TY - JOUR A1 - Abusafia, A. A1 - Scheid, C. A1 - Meurer, Maren A1 - Altmann, Korinna A1 - Dittmer, U. A1 - Steinmetz, H. T1 - Microplastic sampling strategies in urban drainage systems for quantification of urban emissions based on transport pathways N2 - Tracking waterborne microplastic (MP) in urban areas is a challenging task because of the various sources and transport pathways involved. Since MP occurs in low concentrations in most wastewater and stormwater streams, large sample volumes need to be captured, prepared, and carefully analyzed. The recent research in urban areas focused mainly on MP emissions at wastewater treatment plants (WWTPs), as obvious entry points into receiving waters. However, important transport pathways under wet-weather conditions are yet not been investigated thoroughly. In addition, the lack of comprehensive and comparable sampling strategies complicated the attempts for a deeper understanding of occurrence and sources. The goal of this paper is to (i) introduce and describe sampling strategies for MP at different locations in a municipal catchment area under dry and wet-weather conditions, (ii) quantify MP emissions from the entire catchment and two other smaller ones within the bigger catchment, and (iii) compare the emissions under dry and wet-weather conditions. WWTP has a high removal rate of MP (>96%), with an estimated emission rate of 189 kg/a or 0.94 g/[population equivalents (PEQ · a)], and polyethylene (PE) as the most abundant MP. The specific dry-weather emissions at a subcatchment were ≈30 g/(PEQ · a) higher than in the influent of WWTP with 23 g/(PEQ · a). Specific wet-weather emissions from large sub-catchment with higher traffic and population densities were 1952 g/(ha · a) higher than the emissions from smaller catchment (796 g/[ha · a]) with less population and traffic. The results suggest that wet-weather transport pathways are likely responsible for 2–4 times more MP emissions into receiving waters compared to dry-weather ones due to tire abrasion entered from streets through gullies. However, more investigations of wet-weather MP need to be carried out considering additional catchment attributes and storm event characteristics. KW - Combined sewer system KW - Large volume samplers KW - Microplastic pollution KW - Separate sewer system KW - Stormwater retention tank PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568271 DO - https://doi.org/10.1002/appl.202200056 SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Accorsi, M. A1 - Tiemann, M. A1 - Wehrhan, L. A1 - Finn, Lauren M. A1 - Cruz, R. A1 - Rautenberg, Max A1 - Emmerling, Franziska A1 - Heberle, J. A1 - Keller, B. G. A1 - Rademann, J. T1 - Pentafluorophosphato-Phenylalanines: Amphiphilic Phosphotyrosine Mimetics Displaying Fluorine-Specific Protein Interactions N2 - Phosphotyrosine residues are essential functional switches in health and disease. Thus, phosphotyrosine biomimetics are crucial for the development of chemical tools and drug molecules. We report here the discovery and investigation of pentafluorophosphato amino acids as novel phosphotyrosine biomimetics. A mild acidic pentafluorination protocol was developed and two PF5-amino acids were prepared and employed in peptide synthesis. Their structures, reactivities, and fluorine-specific interactions were studied by NMR and IR spectroscopy, X-ray diffraction, and in bioactivity assays. The mono-anionic PF5 motif displayed an amphiphilic character binding to hydrophobic surfaces, to water molecules, and to protein-binding sites, exploiting charge and H−F-bonding interactions. The novel motifs bind 25- to 30-fold stronger to the phosphotyrosine binding site of the protein tyrosine phosphatase PTP1B than the best current biomimetics, as rationalized by computational methods, including molecular dynamics simulations. KW - Chemical Biology KW - Drug Development KW - Pentafluorophosphates KW - Phosphotyrosine Biomimetics KW - Protein Tyrosine Phosphatases PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549984 DO - https://doi.org/10.1002/anie.202203579 SN - 1433-7851 VL - 134 IS - 25 SP - 1 EP - 6 PB - Wiley-VCH GmbH AN - OPUS4-54998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Afantitis, A. A1 - Melagraki, G. A1 - Isigonis, P. A1 - Tsoumanis, A. A1 - Varsou, D. D. A1 - Valsami-Jones, E. A1 - Papadiamantis, A. A1 - Ellis, L.-J. A. A1 - Sarimveis, H. A1 - Doganis, P. A1 - Karatzas, P. A1 - Tsiros, P. A1 - Liampa, I. A1 - Lobaskin, V. A1 - Greco, D. A1 - Serra, A. A1 - Kinaret, P. A. S. A1 - Saarimäki, L. A. A1 - Grafström, R. A1 - Kohonen, P. A1 - Nymark, P. A1 - Willighagen, E. A1 - Puzyn, T. A1 - Rybinska-Fryca, A. A1 - Lyubartsev, A. A1 - Jensen, K. A. A1 - Brandenburg, J. G. A1 - Lofts, S. A1 - Svendsen, C. A1 - Harrison, S. A1 - Maier, D. A1 - Tamm, K. A1 - Jänes, J. A1 - Sikk, L. A1 - Dusinska, M. A1 - Longhin, E. A1 - Rundén-Pran, E. A1 - Mariussen, E. A1 - El Yamani, N. A1 - Unger, Wolfgang A1 - Radnik, Jörg A1 - Tropsha, A. A1 - Cohen, Y. A1 - Lesczynski, J. A1 - Hendren, C. O. A1 - Wiesner, M. A1 - Winkler, D. A1 - Suzuki, N. A1 - Yoon, T. H. A1 - Choi, J.-S. A1 - Sanabria, N. A1 - Gulumian, M. A1 - Lynch, I. T1 - NanoSolveIT Project: Driving nanoinformatics research to develop innovative and integrated tools for in silico nanosafety assessment N2 - Nanotechnology has enabled the discovery of a multitude of novel materials exhibiting unique physicochemical (PChem) properties compared to their bulk analogues. These properties have led to a rapidly increasing range of commercial applications; this, however, may come at a cost, if an association to long-term health and environmental risks is discovered or even just perceived. Many nanomaterials (NMs) have not yet had their potential adverse biological effects fully assessed, due to costs and time constraints associated with the experimental assessment, frequently involving animals. Here, the available NM libraries are analyzed for their suitability for integration with novel nanoinformatics approaches and for the development of NM specific Integrated Approaches to Testing and Assessment (IATA) for human and environmental risk assessment, all within the NanoSolveIT cloud-platform. These established and well-characterized NM libraries (e.g. NanoMILE, NanoSolutions, NANoREG, NanoFASE, caLIBRAte, NanoTEST and the Nanomaterial Registry (>2000 NMs)) contain physicochemical characterization data as well as data for several relevant biological endpoints, assessed in part using harmonized Organisation for Economic Co-operation and Development (OECD) methods and test guidelines. Integration of such extensive NM information sources with the latest nanoinformatics methods will allow NanoSolveIT to model the relationships between NM structure (morphology), properties and their adverse effects and to predict the effects of other NMs for which less data is available. The project specifically addresses the needs of regulatory agencies and industry to effectively and rapidly evaluate the exposure, NM hazard and risk from nanomaterials and nano-enabled products, enabling implementation of computational ‘safe-by-design’ approaches to facilitate NM commercialization. KW - Nanoinformatics KW - Hazard assessment KW - (Quantitative) Structure-Active Relationships KW - Safe-by-design KW - Predictive modelling PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505952 DO - https://doi.org/10.1016/j.csbj.2020.02.023 VL - 18 SP - 583 EP - 602 PB - Elsevier B.V. AN - OPUS4-50595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Agostini, G. A1 - Radnik, Jörg T1 - Spectroscopy in Catalysis N2 - Knowledge-based catalyst development is always an interaction between preparation, analysis and catalytic testing. Only if these three factors fit together can success be expected. For the analytic side of this triangle, spectroscopic methods play a crucial role. Whereas with diffraction, scattering and microscopy, decisive insights into the structure and morphology of the catalysts can be obtained, spectroscopy produces new knowledge about the chemical nature of the catalyst, e.g., its bonding and valence states. KW - Spectroscopy KW - Catalysis KW - Operando KW - In situ PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506507 DO - https://doi.org/10.3390/catal10040408 VL - 10 IS - 4 SP - 408 PB - MDPI CY - Basel AN - OPUS4-50650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ahmed, R. A1 - Vaishampayan, A. A1 - Cuellar-Camacho, J. L. A1 - Wight, D. J. A1 - Donskyi, Ievgen A1 - Unger, Wolfgang A1 - Grohmann, E. A1 - Haag, R. A1 - Wagner, O. T1 - Multivalent Bacteria Binding by Flexible Polycationic Microsheets Matching Their Surface Charge Density N2 - Aiming at the overall negative surface charge of bacteria, a new strategy of antibacterial agents based on large polymer-modified graphene oxide (GO) sheets is assessed. The presented flexible, polycationic Sheets match the size and charge density of the Escherichia coli surface charge density (2 × 1014 cm−2). These matching parameters create an unspecific but very strong bacteria adsorber by multivalent, electrostatic attraction. Their interaction with bacteria is visualized via atomic force and confocal microscopy and shows that they effectively bind and wrap around E. coli cells, and thereby immobilize them. The incubation of Gram-negative and -positive bacteria (E. coli and methicillin-resistant Staphylococcus aureus, MRSA) with these polycationic sheets leads to the inhibition of proliferation and a reduction of the colony forming bacteria over time. This new type of antibacterial agent acts in a different mode of Action than classical biocides and could potentially be employed in medicinal, technical, or agriculture applications. The presented microsheets and their unspecific binding of cell interfaces could further be employed as adsorber material for bacterial filtration or immobilization for imaging, analysis, or sensor technologies. KW - Surface charge KW - Bacteria KW - Graphene oxide KW - Escherichia coli KW - XPS PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509651 DO - https://doi.org/10.1002/admi.201902066 VL - 7 IS - 15 SP - 1902066 PB - WILEY-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-50965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Akbar, S. A1 - Hasanain, S.K. A1 - Ivashenko, O. A1 - Dutka, M.V. A1 - Akhtar, N. A1 - De Hosson, J.Th.M. A1 - Ali, Naveed A1 - Rudolf, P. T1 - Defect ferromagnetism in SnO2:Zn2+ hierarchical nanostructures: correlation between structural, electronic and magnetic properties N2 - We report on the ferromagnetism of Sn1-xZnxO2 (x < 0.1) hierarchical nanostructures with various morphologies synthesized by a solvothermal route. A room temperature ferromagnetic and paramagnetic response was observed for all compositions, with a maximum in ferromagnetism for x = 0.04. The ferromagnetic behaviour was found to correlate with the presence of zinc on substitutional Sn sites and with a low oxygen vacancy concentration in the samples. The morphology of the nanostructures varied with zinc concentration. The strongest ferromagnetic response was observed in nanostructures with well-formed shapes, having nanoneedles on their surfaces. These nanoneedles consist of (110) and (101) planes, which are understood to be important in stabilizing the ferromagnetic defects. At higher zinc concentration the nanostructures become eroded and agglomerated, a phenomenon accompanied with a strong decrease in their ferromagnetic response. The observed trends are explained in the light of recent computational studies that discuss the relative stability of ferromagnetic defects on various surfaces and the role of oxygen vacancies in degrading ferromagnetism via an increase in free electron concentration. KW - Ferromagnetism KW - Nanostructures KW - Magnetic properties PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473014 DO - https://doi.org/10.1039/c9ra00455f SN - 2046-2069 VL - 9 IS - 7 SP - 4082 EP - 4091 PB - Royal Society of Chemistry AN - OPUS4-47301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aliyah, K. A1 - Prehal, C. A1 - Diercks, J. S. A1 - Diklić, N. A1 - Xu, L. A1 - Ünsal, S. A1 - Appel, C. A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Guizar-Sicairos, M. A1 - Herranz, J. A1 - Gubler, L. A1 - Büchi, F. N. A1 - Eller, J. T1 - Quantification of PEFC Catalyst Layer Saturation via In Silico, Ex Situ, and In Situ Small-Angle X-ray Scattering N2 - The complex nature of liquid water saturation of polymer electrolyte fuel cell (PEFC) catalyst layers (CLs) greatly affects the device performance. To investigate this problem, we present a method to quantify the presence of liquid water in a PEFC CL using small-angle X-ray scattering (SAXS). This method leverages the differences in electron densities between the solid catalyst matrix and the liquid water filled pores of the CL under both dry and wet conditions. This approach is validated using ex situ wetting experiments, which aid the study of the transient saturation of a CL in a flow cell configuration in situ. The azimuthally integrated scattering data are fitted using 3D morphology models of the CL under dry conditions. Different wetting scenarios are realized in silico, and the corresponding SAXS data are numerically simulated by a direct 3D Fourier transformation. The simulated SAXS profiles of the different wetting scenarios are used to interpret the measured SAXS data which allows the derivation of the most probable wetting mechanism within a flow cell electrode. KW - Polymer electrolyte fuel cell KW - Water management KW - Catalyst layer KW - Representative morphology modeling KW - Small-angle X-ray scattering KW - MOUSE KW - SAXS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575973 DO - https://doi.org/10.1021/acsami.3c00420 SN - 1944-8244 VL - 15 IS - 22 SP - 26538 EP - 26553 PB - ACS Publications AN - OPUS4-57597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Almalla, A. A1 - Hertwig, Andreas A1 - Fischer, Daniel A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia T1 - Development of layer-by-layer assembled thin coatings on aluminium alloy AA2024-T3 for high resolution studies of local corrosion processes N2 - The aim of this study is to develop nanometer-thin epoxy-based films on aluminium alloy AA2024-T3 as a model coating system for high resolution corrosion studies. Spin coating was used for the layer-by-layer (LbL) deposition of poly-(ethylenimine) (PEI) and poly([o-cresyl glycidyl ether]-co-formaldehyde) (CNER) bilayers. The film chemistry and the cross-linking process were characterized by means of Fourier-transform infrared spectroscopy (FTIR). Ellipsometric data confirmed the linear increase of film thickness. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) results indicate the improvement of the film barrier properties with increasing film thickness. Mapping of the topography and the volta potential was performed by means of scanning Kelvin probe force microscopy (SKPFM). The results indicate the presence of a homogeneous film structure, while the intermetallic phases can still be identified below the coating. The SKPFM Analysis confirmed that the model films are suitable for investigation of corrosion processes at the coating/metal interface. KW - Spectroscopy KW - Coatings KW - Electrochemistry KW - Microscopy KW - Resins PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514627 DO - https://doi.org/10.1002/app.49826 SN - 0021-8995 VL - 137 IS - 48 SP - e49826-1 EP - e49826-9 PB - Wiley CY - New York, NY AN - OPUS4-51462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Almalla, A. A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia T1 - In Situ Atomic Force Microscopy Analysis of the Corrosion Processes at the Buried Interface of an Epoxy-like Model Organic Film and AA2024-T3 Aluminum Alloy N2 - The application of characterization methods with high spatial resolution to the analysis of buried coating/metal interfaces requires the design and use of model systems. Herein, an epoxy-like thin film is used as a model coating resembling the epoxy-based coatings and adhesives widely used in technical applications. Spin coating is used for the deposition of a 30 nm-thin bilayer (BL) composed of poly-(ethylenimine) (PEI) and poly[(o-cresyl glycidyl ether)-co-formaldehyde] (CNER). Fourier-transform infrared spectroscopy (FTIR) results confirm that the exposure of coated AA2024-T3 (AA) samples to the corrosive electrolyte solution does not cause the degradation of the polymer layer. In situ atomic force microscopy (AFM) studies are performed to monitor local corrosion processes at the buried interface of the epoxy-like film and the AA2024-T3 aluminum alloy surface in an aqueous electrolyte solution. Hydrogen evolution due to the reduction of water as the cathodic corrosion reaction leads to local blister formation. Based on the results of the complementary energy-dispersive X-ray spectroscopy (EDX) analysis performed at the same region of interest, most of the hydrogen evolved originates at the vicinity of Mg-containing intermetallic particles. KW - Scanning Kelvin probe force microscopy KW - Aluminum alloys KW - Buried interfaces KW - In situ atomic force microscopy KW - Local corrosion PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546932 DO - https://doi.org/10.1002/adem.202101342 SN - 1438-1656 SP - 1 EP - 9 PB - Wiley VHC-Verlag AN - OPUS4-54693 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altmann, Korinna A1 - Goedecke, Caroline A1 - Bannick, C.-G. A1 - Abusafia, A. A1 - Scheid, C. A1 - Steinmetz, H. A1 - Paul, Andrea A1 - Beleites, C. A1 - Braun, U. T1 - Identification of microplastic pathways within a typical European urban wastewater system N2 - In recent years, thermoextraction/desorption-gas chromatography/mass spectrometry (TED-GC/MS) has been developed as a rapid detection method for the determination of microplastics (MP) mass contents in numerous environmentally relevant matrices and, in particular, for the measurement of polymers in water samples without time-consuming sample preparation. The TED-GC/MS method was applied to investigate a typical European municipal wastewater system for possible MP masses. Such investigations are important in view of the recent revision of the Urban Wastewater Treatment Directive. Four different representative sampling sites were selected: greywater (domestic wastewater without toilet), combined sewer, and influent and effluent of a wastewater treatment plant (WWTP). All samples were collected by fractional filtration. Filtration was carried out over mesh sizes of 500, 100, 50, and in some cases, 5 µm. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) were detected in all samples, with the PE fraction dominating in all cases. Styrene-butadiene rubber which serves as an indication of tire abrasion, was only found in the influent of the WWTP. The highest MP mass contents were found in the combined sewer, so MP can become a source of pollution during heavy rain events when the capacity limits of the effluent are reached, and the polluted effluent is released uncontrolled into the environment. Based on the studies, MP retention from the WWTP could be estimated to be approximately 96%. Few trends in polymer type or mass contents were detected within the different fractions of the samples or when comparing samples to each other. KW - Microplastics KW - Microplastic analysis KW - TED-GC/MS KW - Microplastic pathways KW - Mass contents PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568289 DO - https://doi.org/doi.org/10.1002/appl.202200078 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -