TY - JOUR A1 - Lange, Alyna A1 - Holtzheimer, Lea A1 - Clarke, Coby A1 - Thünemann, Andreas A1 - Taubert, Andreas T1 - Complex Self-Organization in n-Alkylammonium Sulfobetaine Zwitterions with High Thermal Stabilities and High Expansion Coefficients N2 - Sulfobetaine zwitterions made from n-alkyl dimethylamines and butanesultone yield a series of n-alkylammonium sulfobetaine zwitterions with complex self-organization behavior. The compounds are thermally quite stable and the length of the alkyl chain directly affects all phase transition temperatures of the compounds: the longer the alkyl chain, the higher the transition temperature. All compounds exhibit lamellar order and the different phases are characterized by a lower temperature orthorhombic and a higher temperature hexagonal in-plane order. The phase transition from the orthorhombic to the hexagonal phase is always associated with an increase of the long period. The phase transition is also associated with a rather high thermal expansion coefficient. KW - SAXS KW - Small-angle X-ray scattering KW - Nanostructure PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626276 DO - https://doi.org/10.1021/acs.langmuir.4c02892 SN - 1520-5827 VL - 41 SP - 4422 EP - 4434 PB - American Chemical Society (ACS) AN - OPUS4-62627 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 - JOUR A1 - Iannuzzi, Maurizio A1 - Chowdhary, Suvrat A1 - Fiedler, Holly A1 - Haoues, Kilian A1 - Schade, Boris A1 - Thünemann, Andreas A1 - Quaas, Elisa A1 - Koksch, Beate 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 - Nanostructure KW - SAXS KW - Small-angle X-ray scattering PY - 2024 SN - 1099-1387 VL - 30 IS - S2 SP - 247 EP - 248 PB - Wiley CY - New York, NY AN - OPUS4-62191 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, L. A1 - Hsiao, I-L. A1 - Ebisch, Maximilian A1 - Vidmar, J. A1 - Dreiack, N. A1 - Böhmert, L. A1 - Stock, V. A1 - Braeuning, A. A1 - Loeschner, K. A1 - Laux, P. A1 - Thünemann, Andreas A1 - Lampen, A. A1 - Sieg, H. T1 - The presence of iron oxide nanoparticles in the food pigment E172 N2 - Iron oxides used as food colorants are listed in the European Union with the number E172. However, there are no specifications concerning the fraction of nanoparticles in these pigments. Here, seven E172 products were thoroughly characterized. Samples of all colors were analyzed with a Broad spectrum of methods to assess their physico-chemical properties. Small-Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), zeta-potential, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), X-ray diffraction (XRD), Brunauer-Emmett-Teller analysis (BET), Asymmetric Flow Field-Flow Fractionation (AF4) and in vitro cell viability measurements were used. Nanoparticles were detected in all E172 samples by TEM or SAXS measurements. Quantitative results from both methods were comparable. Five pigments were evaluated by TEM, of which four had a size median below 100 nm, while SAXS showed a size median below 100 nm for six evaluated pigments. Therefore, consumers May be exposed to iron oxide nanoparticles through the consumption of food pigments. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2020 DO - https://doi.org/10.1016/j.foodchem.2020.127000 VL - 327 SP - 127000 PB - Elsevier Ltd. AN - OPUS4-50810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Rott, S. A1 - Mantion, Alexandre A1 - Graf, P. A1 - Plendl, J. A1 - Thünemann, Andreas A1 - Meier, W.P. A1 - Taubert, A. A1 - Luch, A. A1 - Reiser, G T1 - Effects of silver nanoparticles on primary mixed neural cell cultures: uptake, oxidative stress and acute calcium responses N2 - In the body, nanoparticles can be systemically distributed and then may affect secondary target organs, such as the central nervous system (CNS). Putative adverse effects on the CNS are rarely investigated to date. Here, we used a mixed primary cell model consisting mainly of neurons and astrocytes and a minor proportion of oligodendrocytes to analyze the effects of well-characterized 20 and 40 nm silver nanoparticles (SNP). Similar gold nanoparticles served as control and proved inert for all endpoints tested. SNP induced a strong size-dependent cytotoxicity. Additionally, in the low concentration range (up to 10 µg/ml of SNP), the further differentiated cultures were more sensitive to SNP treatment. For detailed studies, we used low/medium dose concentrations (up to 20 µg/ml) and found strong oxidative stress responses. Reactive oxygen species (ROS) were detected along with the formation of protein carbonyls and the induction of heme oxygenase-1. We observed an acute calcium response, which clearly preceded oxidative stress responses. ROS formation was reduced by antioxidants, whereas the calcium response could not be alleviated by antioxidants. Finally, we looked into the responses of neurons and astrocytes separately. Astrocytes were much more vulnerable to SNP treatment compared with neurons. Consistently, SNP were mainly taken up by astrocytes and not by neurons. Immunofluorescence studies of mixed cell cultures indicated stronger effects on astrocyte morphology. Altogether, we can demonstrate strong effects of SNP associated with calcium dysregulation and ROS formation in primary neural cells, which were detectable already at moderate dosages. KW - Silver nanoparticles KW - Neurons KW - Oxidative stress KW - Protein carbonyls KW - Calcium KW - Reference material KW - Nanoparticle KW - Small-angle X-ray scattering KW - SAXS PY - 2012 DO - https://doi.org/10.1093/toxsci/kfs003 SN - 1096-6080 SN - 1096-0929 VL - 126 IS - 2 SP - 457 EP - 468 PB - Oxford University Press CY - Oxford AN - OPUS4-25633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - SAXS for the determination of the size distribution of nanoparticles: Application in catalysis N2 - The open source software packages SASfit1 and McSAS2 are widely used to determine the size distribution of nanoparticles. SASfit is based on classical curve fitting. The type of size distribution needs to be provided as constraint for analysis. Very often the lognormal size distribution is useful as shown for the characterization of single- and multimodal magnetic iron oxide particles. The use of SASfit is part of efforts to standardize analyzing methods for magnetic nanoparticles within the EU project NanoMag (www.nanomag-project.eu). In contrast to SASfit, it is not necessary to provide the type of size distribution when using the program McSAS. Both programs provide tools that allow the user to estimate uncertainties of the derived size distributions. Such is helpful in the development of nanoscale reference materials for environmental, health and safety measurements. As an example, a detailed study on using SAXS in the characterization of ultra-small-silver nanoparticles is presented. These particles are useful in the catalytic reduction of 4-nitrophenol and display an adjustable activity (see Figure). Figure. Core-shell silver nanoparticles catalyze the reduction of 4-nitrophenol and display an increasing catalytic activity when stabilized with different ligands in the line bovine serum albumin (BSA), glutathione (GSH) and polyacrylic acid (PAA).5 T2 - International SAXS Symposium CY - Graz, Austria DA - 26.09.2017 KW - SAXS KW - Small-angle X-ray scattering KW - Silver nanoparticles PY - 2017 AN - OPUS4-42251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kästner, Claudia A1 - Thünemann, Andreas T1 - Tracking silver nanoparticles: ultra-small silver refunctionalizable with fluorescent biopolymers N2 - We report on the synthesis of ultra-small silver nanoparticles and their quantitative characterization by small-angle X-ray scattering. The size distribution was derived by utilizing a Monte-Carlo data evaluation procedure reported by Pauw et al. Mean volume-weighted sizes are 3 nm with a size distribution width of 18 %. The particles should be used as reference materials for comparison of the result of different analytical methods among which are field-flow fractionation (FFF), dynamic light scattering (DLS), nanoparticle tracking analysis (NTA) and electron microscopy (EM). In addition further use of the particles is foreseen for comparison of studies on the toxicology of nanoparticles. Therefore the silver nanoparticles are transfunctionalized with fluorescent marked albumin (BSA-FITC) and also thoroughly characterized. With this it is possible to track silver nanoparticles and their behavior in interaction with cells. T2 - Polydays 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - SAXS KW - Biological application KW - Ligand exchange KW - Toxicity PY - 2016 AN - OPUS4-37651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lichtenstein, D. A1 - Meyer, Th. A1 - Böhmert, L. A1 - Sieg, H. A1 - Juling, S. A1 - Thünemann, Andreas A1 - Lopies, I. E. A1 - Bräuning, A. A1 - Lampen, A. T1 - Evidence for particle-specific and coating-related uptake of silver nanoparticles N2 - Present data indicate that the quantification of silver nanoparticle internalization revealed a clear particle-specific and coatingrelated uptake. Furthermore, a high amount of silver nanoparticles is taken up in cell models of higher complexity. Thus, an underestimation of particle effects in vitro might be prevented by considering cell models with greater proximity to the in vivo situation. T2 - 52nd Congress of the European-Societies-of-Toxicology (EUROTOX) CY - Seville, Spain DA - 04.09.2016 KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Silver PY - 2017 DO - https://doi.org/10.1016/j.toxlet.2016.06.1938 SN - 0378-4274 VL - 258 SP - S267 EP - S267 PB - Elsevier Ltd. AN - OPUS4-40936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieg, H. A1 - Kästner, Claudia A1 - Krause, B. A1 - Meyer, T. A1 - Burel, A. A1 - Böhmert, L. A1 - Lichtenstein, D. A1 - Jungnickel, H. A1 - Tentschert, J. A1 - Laux, P. A1 - Braeuning, A. A1 - Estreal-Lopis, I. A1 - Gauffre, F. A1 - Fessard, V. A1 - Meijer, J. A1 - Luch, A. A1 - Thünemann, Andreas A1 - Lampen, A. T1 - Impact of an artificial digestion procedure on aluminum-containing nanomaterials N2 - Aluminum has gathered toxicological Attention based on relevant human exposure and its suspected hazardous potential. Nanoparticles from food supplements or Food contact materials may reach the human gastrointestinal tract. Here, we monitored the physicochemical fate of aluminum containing nanoparticles and aluminum ions when passaging an in vitro model of the human gastrointestinal tract. Smallangle X-ray scattering (SAXS), transmission electron microscopy (TEM), ion beam microscopy (IBM), secondary ion beam mass spectrometry (TOF-SIMS), and inductively coupled plasma mass spectrometry (ICP-MS) in the singleparticle mode were employed to characterize two aluminumcontaining nanomaterials with different particle core materials (Al0, γAl2O3) and soluble AlCl3. Particle size and shape remained unchanged in saliva, whereas strong Agglomeration of both aluminum nanoparticle species was observed at low pH in gastric fluid together with an increased ion release. The levels of free aluminum ions decreased in intestinal fluid and the particles deagglomerated, thus liberating primary particles again. Dissolution of nanoparticles was limited and substantial changes of their shape and size were not detected. The amounts of particle-associated phosphorus, chlorine, potassium, and calcium increased in intestinal fluid, as compared to nanoparticles in standard dispersion. Interestingly, nanoparticles were found in the intestinal fluid after addition of ionic aluminum. We provide a comprehensive characterization of the fate of aluminum nanoparticles in simulated gastrointestinal fluids, demonstrating that orally ingested nanoparticles probably reach the intestinal epithelium. The balance between dissolution and de novo complex formation should be considered when evaluating nanotoxicological experiments. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle PY - 2017 DO - https://doi.org/10.1021/acs.langmuir.7b02729 SN - 1520-5827 SN - 0743-7463 VL - 33 IS - 40 SP - 10726 EP - 10735 PB - Americal Chemical Society AN - OPUS4-42438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieg, H. A1 - Krause, B.-C. A1 - Kästner, Claudia A1 - Böhmert, L. A1 - Lichtenstein, D. A1 - Tentschert, J. A1 - Jungnickel, H. A1 - Laux, P. A1 - Braeuning, A. A1 - Fessard, V. A1 - Thünemann, Andreas A1 - Luch, A. A1 - Lampen, A. T1 - Cellular Effects of In Vitro-Digested Aluminum Nanomaterials on Human Intestinal Cells N2 - Aluminum (Al) can be taken up from food, packaging, or the environment and thus reaches the human gastrointestinal tract. Its toxic potential after oral uptake is still discussed. The fate of different solid and ionic Al species during the passage through the digestive tract is the focus of this research, as well as the cellular effects caused by these different Al species. The present study combines the physicochemical processing of three recently studied Al species (metallic Al0, mineral Al2O3, and soluble AlCl3) in artificial digestion fluids with in vitro cell systems for the human intestinal barrier. Inductively coupled plasma mass spectrometry (ICP-MS) and small-angle X-ray scattering (SAXS) methods were used to characterize the Al species in the artificial digestion fluids and in cell culture medium for proliferating and differentiated intestinal Caco-2 cells. Cytotoxicity testing and cellular impedance measurements were applied to address the effects of digested Al species on cell viability and cell proliferation. Microarray-based transcriptome analyses and quantitative real-time PCR were conducted to obtain a deeper insight into cellular mechanisms of action and generated indications for cellular oxidative stress and an influence on xenobiotic metabolism, connected with alterations in associated signaling pathways. These cellular responses, which were predominantly caused by formerly ionic Al species and only at very high concentrations, were not impacted by artificial digestion. A two-directional conversion of Al between ionic species and solid particles occurred throughout all segments of the gastrointestinal tract, as evidenced by the presence of nanoscaled particles. Nevertheless, this presence did not increase the toxicity of the respective Al species. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2020 DO - https://doi.org/10.1021/acsanm.9b02354 VL - 3 IS - 3 SP - 2246 EP - 2256 PB - American Chemical Society AN - OPUS4-50632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, L. A1 - Saloga, Patrick E. J. A1 - Stock, V. A1 - Böhmert, L. A1 - Braeuning, A. A1 - Thünemann, Andreas A1 - Lampen, A. A1 - Sieg, H. T1 - Environmental impact of ZnO nanoparticles evaluated by in vitro simulated digestion N2 - ZnO nanoparticles are found in different food and consumer products, and their toxicological effects are still under investigation. It is therefore important to understand their behavior in the gastrointestinal tract. Here, we used an in vitro model to assess the physicochemical fate of ZnO nanoparticles during the digestive process in artificial saliva, stomach juice, and intestinal juice. Atomic absorption spectrometry and small-angle X-ray scattering were employed to investigate two ZnO nanomaterials, one intensively characterized reference material and soluble ZnCl2 in a broad range of concentrations between 25 and 1000 μg/mL in the intestinal fluid. Because food components may influence the behavior of nanomaterials in the gastrointestinal tract, starch, milk powder, and olive oil were used to mimic carbohydrates, protein, and fat, respectively. Additionally, ion release of all Zn species was assessed in cell culture media and compared to artificial intestinal juice to investigate relevance of typical cell culture conditions in ZnO nanotoxicology. ZnCl2 as well as the ZnO species were present as particles in artificial saliva but were solubilized completely in the acidic stomach juice. Interestingly, in the intestinal fluid a concentration-independent de novo formation of particles in the nanoscale range was shown. This was the case for all particles as well as for ZnCl2, regardless of the concentration used. Neither of the food components affected the behavior of any Zn species. On the contrary, all Zn species showed a Zn-concentration-dependent ion release in common cell culture medium. This questions the suitability of cell culture studies to investigate the effect of ZnO nanoparticles on intestinal cells. Our results show that Zn-containing nanoparticles reach the intestine. This underlines the importance of determining the influence of the test environment on nanoparticle fate. KW - SAXS KW - Digestion KW - Zinc oxide KW - Nanoparticles PY - 2020 DO - https://doi.org/10.1021/acsanm.9b02236 VL - 3 IS - 1 SP - 724 EP - 733 AN - OPUS4-50288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Juling, S. A1 - Böhmert, L. A1 - Lichtenstein, D. A1 - Oberemm, A. A1 - Creutzenberg, O. A1 - Thünemann, Andreas A1 - Braeuning, A. A1 - Lampen, A. T1 - Comparative proteomic analysis of hepatic effects induced by nanosilver, silver ions and nanoparticle coating in rats N2 - The presence of nano-scaled particles in food and food-related products has drawn attention to the oral uptake of nanoparticles and their interactions with biological systems. In the present study, we used a toxicoproteomics approach to allow for the untargeted experimental identification and comparative analysis of cellular Responses in rat liver after repeated-dose treatment with silver nanoparticles, ions, and the coating matrix used for particle stabilization. The proteomic analysis revealed treatment-related effects caused by exposure to silver in particulate and ionic form. Both silver species induced similar patterns of signaling and metabolic alterations. Silver-induced cellular alterations comprised, amongst others, proteins involved in metal homeostasis, oxidative stress response, and energy metabolism. However, we discovered that secondary nano-scaled structures were formed from ionic silver. Furthermore, also the coating matrix alone gave rise to the formation of nano-scaled particles. The present data confirm, complement, and extend previous knowledge on silver toxicity in rodent liver by providing a comprehensive proteomic data set. The observation of secondary particle formation from nonparticle controls underlines the difficulties in separating particle-, ion-, and matrix coating-related effects in biological systems. Awareness of this issue will support proper evaluation of nanotoxicology-related data in the future. KW - Silver nanoparticles KW - Small-angle X-ray scattering KW - SAXS PY - 2018 DO - https://doi.org/10.1016/j.fct.2018.01.056 SN - 0278-6915 SN - 1873-6351 VL - 113 SP - 255 EP - 266 PB - Elsevier AN - OPUS4-44563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Löwa, N. A1 - Knappe, Patrick A1 - Wiekhorst, F. A1 - Eberbeck, D. A1 - Thünemann, Andreas A1 - Trahms, L. T1 - Hydrodynamic and magnetic fractionation of superparamagnetic nanoparticles for magnetic particle imaging N2 - Resovist® originally developed as a clinical liver contrast agent for Magnetic Resonance Imaging exhibits also an outstanding performance as a tracer in Magnetic Particle Imaging (MPI). In order to study the physical mechanism of the high MPI performance of Resovist®, we applied asymmetric flow field–flow fractionation (A4F) and static magnetic fractionation (SMF) to separate Resovist® into a set of fractions with defined size classes. As A4F based on an elution method separates MNP according to their hydrodynamic size, SMF fractionates a particle distribution by its magnetic moment. The obtained fractions of both separation techniques were then magnetically characterized by magnetorelaxometry measurements to extract the corresponding effective magnetic anisotropy and hydrodynamic size distribution parameters. Additionally, the MPI performance of each fraction was assessed using magnetic particle spectroscopy. With both separation techniques fractions (normalized to their iron amount) an MPI signal gain of a factor of two could be obtained, even though the distribution of effective anisotropy and hydrodynamic size were significantly different. Relating these findings to the results from magnetic characterization allows for a better understanding of the underlying mechanisms of MPI performance of Resovist®. This knowledge may help to improve the design of novel MPI tracers and development of separation methods. KW - Superparamagnetic nanoparticles KW - Asymmetric flow field–flow fractionation KW - Magnetic particle spectroscopy KW - Magnetorelaxometry KW - Magnetic separation KW - Magnetic particle imaging KW - Resovist® KW - Nanotechnology KW - SAXS KW - Nanoparticles PY - 2015 DO - https://doi.org/10.1016/j.jmmm.2014.08.057 SN - 0304-8853 VL - 380 SP - 266 EP - 270 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-32562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fenger, A. A1 - Fertitta, E. A1 - Kirmse, H. A1 - Thünemann, Andreas A1 - Rademann, K. T1 - Size dependent catalysis with CTAB-stabilized gold nanoparticles N2 - CTAB-stabilized gold nanoparticles were synthesized by applying the seeding-growth approach in order to gain information about the size dependence of the catalytic reduction of p-nitrophenol to p-aminophenol with sodium borohydride. Five different colloidal solutions of stabilized gold nanoparticles have been characterized by TEM, AFM, UV-Vis, SAXS, and DLS for their particle size distributions. Gold nanoparticles (mean sizes: 3.5, 10, 13, 28, 56 nm diameter) were tested for their catalytic efficiency. Kinetic data were acquired by UV-Vis spectroscopy at different temperatures between 25 and 45 °C. By studying the p-nitrophenol to p-aminophenol reaction kinetics we determined the nanoparticle size which is needed to gain the fastest conversion under ambient conditions in the liquid phase. Unexpectedly, CTAB-stabilized gold nanoparticles with a diameter of 13 nm are most efficient. KW - Nanoparticle KW - Small-angle X-ray scattering KW - SAXS PY - 2012 DO - https://doi.org/10.1039/c2cp40792b SN - 1463-9076 SN - 1463-9084 VL - 14 IS - 26 SP - 9343 EP - 9349 PB - The Royal Soc. of Chemistry CY - Cambridge AN - OPUS4-26071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Saadeh, Qais A1 - Pauw, Brian Richard A1 - Thünemann, Andreas T1 - In-situ SAXS techniques N2 - This project studies the orientation of nanoparticles under the influence of external stimuli such as electric fields, magnetic fields and ultra-sonic vibrations. A set of functional sample holders that fit inside the sample chamber of a state-of-the-art Small Angle X-ray Scattering (SAXS) machine, called the “Multi-scale Analyzer for Ultrafine Structures” (MAUS). The MAUS has been custom engineered to serve as a miniaturized Synchrotron, thus enabling standard material to be characterized to a high standard. Our work is needed to detail the fine characterization of reference nano-particles, not only on the nano-scale, but also coupled with external agents. A second aim of this project is to verify a few proof-of-concept designs for the alignment of nano-particles. Where the alignment of nano-particles In-Situ is intended to further develop 3D printing technologies, and SAXS is an ideal choice to study the alignment of an oriented ensemble. For more information about the MAUS; https://www.bam.de/Content/DE/Pressemitteilungen/2018/AnalyticalSciences/2018-01-31-mit-maus-an-die-spitze-der-nano-forschung.html T2 - NanoWorkshop 2018 (Workshop on Reference Nanomaterials. Current situation and needs: development, measurement, standardization) CY - Berlin, Germany DA - 14.05.2018 KW - SAXS KW - Nano-particles alignment KW - Magnetic nano-particles PY - 2018 AN - OPUS4-44912 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abram, Sarah-Luise A1 - Mrkwitschka, Paul A1 - Thünemann, Andreas A1 - Radnik, Jörg A1 - Häusler, I. A1 - Bresch, Harald A1 - Hodoroaba, Vasile-Dan A1 - Resch-Genger, Ute T1 - Iron Oxide Nanocubes as a New Certified Reference Material for Nanoparticle Size Measurements N2 - The rational design and increasing industrial use of nanomaterials require a reliable characterization of their physicochemical key properties like size, size distribution, shape, and surface chemistry. This calls for nanoscale reference materials (nanoRMs) for the validation and standardization of commonly used characterization methods closely matching real-world nonspherical nano-objects. This encouraged us to develop a nonspherical nanoRM of very small size consisting of 8 nm iron oxide nanocubes (BAM-N012) to complement spherical gold, silica, and polymer nanoRMs. In the following, the development and production of this nanoRM are highlighted including the characterization by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) as complementary methods for size and shape parameters, homogeneity and stability studies, and calculation of a complete uncertainty budget of the size features. The determination of the nanocubes’ edge length by TEM and SAXS allows a method comparison. In addition, SAXS measurements can also provide the mean particle number density and the mass concentration. The certified size parameters, area equivalent circular diameter and square edge length, determined by TEM with a relative expanded uncertainty below 9%, are metrologically traceable to a natural constant for length, the very precisely known (111) lattice spacing of silicon. Cubic BAM-N012 qualifies as a certified nanoRM for estimating the precision and trueness, validation, and quality assurance of particle size and shape measurements with electron microscopy and SAXS as well as other sizing methods suitable for nanomaterials. The production of this new iron oxide nanocube RM presents an important achievement for the nanomaterial community, nanomaterial manufacturers, and regulators. KW - Certification KW - SAXS KW - Homogeneity KW - Nano KW - Particle KW - Iron oxide KW - Quality assurance KW - Reference material KW - Size KW - Electron microscopy KW - Stability KW - Shape PY - 2023 DO - https://doi.org/10.1021/acs.analchem.3c00749 SN - 0003-2700 VL - 95 IS - 33 SP - 12223 EP - 12231 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-58176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Abram, Sarah-Luise A1 - Thünemann, Andreas A1 - Rühle, Bastian A1 - Radnik, Jörg A1 - Bresch, Harald A1 - Resch-Genger, Ute A1 - Hodoroaba, Vasile-Dan T1 - The Role of Electron Microscopy in the Development of Monodisperse Cubic Iron Oxide Nanoparticles as Certified Reference Material for Size and Shape N2 - BAM is currently building up a platform of novel nanoRMs relying on iron oxide nanoparticles of different shape, size and surface chemistry. Iron oxide was chosen as a core material because of its relevance to the material and life sciences. As a first candidate of this series, we present cubic iron oxide nanoparticles with a nominal edge length of 8 nm. These particles were synthesized by thermal decomposition of iron oleate in high boiling organic solvents adapting well-known literature procedures. After dilution to a concentration suitable for electron microscopy (TEM and SEM) as well as for small-angle X-ray scattering (SAXS) measurements, the candidate nanoRM was bottled and assessed for homogeneity and stability by both methods following the guidelines of ISO 17034 and ISO Guide 35. The particle sizes obtained by both STEM-in-SEM and TEM are in excellent agreement with a minimum Feret of 8.3 nm ± 0.7 nm. The aspect ratio (AR) of the iron oxide cubes were extracted from the images as the ratio of minimum Feret to Feret resulting in an AR of 1.18 for TEM to 1.25 for SEM. Alternatively, a rectangular bounding box was fitted originating from the minimum Feret and the longest distance through the particle in perpendicular direction. This led to AR values of 1.05 for TEM and 1.12 for SEM, respectively. The results confirm the almost ideal cubic shape. KW - Reference nanoparticles KW - Iron oxide KW - Cubical shape KW - Electron microscopy KW - SAXS KW - Nano CRM KW - Size PY - 2022 DO - https://doi.org/10.1017/S1431927622003610 SN - 1435-8115 VL - 28 IS - Suppl. 1 SP - 802 EP - 805 PB - Cambridge University Press AN - OPUS4-55599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Saloga, Patrick E. J. A1 - Thünemann, Andreas T1 - Microwave-Assisted Synthesis of Ultrasmall Zinc Oxide Nanoparticles N2 - We report on ultrasmall zinc oxide single-crystalline nanoparticles of narrow size distribution and long-term colloidal stability. These oleate-stabilized nanoparticles were synthesized using microwave-assisted synthesis for 5 min, corresponding to a 99% decrease in synthesis time, when compared to the conventional synthesis method. It was observed that the average particle radius increases from 2.6 ± 0.1 to 3.8 ± 0.1 nm upon increasing synthesis temperature from 125 to 200 °C. This change also corresponded to observed changes in the optical band gap and the fluorescence energy of the particles, from 3.44 ± 0.01 to 3.36 ± 0.01 eV and from 2.20 ± 0.01 to 2.04 ± 0.01 eV, respectively. Small-angle X-ray scattering, dynamic light scattering, and UV–vis and fluorescence spectroscopy were employed for particle characterization. Debye–Scherrer analysis of the X-ray diffraction (XRD) pattern reveals a linear increase of the crystallite size with synthesis temperature. The consideration of the convolution of a Lorentz function with a Gaussian function for data correction of the instrumental peak broadening has a considerable influence on the values for the crystallite size. Williamson–Hall XRD analyses in the form of the uniform deformation model, uniform stress deformation model, and uniform deformation energy density model revealed a substantial increase of strain, stress, and deformation energy density of the crystallites with decreasing size. Exponential and power law models were utilized for quantification of strain, stress, and deformation energy density. KW - SAXS KW - Zinc oxide KW - Microwave synthesis KW - Nanoparticles PY - 2019 DO - https://doi.org/10.1021/acs.langmuir.9b01921 SN - 0743-7463 VL - 35 IS - 38 SP - 12469 EP - 12482 PB - American Chemical Society CY - Washington, D.C., USA AN - OPUS4-49136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - A look inside nanoparticles N2 - Small-angle scattering is the method of choice when it comes to obtaining information about the interior of nanoparticles. The aim is to make nanotechnology safer. While the use of small-angle neutron scattering (SANS) is limited to a few instruments in the world, small-angle X-ray scattering (SAXS) is widely accessible, with an upward trend. The example of core-shell particles shows how simple their analysis is with data from an Anton Paar laboratory system. Here, SAXS is a central tool for the development of new reference materials based on poly(methyl) acrylate-PVDF core-shell particles. The dimensions of the cores and shells can be precisely determined. A detailed analysis makes it possible to show that the cores contain fluorinated and nonfluorinated polymers, whereas the shell consist only of PVDF. This core-shell particles with a diameter around 40 nm show a significantly higher PVDF beta phase content than the PVDF homopolymer when using an emulsion polymerization technique. This finding is of importance with respect to applications in electroactive devices. T2 - SAXS excites: International SAXS Symposium 2019 CY - Graz, Austria DA - 24.09.2019 KW - Small-angle X-ray scattering KW - SAXS KW - Nanoplastics PY - 2019 AN - OPUS4-49126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brandl, F. A1 - Lederle, F. A1 - Härter, C. A1 - Thünemann, Andreas A1 - Beuermann, S. T1 - From gaseous vinylidene fluoride to electroactive poly(vinylidene fluoride) – Inducing β-phase by formation of block copolymers and composite materials N2 - Polymeric core-shell particles were synthesized in a semi-batch emulsion polymerization process. The shell of the particles consist of PVDF with a high amount of beta-phase. Small-angle X-ray scattering (SAXS) was used to quantify the size of the cores of the particles and the thickness of the shell. T2 - Macromolecular Colloquium Freiburg CY - Freiburg, Germany DA - 20.02.2019 KW - Small-angle x-ray scattering KW - SAXS KW - Nanoparticle KW - Polymer PY - 2019 AN - OPUS4-47467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - The Single Chain Architecture of (Bio)Polymers in Contact with Nanoplastics N2 - In contrast to microplastics, little is known about nanoplastics (1 to 100 nm). In order to make the dectecability of nanoplasics more reliable, we started to develop nanoplastic reference materials. This project also aims to anser the question of how the single chain conformation of bio(polymers) changes in contact with nanoplastics. Small-angle X-ray and neutron scattering methods are suitable methods for studing this topic. Recently the soft and hard interactions between polystyrene nanoplasics and human serum albumin corona was investigated with small-angle neutron scattering. Here we concentrate on small-angle X-ray scattering as our favorite method to study how (bio)polymers change their conformation in contact with nanoplastics. The scattering of bovine serum albumin in its native state can be detected easily. The scattering pattern of this biopolymer changes dramatically when its globular stucture changes to a coil structure. Modeling of chain conformations and the calculation of the scattering pattern is relatively easy to perform. Numerous model calculations will be provided to predict the changes of conformation of single bio(polymer) chains when in conatact with nanoplastics. These predictions will be compared with recent experimenal results from in situ measurments of bio(polymers) in contact with nanoplastics. The impact of temperature, polymer concentration and salt on the single-chain conformation changes will be discussed. T2 - PolyDays 2019 CY - Berlin, Germany DA - 11.09.2019 KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Protein KW - Nanoplastics PY - 2019 AN - OPUS4-48959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -