TY - JOUR A1 - Chowdhary, S. A1 - Moschner, J. A1 - Mikolajczak, D. J. A1 - Becker, M. A1 - Thünemann, Andreas A1 - Kästner, Claudia A1 - Klemczak, D. A1 - Stegemann, A.-K. A1 - Böttcher, C. A1 - Metrangolo, P. A1 - Netz, R. R. A1 - Koksch, B. T1 - The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation N2 - The hexapeptide hIAPP22–27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild‐type hIAPP′s toxicity to β‐cell death. In amyloid research, the role of hydrophobic and aromatic‐aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic‐aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS) to study the impact of side‐chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self‐assembly process. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Nanostructure KW - Peptide KW - Amyloid PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518632 DO - https://doi.org/10.1002/cbic.202000373 VL - 21 IS - 24 SP - 3544 EP - 3554 PB - Wiley CY - Weinheim AN - OPUS4-51863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liebig, F. A1 - Sarhan, R. M. A1 - Schmitt, C. N. Z. A1 - Thünemann, Andreas A1 - Prietzel, C. A1 - Bargheer, M. A1 - Koetz, J. T1 - Gold Nanotriangles with Crumble Topping and their Influence on Catalysis and Surface‐Enhanced Raman Spectroscopy N2 - By adding hyaluronic acid (HA) to dioctyl sodium sulfosuccinate (AOT)‐stabilized gold nanotriangles (AuNTs) with an average thickness of 7.5±1 nm and an edge length of about 175±17 nm, the AOT bilayer is replaced by a polymeric HA‐layer leading to biocompatible nanoplatelets. The subsequent reduction process of tetrachloroauric acid in the HA‐shell surrounding the AuNTs leads to the formation of spherical gold nanoparticles on the platelet surface. With increasing tetrachloroauric acid concentration, the decoration with gold nanoparticles can be tuned. SAXS measurements reveal an increase of the platelet thickness up to around 14.5 nm, twice the initial value of bare AuNTs. HRTEM micrographs show welding phenomena between densely packed particles on the platelet surface, leading to a crumble formation while preserving the original crystal structure. Crumbles crystallized on top of the platelets enhance the Raman signal by a factor of around 20, and intensify the plasmon‐driven dimerization of 4‐nitrothiophenol (4‐NTP) to 4,4′‐dimercaptoazobenzene in a yield of up to 50 %. The resulting crumbled nanotriangles, with a biopolymer shell and the absorption maximum in the second window for in vivo imaging, are promising candidates for biomedical sensing. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle KW - Gold PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503977 DO - https://doi.org/10.1002/cplu.201900745 VL - 85 IS - 3 SP - 519 EP - 526 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-50397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Saloga, Patrick E. J. A1 - Smales, Glen Jacob A1 - Clark, Adam H. A1 - Thünemann, Andreas T1 - Zinc Phosphate Nanoparticles Produced in Saliva N2 - This paper reports the formation of zinc phosphate nanoparticles from the artificial digestion of zinc chloride. Initially, the formation of amorphous primary particles with a mean radius of 1.1 nm is observed, alongside the formation of larger, protein stabilized aggregates. These aggregates, with a radius of gyration of 37 nm, are observed after 5 minutes of exposure to artificial saliva and are shown to be colloidally stable for a minimum time of two weeks. The initially formed primary particles are thought to consist of amorphous zinc phosphate, which is then transformed into crystalline Zn3(PO4)2·4H2O over the course of two weeks. Our results demonstrate that the interaction of inorganic salts with bodily fluids can induce the formation of de novo nanoparticles, which in turn, provides insights into how zinc‐enriched foods may also facilitate the formation of nanoparticles upon contact with saliva. As such, this may be considered as an undesirable (bio)mineralization. KW - SAXS KW - Digestion KW - Zinc phosphate PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514239 DO - https://doi.org/10.1002/ejic.202000521 IS - 38 SP - 3654 EP - 3661 PB - Wiley-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-51423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chowdhary, S. A1 - Schmidt, R. F. A1 - Sahoo, A. K. A1 - tom Dieck, T. A1 - Hohmann, T. A1 - Schade, B. A1 - Brademann-Jock, Kerstin A1 - Thünemann, Andreas A1 - Netz, R. R. A1 - Gradzielski, M. A1 - Koksch, B. T1 - Rational design of amphiphilic fluorinated peptides: Evaluation of self-assembly properties and hydrogel formation N2 - Advanced peptide-based nanomaterials composed of self-assembling peptides (SAPs) are of emerging interest in pharmaceutical and biomedical applications. The introduction of fluorine into peptides, in fact, offers unique opportunities to tune their biophysical properties and intermolecular interactions. In particular, the degree of fluorination plays a crucial role in peptide engineering as it can be used to control the characteristics of fluorine-specific interactions and, thus, peptide conformation and self-assembly. Here, we designed and explored a series of amphipathic peptides by incorporating the fluorinated amino acids (2S)-4-monofluoroethylglycine (MfeGly), (2S)-4,4-difluoroethylglycine (DfeGly) and (2S)-4,4,4-trifluoroethylglycine (TfeGly) as hydrophobic components. This approach enabled studying the impact of fluorination on secondary structure formation and peptide self-assembly on a systematic basis. We show that the interplay between polarity and hydrophobicity, both induced differentially by varying degrees of side chain fluorination, does affect peptide folding significantly. A greater degree of fluorination promotes peptide fibrillation and subsequent formation of physical hydrogels in physiological conditions. Molecular simulations revealed the key role played by electrostatically driven intra-chain and inter-chain contact pairs that are modulated by side chain fluorination and give insights into the different self-organization behaviour of selected peptides. Our study provides a systematic report about the distinct features of fluorinated oligomeric peptides with potential applications as peptide-based biomaterials. KW - Small-angle X-ray scattering KW - SAXS KW - Amyloid PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553504 DO - https://doi.org/10.1039/D2NR01648F SN - 2040-3364 VL - 14 IS - 28 SP - 10176 EP - 10189 PB - Royal Society of Chemistry AN - OPUS4-55350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Navarro, L. A1 - Thünemann, Andreas A1 - Yokosawa, T. A1 - Spiecker, E. A1 - Klinger, D. T1 - Regioselective Seeded Polymerization in Block Copolymer Nanoparticles: Post-Assembly Control of Colloidal Features N2 - Post-assembly modifications are efficient tools to adjust colloidal features of block copolymer (BCP) particles. However, existing methods often address particle shape, morphology, and chemical functionality individually. For simultaneous control, we transferred the concept of seeded polymerization to phase separated BCP particles. Key to our approach is the regioselective polymerization of (functional) monomers inside specific BCP domains. This was demonstrated in striped PS-b-P2VP ellipsoids. Here, polymerization of styrene preferably occurs in PS domains and increases PS lamellar thickness up to 5-fold. The resulting asymmetric lamellar morphology also changes the particle shape, i.e., increases the aspect ratio. Using 4-vinylbenzyl azide as co-monomer, azides as chemical functionalities can be added selectively to the PS domains. Overall, our simple and versatile method gives access to various multifunctional BCP colloids from a single batch of pre-formed particles. KW - Small-angle X-ray scattering KW - SAXS KW - Nanostructure KW - Polymer KW - Nanoparticle PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557246 DO - https://doi.org/10.1002/anie.202208084 SN - 1433-7851 VL - 61 IS - 35 SP - 1 EP - 11 PB - Wiley CY - Weinheim AN - OPUS4-55724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, M. B. A1 - Fahrenson, C. A1 - Givelet, L. A1 - Herrmann, T. A1 - Loescher, K. A1 - Böhmert, L. A1 - Thünemann, Andreas A1 - Braeuning, A. A1 - Sieg, H. T1 - Beyond microplastics ‑ investigation on health impacts of submicron and nanoplastic particles after oral uptake in vitro N2 - The continuously increasing use of plastics is supposed to result in a rising exposure of MNPs to humans. Available data on human health risks of microplastics after oral uptake increased immensely in the past years and indicates very likely only low risks after oral consumption. Concerning nanoplastics, uptake, transport and potential adverse effects after oral uptake are less well understood. This study aims to investigate differences between microplastic particles and particles in the submicron- and nanoscaled size derived from food-relevant polymers with a particle size range consistent with higher potential for cellular uptake, fate, and effects when applied to human intestinal and liver cells. This work includes the development of cellular and subcellular detection methods for synthetic polymeric particles in the micro- and nanometer-range, using Scanning Electron Microscopy, Small-Angle X-ray and Dynamic Light Scattering methods, Asymmetric Flow Field Flow Fractionation, octanol-water fractionation, fluorescence microscopy and flow cytometry. Polylactic acid (250 nm and 2 μm (polydisperse)), melamine formaldehyde (366 nm) and polymethylmethacrylate (25 nm) were thoroughly characterized. The submicro- and nanoplastic test particles showed an increased uptake and transport quantity through intestinal cells. Both types of particles resulted in observed differences of uptake behavior, most likely influenced by different lipophilicity, which varied between the polymeric test materials. Toxic effects were detected after 24 h only in overload situations for the particles in the submicrometer range. This study provides further evidence for gastrointestinal uptake of submicro- and nanoplastics and points towards differences regarding bioavailability between microplastics and smaller plastic particles that may result following the ingestion of contaminated food and beverages. Furthermore, the results reinforce the importance for studying nanoplastics of different materials of varying size, surface properties, polymer composition and hydrophobicity. KW - Small-angle X-ray scattering KW - SAXS KW - nanoparticle PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550741 DO - https://doi.org/10.1186/s43591-022-00036-0 VL - 2 SP - 1 EP - 19 PB - Springer Nature AN - OPUS4-55074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Navarro, L. A1 - Thünemann, Andreas A1 - Klinger, D. T1 - Solvent Annealing of Striped Ellipsoidal Block Copolymer Particles: Reversible Control over Lamellae Asymmetry, Aspect Ratio, and Particle Surface N2 - Solvent annealing is a versatile tool to adjust the shape and morphology of block copolymer (BCP) particles. During this process, polar solvents are often used for block-selective swelling. However, such water-miscible solvents can induce (partial) solubilization of one block in the surrounding aqueous medium, thus, causing complex structural variations and even particle disassembly. To reduce the complexity in morphology control, we focused on toluene as a nonpolar polystyrene-selective solvent for the annealing of striped polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) ellipsoids. The selective stretching of PS chains produces unique asymmetric lamellae structures, which translate to an increase in the particle aspect ratio after toluene evaporation. Complete reversibility is achieved by changing to chloroform as a nonselective solvent. Moreover, surfactants can be used to tune block-selective wetting of the particle surface during the annealing; for example, a PS shell can protect the internal lamellae structure from disassembly. Overall, this versatile postassembly process enables the tailoring of the structural features of striped colloidal ellipsoids by only using commercial BCPs and solvents. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Polymer PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543731 DO - https://doi.org/10.1021/acsmacrolett.1c00665 VL - 11 IS - 3 SP - 319 EP - 335 PB - American Chemical Society AN - OPUS4-54373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Saloga, Patrick E. J. A1 - Rybak, Tina A1 - Thünemann, Andreas T1 - Microwave-Assisted Synthesis of ZnO Nanoparticles: Phase Transfer to Water N2 - Herein, a simple one-pot procedure is reported to obtain aqueous zinc oxide (ZnO) nanoparticle dispersions from ZnO nanoparticles dispersed in cyclohexane. In the process, polyoxyethylene (20) sorbitan monooleate (polysorbate 80, Tween 80) functions as a phase transfer agent and colloidal stabilizer. The particles grow in a defined manner during the transfer, presumably via coalescence. The final particle radii are tuneable in the range from 2.3 ± 0.1 nm to 5.7 ± 0.1 nm depending on the incubation time of the dispersion at 90 °C. Small-angle X-ray scattering is employed to determine the particle radius distributions before and after phase transfer. The larger ZnO particle radii are associated with a redshift of the optical bandgap and luminescence emission, as expected for semiconductor nanoparticles. The particles presented here exhibit a relative size distribution width of 20%, rendering them attractive for applications in, e.g., biology or catalysis. The latter application is demonstrated at the photocatalytic degradation of methylene blue dye. KW - SAXS KW - Small-angle X-ray scattering KW - nanoparticle PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551502 DO - https://doi.org/10.1002/adem.202101276 VL - 24 IS - 6 SP - 1 EP - 7 PB - Wiley AN - OPUS4-55150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieg, Holger A1 - Schaar, Caroline A1 - Fouquet, Nicole A1 - Böhmert, Linda A1 - Thünemann, Andreas A1 - Braeuning, Albert T1 - Particulate iron oxide food colorants (E 172) during artificial digestion and their uptake and impact on intestinal cells N2 - Iron oxide of various structures is frequently used as food colorant (E 172). The spectrum of colors ranges from yellow over orange, red, and brown to black, depending on the chemical structure of the material. E 172 is mostly sold as solid powder. Recent studies have demonstrated the presence of nanoscaled particles in E 172 samples, often to a very high extent. This makes it necessary to investigate the fate of these particles after oral uptake. In this study, 7 differently structured commercially available E 172 food colorants (2 x Yellow FeO(OH), 2 x Red Fe2O3, 1 x Orange Fe2O3 + FeO(OH) and 2 x Black Fe3O4) were investigated for particle dissolution, ion release, cellular uptake, crossing of the intestinal barrier and toxicological impact on intestinal cells. Dissolution was analyzed in water, cell culture medium and artificial digestion fluids. Small-angle X-ray scattering (SAXS) was employed for determination of the specific surface area of the colorants in the digestion fluids. Cellular uptake, transport and toxicological effects were studied using human differentiated Caco-2 cells as an in vitro model of the intestinal barrier. For all materials, a strong interaction with the intestinal cells was observed, albeit there was only a limited dissolution, and no toxic in vitro effects on human cells were recorded. KW - Toxicology KW - Nanoparticles KW - Small-angle X-ray scattering KW - SAXS PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593935 DO - https://doi.org/10.1016/j.tiv.2024.105772 VL - 96 SP - 1 EP - 12 PB - Elsevier BV AN - OPUS4-59393 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hildebrandt, Jana A1 - Taubert, Andreas A1 - Thünemann, Andreas T1 - Synthesis and Characterization of Ultra‐Small Gold Nanoparticles in the Ionic Liquid 1‐Ethyl‐3‐methylimidazolium Dicyanamide, [Emim][DCA] N2 - AbstractWe report on gold clusters with around 62 gold atoms and a diameter of 1.15±0.10 nm. Dispersions of the clusters are long‐term stable for two years at ambient conditions. The synthesis was performed by mixing tetrachloroauric acid (HAuCl4 ⋅ 3 H2O) with the ionic liquid 1‐ethyl‐3‐methylimidazolium dicyanamide ([Emim][DCA]) at temperatures of 20 to 80 °C. Characterization was performed with small‐angle X‐ray scattering (SAXS), UV‐Vis spectroscopy, and MALDI‐TOF mass spectrometry. A three‐stage model is proposed for the formation of the clusters, in which cluster growth from gold nuclei takes place according to the Lifshitz‐Slyozov‐Wagner (LSW) model followed by oriented attachment to form colloidal stable clusters. KW - Reference materials KW - SAXS KW - Gold KW - Nanoparticle KW - Small-angle X-ray scattering KW - Ionic liquid PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588203 DO - https://doi.org/10.1002/open.202300106 SN - 2191-1363 VL - 44 SP - 1 EP - 19 PB - Wiley AN - OPUS4-58820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Iannuzzi, Maurizio T1 - Rational design of polyfluorinated peptide-based materials: Self-assembly of an amphiphilic motif N2 - Generation of a pH sensitive amphiphilic block oligopeptide containing the bioactive function RGD and a library of derivatives varying the length of the hydrophobic core and the degree of side chain fluorination. Peptide rational design enables us to obtain desired features (pH sensitivity etc.). The introduction of fluorine alters a wide range of peptide properties such as secondary structure propensity, folding, thermal and metabolic stability and proteolytic resistance. The RGD function is highly effective at promoting the attachment of numerous cell types to a plethora of materials. This small sequence is the principal integrin-binding domain present within ECM proteins such as fiobronectin, vibronectin and fibrinogen. For this reason, RGD containing peptides offer several advantages for biomaterials applications. The use of RGD compared with native ECM proteins, minimized the risk of immune reactivity or pathogen transfer. Herein in this work, we present the peptide motif X6RGD and its fluoro-derivates for prospective receptor-specific drug delivery in cancer theraphy. Overall, our results demonstrate that high degree of fluorination achieved triggers a selective modification of peptide self-assembly dramatically improving the structural properties, the carrier suitability, enzimatic degradation profiles and cytotoxic features of the fluoropeptide conjugate(s). T2 - 37th European Peptide Symposium CY - Florence, Italy DA - 25.08.2024 KW - Small-angle X-ray scattering KW - SAXS KW - Nanostructure PY - 2024 DO - https://doi.org/10.17952/37EPS.2024.P1302 AN - OPUS4-62139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hewel, M. A1 - Siemann, U. A1 - Smarsly, B. A1 - Stribeck, A. A1 - Thünemann, Andreas T1 - Nachruf auf Wilhelm Ruland N2 - Mit Prof. Dr. Wilhelm Ruland starb am 3. Februar 2021 einer der letzten großen Wissenschaftler, welche die Streutheorie nach dem Zweiten Weltkrieg vorangetrieben haben. Sein zentrales Thema war die Streuung an weicher Materie. Hier lieferte er bis ins hohe Alter grundlegende Beiträge, die den Stellenwert seines Leitspruchs demonstrieren: Nichts ist praktischer als eine gute Theorie. KW - SAXS PY - 2021 VL - 20 IS - 4 SP - 50 EP - 50 PB - Wiley AN - OPUS4-52413 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - SAXS for the development of reference materials: Silver nanoparticles, a case study N2 - Today there are hundreds of products available containing silver in form of nanoparticles, so-called nanosilver. This situation and the foreseeable future growing market of nanosilver will supposedly cause an increased release of silver into the environment. In this way, silver can be also incorporated into the human body and accumulated in different organs, which can be toxic or at least an unknown risk to human health. For these reasons, it is important to constantly study materials containing silver nanoparticles, their production, application in products and technical processes, dissemination of silver nanoparticles in the environment, and effects on humans and nature. The state-of-the-art nanoparticle size and concentration characterization are illustrated in an extensive interlaboratory comparison. To guarantee the traceability of measurements and to secure the comparison of results of different analytical methods, reference materials (RM) and certified reference materials (CRM) are essential. As a case study, the objective of the presented project was to provide an aqueous suspension of silver nanoparticles as a reference material with a nominal diameter below 10 nm for application in the determination of the size and concentration of nanoparticles in an aqueous surrounding. Measurands are the particles’ diameter D, size distribution width σ, number density N, and concentration c. Target uncertainties, defined as one sigma of the measurand values, are 5% for D, 10% for σ, 20% for N, and 20% for c. The certification was carried out based on ISO 17867 and the relevant ISO-Guides to produce reference material. The process of using SAXS as a reliable method for testing homogeneity and short-term and long-term stability of the material is reported. The particle preparation is described in detail so that the user can carry out the steps of synthesis and characterization in his own laboratory if required. Optionally, one can also contact the author for the provision of the silver nanoparticles. Detailed information can be found elsewhere (BAM Certification Reports, BAM-N008 (2022)). T2 - SAXS excites CY - Graz, Austria DA - 04.04.2023 KW - Nanoparticles KW - SAXS KW - Nanosilver KW - Small-angle x-ray scattering PY - 2023 AN - OPUS4-57283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - Structure Analysis of Functional Hydrogels with Small-Angle X-ray Scattering (SAXS) N2 - Hydrogel properties are largely determined by their network structure. Here, we report on the capabilities of SAXS methods for characterizing polymer-network gels. SAXS provides rich insight into different types and levels of nanostructural inhomogeneities in these soft matter materials. The structure analysis of alginate hydrogels, typically utilized in tissue engineering applications, will be discussed in detail. T2 - Polydays 2024 CY - Berlin, Germany DA - 30.09.2024 KW - SAXS KW - Small-angle X-ray scattering KW - Polymer KW - Gel PY - 2024 AN - OPUS4-61184 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieg, H. A1 - Klusmann, L. A1 - Ellermann, A. L. A1 - Böhmert, L. A1 - Thünemann, Andreas A1 - Braeuning, A. T1 - Counterions determine uptake and effects of aluminum in human intestinal and liver cells N2 - Aluminum (Al) is highly abundant in the biosphere and can occur in different physico-chemical states. It is present in human food and undergoes transitions between dissolved and particulate species during the passage of the gastrointestinal tract. Moreover, in a complex matrix such as food different inorganic and organic counterions can affect the chemical behavior of Al following oral uptake. In this work, the effects of different counterions, namely chloride, citrate, sulfate, lactate and acetylacetonate, on Al uptake and toxicity in the human intestine are studied. The respective Al salts showed different dissolution behavior in biological media and formed nanoscaled particles correlating in reverse with the amount of their dissolved fraction. The passage through the intestinal barrier was studied using a Caco-2 Transwell® system, showing counterion-dependent variance in cellular uptake and transport. In addition, Al toxicity was investigated using Al species (Al3+, metallic Al0 and oxidic γAl2O3 nanoparticles) and counterions individually or in mixtures on Caco-2 and HepG2 cells. The strongest toxicity was observed using a combination of Al species, depending on solubility, and the lipophilic counterion acetylacetonate. Notably, only the combination of both led to toxicity, while both substances individually did not show toxic effects. A toxification of previously non-toxic Al-species by the presence of acetylacetonate is shown here for the first time. The dependency on the concentration of free Al ions was demonstrated using sodium hydrogen phosphate, which was able to counteract the toxic effects by complexing free Al ions. These findings, using Al salts as an example for a common food contaminant, underline the importance of a consideration of the chemical properties of human nutrition, especially dissolution and hydrophobicity, which can significantly influence the cellular uptake and effects of xenobiotic substances. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2022 DO - https://doi.org/10.1016/j.tiv.2021.105295 VL - 79 SP - 1 EP - 7 PB - Elsevier AN - OPUS4-54110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ihlenburg, R. B. J. A1 - Mai, T. A1 - Thünemann, Andreas A1 - Baerenwald, R. A1 - Saalwächter, K. A1 - Koetz, J. A1 - Taubert, A. T1 - Sulfobetaine Hydrogels with a Complex Multilength-Scale Hierarchical Structure N2 - Hydrogels with a hierarchical structure were prepared from a new highly water-soluble crosslinker N,N,N′,N′-tetramethyl-N,N′-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and from the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The free radical polymerization of the two compounds is rapid and yields near-transparent hydrogels with sizes up to 5 cm in diameter. Rheology shows a clear correlation between the monomer-to-crosslinker ratio and the storage and loss moduli of the hydrogels. Cryo-scanning electron microscopy, low-field nuclear magnetic resonance (NMR) spectroscopy, and small-angle X-ray scattering show that the gels have a hierarchical structure with features spanning the nanometer to the sub-millimeter scale. The NMR study is challenged by the marked inhomogeneity of the gels and the complex chemical structure of the sulfobetaine monomer. NMR spectroscopy shows how these complications can be addressed via a novel fitting approach that considers the mobility gradient along the side chain of methacrylate-based monomers. KW - Small-angle X-ray scattering KW - SAXS KW - Gel PY - 2021 DO - https://doi.org/10.1021/acs.jpcb.0c10601 SN - 1520-6106 VL - 125 IS - 13 SP - 3398 EP - 3408 PB - American Chemical Society AN - OPUS4-52403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fortes Martin, R. A1 - Thünemann, Andreas A1 - Stockmann, Jörg Manfred A1 - Radnik, Jörg A1 - Koetz, J. T1 - From Nanoparticle Heteroclusters to Filament Networks by Self-Assembly at the Water–Oil Interface of Reverse Microemulsions N2 - Surface self-assembly of spherical nanoparticles of sizes below 10 nm into hierarchical heterostructures is under arising development despite the inherent difficulties of obtaining complex ordering patterns on a larger scale. Due to template-mediated interactions between oil-dispersible superparamagnetic nanoparticles (MNPs) and polyethylenimine-stabilized gold nanoparticles (Au(PEI)NPs) at the water–oil interface of microemulsions, complex nanostructured films can be formed. Characterization of the reverse microemulsion phase by UV–vis absorption revealed the formation of heteroclusters from Winsor type II phases (WPII) using Aerosol-OT (AOT) as the surfactant. SAXS measurements verify the mechanism of initial nanoparticle clustering in defined dimensions. XPS suggested an influence of AOT at the MNP surface. Further, cryo-SEM and TEM visualization demonstrated the elongation of the reverse microemulsions into cylindrical, wormlike structures, which subsequently build up larger nanoparticle superstructure arrangements. Such WPII phases are thus proven to be a new form of soft template, mediating the self-assembly of different nanoparticles in hierarchical network-like filaments over a substrate during solvent evaporation. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Nano structure PY - 2021 DO - https://doi.org/10.1021/acs.langmuir.1c01348 VL - 37 IS - 29 SP - 8876 EP - 8885 PB - American Chemical Society AN - OPUS4-53034 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 - INPR A1 - Pauw, Brian Richard A1 - Laskina, Sofya A1 - Naik, Aakash A1 - Smales, Glen Jacob A1 - George, Janine A1 - Breßler, Ingo A1 - Benner, Philipp T1 - "Ultima Ratio": Simulating wide-range X-ray scattering and diffraction N2 - We demonstrate a strategy for simulating wide-range X-ray scattering patterns, which spans the small- and wide scattering angles as well as the scattering angles typically used for Pair Distribution Function (PDF) analysis. Such simulated patterns can be used to test holistic analysis models, and, since the diffraction intensity is on the same scale as the scattering intensity, may offer a novel pathway for determining the degree of crystallinity. The "Ultima Ratio" strategy is demonstrated on a 64-nm Metal Organic Framework (MOF) particle, calculated from Q < 0.01 1/nm up to Q < 150 1/nm, with a resolution of 0.16 Angstrom. The computations exploit a modified 3D Fast Fourier Transform (3D-FFT), whose modifications enable the transformations of matrices at least up to 8000^3 voxels in size. Multiple of these modified 3D-FFTs are combined to improve the low-Q behaviour. The resulting curve is compared to a wide-range scattering pattern measured on a polydisperse MOF powder. While computationally intensive, the approach is expected to be useful for simulating scattering from a wide range of realistic, complex structures, from (poly-)crystalline particles to hierarchical, multicomponent structures such as viruses and catalysts. KW - X-ray KW - Simulation KW - 3D Fourier Transform KW - High resolution KW - XRD KW - SAXS KW - PDF KW - Total scattering KW - X-ray scattering KW - Metal organic framework KW - Electron density map KW - FFT PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572067 DO - https://doi.org/10.48550/arXiv.2303.13435 VL - Cornell University SP - 1 EP - 12 PB - Ithaca, NY AN - OPUS4-57206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kohlbrecher, J. A1 - Breßler, Ingo T1 - SASfit 0.94.12 N2 - Small-angle scattering is an increasingly common method for characterizing particle ensembles in a wide variety of sample types and for diverse areas of application. SASfit has been one of the most comprehensive and flexible curve-fitting programs for decades, with many specialized tools for various fields. KW - Small-angle scattering KW - SAXS KW - SANS KW - Scattering pattern analysis PY - 2023 UR - https://doi.org/10.5281/zenodo.7530357 DO - https://doi.org/10.5281/zenodo.7530356 PB - Zenodo CY - Geneva AN - OPUS4-57913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Anker, A. S. A1 - Balazs, D. M. A1 - Beyer, F. L. A1 - Bienert, Ralf A1 - Bouwman, W. G. A1 - Breßler, Ingo A1 - Breternitz, J. A1 - Brok, E. S. A1 - Bryant, G. A1 - Clulow, A. J. A1 - Crater, E. R. A1 - De Geuser, F. A1 - Giudice, A. D. A1 - Deumer, J. A1 - Disch, S. A1 - Dutt, S. A1 - Frank, K. A1 - Fratini, E. A1 - Gilbert, E. P. A1 - Hahn, Marc Benjamin A1 - Hallett, J. A1 - Hohenschutz, Max A1 - Hollamby, M. J. A1 - Huband, S. A1 - Ilavsky, J. A1 - Jochum, J. K. A1 - Juelsholt, M. A1 - Mansel, B. W. A1 - Penttilä, P. A1 - Pittkowski, R. K. A1 - Portale, G. A1 - Pozzo, L. D. A1 - Ricardo de Abreu Furtado Garcia, P. A1 - Rochels, L. A1 - Rosalie, Julian A1 - Saloga, P. E. J. A1 - Seibt, S. A1 - Smith, A. J. A1 - Smith, G. N. A1 - Annadurai, V. A1 - Spiering, G. A. A1 - Stawski, Tomasz A1 - Taché, O. A1 - Thünemann, Andreas A1 - Toth, K. A1 - Whitten, A. E. A1 - Wuttke, J. T1 - The human factor - Results of a small-angle scattering data analysis round robin N2 - A Round Robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions, and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5 % and half of the population width entries within 40 %, respectively. Due to the added complexity of the structure factor, much fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 % and 86 % respectively. This Round Robin experiment highlights several causes for the discrepancies, for which solutions are proposed. KW - Round robin KW - Sall-angle scattering KW - Nanostructure quantification KW - Nanostructure KW - SAXS KW - MOUSE KW - X-ray scattering KW - Size distribution KW - Nanoparticles PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571342 DO - https://doi.org/10.48550/arXiv.2303.03772 SP - 1 EP - 23 PB - Cornell University CY - Ithaca, NY AN - OPUS4-57134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aliyah, K. A1 - Berger, A. A1 - Lazaridis, T. A1 - Appel, C. A1 - Prehal, C. A1 - Menzel, A. A1 - Guizar-Sicairos, M. A1 - Smales, Glen J. A1 - Pauw, Brian Richard A1 - Gasteiger, H. A. A1 - Gubler, L. A1 - Büchi, F. N. A1 - Eller, J. T1 - Impact of Microporous Layer Composition on the Water Content in the Membrane Electrode Assembly of Polymer Electrolyte Fuel Cells N2 - Polymer electrolyte fuel cells are paramount for future emission-free mobility. One of the vital challenges for prospering commercialization of PEFCs is water management in the cells. A microporous layer (MPL) is typically positioned between the gas Diffusion layer (GDL) and the catalyst layer (CL) to boost the cell performance and facilitate water management. In this study, three different MPLs were investigated, namely, carbon black-based MPLs with different PTFE binder contents (20 wt % PTFE as a base case and 40 wt % PTFE), as well as perforated MPLs with micron-sized pores coated on the same GDL- Substrate (Freudenberg H14). The water content in the membrane, catalyst layers (CL), and MPLs was explored using operando scanning small- and wide-angle X-ray scattering (S/WAXS). At Tcell = 80 °C, relative humidity = 100%, pabs = 3 bar, the MPL with larger pores exhibits slightly higher performance than the base case, while a considerably lower cathode CL and MPL saturation levels were observed for the MPL. In contrast, the MPL with higher amounts of PTFE binder shows lower performance than the base case, with considerably higher cathode CL and MPL saturation levels. 3D representations of how the pores could be filled in the cathode CLs were obtained from operando SAXS profiles using representative structure modeling for the different materials and operating conditions. KW - Polymer electrolyte fuel cell KW - Catalyst layer saturation KW - Microporous layer saturation KW - Membrane hydration KW - Small and wide-angle scattering KW - MOUSE KW - SAXS KW - X-ray scattering KW - Energy storage materials PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656691 DO - https://doi.org/10.1021/acsami.5c22540 SN - 1944-8244 SP - 1 EP - 17 PB - American Chemical Society (ACS) AN - OPUS4-65669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Laskina, Sofya A1 - Naik, Aakash A1 - Smales, Glen Jacob A1 - George, Janine A1 - Breßler, Ingo A1 - Benner, Philipp T1 - Jupyter notebook and VASP calculation details accompanying the manuscript: "Ultima Ratio: Simulating wide-range X-ray scattering and diffraction" N2 - Summary: This notebook and associated datasets (including VASP details) accompany a manuscript available on the ArXiv (https://doi.org/10.48550/arXiv.2303.13435) and hopefully soon in a journal as short communication as well. Most of the details needed to understand this notebook are explained in that paper with the same title as above. For convenience, the abstract is repeated here: Paper abstract: We demonstrate a strategy for simulating wide-range X-ray scattering patterns, which spans the small- and wide scattering angles as well as the scattering angles typically used for Pair Distribution Function (PDF) analysis. Such simulated patterns can be used to test holistic analysis models, and, since the diffraction intensity is presented coupled to the scattering intensity, may offer a novel pathway for determining the degree of crystallinity. The "Ultima Ratio" strategy is demonstrated on a 64-nm Metal Organic Framework (MOF) particle, calculated from $Q<0.01$\,$\mathrm{nm}^{-1}$ up to $Q\approx150$\,$\mathrm{nm}^{-1}$, with a resolution of 0.16\,\AA. The computations exploit a modified 3D Fast Fourier Transform (3D-FFT), whose modifications enable the transformations of matrices at least up to $8000^3$ voxels in size. Multiple of these modified 3D-FFTs are combined to improve the low-$Q$ behaviour. The resulting curve is compared to a wide-range scattering pattern measured on a polydisperse MOF powder. While computationally intensive, the approach is expected to be useful for simulating scattering from a wide range of realistic, complex structures, from (poly-)crystalline particles to hierarchical, multicomponent structures such as viruses and catalysts. KW - X-ray KW - Simulation KW - Scattering KW - MOUSE KW - Nanomaterials KW - XRD KW - SAXS KW - PDF KW - Total scattering KW - 3D Fourier transform KW - High resolution KW - FFT PY - 2023 DO - https://doi.org/10.5281/zenodo.7764044 PB - Zenodo CY - Geneva AN - OPUS4-57207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pütz, E. A1 - Smales, Glen Jacob A1 - Jegel, O. A1 - Emmerling, Franziska A1 - Tremel, W. T1 - Tuning ceria catalysts in aqueous media at the nanoscale: how do surface charge and surface defects determine peroxidase- and haloperoxidase-like reactivity N2 - Designing the shape and size of catalyst particles, and their interfacial charge, at the nanometer scale can radically change their performance. We demonstrate this with ceria nanoparticles. In aqueous media, nanoceria is a functional mimic of haloperoxidases, a group of enzymes that oxidize organic substrates, or of peroxidases that can degrade reactive oxygen species (ROS) such as H2O2 by oxidizing an organic substrate. We show that the chemical activity of CeO2−x nanoparticles in haloperoxidase- and peroxidaselike reactions scales with their active surface area, their surface charge, given by the ζ-potential, and their surface defects (via the Ce3+/Ce4+ ratio). Haloperoxidase-like reactions are controlled through the ζ-potential as they involve the adsorption of charged halide anions to the CeO2 surface, whereas peroxidase-like reactions without charged substrates are controlled through the specific surface area SBET. Mesoporous CeO2−x particles, with large surface areas, were prepared via template-free hydrothermal reactions and characterized by small-angle X-ray scattering. Surface area, ζ-potential and the Ce3+/Ce4+ ratio are controlled in a simple and predictable manner by the synthesis time of the hydrothermal reaction as demonstrated by X-ray photoelectron spectroscopy, sorption and ζ-potential measurements. The surface area increased with synthesis time, whilst the Ce3+/Ce4+ ratio scales inversely with decreasing ζ-potential. In this way the catalytic activity of mesoporous CeO2−x particles could be tailored selectively for haloperoxidase- and peroxidase-like reactions. The ease of tuning the surface properties of mesoporous CeO2x particles by varying the synthesis time makes the synthesis a powerful general tool for the preparation of nanocatalysts according to individual needs. KW - SAXS KW - Ceria KW - Zeta potential PY - 2022 DO - https://doi.org/10.1039/D2NR03172H SP - 1 EP - 12 PB - Royal Society of Chemistry AN - OPUS4-55649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Miyata, Ayana A1 - Tokuda, Shun A1 - Kuzumoto, Mako A1 - Lee, Guan-Sian A1 - Yamashita, Masataka A1 - Nishiguchi, Taichi A1 - Negoro, Masaki A1 - Pauw, Brian Richard A1 - Chan, Yi-Tsu A1 - Kanamori, Kazuyoshi A1 - Urayama, Kenji A1 - Sugimoto, Kunihisa A1 - Furukawa, Shuhei T1 - One-Dimensional van der Waals Porous Fibrils Assembled from Metal–Organic Polyhedra N2 - Supramolecular systems exhibit collective functions that emerge from the hierarchical assembly of individual molecular building blocks. Metal−organic polyhedra (MOPs) are a class of functional supramolecular architectures with well-defined molecular geometry and an intrinsic cavity. In recent years, considerable progress has been made in assembling MOPs into extended networks to create porous solids. However, most reported MOP assemblies are limited to three-dimensional networks, which, owing to their high-dimensional connectivity, hinder effective stress dissipation and render them brittle under mechanical stress. Here, we report the one-dimensional (1D) self-assembly of MOPs into supramolecular polymeric aerogels that combine permanent microporosity with exceptional mechanical flexibility. The reaction between amino acid-functionalized naphthalenediimide (NDI) linkers and copper salts led to the synthesis of octahedral copper-based MOPs, followed by their spontaneous self-assembly to form supramolecular gels. The corresponding aerogels converted from the gels possessed uniform 1D fibrillar networks (14.8 ± 2.2 nm in width) with intrinsic microporosity derived from individual MOP cavities. The aerogel endured 87% compressive strain without fracture, demonstrating distinct ductility. Furthermore, these fibrils in the supramolecular gels were converted to crystals after 2 weeks. Single-crystal X-ray diffraction revealed that MOPs are arranged via face-to-face interaction between octahedral MOPs to form a 1D helical chain structure. An analysis of the self-assembly process using Hansen solubility parameters unveiled that solvent conditions with high polarity and low dispersion interaction drive the formation of anisotropic assemblies. This work provides a new strategy for tailoring the mechanical properties of supramolecular materials through dimensional control of their assemblies. KW - Aerogels KW - Crystals KW - Metal organic frameworks KW - Nanofibers KW - Solvents KW - X-ray scattering KW - SAXS KW - Nanostructure KW - Small-angle X-ray scattering PY - 2026 DO - https://doi.org/10.1021/jacs.5c21654 SN - 0002-7863 SP - 1 EP - 13 PB - American Chemical Society (ACS) AN - OPUS4-65776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -