TY - JOUR A1 - Stühler, Merlin R. A1 - Makki, Hesam A1 - Silbernagl, Dorothee A1 - Dimde, Mathias A1 - Ludwig, Kai A1 - Tegner, Bengt E. A1 - Greve, Christopher A1 - Rausch, Konstantin A1 - Herzig, Eva M. A1 - Köhler, Anna A1 - Plajer, Alex J. T1 - Flexibility and Dynamicity Enhances and Controls Supramolecular Self-Assembly of Zinc(II) Metallogels N2 - Supramolecular self-assembly of stacked architectures is typically achieved through hydrogen bonding or π–π interactions between monomers constructed from stable and inert bonds. In contrast, coordinative interactions of early metals promise distinct self-assembly behaviour due to more flexible bonding geometries and a wider range of stabilities and exchange kinetics. In this report we demonstrate that tailoring the flexible coordination sphere of Zinc(II) complexes via subtle ligand modification promotes not only one but also three-dimensional self-assembly both thermodynamically and kinetically into higher-order fibrous morphologies, the latter being elucidated by electron tomography. As a result, coordination chemistry can be translated into both nanoscopic (fibre stiffness) and macroscopic (thermal gel stability) material properties. Utilizing dynamicity enables gelation via subcomponent self-assembly, constructing the supramolecular polymer network simultaneously with the monomer. Furthermore, coordinative dis- and reassembly via metal-ligand exchange reactions involving the first and second coordination spheres allows for control over gelation and emission of the system. Our report links concepts in supramolecular self-assembly and coordination chemistry by leveraging the unique bonding interactions that cannot be achieved for traditional monomers, promising applications in stimuli-responsive optoelectronics. KW - Nanomaterial KW - AFM KW - Organometallic KW - Gel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634221 DO - https://doi.org/10.1002/adfm.202507793 SN - 1616-301X SP - 1 EP - 10 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-63422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stinville, J.C. A1 - Charpagne, M.A. A1 - Maaß, Robert A1 - Proudhon, H. A1 - Ludwig, W. A1 - Callahan, P.G. A1 - Wang, F. A1 - Beyerlein, I.J. A1 - Echlin, M.P. A1 - Pollock, T.M. T1 - Insights into Plastic Localization by Crystallographic Slip from Emerging Experimental and Numerical Approaches N2 - Advanced experimental and numerical approaches are being developed to capture the localization of plasticity at the nanometer scale as a function of the multiscale and heterogeneous microstructure present in metallic materials. These innovative approaches promise new avenues to understand microstructural effects on mechanical properties, accelerate alloy design, and enable more accurate mechanical property prediction. This article provides an overview of emerging approaches with a focus on the localization of plasticity by crystallographic slip. New insights into the mechanisms and mechanics of strain localization are addressed. The consequences of the localization of plasticity by deformation slip for mechanical properties of metallic materials are also detailed. KW - Slip localization KW - Metallic materials KW - Experimental and numerical techniques KW - Mechanical properties KW - Plasticity PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578398 DO - https://doi.org/10.1146/annurev-matsci-080921-102621 SN - 1531-7331 VL - 53 SP - 275 EP - 317 AN - OPUS4-57839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Smekhova, A. A1 - Kuzmin, A. A1 - Siemensmeyer, K. A1 - Luo, C. A1 - Taylor, J. A1 - Thakur, S. A1 - Radu, F. A1 - Weschke, E. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Xiao, B. A1 - Savan, A. A1 - Yusenko, Kirill A1 - Ludwig, A. T1 - Local structure and magnetic properties of a nanocrystalline Mn-rich Cantor alloy thin film down to the atomic scale N2 - The huge atomic heterogeneity of high-entropy materials along with a possibility to unravel the behavior of individual components at the atomic scale suggests a great promise in designing new compositionally complex systems with the desired multi-functionality. Herein, we apply multi-edge X-ray absorption spectroscopy (extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES), and X-ray magnetic circular dichroism (XMCD)) to probe the structural, electronic, and magnetic properties of all individual constituents in the single-phase face-centered cubic (fcc)-structured nanocrystalline thin film of Cr20Mn26Fe18Co19Ni17 (at.%) high-entropy alloy on the local scale. The local crystallographic ordering and component-dependent lattice displacements were explored within the reverse Monte Carlo approach applied to EXAFS spectra collected at the K absorption edges of several constituents at room temperature. A homogeneous short-range fcc atomic environment around the absorbers of each type with very similar statistically averaged interatomic distances (2.54–2.55 Å) to their nearest-neighbors and enlarged structural relaxations of Cr atoms were revealed. XANES and XMCD spectra collected at the L2,3 absorption edges of all principal components at low temperature from the oxidized and in situ cleaned surfaces were used to probe the oxidation states, the changes in the electronic structure, and magnetic behavior of all constituents at the surface and in the sub-surface volume of the film. The spin and orbital magnetic moments of Fe, Co, and Ni components were quantitatively evaluated. The presence of magnetic phase transitions and the co-existence of different magnetic phases were uncovered by conventional magnetometry in a broad temperature range. KW - Magnetism KW - High-entropy alloys KW - Reverse Monte Carlo (RMC) KW - Element-specific spectroscopy KW - Extended X-ray absorption fine structure (EXAFS), KW - X-ray magnetic circular dichroism (XMCD), PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578254 DO - https://doi.org/10.1007/s12274-022-5135-3 SN - 1998-0124 SP - 5626 PB - Springer AN - OPUS4-57825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Donskyi, Ievgen A1 - Drüke, M. A1 - Silberreis, K. A1 - Lauster, D. A1 - Ludwig, K. A1 - Kühne, C. A1 - Unger, Wolfgang A1 - Böttcher, C. A1 - Herrmann, A. A1 - Dernedde, J. A1 - Adeli, M. A1 - Haag, R. T1 - Interactions of fullerene-polyglycerol sulfates at viral and cellular interfaces N2 - Understanding the mechanism of interactions of nanomaterials at biointerfaces is a crucial issue to develop new antimicrobial vectors. In this work, a series of water-soluble fullerene-polyglycerol sulfates (FPS) with different fullerene/polymer weight ratios and varying numbers of polyglycerol sulfate branches are synthesized, characterized, and their interactions with two distinct surfaces displaying proteins involved in target cell recognition are investigated. The combination of polyanionic branches with a solvent exposed variable hydrophobic core in FPS proves to be superior to analogs possessing only one of these features in preventing interaction of vesicular Stomatitis virus coat glycoprotein (VSV-G) with baby hamster kidney cells serving as a model of host cell. Interference with L-selectin-ligand binding is dominated by the negative charge, which is studied by two assays: a competitive surface plasmon resonance (SPR)-based inhibition assay and the leukocyte cell (NALM-6) rolling on ligands under flow conditions. Due to possible intrinsic hydrophobic and electrostatic effects of synthesized compounds, pico- to nanomolar half maximal inhibitory concentrations (IC50) are achieved. With their highly antiviral and anti-inflammatory properties, together with good biocompatibility, FPS are promising candidates for the future development towards biomedical applications. KW - Fullerene-Polyglycerol Sulfates KW - Fullerene KW - Biointerfaces KW - XPS PY - 2018 DO - https://doi.org/10.1002/smll.201800189 SN - 1613-6829 SN - 1613-6810 VL - 14 IS - 17 SP - 1800189, 1 EP - 7 PB - WILEY-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-44573 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 - 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 -