TY - JOUR A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - 1,3-Dimethyl-imidazolium dimethyl phosphate ([MMIM]+[DMP]−) analyzed by XPS and HAXPES N2 - The ionic liquid 1,3-dimethyl-imidazolium-dimethylphosphate ([MMIM]+[DMP]−) was analyzed using (hard) x-ray photoelectron spectroscopy. Here, XPS and HAXPES spectra are shown in comparison. For the acquisition of the XPS spectra, monochromatic Al Kα radiation at 1486.6 eV was used, while for the acquisition of the HAXPES spectra, monochromatic Cr Kα radiation at 5414.8 eV was applied. Here, survey scans and high-resolution spectra of P 2p, P 2s, C 1s, O 1s, and N 1s for both methods and P 1s, P KL2,3L2,3, and P KL1L2,3 for HAXPES are shown. KW - C7H15N2O4P KW - [MMIM]+[DMP]− KW - Lonic liquid KW - Hard x-ray photoelectron spectroscopy KW - HAXPES KW - XPS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571604 DO - https://doi.org/10.1116/6.0002297 VL - 30 IS - 1 SP - 1 EP - 20 PB - AIP Publishing AN - OPUS4-57160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Radnik, Jörg A1 - Ermilova, Elena A1 - Hodoroaba, Vasile-Dan T1 - Accuracy on all scales: Hybrid metrology for micro- and nanomanufacturing N2 - In this presentation, we discuss hybrid metrology and correlative imaging. These techniques are used to improve the design and quality monitoring of nanomaterials used in energy technology and for referencing the properties of nanoparticles. T2 - EMN for Advanced Manufacturing workshop CY - Berlin, Germany DA - 22.05.2024 KW - Nanotechnology KW - Nanoanalytics KW - Correlative Spectroscopy KW - Correlative Imaging PY - 2024 AN - OPUS4-60240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Chemello, Giovanni A1 - Radnik, Jörg T1 - Morphology Analysis of Graphene Oxide Flakes with SEM - Preparation of an Inter-Laboratory Comparison @VAMAS N2 - Experience gained at BAM within the European project ISGScope on the accurate measureemnt of graphene oxide flakes by electron microscopy is presented. Particularly, factors such as the type of solvent, substrate temperature, but also proper, gentle measurement parameters and image analysis conditions towards automation are highlighted. The measurement procedures in develeopment are being prepared to launch an inter-laboratory comparison under VAMAS (TWA41) as preparatory guidance for future standardisation at ISO. T2 - ISO/TC 229 Nanotechnologies Plenary Meeting - Graphene Standardisation CY - Teddington, UK DA - 14.11.2022 KW - Graphene oxide flakes KW - SEM KW - Morphology KW - VAMAS KW - Standardisation KW - Sample preparation KW - ISOGScope PY - 2022 AN - OPUS4-56300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stockmann, Jörg M. A1 - Radnik, Jörg A1 - Bütefisch, S. A1 - Busch, I. A1 - Weimann, T. A1 - Passiu, C. A1 - Rossi, A. A1 - Unger, Wolfgang T1 - New Test Specimen for the Determination of the Field of View of Small-Area XPS N2 - Small-area/spot photoelectron spectroscopy (SAXPS) is a powerful tool for the investigation of small surface features like microstructures of electronic devices, sensors or other functional surfaces. For evaluating the quality of such microstructures, it is crucial to know whether a small signal in a spectrum is an unwanted contamination of the field of view (FoV), defined by the instrument settings, or it originated from outside. The aperture has a major influence on the signal-contribution from the outside. For the evaluation of the FoV, we determined the Au4f intensities measured with the center of the FoV aligned with the center of the spot and normalized to the Au4f intensity determined on the Au-film. With this test specimen, it was possible to characterize the FoV: The signal-contribution from the outside is reduceable down to lower than 50 %, when the aperture is 30 % of the structure dimension for our Kratos AXIS Ultra DLD system. T2 - Kratos User's Meeting 2020 CY - Online meeting DA - 21.09.2020 KW - Small Area XPS KW - Reference Material KW - Imaging XPS KW - Field of View PY - 2020 AN - OPUS4-51413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chemello, Giovanni A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan 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 - JOUR A1 - Rautenberg, Max A1 - Gernhard, M. A1 - Radnik, Jörg A1 - Witt, Julia A1 - Roth, C. A1 - Emmerling, Franziska T1 - Mechanochemical synthesis of fluorine-containing Co-doped zeolitic imidazolate frameworks for producing electrocatalysts N2 - Catalysts derived from pyrolysis of metal organic frameworks (MOFs) are promising candidates to replace expensive and scarce platinum-based electrocatalysts commonly used in polymer electrolyte membrane fuel cells. MOFs contain ordered connections between metal centers and organic ligands. They can be pyrolyzed into metal- and nitrogen-doped carbons, which show electrocatalytic activity toward the oxygen reduction reaction (ORR). Furthermore, metal-free heteroatom-doped carbons, such as N-F-Cs, are known for being active as well. Thus, a carbon material with Co-N-F doping could possibly be even more promising as ORR electrocatalyst. Herein, we report the mechanochemical synthesis of two polymorphs of a zeolitic imidazole framework, Co-doped zinc 2-trifluoromethyl-1H-imidazolate (Zn0.9Co0.1(CF3-Im)2). Time-resolved in situ X-ray diffraction studies of the mechanochemical formation revealed a direct conversion of starting materials to the products. Both polymorphs of Zn0.9Co0.1(CF3-Im)2 were pyrolyzed, yielding Co-N-F containing carbons, which are active toward electrochemical ORR. KW - Mechanochemistry KW - Metal-organic-frameworks KW - Nobel-metal free electrocatalysis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546833 DO - https://doi.org/10.3389/fchem.2022.840758 SN - 2296-2646 VL - 10 IS - 840758 SP - 1 EP - 13 PB - Frontiers Media CY - Lausanne AN - OPUS4-54683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heilmann, Maria A1 - Prinz, Carsten A1 - Bienert, Ralf A1 - Wendt, R. A1 - Kunkel, B. A1 - Radnik, Jörg A1 - Hoell, A. A1 - Wohlrab, S. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska T1 - Size-Tunable Ni–Cu Core–Shell Nanoparticles—Structure, Composition, and Catalytic Activity for the Reverse Water–Gas Shift Reaction N2 - A facile and efficient methodology is described for the solvothermal synthesis of size-tunable, stable, and uniform NiCu core–shell nanoparticles (NPs) for application in catalysis. The diameter of the NPs is tuned in a range from 6 nm to 30 nm and to adjust the Ni:Cu ratio from 30:1 to 1:1. Furthermore, the influence of different reaction parameters on the final NPs is studied. The NPs are structurally characterized by a method combination of transmission electron microscopy, anomalous small-angle X-ray scattering, X-ray absorption fine structure, and X-ray photoelectron spectroscopy. Using these analytical methods, it is possible to elucidate a core–shell–shell structure of all particles and their chemical composition. In all cases, a depletion from the core to the shell is observed, with the core consisting of NiCu alloy, surrounded by an inner Ni-rich shell and an outer NiO shell. The SiO2-supported NiCu core–shell NPs show pronounced selectivity of >99% for CO in the catalytic reduction of CO2 to CO using hydrogen as reactant (reverse water–gas shift reaction) independent of size and Ni:Cu ratio. KW - Nanoparticles KW - Core-shell KW - Catalysis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543606 DO - https://doi.org/10.1002/adem.202101308 SN - 1438-1656 SP - 1 EP - 13 PB - Wiley VCH AN - OPUS4-54360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schutter, Jan David A1 - Eberhardt, Karl A1 - Elert, Anna Maria A1 - Radnik, Jörg A1 - Geißler, Daniel A1 - Özcan Sandikcioglu, Özlem T1 - Synthesis and characterization of lipopolysaccharide (LPS) anchored polystyrene microparticles as a synthetic model system for attachment studies N2 - Outer membrane lipopolysaccharides (LPS) play a crucial role in determining attachment behavior and pathogenicity of bacteria. The aim of this study was to develop a simple procedure for anchoring bacterial lipopolysaccharides to polystyrene (PS) microparticles as a model system for in situ attachment studies. By using a swellcapture methodology, commercially available LPS of Pseudomonas aeruginosa (strain ATCC 27316 serotype 10.22) was anchored onto PS microparticles in a proof-of-concept study. A detailed chemical and morphological characterization has proven the success of LPS incorporation. It was shown that the coverage and structure of the LPS film was concentration dependent. The procedure can easily be adapted to LPS of other bacterial strains to generate a synthetic model toolkit for attachment studies. KW - Bacterial lipopolysaccharides KW - Pseudomonas aeruginosa KW - Polystyrene microparticles KW - Swell-capture KW - Biomimicry PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579818 DO - https://doi.org/10.1016/j.colsurfb.2023.113301 SN - 0927-7765 VL - 226 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-57981 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 - CONF A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Terborg, R. A1 - Kim, K.J. T1 - Elemental Composition and Thickness Determination of Thin Films by Electron Probe Microanalysis (EPMA) N2 - microscopy (AFM), or X-ray reflectometry. For the additional determination of thin film composition, techniques like X-ray photoelectron spectroscopy (XPS) or mass spectrometry-based techniques can be used. An alternative non-destructive technique is electron probe microanalysis (EPMA). This method assumes a sample of homogenous (bulk) chemical composition, so that it cannot be usually applied to thin film samples. However, in combination with the thin film software StrataGEM, the thickness as well as the composition of such films on a substrate can be determined. This has been demonstrated for FeNi on Si and SiGe on Al2O3 film systems. For both systems five samples with different elemental composition and a reference were produced and characterised by Korean research institute KRISS using inductively coupled plasma mass spectrometry (ICP-MS), Rutherford backscattering (RBS), and transmission electron microscopy (TEM). These samples were used for an international round robin test. In 2021, 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 re-evaluated the data acquired for the FeNi and SiGe systems using the BadgerFilm software package and compared the resulting composition and thickness with the results of the established StrataGEM software and other reference methods. With the current evaluation, the BadgerFilm software shows good agreement with the composition and thickness calculated by StrataGEM and as the reference values provided by the KRISS. T2 - ECASIA 2022 CY - Limerick, Ireland DA - 29.05.2022 KW - Thin films KW - Electron Probe Microanalysis KW - Interlaboratory Comparisons PY - 2022 AN - OPUS4-54963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Keller, Lisa-Marie A1 - Scholz, Lena A1 - Weigert, Florian A1 - Radnik, Jörg A1 - Rühle, Bastian A1 - Bresch, Harald T1 - Nanocarriers – Challenges Imposed by Material Characterization N2 - A brief perspective of BAM on nanocarriers is presented including examples with special emphasis on the characterization of such materials and underlying challenges. In this respect, also ongoing activities at BAM on different types of core/shell nanomaterials and related systems are briefly summarized. T2 - Kolloquium BfR CY - Online meeting DA - 18.03.2021 KW - Nanomaterial KW - Nanocarrier KW - Size KW - Surface chemistry KW - Release kinetics KW - Chemical composition KW - Core/shell nanoparticle KW - Quantum dot KW - Spectroscopy KW - Fluorescence PY - 2021 AN - OPUS4-52412 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Dietrich, Paul M. A1 - Radnik, Jörg T1 - Near-ambient-pressure XPS as as tool to monitor DNA radiation damage directly in water N2 - Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further. T2 - Miller Conference CY - Furiani, France DA - 03.06.2023 KW - Base damage KW - Base loss KW - Cancer treatment KW - DNA KW - DNA radiation damage KW - Direct damage KW - Dissociative electron attachment (DEA) KW - Dissociative electron transfer (DET) KW - Dosimetry KW - Double-strand break (DSB) KW - ESCA KW - Energy deposit KW - G5P KW - Geant4 KW - Geant4-DNA KW - Hydrated DNA KW - Hydrated electron KW - Hydroxyl radical KW - Indirect damage KW - Ionisation KW - Ionization KW - LEE KW - Low energy electrons KW - MCS KW - Microdosimetry KW - NAP-XPS KW - Near ambient pressure xray photo electron spectroscopy KW - Net-ionization reaction KW - OH radical KW - PES KW - Particle scattering KW - Prehydrated electron KW - Presolvated electron KW - Protein KW - Quasi-direct damage KW - ROS KW - Radiation damage KW - Radiation therapy KW - Radical KW - Radiolysis KW - Radiotherapy KW - Reactive oxygen species KW - Simulation KW - Single-strand break (SSB) KW - Single-stranded DNA-binding proteins KW - TOPAS KW - TOPAS-nbio KW - XPS KW - Xray KW - Xray photo electron spectrocopy KW - Hydration shell PY - 2023 AN - OPUS4-57646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Chemello, Giovanni A1 - Hodoroaba, Vasile-Dan T1 - VAMAS ILC of functionalized Graphene by XPS and Graphene Oxide by SEM N2 - The ideas of the planned VAMAS interlaboratory comparisons of functionalized graphene and graphene oxide are presented. T2 - Stakeholder Advisory Board ISO-G-Scope CY - Online meeting DA - 12.01.2022 KW - Graphene KW - XPS KW - SEM PY - 2022 AN - OPUS4-54375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of sterilized CeO2 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterilized CeO2 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - XPS KW - HAXPES KW - SEM KW - NanoSolveIT KW - CeO2 nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7941461 PB - Zenodo CY - Geneva AN - OPUS4-57667 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Topolniak, Ievgeniia A1 - Hodoroaba, Vasile-Dan A1 - Benemann, Sigrid A1 - Pfeifer, Dietmar A1 - Sturm, Heinz T1 - Novel Boehmite-embedded organic/inorganic hybrid nanocomposite: cure behaviour, morphology and thermal properties N2 - Hybrid materials have attracted growing interest during the last decade, particularly due to their extraordinary properties. Cycloalyphatic-epoxy oligosiloxane (CEO) resin was shown to be a good candidate as a barrier material for the encapsulation purposes. Incorporation of inorganic nanoparticles such as Boehmite (BA) into polymers was observed to modify their specific characteristics, in particular, thermal, thermo-oxidative and barrier ones. In this work, novel BA-embedded organic inorganic hybrid nanocomposite material was engineered by combining the advantageous properties of hybrid polymers and nanoparticle enhancement effect. Impacts of particles on the photocuring kinetics, degree of crosslinking and the resultant changes in the thermal properties of the cured films were investigated. CEO synthesis via condensation reaction was confirmed by 1H and 29Si NMR. The particle distribution within the films was verified by SEM including transmission mode coupled with EDX elemental analysis. Photocuring kinetics and thermal properties of the films were studied by in situ FTIR spectroscopy and DSC with TGA, respectively. T2 - Deutschen Physikalischen Gesellschaft CY - Berlin, Germany DA - 11.03.2018 KW - Boehmite KW - Nanocomposite KW - Cycloalyphatic epoxy oligosiloxane KW - CEO PY - 2018 AN - OPUS4-44520 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 - JOUR A1 - Müller, Anja A1 - Krahl, T. A1 - Radnik, Jörg A1 - Wagner, Andreas A1 - Werner, W. S. M. A1 - Ritter, B. A1 - Kemnitz, E. A1 - Unger, Wolfgang T1 - Chemical in-depth analysis of (Ca/Sr)F2 core–shell like nanoparticles by X-ray photoelectron spectroscopy with tunable excitation energy N2 - The fluorolytic sol–gel synthesis is applied with the intention to obtain two different types of core–shell nanoparticles, namely, SrF2–CaF2 and CaF2–SrF2. In two separate fluorination steps for core and shell formation, the corresponding metal lactates are reacted with anhydrous HF in ethylene glycol. Scanning transmission electron microscopy (STEM) and dynamic light scattering (DLS) confirm the formation of particles with mean dimensions between 6.4 and 11.5 nm. The overall chemical composition of the particles during the different reaction steps is monitored by quantitative Al Kα excitation X-ray photoelectron spectroscopy (XPS). Here, the formation of stoichiometric metal fluorides (MF2) is confirmed, both for the core and the final core–shell particles. Furthermore, an in-depth analysis by synchrotron radiation XPS (SR-XPS) with tunable excitation energy is performed to confirm the core–Shell character of the nanoparticles. Additionally, Ca2p/Sr3d XPS intensity ratio in-Depth profiles are simulated using the software Simulation of Electron Spectra for Surface Analysis (SESSA). In principle, core–shell like particle morphologies are formed but without a sharp interface between calcium and strontium containing phases. Surprisingly, the in-depth chemical distribution of the two types of nanoparticles is equal within the error of the experiment. Both comprise a SrF2-rich core domain and CaF2-rich shell domain with an intermixing zone between them. Consequently, the internal morphology of the final nanoparticles seems to be independent from the synthesis chronology. KW - Metal fluorides KW - Sol-gel synthesis KW - Synchrotron radiation KW - X-ray photoelectron spectroscopy PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522284 DO - https://doi.org/10.1002/sia.6937 SN - 0142-2421 VL - 53 IS - 5 SP - 494 EP - 508 PB - Wiley VCH AN - OPUS4-52228 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 - CONF A1 - Chemello, Giovanni A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan 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 - Topolniak, Ievgeniia A1 - Elert, Anna Maria A1 - Knigge, Xenia A1 - Cinar Ciftci, G. A1 - Radnik, Jörg A1 - Sturm, Heinz T1 - Direct laser surface micropatterning with polydopamine N2 - Inspired by the chemistry of mussel adhesive proteins, polydopamine (PDA) is one of the simplest and most versatile approaches to confer new functionalities to nearly any material surface. Moreover, PDA exhibits high potential for surface modification and diversified secondary reactions that makes it extremely interesting for a wide range of application including biomedical field, e.g., drug delivery, adhesives, cell adhesion, biosensing. PDA has undergone significant expansion in its applications and is one of the most attractive areas within the materials field. Nevertheless, PDA integration in microdevices is still constrained by poor spatial and temporal control of excited deposition methods. Herein, we demonstrate a novel maskless approach for PDA micropatterning based on Direct Laser Writing (DLW) that overcomes present limitations. The pattern is formed upon exposure of the dopamine solution by light produced by tightly-focused fs NIR laser that scans substrate surface accordingly to the selected pattern design. Neither strong oxidants, metal ions nor adjusting pH to alkaline is required by this technique. Our method achieves the PDA micropatterns with the spatial resolution of 0.8 µm, at least an order of magnitude smaller than what is possible with other PDA microplanning techniques. The here introduced PDA deposition technique will uniquely unravel applications of polydopamine and other catecholamine-based mussel-inspired materials in various multifunctional systems and microdevices (e.g., MEMS elements, microfluidics). Adjustment of MPL parameters revealed that the morphology and thickness of resulted PDA microstructures can be controlled by altering the laser power and its scanning velocity. As a result, it also enables the production of micropatterns with structural gradient. Apart from the glass substrate, we achieved PDA patterning at surfaces of different nature such as polychlorotrifluoroethylene, polydimethylsiloxane, polyethylene terephthalate, silicon wafers, and fluorinated glass coverslips. The chemical nature of PDA was confirmed by locally recorded vibrational and x-ray photoelectron spectra. To ensure post-modification potential of MPL deposited PDA we demonstrated one-step deposition of micropatterns with trypsin. Obtained bio-functionalised surface can be further applied as a protein sensing active microelement. Presented in this work DLW-based microfabrication technique and the possibilities for further PDA surface post-functionalization empowers advanced applications of this material in single-molecule bioassays, sensors and other complex microdevices. T2 - Swiss ePrint 2022 CY - Buchs, Switzerland DA - 05.09.2022 KW - Polydopamine KW - Two-photon polymerisation KW - Micropatterning PY - 2022 AN - OPUS4-56422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radnik, Jörg A1 - Kersting, R. A1 - Hagenhoff, B. A1 - Bennet, Francesca A1 - Ciornii, Dmitri A1 - Nymark, P. A1 - Grafström, R. A1 - Hodoroaba, Vasile-Dan T1 - Reliable Surface Analysis Data of Nanomaterials in Support of Risk Assessment Based on Minimum Information Requirements N2 - The minimum information requirements needed to guarantee high-quality surface Analysis data of nanomaterials are described with the aim to provide reliable and traceable Information about size, shape, elemental composition and surface chemistry for risk assessment approaches. The widespread surface analysis methods electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) were considered. The complete analysis sequence from sample preparation, over measurements, to data analysis and data format for reporting and archiving is outlined. All selected methods are used in surface analysis since many years so that many aspects of the analysis (including (meta)data formats) are already standardized. As a practical analysis use case, two coated TiO2 reference nanoparticulate samples, which are available on the Joint Research Centre (JRC) repository, were selected. The added value of the complementary analysis is highlighted based on the minimum information requirements, which are well-defined for the analysis methods selected. The present paper is supposed to serve primarily as a source of understanding of the high standardization level already available for the high-quality data in surface analysis of nanomaterials as reliable input for the nanosafety community. KW - Electron microscopy KW - X-ray photoelectron spectroscopy KW - Secondary ion mass spectrometry KW - Energy dispersive X-ray spectroscopy KW - Standardization PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522683 DO - https://doi.org/10.3390/nano11030639 VL - 11 IS - 3 SP - 639 PB - MDPI AN - OPUS4-52268 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Topolniak, Ievgeniia A1 - Hodoroaba, Vasile-Dan A1 - Pfeifer, Dieter A1 - Braun, Ulrike A1 - Sturm, Heinz T1 - Influence of Boehmite nanofiller on the properties of cycloaliphatic-epoxy oligosiloxane resin coatings N2 - Organic-inorganic nanostructured materials have drawn much attention over the past decade, particularly due to their versatile and outstanding properties. Possessing the properties between those of polymers and those of glasses, siloxane-based resins are non-toxic, easy to synthesize and process hybrid materials, that hold a promising potential in the field of advanced coatings. Photocurable resins are nowadays widely used as coatings due to their unique advantages. In particular, cationic ring-opening curing is not inhibited by oxygen, leads to low degree of shrinkage and superior adhesion. The most important, it enables production of high-quality coatings within short exposure times without applying temperature, thus, minimizing the presence of the thermal stress in the substrate. Photocured Cycloaliphatic-Epoxy Oligosiloxane (CEO) resin was reported to be used as encapsulation material for organic electronics. However, further reinforcement of CEO properties is desired to achieve requested device lifetime. One of the common approaches to improve material characteristics is by embedding inorganic nanoparticles into polymer matrix. It has been shown that the resulted nanocomposites exhibit enhanced functional properties included but not limited by optical, mechanical, thermal and barrier ones. In this work we focused on the incorporation of Boehmite nanoparticles (BA) into CEO matrix as a tool to strengthen the film properties and to study the main changes occurred in the material behavior with regard to its photocuring kinetics, thermal stability and glass transition. Particular interest was focused on the role of particle surface in nanocomposite properties. Hence, BA particles without (HP14) and with organic surface modifier (OS1) at different loadings (up to 10 wt%) were applied in this study. Morphology investigation with SEM operated in transmission mode showed good BA dispersion forming network-like structure. At the same time, distribution of particles differed for HP14 and OS1 as a result of different interaction in CEO-solvent-particles system. CEO structure obtained via non-hydrolytic sol-gel reaction was verified by 13C and 29Si NMR. In situ monitoring of film curing was performed using RT-IR spectroscopy. A slight increase of final convention degree with particle incorporation was observed in contrast to the considerable decrease of curing efficiency reported previously for similar system. Further, the cured hybrid nanocomposite films were analyzed by TGA and DSC, which revealed impact of surface modifier on thermal stability and glass transition temperature. T2 - Kyiv Conference on Analytical Chemistry: Modern Trends CY - Kyiv, Ukraine DA - 17.09.2018 KW - Cycloalyphatic epoxy oligosiloxane KW - Nanocomposite KW - Boehmite KW - Photocuring PY - 2018 AN - OPUS4-47642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Topolniak, Ievgeniia A1 - Elert, Anna Maria A1 - Knigge, Xenia A1 - Cinar Ciftci, G. A1 - Radnik, Jörg A1 - Sturm, Heinz T1 - Direct laser writing of mussel inspired polydopamine N2 - Polydopamine (PDA) is one of the simplest and most versatile approaches for forming an excellent binding exterior to confer new functionalities to nearly any material surface. Inspired by nature, it mimics the behavior of mussels and can be easily deposited on virtually all types of inorganic and organic substrates, including superhydrophobic surfaces. Moreover, PDA exhibits high potential for surface modification and diversified secondary reactions that makes it extremely interesting for a wide range of application including biomedical field, e.g., drug delivery, adhesives, cell adhesion, biosensing. PDA has undergone significant expansion in its applications and is one of the most attractive areas within the materials field. Nevertheless, PDA integration in microdevices is still constrained by poor spatial and temporal control of excited deposition methods. Herein, we demonstrate a novel maskless approach for PDA micropatterning based on Direct Laser Writing that overcomes present limitations. The pattern is formed upon exposure of the dopamine solution by light produced by tightly-focused fs NIR laser that scans substrate surface accordingly to the selected pattern design. Neither strong oxidants, metal ions nor adjusting pH to alkaline is required by this technique to perform dopamine polymerization. Our method achieves the PDA micropatterns with the spatial resolution of 0.8 µm, at least an order of magnitude smaller than what is possible with other PDA microplanning techniques. Some examples of PDA patterns are shown in Figure 1. The here introduced PDA deposition technique will uniquely unravel applications of polydopamine and other catecholamine-based mussel-inspired materials in various multifunctional systems and microdevices (e.g., MEMS elements, microfluidics). The chemical nature of PDA was confirmed by locally recorded vibrational and x-ray photoelectron spectra. Moreover, the morphology and thickness of PDA microstructure can be controlled by the laser power and scanning velocity revealing the possibility of fabricating the structures with gradient. In most of the applied conditions the increase of the laser intensity and decrease of the scanning velocity would lead to the thicker PDA pattern. Different morphologies from smooth and bulky-like to grain like has been obtained. PDA was produced in the presence of tris buffer, phosphate buffer and DI water only. We also tested the effect of the solution pH applying pH 6.0, 7.0 and 8.5. Furthermore, the effect of antioxidants and purging of the solution with oxygen and nitrogen was investigated. Summarizing, we could see that the structures could be produced in all the given conditions, however their thickness and quality, morphology and roughness would differ. We did not observe negative impact of the antioxidants and nitrogen purging on the performance of PDA build up indicating that the PDA formation mechanism is different to common autooxidation. The current mechanism is based on the interaction of dopamine molecules with the photoinitiator added to solution as active to DLW laser light component. Apart from the glass substrate, we achieved PDA patterning at surfaces of different nature such as polychlorotrifluoroethylene, polydimethylsiloxane, polyethylene terephthalate, silicon wafers, and fluorinated glass coverslips. We also performed facile posts-modification of the PDA surface with protein enzymes like trypsin that was confirmed by XPS. Obtained bioactive pattern could be further integrated in the protein sensing devices. Presented in this work DLW-based microfabrication technique and the possibilities for further PDA surface post-functionalization empowers advanced applications of this material in single-molecule bioassays, sensors and other complex microdevices. T2 - MNE EUROSENSORS CY - Leuven, Belgium DA - 19.09.2022 KW - Polydopamine KW - Two-photon polymerisation KW - Micropatterning PY - 2022 AN - OPUS4-56421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Hallier, Dorothea C. A1 - Dietrich, P. M. A1 - Radnik, Jörg T1 - In-situ monitoring of water dependent DNA and protein radiation damage by near-ambient-pressure XPS N2 - X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. Our results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further. T2 - ICRR 2023 CY - Montreal, Canada DA - 26.08.2023 KW - DNA KW - XPS KW - Proteins KW - Protein KW - G5P KW - Base damage KW - Base loss KW - Cancer treatment KW - DEA KW - DET KW - DNA radiation damage KW - Direct damage KW - Dissociative electron attachment (DEA) KW - Dissociative electron transfer (DET) KW - Dosimetry KW - ESCA KW - Energy deposit KW - Geant4 KW - Geant4-DNA KW - Hydrated DNA KW - Hydrated electron KW - Hydrated electrons KW - Hydration shell KW - Hydroxyl radical KW - Indirect damage KW - Ionisation KW - Ionization KW - LEE KW - Low energy electrons KW - MCS KW - Microdosimetry KW - NAP-XPS KW - Near ambient pressure xray photo electron spectroscopy KW - Net-ionization reaction KW - OH radical KW - PES KW - Particle scattering KW - Prehydrated electron KW - Presolvated electron KW - Quasi-direct damage KW - ROS KW - Radiation damage KW - Radiation therapy KW - Radical KW - Radiolysis KW - Radiotherapy KW - Reactive oxygen species KW - Simulation KW - Single-strand break (SSB) KW - Single-stranded DNA-binding proteins KW - TOPAS KW - TOPAS-nbio KW - TopasMC KW - Xray photo electron spectrocopy PY - 2023 AN - OPUS4-58214 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Kim, C.S. A1 - Ruh, S. W. A1 - Unger, Wolfgang A1 - Radnik, Jörg A1 - Mata-Salazar, J. A1 - Juarez-Garcia, J.M. A1 - Cortazar-Martinez, O. A1 - Herrera-Gomez, A. A1 - Hansen, P.E. A1 - Madesen, J.S. A1 - Senna, C.A. A1 - Archanjo, B.S. A1 - Damasceno, J.C. A1 - Achete, C.A. A1 - Wang, H. A1 - Wang, M. A1 - Windover, D. A1 - Steel, E. A1 - Kurokawa, A. A1 - Fujimoto, T. A1 - Azuma, Y. A1 - Terauchi, S. A1 - Zhang, L. A1 - Jordaan, W.A. A1 - Spencer, S.J. A1 - Shard, A.G. A1 - Koenders, L. A1 - Krumrey, M. A1 - Busch, I. A1 - Jeynes, C. T1 - Thickness measurement of nm HfO2 films N2 - A pilot study for the thickness measurement of HfO2 films was performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study was to ensure the equivalency in the measurement capability of national metrology institutes for the thickness measurement of HfO2 films. In this pilot study, the thicknesses of six HfO2 films with nominal thickness from 1 nm to 4 nm were measured by X-ray Photoelectron Spectroscopy (XPS), X-ray Reflectometry(XRR), X-ray Fluorescence Analysis (XRF), Transmission Electron Spectroscopy (TEM), Spectroscopic Ellipsometry (SE) and Rutherford Backscattering Spectrometry (RBS). The reference thicknesses were determined by mutual calibration of a zero-offset method (Medium Energy Ion Scattering Spectroscopy (MEIS) of KRISS) and a method traceable to the length unit (the average thicknesses of three XRR data except the thinnest film). These reference thicknesses are traceable to the length unit because they are based on the traceability of XRR. For the thickness measurement by XPS, the effective attenuation length of Hf 4f electrons was determined. In the cases of XRR and TEM, the offset values were determined from a linear fitting between the reference thicknesses and the individual data by XRR and TEM. The amount of substance of HfO2, expressed as thickness of HfO2 films (in both linear and areal density units), was found to be a good subject for a CCQM key comparison. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM. KW - Thickness measurements KW - nm films KW - X-ray Photoelectron Spectroscopy KW - Mutual calibration PY - 2021 DO - https://doi.org/10.1088/0026-1394/58/1A/08016 SN - 0026-1394 VL - 58 IS - 1a SP - 08016 PB - IOP Publishing Lt. CY - Bristol AN - OPUS4-54175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohammadifar, E. A1 - Ahmadi, V. A1 - Gholami, M.F. A1 - Oehrl, A. A1 - Kolyvushko, O. A1 - Nie, C. A1 - Donskyi, Ievgen A1 - Herziger, S. A1 - Radnik, Jörg A1 - Ludwig, K. A1 - Böttcher, C. A1 - Rabe, J.P. A1 - Osterrieder, K. A1 - Azab, W. A1 - Haag, R. A1 - Adeli, M. T1 - Graphene-Assisted Synthesis of 2D Polyglycerols as Innovative Platforms for Multivalent Virus Interactions N2 - 2D nanomaterials have garnered widespread attention in biomedicine and bioengineering due to their unique physicochemical properties. However, poor functionality, low solubility, intrinsic toxicity, and nonspecific interactions at biointerfaces have hampered their application in vivo. Here, biocompatible polyglycerol units are crosslinked in two dimensions using a graphene-assisted strategy leading to highly functional and water-soluble polyglycerols nanosheets with 263 ± 53 nm and 2.7 ± 0.2 nm average lateral size and thickness, respectively. A single-layer hyperbranched polyglycerol containing azide functional groups is covalently conjugated to the surface of a functional graphene template through pH-sensitive linkers. Then, lateral crosslinking of polyglycerol units is carried out by loading tripropargylamine on the surface of graphene followed by lifting off this reagent for an on-face click reaction. Subsequently, the polyglycerol nanosheets are detached from the surface of graphene by slight acidification and centrifugation and is sulfated to mimic heparin sulfate proteoglycans. To highlight the impact of the two-dimensionality of the synthesized polyglycerol sulfate nanosheets at nanobiointerfaces, their efficiency with respect to herpes Simplex virus type 1 and severe acute respiratory syndrome corona virus 2 inhibition is compared to their 3D nanogel analogs. Four times stronger in virus Inhibition suggests that 2D polyglycerols are superior to their current 3D counterparts.2D nanomaterials have garnered widespread attention in biomedicine and bioengineering due to their unique physicochemical properties. However, poor functionality, low solubility, intrinsic toxicity, and nonspecific interactions at biointerfaces have hampered their application in vivo. Here, biocompatible polyglycerol units are crosslinked in two dimensions using a graphene-assisted strategy leading to highly functional and water-soluble polyglycerols nanosheets with 263 ± 53 nm and 2.7 ± 0.2 nm average lateral size and thickness, respectively. A single-layer hyperbranched polyglycerol containing azide functional groups is covalently conjugated to the surface of a functional graphene template through pH-sensitive linkers. Then, lateral crosslinking of polyglycerol units is carried out by loading tripropargylamine on the surface of graphene followed by lifting off this reagent for an on-face click reaction. Subsequently, the polyglycerol nanosheets are detached from the surface of graphene by slight acidification and centrifugation and is sulfated to mimic heparin sulfate proteoglycans. To highlight the impact of the two-dimensionality of the synthesized polyglycerol sulfate nanosheets at nanobiointerfaces, their efficiency with respect to herpes Simplex virus type 1 and severe acute respiratory syndrome corona virus 2 inhibition is compared to their 3D nanogel analogs. Four times stronger in virus Inhibition suggests that 2D polyglycerols are superior to their current 3D counterparts. KW - 2D Materials KW - Graphene template KW - Multivalency KW - Polyglycerol KW - Virus inhibition PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527726 DO - https://doi.org/10.1002/adfm.202009003 VL - 31 IS - 32 SP - 2009003 PB - Wiley VCH AN - OPUS4-52772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gawek, Marcel A1 - Madkour, Sherif A1 - Szymoniak, Paulina A1 - Radnik, Jörg A1 - Schönhals, Andreas T1 - Energy Dependent XPS Measurements on Thin Films of a Poly(vinyl methyl ether)/Polystyrene Blend in Dependence on Film Thickness – Concentration Profile on a Nanometer Resolution to Understand the Behavior of Nanofilms N2 - The composition of the surface layer in dependence from the distance of the polymer/air interface in thin films with thicknesses below 100 nm of miscible polymer blends in a spatial region of a few nanometers is not investigated completely. Here, thin films of the blend poly vinyl methyl ether) (PVME)/polystyrene (PS) with a composition of 25/75 wt% are investigated by Energy Resolved X-ray Photoelectron Spectroscopy (ER-XPS) at a synchrotron storage ring using excitation energies lower than 1 keV. By changing the energy of the photons the information depth is varied in the range from ca. 1 nm to 10 nm. Therefore, the PVME concentration could be estimated in dependence from the distance of the polymer/air interface for film thicknesses below 100 nm. Firstly, as expected for increasing information depth the PVME concentration decreases. Secondly, it was found that the PVME concentration at the surface has a complicated dependence on the film thickness. It increases with decreasing film thickness until 30 nm where a maximum is reached. For smaller film thicknesses the PVME concentration decreases. A simplified layer model is used to calculate the effective PVME concentration in the different spatial regions of the surface layer. KW - Energy dependent XPS KW - Soft X-ray KW - Thin films PY - 2021 DO - https://doi.org/10.1039/d1sm00656h VL - 17 IS - 29 SP - 6985 EP - 6994 PB - The Royal Chemical Society AN - OPUS4-53039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Pflüger, Mika A1 - Velasco-Vélez, Juan-Jesús A1 - Sahre, Mario A1 - Radnik, Jörg A1 - Bernicke, Michael A1 - Bernsmeier, Denis A1 - Hodoroaba, Vasile-Dan A1 - Krumrey, Michael A1 - Strasser, Peter A1 - Kraehnert, Ralph A1 - Hertwig, Andreas T1 - Operando electrochemical spectroscopic ellipsometry: Material properties of highly active mesoporous IrOx films revealed under realistic OER conditions N2 - Hydrogen production via water electrolysis will be an essential cornerstone in development of sustainable, fossil-free fuel and chemical production on a global scale. The activity and stability of each catalyst is highly dependent on the properties of the coating, i.e., phase composition, crystallinity, accessible surface area, and many other factors. The key to developing improved catalysts is a better understanding of the relationships between their performance, stability, and physicochemical properties. However, these relationships can be complex and are also strongly influenced by the reaction environment. Therefore, operando analysis of the catalyst material during catalysis at realistic potentials and current densities is highly desirable. However, many analytical techniques cannot be applied in liquid environments at realistic potentials and current densities. We propose environmental ellipsometric analysis in a dedicated electrochemical flow cell as a method to evaluate gas evolution reactions operando under realistic working conditions. Figure 1 illustrates schematically the developed technique. Key factors to success are highly active model-type catalysts, a suitable sample environment, and a deep understanding of the appropriate model development, as well as concise cross validation with numerous other analytical techniques. The method was developed and validated by analyzing a calcination series (300 – 600 °C) of mesoporous templated IrOx films ex-situ and operando under oxygen evolution reaction (OER) conditions. The employed environmental electrochemical spectroscopic ellipsometric (ECSE) analysis revealed during OER the change of optical and electronic properties, i.e. the dielectric functions, resistivity and band-to-band transitions (p-d band transitions). Film thickness and porosity were validated by means of scanning electron microscopy (SEM), X-ray reflectometry (XRR) or ellipsometric porosimetry (EP), electrical and electronic properties by means of conductivity measurements, X-ray photoelectron spectroscopy (XPS) or UV-Vis-NIR absorption spectroscopy. The electronic structures of the catalysts from valence electron energy loss spectra (VEELS) derived from ε1 and ε2 from SE measurements reveal a direct correlation with electrochemical activities in OER. In the presentation reversible and irreversible potential-dependent changes of the catalyst properties during operation will be discussed along with the dynamics of gas formation, transport and dissolution at different potentials. T2 - 11th Workshop Ellipsometry (WSE 11) CY - Steyr, Austria DA - 06.09.2021 KW - Ectrocatalysis KW - Mesoporous iridium oxide films KW - Non-destructive operando analysis KW - Oxygen evolution reaction KW - Spectroscopic ellipsometry PY - 2021 AN - OPUS4-53915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Singh, Chandan A1 - Riedel, Soraya A1 - Konthur, Zoltán A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg A1 - Schenk, J. A1 - Schneider, Rudolf T1 - Functionalized Titanium Carbide Nanosheets based Biosensor for Detection of the SARS-CoV-2 Nucleocapsid Protein N2 - MXenes are a new family of two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides discovered in 2011. Among many reported family members, titanium carbide is the most widely studied and explored due to the optimized synthesis conditions and promising characteristics like good mechanical strength, solution processability, and excellent conductivity. Here, we report the development of an electrochemical biosensor involving the amine-functionalized Few-Layered-Titanium Carbide Nanosheets and monoclonal antibodies against the SARS-CoV-2 nucleocapsid protein (anti-SARS-CoV-2 mAb) to design a point-of-care device for detection of the SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 NP) antigen. T2 - SALSA's Make and Measure 2022 CY - Berlin, Germany DA - 15.09.2022 KW - MXenes KW - Titanium Carbide Nanosheets KW - Biosensors KW - Electrochemistry PY - 2022 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. AN - OPUS4-55856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - López de Ipina, J.-M. A1 - Arevalillo, A. A1 - Martín, A. A1 - Caillard, B. A1 - Marcoulaki, E. A1 - Aguerre- Charol, O. A1 - van Duuren-Stuurman, B. A1 - Hodoroaba, Vasile-Dan A1 - Viitanen, A.-K. A1 - Witters, H. A1 - Vercauteren, S. A1 - Persson, K. A1 - Bard, D. A1 - Evans, G. A1 - Jensen, K.A. A1 - Himly, M. A1 - Scalbi, S. A1 - Papin, A. A1 - Le Bihan, O. A1 - Kanerva, T. A1 - Tirez, K. A1 - Frijns, E. A1 - Niga, P. A1 - Eleftheriadis, K. A1 - Travlos, A. A1 - Geppert, M. A1 - Himly, M. A1 - Radnik, Jörg A1 - Kuchenbecker, Petra A1 - Resch-Genger, Ute A1 - Fraboulet, I. A1 - Bressot, C. A1 - Rissler, J. A1 - Gaucher, R. A1 - Binotto, G. A1 - Krietsch, Arne A1 - Braun, A. A1 - Abenet, S. A1 - Catalan, J. A1 - Verstraelen, S. A1 - Manier, N. A1 - Manzo, S. A1 - Fransman, S. A1 - Queron, J. A1 - Charpentier, D. A1 - Taxell, D. A1 - Säämänen, A. A1 - Brignon, J.-M. A1 - Jovanovic, A. A1 - Bisson, M A1 - Neofytou, P. T1 - EC4Safenano - Catalogue of Services N2 - The publicly available document encapsulates the first version of the Catalogue of Services of the future EC4Safenano Centre (CoS 2019). The CoS 2019 is structured in 12 Service Categories and 27 Service Topics, for each of the 12 categories considered. This architecture configures a 12 x 27 matrix that allows ordering the potential EC4Safenano offer in 324 types of services/groups of services. Each type of service/group of services is described, in a simple and friendly way, by means of a specific service sheet: the EC4Safenano - Service Data Sheet (EC4-SDS). These EC4-SDSs allow structuring and summarizing the information of each service, providing the customer with a concise view of characteristics of the service and also the contact details with the service provider. The CoS 2019 deploys a map of services consisting of a set of 100 EC4-SDSs, covering 7 of the 12 Service Categories and 17 of the 27 Service Topics. The harmonization of services is visualized as a future necessary step in EC4Safenano, in order to strengthen the offer and provide added value to customers with a growing offer of harmonized services in future versions of the CoS. The information contained in this document is structured in 3 main sections, as follows: • Catalogue structure. This section describes in short the main characteristics of the CoS 2019. • Catalogue content. This section represents the core part of the document and encapsulates the set of 100 SDSs displaying the offer proposed by the CoS 2019. • Online Catalogue. This section describes the resources implemented by EC4Safenano to facilitate the on-line consultation of the CoS 2019 by customers and other interested parties. KW - Nano-safety KW - Analytical services KW - Nanomaterials KW - Catalogue of services KW - EC4SafeNano KW - European Centre PY - 2021 UR - https://ec4safenano.eu-vri.eu/Public/Guidance SP - 1 EP - 72 PB - EU-VRi – European Virtual Institute for Integrated Risk Management CY - Stuttgart, Germany AN - OPUS4-52943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Topolniak, Ievgeniia A1 - Hodoroaba, Vasile-Dan A1 - Pfeifer, Dieter A1 - Braun, Ulrike A1 - Sturm, Heinz T1 - Impact of Boehmite nanoparticles on the curing behaviour and thermal properties of cycloaliphatic-epoxy oligosiloxane hybrid N2 - UV-curing coatings are nowadays widely used due to their unique advantages. High-quality coatings can be obtained at short curing times and low temperatures so that thermal stress to the substrate is minimised. Photocured Cycloaliphatic-Epoxy Oligosiloxane (CEO) resin was reported to be used as encapsulation material for organic electronics. However, further reinforcement of CEO film properties is desired to achieve requested device lifetime. In this work we introduced Boehmite nanoparticles (BA) into CEO matrix in order to modify the film properties and study the main changes of the material behaviour with regard to its photocuring kinetics, thermal stability and glass transition. Particular interest was focused on the role of particle surface in nanocomposite properties. Hence, BA particles without (HP14) and with organic surface modifier (OS1) at different loadings (up to 10 wt%) were applied in this study. Morphology investigation with SEM operated in transmission mode showed good BA dispersion forming network-like structure. At the same time, distribution of particles differed for HP14 and OS1 as a result of different interaction in CEO-solvent-particles system. CEO structure obtained via non-hydrolytic sol-gel reaction was verified by 13C and 29Si NMR. In situ monitoring of film curing was performed using RT-IR spectroscopy. No significant modification of final convention degree with particle incorporation was observed in contrast to considerable decrease of curing efficiency reported previously for similar system by Esposito et al.,2008. Further, cured hybrid nanocomposite films were analysed by TGA and DSC, which revealed impact of surface modifier on film thermal properties. T2 - E-MRS CY - Warsaw, Poland DA - 15.09.2018 KW - Cycloalyphatic epoxy oligosiloxane KW - Nanocomposite KW - Boehmite KW - DSC KW - TGA KW - UV-curing PY - 2018 AN - OPUS4-47643 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Chemello, Giovanni A1 - Hodoroaba, Vasile-Dan A1 - Howe, T. A1 - Vyas, N. A1 - Reed, B. P. A1 - Pollard, A. J. A1 - Clifford, C. A. T1 - Reliable Chemical Characterization Protocols for Industrial Graphene-Related Materials N2 - Since its isolation, graphene has received growing attention from academia and industry due to its unique properties. Promising opportunities for applications are discussed in different field like electronics and optoelectronics, detection, and sensing devices, biosystems or chemical and environmental corrosion inhibition. Here, functionalization with elements like oxygen, nitrogen or fluorine can broaden the application, for example in composite materials. However, lack of generally accepted operation procedures hinders the commercialization, the so-called “what is my material” barrier. Therefore, first efforts were done to develop common, reliable, and reproducible ways to characterize the morphological and chemical properties of the industrially produced material. In this contribution, our efforts in the development of reliable chemical characterizations protocols for functionalized graphene are presented. An ISO standard for the chemical characterization of graphene-related (GRM) is under development with X-ray photoelectron spectroscopy (XPS) having a prominent role. With its information depth of around 10 nm, which is the similar length scale as the thickness of particles of 2D materials consisting of a few monolayers, XPS seems to be highly suitable for the quantitative analysis of (functionalized) GRM. Thereby, different sample preparation methods like pressing the powders onto adhesive tapes, into recesses, or into solid pellets result in inconsistencies in the quantification. Furthermore, different morphologies like stacks of graphene layers (left figure) or irregular particles (right figure) lead to different analysis results for the chemical composition. For the validation of the quantification with XPS and the further development of standards an international interlaboratory comparison was initiated under the head of the “Versailles Project on Advanced Materials and Standards” (VAMAS). First results are reported showing the suitability of the protocols. Finally, the XPS results are compared with the elemental composition results obtained after quantification with energy-dispersive X-ray spectroscopy (EDS) as a fast analytical method which is usually combined with electron microscopy. T2 - nanoSAFE 2023 CY - Grenoble, France DA - 05.06.2023 KW - X-ray photoelectron spectroscopy KW - Functionalized graphene KW - Interlaboratory comparison KW - VAMAS PY - 2023 AN - OPUS4-57652 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Chemello, Giovanni A1 - Hodoroaba, Vasile-Dan A1 - Howe, T. A1 - Vyas, N. A1 - Reed, B.P. A1 - Pollard, A.J. A1 - Clifford, C.A. T1 - Reliable chemical characterization of industrial graphene related materials N2 - International standards describing reliable protocols will facilitate the commercialization of graphene and related 2D materials. One physico-chemical key property next to flake size and thickness is the chemical composition of the material. Therefore, an ISO standard is under development with X-ray photoelectron spectroscopy having a prominent role. With its information depth of around 10 nm which is the similar length scale as the thickness as of particles of 2D materials consisting of a few monolayer XPS seems to be highly suitable for this purpose. Different sample preparation methods like pressing the powders onto adhesive tapes, into recesses, or into solid pellets result in inconsistencies in the quantification. For the validation of the quantification with XPS an interlaboratory comparison was initiated under the auspice of the “Versailles Project on Advanced Materials and Standards” (VAMAS). First results confirm that the sample preparation method (pellet vs. powder) influences the quantification results clearly. Considering this effect, a good agreement of the results from the different participants were observed. Similar results were observed for raw, N- and F-functionalized graphene. T2 - Graphene CY - Manchester, England, UK DA - 27.06.2023 KW - X-ray photoelectron spectroscopy KW - Functionalized graphene KW - Interlaboratory comparison KW - VAMAS PY - 2023 AN - OPUS4-57895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Chemello, Giovanni A1 - Radnik, Jörg T1 - Accurate Measurement of Size of Graphene Oxide Flakes by Scanning Electron Microscopy (SEM) N2 - Accurate characterisation of the morphology (size) and chemistry of graphene-related 2D materials (GR2M) is key in understanding their extraordinary functionalities. Hence, not only the tailoring of these functionalities aiming at applications of increased-performance becomes possible, but also the correlation of the physico-chemical properties with the understanding of the potential toxicity eventually enables a safe and sustainable development of the GR2M for new applications. Whilst AFM and Raman Spectroscopy are recommended to measure the thickness of GO flakes, Scanning Electron Microscopy (SEM) is the most suited method to assess their lateral size, which varies between tens of µm down to below 100 nm. In this paper, procedures for the accurate determination of lateral size of graphene oxide (GO) flakes by SEM are presented. The prerequisite for accurate flake size analysis is the proper sample preparation, i.e. deposition of ideally isolated flakes on a substrate, with the flakes being unfolded, non-overlapped, parallel with the substrate, and having a high coverage density. Examples of optimum image caption conditions and image analysis procedures will be presented. The size descriptors and their measurement are described in the context of the corresponding analysis approach: i) length and width of the flakes with a quick and rough, but robust procedure, and ii) exact contouring of the flakes as part of a highly accurate, but more time-consuming measurement approach. The possibility of application of automated image analysis is discussed as the alternative to the manual flakes analysis. T2 - Graphene 2023 CY - Manchester, UK DA - 27.07.2023 KW - Graphene oxide KW - SEM KW - Size KW - Standardisation PY - 2023 UR - https://www.grapheneconf.com/2023/index.php AN - OPUS4-57910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Radnik, Jörg A1 - Chemello, Giovanni A1 - Knigge, Xenia A1 - Al-Sabbgh, Dominik A1 - Hodoroaba, Vasile-Dan T1 - XPS, HAXPES, XRD and SEM datasets of functionalized graphene nanoplateletes N2 - The datasets from (Hard Energy) X-ray photoelectron spectroscopy, X-ray diffraction and Scanning Electron Microsopy are related to the publication G. Chemello, X. Knigge, D. Ciornii, B.P. Reed, A.J. Pollard, C.A. Clifford, T. Howe, N. Vyas, V.-D. Hodoroaba, J. Radnik "Influence of the morphology on the functionalization of graphene nanoplatelets analyzed by comparative photoelectron spectroscopy with soft and hard X-rays" Advanced Materials Interfaces (2023), DOI: 10.1002/admi.202300116. KW - Graphene related 2D materials KW - X-ray photoelectron spectroscopy KW - Hard-energy X-ray photoelectron spectroscopy KW - Scanning electron microscopy KW - Powder X-ray diffraction PY - 2023 DO - https://doi.org/10.5281/zenodo.7956497 PB - Zenodo CY - Geneva AN - OPUS4-57898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neamtu, Mariana A1 - Nadejde, C. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf A1 - Ababei, G. A1 - Panne, Ulrich T1 - Photocatalysis of γ-cyclodextrin-functionalised Fe3O4 nanoparticles for degrading Bisphenol A in polluted waters N2 - The efficiency, relatively low cost and eco-friendly nature of hydrogen peroxide-assisted photocatalysis treatment procedures are significant advantages over conventional techniques for wastewater remediation. Herein, we evaluate the behaviour of g-cyclodextrin (g-CD) immobilised on either bare or chitosan (CS)–functionalised Fe3O4 nanoparticles, for photodegrading Bisphenol A (BPA) in ultrapure water and in real wastewater samples. The BPA removal efficiencies with Fe3O4/g-CD and Fe3O4/CS/g-CD were compared with those of Fe3O4/b-CD, and were monitored under UVA irradiation at near-neutral pH. The addition of H2O2 at low concentrations (15 mmol L-1) significantly increased BPA photodegradation in the presence of each nanocomposite. The highest catalytic activity was shown by both Fe3O4/g-CD and Fe3O4/CS/g-CD nanocomposites (,60 and 27%BPA removal in ultrapure water and real wastewater effluent, respectively). Our findings reveal the superior performance of g-CD-functionalised Fe3O4 relative to that of Fe3O4/b-CD. The use of CD-based nanocomposites as photocatalytic materials could be an attractive option in the pre- or post-treatment stage of wastewaters by advanced oxidation processes before or after biological treatment. KW - Photooxidation KW - Sonochemical synthesis KW - Wastewater PY - 2019 DO - https://doi.org/10.1071/EN18181 SN - 1448-2517 VL - 16 IS - 2 SP - 125 EP - 136 PB - CSIRO Publishing CY - Clayton South AN - OPUS4-48316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Topolniak, Ievgeniia A1 - Elert, Anna Maria A1 - Knigge, Xenia A1 - Ciftci, G. C. A1 - Radnik, Jörg A1 - Sturm, Heinz T1 - High precision micropatterning of polydopamine by Multiphoton Lithography N2 - Mussel-inspired polydopamine (PDA) initiated a multifunctional modification route that leads to the generation of novel advanced materials and their applications. However, existing PDA deposition techniques still exhibit poor spatial control, have a very limited capability of micropatterning and do not allow to locally tune PDA topography. Herein, we demonstrate PDA deposition based on Multiphoton Lithography (MPL) that enables full spatial and temporal control with nearly total freedom of patterning design. Using MPL, we achieve 2D microstructures of complex design with pattern precision of 0.8 μm without the need of a photomask or stamp. Moreover, this approach permits adjusting the morphology and thickness of the fabricated microstructure within one deposition step, resulting in a unique tunability of materials properties. The chemical composition of PDA is confirmed and its ability for protein enzyme immobilization is demonstrated. This work presents a new methodology for high precision and complete control of PDA deposition, enabling PDA incorporation in applications where fine and precise local surface functionalization is required. Possible applications include multicomponent functional elements and devices in microfluidics or lab-on-a-chip systems. KW - Multiphoton lithography KW - Polydopamine KW - Micropatterning PY - 2022 DO - https://doi.org/10.1002/adma.202109509 VL - 34 IS - 18 SP - e2109509 PB - Wiley online library AN - OPUS4-54535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tu, Z. A1 - Donskyi, Ievgen A1 - Qiao, H. A1 - Zhu, Z. A1 - Unger, Wolfgang A1 - Hackenberger, C. P. R. A1 - Chen, W. A1 - Adeli, M. A1 - Haag, R. T1 - Graphene Oxide-Cyclic R10 Peptide Nuclear Translocation Nanoplatforms for the Surmounting of Multiple-Drug Resistance N2 - Multidrug resistance resulting from a variety of defensive pathways in Cancer has become a global concern with a considerable impact on the mortality associated with the failure of traditional chemotherapy. Therefore, further research and new therapies are required to overcome this challenge. In this work, a cyclic R10 peptide (cR10) is conjugated to polyglycerol-covered nanographene oxide to engineer a nanoplatform for the surmounting of multidrug resistance. The nuclear translocation of the nanoplatform, facilitated by cR10 peptide, and subsequently, a laser-triggered release of the loaded doxorubicin result in efficient anticancer activity confirmed by both in vitro and in vivo experiments. The synthesized nanoplatform with a combination of different features, including active nucleus-targeting, highloading capacity, controlled release of cargo, and photothermal property, provides a new strategy for circumventing multidrug resistant cancers. KW - Graphen Oxide KW - Nanoplatform KW - Cancer PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510061 DO - https://doi.org/10.1002/adfm.202000933 VL - 30 IS - 35 SP - 2000933 PB - Wiley VCH AN - OPUS4-51006 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Photoelectron spectroscopy N2 - A short introduction into the basics of Photoelectron Spectroscopy with the focus on surface sensitivity and applications is presented. T2 - Industrietreffen im Forschungs- und Innovationszentrum (FIZ) der BMW Group CY - Munich, Germany DA - 09.01.2018 KW - XPS KW - ESCA KW - Surface analytics PY - 2018 AN - OPUS4-43737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neamtu, Mariana A1 - Nadejde, C. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf A1 - Verestiuc, L. A1 - Panne, Ulrich T1 - Functionalized magnetic nanoparticles: Synthesis, characterization, catalytic application and assessment of toxicity N2 - Cost-effective water cleaning approaches using improved Treatment technologies, for instance based on catalytic processes with high activity catalysts, are urgently needed. The aim of our study was to synthesize efficient Fenton-like photo-catalysts for rapid degradation of persistent organic micropollutants in aqueous medium. Iron-based nanomaterials were chemically synthesized through simple procedures by immobilization of either iron(II) oxalate (FeO) or iron(III) citrate (FeC) on magnetite (M) nanoparticles stabilized with polyethylene glycol (PEG). Various investigation techniques were performed in order to characterize the freshly prepared catalysts. By applying advanced oxidation processes, the effect of catalyst dosage, hydrogen peroxide concentration and UV-A light exposure were examined for Bisphenol A (BPA) conversion, at laboratory scale, in mild conditions. The obtained results revealed that BPA degradation was rapidly enhanced in the presence of low-concentration H2O2, as well as under UV-A light, and is highly dependent on the surface characteristics of the catalyst. Complete photo-degradation of BPA was achieved over the M/PEG/FeO catalyst in less than 15 minutes. Based on the catalytic performance, a hierarchy of the tested catalysts was established: M/PEG/FeO > M/PEG/FeC > M/PEG. The results of cytotoxicity assay using MCF-7 cells indicated that the aqueous samples after treatment are less cytotoxic. KW - Bisphenol A KW - Magnetic nanocatalyst KW - Endocrine disruptor KW - Nanoparticle KW - Photodegradation KW - Fenton PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-448297 DO - https://doi.org/10.1038/s41598-018-24721-4 SN - 2045-2322 VL - 8 SP - Article 6278, 1 EP - 11 PB - Springer Nature CY - London AN - OPUS4-44829 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weigert, Florian A1 - Müller, A. A1 - Häusler, I. A1 - Geißler, Daniel A1 - Skroblin, D. A1 - Unger, Wolfgang A1 - Radnik, Jörg A1 - Resch-Genger, Ute T1 - Combining HR‑TEM and XPS to elucidate the core–shell structure of ultrabright CdSe/CdS semiconductor quantum dots N2 - Controlling thickness and tightness of surface passivation shells is crucial for many applications of core–shell nanoparticles (NP). Usually, to determine shell thickness, core and core/shell particle are measured individually requiring the availability of both nanoobjects. This is often not fulfilled for functional nanomaterials such as many photoluminescent semiconductor quantum dots (QD) used for bioimaging, solid state lighting, and display technologies as the core does not show the applicationrelevant functionality like a high photoluminescence (PL) quantum yield, calling for a whole nanoobject approach. By combining high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS), a novel whole nanoobject approach is developed representatively for an ultrabright oleic acid-stabilized, thick shell CdSe/CdS QD with a PL quantum yield close to unity. The size of this spectroscopically assessed QD, is in the range of the information depth of usual laboratory XPS. Information on particle size and monodispersity were validated with dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) and compared to data derived from optical measurements. In addition to demonstrating the potential of this novel whole nanoobject approach for determining architectures of small nanoparticles, the presented results also highlight challenges faced by different sizing and structural analysis methods and method-inherent uncertainties. KW - Photoluminescence KW - Single particle KW - Microscopy KW - Particle architecture KW - Thickness KW - SAXS KW - Shell KW - XPS KW - TEM KW - Semiconductor KW - Quantum dot KW - Photophysics KW - Quantum yield PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517911 DO - https://doi.org/10.1038/s41598-020-77530-z VL - 10 IS - 1 SP - 20712 PB - Springer Nature AN - OPUS4-51791 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 - Hünger, K.-J. A1 - Kositz, M. A1 - Danneberg, M. A1 - Radnik, Jörg T1 - Enrichment of aluminium in the near‐surface region of natural quartzite rock after aluminium exposure N2 - Alkali–silica reaction (ASR) is an ongoing problem that causes damage to concrete constructions and reduces their durability. Therefore, minimizing this undesired reaction is of great interest for both safety and economic reasons. Additives containing high aluminium content are very effective in reducing the release of silica and enhancing the durability of concrete; however, the mechanism for this effect is still under discussion. In this study, an enrichment of aluminium in the near‐surface region was observed for natural quartzite rock after storage in Al (OH)3 and metakaolin as aluminium sources, from which we conclude that the formation of aluminosilicate sheets of a few nanometres inhibits the silica release; this hypothesis is supported by high‐resolution spectra of Al 2p, Si 2p and O 1s. KW - Alkali-silica reaction KW - Quartzite rock KW - X-ray photoelectron spectroscopy PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519394 DO - https://doi.org/10.1002/sia.6918 SN - 0142-2421 SP - 1 EP - 7 PB - Wiley VCH AN - OPUS4-51939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Donskyi, Ievgen A1 - Nie, C. A1 - Ludwig, K. A1 - Trimpert, J. A1 - Ahmed, R. A1 - Quaas, E. A1 - Achazi, K. A1 - Radnik, Jörg A1 - Adeli, M. A1 - Haag, R. A1 - Osterrieder, K. T1 - Graphene Sheets with Defined Dual Functionalities for the Strong SARS-CoV-2 Interactions N2 - Search of new strategies for the inhibition of respiratory viruses is one of the urgent health challenges worldwide, as most of the current therapeutic agents and treatments are inefficient. Severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) has caused a pandemic and has taken lives of approximately two Million people to date. Even though various vaccines are currently under development, virus, and especially its spike glycoprotein can mutate, which highlights a Need for a broad-spectrum inhibitor. In this work, inhibition of SARS-CoV-2 by graphene platforms with precise dual sulfate/alkyl functionalities is investigated. A series of graphene derivatives with different lengths of aliphatic chains is synthesized and is investigated for their ability to inhibit SARS-CoV-2 and feline coronavirus. Graphene derivatives with long alkyl chains (>C9) inhibit coronavirus replication by virtue of disrupting viral envelope. The ability of these graphene platforms to rupture viruses is visualized by atomic force microscopy and cryogenic electron microscopy. A large concentration window (10 to 100-fold) where graphene platforms display strongly antiviral activity against native SARS-CoV-2 without significant toxicity against human cells is found. In this concentration range, the synthesized graphene platforms inhibit the infection of enveloped viruses efficiently, opening new therapeutic and metaphylactic avenues against SARS-CoV-2. KW - Graphene KW - Graphene-based polyglycerol sulfates KW - SARS-CoV2 inhibitor KW - Virucidality PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520858 DO - https://doi.org/10.1002/smll.202007091 VL - 17 IS - 11 SP - 7091 PB - Wiley VCH AN - OPUS4-52085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wurzler, Nina A1 - Sobol, Oded A1 - Altmann, Korinna A1 - Radnik, Jörg A1 - Özcan Sandikcioglu, Özlem T1 - Preconditioning of AISI 304 stainless steel surfaces in the presence of flavins—Part I: Effect on surface chemistry and corrosion behavior N2 - Stainless steel AISI 304 surfaces were studied after a mild anodic polarization for oxide growth in the presence and absence of two derivatives of vitamin B2 (riboflavin and flavin mononucleotide) that can be secreted by metal‐reducing bacteria and act as a chelating agent for iron species. The alterations in oxide chemistry were studied by means of surface‐sensitive techniques such as X‐ray photoelectron spectroscopy and time‐of‐flight secondary ion mass spectrometry analysis. The complementary electrochemical characterization revealed a preferential growth of an oxide/hydroxide iron‐rich film that is responsible for an altered pit initiation and nucleation behavior. These findings suggest that as the corrosion behavior is determined by the interplay of the chemical and electronic properties, only a mild anodic polarization in the presence of redox‐active molecules is able to alter the chemical and electronic structure of the passive film formed on stainless steel AISI 304. This helps to achieve a profound understanding of the mechanisms of microbially influenced corrosion (MIC) and especially the possible effects of the redox‐active biomolecules, as they may play an important role in the corrosion susceptibility of stainless steel surfaces. KW - Corrosion KW - Stainless steel KW - Surface analysis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528117 DO - https://doi.org/10.1002/maco.202012191 VL - 72 IS - 6 SP - 974 EP - 982 PB - Wiley AN - OPUS4-52811 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hesse, R. A1 - Denecke, R. A1 - Radnik, Jörg T1 - Testing and validating the improved estimation of the spectrometer-transmission function with UNIFIT 2022 N2 - Recent developments of X-ray photoelectron spectroscopy using excitation energies different from the usual lab-sources Mg Kα and Al Kα, thus covering larger and different kinetic energy ranges, require more flexible approaches for determining the transmission function than the well-established ones using reference spectra. Therefore, the approach using quantified peak areas (QPA) was refined allowing a more precise estimation of the transmission function. This refinement was tested by comparing the results obtained with the new version with former calculations. Furthermore, the obtained transmission function was validated by comparing the results with a transmission function using the reference spectrum of polyethylene. Additionally, an ionic liquid was used as reference for estimating the transmission function at the energy resolved HE-SGM beamline at BESSY II. Comparison between the measured and stoichiometric composition shows that a transmission function was determined, which allows a reasonable quantification. KW - XPS KW - Quantification KW - Software UNIFIT 2022 KW - Synchrotron radiation KW - Transmission function IERF PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551671 DO - https://doi.org/10.1002/sia.7131 SN - 0142-2421 SP - 1 EP - 7 PB - Wiley-VCH AN - OPUS4-55167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Kersting, R. A1 - Hagenhoff, B. A1 - Bennett, Francesca A1 - Ciornii, Dmitri A1 - Hodoroaba, Vasile-Dan T1 - Comprehensive characterization of Al-coated titania nanoparticles with electron microscopy and surface chemical analytics N2 - The wide use of nanoforms with at least one dimension below 100 nm in our daily life requires a detailed knowledge of their physicochemical properties which are needed for risk assessment or quality control. Therefore, a comprehensive characterization of these properties was considered as relevant including: chemical composition, crystallinity, particle size, particle shape, surface chemistry, and specific surface area (SSA). We want to discuss, how Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA) in the version with energy dispersive X-ray spectroscopy (EDS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS) can contribute to gain comprehensive insights into the nature of the nanoparticles. SEM results provide the particle size and shape (distribution). A quick identification of the main chemical elements present in the sample can be obtained with EDS, whereas XPS allows a more detailed chemical identification of the small nanoparticles below 20 nm or of the near-surface region of larger particles. ToF-SIMS is even much more surface-sensitive and leads to a deeper understanding of the surface chemistry of the nanoparticles. As exemplary samples, two Al-coated TiO2 samples in nanopowder form were chosen from the JRC repository, capped either with a hydrophilic or a hydrophobic organic shell. A focus of our case study was to show, how reliable, reproducible and traceable data can be obtained. Therefore, each step in the workflow of sample investigation must be described in detail. For the most of these steps, well-established standards are available. Usually, the conditions of the particular measurements with each analysis method are saved as meta-data in the common file formats. But other factors like sample preparation and data reduction approaches may influence the result of the investigations in a significant manner and must be described often in a separate file (as a protocol) together with the data file. For sensitive materials like nanoobjects, the preparation of the sample influences the results crucially, e.g. measured as suspension or as powders. Furthermore, data reduction like selection of relevant peaks in spectra or particles in images, background subtraction, peak deconvolution, models for the quantification of the spectra must be considered in the interpretation of the results ideally with associated individual measurement uncertainties. Only a detailed description of all these factors allows to obtain a comprehensive characterization with reliable, reproduceable and traceable data. Examples of standardized procedures of measurement or on data reduction will be highlighted. We thank for the funding from the European Unions’s Horizon 2020 for the project NanoSolveIt (grant agreement No. 814572) and for the project NANORIGO (grant agreement No. 814530). T2 - E-MRS Spring Meeting CY - Online meeting DA - 31.05.2021 KW - Scanning Electron Microscopy KW - Energy dispersive X-ray spectroscopy KW - Time-of-Flight Secondary Ion Mass Spectrometry KW - X-ray Photoelectron Spectroscopy KW - Titania nanoparticles PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527486 AN - OPUS4-52748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Page, T.M. A1 - Nie, C. A1 - Neander, L. A1 - Povolotsky, T.L. A1 - Sahoo, A.K. A1 - Nickl, Philip A1 - Adler, J.M. A1 - Bawadkji, O. A1 - Radnik, Jörg A1 - Achazi, K. A1 - Ludwig, K. A1 - Lauster, D. A1 - Netz, R.R. A1 - Trimpert, J. A1 - Kaufer, B. A1 - Haag, R. A1 - Donskyi, Ievgen T1 - Functionalized Fullerene for Inhibition of SARS-CoV-2 Variants N2 - As virus outbreaks continue to pose a challenge, a nonspecific viral inhibitor can provide significant benefits, especially against respiratory viruses. Polyglycerol sulfates recently emerge as promising agents that mediate interactions between cells and viruses through electrostatics, leading to virus inhibition. Similarly, hydrophobic C60 fullerene can prevent virus infection via interactions with hydrophobic cavities of surface proteins. Here, two strategies are combined to inhibit infection of SARS-CoV-2 variants in vitro. Effective inhibitory concentrations in the millimolar range highlight the significance of bare fullerene’s hydrophobic moiety and electrostatic interactions of polysulfates with surface proteins of SARS-CoV-2. Furthermore, microscale thermophoresis measurements support that fullerene linear polyglycerol sulfates interact with the SARS-CoV-2 virus via its spike protein, and highlight importance of electrostatic interactions within it. All-atom molecular dynamics simulations reveal that the fullerene binding site is situated close to the receptor binding domain, within 4 nm of polyglycerol sulfate binding sites, feasibly allowing both portions of the material to interact simultaneously. KW - Covalent functionalization KW - Fullerene KW - SARS-CoV 2 KW - Sulfated materials KW - Virus inhibition PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568672 DO - https://doi.org/10.1002/smll.202206154 SN - 1613-6810 SP - 1 EP - 8 PB - Wiley VCH AN - OPUS4-56867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jungnickel, R. A1 - Mirabella, Francesca A1 - Stockmann, Jörg Manfred A1 - Radnik, Jörg A1 - Balasubramanian, K. T1 - Graphene‑on‑gold surface plasmon resonance sensors resilient to high‑temperature annealing N2 - Gold films coated with a graphene sheet are being widely used as sensors for the detection of label-free binding interactions using surface plasmon resonance (SPR). During the preparation of such sensors, it is often essential to subject the sensor chips to a high-temperature treatment in order to ensure a clean graphene surface. However, sensor chips used currently, which often use chromium as an adhesion promoter, cannot be subjected to temperatures above 250 °C, because under such conditions, chromium is found to reorganize and diffuse to the surface, where it is easily oxidized, impairing the quality of SPR spectra. Here we present an optimized preparation strategy involving a three-cycle tempering coupled with chromium (oxide) etching, which allows the graphene-coated SPR chips to be annealed up to 500 °C with little deterioration of the surface morphology. In addition, the treatment delivers a surface that shows a clear enhancement in spectral response together with a good refractive index sensitivity. We demonstrate the applicability of our sensors by studying the kinetics of avidin–biotin binding at different pH repeatedly on the same chip. The possibility to anneal can be exploited to recover the original surface after sensing trials, which allowed us to reuse the sensor for at least six cycles of biomolecule adsorption. KW - Surface plasmon resonance KW - Graphene KW - Sensing KW - Surface regeneration PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564585 DO - https://doi.org/10.1007/s00216-022-04450-4 SN - 1618-2642 SP - 1 EP - 7 PB - Springer AN - OPUS4-56458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stockmann, Jörg M. A1 - Radnik, Jörg A1 - Bütefisch, S. A1 - Busch, I. A1 - Passiu, C. A1 - Rossi, A. A1 - Unger, Wolfgang T1 - A new reference material for the determination of the Field of View of Small Area XPS N2 - Small Area Photoelectron Spectroscopy (XPS) is a powerful tool for investigating small surface features. It is often unclear, if the signal in the spectrum is an unwanted contamination of the Field of View (FoV) or is it originated from outside. The reason is, that XPS-spectra are affected by beam shapes. Scheithauer proposed to measure Pt apertures of different diameters and normalize the Pt4f count rate by a second measurement on the Pt metal. New reference materials were developed and tested in the VAMAS TWA2 A22 Project. T2 - ECASIA 2019 CY - Dresden, Germany DA - 15.09.2019 KW - Reference material KW - Small Area XPS KW - Selected Area XPS KW - Small Spot XPS KW - Field of Analysis PY - 2019 AN - OPUS4-49236 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neamtu, M. A1 - Nadejde, C. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf A1 - Panne, Ulrich T1 - Singlet oxygen generation potential of porphyrin-sensitized magnetite nanoparticles: Synthesis, characterization and photocatalytic application N2 - Singlet oxygen generation potential of two novel free-base-porphyrin photocatalysts was investigated. The freebase-porphyrin-sensitized Fe3O4 magnetic nanoparticles (MNPs) were tested for the degradation of the model pollutant Bisphenol A (BPA) in aqueous solution, for the first time. MNPs with either cubic or spherical shape were synthesized using the sonochemical approach, followed by sensitizing with photoactive 4,4′,4′′,4′′′- (Porphine-5,10,15,20-tetrayl)tetrakis(benzoic acid) (TCPP). The resulted photocatalysts were characterized in detail by scanning and transmission electron microscopy, Brunauer–Emmett–Teller analysis, spectral techniques and vibrating sample magnetometry. The electron spin resonance experiments have confirmed the high activity of the photocatalysts through the efficient formation of singlet oxygen in solution. The optimum operational parameters for BPA degradation were established as follows: 1.0 μmol L−1 BPA, 1.0 g L−1 of photocatalyst, 100 μmol L−1 H2O2, under UVA irradiation. In these conditions, the results for both photocatalysts revealed that after only 10 min of reaction, over 64% and ca. 90% of BPA have been removed from solution in the absence and presence of H2O2, respectively. Whereas after 60 minutes of treatment, only 24% of BPA in real wastewater effluent samples were removed under UVA irradiation in the absence of H2O2, showing the high complexity of real wastewater. Moreover, both photocatalysts were successfully used for BPA removal in three consecutive runs, without significant loss of catalytic features. KW - Bisphenol A KW - Magnetpartikel KW - Photooxidation KW - Singulettsauerstoff KW - TEM KW - SEM KW - Brunauer-Emmett-Teller KW - Katalysator KW - Abwasser KW - ESR PY - 2018 DO - https://doi.org/10.1016/j.apcatb.2018.03.079 SN - 0926-3373 VL - 232 SP - 553 EP - 561 PB - Elsevier B.V. CY - Amsterdam, NL AN - OPUS4-45267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stockmann, Jörg M. A1 - Radnik, Jörg A1 - Bütefisch, S. A1 - Busch, I. A1 - Weimann, T. A1 - Passiu, C. A1 - Rossi, A. A1 - Unger, Wolfgang T1 - A new test specimen for the determination of the field of view of small-area X-ray photoelectron spectrometers N2 - Small-area/spot photoelectron spectroscopy (SAXPS) is a powerful tool for the investigation of small surface features like microstructures of electronic devices, sensors or other functional surfaces, and so forth. For evaluating the quality of such microstructures, it is often crucial to know whether a small signal in a spectrum is an unwanted contamination of the field of view (FoV), defined by the instrument settings, or it originated from outside. To address this issue, the d80/20 parameter of a line scan across a chemical edge is often used. However, the typical d80/20 parameter does not give information on contributions from the long tails of the X-ray beam intensity distribution or the electron-optical system as defined by apertures. In the VAMAS TWA2 A22 project “Applying planar, patterned, multi-metallic samples to assess the impact of analysis area in surface-chemical analysis,” new test specimen was developed and tested. The here presented testing material consists of a silicon wafer substrate with an Au-film and embedded Cr circular and square spots with decreasing dimensions from 200 μm down to 5 μm. The spot sizes are traceable to the length unit due to size measurements with a metrological SEM. For the evaluation of the FoV, we determined the Au4f intensities measured with the center of the FoV aligned with the center of the spot and normalized to the Au4f intensity determined on the Au-film. With this test specimen, it was possible to characterize, as an example, the FoV of a Kratos AXIS Ultra DLD XPS instrument. T2 - ECASIA 2019 CY - Dresden, Germany DA - 15.09.2019 KW - Field of view KW - Reference material KW - Selected area XPS KW - Small-area XPS KW - Small-spot XPS PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509902 DO - https://doi.org/10.1002/sia.6831 SN - 1096-9918 VL - 52 IS - 12 SP - 890 EP - 894 PB - John Wiley & Sons Ltd AN - OPUS4-50990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - 1-Propyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide (Solarpur®) analyzed by hard x-ray photoelectron spectroscopy N2 - 1-Propyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide (Solarpur®), an ionic liquid was purchased from Merck (formerly Sigma Aldrich), was analyzed using hard x-ray photoelectron spectroscopy (HAXPES). The liquid is UHV stable, vertically and laterally homogeneous, and is easy to clean; thus, it can be used as a reference material. The HAXPES spectra of Solarpur® obtained using monochromatic Cr Kα radiation at 5414.8 eV include a survey scan, high-resolution spectra of C 1s, O 1s, N 1s, S 2p, S 1s, S 2s, F 1s, and S KLL. KW - HAXPES KW - Hard x-ray photoelectron spectroscopy KW - Ionic liquid KW - Solarpur PY - 2021 DO - https://doi.org/10.1116/6.0001414 VL - 28 IS - 2 SP - 1 EP - 8 PB - AVS: Science & Technology of Materials, Interfaces, and Processing AN - OPUS4-54113 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - von der Au, Marcus A1 - Dietrich, P. M. A1 - Radnik, Jörg A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia T1 - The comparison of the corrosion behavior of the CrCoNi medium entropy alloy and CrMnFeCoNi high entropy alloy N2 - This work presents the determination of the corrosion characteristics of CrCoNi (medium entropy alloy) and CrMnFeCoNi (high entropy alloy) in 0.1 M NaCl and 0.1 M H2SO4. The morphology and chemical composition of the oxide layers formed on CrCoNi and CrMnFeCoNi were comparatively analyzed by scanning Kelvin probe microscopy (SKPFM) and scanning electron microscopy (SEM) and supported with chemical analysis by means of inductively coupled plasma mass spectrometry (ICP-MS) and X-Ray photoelectron spectroscopy (XPS). The analysis of the 3p core level peaks showed that the oxide layer (native and after anodic passivation) on CrCoNi consisted mainly of Cr oxides, while the oxide layer on CrMnFeCoNi was primarily composed of a mixture of Cr and Fe oxides. In addition, XPS was utilized to assess the oxide layer thicknesses. These results were compared to the thicknesses obtained by means of electrochemical impedance spectroscopy (EIS), with both approaches yielding values up to about 4 nm depending on the electrolyte and the alloy. Cyclic polarization measurements indicated superior corrosion resistance of CrCoNi in both aqueous environments compared to CrMnFeCoNi, as well as to AISI 304 stainless steel. KW - Medium entropy alloy KW - High entropy alloy KW - SKPFM KW - XPS KW - Passivation KW - Corrosion PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559902 DO - https://doi.org/10.1016/j.apsusc.2022.154171 SN - 0169-4332 VL - 601 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-55990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagl, Dorothee A1 - Szymoniak, Paulina A1 - Hodoroaba, Vasile-Dan A1 - Sturm, Heinz T1 - The effect of boehmite nanoparticles (gamma‐AlOOH) on nanomechanical and thermomechanical properties correlated to crosslinking density of epoxy N2 - We show that complex physical and chemical interactions between boehmite nanoparticles and epoxy drastically affect matrix properties, which in the future will provide tuning of material properties for further optimization in applications from automotive to aerospace. We utilize intermodulation atomic force microscopy (ImAFM) for probing local stiffness of both particles and polymer matrix. Stiff particles are expected to increase total stiffness of nanocomposites and the stiffness of polymer should remain unchanged. However, ImAFM revealed that stiffness of matrix in epoxy/boehmite nanocomposite is significantly higher than unfilled epoxy. The stiffening effect of the boehmite on epoxy also depends on the particle concentration. To understand the mechanism behind property alteration induced by boehmite nanoparticles, network architecture is investigated using dynamic mechanical thermal analysis (DMTA). It was revealed that although with 15 wt% boehmite nanoparticles the modulus at glassy state increases, crosslinking density of epoxy for this composition is drastically low. KW - Crosslinking density KW - Epoxy KW - Intermodulation KW - Atomic force microscopy KW - Nanomechanical properties KW - Boehmite nanoparticles PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-476050 DO - https://doi.org/10.1016/j.polymer.2018.12.054 SN - 0032-3861 SN - 1873-2291 VL - 164 SP - 174 EP - 182 PB - Elsevier AN - OPUS4-47605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang A1 - Müller, Anja A1 - Heinrich, Thomas A1 - Kunz, Valentin A1 - Nymark, P. A1 - Radnik, Jörg T1 - Chemical characterization of nanoparticles by PCA-assisted ToF-SIMS: a) Core-shell character, b) transformation and c) grouping studies N2 - This talk was given within the scope of the SIMS-22 conference in October 2019 in Kyoto (Japan). It deals with the surface analytical investigation of nanoparticles by PCS-assisted ToF-SIMS. This technique is applicable to core-shell nanoparticles, in order to distinguish a complete encapsulation from an incomplete encapsulation of the core by the shell material. Furthermore, the depletion process of organic nanoparticle coatings caused by UV-weathering is investigated. Finally, the significance of grouping studies for nanomaterials research and risk assessment is demonstrated. T2 - The 22nd International Conference on Secondary Ion Mass Spectrometry (SIMS-22) CY - Kyoto, Japan DA - 20.10.2019 KW - Nanoparticles KW - ToF-SIMS KW - Principal component analysis (PCA) PY - 2019 AN - OPUS4-50075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Giovannozzi, A. A1 - Rossi, A. A1 - Kovac, J. A1 - Ekar, J. A1 - Goenaga-Infante, H. A1 - Clarkson, C. A1 - Clifford, C. A1 - Cant, D. A1 - Minelli, C. A1 - Reithofer, M. A1 - Lindner, G. A1 - Venzago, C. A1 - Bohmer, N. A1 - Drexler, C.-P. A1 - Schedler, U. A1 - Thiele, T. A1 - Lechart, F. A1 - Kästner, B. A1 - Sjövall, P. A1 - Johnston, L. A1 - Tan, Gunnar A1 - Radnik, Jörg T1 - Standardised Measurements of Surface Functionalities on Nanoparticles N2 - Engineered nanoparticles (NPs) with various chemical compositions and surface functionalities are routinely fabricated for industrial applications such as medical diagnostics, drug delivery, sensing, catalysis, energy conversion and storage, opto-electronics, and information storage which improve the quality of life and European prosperity. NP function, performance, interaction with biological species, and environmental fate are largely determined by their surface functionalities. Standardized repeatable surface characterization methods are therefore vital for quality control of NPs, and to meet increasing concerns regarding their safety. Therefore, industry, regulatory agencies, and policymakers need validated traceable measurement methods and reference materials. This calls for fit-for-purpose, validated, and standardized methods, and reference data and materials on the surface chemistry of engineered NPs. Here, we present a concept for the development of such standardized measurement protocols utilizing method cross-validation and interlaboratory comparisons (ILCs) with emphasis on both advanced measurement methods such as quantitative Nuclear Magnetic Resonance (qNMR), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) and cost-efficient, non-surface specific methods like optical assays and electrochemical titration methods. T2 - European Partnership on Metrology 2023 Review Conference CY - Amsterdam, Netherlands DA - 07.11.2023 KW - Surface chemistry KW - Quality assurance KW - Traceability PY - 2023 AN - OPUS4-59142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Matthews, Lauren T1 - Breaking the Wall of Rapid Diagnostics N2 - In this short presentation the diagnostics, biomarkers and analysis are interrelated. The specificity and sensitivity of the DNA structures as well as the high-throughput option of the nanopore sensing are discussed. T2 - Falling Walls Lab Berlin-Adlershof CY - Berlin, Germany DA - 21.09.2023 KW - Nanopipettes KW - Sensing KW - Diagnosis KW - DNA structures PY - 2023 AN - OPUS4-60450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - John, Elisabeth A1 - Weise, Matthias A1 - Stockmann, Jörg M. A1 - Radnik, Jörg A1 - Sahre, Mario A1 - Lange, Thorid A1 - Hodoroaba, Dan T1 - Towards a high-entropy alloy thin-film reference material N2 - Analyzing materials composed of multiple elements with spectroscopic techniques such as X-ray Photoelectron Spectroscopy (XPS), Auger-Electron Spectroscopy (AES) or Electron Probe Microanalysis (EPMA), can be challenging due to spectral overlap. Moreover, each analytical method introduces its own set of challenges, e.g., the strong secondary fluorescence effect for neighbor elements in EPMA, thus, making the accurate elemental quantification in such materials difficult. When the material is available as thin film, additional constraints are inherently present. To provide a reference material for these analytical challenges high entropy alloys (HEAs) are excellent candidates. Currently, there is no thin film reference available containing more than 2 elements. Unlike traditional alloys, which typically consist of one or two main elements and smaller amounts of secondary elements, HEAs are characterized by the presence of multiple principal elements in almost equal proportions. This unique composition results in a high degree of disorder at the atomic level, leading to exceptional mechanical, physical, and often unexpected properties. HEAs have garnered significant attention in materials science and engineering due to their potential applications in a wide range of industries, from aerospace and automotive to electronics and renewable energy. For the preparation of a dedicated thin film reference material, we have chosen to prepare HEAs by magnetron sputtering, since it is not associated with elemental segregation that may occur due to the high configurational entropy of HEAs, which promotes atomic rearrangements. Our goal was to prepare films with a homogeneous thickness and defined chemical composition to be analyzed by various methods dedicated to surface analysis. The material, consisting of titanium, chromium, manganese, iron, and nickel was deposited as film on silicon substrates - to our knowledge the first HEA thin film of this type reported in literature. A set of different thickness of the films was chosen, on the one hand to facilitate the analysis with different techniques, and on the other side to evaluate the limitations of the respective methods. The films morphology was characterized as prepared by SEM followed by the analysis of their 2D compositional homogeneity by EDX, XRF, ToF-SIMS and XPS. in-depth chemical composition was evaluated by ToF-SIMS and AES. The outcomes of analyzing the initial batches of films will be presented. T2 - European Conference on Applications Surface and Interface Analysis (ECASIA 2024) CY - Gothenburg, Sweden DA - 10.06.2024 KW - High-entropy alloy KW - Thin film KW - Magnetron sputtering PY - 2024 AN - OPUS4-60455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madbouly, Loay Akmal A1 - Mrkwitschka, Paul A1 - Schusterbauer, Robert A1 - Stockmann, Jörg Manfred A1 - Jones, E. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - Chemical Analysis of Functionalized Graphene along the Production Chain N2 - Graphene has been commercialized for over a decade. It is usually used in the form of suspensions or inks. In this study, we analyze the starting material for commercial functionalized graphene (FG) solutions and inks as well as their starting material (FG powders) using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), energy-dispersive X-Ray spectroscopy (EDX), time of flight secondary ion mass spectrometry (ToF-SIMS) and Auger electron spectroscopy (AES). Graphene was functionalized with fluorine, oxygen, ammonia, and carboxylic acid. Our results suggest a significant effect of water and commercial resins on the presence as well as the morphological behavior of graphene and associated functionalized group. For example, XPS analysis shows some significant differences between the solutions and the starting materials (powders). These changes can be explained by the location of the functionalization at the outer most surface as indicated by Chemello et al. T2 - European Conference on Applications of Surface and Interface Analysis (ECASIA 2024) CY - Gothenburg, Sweden DA - 09.06.2024 KW - Functionalized graphene KW - Commercial graphene KW - Graphene inks PY - 2024 AN - OPUS4-60446 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madbouly, Loay Akmal A1 - Mrkwitschka, Paul A1 - Schusterbauer, Robert A1 - Schusterbauer, Jörg Manfred A1 - Jones,, E. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - Chemical Analysis of Functionalized Graphene along the Production Chain N2 - Graphene has been commercialized for over a decade. It is usually used in the form of suspensions or inks. In this study, we analyze the starting material for commercial functionalized graphene (FG) solutions and inks as well as their starting material (FG powders) using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), energy-dispersive X-Ray spectroscopy (EDX), time of flight secondary ion mass spectrometry (ToF-SIMS) and Auger electron spectroscopy (AES). Graphene was functionalized with fluorine, oxygen, ammonia, and carboxylic acid. Our results suggest a significant effect of water and commercial resins on the presence as well as the morphological behavior of graphene and associated functionalized group. For example, XPS analysis shows some significant differences between the solutions and the starting materials (powders). These changes can be explained by the location of the functionalization at the outer most surface as indicated by Chemello et al. T2 - MaterialsWeek 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Functionalized graphene KW - Commercial graphene KW - Graphene inks PY - 2024 AN - OPUS4-60448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul A1 - Abram, Sarah-Luise A1 - Rühle, Bastian A1 - Hodoroaba, Vasile-Dan T1 - Correlative analysis with electron microscopy applied in different operating modes (SEM, STEM-in-SEM and TEM) for the accurate morphological characterisation of non-spherical fine nanoparticles N2 - Electron microscopy applied in different operating modes, e.g., SEM, TEM or STEM-in-SEM, is the gold standard method to investigate the exact size and shape of individual nanoparticles. However, when fine nanoparticles with a non-monodisperse size distribution and non-spherical shapes are analysed, achieving an accurate result is challenging. Deviations in size measurements of more than 10% may occur. Understanding of the contrasts and sensitivities characteristic to the individual operating modes of an electron microscope is key in interpreting and evaluating quantitatively the measurement uncertainties needed for an eventual certification of specific nanoparticles via traceable results. Further, beyond the pure measurement, the other components in the analysis workflow with significant impact on the overall measurement uncertainties are the sample preparation and the image segmentation. In the present study the same areas of selected iron oxide fine nanoparticles (<25 nm) as reference nanomaterial (candidate) prepared on substrate for electron microscopy imaging are analysed correlatively with SEM, STEM-in-SEM and TEM with respect to their size and shape distribution. Individual significant measurement uncertainties are discussed, e.g., the sensitivity of secondary electron detectors of InLens-type to the surface morphology, particularly to the presence of an ultrathin organic coating or signal saturation effects on the particle edges, to electron beam exposure, to surface contamination, or the selection of the threshold for image segmentation. Another goal of this study is to establish a basis of analysis conditions which shall guarantee accurate results when both manual and particularly (semi-)automated segmentation approaches are applied. Advantages as well as limitations of the use of different electron microscopy operating modes, applied individually and correlatively, are highlighted. T2 - E-MRS 2024 Spring Meeting CY - Strasbourg, France DA - 27.05.2024 KW - Nanoparticles KW - Electron Microscopy KW - Metrology KW - Imaging KW - Reference materials PY - 2024 AN - OPUS4-60436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul A1 - Hodoroaba, Vasile-Dan A1 - Pellegrino, Francesco A1 - Rossi, Andrea A1 - Jones, Elliot T1 - Towards automated analysis of the lateral dimensions of graphene oxide flakes N2 - Graphene and graphene-oxide (GO) are advanced materials which – similar to other graphene-related 2D materials (GR-2M) - are already used for instance in catalysis processes, biomedical applications, in inks and resins, or as composite materials for the aviation industry. The lateral/structural characterization of graphene oxide (GO) flakes is a challenging task, with steps like sample preparation, representative image selection and exact determination of the particle size distribution of well-defined size and shape descriptors being crucial for an accurate analysis. To ensure that safe-by-design principles are met within the various application fields, the commercial material must be thoroughly characterized and specified through well-known and standardized procedures. GO flakes with different degrees of complexity were selected to assess the requirements for an accurate evaluation of their physico-chemical properties. These samples show inherent features with complex nanoscale characteristics such as porosity and edge roughness; further, the lateral size (quantified via equivalent circular diameter (ECD), minimum Feret and maximum Feret) of isolated and overlapping particles deposited on a substrate span over several orders of magnitude (nano to micron scale). The samples showed different degrees of agglomeration (and possible aggregation) with sizes ranging between submicron to a few tens of micrometers. One focus is the automated segmentation and evaluation of images obtained by electron microscopy. The GO samples appear translucent with well-defined contrast between single and overlapping flakes both with the secondary electron detector of type InLens as well as with SEM in the transmission mode (STEM) utilizing a dedicated sample holder. To this end it is of utmost importance for the accurate image segmentation to carefully select thresholds both manually and through semi-automatic approaches using well-known threshold algorithms such as “IsoData” and pre-defined segmentation applications such as the ParticleSizer software package. Further specific challenges in identifying and extracting key features of selected graphene oxide flakes are being discussed and approaches towards accurate and representative characterization are presented. T2 - E-MRS 2024 Spring Meeting CY - Strasbourg, France DA - 27.05.2024 KW - Graphene /-oxide KW - Morphology KW - Electron microscopy KW - Imaging KW - Advanced materials PY - 2024 AN - OPUS4-60435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Matthews, Lauren A1 - Sahre, Mario A1 - Hesse, R. A1 - Schusterbauer, Robert A1 - Grant, M. A1 - Agudo Jacome, Leonardo A1 - Albrecht, T. A1 - Hodoroaba, Vasile-Dan T1 - Approaches to Surface Analysis of Modified Quartz Nanopipettes N2 - Nanopipettes are a type of solid-state nanopore with needle-like geometry. Their applications range from imaging, sensing, diagnostics, and use as injectors. The response of nanopipette sensors is highly dependent on the size, geometry and chemical properties of the sensing region. As they are increasingly tuned and modified for specific analytes, a better understanding of the surface chemistry and morphology of the inner channel is necessary. With the aim of developing a comprehensive approach for characterisation of such nanopipettes, this research focuses on combining surface-sensitive analysis methods with advanced sample preparation techniques. Quartz substrates were modified by gas phase silanization, a well-utilised technique in the field to enhance performance of nanopipettes, and further functionalised with a metal bis thiolate complex, to aid in chemical analysis. The sample characterisation involved scanning electron microscopy (SEM), low-energy dispersive x-ray spectroscopy (EDX), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and Auger electron spectroscopy (AES). Using focused ion beam (FIB) milling under gentle conditions, the inner surface of quartz nanopipettes was exposed whilst preserving the integrity of the overall structure (see figure). Owing to the challenging analysis conditions, modification and analysis of flat quartz substrates has been performed in parallel for optimisation purposes. The results demonstrate the first steps towards full characterisation of nanopipettes at the nanoscale, notably with access to the inner channel. The methods used here can be applied to gain further understanding of the response of these sensors to complex analytes and allow for the study of different surface functionalisations at the all-important sensing region. T2 - European Conference on Applications of Surface and Interface Analysis (ECASIA 2024) CY - Gothenburg, Sweden DA - 09.06.2024 KW - Quartz nanopipettes KW - Nanopipette modification KW - Silanization KW - Surface analysis KW - Focussed ion beam PY - 2024 AN - OPUS4-60447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Salzmann, Christoph A1 - Pellegrino, F. A1 - Durand, B. A1 - Taché, O. A1 - Zurutuza, A. T1 - Role of Sample Preparation for Accurate and Automated Morphological Analysis of Nanoparticles proven in Interlaboratory Comparison Exercises 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 - MaterialsWeek 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Nanoparticles KW - VAMAS KW - Interlaboratory comparison KW - Sample preparation KW - Nanoparticle concentration PY - 2024 AN - OPUS4-60453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Sachse, René A1 - Matjacic, L. A1 - McMahon, G. A1 - Bernicke, M. A1 - Bernsmeier, D. A1 - Kraehnert, R. A1 - Hertwig, Andreas T1 - Chemical Nanoscale Analysis of Mesoporous Mixed IrOx-TiOx Thin Films N2 - Porous films play an important role particularly in energy applications like photovoltaics, electrolysis or batteries. Thin film properties such as thickness, chemical composition, crystallinity of the framework, and porosity define the activity of the porous films. The accurate morpho-chemical characterisation of mesoporous thin films is a challenging analytical task which requires the consideration of new analytical approaches based on the combination of data of different methods able to address the structure and chemical composition at the nanoscale. In this contribution we characterise thin mesoporous iridium-titanium mixed oxide film properties by Electron Probe Microanalysis (EPMA) with Energy-Dispersive X-ray Spectroscopy (EDS) at an SEM applied in a dedicated “thin film analysis” approach. Thus, the film mass deposition, film thickness and the film density can be determined. Further, by dividing the measured film density to an assumed (theoretical) metal oxide framework (skeletal) density, the thin film porosity can be extracted, too. In order to assess the homogeneity of the thin film properties like the chemical composition, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Auger Electron Spectrometry are applied in the depth profiling mode, so that possible in-depth gradients are detected. Lateral inhomogeneities in the chemical composition and structure of the thin mesoporous films are also identified by applying the same methods in the line-scan or mapping mode, which can be further combined with in-depth sputtering for 3D information. The role of the spatial resolution of the analytical methods considered, which can go down well below 100 nm, will be highlighted. T2 - MaterialsWeek 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Thin films KW - Mesoporous KW - IR oxide KW - Ti oxide KW - Porosity PY - 2024 AN - OPUS4-60452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Matthews, Lauren A1 - Sahre, Mario A1 - Hesse, R. A1 - Schusterbauer, Robert A1 - Grant, M. A1 - Agudo Jacome, Leonardo A1 - Albrecht, T. A1 - Hodoroaba, Vasile-Dan T1 - Approaches to Surface Analysis of Modified Quartz Nanopipettes N2 - Nanopipettes are a type of solid-state nanopore with needle-like geometry. Their applications range from imaging, sensing, diagnostics, and use as injectors. The response of nanopipette sensors is highly dependent on the size, geometry and chemical properties of the sensing region. As nanopipettes are increasingly tuned and modified for specific analytes, a better understanding of the surface chemistry and morphology of the inner channel is necessary. For exploring these effects, quartz nanopipettes were modified by gas phase silanization, a well-utilised technique in the field to enhance performance of nanopipettes, and further functionalised with a metal bis thiolate complex, to aid in chemical analysis. The inner channel of the sensing region was exposed with focused ion beam (FIB) milling as a dedicated sample preparation method for nanoscale surface analysis. The sample characterisation involved scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and low-energy energy dispersive x-ray spectroscopy (EDX). The results demonstrate the first steps towards full characterisation of nanopipettes at the nanoscale, notably with access to the inner channel. The methods used here can be applied to gain further understanding of the response of these sensors to complex analytes, and allow for the study of different surface functionalisation at the all-important sensing region. T2 - 2024 Spring Meeting of the European Materials Research Society (E-MRS) CY - Strasbourg, France DA - 27.05.2024 KW - Nanopipettes KW - FIB KW - Surface analysis KW - Surface modification KW - Silanisation PY - 2024 AN - OPUS4-60449 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Measurement of Lateral Dimensions of Particles & Flakes (2D) by Imaging Methods N2 - An overview with the basics of size and shape measurement of particles and 2D structures according to established methodologies (and popular imaging processing software packages) with imaging techniques is given. Main descriptors are explained based on practical cases are determined interactively at the flipchart. T2 - MaterialsWeek 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Nanoparticles KW - 2D materials KW - Lateral dimensions KW - ISO KW - Imaging PY - 2024 AN - OPUS4-60454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Matthews, Lauren T1 - Rapid Desease Monitoring with Resistive-Pulse Sensing in Nanopipettes N2 - Following parts of the research project as proceeded at University of Birminngham are presented: Translocation, Experiments, Synthesis of DNA Structures, Antibody, Biomarker, Binding. Following works have been carried out at BAM: High Resolution Electron Microscopy, Dedicated Sample Preparation, Surface Analysis Methods. T2 - UoB-BAM Chemistry Theme Meeting CY - Online meeting DA - 15.05.2024 KW - Nanopipettes KW - Sensing KW - Diagnosis KW - Surface analysis PY - 2024 AN - OPUS4-60451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Interlaboratory comparisons as tool in advanced materials characterisation N2 - Interlaboratory comparisons (ILCs) are an important tool for the validation of characterisation methods, and, herwith, a prerequisite for standardisation. The "Versailles Project on Advanced Materials and Standards" offers a framework for performing such ILCs: (i) TiO2 nanoparticles using ToF-SIMS, and (ii) the chemical composition of functionalized graphene using XPS. The results of both ILCs underline the importance of sample preparation for the measured results. T2 - NanoMeasure France Meeting CY - Online meeting DA - 07.06.2024 KW - Standardisation KW - Validation KW - Interlaboratory comparison KW - Graphene related 2D materials KW - Titania nanoparticles PY - 2024 AN - OPUS4-60532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Hodoroaba, Vasile-Dan A1 - Fontanges, R. A1 - Delvallée, A. A1 - Deumer, J. A1 - Salzmann, C. A1 - Crouzier, L. A1 - Gollwitzer, C. A1 - Klein, T. A1 - Koops, R. A1 - Sebaihi, N. A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Artous, S. A1 - Taché, O. A1 - Feltin, N. T1 - Report on full algorithm sequences for nanoparticle detection and size measurement as developed on both a physical basis and by machine learning N2 - he main objective of the nPSize project is to improve the measurement capabilities for nanoparticle size based on both measurement methods traceable to SI units and new reference materials. Two basic approaches have been used in order to develop measurement procedures resulting in traceable results of the nanoparticle size distribution: physical modelling for the methods used in the project (TSEM, SEM, AFM and SAXS) and machine learning. Physical modelling: In this part, the physical models associated with different shape measurements for the techniques TSEM, SEM, AFM and SAXS have been collected and further developed with the aim to simulate the resulting signal as measured by the individual methods. Uncertainties and traceability associated with each model were investigated and evaluated. In the following, the progress on these physical models is reported for each individual method. Machine Learning modelling: The aim of this part is to use machine learning to enable automatic measurement of nanoparticle shape from expert a-priori information only. No physical model will be used as a-priori information in this task. The accuracy and traceability of the size results obtained by each technique will be analyzed and compared with the physical modelling. A machine learning database will then be used to create automatic detection algorithms. KW - Nanoparticles KW - Particle size distribution KW - SEM KW - TSEM KW - TEM KW - SAXS KW - AFM PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546531 DO - https://doi.org/10.5281/zenodo.5807864 SP - 1 EP - 20 PB - Zenodo CY - Geneva AN - OPUS4-54653 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chen, Z. A1 - Perez, J. P. H. A1 - Smales, Glen Jacob A1 - Blukis, R. A1 - Pauw, Brian Richard A1 - Stammeier, J. A. A1 - Radnik, Jörg A1 - Smith, A. J. A1 - Benning, L. G. T1 - Impact of organic phosphates on the structure and composition of short-range ordered iron nanophases N2 - Organic phosphates (OP) are important nutrient components for living cells in natural environments, where they readily interact with ubiquitous iron phases such as hydrous ferric oxide, ferrihydrite (FHY). FHY partakes in many key bio(geo)chemical reactions including iron-mediated carbon storage in soils, or iron-storage in living organisms. However, it is still unknown how OP affects the formation, structure and properties of FHY. Here, we document how β-glycerophosphate (GP), a model OP ligand, affects the structure and properties of GP–FHY nanoparticles synthesized by coprecipitation at variable nominal molar P/Fe ratios (0.01 to 0.5). All GP–FHY precipitates were characterized by a maximum solid P/Fe ratio of 0.22, irrespective of the nominal P/Fe ratio. With increasing nominal P/Fe ratio, the specific surface area of the GP–FHY precipitates decreased sharply from 290 to 3 m2 g−1, accompanied by the collapse of their pore structure. The Fe–P local bonding environment gradually transitioned from a bidentate binuclear geometry at low P/Fe ratios to monodentate mononuclear geometry at high P/Fe ratios. This transition was accompanied by a decrease in coordination number of edge-sharing Fe polyhedra, and the loss of the corner-sharing Fe polyhedra. We show that Fe(III) polymerization is impeded by GP, and that the GP–FHY structure is highly dependent on the P/Fe ratio. We discuss the role that natural OP-bearing Fe(III) nanophases have in biogeochemical reactions between Fe–P and C species in aquatic systems. KW - Organic phosphates KW - Iron nanophases KW - Scattering KW - Diffraction KW - Nanomaterials KW - Coprecipitation KW - Carbon storage PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599399 DO - https://doi.org/10.1039/d3na01045g SN - 2516-0230 SP - 1 EP - 13 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-59939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Ermilova, Elena A1 - Hülagü, Deniz T1 - Determining Material Properties with Spectroscopic Ellipsometry N2 - In this lecture, an introduction will be given on Spectroscopic Ellipsometry, what quantities can be obtained with it, and how we use it in ELENA and other projects to determine functional parameters of thin layers at the nanoscale. T2 - Summer school ELENAM : metrology at the nanoscale CY - Fréjus, France DA - 02.06.2024 KW - Thin Layers KW - Ellipsometry KW - Nanotechnology KW - Electrical Paramters PY - 2024 AN - OPUS4-60247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fernandez-Poulussen, D. A1 - Hodoroaba, Vasile-Dan A1 - Drobne, D. A1 - Novak, S. A1 - Kranjc, E. A1 - Pellegrino, F. A1 - Gullumian, M. A1 - Jones, E. A1 - Hardy, B. A1 - Valsami-Jones, E. A1 - Jurkschat, K. A1 - van der Zande, M. T1 - Holistic, reliable and practical Characterization Framework for Graphene Family Materials, a correlated approach including Imaging based techniques N2 - ACCORDs is an Horizon Europe project working in the development of an imaging-based characterization framework (ACCORDs framework) for the holistic correlative assessment of Graphene Family Materials (GFMs) as a representative of 2D nanomaterials (NMs) to assess and predict 2D NMs health and environmental risks. The ACCORDs framework will operationalise safe and sustainable by design (SSbD) strategies proposed in past or ongoing H2020 projects or within OECD by correlating low-, medium-, and high-resolution physico-chemical-biological imaging-based methods with non-imaging methods in a tiered approach. ACCORDs will deliver the ACCORDs framework and user guidance, new imaging-based characterisation methods, reference in vitro tests, new reference 2D NMs for different matrices, a new minimum information reporting guideline for FAIR data sharing and reuse of images as well as an atlas with reference images for diagnostics of compromised safety of GFMs/GFM products. The new guidelines and standard proposals will be submitted to standardisation bodies to allow creation of regulatory ready products. The novelty of ACCORDs is in translating the principles of medical imaging-based diagnostics to 2D material hazard diagnostics. ACCORDs will accelerate industrial sectors in the area of aviation, marine construction, drone production, flexible electronics, photovoltaics, photocatalytics and print inks-based sensors. The value ACCORDs proposes to the graphene industry are practical, easy, imaging-based tools for GFM quality monitoring next to the production line with a possibility to be correlated with advanced highresolution imaging characterization methods in case hazard i.e. deviation from controls (benchmark values) are diagnosed. The ACCORDs framework and tools will contribute to the European Green Deal by addressing the topic: “Graphene: Europe in the lead” and to a new European strategy on standardization, released on 2nd February, 2022. T2 - MaterialsWeek 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Graphene KW - Graphene-related 2D materials KW - SSbD KW - Imaging KW - ACCORDs PY - 2024 AN - OPUS4-60573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Hielscher-Hofinger, S. A1 - Rietz, U. A1 - Stockmann, Jörg M. T1 - Materials testing using centrifuge technology a journey through time from 2004 to 2024 N2 - This presentation provides an overview of materials testing using centrifuge technology in the period from 2004 to 2024. The development, the proof of concept, the functional principle, various operating modes as well as applications and examples are shown. T2 - ICDAMT 2024 CY - Berlin, Germany DA - 10.06.2024 KW - Centrifuge technology KW - Materials testing KW - Centrifugal adhesion testing KW - Tensile and cmpressive stress testing PY - 2024 AN - OPUS4-60541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Chemello, Giovanni A1 - Reed, B.P. A1 - Marchesini, S. A1 - Pollard, A.J. A1 - Clifford, C.A. T1 - Reliable measurements of the chemical composition of graphene-related 2D materials with X-ray photoelectron spectroscopy N2 - Graphene and related 2D materials (GR2Ms) are now entering an exciting phase of commercialization and use in products. Graphene nanoplatelets (GNPs) can be obtained in rather large quantities, but the properties of these industrially produced powders can vary depending on the production method, and even from batch to batch. Understanding and optimizing the surface chemistry of GNPs, modified through chemical functionalization processes is crucial, because it affects their dispersibility in solvents and matrices for the purpose of embedding them into real-world products. Therefore, reliable and repeatable measurements of the surface chemistry of functionalized GNPs are an important issue for suppliers as well as users of these materials. To address these concerns, international documentary ISO standards for measurement methodologies are under development which incorporate protocols that are becoming widely accepted in the community. Recently, it was shown that pelletizing led to lower average O/C atomic ratios than those measured for powders [1]. In another study, the influence of the morphology on the degree of functionalization was shown [2]. As expected, a higher degree of functionalization was detected for smaller GNPs. The functionalization was located at the outermost surfaces of the GNPs by comparing experiments using photoelectron with soft (Al Kα, 1.486 keV) and hard X-rays (Cr Kα, 5.405 keV). Therefore, it is important for those using GNPs to understand both the physical and chemical properties of these particles, when considering their use in different applications. The next step for reliable characterization protocols was the realization of an interlaboratory comparison under the auspices of VAMAS (Versailles Project on Advanced Materials and Standards) with 22 participating laboratories from all over the world. Samples of oxygen-, nitrogen-, and fluorine- functionalized GNPs were provided to the participants along with a measurement protocol. Participants were asked to prepare the samples as powders on a tape, powders in a sample holder recess, or as pellets. The lower measured O/C ratio reported for pelletized samples [1] was confirmed. The lowest scattering of the results was observed for the powders measured in the recess (Fig. 1). Furthermore, an influence of the humidity on the results was observed. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - Interlaboratory Comparison KW - Functionalized graphene KW - Sample preparation PY - 2024 AN - OPUS4-60533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Ciornii, Dmitri A1 - Knigge, Xenia A1 - Hodoroaba, Vasile-Dan A1 - Bennet, F. A1 - Meirer, F. A1 - Duijndam, A. A1 - Thünemann, Andreas A1 - Drexel, R. A1 - Fadda, M. A1 - Sacco, A. A1 - Giovannozzi, A.M. A1 - Donskyi, I. A1 - Schusterbauer, R. A1 - Nickl, P. A1 - Reichardt, P. A1 - Altmann, Korinna T1 - Revealing surface functionalities of micro- and nanoplastic particles’ surface by means of XPS N2 - Over the last 20 years, many researchers, politicians, and citizens themselves have become increasingly aware of the growing plastic problem of our time. Inadequate recycling concepts, collection points, and careless dumping of plastic products in the environment lead to an accumulation of plastic. External weather influences can cause these to degrade and fractionate, so that today microplastics (1-1000 µm, ISO/TR 21960:2020) [1] of different polymer materials can be detected in all parts of the world. The precautionary principle applies to microplastics. The particles can break down further to form nanoplastics (<1 µm, ISO/TR 21960:2020) [1]. Whether microplastics or nanoplastics pose a toxicological hazard is being investigated in a variety of ways. Valid results are still pending, however, investigations into the frequency, transport, possible sinks and entry paths must be taken into account. This is why monitoring of microplastics is already required in the revision of the Drinking Water Framework Directive [2]. The same is still pending in the final version of the revision of the Waste Water Framework Directive this year, but is expected. Nanoplastics are particularly under discussion for having a toxic effect on humans and animals, as these particles are small enough to be absorbed by cells. For targeted toxicological studies, it is important to have test and reference materials that resemble the particles found in the environment. To mimic environmental samples, these materials should also have an irregular shape and show aging at the surface, which can be detected with XPS or SEM/EDS. BAM in collaboration with the EMPIR project "PlasticTrace" works on a reference material candidate of nano-sized polypropylene (nano-PP) [3]. The nano-PP vials were tested for homogeneity with PTA and further characterized with bulk and surface-sensitive techniques. An SEM image and a corresponding XPS spectrum are presented in Figure 1. Raman measurements as well as XPS indicate an aged surface. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - Surface chemistry KW - Micro- and nanoplastics KW - X-ray Photoelectron Spectroscopy KW - MNP production technique PY - 2024 AN - OPUS4-60535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stockmann, Jörg M. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Weimann, T. A1 - Bütefisch, S. T1 - A new XPS test material for more reliable surface analysis of microstructures N2 - Small-area XPS analysis is one of the most popular and powerful methods for analysing the surface of features in the micro-range. When measuring microstructures, the ques-tion arises whether the measuring point is really located at the point intended to be ana-lysed. Information in a measured spectrum might originate within the field of view (FoV) on the surface of the sample, from outside the FoV, or even from inherent contamination. To ensure that small structures can be measured correctly regardless of user and instru-ment, certain instrument and sample settings must be known and selected correctly: beam and aperture size as well as the aperture settings and the approximate dimensions of the structure to be analysed. This is the only way to ensure that the information in the spectrum originates only from the FoV on the analysed structure. To test the performance of the XPS instruments, a dedicated test material was developed that consists of a gold surface on which 8 circles and 8 squares of chrome are incorpo-rated using a masking process, so that the Au substrate and the Cr structure surfaces are in the same surface plane. In order to be able to test as many as possible instruments from different manufacturers, the structures have been designed with a size ranging from 300 µm down to 7 µm. The layout of the test material has been optimised in regard of the handling. The structures are arranged along lines instead of a circumference, marking arrows around the smaller structures (≤50 µm) are added, and the lithography mask is optimised regarding edge and diffraction effects. Furthermore, the manufacturing process was changed from electron-beam deposition to mask lithography due to costs reasons. The structures on the test material were measured with a metrological SEM to determine their accurate dimensions and check the repeatability of the manufacturing process. XPS investigations with a Kratos AXIS Ultra DLD and an ULVAC-Phi Quantes demonstrates the suitability of this new test material for measuring the analysed area. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - Small-area XPS KW - Test material KW - Field of view KW - Imaging PY - 2024 AN - OPUS4-60539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Favre, G. T1 - How to expand the use of your test method? Validation is key towards standardisation N2 - Standardised methods need validation. The main validation parameters like trueness, repeatability and intermediate precision and reproducibility are presented. Furthermore, different methods for the validation are disussed: (certified) reference materials, representative testing materials and interlaboratory comparisons. At last, the need of proficiency testing is stressed. T2 - Materials Week 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Validation KW - Reproducibility crisis KW - Metrological traceability KW - Measurement uncertainty PY - 2024 AN - OPUS4-60536 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Habibimarkani, Heydar A1 - Abram, Sarah Luise A1 - Prinz, Carsten A1 - Hodoroaba, Vasile-Dan T1 - Comparative chemical analysis of Ni-Fe oxide nanoparticles N2 - Ni-Fe oxide nanoparticles have gained a lot of interest because of their high activity in the oxygen evolution reaction (OER) which is crucial for water splitting. [1] Although there have been great efforts in the last years, the understanding of the synergistic effect between Fe and Ni is still under discussion. Therefore, we prepared different Ni-Fe oxide nanoparticles with different compositions from pure iron oxide to pure nickel oxide adapting a known procedure. [2,3] Size and morphology of the nanoparticles depend on the composition which was shown with Transmission Electron Microscopy (TEM). The compositions of the nanoparticles were measured with a comparative approach using X-ray Photoelectron Spectroscopy (XPS), Hard X-ray Photoelectron Spectroscopy (HAXPES), and Energy Dispersive X-Ray Spectroscopy (EDS) coupled with the TEM providing detailed chemical information of the nanoparticles in different sample regions. EDS reveals that the different sample regions are dominated by one of the components, Fe or Ni, but a slight mixing between the components can be found (see Figure 1), which was confirmed with X-ray Diffraction (XRD). XPS indicates the enrichment of Fe at the sample surface, while HAXPES and EDS data agree on the stoichiometry of the bulk. High-resolution XPS and HAXPES exhibit some differences in the valence states of Fe and Ni, whereas Ni seems to be easier to reduce than Fe. Further investigations combining these different techniques and additionally Secondary Ion Mass Spectrometry (ToF-SIMS) are ongoing by using in situ approaches and coupling cyclic voltammetry to the analytical techniques. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - Oxygen evolution reaction KW - Transmission Electron Microscopy KW - (Hard) X-ray Photoelectron Spectroscopy KW - Synergistic effects PY - 2024 AN - OPUS4-60534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Standardisation needs for regulatory testing of graphene and related 2D materials. phy-chem properties N2 - The main properties and main methods which are needed for the physico-chemical characterisation of graphene related 2D materials are discussed. As expample for standardization, protocols for the measurement of the chemical composition with XPS are discussed. The results of an interlaboratory comparisons led to new recommendations for the reliable measurments protocols. T2 - Materials Week 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Standardisation KW - Functionalized graphene KW - Interlaboratory comparison KW - Endpoints PY - 2024 AN - OPUS4-60537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - How to perform reliable xps-measurements? N2 - Reliable measurements are a great challenge in X-ray photoelectron spectroscopy. It will be shown, how to check the performance and calibration of the instrument, the charge compensation, quantification, fitting, and depth profiling. T2 - Course for PhD students at SFB 1073 CY - Göttingen, Germany DA - 23.02.2024 KW - X-ray photoelectron spectroscopy KW - Reproducibility crisis KW - Reliability PY - 2024 AN - OPUS4-59590 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Stockmann, Jörg Manfred A1 - Knigge, Xenia A1 - Chemello, Giovanni A1 - Hodoroaba, Vasile-Dan A1 - Resch-Genger, Ute A1 - Madkour, S. A1 - Schönhals, Andreas A1 - Reed, B. A1 - Clifford, C. A1 - Shard, A. T1 - (hard) x ray photoelectron spectroscopy as tool in nano-analytics N2 - Selected samples are used to show, that photoelectron spectroscopy is an important tool for measuring nano-objects, especially for determing the chemical composition and structure on the nanosacle. XPS with different energies offers new possibilities in depth-profiling. T2 - SFB 1073 Colloquium CY - Göttingen, Germany DA - 22.02.2024 KW - X-ray photoelectron spectroscopy KW - Core-shell nanoparticle KW - Graphene related 2D materials PY - 2024 AN - OPUS4-59589 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voss, Heike A1 - Knigge, Xenia A1 - Knapic, D. A1 - Weise, Matthias A1 - Sahre, Mario A1 - Radnik, Jörg A1 - Müller, Kai A1 - Wasmuth, Karsten A1 - Baumgartner, W. A1 - Krüger, Jörg A1 - Heitz, J. A1 - Hassel, A. W. A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Picosecond laser processing of hierarchical micro-nanostructures on Ti-alloy upon pre- and post-anodization N2 - Recent publications indicate that the order of electrochemical anodization (before or after the laser-processing step) plays an important role for the response of boneforming osteoblasts – an effect that can be utilized for improving permanent dental- or removable bone-implants. For exploring these different surface functionalities, multi-method chemical and structural characterizations were performed for two different characteristic micro-spikes covered by nanometric laserinduced periodic surface structures (LIPSS) on Ti-6Al-4V upon irradiation with nearinfrared ps-laser pulses (1030 nm wavelength, ~1 ps pulse duration, 66 & 80 kHz pulse repetition rate) at two distinct sets of laser fluence and beam scanning parameters. This involves morphological and topographical investigations by scanning electron microscopy (SEM) and white light interference microscopy (WLIM), near-surface chemical analysis by X-ray photoelectron spectroscopy (XPS) and hard X-ray photoelectron spectroscopy (HAXPES), as well as structural material examination via X-ray diffraction (XRD) measurements. The results allow to qualify the laser ablation depth, assess the spike geometry and surface roughness parameters, and provide detailed insights into the near-surface oxidation that may cause the different cell growth behavior for pre- or post-anodized medical implants. T2 - E-MRS Spring Meeting 2023 CY - Strasbourg, France DA - 29.05.2023 KW - Hard X-ray photoelectron spectroscopy (HAXPES) KW - Laser-induced periodic surface structures (LIPSS) KW - Ti6Al4V alloy KW - Hierarchical micro-nanostructures KW - Ultrashort laser processing PY - 2023 AN - OPUS4-60344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Lippitz, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Schmid, Thomas A1 - Heinrich, Hans-Joachim A1 - Recknagel, Sebastian A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Zirconium permanent modifiers for graphite furnaces used in absorption spectrometry: understanding their structure and mechanism of action N2 - The mechanism of action of zirconium permanent modifiers on graphite surfaces was investigated in order to understand its influence on the analytical signal in atomic and molecular absorption spectrometry (AAS/MAS). For this, the molecule formation of CaF was studied, which is used for the indirect analytical determination of fluorine in high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). The kinetics of this reaction was established by monitoring its molecular spectrum at different atomisation temperatures. An Arrhenius plot showed a pseudo-first order reaction with respect to fluorine (n = 1). An intermediate state was isolated, and its structure was elucidated by spectroscopic methods: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEMEDX), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES and EXAFS), and Raman microspectroscopy. We propose here a mechanism, where ZrO2 acts as a heterogeneous catalyst: after a pyrolytic step, an intermediate state of ZrO(OCaF) is activated, and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. No evidence of the formation of zirconium carbide was found. Consequently, as the CaF formation is catalysed by a heterogeneous catalyst, surface modifications with ZrO2 nanoparticles and ZrO xerogels were investigated in order to increase the surface area. Their influence was evaluated in the molecule formation of CaF, CaCl, CaBr, and CaI. Graphite furnace modification with zirconium oxide nanoparticles proves to be the best choice for fluorine analysis with a signal enhancement of more than eleven times with respect a non-coated graphite furnace. However, the influence of zirconium modifications in the analytical signals of Cl, and I is lower than the F signals or even negative in case of the Br. Understanding zirconium modifiers as heterogeneous catalysts offers a new perspective to AAS and MAS, and reveals the potential of surface analytical methods for development of improved permanent modifiers and graphite furnace coatings. KW - Zirconium KW - HR-CS-MAS KW - Graphite furnace KW - Nanoparticles KW - Xerogel KW - Calcium monofluoride KW - Absorption spectrometry PY - 2018 UR - https://pubs.rsc.org/en/content/articlelanding/2018/ja/c8ja00190a DO - https://doi.org/10.1039/C8JA00190A SN - 0267-9477 VL - 33 IS - 12 SP - 2034 EP - 2042 PB - Royal Society of Chemistry AN - OPUS4-46775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Lee, Jun-Seob A1 - Radnik, Jörg T1 - Electrochemical behavior of UNS N08031 in Green-Death-solution N2 - The electrochemical behavior of UNS N08031 was investigated as a function of electrode potential in Green-Death solution at 40 °C. The UNS N08031 surface is in a stable passive state during cyclic potentiodynamic polarization without an initiation and/or propagation of localized corrosion. In potentiostatic polarization of UNS N08031 for 3600 s, passive current density increases with an increase in the passivation potential from 0.7 to 1.0 VSSE (silver/silver chloride reference electrode in saturated potassium chloride) Electrochemical impedance spectroscopy (EIS) and Mott-Schottky (M-S) analysis showed that a more defective n-type semiconductive passive film forms as the potential increases. X-ray photoelectron spectroscopy (XPS) revealed that passive film consists of mainly chromium and minor iron and nickel oxides. The mechanism of the defective passive film formation is discussed. The increase of the applied potential is considered to be a reason for the change in passive film stability. T2 - NACE International Annual Corrosion Conference CY - Phoenix, AZ, USA DA - 15.04.2018 KW - Steel KW - Passive film KW - X-ray photoelectron spectroscopy PY - 2018 AN - OPUS4-44920 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - An, Q. A1 - Bäßler, Ralph A1 - Hertwig, Andreas A1 - Rehfeldt, Rainer A1 - Hidde, Gundula T1 - Investigation of mechanical stress and B10 exposure on FKM polymer N2 - Biofuels, particularly biodiesel, have gained significant attention as an alternative to traditional fossil fuels in recent years. Unlike diesel, which contains hundreds of compounds, biodiesel only contains a few compounds in the C16-C18 carbon chain. However, the use of biodiesel in automobile and transportation applications can result in problems of degradation or even damage in materials. Among the commonly used polymer materials, fluorocarbon (FKM) shows excellent performance and high stability and compatibility towards oil, diesel, ethanol, and other chemicals. FKM is a family of fluorocarbon-based fluoroelastomer materials, which provide excellent high-temperature and chemical stability compared to other elastomers. As a result, FKM is widely used in chemical processes such as petroleum refining, where it is used for sealings, pumps, and other components. T2 - TMS 2024 153rd Annual Meeting & Exhibition Supplemental Proceedings CY - Orlando, Florida, USA DA - 03.03.2024 KW - B10 exposure KW - FKM polymer PY - 2024 AN - OPUS4-59636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Q. A1 - Bäßler, Ralph A1 - Hertwig, Andreas A1 - Rehfeldt, Rainer A1 - Hidde, Gundula A1 - Otremba, Frank T1 - Investigation of Mechanical Stress and B10 Exposure on FKM Polymer N2 - Mechanical stress often accelerates the failure of polymer materials. The aim of this research is to study the interaction between the sealing material FKM and biofuels B10 (heating oil with 10% biodiesel). The mechanical stress test was carried out in a special apparatus. Both mechanical and non-mechanical stress tests were conducted on specimens at 20, 40, and 70 °C for 28 days to document changes in mass, volume, and tensile properties. Both increasing temperature and mechanical stress have a significant effect on the tensile strength of the FKM polymer when exposed to B10. The combination of increasing temperature and mechanical stress induced rupture within 2 h. It was also established that FKM polymer with pre-exposure in B10 survived longer during mechanical stress compared to specimens exposed only to air. With the support of infrared (IR) spectroscopy, we were able to confirm the penetration of B10 into the FKM polymer. T2 - TMS 2024 Annual Meeting & Exhibition Teilnahme mit Präsentation CY - Orlando-Florida / USA DA - 03.03.2024 KW - Biofuels KW - Sealing materials KW - Mechanical stress KW - Change in tensile properties PY - 2024 DO - https://doi.org/10.1007/978-3-031-50349-8_108 SP - 1253 EP - 1261 PB - Springer CY - Orlando-Florida / USA AN - OPUS4-59638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lee, Jun-Seob A1 - Radnik, Jörg A1 - Bäßler, Ralph T1 - Passivity of alloy 31 in green-death solution N2 - The passivation behavior of alloy 31 was investigated as a function of passivation potential in a green-death solution at 40 °C. The alloy 31 surface is in a stable passive state during cyclic potentiodynamic polarization. In potentiostatic polarization of alloy 31, passive current density increases with an increase in the passivation potential. Electrochemical impedance spectroscopy (EIS) and Mott–Schottky (M–S) analysis showed that a more defective n-type semiconductive passive film forms as the potential increases. X-ray photoelectron spectroscopy (XPS) revealed that passive film consists of mainly chromium and minor iron and nickel oxides. The increase of the applied potential is considered to be a reason for the change in passive film stability. KW - Passive film KW - Steel KW - Alloy 31 KW - X-ray photoelectron spectroscopy PY - 2018 DO - https://doi.org/10.1002/maco.201709996 SN - 0947-5117 SN - 1521-4176 VL - 69 IS - 9 SP - 1218 EP - 1226 PB - Wiley-VCH CY - Weinheim AN - OPUS4-45938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Ciornii, Dmitri A1 - Hodoroaba, Vasile-Dan A1 - Benismail, Nizar A1 - Altmann, Korinna T1 - Project 2: Interlaboratory Comparison on detection and quantitative assessment of microplastics by use of spectroscopic and thermo-analytical methods N2 - Validated and standardized methods in microplastic analysis are indispensable for robust monitoring and regulation. Alongside also reference materials are urgently needed. An interlaboratory comparison (ILC) offers a powerful tool to address both these challenges. The present study aimed to compare the precision and accuracy of various methods for the detection and quantification of microplastic in a water-soluble matrix. Additionally, it evaluated the suitability of the test materials (containing environmentally relevant plastic polymers) to serve as reference materials for the microplastic analysis. In this ILC several most used thermo-analytical and spectroscopic methods have been addressed: Pyrolysis-Gas Chromatography Mass Spectrometry (Py-GC/MS), Thermal Extraction-Desorption Gas Chromatography Mass Spectrometry (TED-GC/MS), micro-Fourier Transform Infrared Spectroscopy (µ-FTIR), and micro-Raman Spectroscopy and Laser Direct Infrared Spectroscopy (LDIR). Microplastic powders of polyethylene (PE) and polyethylene terephthalate (PET) were used to assess suitability of the test materials (microplastic tablets) for method validation and use in the ILCs. The participants were guided with a SOP how to dissolve the test samples and, depending on their selected method, either quantify the number of particles (by the spectroscopic methods) or determine the mass fraction of microplastic particles per sample (by the thermo-analytical methods). KW - ILC KW - Microplastic KW - FTIR KW - Raman KW - TED-GC/MS KW - Py-GC/MS PY - 2024 SP - 1 EP - 16 AN - OPUS4-60612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -