting density. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry revealed a homogeneous bilayered architecture. By “brushing-up”, the hydrogels’ interface can be tailored to enhance protein adsorption, improve cell adhesion, or impair the diffusive uptake of small molecules into the bulk gels. This effective interfacial nanoengineering method is broadly applicable for enhancing hydrogel performance across a wide range of applications. KW - Brushing-up KW - Benzophenone KW - LCTS-type polymer KW - Poly(glycidyl ether) (PGE) KW - Fibroblast adhesion KW - XPS KW - ToF-SIMS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652966 DO - https://doi.org/10.1021/acsami.4c18632 SN - 1944-8244 VL - 17 IS - 6 SP - 10073 EP - 10086 PB - American Chemical Society (ACS) CY - Washington, DC AN - OPUS4-65296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Standardized Chemical Composition Analysis of Graphene Oxide Flakes with SEM/EDS and XPS Works Reliably N2 - Reliable quantification of the chemical composition of graphene-related 2D materials (GR2M) as powders and liquid suspensions is a challenging task. Analytical methods such as XPS, ICP-MS, TGA and FTIR are recommended in projects at standardization bodies. The parameters to be measured are also defined, e.g. the oxygen-to-carbon (O/C) concentration ratio, the trace metal impurities, or the functional groups present. In this contribution, for the first time, the capability of SEM/EDS to reliably quantify the O/C ratio in a well-characterized graphene oxide (GO) material is evaluated. The robustness of the SEM/EDS results under various measurement conditions is tested by comparison to the established XPS analysis. A crucial step is the sample preparation from liquid suspension with GO flakes onto a substrate for analysis with both EDS and XPS. It is demonstrated that if a closed and enough thick drop-cast spot is deposited on a substrate, both surface-sensitive XPS analysis and bulk-characterizing EDS result in very similar elemental composition of oxygen and carbon. Hence, the theoretical, expected O/C atomic ratio values for pure GO of ~0.5 are achieved with both methods. Further, the effect of untight deposited material causing co-analysis of the silicon substrate, is evaluated for both methods, XPS and EDS. Note that all the EDS results in this study have been quantified standardless. The standard measurement procedure including the GO material considered here as a candidate reference material will make a significant contribution to analyse reliably the chemical composition of GR2M with SEM/EDS as one of the most widely used methods in analytical laboratories. T2 - Graphene Week 2025 CY - Vicenza, Italy DA - 22.09.2025 KW - EDX KW - Graphene-related 2D materials KW - O/C ratio KW - Standardisation KW - Samle preparation KW - XPS PY - 2025 AN - OPUS4-64261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Sahre, Mario A1 - Corrao, Elena A1 - Pellegrino, Francesco A1 - Hodoroaba, Vasile-Dan T1 - Wire-Print as a Sample Preparation Procedure Suitable for Accurate Morphological Characterization of Constituent Particles for Graphene-Related 2D-Materials N2 - In this study we have systematically tested the efficacy of a new deposition procedure for graphene-related 2D materials (GR2M’s) from liquid suspension onto a substrate for quantitative analysis of their size and shape distribution with electron microscopy. The technique is an extension of the conventional drop-casting method, and we have designated it “wire-print” deposition. It consists of two steps, first one being usual drop-casting on a copper substrate and second one involving a thin copper wire with a sub-mm diameter being dipped into the deposited droplet and retracted with a corresponding half-spherical droplet attached on its tip and final deposition of this entire nL-amount of suspension onto e.g. a silicon wafer for microscopical, detailed analysis. 11 series of such a wire-print deposition for a graphene-based ink have been considered, whereby various conditions (treatment of the starting suspension) have been experimented with a repetition of up to 10 times per condition, all together 86 spots on a silicon wafer of 10 mm x 10 mm. The evaluation of one series of 8 repeated wire-print depositions reveal that the deposited spots are visualized with SEM. The weak presence of coffee-rings, irregular spot shape, and presence of agglomerates should be noticed. Both the mean value of the 8 ECD distributions and the total number of flakes deposited in each spot show a variance in the range of 17% and 22%, respectively. In the context of accurate analysis of such challenging complex materials these numbers can be considered as excellent and demonstrate the high benefit of the wire-print deposition for accurate morphological measurements on GR2M’s. KW - Sample preparation KW - Imaging KW - 2D materials KW - Morphology KW - Size distribution PY - 2025 DO - https://doi.org/10.1093/mam/ozaf048.219 VL - 31 IS - 7 SP - 436 EP - 437 PB - Oxford Academic AN - OPUS4-63821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Habibimarkani, Heydar A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - John, Elisabeth T1 - Probing Surface Changes in Fe–Ni Oxide Nanocatalysts with a ToF-SIMS-Coupled Electrochemistry Setup and Principal Component Analysis N2 - Understanding catalyst surface dynamics under operating conditions is essential for improving electrocatalytic performance. Here, we present a novel approach combining electrochemical treatment with contamination-free transfer to Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), followed by principal component analysis (PCA), to probe surface and interfacial changes in Ni–Fe oxide nanoparticles stabilized by polyvinylpyrrolidone (PVP) during the oxygen evolution reaction (OER). The surface analysis at three distinct treatment stages revealed distinct chemical fingerprints across pristine nanoparticles, after exposure to 1 M KOH electrolyte, and after cyclic voltammetry treatment. The results highlight a progressive transition from ligand-rich to ligand-depleted interfaces, with PVP-related fragments dominant in the early stages and metal- and electrolyte-derived species emerging after activation. Complementary ToF-SIMS analysis of electrolyte deposited on Si wafers after each treatment step confirms the concurrent leaching of PVP and Fe–Ni-based fragments during OER. These findings underscore the dynamic nature of catalyst–electrolyte interfaces and demonstrate a robust strategy for monitoring surface-sensitive chemical changes associated with the nanoparticles, especially during the initial cycles of the OER. KW - Fe-Ni oxide KW - Nanocatalysts KW - ToF-SIMS KW - Electrochemistry KW - PCA (principal component analysis) KW - OER PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652667 DO - https://doi.org/10.1021/acs.analchem.5c03894 SN - 0003-2700 SP - 1 EP - 8 PB - American Chemical Society (ACS) AN - OPUS4-65266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - Nano and Advanced Materials - Competences at BAM and perspectives N2 - This presentation gives an overview about the competencies and the characterization possibilities of nanoparticles at BAT, based on this the development of the OECD TG 125 at BAM. It further describes research activities at BAM concerning the characterization of nanoparticles and the way to the digital representation of these characterization possibilities. It concludes with the challenges of a digital product passport (DPP) for nanomaterial based products and the need of a digital materials passport (DMP). Finally, the activities of BAM are presented which address the former mentioned challenges from ESRP and DPP. T2 - Austausch Helmholtz Hereon / Digipass & BAM CY - Berlin, Germany DA - 07.07.2025 KW - Nanomaterials KW - ESPR KW - DPP KW - Nano KW - Advanced Materials PY - 2025 AN - OPUS4-64974 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Campos de Oliveira, Paula A1 - Markötter, Henning A1 - Zhang, Wen A1 - Eddah, Mustapha A1 - Widjaja, Martinus Putra A1 - Remacha, Clément A1 - Bruno, Giovanni T1 - Enhanced image segmentation of refractories using synchrotron X-ray computed tomography and machine learning techniques N2 - The microstructure of refractory materials is complex, featuring a variety of mineral phases, agglomerates, defects, and controlled porosity. The behavior of refractories at high temperatures adds another layer of complexity, as phase transitions and particle rearrangements can strongly affect their properties. To analyze such intricate microstructure, advanced imaging techniques such as Synchrotron X-ray Computed Tomography (SXCT) allow detailed 3D visualization and quantification of features up to 1 μm. However, the intricacy of these microstructures makes phase identification (known as image segmentation) in digital images a challenging process. X-ray images often contain noise and image artifacts, making the analysis more difficult. Therefore, this work describes image segmentation and artifact reduction methods to characterize refractories using X-ray imaging. We studied refractory ceramics used in the aerospace industry, primarily composed of fused silica. For image segmentation, the traditional approach of greyscale thresholding was compared with machine learning. Greyscale thresholding relies on predefined algorithms to assign phases based on intensity values. In contrast, machine learning extracts patterns from large datasets, enabling more adaptive and accurate segmentation. By combining high-resolution SXCT and machine learning analysis algorithms, we successfully segmented previously uncharacterized 3D microstructural key features of refractories, including agglomerates, grain boundaries, pore size distribution and interconnectivity. Compared to traditional methods, the machine learning-enhanced segmentation presented a more accurate quantification of porosity and defects. The integration of advanced imaging techniques with machine learning segmentation significantly improves the characterization of refractory materials, providing a more precise understanding of the relationship between microstructure and material performance, supporting the development of innovative industrial solutions. T2 - The 19th Biennial International Technical Conference on Refractories (UNITECR 2025) CY - Cancún, Mexiko DA - 27.10.2025 KW - Synchrotron X-ray Tomography KW - Machine learning KW - Image segmentation KW - Ceramics KW - Refractories PY - 2025 SP - 478 EP - 481 AN - OPUS4-64803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ren, L. A1 - Pollard, A. A1 - Hodoroaba, Vasile-Dan T1 - Measurement of Lateral Size of Graphene Oxide Flakes by SEM - An Update of the VAMAS TWA 41 Project P13 N2 - The progress of the VAMAS interlaboratory comparison Project P13 "Lateral size of graphene oxide flakes by SEM" within the Technical Working Area 41 "Graphene and Related 2D Materials" is presented. The challenges at sample preparation on substrates for accurate measurement and image analysis as well as two different image analysis approaches, containing exact guidance how to measure the main descriptors for the lateral size measurement of the imaged graphene oxide flakes with Scanning Electron Microscopy are described. Discrepancies are explained. The inclusion of the results into the corresponding ISO technical specification CD/TS 23879 is also discussed and planned, in relation with the AFM part. T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 50th Steering Committee Meeting CY - London, United Kingdom DA - 15.09.2025 KW - VAMAS KW - Interlaboratory comparison KW - Electron microscopy KW - Lateral size KW - Graphene oxide flakes PY - 2025 UR - https://www.vamas.org/twa41/documents/2023_vamas_twa41_project13_GO_SEM.pdf AN - OPUS4-64228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul A1 - Hodoroaba, Vasile-Dan T1 - Wire-Print as a Novel Sample Preparation Approach for Accurate Morphological Characterization of Constituent Particles of Graphene-Related 2D-Materials N2 - Graphene and graphene-oxide (GO) are used for instance in catalysis, biomedical applications, in inks and as composite materials. To ensure product quality and safe-by-design principles within the various application fields, the commercial material must be characterized and specified through well-known and standardized procedures. The accurate morphological characterization of 2D materials is a challenging task, requiring careful sample preparation on a substrate either as a powder or from liquid suspension. These must be isolated, homogeneously distributed, with good statistics of the counted particles. Various sample preparation approaches have been reported in the literature, e.g. electrospray, substrate surface treatment, embedding the particulate material and polishing the cross-section, or addition of ligands to the suspended nanostructures. In this study, a novel deposition procedure for graphene-related 2D materials (GR2Ms) was systematically tested for its efficacy. The quantitative analysis of the size and shape distribution of the materials was conducted using electron microscopy and was successfully tested in XPS and EDS experiments. The technique is an extension of the conventional drop-casting method and has been designated "wire-print" deposition. The result of such a wire-print deposition for a graphene-based suspension is shown in Figure, where various treatment conditions have been tested with a repetition of up to 10 times per condition, all together 86 spots on a silicon wafer of 10 mm². T2 - Graphene Week 2025 CY - Vicenza, Italy DA - 22.09.2025 KW - Graphene-related 2D materials (GR2M) KW - Sample peparation KW - Imaging KW - Electron Microscopy KW - Wire-print deposition method PY - 2025 AN - OPUS4-64248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Florian, Camilo T1 - Optical thickness-profiling for fs-laserinduced superficial amorphization and oxide removal on silicon N2 - Amorphization and re-crystallization of polished silicon wafers cut in <111> and <100> orientation were studied after irradiation by single Ti:sapphire femtosecond laser pulses (790 nm, 30 fs) using optical imaging, topographic characterization, and transmission electron microscopy. Spectroscopic imaging ellipsometry (SIE) enabled fast data acquisition at multiple wavelengths and provided experimental data for calculating the amorphous layer thickness profiles with lateral resolution in the micrometer and vertical resolution in the nanometer range based on a thin-film layer model including the topmost native oxide. For a radially Gaussian shaped laser beam and at moderate peak laser fluences above the melting but below the ablation threshold, laterally parabolic amorphous layer profiles with maximum thicknesses of some tens of nanometers were quantitatively derived. Moreover, the threshold fluence of the native oxide removal was quantified. At laser peak fluences closely below the ablation threshold of silicon, SIE is capable to reveal even the laser-induced removal and formation of the native oxide covering the Si wafers under ambient air conditions. The accuracy of these all-optical, non-destructive SIE-based layer thickness assessments is verified experimentally through high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (STEM-EDX). Along with topographic information obtained by atomic force microscopy (AFM), a comprehensive picture of the oxide removal and superficial re-solidification of silicon after local melting by femtosecond laser pulses can be drawn. T2 - E-MRS Spring Meeting 2025 CY - Strasbourg, France DA - 26.05.2025 KW - Femtosecond laser KW - Laser-induced amorphization KW - Native oxide layer KW - Spectroscopic imaging ellipsometry KW - Transmission electron microscopy PY - 2025 AN - OPUS4-63275 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Bacterial adhesion on ultrashort pulse laser processed surfaces ― more than size matters! N2 - Bacterial biofilms are aggregates of bacterial cells, often attached to a surface and enclosed by a self-produced extracellular matrix which confers increased stress tolerance and resistance to cleaning. Biofilm formation leads to biofouling which gives rise to high costs in numerous technical settings due to biocorrosion and biodegradation. However, biofilms can also be attractive for industrial settings such as wastewater treatment systems or for soil bioremediation processes. Hence, the control of bacterial adhesion to a surface is of major concern. Surface topography strongly influences bacterial adhesion. Therefore, one promising way to achieve bacteria-guiding surfaces lies in the contactless and aseptic large-area laser processing of technical surfaces. We used short and ultrashort pulsed laser systems to generate different surface textures, mainly high-spatial-frequency and low-spatial-frequency laser-induced periodic surface structures, LIPSS (HFSL and LFSL), on Ti, Ti-alloy, steel, and polymers (PET and PE). Pristine (polished) and laser processed samples were subjected to bacterial adhesion experiments with two different Escherichia coli strains and Staphylococcus aureus as test organisms. The bacterial strains differed in their cell wall structure (grampositive vs. gramnegative strains), in size, shape, the occurrence of cell appendages, and in their biofilm forming capabilities. Adhesion patterns were analyzed microscopically and compared regarding the respective test strain and surface topography. Our results revealed that adhesion behavior strongly depends not only on the material’s topography and chemistry, but also on the specific bacterial strain, the presence of cell appendages, and ambient growth conditions. T2 - 13th International Conference on Photoexcited Processes and Applications, ICPEPA-13 CY - Lecce, Italy DA - 14.09.2025 KW - Biofilm KW - Bacterial adhesion KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses PY - 2025 AN - OPUS4-64166 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martínez, E. A1 - Lejeune, N. A1 - Frechilla, J. A1 - Porta-Velilla, L. A1 - Forneau, E. A1 - Angurel, L. A. A1 - de la Fuente, G. F. A1 - Bonse, Jörn A1 - Silhanek, A. V. A1 - Badía-Majós, A. T1 - Laser engineered architectures for magnetic flux manipulation on superconducting Nb thin films N2 - Custom shaped magnetic flux guiding channels have been fabricated on superconducting Nb thin films by laser nanopatterning of their surface. Preferential pathways are defined by suitable combination of imprinted anisotropic pinning domains through laser-induced periodic surface structures (LIPSS). Generated by the selective energy deposition of femtosecond UV laser pulses, quasi-parallel ripple structures are formed under optimized irradiation conditions. On average, each domain is formed by grooves with a lateral period of 260–270 nm and a depth about 80 nm. By combination of scanning and transmission electron microscopy, magneto-optical imaging, and conductive atomic force microscopy techniques, we conclude that the boundaries of the LIPSS-covered domains play a prominent role in the magnetic flux diversion process within the film. This is confirmed by dedicated modeling of the flux dynamics, combined with the inversion of the magneto-optical signal. The created metasurfaces enable control of the flux penetration process at the microscale. KW - Laser-induced periodic surface structures (LIPSS) KW - Magnetic flux KW - Magneto-optical imaging (MOI) KW - Critical current density PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611243 UR - https://www.sciencedirect.com/science/article/pii/S0169433224019287 DO - https://doi.org/10.1016/j.apsusc.2024.161214 SN - 1873-5584 (Online) SN - 0169-4332 (Print) VL - 679 SP - 1 EP - 12 PB - Elsevier AN - OPUS4-61124 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wonneberger, R. A1 - Gräf, S. A1 - Bonse, Jörn A1 - Wisniewski, W. A1 - Freiberg, K. A1 - Hafermann, M. A1 - Ronning, C. A1 - Müller, F. A. A1 - Undisz, A. T1 - Tracing the Formation of Femtosecond Laser-Induced Periodic Surface Structures (LIPSS) by Implanted Markers N2 - The generation of laser-induced periodic surface structures (LIPSS) using femtosecond lasers facilitates the engineering of material surfaces with tailored functional properties. Numerous aspects of their complex formation process are still under debate, despite intensive theoretical and experimental research in recent decades. This particularly concerns the challenge of verifying approaches based on electromagnetic effects or hydrodynamic processes by experiment. In the present study, a marker experiment is designed to conclude on the formation of LIPSS. Well-defined concentration depth profiles of 55Mn+- and 14N+-ions were generated below the polished surface of a cast Mn- and Si-free stainless steel AISI 316L using ion implantation. Before and after LIPSS generation, marker concentration depth profiles and the sample microstructure were evaluated by using transmission electron microscopy techniques. It is shown that LIPSS predominantly formed by material removal through locally varying ablation. Local melting and resolidification with the redistribution of the material occurred to a lesser extent. The experimental design gives quantitative access to the modulation depth with a nanometer resolution and is a promising approach for broader studies of the interactions of laser beams and material surfaces. Tracing LIPSS formation enables to unambiguously identify governing aspects, consequently guiding the path to improved processing regarding reproducibility, periodicity, and alignment. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser processing KW - Ion implantation KW - Transmission Electron Microscopy (TEM) KW - Stainless steel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623990 DO - https://doi.org/10.1021/acsami.4c14777 SN - 1944-8244 (Print) SN - 1944-8252 (Online) VL - 17 IS - 1 SP - 2462 EP - 2468 PB - ACS Publications AN - OPUS4-62399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Laser Nanotexturierung von Metalloberflächen zur Reduktion von Reibung und Verschleiß N2 - Die Reduktion von Reibung und Verschleiß in technischen Systemen bietet ein großes Potenzial zur Reduktion von CO2-Emissionen. Dieser Beitrag diskutiert die Erzeugung und tribologische Charakterisierung von Ultrakurzpuls-generierten Nanostrukturen auf Metallen (Stahl, Titan). Besonderes Augenmerk wird dabei auf die Rolle der laserinduzierten Oxidschicht im Zusammenspiel mit verschleißreduzierenden Additiven in ölbasierten Schmiermitteln gerichtet. T2 - Online Abendvortrag beim AWT Härterei- und Werkstoffkreis Bodensee der Arbeitsgemeinschaft Wärmebehandlung + Werkstofftechnik e.V. CY - Online meeting DA - 16.01.2025 KW - Additive KW - Laser-induzierte periodische Nanostrukturen KW - Reibungsreduktion KW - Verschleißreduktion PY - 2025 AN - OPUS4-62432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voss, Heike T1 - Morphology and regularity of high-spatial frequency laser-induced periodic surface structures (HSFL) on titanium materials N2 - Titanium and its alloys are known to allow the straightforward laser‐based manufacturing of ordered surface nanostructures, so‐called high spatial frequency laser‐induced periodic surface structures (HSFL). These structures exhibit sub‐100 nm spatial periods – far below the optical diffraction limit. The resulting surface functionalities are usually enabled by both, topographic and chemical alterations of the nanostructured surfaces. For exploring these effects, HSFL were processed on different titanium materials (bulk, film) upon irradiation with near‐infrared ps‐laser pulses (1030 nm wavelength, ≈ 1 ps pulse duration) under different laser scan processing conditions. Here we extend our previous work on chemical analyses of HSFL on titanium materials towards a more detailed morphological and topographical surface characterization. For that, scanning electron and atomic force microscopic images are subjected to a regularity analysis using our self-developed ReguΛarity software. The regularity of the HSFL is assessed with respect to the influences of sample- and laser-related parameters, as well as the imaging method used. T2 - 13th International LIPSS Workshop CY - Enschede, Netherlands DA - 29.10.2025 KW - Laser-induced periodic surface structures (LIPSS) KW - Titanium KW - Ultrashort laser pulses KW - Laser processing PY - 2025 AN - OPUS4-64631 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Laser Nanotexturierung von Metalloberflächen zur Reduktion von Reibung und Verschleiß N2 - Die Reduktion von Reibung und Verschleiß in technischen Systemen bietet ein großes Potenzial zur Reduktion von CO2-Emissionen. Dieser Beitrag diskutiert die Erzeugung und tribologische Charakterisierung von Ultrakurzpuls-generierten Nanostrukturen auf Metallen (Stahl, Titan). Besonderes Augenmerk wird dabei auf die Rolle der laserinduzierten Oxidschicht im Zusammenspiel mit verschleißreduzierenden Additiven in ölbasierten Schmiermitteln gerichtet. T2 - Internationale Bodensee Fachtagung „Wärmebehandlung und Oberflächentechnik zur Verbesserung von Tribologie und Verschleissbeständigkeit" CY - Feldkirch, Austria DA - 20.03.2025 KW - Additive KW - Laser-induzierte periodische Nanostrukturen KW - Reibungsreduktion KW - Verschleißreduktion PY - 2025 AN - OPUS4-62757 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Generation and characterization of anisotropic nanostructures using ultrashort pulsed lasers N2 - The lecture gives an overview of the generation and characterization of anisotropic nanostructures using ultrashort pulsed laser radiation. Special attention will be paid to the phenomenon of so-called laser-induced periodic surface structures (LIPSS) on various materials. One focus will be on dielectrics and the dynamics of nanostructure formation. Further examples of bulk nanostructures from the literature will be discussed. T2 - 8th UKP-Workshop: Ultrafast Laser Technology CY - Aachen, Germany DA - 08.04.2025 KW - Laser-induced Periodic Surface Structures (LIPSS) KW - Dielectrics KW - Surface Nanostructures KW - Volume Nanostructures PY - 2025 AN - OPUS4-62947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Ultrafast optical probing of laser-induced formation of periodic surface nanostructures N2 - Laser-induced Periodic Surface Structures (LIPSS, ripples) are a universal phenomenon and can be generated in a contactless, single-step process on almost any type of solid upon irradiation with intense laser pulses. They represent a (quasi-)periodic modulation of the surface topography in the form of a linear grating and are typically formed in a “self-ordered” way in the focus of a coherent laser beam. Thus, they are often accompanying laser material processing applications. The structural sizes of LIPSS typically range from several micrometers down to less than 100 nanometers – far beyond the optical diffraction limit – while their orientations exhibit a clear correlation with the local polarization direction of the laser radiation. From a theoretical point of view, a controversial debate has emerged during the last decades, whether LIPSS originate from electromagnetic effects (seeded already during the laser irradiation) – or whether they emerge from matter-reorganization processes (distinctly after the laser irradiation). From a practical point of view, however, LIPSS represent a simple and robust way for the nanostructuring of solids that allows creating a wide range of different surface functionalities featuring applications in optics, tribology, medicine, energy technologies, etc. The presentation provides an overview of current theories on LIPSS and the quest to achieve ever smaller surface nanostructures. The historical development of the fundamental ideas behind LIPSS is presented, together with experimental approaches that make it possible to distinguish between the various LIPSS formation scenarios. Time-resolved experimental methods are required to investigate the dynamics of their formation. The presentation focuses on ultrafast time-resolved optical (pump-probe) techniques that can be used for localized point measurements or microscopic imaging, utilizing the reflection, diffraction, or coherent scattering of the probe radiation at the emerging LIPSS, while simultaneously capturing information about rapid melting, ablation, and solidification phenomena. However, given the sub-micrometric spatial periods of LIPSS, their analysis using optical radiation employed in far-field techniques remained a challenge. Therefore, short wavelengths of the probe beam in the UV range or even below are required to overcome the diffraction limit imposed in the optical spectral range. Fourth-generation light sources, namely short-wavelength (XUV or X-ray) short-pulse free-electron lasers (FELs), offer new and fascinating possibilities for resolving laser-induced structure formation on surfaces in the sub-micrometer to nanometer range and in time domains from picoseconds to several nanoseconds with a resolution in the sub-picosecond regime. On laser-irradiated semiconductor surfaces, this unique spatio-temporal resolution enables the detection of early signs of coherent/plasmonic electromagnetic scattering effects, followed by the excitation of hydrodynamic capillary waves – providing new insights into the above-mentioned debate. Recent experiments at the European XFEL used fs-time-resolved small-angle X-ray scattering (fs-SAXS) and even fs-time-resolved grazing incidence small-angle X-ray scattering (fs-GISAXS), combined with grazing-incidence diffraction (fs-GID), to reveal the dynamics of the formation of nanometric LIPSS on metals. T2 - CINSaT Herbstkolloquium 2025 CY - Kassel, Germany DA - 05.11.2025 KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Pump-probe measurements KW - Free-electron laser KW - Small angle X-ray scattering (SAXS) PY - 2025 AN - OPUS4-64633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hassenstein, Christian T1 - Robotergestützte Ultraschallprüfung von Objekten mit komplexen Geometrien N2 - Durch den Einsatz moderner digitaler Design- und Fertigungsmethoden wachsen einerseits die Komplexität von Bauteilen, andererseits der Bedarf an Informationen über deren Qualität und Zustand. Damit steigen auch die Anforderungen an die zerstörungsfreie Prüfung, die im Zuge von ZfP 4.0 automatisierte und flexible, innovative Prüfmethoden erfordert. Das gilt insbesondere für Objekte, deren Oberflächengeometrien über plane Flächen und eindimensionale Krümmungen hinausgehen. Um zu zeigen, wie eine Ultraschallprüfung von Objekten mit komplexer Oberflächengeometrie realisiert werden kann, wurde an der BAM eine roboterbasierte Demonstratoranlage entwickelt. Dabei führt ein Roboterarm einen Array-Prüfkopf in Tauchtechnik senkrecht über die Prüffläche. Die dafür erforderliche Prüfbahn kann entweder anhand der CAD-Geometrie oder mithilfe einer Punktewolke der Prüffläche, die vorab mit einem am Roboter angebrachten Laser-Profilometer erfasst wird, ermittelt werden. Zur Erhöhung der Genauigkeit werden der Lasersensor und der Ultraschallprüfkopf automatisiert mit dafür entwickelten Routinen am Roboter eingemessen. Durch bildgebende Verfahren und eine automatische Auswertung der Bilder kann die in Tauchtechnik auftretende Brechung des Schallbündels an der Prüfteiloberfläche berücksichtigt werden, was die ortsrichtige Rekonstruktion von Anzeigen aus dem Prüfteilinneren bzw. der Rückwand ermöglicht. Durch Rückführung der Anzeigen in ein gemeinsames Koordinatensystem entsteht eine 3D-Rekonstruktion des Prüfteils. Der vorliegende Beitrag stellt die Demonstratoranlage und die angewendeten Methoden im Detail vor und nennt Anwendungsbeispiele. T2 - DGZfP Jahrestagung 2025 CY - Berlin, Germany DA - 26.05.2025 KW - Ultraschall KW - Robotik KW - Turbinenschaufel KW - Wanddicke KW - Defekterkennung PY - 2025 AN - OPUS4-63417 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voss, Heike T1 - ReguΛarity - A free software for the objective quantification of the regularity of periodic surface structures generated by femtosecond laser irradiation N2 - The precise laser-based surface structuring on the micro- and nanoscale allows to create functional properties for innovative applications, e.g., in medicine, optics and biology. Among the various types of surface structures, laser-induced periodic surface structures (LIPSS) are characterized by their versatility and the relatively simple manufacturing process. However, the fabrication of highly regular LIPSS patterns remains challenging. The systematic investigation of LIPSS formation, as well as of the resulting functional properties requires a precise evaluation of the surface morphology, especially with regard to periodicity and regularity. Existing quantification methods such as Fast Fourier Transformation (FFT) tend to lack automation and objectivity, especially when dealing with large data sets and multi-scale structures. Although automated approaches exist with the Gini coefficient and the P³S method, their limited availability restricts a broader scientific use. We therefore introduce ReguΛarity as an innovative open-source software solution for objective, rapid and reproducible evaluation of structured surfaces concerning their regularity. In order to provide comprehensive surface morphological analysis, our software uses advanced image-processing techniques and integrates the already developed tools such as P³S method, Gini coefficient, FFT analysis, and the calculation of DLOA (Dispersion of LIPSS Orientation Angle). The software allows to evaluate any relevant image format as provided, e.g., by standard scanning electron micrographs. An intuitive PyQt5-based interface, enhanced by multi-threading capabilities, facilitates efficient data processing. Interactive features such as region-of-interest selection and plotting provide flexible adaptation to diverse applications. ReguΛarity offers a robust analysis tool that will contribute to the further development of precise laser-based surface structuring and to the optimization of the desired functional properties in both research and industry. T2 - 13th International Conference on Photoexcited Processes and Applications, ICPEPA-13 CY - Lecce, Italy DA - 14.09.2025 KW - Laser-induced periodic surface structures (LIPSS) KW - Laser processing KW - Fourier transformation KW - Regularity PY - 2025 AN - OPUS4-64176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rahner, E. T1 - From nightmare to numbers - A novel software tool for objective regularity analysis of LIPSS N2 - The precise laser-based surface structuring on the micro- and nanoscale allows for the creation of functional properties for innovative applications, e.g., in medicine, optics and biology. Among the various types of surface structures, laser-induced periodic surface structures (LIPSS) are distinguished by their versatility and the comparatively simple manufacturing process. Nevertheless, the fabrication of highly regular LIPSS patterns remains challenging. The systematic investigation of LIPSS formation, as well as of the resulting functional properties demands accurate and objective evaluation of surface morphology, especially regarding periodicity and regularity. Existing quantification methods such as Fast Fourier Transformation (FFT) tend to lack automation and objectivity, especially when dealing with large data sets and multi-scale structures. Although automated approaches, such as those based on the Gini coefficient or the P³S method, have been proposed, their limited availability hinders a broader scientific use. To overcome these limitations, we introduce ReguΛarity, a novel, freely available Python-based software tool featuring a graphical user interface for automated and quantitative assessment of regularity in period and (quasi-)periodic surface patterns including LIPSS. The software processes microscopic images obtained from optical, scanning electron microscopy (SEM), or atomic force microscopy (AFM), combining image segmentation with one- and two-dimensional Fourier analyses (1D-FT, 2D-FT), phase evaluation, and gradient-based orientation determination to facilitate a comprehensive regularity analysis of (quasi-)periodic surface patterns with spatial periods Λ. Regularity is quantified by the newly proposed five-dimensional regularity tuple R comprising the normalized spread of spatial periods from 2D-FT, the normalized local variation of the dominant spatial period from 1D-FT, the Gini coefficient G, the Dispersion of the LIPSS Orientation Angle (DLOA), and the mean phase deviation. The demonstration of the software’s capabilities is achieved by comparing idealized sinusoidal test patterns with SEM micrographs of fs-laser-generated LIPSS on stainless steel (AISI 316L) and aluminum alloy (AlMg5). This comparison highlights ReguΛarity’s objective differentiation between varying levels of structural regularity. The software facilitates high-throughput analysis and data-driven optimization in laser surface engineering processes. T2 - 13th International LIPSS Workshop CY - Enschede, Netherlands DA - 29.10.2025 KW - Laser-induced periodic surface structures (LIPSS) KW - Surface functionalization KW - Fourier transform KW - Gini coefficient PY - 2025 AN - OPUS4-65047 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gräf, S. T1 - Ion marker implantation as key to understand the formation of femtosecond LIPSS on steel N2 - Ultrashort laser (fs-laser) pulses can be used to generate laser-induced periodic surface structures (LIPSS, ripples) on different types of materials. A variety of potential applications of these grating-like LIPSS have already been demonstrated in the field of surface functionalization. Examples include structural colours (e.g. for optical effects or safety features), beneficial friction and wear reduction, modification of the wetting behaviour of surfaces, and antibacterial or cell adhesion promoting properties for medical implants. Despite decades of research, however, some aspects regarding the formation mechanism are still unclear and the subject of controversial debate. This involves the two main models of coherent electromagnetic scattering and matter reorganization, which are used for explaining aspects of LIPSS formation and phenomenology. One major issue is to quantify the actual amount of material removal during the fs-laser processing due to the lack of an independent depth reference and to visualize the so-called heat-affected zone accompanying intense fs-laser irradiation. In the present study, near-surface implantation of Mn and N ions into different material depth of Mn-free austenitic stainless steel alloy FeCrNiMo18-12-2 was used to create reference layers of a defined thickness containing the respective elements. LIPSS (type low-spatial frequency LIPSS, LSFL) were fabricated on the polished substrate surfaces in an air environment by fs-laser irradiation (λ = 1025 nm, τ = 300 fs, frep = 100 kHz, F = 1.5 J/cm2). The implanted layers subsequently served as a kind of coordinate system to assess the material removal during the formation process via cross-sectional Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDXS). Using both analysis methods enabled in particular to determine the position of peaks and valleys of the LIPSS topography in relation to the initial surface before fs-laser irradiation. This confirmed the selective ablation in the LIPSS valleys. Moreover, linking changes in the material’s microstructure, e.g., the crystallinity and near surface elemental composition before and after fs-laser treatment, gave additional insights regarding the transient cooling rates, as recently shown for NiTi alloys. T2 - 13th International LIPSS Workshop CY - Enschede, Netherlands DA - 29.10.2015 KW - Energy dispersive X-ray analysis (EDX) KW - Ion implantation KW - Laser-induced periodic surface structures (LIPSS) KW - Steel KW - Transmission electron microscopy (TEM) PY - 2025 AN - OPUS4-64900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Bacterial adhesion on ultrashort pulse laser processed surfaces ― more than size matters! N2 - Bacterial biofilms are aggregates of bacterial cells, often attached to a surface, and enclosed by a self-produced extracellular matrix which confers increased stress tolerance and resistance to cleaning. Biofilm formation leads to biofouling which gives rise to high costs in numerous technical settings due to biocorrosion and biodegradation. However, biofilms can also be attractive for industrial settings such as wastewater treatment systems or for soil bioremediation processes. Hence, the control of bacterial adhesion to a surface is of major concern. Surface topography strongly influences bacterial adhesion. Therefore, one promising way to achieve bacteria-guiding surfaces lies in the contactless and aseptic large-area laser processing of technical surfaces. We used short and ultrashort pulsed laser systems to generate different surface textures, mainly high-spatial-frequency and low-spatial-frequency laser-induced periodic surface structures, LIPSS (HFSL and LFSL), on Ti, Ti-alloy, steel, and polymers (PET and PE). Pristine (polished) and laser processed samples were subjected to bacterial adhesion experiments with two different Escherichia coli strains and Staphylococcus aureus as test organisms. The bacterial strains differed in their cell wall structure (grampositive vs. gramnegative strains), in size, shape, the occurrence of cell appendages, and in their biofilm forming capabilities. Adhesion patterns were analyzed microscopically and compared regarding the respective test strain and surface topography. Our results revealed that adhesion behavior strongly depends not only on the material’s topography and chemistry, but also on the specific bacterial strain, the presence of cell appendages, and ambient growth conditions. T2 - 13th International LIPSS Workshop CY - Enschede, Netherlands DA - 29.10.2025 KW - Bacterial adhesion KW - Biofilm KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses PY - 2025 AN - OPUS4-64632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voss, Heike T1 - Morphology and regularity of high-spatial frequency laser-induced periodic surface structures (HSFL) on titanium materials N2 - Titanium and its alloys are known to enable the straightforward laser‐based manufacturing of ordered surface nanostructures, so‐called high-spatial frequency laser‐induced periodic surface structures (HSFL). These structures exhibit sub‐100 nm spatial periods – far below the optical diffraction limit. The resulting surface functionalities are usually enabled by both, topographic and chemical alterations of the nanostructured surfaces. For exploring these effects, HSFL were processed on different titanium materials (bulk, film) upon irradiation with near‐infrared ps‐laser pulses (1030 nm wavelength, ≈1 ps pulse duration) under different laser scan processing conditions in normal air atmosphere. Here, we extend our previous work on chemical analyses of HSFL on titanium materials towards a more detailed large-area morphological and topographical surface characterization. For this purpose, scanning electron or atomic force microscopic images are subjected to a regularity analysis using our ReguΛarity software. The results are assessed with respect to the influences of sample- or laser-related parameters on the regularity of the HSFL. T2 - 13th International Conference on Photoexcited Processes and Applications, ICPEPA-13 CY - Lecce, Italy DA - 14.09.2025 KW - Laser-induced periodic surface structures (LIPSS) KW - Laser processing KW - Ulltrashort laser pulses KW - Titanium PY - 2025 AN - OPUS4-64173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gräf, S. T1 - Ion marker implantation for tracing the formation of femtosecond LIPSS on steel N2 - An ion marker experiment is conducted to investigate the formation of low spatial frequency laser-induced periodic surface structures (LIPSS) on stainless steel surfaces upon scan-processing with femtosecond laser pulses (300 fs, 1025 nm, 100 kHz) focussed to a spot diameter of ~20 µm. Defined concentration depth profiles of 14N^+- and 55Mn^+-ions were implanted below the polished surface of a cast Mn- and Si-free stainless steel AISI 316L using an acceleration energy of 380 keV. This generated two distinct “depth-tracer-layers” ~135 nm (55Mn) and ~340 nm (14N) below the sample surface. The sample morphology and microstructure were evaluated before and after LIPSS-processing using scanning and transmission electron microscopy techniques in top-view and cross-sectional geometry. Energy-dispersive X-ray spectroscopy (EDXS) allowed to visualize the depth distribution of the marker elements, the steel constituents, and of oxygen involved through the laser processing in ambient air. These experiments revealed that the LIPSS on this metal are predominantly formed by material removal through locally varying ablation and, to a lesser extent, by local melt displacement effects prior to the re-solidification. Moreover, the processing in air leads to the formation of a less than 10 nm thick laser-induced oxide layer covering the steel surface. Our new tracer ion approach contributes to the ongoing debate on the relevance of electromagnetic or hydrodynamic effects during the formation of LIPSS. T2 - E-MRS Spring Meeting 2025 CY - Strasbourg, France DA - 26.05.2026 KW - Laser-induced periodic surface structures (LIPSS) KW - Steel KW - Ion implantation KW - Transmission electron microscopy (TEM) KW - Energy dispersive X-ray analysis (EDX) PY - 2025 AN - OPUS4-63274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Obenlüneschloß, Jorit A1 - Boysen, Nils A1 - Rönnby, Karl A1 - Muriqi, Arbresha A1 - Hoffmann, Volker A1 - Abad Andrade, Carlos Enrique A1 - Rogalla, Detlef A1 - Brokmann, Ulrike A1 - Rädlein, Edda A1 - Nolan, Michael A1 - Devi, Anjana T1 - Ein seltener mononuklearer Lithium‐Carben‐Komplex für die Atomlagenabscheidung von lithiumhaltigen Dünnschichten N2 - KurzfassungLithium ist das zentrale Element moderner Batterietechnologien, und die Herstellung von lithiumhaltigen Materialien mittels Atomlagenabscheidung (engl. Atomic Layer Deposition, ALD) bietet erhebliche Vorteile bei der Kontrolle der Schichtdicke und ‐zusammensetzung. In dieser Studie wird ein neuer mononuklearer, durch ein N‐heterocyclisches Carben (NHC) stabilisierter Lithiumkomplex, [Li(tBuNHC)(hmds)], als vielversprechender Präkursor für die ALD von lithiumhaltigen Dünnschichten vorgestellt. Die strukturelle Charakterisierung erfolgt durch den Vergleich von Dichtefunktionaltheorie (DFT) und Einkristall‐Röntgenbeugung (engl. Single‐Crystal X‐ray Diffraction, SC‐XRD), wobei die seltene mononukleare Struktur bestätigt wird. Thermogravimetrische Analysen (TGA) zeigen vorteilhafte thermische Eigenschaften für ALD‐Anwendungen. Die Verbindung weist einen niedrigen Schmelzpunkt, saubere Verdampfung und ermutigende Volatilitätsparameter im Vergleich zu anderen Lithium‐Präkursoren auf. ALD‐Experimente mit [Li(tBuNHC)(hmds)] und Ozon zeigen dessen Effektivität bei der Abscheidung von LiSixOy‐Filmen. Der ALD‐Prozess zeigt ein gesättigtes Wachstum pro Zyklus (engl. Growth per Cycle, GPC) von 0,95 Å. Die Zusammensetzung, analysiert mittels Rutherford‐Rückstreu‐Spektrometrie/Kernreaktionsanalyse (engl. Rutherford Backscattering Spectrometry/Nuclear Reaction Analysis, RBS/NRA), Röntgenphotoelektronenspektroskopie (engl. X‐ray Photoelectron Spectroscopy, XPS) und Glimmentladungsspektroskopie (engl. Glow Discharge Optical Emission Spectrometry, GD‐OES), bestätigt das Vorhandensein von Lithium und Silizium in den erwarteten Verhältnissen. Diese Arbeit stellt nicht nur einen neuen ALD‐Präkursor vor, sondern trägt auch zum Verständnis der Lithiumchemie bei und bietet Einblicke in die faszinierende Koordinationschemie und das thermische Verhalten von durch NHC‐Liganden stabilisierten Lithiumkomplexen. KW - Atomlagenabscheidung KW - N-heterozyklischer-Carben-(NHC)-stabilisierter Lithium-Präkursor KW - Mononuklearer Li–Carben-Komplex KW - Lithiumsilicat-Dünnfilme KW - Filmanalytik/-Charakterisierung PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-644045 DO - https://doi.org/10.1002/ange.202513066 SN - 0044-8249 N1 - Es gibt eine parallele Sprachausgabe (englisch), ein Link befindet sich im Feld zugehöriger Identifikator - There is a parallel language edition (English), a link is in the field related identifier SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-64404 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Obenlüneschloß, Jorit A1 - Boysen, Nils A1 - Rönnby, Karl A1 - Muriqi, Arbresha A1 - Hoffmann, Volker A1 - Abad Andrade, Carlos Enrique A1 - Rogalla, Detlef A1 - Brokmann, Ulrike A1 - Rädlein, Edda A1 - Nolan, Michael A1 - Devi, Anjana T1 - Rare Mononuclear Lithium-Carbene Complex for Atomic Layer Deposition of Lithium Containing Thin Films N2 - Lithium is the core material of modern battery technologies and fabricating the lithium‐containing materials with atomic layer deposition (ALD) confers significant benefits in control of film composition and thickness. In this work, a new mononuclear N‐heterocyclic carbene (NHC) stabilized lithium complex, [Li(tBuNHC)(hmds)], is introduced as a promising precursor for ALD of lithium‐containing thin films. Structural characterization is performed, comparing density functional theory (DFT) and single‐crystal X‐ray diffraction (SC‐XRD), confirming a rare mononuclear structure. Favorable thermal properties for ALD applications are evidenced by thermogravimetric analysis (TGA). The compound exhibits a low melting point, clean evaporation, and its volatility parameters are encouraging compared to other lithium precursors. ALD trials using [Li(tBuNHC)(hmds)] with ozone demonstrate its effectiveness in depositing LiSixOy films. The ALD process exhibits a saturated growth per cycle (GPC) of 0.95 Å. Compositional analysis using Rutherford backscattering spectrometry/nuclear reaction analysis (RBS/NRA), X‐ray photoelectron spectrometry (XPS), and glow discharge optical emission spectrometry (GD‐OES), confirms the presence of lithium and silicon in the expected ratios. This work not only presents a new ALD precursor but also contributes to the understanding of lithium chemistry, offering insights into the intriguing coordination chemistry and thermal behavior of lithium complexes stabilized by NHC ligands. KW - Atomic layer deposition (ALD) KW - N-heterocyclic carbene (NHC) ligands KW - Lithium ALD precursor chemistry KW - Mononuclear Li–carbene complex [Li(tBuNHC)(hmds)] KW - Li-silicate thin films (LiSixOy) KW - Thermal properties & TGA/volatility KW - Compositional analysis (RBS/NRA, XPS, GD-OES) PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643790 DO - https://doi.org/10.1002/anie.202513066 SN - 1433-7851 N1 - Es gibt eine parallele Sprachausgabe (deutsch), ein Link befindet sich im Feld zugehöriger Identifikator - There is a parallel language edition (German), a link is in the field related identifier SP - 1 EP - 11 PB - Wiley-VCH CY - Weinheim AN - OPUS4-64379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Campos de Oliveira, Paula T1 - Advancing microstructural characterisation of ceramic cores for aerospace: from state-of-the-art to in-situ synchrotron X-ray computed tomography N2 - Ceramic cores are crucial for manufacturing turbine blades in aircraft engines, creating intricate cooling channels that improve engine efficiency and reduce emissions. During high-temperature casting, the cores undergo significant microstructural changes, including phase transitions, particle rearrangements, and porosity transformations, which can affect their properties and must be carefully controlled. State-of-the-art characterisation techniques for ceramic cores mostly rely on 2D methods, such as scanning and transmission electron microscopy. While valuable, these methods are limited in capturing the 3D complexity of the material. Advances in X-ray computed tomography (XCT) offer a more comprehensive perspective on 3D microstructures, but conventional XCT often lacks the resolution and in-situ capabilities to study microstructural evolution under casting conditions. Synchrotron XCT (SXCT) addresses these limitations, offering high spatial and temporal resolution with features down to 1 µm, enabling in-situ investigations. This study highlights the potential of SXCT, revealing previously unseen 3D microstructural features in ceramic cores, such as agglomeration, porosity evolution, surface reactions, microcracking, and particle orientation. These findings provide a more realistic view of dynamic changes during casting, advancing the understanding of core behaviour. Despite its advantages, SXCT is still rarely used in the field due to challenges such as limited access to synchrotron facilities and sample movement artifacts. Future developments, including high-temperature and vacuum compatible CT setups, could enhance this technique, leading to a better optimisation of ceramics performance. T2 - XIXth Conference of the European Ceramic Society (ECERS 2025) CY - Dresden, Germany DA - 31.08.2025 KW - Synchrotron KW - X-ray Computed Tomography KW - Ceramic core KW - Aerospace KW - Microstructure PY - 2025 AN - OPUS4-64050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul T1 - Morphological Analysis of Graphene Oxide by SEM and Correlative Field-Flow Fractionation Coupled with Multi-Angle Light Scattering N2 - Since the first free-standing monolayer graphene sheet was successfully prepared in 2004 [1], graphene and graphene oxide materials achieved the necessary technical readiness level to be considered for use in commercial products. Moreover, the focus has shifted from fundamental research towards expanding the applicability of graphene-related 2D materials (GR2M) and to improve their competitiveness with established materials [2]. Significant advances have been made especially in applications regarding optoelectronics, energy storage materials, chemical additives, sensor applications etc. [3]. Composite products containing graphene and functionalized graphene such as inks and dyes have shown enhanced performance regarding longevity, wettability, and can be tailored for specific purposes through dedicated functionalization. For accurate physico-chemical characterization, GR2M products in their raw form or as part of composites present challenges in terms of sample preparation, choice of analytical method and evaluation of data. For instance, in the context of imaging, these challenges encompass: (a) the selection of images magnifications being representative for all the flakes ranging in size from hundreds of nanometers to micrometers; (b) the selection of representative flakes for adequate statistics, which may involve the separation of overlapping/agglomerating flakes by segmentation; and (c) the classification of diverse morphologies such as irregularly shaped/crumpled flakes, porous flakes and particulate features present in the sample. The complexity of the analytical task has needed the introduction of specific ontology for 2D materials to identify the proper descriptors characterizing confidently the morphological features of interest. Regarding light scattering techniques such as Dynamic Light Scattering (DLS) and Multi-Angle Light Scattering (MALS) commonly used for process control in industry as a first measure, an alternative approach would be necessary. This is in part due to the use of the standard sphere-model for 2D materials as appearing to be inappropriate, whilst a disc-shape model potentially yields more suitable results. Standardization efforts are underway to establish a baseline for accurate characterization of aimed measurands with sufficient statistics. To date, the measurement methods recommended by standardization bodies for the morphological-structural characterization of GR2M’s are AFM, Raman Spectroscopy and SEM and/or TEM. The acquisition of statistically relevant numbers of flakes for a thorough characterization using TEM and AFM is particularly time-consuming. The size distribution of graphene oxide- and graphene-containing inks was investigated by using a correlative approach coupling Centrifugal Field-Flow Fractionation (CF3) [4] with MALS. Up to now, promising results for Field-Flow Fractionation have been achieved only with respect to the separation into size classes of GO samples as well as of graphene oxide mixed with graphene by Asymmetrical Field-Flow Fractionation (AF4) [5], [6]. Besides the online characterization by MALS, the eluting size fractions obtained by CF3 were also collected and subsequently measured by SEM. Successful separation into size fractions allows us to apply ensemble techniques such as MALS to samples that were previously not measurable according to best-practices. In this study, the following material sub-classes have been observed with SEM: (i) nano-graphite mixed with graphene flakes, (ii) graphene oxide few- and multi-layer flakes with diverse and highly complex morphology, and (iii) graphene oxide of well-defined size and shape with >95% single- and bilayer content were investigated. Data on the class size ranges was obtained by MALS after separation with CF3 and consideration of a disc-shape model. Significant effort was invested into the sample preparation for CF3 measurements to achieve a recovery rate of >80%, well above the recommended 70% by ISO/TS 21362:2018 for validation purposes. The material fractions collected after the CF3 measurement were separately deposited on a silicon wafer and the size results of the SEM analysis were correlated with the corresponding mean sizes obtained with MALS. T2 - Microscopy and Microanalysis 2025 CY - Salt Lake City, UTAH, USA DA - 27.07.2025 KW - Advanced Material KW - CF3 KW - SEM KW - Morphology PY - 2025 AN - OPUS4-64084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Correlative chemical imaging to reveal the nature of different commercial graphene materials N2 - Different synthesis techniques were developed which led to other graphene-related materials such as graphene oxide (GO) or elemental-doped graphene. Further chemical functionalization can enhance but also alter or reduce specific properties of the graphene. To reveal the nature of these materials a proper physico‑chemical characterization with different analytical techniques is crucial. Single-layer GO flakes provided by Graphenea (Spain) were prepared for systematic image analysis. These flakes were disposed on an alignment-marked SiO2 substrate and correlatively imaged by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and Raman spectroscopy. The high lateral resolution and/ or extreme surface sensitivity of the mentioned techniques is necessary to explore monolayers. The ToF-SIMS images match well with the SEM and AFM images and provide information about the chemistry. With 2D Raman spectroscopy it is possible to differentiate between the number of stacked single-layer flakes. This is visualized in a 3D image. Well-defined GO flakes could be used as a reference material for imaging of graphene-like structures but also of other types of 2D materials. In addition to these monolayer GO flakes, commercial graphene-containing inks (Haydale) with a more complex morphology were also correlatively imaged. ToF-SIMS and SEM images were merged to identify the origin of different chemical fragments. The findings correlate closely with the expectation that the specific functionalizations (with fluorine and nitrogen as marker elements) are present only on the graphene flakes as presumed from the SEM images. Energy-dispersive X-ray spectroscopy (EDX) supports these results, yet with a much lower sensitivity compared to ToF-SIMS. T2 - Joint Regulatory Risk Assessors Summit – Advancing Safety & Sustainability Assessments of Advanced Materials CY - Paris, France DA - 19.06.2025 KW - ToF-SIMS KW - Imaging KW - Graphene-related 2D materials KW - SEM/EDX KW - Auger electron spectroscopy KW - Raman spectroscopy PY - 2025 UR - https://macrame-project.eu/macrame-meetings-workshops/jointrras/#Agenda AN - OPUS4-63656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -