TY - JOUR A1 - Božičević, Lucija A1 - Altmann, Korinna A1 - Hildebrandt, Jana A1 - Knigge, Xenia A1 - Vrček, Valerije A1 - Peranić, Nikolina A1 - Kalcec, Nikolina A1 - Vinkovic Vrcek, Ivana T1 - Estrogenic activity of plastic nanoparticles mixture under in vitro settings N2 - The plastic value chain, central part of modern living, caused environmental pollution and bioaccumulation of plastic nanoparticles (PNPs). Their ubiquitous presence in different environmental and biological compartments has become a serious threat to human health and ecosystems. Frequently used plastic materials such as polypropylene (PP), polystyrene (PS) and polyethylene (PE) have been detected in the form of PNPs in the food chain, soil, water and air, as well as in human feces and blood. In this study, we aimed to provide novel insights in endocrine disrupting properties of PNPs using in vitro estrogen receptor (ER) transactivation assay. The effects of PP-NPs, PE-NPs and PS-NPs and their mixture on T47D-KBluc cell line stably transfected with luciferase as reporter enzyme was evaluated by means of cytotoxicity, cellular uptake and ER activation. Tested dose range for PNPs was 0.001 – 10 mg/L. Both cellular uptake and cytotoxicity for all PNPs was found to be dose-dependent. Only the highest dose of PP-NPs and PE-NPs induced apoptosis and cell death, while PS-NPs were not cytotoxic in tested dose range. For tested concentrations, PP-NPs and PE-NPs showed significant agonistic activity on ER, while PS-NPs cannot be considered ER active. When, applied as mixture, PNP demonstrated additive toxicity effects compared to the effect of each individual PNPs. Additivity was also observed for ER agonistic effect of PNPs mixture according to the benchmark dose-addition modelling approach. This study provides missing science-based evidence on endocrine disrupting effects of PE-NPs, PP-NPs, PS-NPs and their mixtures and highlights the importance of considering unintentional, aggregate and combined exposure to different PNPs in risk management. KW - Risk assessment KW - Nanoplastics KW - Estrogenic activity of plastic nanoparticles PY - 2024 DO - https://doi.org/10.1039/D3EN00883E SN - 2051-8153 VL - 11 IS - 5 SP - 2112 EP - 2126 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Breitenbach, Romy A1 - Gerrits, Ruben A1 - Dementyeva, Polina A1 - Knabe, Nicole A1 - Schumacher, Julia A1 - Feldmann, Ines A1 - Radnik, Jörg A1 - Ryo, M. A1 - Gorbushina, Anna T1 - The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering N2 - The roles extracellular polymeric substances (EPS) play in mineral attachment and weathering were studied using genetically modified biofilms of the rock-inhabiting fungus Knufia petricola strain A95. Mutants deficient in melanin and/or carotenoid synthesis were grown as air-exposed biofilms. Extracted EPS were quantified and characterised using a combination of analytical techniques. The absence of melanin affected the quantity and composition of the produced EPS: mutants no longer able to form melanin synthesised more EPS containing fewer pullulan-related glycosidic linkages. Moreover, the melanin-producing strains attached more strongly to the mineral olivine and dissolved it at a higher rate. We hypothesise that the pullulan-related linkages, with their known adhesion functionality, enable fungal attachment and weathering. The released phenolic intermediates of melanin synthesis in the Δsdh1 mutant might play a role similar to Fe-chelating siderophores, driving olivine dissolution even further. These data demonstrate the need for careful compositional and quantitative analyses of biofilm-created microenvironments. KW - Biofilms PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549025 DO - https://doi.org/10.1038/s41529-022-00253-1 SN - 2397-2106 VL - 6 SP - 1 EP - 11 PB - Springer Nature CY - London AN - OPUS4-54902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Breitenbach, Romy A1 - Gerrits, Ruben A1 - Dementyeva, Polina A1 - Knabe, Nicole A1 - Schumacher, Julia A1 - Feldmann, Ines A1 - Radnik, Jörg A1 - Ryo, M. A1 - Gorbushina, Anna T1 - Data for "The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering" N2 - Data for the publication "The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering" (https://doi.org/10.1038/s41529-022-00253-1). It includes: - The Summary of the EPS concentration, EPS sugar components and EPS linkages. - The Summary of the XPS analysis of freeze-dried biofilm samples of all strains. - The Summary of the pH, Mg, SI and Fe concentration, biomass and olivine dissolution rate for each time point of all dissolution experiments. KW - Biofilms PY - 2022 DO - https://doi.org/10.26272/opus4-54901 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-54901 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 - JOUR A1 - Bresch, Harald A1 - Hodoroaba, Vasile-Dan A1 - Schmidt, Alexandra A1 - Rasmussen, K. A1 - Rauscher, H. T1 - Counting Small Particles in Electron Microscopy Images — Proposal for Rules and Their Application in Practice N2 - Electron microscopy (EM) is the gold standard for the characterisation of the morphology (size and shape) of nanoparticles. Visual observation of objects under examination is always a necessary first step in the characterisation process. Several questions arise when undertaking to identify and count particles to measure their size and shape distribution. In addition to challenges with the dispersion and identification of the particles, more than one protocol for counting particles is in use. This paper focuses on precise rules for the counting of particles in EM micrographs, as this influences the measurement accuracy of the number of particles, thus implicitly affecting the size values of the counted particles. We review and compare four different, commonly used methods for counting, which we then apply in case studies. The impact of the selected counting rule on the obtained final particle size distribution is highlighted. One main aim of this analysis is to support the application of a specific, well-defined counting approach in accordance with regulatory requirements to contribute to achieving more reliable and reproducible results. It is also useful for the new harmonised measurement procedures for determining the particle size and particle size distribution of nanomaterials. KW - Nano KW - Particle size distribution KW - Nanoparticle KW - Nanomaterial KW - OECD PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551891 DO - https://doi.org/10.3390/nano12132238 SN - 2079-4991 VL - 12 IS - 13 SP - 2238 PB - MDPI CY - Basel AN - OPUS4-55189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brinkmann, A. T1 - A qNMR Method for Quantification of Surface Functional Groups on Silica Nanoparticles: Bilateral Comparisons N2 - Nanomaterials (NM) of different size, shape, morphology, composition, and surface chemistry are used in a wide range of applications, including medical diagnostics, and imaging and consumer products. The importance of an adequate and reliable characterization is crucial for quality control during NM production, for ensuring an optimum function for the desired application, and for risk assessment studies. Currently there is a lack of reliable and validated methods and reference materials for quantifying NM surface functional groups, despite the importance of surface chemistry for the production of colloidally stable materials, further processing steps, and the interaction with the environment and biological species. Following our initial study on the use of qNMR for quantifying the amount of amino groups on surface modified silica (1), we have carried out two bilateral comparisons between NRC and BAM to further develop and optimize a reliable protocol for these measurements (2,3), using aminated silica nanoparticles prepared by multiple methods, both commercial and in-house synthesized, and with varying amine content. Solution qNMR is based on dissolving aminated silica nanoparticles in strong base to release the surface grafted amino silane molecules, followed by the quantification of these molecules by solution qNMR using an internal standard. This method provides the amount of total amino groups present in the sample, which can differ from probe accessible or surface-sensitive measurements performed with X-Ray photoelectron spectroscopy (XPS). Complementary measurements using optical assays, involving a labeling step with a dye reporter, and XPS are employed to assess the probe accessible and surface amine content for representative samples. These measurements, which illustrate the advantages and potential limitations of the different characterization methods, will contribute to establish a basis for testing the protocol in an international inter-laboratory comparison and for standardization at ISO Technical Committee 229 – Nanotechnologies. T2 - BERM CY - Halifax, Canada DA - 01.06.2025 KW - Quality assurance KW - Nano KW - Particle KW - Synthesis KW - Advanced materials KW - Characterization KW - Electron microscopy KW - Silica KW - Surface KW - qNMR KW - Optical assay KW - Interlaboratory comparison KW - Metrology KW - Standardization PY - 2025 AN - OPUS4-63527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Broicher, Cornelia A1 - Zeng, F. A1 - Pfänder, N. A1 - Frisch, M. A1 - Bisswanger, T. A1 - Radnik, Jörg A1 - Stockmann, Jörg M. A1 - Palkovits, S. A1 - Beine, A. K. A1 - Palkovits, R. T1 - Iron and Manganese Containing Multi-Walled Carbon Nanotubes as Electrocatalysts for the Oxygen Evolution Reaction - Unravelling Influences on Activity and Stability N2 - Hydrogen economy is a central aspect of future energy supply, as hydrogen can be used as energy storage and fuel. In order tomake water electrolysis efficient, the limiting oxygen evolution reaction (OER) needs to be optimized. Therefore, C-based composite materials containing earth-abundant Fe and Mn were synthesized, characterized and tested in the OER. For pyrolysis temperatures above 700°C N-rich multi-walled carbon nanotubes (MWCNT) are obtained. Inside the tubes Fe3C particles are formed, Fe and Mn oxides are incorporated in the carbon matrix and metal spinel nanoparticles cover the outer surface. The best catalyst prepared at 800°C achieves a low overpotential of 389 mV (at 10 mA/cm2) and high stability (22.6 h). From electrochemical measurements and characterization it can be concluded that the high activity is mainly provided by MWCNT, Fe3C and the metal oxides in the conductive carbon matrix. The metal spinel nanoparticles in contrast protect the MWCNT from oxidation and thereby contribute to the high stability. KW - Oxygen Evolution Reaction KW - Carbon Nanotubes KW - Stability PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513955 DO - https://doi.org/10.1002/cctc.202000944 VL - 12 IS - 21 SP - 1 EP - 8 PB - Wiley Online Libary AN - OPUS4-51395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Broichert, C. A1 - Klingenhof, M. A1 - Frisch, M. A1 - Dresp, S. A1 - Kubo, N.M. A1 - Artz, J. A1 - Radnik, Jörg A1 - Palkovits, S. A1 - Beine, A.K. A1 - Strasser, P. A1 - Palkovits, R. T1 - Particle size-controlled synthesis of highperformance MnCo-based materials for alkaline OER at fluctuating potentials N2 - For the large-scale generation of hydrogen via water electrolysis the design of long term stable and active catalysts for the oxygen evolution reaction (OER) remains a key challenge. Most catalysts suffer from severe structural corrosion that becomes even more pronounced at fluctuating potentials. Herein, MnCo based cubic particles were prepared via a hydrothermal approach, in which the edge length of the micron-sized particles can be controlled by changing the pH value of the precursor solution. The cubes are composed of varying amounts of MnCo2O4, CoCO3 and a mixed (Mn/Co)CO3 phase. Structure–activity relationships were deduced revealing a volcano-type behavior for the intrinsic OER activity and fraction of spinel oxide phase. A low overpotential of 0.37 V at 10 mA cm−2 and a stability of more than 25 h was achieved in 1.0 M KOH using a rotating disc electrode (RDE) setup. The best performing catalyst material was successfully tested under dynamic process conditions for 9.5 h and shows a superior catalytic activity as anode for the Overall water splitting in an electrolyser setup in 1.0 M KOH at 333 K compared to a reference NiCo-spinel catalyst. KW - Water electrolysis KW - Oxygen evolution reaction KW - Structure activity relationships PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-536050 DO - https://doi.org/10.1039/d1cy00905b SN - 2044-4753 VL - 11 IS - 12 SP - 7278 EP - 7286 PB - Royal Society of Chemistry AN - OPUS4-53605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brüngel, R. A1 - Rückert, J. A1 - Müller, P. A1 - Babick, F. A1 - Friedrich, C. M. A1 - Ghanem, A. A1 - Hodoroaba, Vasile-Dan A1 - Mech, A. A1 - Weigel, S. A1 - Wohlleben, W. A1 - Rauscher, H. T1 - NanoDefiner Framework and e-Tool Revisited According to the European Commission’s Nanomaterial Definition 2022/C 229/01 N2 - The new recommended definition of a nanomaterial, 2022/C 229/01, adopted by the European Commission in 2022, will have a considerable impact on European Union legislation addressing chemicals, and therefore tools to implement this new definition are urgently needed. The updated NanoDefiner framework and its e-tool implementation presented here are such instruments, which help stakeholders to find out in a straightforward way whether a material is a nanomaterial or not. They are two major outcomes of the NanoDefine project, which is explicitly referred to in the new definition. This work revisits the framework and e-tool, and elaborates necessary adjustments to make these outcomes applicable for the updated recommendation. A broad set of case studies on representative materials confirms the validity of these adjustments. To further foster the sustainability and applicability of the framework and e-tool, measures for the FAIRification of expert knowledge within the e-tool’s knowledge base are elaborated as well. The updated framework and e-tool are now ready to be used in line with the updated recommendation. The presented approach may serve as an example for reviewing existing guidance and tools developed for the previous definition 2011/696/EU, particularly those adopting NanoDefine project outcomes. KW - Nanomaterial definition KW - Nanomaterial categorisation KW - Nanomaterial regulation KW - Nanomaterial legislation KW - Decision support KW - FAIRification PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571618 DO - https://doi.org/10.3390/nano13060990 SN - 2079-4991 VL - 13 IS - 6 - Special Issue "Identification and Quantification of Nanomaterials" SP - 1 EP - 16 PB - MDPI CY - Basel, CH AN - OPUS4-57161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bui, Minh A1 - Heinekamp, Christian A1 - Fuhry, Emil A1 - Weidner, Steffen A1 - Radnik, Jörg A1 - Ahrens, Mike A1 - Scheurell, Kerstin A1 - Balasubramanian, Kannan A1 - Emmerling, Franziska A1 - Braun, Thomas T1 - Lewis-acid induced mechanochemical degradation of polyvinylidene fluoride: transformation into valuable products N2 - Polyvinylidene fluoride (–[CH2CF2]n–, PVDF) waste poses significant environmental challenges due to its recalcitrant nature and widespread use. This study addresses the end-of-life management of PVDF by introducing a novel, sustainable mechanochemical approach for its valorisation. We investigated the degradation of PVDF into value-added materials using ball milling with anhydrous AlCl3 to achieve a quantitative mineralisation producing AlF3 and halide-functionalised graphite, along with gaseous products (HCl and CH4). Mechanistic key steps involve Lewis-acid catalysed C–F bond activation, dehydrofluorination and aromatisation. This approach provides an effective solution for PVDF waste management while offering a promising route for the production of high-value materials from polymer waste streams. Our findings contribute to sustainable practices in polymer recycling and resource recovery, respond to pressing environmental concerns associated with fluoropolymer disposal, and demonstrate the potential to convert polymer wastes into useful products. KW - Mechanochemistry KW - Polyvinylidenfluoride KW - Degradation KW - Ball mill PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649015 DO - https://doi.org/10.1039/d5sc05783c SN - 2041-6520 VL - 16 IS - 40 SP - 18903 EP - 18910 PB - Royal Society of Chemistry (RSC) AN - OPUS4-64901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Böttcher, Katrin A1 - Kraft, Sebastian A1 - Weise, Matthias A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - X-ray emission during ultrafast laser grooving N2 - Ultrashort pulse lasers offer the possibility to process materials with minimal heat input and high precision. However, the X-ray emission at high laser peak intensities represents an undesirable side effect. A laser system (1030 nm wavelength, 40 W maximum average laser power, 925 fs pulse duration, 100 μJ maximum pulse energy, 400 kHz pulse repetition frequency) was used to analyze the X-ray skin dose rates for applied peak intensities between 9.2 × 10^12 W/cm^2 and 1.3 × 10^14 W/cm^2 for mild steel, stainless steel and tungsten during groove processing. The lowest laser peak intensity at which X-ray emission could be measured was 9.2 × 10^12 W/cm^2 for processing of stainless steel. The X-ray emission showed a characteristic evolution in dependence on the number of overscans at the same line positions. For low peak intensities, a measurable X-ray emission only begins after a few passes. The number of scans to reach the maximum dose rate increases with lower laser peak intensity. Analysis of the evolving surface topography by white light interference microscopy in connection with ray-tracing simulations led to the interpretation that the increase in X-ray emission is due to the local intensity redistribution by multiple reflection within the laser-generated grooves which is promoted by a particular choice of the linear laser polarization. KW - Ultrashort pulsed laser KW - Laser-induced X-rays KW - X-ray hazard KW - X-ray emission PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639483 DO - https://doi.org/10.1007/s00339-025-08728-z SN - 1432-0630 VL - 131 IS - 8 SP - 1 EP - 12 PB - Springer CY - Berlin AN - OPUS4-63948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cano Murillo, Natalia A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagl, Dorothee A1 - Emamverdi, Farnaz A1 - Cacua, K. A1 - Hodoroaba, Vasile-Dan A1 - Sturm, Heinz T1 - Carrier Fibers for the Safe Dosage of Nanoparticles in Nanocomposites: Nanomechanical and Thermomechanical Study on Polycarbonate/Boehmite Electrospun Fibers Embedded in Epoxy Resin N2 - The reinforcing effect of boehmite nanoparticles (BNP) in epoxy resins for fiber composite lightweight construction is related to the formation of a soft but bound interphase between filler and polymer. The interphase is able to dissipate crack propagation energy and consequently increases the fracture toughness of the epoxy resin. Usually, the nanoparticles are dispersed in the resin and then mixed with the hardener to form an applicable mixture to impregnate the fibers. If one wishes to locally increase the fracture toughness at particularly stressed positions of the fiber-reinforced polymer composites (FRPC), this could be done by spraying nanoparticles from a suspension. However, this would entail high costs for removing the nanoparticles from the ambient air. We propose that a fiber fleece containing bound nanoparticles be inserted at exposed locations. For the present proof-of-concept study, an electrospun polycarbonate nonwoven and taurine modified BNP are proposed. After fabrication of suitable PC/EP/BNP composites, the thermomechanical properties were tested by dynamic mechanical analysis (DMA). Comparatively, the local nanomechanical properties such as stiffness and elastic modulus were determined by atomic force microscopy (AFM). An additional investigation of the distribution of the nanoparticles in the epoxy matrix, which is a prerequisite for an effective nanocomposite, is carried out by scanning electron microscopy in transmission mode (TSEM). From the results it can be concluded that the concept of carrier fibers for nanoparticles is viable. KW - Advanced materials KW - Electrospun nanocomposite fiber KW - Nanomechanical charecteisation KW - Nanosafety KW - Epoxy nanocomposites PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528265 DO - https://doi.org/10.3390/nano11061591 VL - 11 IS - 6 SP - 1591 PB - MDPI CY - CH - 4020 Basel, Switzerland AN - OPUS4-52826 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Cano Murillo, Natalia A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagl, Dorothee A1 - Hahn, Marc Benjamin A1 - Hodoroaba, Vasile-Dan A1 - Sturm, Heinz T1 - Cover image for the article "Nanomechanical study of polycarbonate/boehmite nanoparticles/epoxy ternary composite and their interphases" N2 - The image designed by Natalia Cano Murillo and colleagues shows the cross section of a ternary composite (boehmite/polycarbonate/epoxy, 80μm x 80μm). The surface was measured by AFM kelvin probe microscopy, yielding the surface potential which is shown as 3D‐surface and contour lines. The sample was further subjected to AFM force spectroscopy with a lateral resolution of 1μm², yielding the local Young's modulus, projected in false colors on the 3D surface. The ternary system, containing boehmite nanoparticles, shows a broad distribution of modulus, desirable for optimized macroscopic mechanical properties, such as high stiffness as well as toughness. KW - Boehmite KW - Epoxy KW - Polycarbonate KW - AFM KW - BNP PY - 2020 DO - https://doi.org/10.1002/app.50400 SN - 0021-8995 SN - 1097-4628 VL - 138 IS - 12 SP - 1 PB - Wiley CY - New York, NY AN - OPUS4-51831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cano Murillo, Natalia A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagl, Dorothee A1 - Hahn, Marc Benjamin A1 - Hodoroaba, Vasile-Dan A1 - Sturm, Heinz T1 - Nanomechanical study of polycarbonate/boehmite nanoparticles/epoxy ternary composite and their interphases N2 - Thermoplastic modified thermosets are of great interest especially due to their improved fracture toughness. Comparable enhancements have been achieved by adding different nanofillers including inorganic particles such as nanosized boehmite. Here, we present a nanomechanical study of two composite systems, the first comprising a polycarbonate (PC) layer in contact with epoxy resin (EP) and the second consisting of a PC layer containing boehmite nanoparticles (BNP) which is also in contact with an EP layer. The interaction between PC and EP monomer is tested by in situ Fourier transformed infrared (FT-IR) analysis, from which a reaction induced phase separation of the PC phase is inferred. Both systems are explored by atomic force microscopy (AFM) force spectroscopy. AFM force-distance curves (FDC) show no alteration of the mechanical properties of EP at the interface to PC. However, when a PC phase loaded with BNP is put in contact with an epoxy system during curing, a considerable mechanical improvement exceeding the rule of mixture was detected. The trend of BNP to agglomerate preferentially around EP dominated regions and the stiffening effect of BNP on EP shown by spatial resolved measurements of Young's modulus, suggest the effective presence of BNP within the EP phase. KW - Composites KW - Mechanical properties KW - Nanoparticles KW - Thermoplastics KW - Thermosets PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515965 DO - https://doi.org/10.1002/app.50231 SN - 0021-8995 SN - 1097-4628 VL - 138 IS - 12 SP - 1 EP - 11 PB - Wiley CY - New York, NY AN - OPUS4-51596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cant, D. J. H. A1 - Minelli, C. A1 - Sparnacci, K. A1 - Müller, Anja A1 - Kalbe, H. A1 - Stoger-Pollach, M. A1 - Unger, Wolfgang A1 - Werner, W. S. M. A1 - Shard, A. G. T1 - Surface-Energy Control and Characterization of Nanoparticle Coatings N2 - Accurate and reproducible measurement of the structure and properties of high-value nanoparticles is extremely important for their commercialization. A significant proportion of engineered nanoparticle systems consist of some form of nominally core-shell structure, whether by design or unintentionally. Often, these do not form an ideal core-shell structure, with typical deviations including polydispersity of the core or shell, uneven or incomplete shells, noncentral cores, and others. Such systems may be created with or without intent, and in either case an understanding of the conditions for formation of such particles is desirable. Precise determination of the structure, composition, size, and shell thickness of such particles can prove challenging without the use of a suitable range of characterization techniques. Here, the authors present two such polymer core-shell nanoparticle systems, consisting of polytetrafluoroethylene cores coated with a range of thicknesses of either polymethylmethacrylate or polystyrene. By consideration of surface energy, it is shown that these particles are expected to possess distinctly differing coating structures, with the polystyrene coating being incomplete. A comprehensive characterization of these systems is demonstrated, using a selection of complementary techniques including scanning electron microscopy, scanning transmission electron microscopy, thermogravimetric analysis, dynamic light scattering, differential centrifugal sedimentation, and X-ray photoelectron spectroscopy. By combining the results provided by these techniques, it is possible to achieve superior characterization and understanding of the particle structure than could be obtained by considering results separately. KW - Nanoparticles KW - Core-shell KW - XPS KW - Size KW - Thickness KW - Damage PY - 2020 DO - https://doi.org/10.1021/acs.jpcc.0c02161 VL - 124 IS - 20 SP - 11200 EP - 11211 PB - ACS CY - Washington DC AN - OPUS4-50899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cant, D. J. H. A1 - Müller, Anja A1 - Clifford, C. A. A1 - Unger, Wolfgang A1 - Shard, A. G. T1 - Summary of ISO/TC 201 Technical Report 23173—Surface chemical analysis—Electron spectroscopies—Measurement of the thickness and composition of nanoparticle coatings N2 - ISO Technical Report 23173 describes methods by which electron spectroscopies, including X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and synchrotron techniques, can be employed to calculate the Coating thicknesses and compositions of nanoparticles. The document has been developed to review and outline the current state-of-the-art for such measurements. Such analyses of core–shell nanoparticles are common within the literature, however the methods employed are varied; the relative advantages and disadvantages of These methods, and the optimal usage of each may not be clear to the general analyst. ISO Technical Report 23173 aims to clarify the methods that are available, describe them in clear terms, exhibit examples of their use, and highlight potential issues users may face. The information provided should allow analysts of electron spectroscopy data to make clear choices regarding the appropriate analysis of electron spectroscopy data from coated nanoparticle systems and provide a basis for understanding and comparing results from different methods and systems. KW - Electron spectroscopy KW - Core-shell KW - Nanoparticles KW - ISO 23173 KW - XPS KW - Thickness KW - Composition PY - 2021 DO - https://doi.org/10.1002/sia.6987 SN - 0142-2421 VL - 53 IS - 10 SP - 893 EP - 899 PB - John Wiley & Sons Ltd AN - OPUS4-52976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chemello, Giovanni T1 - Characterization of industrial graphene using HAXPES N2 - A comparative analysis is performed by XPS, HAXPES and SEM of industrial functionalised graphene powder of different morphology. The chemical analysis carried out by XPS, which probing depth is around 10nm, and HAXPES, which can reach up to 30nm probing depth. By combining these two techniques is possible to get a rough, non-destructive depth profiling of the sample's surface. The results show a higher concentration of the functionlisation elements on the surface of the sample and the influence of the morphology on the functionalisation process and the C/O ratio. T2 - SALSA Make and Measure 2022 CY - Berlin, Germany DA - 15.09.2022 KW - Graphene KW - XPS KW - HAXPES KW - SEM KW - Graphene funcionalisation PY - 2022 AN - OPUS4-55971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chemello, Giovanni T1 - Analysis of industrial graphene-based flakes – first results on morphological characterization, sample preparation and chemical composition N2 - Before industrial grade graphene could reach comparable quality to the controlled laboratory scale material, many challenges must be overcome. In order to bridge the gap between lab-scale and industrial-scale production is necessary to develop processes, equipment and measurement procedures to control the material features. One of the most crucial reasons of graphene’s limited commercialization is the lack of standard procedures to properly characterize and define the material chemical and structural properties down to the nanometer level. This leads to many issues regarding material synthesis repeatability, inappropriateness choice of measurands and measurement reproducibility which heavily affect the consistency of the material performance. For example, among all the different industrially produced real-world graphene, it is crucial to determine how many layers of graphene build the material. Products that are built by more than 10 layers should be more correctly referred as nanosized graphite, a problem that is often regarded as the “fake graphene” issue. In our study, a comparative analysis is performed on two different series (G5 and G6) of industrial graphene powders, each series produced with four types of functionalization: raw graphene, oxygen-functionalized, nitrogen-functionalized and fluorine-functionalized. All the 8 sample variants were analyzed from a chemical and morphological point of view in the form of powders prepared as slightly pressed in metallic sample holders. The results of the comparative chemical analyses XPS and EDS show a good agreement in the concentration values for all the elements present in the samples, despite the different analysis volumes addressed by the two techniques. For this reason, the samples can be considered homogeneous in both lateral and vertical direction. A clear influence of the morphology on the composition is evident. Therefore, such correlative measurements of morphology and composition are necessary for a comprehensive characterization of industrial graphene flakes. Protocols for reliable characterization of industrial graphene flakes are in progress. T2 - Microscopy and Microanalysis 2022 CY - Portland, OR, USA DA - 31.07.2022 KW - Graphene powder KW - Functionalized graphene KW - XPS KW - SEM KW - EDS PY - 2022 AN - OPUS4-55479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chemello, Giovanni T1 - Measurement of the morphology of graphene related 2D materials as flakes N2 - The presentation shows the results of the mini-interlaboratory comparison focused on the measurement of the morphology of graphene oxide flakes using scanning electron microscopy. In this work, a route for the sample preparation, SEM measurement and image analysis is proposed. The results of the image analysis, performed on 200+ flakes per sample, are presented by comparing the distributions of the size and shape descriptors calculated according to two different approaches. The influences of a different SEM measurement operator, analysis approach and analysis operator on the final size and shape distributions are highlighted. T2 - EMRS Fall 2023 CY - Warsaw, Poland DA - 18.09.2023 KW - Graphene oxide KW - SEM KW - 2D flakes KW - Image analysis PY - 2023 AN - OPUS4-58752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chemello, Giovanni T1 - Characterization of Graphene using HAXPES N2 - Since its discovery, graphene has got growing attention in the industrial and application research due to its unique properties . However, graphene has not been yet implemented into the industrial market, in particularly due to the difficulty of properly characterizing this challenging material. As most of other nanomaterials, graphene’s properties are closely linked to its chemical and structural properties, such as number of layers, flake thickness, degree of functionalisation and C/O ratio. For the commercialization, suitable procedures for the measurement and characterization of the ultrathin flakes, of lateral dimensions in the range from µm to tens of µm, are essential.Surface chemical methods, especially XPS, have an outstanding role of providing chemical information on the composition. Thereby, one well-known problem for surface analytical methods is the influence of contamination on the composition as in the case of adventitious carbon. The differentiation between carbon originated from the contamination or from the graphene sample itself is often not obvious, which can lead to altered results in the determination of the composition. To overcome this problem, Hard Energy X-ray Photoelectron Spectroscopy (HAXPES) offers new possibilities due to its higher information depth. Therefore, XPS measurement obtained with Al Kα radiation (E = 1486. 6 eV) were compared with analyses performed with a Cr Kα (E = 5414. 8 eV) excitation on functionalized graphene samples. Differences are discussed in terms of potential carbon contamination, but also of oxygen on the composition of the samples. Measurements are performed on O-, N- and F-functionalized graphene. Different preparation procedures (powder, pellet, drop cast from liquid suspension) will be also discussed, correlation of the results with the flakes morphology as well as their validation with other independent methods are in progress. T2 - ECASIA 2022 CY - Limerick, Ireland DA - 29.05.2022 KW - Graphene KW - Functionalized graphene KW - Depth profiling PY - 2022 AN - OPUS4-56814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -