TY - JOUR A1 - Yesilcicek, Yasemin A1 - Haas, S. A1 - Suárez Ocano, Patricia A1 - Zaiser, E. A1 - Hesse, René A1 - Többens, D. M. A1 - Glatzel, U. A1 - Manzoni, Anna Maria T1 - Controlling Lattice Misfit and Creep Rate Through the γ' Cube Shapes in the Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex Alloy with Hf and W Additions N2 - Trace elements play an important role in the fine-tuning of complex material properties. This study focuses on the correlation of microstructure, lattice misfit and creep properties. The compositionally complex alloy Al10Co25Cr8Fe15Ni36Ti6 (in at. %) was tuned with high melting trace elements Hf and W. The microstructure consists of a γ matrix, γ' precipitates and the Heusler phase and it is accompanied by good mechanical properties for high temperature applications. The addition of 0.5 at.% Hf to the Al10Co25Cr8Fe15Ni36Ti6 alloy resulted in more sharp-edged cubic γ′ precipitates and an increase in the Heusler phase amount. The addition of 1 at.% W led to more rounded γ′ precipitates and the dissolution of the Heusler phase. The shapes of the γ' precipitates of the alloys Al9.25Co25Cr8Fe15Ni36Ti6Hf0.25W0.5 and Al9.25Co25Cr8Fe15Ni36Ti6Hf0.5W0.25, that are the alloys of interest in this paper, create a transition from the well-rounded precipitates in the alloy with 1% W containing alloy to the sharp angular particles in the alloy with 0.5% Hf. While the lattice misfit has a direct correlation to the γ' precipitates shape, the creep rate is also related to the amount of the Heusler phase. The lattice misfit increases with decreasing corner radius of the γ' precipitates. So does the creep rate, but it also increases with the amount of Heusler phase. The microstructures were investigated by SEM and TEM, the lattice misfit was calculated from the lattice parameters obtained by synchrotron radiation measurements. KW - High entropy alloy KW - Lattice misfit KW - Creep KW - Transmission electron microscopy KW - X-ray diffraction PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565655 DO - https://doi.org/10.1007/s44210-022-00009-1 SP - 1 EP - 9 PB - Springer AN - OPUS4-56565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wolf, M. E. A1 - Vickery, W. M. A1 - Swift-Ramirez, W. A1 - Arnold, A. M. A1 - Orlando, J. D. A1 - Schmidt, S. J. A1 - Liu, Y. A1 - Er, Jasmin A1 - Schusterbauer, Robert A1 - Ahmed, R. A1 - Nickl, Philip A1 - Radnik, Jörg A1 - Donskyi, Ievgen A1 - Sydlik, S. A. T1 - The Mitsunobu reaction for the gentle covalent attachment of biomolecules to graphene oxide N2 - Graphene oxide (GO) has emerged as a promising biomaterial as it is easily and cheaply synthesized, strong, cytocompatible, osteoinductive, and has a well-characterized aqueous degradation pathway. It is also a great substrate for functionalization with biomolecules such as proteins, peptides, and small molecules that can enhance or add bioactivity. Covalent chemical linkages as opposed to typical noncovalent association methods are preferable so that the biomolecules do not quickly diffuse away or face replacement by other proteins, which is critical in long time scale applications like bone regeneration. However, covalent chemistry tends to carry a drawback of harsh reaction conditions that can damage the structure, conformation, and therefore function of a delicate biomolecule like a protein. Here, the Mitsunobu reaction is introduced as a novel method of covalently attaching proteins to graphene oxide. It features gentle reaction conditions and has the added benefit of utilizing the plentiful basal plane alcohol functionalities on graphene oxide, allowing for high yield protein functionalization. The amino acid Glycine (G), the protein bovine serum albumin (BSA), and the small molecule SVAK-12 are utilized to create the three Mitsunobu Graphene (MG) materials G-MG, BSA-MG, and SVAK-MG that demonstrate the wide applicability of this functionalization method. KW - Graphene oxide KW - Mitsunobu reaction KW - Covalent attachment KW - Bovine serum albumin KW - Macrophage polarization KW - Osteogenesis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630483 DO - https://doi.org/10.1016/j.carbon.2025.120221 VL - 238 SP - 1 EP - 15 PB - Elsevier Ltd. AN - OPUS4-63048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiesner, Yosri A1 - Altmann, Korinna A1 - Braun, U. T1 - Determination of Microplastic Mass Content by Thermal Extraction Desorption Gas Chromatography– Mass Spectrometry N2 - The scientific and practical challenge of detecting microplastics (MPs) in the environment in a targeted and rapid manner is solved by innovative coupling of thermogravimetric analysis with mass spectrometric methods. Fast identification and quantitative determination of most thermoplastic polymers and elastomers is possible by using thermal extraction Desorption gas chromatography–mass spectrometry (TED-GC–MS). KW - Microplastics KW - Mikroplastik KW - TED-GC/MS KW - Microplastics analytic KW - Mikroplastik Massegehalt PY - 2021 VL - 17 IS - 3 SP - 2 EP - 7 PB - MultiMedia (UK) LLC CY - Cranbury AN - OPUS4-52570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Usmani, Shirin M. A1 - Plarre, Rüdiger A1 - Hübert, Thomas A1 - Kemnitz, E. ED - Richter, K. ED - Van de Kulien, J.-W. T1 - Termite resistance of pine wood treated with nano metal fluorides N2 - Fluorides are well-known as wood preservatives. One of the limitations of fluoride-based wood preservatives is their high leachability. Alternative to current fluoride salts such as NaF used in wood protection are low water-soluble fluorides. However, impregnation of low water-soluble fluorides into wood poses a challenge. To address this challenge, low water-soluble fluorides like calcium fluoride (CaF2) and magnesium fluoride (MgF2) were synthesized as nanoparticles via the fluorolytic sol−gel synthesis and then impregnated into wood specimens. In this study, the toxicity of nano metal fluorides was assessed by termite mortality, mass loss and visual analysis of treated specimens after eight weeks of exposure to termites, Coptotermes formosanus. Nano metal fluorides with sol concentrations of 0.5 M and higher were found to be effective against termites resulting in 100% termite mortality and significantly inhibited termite feeding. Among the formulations tested, the least damage was found for specimens treated with combinations of CaF2 and MgF2 with an average mass loss less than 1% and visual rating of “1”. These results demonstrate the efficacy of low water-soluble nano metal fluorides to protect wood from termite attack. KW - Holzschutzmittel KW - Nanoparticles KW - Fluorides KW - Termites PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514325 DO - https://doi.org/10.1007/s00107-020-01522-z VL - 78 SP - 493 EP - 499 PB - Springer CY - Berlin AN - OPUS4-51432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terborg, R. A1 - Kim, K. J. A1 - Hodoroaba, Vasile-Dan T1 - Determination of Thin Film Thickness and Composition using Energy Dispersive EPMA N2 - The thickness of thin films can be measured by various methods, e.g., profilometry, ellipsometry, atomic force 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. KW - Thin films KW - Elemental composition KW - Film thickness KW - EPMA (Electron Probe Microanalysis) PY - 2022 DO - https://doi.org/10.1017/S143192762200318X VL - 28 IS - Suppl. 1 SP - 672 EP - 673 PB - Cambridge University Press AN - OPUS4-55437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sänger, Johanna Christiane A1 - Pauw, Brian Richard A1 - Sturm, Heinz A1 - Günster, Jens T1 - First time additively manufactured advanced ceramics by using two-photon polymerization for powder processing N2 - Methods and materials are presented here, which enable the manufacturing of fine structures using a 3D-printing method known as two-photon polymerization (2PP). As traditional photolithography methods for structuring ceramic slurries do not function with 2PP, due to light scattering on ceramic particles, a novel water-based photoresist with high ceramic loading of extremely well dispersed ceramic nano particles was developed. This photoresist is basically a ceramic slurry containing a photocurable agent and a photoinitiator to be crosslinkable with the 780 nm wavelength femtosecond laser light source of the 2PP machine. It is demonstrated that it is possible to gain a highly transparent and low viscous slurry suitable for 2PP processing. This work shows the development of the slurry, first printing results and the post-printing processes required to form three dimensional ceramic microstructures consisting of alumina toughened zirconia (ATZ). KW - 3D-printing KW - Two-photon polymerization KW - 2PP KW - Ceramic nano particles KW - Slurry KW - Alumina toughened zirconia KW - ATZ KW - Additive manufacturing KW - SchwarzP cells KW - Nano-ceramic-additive-manufacturing photoresin KW - NanoCAM PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517441 DO - https://doi.org/10.1016/j.oceram.2020.100040 VL - 4 SP - 100040 PB - Elsevier Ltd. AN - OPUS4-51744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Singh, Chandan A1 - Riedel, Soraya A1 - Konthur, Zoltán A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg A1 - Schenk, J. A. A1 - Schneider, Rudolf T1 - Functionalized Ti3C2Tx nanosheets based biosensor for point-of-care detection of SARS-CoV‑2 antigen N2 - MXenes are considered a promising class of two-dimensional materials with extraordinary physical and electrochemical properties. Distinguished features like high specific surface area and outstanding electrical conductivity make them suitable for electrochemical biosensing applications. Here, we report the development of a biosensor involving the functionalized MXene−titanium carbide nanosheets (Ti3C2Tx-NS) 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. Few-layered titanium carbide nanosheets (denoted as FL-Ti3C2Tx-NS) have been synthesized using a single-step etching and delamination method and characterized using optical and electron microscopy techniques revealing the suitability for immunosensing applications. Binding studies revealed the excellent affinity between the biosensor and the SARS-CoV-2 NP. Electrochemical detection of SARS-CoV-2 NP is performed using differential pulse voltammetry and read by a smartphone-based user interface. The proposed FL-Ti3C2Tx-NS based biosensor offers the detection of SARS-CoV-2 NP with a limit of detection of 0.91 nM in a wide detection range in spiked saliva samples. Additionally, there is no cross-reactivity in the presence of potential interferants like SARS-CoV-2 spike glycoprotein and bovine serum albumin. These findings demonstrate the potential of MXenes in developing a rapid and reliable tool for SARS-CoV-2 NP detection. While we report the biosensing of SARS-CoV-2 NP, our system also paves the way for the detection of other SARS-CoV-2 antigens like spike protein or other biomolecules based on antigen−antibody interactions. KW - Antigen testing KW - Few-layered titanium carbide nanosheets KW - SARS-CoV-2 nucleocapsid protein KW - Label-free detection KW - Electrochemical immunosensor PY - 2023 DO - https://doi.org/10.1021/acsaenm.2c00118 SN - 2771-9545 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. VL - 1 IS - 1 SP - 495 EP - 507 PB - American Chemical Society CY - Washington, DC AN - OPUS4-56931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwibbert, Karin A1 - de Eulate Pérez, Elisa García A1 - Wen, Keqing A1 - Voss, Heike A1 - Thiele, Dorothea A1 - Richter, Anja M. A1 - Bonse, Jörn T1 - Escherichia coli repellence via laser-induced periodic surface structures (LIPSS) on titanium: Critical role of biofilm-associated gene expression N2 - The inconsistency in the observed bacteria-repellent effects of laser-induced surface textures remains a subject of scientific debates. With E. coli TG1 as test strain, we performed biofilm formation assays on ultrashort pulse laser textured titanium. Samples covered with low spatial frequency LIPSS (LSFL) of periods around 750 nm or with high spatial frequency LIPSS (HSFL) featuring smaller periods around 100 nm were processed on polished samples. While LSFL significantly reduce the number of adhering bacteria compared to the polished reference, HSFL do not. Simultaneously, we concentrate our study on bacterial strategies employed for biofilm formation, that is the transcription of the biofilm-associated genes csgB, involved in primary adhesion to a surface, and wza, participating in biofilm maturation. Promoter regions of these genes were cloned into a promotor probe plasmid with the green fluorescent protein GFP+ as reporter and transferred into the test strain. As indicated by the fluorescence intensity of the reporter protein, among the bacteria colonizing LSFL-covered areas, a markedly higher proportion of cells transcribing csgB or wza were detected, compared to the bacterial populations colonizing the polished or HSFL-covered areas. To our knowledge, this is the first study indicating that the antifouling effect of LSFL topographies can be counteracted when bacteria activate biofilm-associated genes. KW - Laser-induced periodic surface structures (LIPSS) KW - Titanium KW - Biofilm KW - Antifouling KW - Gene expression KW - Fluorescence microscopy PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655572 DO - https://doi.org/10.1016/j.apsusc.2026.166363 SN - 0169-4332 VL - 730 SP - 1 EP - 9 PB - Elsevier B.V. AN - OPUS4-65557 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schusterbauer, Robert A1 - Schünemann, Pia A1 - Nickl, Philip A1 - Er, Jasmin A1 - Kämmer, Victoria A1 - Junge, Florian A1 - Fazzani, Salim A1 - Mrkwitschka, Paul A1 - Meermann, Björn A1 - Haag, Rainer A1 - Donskyi, Ievgen T1 - Bifunctional Reduced Graphene Oxide Derivatives for PFOA Adsorption N2 - Innovative materials are crucial for removing persistent pollutants per‐ and polyfluorinated alkyl substances (PFAS) from water. Here, a novel bifunctional reduced graphene oxide (TRGO) adsorbent is developed and characterized by advanced surface sensitive methods. Compared to pristine TRGO, the functionalized TRGO shows markedly improved PFAS removal efficiency and demonstrates strong potential for water purification applications. KW - Adsorber KW - PFAS KW - HR-CS-GFMAS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651238 DO - https://doi.org/10.1002/ceur.202500240 SN - 2751-4765 SP - 1 EP - 7 PB - Wiley VHC-Verlag AN - OPUS4-65123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmitt, M. A1 - Altmann, Korinna A1 - Fengler, Petra A1 - Gehde, M. T1 - Air-based polyethylene fragmentation with high yield to form microplastic particles as reference material candidates N2 - Microplastic particles with sizes between 1 to 1000 μm are widely distributed worldwide. Origin, transport pathways and fate are poorly known, as sampling, sample preparation and detection methods are major challenges. In addition, reference materials that mimic environmental particles are lacking. Most challenging is the yield of MP particle production and the need for resource-intensive grinding with liquid nitrogen. In this paper, a machine is designed to produce aged microplastic particles as reference material candidates with high yield. The machine is based on ultraviolet aging of a thin foil and mechanical fragmentation using clean air. An example of aging and fragmentation of high density polyethylene with additional physical and chemical characterization of shape, size, aging state by carbonyl index and density is presented. KW - Microplastics KW - Degradation of polyethylene KW - Air fragmentation KW - Microplastics reference material PY - 2023 DO - https://doi.org/10.1002/appl.202200121 SP - 1 EP - 18 PB - Wiley online library AN - OPUS4-57203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -