TY - JOUR A1 - Chemello, Giovanni A1 - Knigge, Xenia A1 - Ciornii, Dmitri A1 - Reed, B.P. A1 - Pollard, A.J. A1 - Clifford, C.A. A1 - Howe, T. A1 - Vyas, N. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - Influence of the Morphology on the Functionalization of Graphene Nanoplatelets Analyzed by Comparative Photoelectron Spectroscopy with Soft and Hard X-Rays N2 - Since its isolation, graphene has received growing attention from academia and industry due to its unique properties. However, the “what is my material” barrier hinders further commercialization. X-ray photoelectron spectroscopy (XPS) is considered as a method of choice for the determination of the elemental and chemical composition. In this work the influence of the morphology of graphene particles on the XPS results is studied and investigated as a function of X-ray energy, using conventional XPS with Al K𝜶 radiation and hard X-ray photoemission spectroscopy (HAXPES) using Cr K𝜶 radiation. Thereby, the information depth is varied between 10 and 30 nm. For this purpose, two commercial powders containing graphene nanoplatelets with lateral dimensions of either ≈100 nm or in the micrometer range are compared. These larger ones exist as stack of graphene layers which is inspected with scanning electron microscopy. Both kinds of particles are then functionalized with either oxygen or fluorine. The size of the graphene particles is found to influence the degree of functionalization. Only the combination of XPS and HAXPES allows to detect the functionalization at the outermost surface of the particles or even of the stacks and to provide new insights into the functionalization process. KW - Functionalized graphene KW - Hard-energy X-ray photoelectron spectroscopy KW - X-ray photoelectron spectroscopy PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578860 DO - https://doi.org/10.1002/admi.202300116 SN - 2196-7350 SP - 1 EP - 8 PB - Wiley VCH AN - OPUS4-57886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terborg, R. A1 - Kim, K. J. A1 - Hodoroaba, Vasile-Dan T1 - Elemental composition and thickness determination of thin films by electron probe microanalysis N2 - Electron probe microanalysis (EPMA) applies to solid samples of homogenous (bulk) chemical composition and can usually not be applied to structures which are inhomogeneous in the micrometer range such as thin film systems down to a few nm. However, in combination with the established thin film software Stratagem, the thickness as well as the elemental composition of thin films on a substrate can be determined. This has been recently successfully demonstrated for Fe-Ni on Si and Si-Ge on Al2O3 thin film systems. For both systems five samples of different elemental composition and a reference were produced and characterised by inductively coupled plasma mass spectrometry (ICP-MS), Rutherford backscattering (RBS), and transmission electron microscopy (TEM) as reference values. Last year, a new and open-source thin film evaluation programme called BadgerFilm has been released. It can also be used to determine thin film composition and thickness from intensity ratios of the unknown sample and standards (k-ratios). In this contribution, we reevaluated the data acquired for the Fe-Ni and Si-Ge systems using the BadgerFilm software package and compared the obtained elemental compositions and thickness values with the results of the Stratagem software and the reference methods. The conclusion is that the BadgerFilm software shows good agreement with the elemental composition and thickness calculated by Stratagem (mostly <2% for both composition and thickness) and with the reference values for two representative thin film systems (<1%–2% for composition and <10%–20% for thickness). KW - Elemental composition KW - EPMA KW - Film thickness KW - Thin films PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576368 DO - https://doi.org/10.1002/sia.7183 SN - 0142-2421 VL - 55 SP - 496 EP - 500 PB - Wiley AN - OPUS4-57636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Bartczack, Dorota A1 - Taché, Olivier A1 - Hodoroaba, Vasile-Dan T1 - Report on the homogeneity assessment of bimodal gold materials (nPSize1 and nPSize2) and particle number concentration by frequency method N2 - The main objective was to assess homogeneity of two bimodal gold materials, namely nPsize1 and nPSize2, containing approximately 1:1 and 10:1 particle number-based ratio of ~30nm and ~60nm particles. Particle number-based concentration within the two size fractions was determined with spICP-MS using the particle frequency method of calibration. KW - Nanoparticles KW - Homogeneity KW - Particle number concentration KW - Gold KW - nPSize PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595451 DO - https://doi.org/10.5281/zenodo.10654245 SP - 1 EP - 5 PB - Zenodo CY - Geneva AN - OPUS4-59545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ankli, P. P. A1 - Abdelwahab, A. A. A1 - Logachov, A. A1 - Bugiel, R. A1 - Drobne, D. A1 - Novak, S. A1 - Kranjc, E. A1 - Saje, S. A1 - Pellegrino, F. A1 - Alladio, E. A1 - Sordello, F. A1 - Corrao, E. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg A1 - Mrkwitschka, Paul A1 - Madbouly, Loay Akmaal A1 - Akdemir, Yücel A1 - Gulumian, M. A1 - Wepener, V. A1 - Andraos, C. A1 - Boodhia, K. A1 - Jones, E. A1 - Doolin, A. A1 - Leuchtenberg, K. A1 - Valsami Jones, E. A1 - Rocca, C. A1 - Ibrahim, B. A1 - Singh, D. A1 - Chakraborty, S. A1 - Jurkschat, K. A1 - Johnston, C. A1 - Van Der Zande, M. A1 - Fernandez, D. A1 - Queipo, P. A1 - Clifford, C. A1 - Hardy, B. T1 - Knowledge Infrastructure supporting image-based characterisation of 2D graphene materials N2 - As part of the European Horizon ACCORDs project, advanced methods are being developed for the image-based characterisation of 2D nanomaterials. Given the complexity of this task, robust nd wellorganised data management is critical to ensuring high-quality outcomes. To support this, we have established a knowledge infrastructure that serves as the central repository for protocols, images and experimental data which are stored in a standardised, harmonised manner and in accordance with the FAIR principles – Findable, Accessible, Interoperable and Reusable and open science. This machine-readable framework enables the systematic and computationally automated correlation of image features with experimental descriptors, facilitating accurate material characterisation and transparent reporting which is all integrated in the ACCORDs KI. KW - Graphene-related 2D materials (GR2M) KW - 2D materials KW - Knowledge infrastructure KW - Characterisation PY - 2025 DO - https://doi.org/10.1016/j.toxlet.2025.07.660 SN - 0378-4274 VL - 411 SP - S281 EP - S282 PB - Elsevier B.V. AN - OPUS4-65061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Characterization of Porous, TiO2 Nanoparticle Films Using On-Axis TKD in SEM – a New Nano-Analysis Tool for a Large-Scale Application N2 - A combined methodical approach is tested with respect to the characterization of the inner structure of porous TiO2 layers as typically used in modern dye sensitized solar cells (DSSC). Their performance is directly linked to the surface area of the pore network. The micrometer thick layer employed was manufactured by screen-printing of a starting TiO2 powder constituted of shape-controlled, bipyramidal anatase nanoparticles on FTO/glass substrates. The analytical methods exploited in our study are Focused Ion Beam (FIB) slicing followed by 3D reconstruction as well as the new approach transmission Kikuchi diffraction (TKD) technology in the scanning electron microscope (SEM). Size and shape distribution of the TiO2 NPs within the layer can be extracted. SEM in transmission mode and atomic force microscopy (AFM) have been used to verify the dimensional data obtained by the new combined methodical approach. Its analytical benefits but also the challenges and limitations are highlighted. T2 - Microscopy & Microanalysis 2017 Meeting CY - St. Louis, MO, USA DA - 06.08.2017 KW - Porous layers KW - TiO2 KW - Nanoparticles KW - Size and shape distribution KW - TKD KW - SEM PY - 2017 AN - OPUS4-41660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Other than spherical/monodisperse Towards real world NPs as candidate reference materials for traceable size measurements N2 - By far most of the current nanoparticle (NP) research is dealing with (quasi-) spherical and/or monodisperse particles. However, many NPs used in industrial applications are rather aspherical and polydisperse. This inhomogeneity considerably hampers their characterization and, particularly, the accurate determination of the nanoparticle size. In order to overcome this problem and to promote the availability of standardized size measurement methods, it is crucial to develop and establish (candidate) reference materials with inhomogeneous size (distribution), aspherical shape as well as agglomerated or aggregated particles. Therefore, a new set of NPs including Au-, SiO2 , and TiO2-particles is investigated. The range of properties comprises polydisperse spherical, bimodal spherical, rod-like, acicular, bipyramidal, sheet-like as well as cubic NPs. With respect to a good traceability of the measurements, size and size distributions of the candidate reference materials are determined using microscopic methods like scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning electron microscopy in transmission mode (STEM-in-SEM), atomic force microscopy (AFM) as well as small angle X-ray scattering (SAXS) as an ensemble technique. The development of protocols for sample preparation is of particular importance to obtain a homogeneous dispersion of the NPs on a substrate. Further, approaches for signal modelling for all the methods above are being developed. The initiation of two VAMAS (www.vamas.org/twa34/index.html) inter-laboratory comparisons on bipyramidal titania and bimodal silica with different modal concentration ratios will be also highlighted. T2 - E-MRS Spring Meeting 2021 CY - Online meeting DA - 31.05.2021 KW - Nanoparticles KW - Particle size distribution KW - Imaging KW - Traceability KW - Reference material PY - 2021 AN - OPUS4-52764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - EMPIR nPSize - Improved Traceability Chain of Nanoparticle Size Measurement; What nPSize can offer to CEN/TC 352? N2 - The main outcomes of the EMPIR project nPSize are presented and the suitability of the new capabilities (e.g. reference materials, measurement procedures, inter-laboratory comparisons) as pertinent contributions to normative projects within CEN/TC 352 Nanotechnologies are discussed. E.g. the first technical report of nPSize on full algorithm sequences for nanoparticle detection and size measurement as developed on both a physical basis (SEM, TSEM, AFM and SAXS) and by machine learning is put at disposal. T2 - 29th Meeting of CEN/TC 352 Nanotechnologies CY - Online meeting DA - 25.03.2021 KW - Nanoparticles KW - Electron microscopy KW - CEN/TC 352 Nanotechnologies KW - Particle size distribution KW - Modelling KW - Machine learning PY - 2021 AN - OPUS4-52464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ciornii, Dmitri A1 - Hodoroaba, Vasile-Dan A1 - Wachtendorf, Volker A1 - Fengler, Petra A1 - Altmann, Korinna T1 - Interlaboratory Comparison Reveals State of the Art in Microplastic Detection and Quantification Methods N2 - In this study, we investigate the current accuracy of widely used microplastic (MP) detection methods through an interlaboratory comparison (ILC) involving ISO-approved techniques. The ILC was organized under the prestandardization platform of VAMAS (Versailles Project on Advanced Materials and Standards) and gathered a large number (84) of analytical laboratories across the globe. The aim of this ILC was (i) to test and to compare two thermo-analytical and three spectroscopical methods with respect to their suitability to identify and quantify microplastics in a water-soluble matrix and (ii) to test the suitability of the microplastic test materials to be used in ILCs. Two reference materials (RMs), polyethylene terephthalate (PET) and polyethylene (PE) as powders with rough size ranges between 10 and 200 μm, were used to press tablets for the ILC. The following parameters had to be assessed: polymer identity, mass fraction, particle number concentration, and particle size distribution. The reproducibility, SR, in thermo-analytical experiments ranged from 62%−117% (for PE) and 45.9%−62% (for PET). In spectroscopical experiments, the SR varied between 121% and 129% (for PE) and 64% and 70% (for PET). Tablet dissolution turned out to be a very challenging step and should be optimized. Based on the knowledge gained, development of guidance for improved tablet filtration is in progress. Further, in this study, we discuss the main sources of uncertainties that need to be considered and minimized for preparation of standardized protocols for future measurements with higher accuracy. KW - Microplastics KW - Interlaboratory comparison KW - PlasticsFatE KW - PET KW - PE KW - Reference materials KW - VAMAS KW - Thermo-analytical methods KW - Spectroscopical methods PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630462 DO - https://doi.org/10.1021/acs.analchem.4c05403 SN - 1520-6882 VL - 97 SP - 8719 EP - 8728 PB - ACS Publications AN - OPUS4-63046 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 - Pellegrino, Francesco A1 - Maurino, V. A1 - Hodoroaba, Vasile-Dan T1 - Morphological Characterization and Chemical Identification of TiO2 Nanoparticles Doped with Ultrafine Metal Particles for Enhanced Photocatalytical Activity N2 - The conversion of solar energy into electricity and solar fuels is of crucial importance for a green and sustainable future. Water splitting using semiconductor photo-catalysts is considered a sustainable method to produce clean hydrogen (H2) fuel. Nevertheless, H2 photo-production efficiency remains still low, although extensive research works to understand better the mechanisms of the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are being carried out. In this respect, TiO2 is a key photoactive material, usually employed with a co-catalyst deposited onto the surface to enhance charge carriers’ separation and catalyze surface charge transfer reactions. The deposition of a co-catalyst on the TiO2 nanoparticle surface represents one successful way to enhance the activity of the photocatalyst through a modification of its surface and redox properties. In this context, high-resolution scanning electron microscopy coupled with elemental analysis by energy-dispersive X-ray spectroscopy (EDS) is fundamental for studying and understanding the effect of the nanoparticle morphology on the functional properties of shape-controlled TiO2 crystals (bipyramides, platelets, and elongated particles). Different types of metal-semiconductor combinations, TiO2 shapes and dopant metals (Ag, Pt, etc) and metal concentrations will be discussed. KW - Nanoparticles KW - Photocatalysis KW - Electron microscopy KW - EDS KW - Metal-semiconductor PY - 2022 DO - https://doi.org/10.1017/S1431927622010078 VL - 28 IS - Suppl. 1 SP - 2658 EP - 2660 PB - Cambridge University Press AN - OPUS4-55436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Report ISO/TC202/WG4 X-Ray Spectroscopy, Liaisons with VAMAS and ISO/TC229 Nanotechnologies N2 - The presentation is structured in the following three parts: i) Report of the Working Group 4 X-Ray Spectroscopy including the publication of ISO 15632:2021 Microbeam analysis — Selected instrumental performance parameters for the specification and checking of energy-dispersive X-ray spectrometers for use in electron probe microanalysis, ii) Liaison activities between ISO/TC202 Microbeam Anaylsis and VAMAS/TWA34 Quantitative Microstructural Analysis, and iii) Liaison activities from ISO/TC202 Microbeam Analysis for ISO/TC229 Nanotechnologies. Most relevant projects are highlighted for information and further discussions. New initiatives and better promotion of strategic projects are addressed. T2 - Annual Meeting of ISO/TC 202 Microbeam Analysis CY - Online meeting DA - 25.10.2021 KW - Microbeam Analysis KW - VAMAS KW - ISO/TC 202 KW - ISO/TC 229 KW - electron microscopy KW - X-Ray Spectroscopy KW - EBSD KW - FIB PY - 2021 AN - OPUS4-53625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - EMPIR nPSize - Improved Traceability Chain of Nanoparticle Size Measurement; nPSize offer after 2 Ys N2 - The main outcomes of the EMPIR project nPSize are presented and the suitability of the new capabilities (e.g. reference materials, measurement procedures, VAMAS inter-laboratory comparisons) to be standardized and implemented in accredited analytical laboratories is discussed. T2 - EMPIR nPSize Training Course "Metrology for Measurement of Nanoparticle Size by Electron Microscopy and Atomic Force Microscopy" CY - Online meeting DA - 27.10.2020 KW - Nanoparticles KW - Size KW - Shape KW - Traceability KW - EMPIR KW - Reference materials KW - VAMAS PY - 2020 AN - OPUS4-51477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Morpho-Chemical Characterisation of Me-TiO2 Nanoparticles for Enhanced Photocatalytical Activity N2 - The conversion of solar energy into electricity and solar fuels is of crucial importance for a green and sustainable future. Water splitting using semiconductor photo-catalysts is considered a sustainable method to produce clean hydrogen (H2) fuel. Nevertheless, H2 photo-production efficiency remains still low, although extensive research works to understand better the mechanisms of the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are being carried out. In this respect, TiO2 is a key photoactive material, usually employed with a co-catalyst deposited onto the surface to enhance charge carriers’ separation and catalyze surface charge transfer reactions. The deposition of a co-catalyst on the TiO2 nanoparticle surface represents one successful way to enhance the activity of the photocatalyst through a modification of its surface and redox properties. In this context, high-resolution scanning electron microscopy coupled with elemental analysis by energy-dispersive X-ray spectroscopy (EDS) is fundamental for studying and understanding the effect of the nanoparticle morphology on the functional properties of shape-controlled TiO2 crystals (bipyramides, platelets, and elongated particles). Different types of metal-semiconductor combinations, TiO2 shapes and dopant metals (Ag, Pt, etc) and metal concentrations will be discussed. T2 - ECASIA 2022 CY - Limerick, Ireland DA - 29.05.2022 KW - Titania nanoparticles KW - Photocatalysis KW - Scanning electron microscopy KW - Energy dispersive X-ray spectroscopy PY - 2022 AN - OPUS4-54977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Challenges in Traceable Size Measurement of Non-Spherical, Non-Monodisperse Nanoparticles - nPSize N2 - Size measurement of nanoparticles (NP) becomes a challenging analytical problem when non-spherical shapes must be traceably measured. However, most industrial NPs have irregular shapes and broad size distribution making it often more complex to follow European regulatory to identify a material as a nanomaterial according to which accurate measurement of the smallest dimension and its size Distribution is necessary. The European research project nPSize - Improved traceability chain of nanoparticle size measurements aims to fill this gap by developing potential non-spherical reference nanoparticles, measurement procedures and physical modelling to improve the traceability chain, comparability and compatibility for NP size measurements between different methods. Therefore, new model NP with well-controlled shape has been synthesized and are supposed to be systematically characterized using the traceable methods scanning/transmission electron microscopy, atomic force microscopy and small angle X-ray scattering. Following NP candidates are under investigation with respect to their homogeneity and stability: (i) titania nanoplatelets (10-15 nm thickness x 50-100 nm lateral), (ii) titania bipyramides (~60 nm length x 40 nm width), (iii) titania acicular particles (100 nm length x 15-20 nm width; aspect ratio 5.5/6), (iv) gold nanorods (~10 nm width x 30 nm length), and (v) gold nanocubes (~55 nm x 55 nm x 55 nm). In addition, sample preparation procedures as well as measurement analysis procedures with evaluation of appropriate measurands and descriptors for each material class and method are being developed to support standardization. To underpin the traceability of the size measurement of nonspherical NP, physical modelling of the signals in e.g. electron microscopy techniques will be used and in combination, the implementation of machine learning is aimed to facilitate measurement Analysis procedures, especially regarding the accurate thresholding/segmentation of the NPs.zeige mehr T2 - Nanoparticle Reference Materials - Production and Cerification Training Course CY - London, UK DA - 10.12.2019 KW - Nanoparticles KW - Traceability KW - Particle size distribution KW - Electron microscopy KW - Reference materials KW - Non-spherical shape PY - 2019 AN - OPUS4-50040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - New reference material candidates for traceable size measurement of nonspherical nanoparticles N2 - Size measurement of nanoparticles (NP) becomes a challenging analytical problem when non-spherical shapes must be traceably measured. However, most industrial NPs have irregular shapes and broad size distribution making it often more complex to follow European regulatory to identify a material as a nanomaterial according to which accurate measurement of the smallest dimension and its size Distribution is necessary. The European research project nPSize - Improved traceability chain of nanoparticle size measurements aims to fill this gap by developing potential non-spherical reference nanoparticles, measurement procedures and physical modelling to improve the traceability chain, comparability and compatibility for NP size measurements between different methods. Therefore, new model NP with well-controlled shape has been synthesized and are supposed to be systematically characterized using the traceable methods scanning/transmission electron microscopy, atomic force microscopy and small angle X-ray scattering. Following NP candidates are under investigation with respect to their homogeneity and stability: (i) titania nanoplatelets (10-15 nm thickness x 50-100 nm lateral), (ii) titania bipyramides (~60 nm length x 40 nm width), (iii) titania acicular particles (100 nm length x 15-20 nm width; aspect ratio 5.5/6), (iv) gold nanorods (~10 nm width x 30 nm length), and (v) gold nanocubes (~55 nm x 55 nm x 55 nm). In addition, sample preparation procedures as well as measurement analysis procedures with evaluation of appropriate measurands and descriptors for each material class and method are being developed to support standardization. To underpin the traceability of the size measurement of nonspherical NP, physical modelling of the signals in e.g. electron microscopy techniques will be used and in combination, the implementation of machine learning is aimed to facilitate measurement Analysis procedures, especially regarding the accurate thresholding/segmentation of the NPs. T2 - European Conference on Applications of Surface and Interface Analysis ECASIA 2019 CY - Dresden, Germany DA - 15.09.2019 KW - Nanoparticles KW - Size distribution KW - Electron microscopy KW - Certified reference materials KW - Traceability PY - 2019 AN - OPUS4-49227 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 - Hodoroaba, Vasile-Dan T1 - Advanced Characterization of the Surface Morphology and Chemistry within nano@BAM N2 - Both essential aspects of the surface of solid matter, its morphology and chemistry, are studied traditionally at BAM starting in the 60’s with different cyclical research focus areas, mostly related either to applicative research or method development. In the recent years, the focus has shifted almost exclusively to the nano-analytics of advanced materials such as complex nanoparticles, (ultra)thin films/coatings, nanocomposites, 2D materials, energy materials, etc. This is also the reason why BAM has established recently the new Competence Center nano@BAM (www.bam.de/Navigation/DE/Themen/Material/Nanotechnologie/sichere-nanomaterialien.html) with the five sub-fields nanoCharacterisation, nanoMaterial, nanoSafety, nanoData and nanoTechnology. The link to the BAM central guidelines to the safety in technology and chemistry is given by the development of reference products such as reference measurement procedures, reference (nano)materials, and newly reference data sets. Thus, an internationally well-networked group in surface analysis has been established @BAM, with regular contributions to integral analytical characterization with metrological and standardization background. Examples of newly developed methodical approaches will be given with an emphasis on correlative nano-analysis of morphology and chemistry of nanomaterials. Correlative imaging by STEM-in-SEM with high-resolution SEM and EDX, and further with AFM or the new technique TKD (Transmission Kikuchi Diffraction) will be explained on various examples of nanostructures, both as starting materials and embedded/functionalized nanoparticles in products. The unique analytical benefits of the Auger electron probe as a veritable nano-tool for surface chemistry will be highlighted. The panoply of advanced surface characterization methods @BAM is completed by discussing examples of hybrid analysis of the bulk of nanomaterials by X-ray Spectroscopy with the highest surface-sensitive methods X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). Particularly for the analysis of the surface chemistry of nanostructures, such as the completeness of the shells of core-shell nanoparticles or in-depth and lateral gradients of chemistry within mesoporous thin layers, the latter methods are inherent. Other special developments like approaches for the quantitative determination of the roughness of particle surface by electron microscopy or for the quantitative determination of the porosity of thin mesoporous layers by electron probe microanalysis (EPMA) with SEM will be presented in conjunction with the corresponding advanced materials studied. Current research projects, promising ideas, including ongoing (pre-)standardization activities in the field of the challenging nano/surface analysis will be touched systematically, with the open goal of identifying future bilateral cooperation possibilities between EMPA and BAM. T2 - EMPA-Kolloquium CY - Online meeting DA - 01.12.2021 KW - Nanoparticles KW - Nano@BAM KW - Nanomaterials KW - Surface morphology and chemistry KW - Correlative analysis PY - 2021 AN - OPUS4-54039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Ongoing VAMAS interlaboratory comparisons on nanoparticles size and shape as pre standardisation projects for harmonized measurements N2 - Traceable morphological and chemical characterization of nanomaterials with respect to the various possible sizes, size distributions, shapes, and concentrations of real-world nanoparticles (NPs) is a challenging task. Particularly for the nonspherical, non-monodisperse nanoparticles – as typically for most of the commercial particles, including their strong tendency to agglomerate, there is a lack of standard operation procedures providing accurate nanoparticle characterisation. In the framework of the pre-standardisation framework of VAMAS (Versailles Project on Advanced Materials and Standards, www.vamas.org) two interlaboratory comparison (ILC) studies are being carried out under the Technical Working Area (TWA) 34 “Nanoparticle Populations”:i) Project #15 addresses the analysis of the size and shape distribution of TiO2 bipyramidal NPs by traceable imaging methods such as TEM, SEM, STEM-in-SEM, AFM as well as with SAXS as an ensemble method. This ILC is thought as the next level development of the case studies exemplified in the published ISO standards ISO 21363 and ISO 19749. It was agreed to complete the first ILC with the NPs already prepared according to the same procedure on a TEM grid, and, at a later stage, to carry out second ILCs with the same NPs distributed to the participants as liquid suspensions together with protocols for the uniform NP deposition on suited substrates - as developed and optimized within the European project nPSize. Once having good deposition protocols available, the door for automated image analysis gets opened. Corresponding image analysis protocols and reporting templates have been distributed to the ILC participants, too. ii) Project #16: two spherical SiO2 NP samples with bi-modal size distributions in two nominal relative number concentrations were prepared and distributed also as liquid suspensions accompanied by sample preparation, measurement, and image analysis protocols and reporting templates. Here, the NP concentration is the primary parameter to be measured. For the imaging methods it is targeted to measure the relative nanoparticle concentrations (relative populations of the two modes). The results of all the participating laboratories, in both ILCs, compiled in comparative representations will be shown and discussed for the first time. The reduction of the measurement uncertainties associated to the size, shape and number-concentration results induced by the significant improvement of the sample preparation on substrates (as single particles with a high-density coverage), combined with welldefined image analysis procedures will be highlighted. T2 - 2024 Spring Meeting of the European Materials Research Society (E-MRS) CY - Strasbourg, France DA - 27.05.2024 KW - VAMAS KW - Interlaboratory comparison KW - Electron microscopy KW - Particle size distribution KW - Article concentration PY - 2024 AN - OPUS4-60184 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Marcoulaki, E. A1 - van Duuren, B T1 - Testing and benchmarking nanosafety services N2 - One of the objectives of the EU Project EC4SafeNano (European Centre for Risk Management and Safe Innovation in Nanomaterials & Nanotechnologies) was to test and benchmark the services in order to check their relevance to address identified stakeholder needs, but also to evaluate the governance of the structure delivering the proposed services. The aim is to demonstrate the technical relevance of the services and the overall open structure organisation, including governance rules and operating procedures, by answering relevant identified questions (case studies) selected by a panel of stakeholders. Therefore, a significant part of the project will be devoted to this demonstration of the operational and functional basis of the organized network. T2 - Review Meeting EC4SafeNano CY - Brussels, Belgium DA - 16.01.2020 KW - Nanosafety KW - EC4SafeNano KW - Nanosafety services KW - EU KW - Case studies PY - 2020 AN - OPUS4-50273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Standardized workflow for checking the performance of an EDS X-ray spectrometer at a Scanning Electron Microscope N2 - For test laboratories operating under accreditation schemes like ISO/IEC 17025 (ISO/IEC 17025), as the international reference for testing and calibration laboratories wanting to demonstrate their capacity to deliver reliable results, a periodical control of the critical instrumental parameters of an Energy-Dispersive X-ray Spectrometer (EDS) is required. This periodical check of an EDS is specified with exact procedures and materials in the ISO 15632:2021 ”Microbeam Analysis – Selected instrumental performance parameters for the specification and checking of energy-dispersive X-ray spectrometers for use in electron probe microanalysis” (ISO 15632). The EDS check can be simplified to the acquisition of only one 10 kV spectrum from a dedicated test material, EDS-TM002, which is made available by BAM since 2009 (https://webshop.bam.de/webshop_en/). The optional BAM software “EDX spectrometer check” is destined to automatically evaluate this spectrum and determine the performance of the EDS in terms of energy resolution and calibration, as well as possible alteration of low-energy efficiency due to detector contamination. Nearly 200 laboratories have the EDS-TM and associated software package in use. Practical examples based on various types of artifacts occurred in the EDS spectra and a long-term (>10 years) meticulous observation of the own spectrometers will be discussed. Different types of EDS spectrometers are considered, e.g. Si(Li) and SDD, of various window types (AP, the recent one Si3N4 or even windowless), and with different front contact layers (Au and Ni) (Hodoroaba and Procop, 2014). Evaluation of other parameters or effects such as the deadtime at different count rates or pileup effects is also explained with examples. T2 - Workshop "Automated Mineralogy" @ GEOANALYSIS 2022 CY - Freiberg, Germany DA - 06.08.2022 KW - EDS KW - X-ray spectrometer KW - Performance check KW - Test material KW - Standardized check KW - EDS-TM002 PY - 2022 UR - https://geoanalysis2021.de/en/workshops/automated-mineralogy AN - OPUS4-55460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -