TY - JOUR A1 - Al-Waqfi, R. A. A1 - Khan, C. J. A1 - Irving, O. J. A1 - Matthews, Lauren A1 - Albrecht, T. T1 - Crowding Effects during DNA Translocation in Nanopipettes N2 - Quartz nanopipettes are an important emerging class of electric single-molecule sensors for DNA, proteins, their complexes, as well as other biomolecular targets. However, in comparison to other resistive pulse sensors, nanopipettes constitute a highly asymmetric environment and the transport of ions and biopolymers can become strongly directiondependent. For double-stranded DNA, this can include the characteristic translocation time and tertiary structure, but as we show here, nanoconfinement can also unlock capabilities for biophysical and bioanalytical studies at the single-molecule level. To this end, we show how the accumulation of DNA inside the nanochannel leads to crowding effects, and in some cases reversible blocking of DNA entry, and provide a detailed analysis based on a range of different DNA samples and experimental conditions. Moreover, using biotin-functionalized DNA and streptavidinmodified gold nanoparticles as target, we demonstrate in a proof-of-concept study how the crowding effect, and the resulting increased residence time in nanochannel, can be exploited by first injecting the DNA into the nanochannel, followed by incubation with the nanoparticle target and analysis of the complex by reverse translocation. We thereby integrate elements of sample processing and detection into the nanopipette, as an important conceptual advance, and make a case for the wider applicability of this device concept. KW - DNA translocation KW - Transport KW - Resistive-pulse sensing KW - Nanopores KW - Nanopipettes KW - Crowding KW - Confinement PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630448 DO - https://doi.org/10.1021/acsnano.5c01529 SN - 1936-086X VL - 19 IS - 17 SP - 1 EP - 9 PB - ACS Publications AN - OPUS4-63044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pellegrino, F. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - Unveiling Order in Graphene Oxide Synthesis Through A Design of Experiment and Chemometric Strategy Based on Tour’s Method N2 - Graphene oxide (GO), a derivative of graphene containing oxygen functional groups, shows significant potential for a wide range of applications due to its unique electrical, mechanical, and chemical properties. Traditional synthesis methods, such as Tour's method, often rely on trial-and-error, leading to variations in product quality and yield. To address these challenges, we applied Design of Experiments (DoE) to systematically investigate the effects of key synthesis parameters, including reaction temperature, reaction time, and oxidant concentration. We identified the most significant factors influencing GO characteristics using a Plackett-Burman design and chemometric analysis. Our results highlight that the oxidation level is the most critical factor, impacting outcomes observed through various characterization techniques, such as UV-Vis spectroscopy and X-Ray Diffraction. Principal Component Analysis (PCA) and Multiple Linear Regression (MLR) provided insights into the synthetic parameters most strongly affecting material properties. While some findings aligned with expectations, others were counterintuitive. For instance, oxidation temperature had a minimal effect on the final material characteristics and may not need to be prioritized in the synthesis process. On the other hand, stirring was found to enhance the homogeneity of the material and promote more uniform oxidation. This study demonstrates the effectiveness of DoE in the controlled production of graphene oxide, offering a reliable framework for manufacturing high-quality GO tailored to specific applications. By minimizing time and resource consumption, this approach is increasingly relevant in the context of materials science, which demands higher quality, safety and sustainability standards. T2 - Joint Regulatory Risk Assessors Summit – Advancing Safety & Sustainability Assessments of Advanced Materials CY - Paris, France DA - 19.06.2025 KW - Graphene oxide KW - Chemometry KW - UV-Vis KW - XRD KW - XPS KW - EDX PY - 2025 UR - https://macrame-project.eu/macrame-meetings-workshops/jointrras/#Agenda AN - OPUS4-63676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Xing, Na A1 - Er, Jasmin A1 - Vidal, Ricardo M. A1 - Khadka, Sandhya A1 - Schusterbauer, Robert A1 - Rosentreter, Maik A1 - Etouki, Ranen A1 - Ahmed, Rameez A1 - Page, Taylor A1 - Nickl, Philip A1 - Bawadkji, Obida A1 - Wiesner, Anja A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Ludwig, Kai A1 - Trimpert, Jakob A1 - Donskyi, Ievgen T1 - Scalable covalently functionalized black phosphorus hybrids for broadspectrum virucidal activity N2 - At the onset of viral outbreaks, broad-spectrum antiviral materials are crucial before specific therapeutics become available. We report scalable, biodegradable black phosphorus (BP) hybrids that provide mutation-resilient virucidal protection. BP sheets, produced via an optimized mechanochemical process, are covalently functionalized with 2-azido-4,6-dichloro- 1,3,5-triazine to form P=N bonds. Fucoidan, a sulfated polysaccharide with intrinsic antiviral activity, and hydrophobic chains are then incorporated to achieve irreversible viral deactivation. The material exhibits strong antiviral inhibition and complete virucidal activity against multiple viruses, including recent severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants. It maintains high biocompatibility, remains effective against viral mutations, and is shelf stable for at least five month. The combination of biodegradability, scalable synthesis, and synergistic antiviral and virucidal mechanisms establishes BP-conjugates as a new class of highly efficient antivirals. They offer a broad spectrum antiviral solutions that could bridge the gap between antiviral medicines and general antiseptics. KW - Black phosphorus KW - Antiviral materials KW - Functionalization KW - Biodegradability KW - Sheets PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652941 DO - https://doi.org/10.48550/arXiv.2510.12854 SN - 2331-8422 SP - 1 EP - 22 PB - Cornell University CY - Ithaca, NY AN - OPUS4-65294 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - The role of Critical Raw Materials in Advanced Materials for the Energy Transition N2 - The energy transition needs advanced materials, especially for batteries, solar cells, and fuel cells. Therefore, critical raw materials are necessary. In this presentation the use of critcal raw materials and strategies for the optimisation of their use are discussed. T2 - Critical Raw Material Workshop during VAMAS Annual Meeting CY - Teddington, United Kingdom DA - 17.09.2025 KW - Advanced solar cells KW - Iridium oxide KW - Aerogels KW - Advanced carbon materials PY - 2025 AN - OPUS4-64290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Mühlbauer, Michaela A1 - Rossi, Andrea A1 - Pellegrino, Francesco A1 - Zurutuza, Amaia A1 - Radnik, Jörg A1 - Meier, Florian A1 - Hodoroaba, Vasile-Dan T1 - Morphological Analysis of Graphene Oxide by Scanning Electron Microscopy and Correlative Field-flow Fractionation Coupled with Multi-angle Light Scattering N2 - In this paper graphene related 2D materials (GR2M) arre investigated by centrifugal field flow fractioning (CF3) and SEM. Three materials were selected as case studies (CS): graphene „HD-G (CS I), graphene oxide UniTo“ (CS II), and graphene oxide „Graphenea“ (CS III). For CS I particles were evaluated as constituent particles in agglomerates, for the other two materials only isolated (non aggregated/agglomerated) flakes were considered for determination of the area equivalent circular diameter (ECD). Size analysis of all three materials was carried out by CF3 coupled with MALS (Multi-Angle Light Scattering). For evaluation, it was found that the data obtained was best suited to a disc model. Results are in good agreement when compared to the sizes obtained before CF3 analysis. CS II material is too heterogenous to accurately determine flake size by imaging. CF3 coupled with MALS enables to assess fractions within the highly heterogenous material of CS II. Imaging of the material in CS III after CF3 measurement indicates that the procedure is non-destructive. This could not be verified for the CS‘s I & II As a next step we plan to analyse the fractionated samples by imaging them within a SEM wet-cell. KW - 2D Materials KW - SEM KW - Centrifugal field flow fractionation (CF3) KW - Imaging KW - Size distribution PY - 2025 DO - https://doi.org/10.1093/mam/ozaf048.222 VL - 31 IS - 7 SP - 442 EP - 443 PB - Oxford Academic AN - OPUS4-63804 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Methodologies implemented to measure key properties of graphene and other 2D materials N2 - The key properties and suitable measurement methods for the characterization of graphene-related 2D materials are presented. A case study will be discussed about the chemical characterisation of functionalised graphene used in inks along the production chain. T2 - European-African Graphene Workshop CY - Parys, South Africa DA - 26.11.2025 KW - X-ray photoelectron spectroscoyp KW - Raman spectroscopy KW - Defects KW - Surface Chemistry PY - 2025 AN - OPUS4-64959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Liaison Report ISO/TC 229 Nanotechnology for ISO/TC 202 Microbeam Analysis and vice-versa N2 - The liaison between the ISO technical committees TC 229 Nanotechnologies and TC 202 Microbeam analysis is described in detail with highlight on the projects under development and published since 2024 and which involve input /knowledge from ISO/TC 202. T2 - 32nd Plenary Meeting of ISO/TC 202 Microbeam Analysis CY - London, United Kingdom DA - 28.10.2025 KW - Nanotechnology KW - Microabeam analysis KW - Standardisation KW - ISO PY - 2025 AN - OPUS4-64551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Energy-Dispersive X-Ray Spectrometry (EDS) on GR2Ms for Routine/Standardized Elemental Analysis N2 - The elemental analysis of solid matter by means of the Energy-Dispersive X-Ray Spectrometry (EDS) is meanwhile posible as a quick (seconds!) and more and more accurate analysis via standardsless (instantaneous) quantification. The sensitivity & quantification accuracy for light elements (C, O,..) has significantly increased in the recent years. The availability via table-top SEMs with incorporated EDS is also enhanced. Further, the EDS analysis at an SEM is well-standardized, see ISO/TC 202 Microbeam Analysis & VAMAS/ TWA 37 Quantitative Microstructural Analysis in good liaisonships with ISO/TC 229 Nanotechnologies. It is demostrated that key parameters such as oxygen-to-carbon atomic-% ratio and impurities can be realibly measured, with XPS as a reference method. Various EDS spectrometers and analysis conditions are tested and the validity of the EDS quantification of an ionic liquid of well-defined chemical composition is demonstrated. Next steps are: launch of a corresponding VAMAS interlaboratory comparison and discussions within ISO/TC 202 Microbeam Analysis. T2 - 32nd Plenary Meeting of ISO/TC 202 Microbeam Analysis CY - London, United Kingdom DA - 28.10.2025 KW - GR2M KW - EDS KW - Quantification KW - XPS KW - Light elements KW - 2D materials PY - 2025 AN - OPUS4-64553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Methodologies implemented to measure key properties of graphene and other 2D materials - EDX N2 - The elemental analysis of solid matter by means of the Energy-Dispersive X-Ray Spectrometry (EDS) is meanwhile posible as a quick (seconds!) and more and more accurate analysis via standardsless (instantaneous) quantification. The sensitivity & quantification accuracy for light elements (C, O,..) has significantly increased in the recent years. The availability via table-top SEMs with incorporated EDS is also enhanced. It is demostrated that key parameters such as oxygen-to-carbon atomic-% ratio and impurities can be realibly measured, with XPS as a reference method. Various EDS spectrometers and analysis conditions are tested and the validity of the EDS quantification of an ionic liquid of well-defined chemical composition is demonstrated. T2 - Advanced Materials Graphene: The implementation of SbD and SSbD CY - Parys, South Africa DA - 26.11.2025 KW - Light elements KW - EDS KW - Quantification KW - Oxygen-to-carbon ratio KW - XPS KW - Graphene-realted 2D materials PY - 2025 AN - OPUS4-64943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Energy Dispersive X Ray Spectrometry (EDS) on GR2Ms for Routine/Standardized Elemental Analysis N2 - The elemental analysis of solid matter by means of the Energy-Dispersive X-Ray Spectrometry (EDS) is meanwhile posible as a quick (seconds!) and more and more accurate analysis via standardsless (instantaneous) quantification. The sensitivity & quantification accuracy for light elements (C, O,..) has significantly increased in the recent years. The availability via table-top SEMs with incorporated EDS is also enhanced. Further, the EDS analysis at an SEM is well-standardized, see ISO/TC 202 Microbeam Analysis & VAMAS/ TWA 37 Quantitative Microstructural Analysis in good liaisonships with ISO/TC 229 Nanotechnologies. It is demostrated that key parameters such as oxygen-to-carbon atomic-% ratio and impurities can be realibly measured, with XPS as a reference method. Various EDS spectrometers and analysis conditions are tested and the validity of the EDS quantification of an ionic liquid of well-defined chemical composition is demonstrated. Next steps are: launch of a corresponding VAMAS interlaboratory comparison and discussions within ISO/TC 202 Microbeam Analysis. T2 - ISO/TC 229 Nanotechnologies Meeting Week CY - Stockholm, Sweden DA - 19.05.2025 KW - Graphene-related 2D materials (GR2M) KW - Energy-Dispersive X-Ray Spectrometry (EDS) KW - Elemental analysis KW - Quantification KW - ISO/TC 229 Nanotechnologies PY - 2025 AN - OPUS4-63190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Report VAMAS/TWA 37 "Quantitative Microstructural Analysis" & Liaison with ISO/TC 202 "Microbeam Analysis" N2 - The progress in activities on Quantitative MicroStructural Analysis under VAMAS/TWA 37 is reviewed. Particularly the liaison with the new projects within the ISO technical committee TC 202 Microbeam Analysis is presented and discussed with respect to the identification and launching corresponding VAMAS projects. The ongoing projects "Development of guidelines for reproducible TEM specimen preparation by FIB processing", "Measurement of dislocation density in metallic materials by Transmission Electron Microscope (TEM)", "Repeatability of high angular resolution electron backscatter diffraction (HR-EBSD) analysis for elastic strain measurements", "Measurement of grain size and distribution of nanocrystalline nickel by using Transmission Kikuchi Diffraction (TKD) in SEM" and the just started project "Evaluation Method of Surface Layer Quality of TEM Specimen Prepared by focused Ion Beam Processing" are presented in detail. T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 50th Steering Committee Meeting CY - London, United Kingdom DA - 15.09.2025 KW - VAMAS KW - Interlaboratory comparison KW - Microbeam Analysis KW - Electron Microscopy KW - ISO/TC 202 KW - Sample preparation PY - 2025 AN - OPUS4-64231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Deep Insights into Functionalised Nanoparticles with Photoelectron Spectroscopy N2 - Modern instrumentation X-ray photoelectron instrumentation combines soft and hard X-rays. Additonally, in the last years methods were developed for the analysis of the measurement data to elucidate the composition and thickness of coatings of nanoparticles. In this presentation four examples will be presented: quantum dots, silica-coated iron-oxide nanoparticles, mixed Fe-Ni-O nanoparticles and amine-functionalized silica nanoparticles. These different nanoparticles are used for displays, for biomedicine, for water splitting, and as additives and fillers. T2 - United Kingdom Surface Analysis Forum Meeting 2025 CY - Teddington, UK DA - 15.07.2025 KW - Simulation KW - Oxygen evolution reaction KW - Transmission electron microscopy KW - Quantitative nuclear magnetic resonance (qNMR) PY - 2025 AN - OPUS4-63733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Analysis of Nanoparticles N2 - The determination of the thickness and composition of the coating is crucial for the understanding of the properties of nanoparticles. Four different approaches will be presented: (i) numerical methods, (ii) descriptive formulae, (iii) the simulation of spectra with Monte-Carlo methods, and (iv) inelastic background analysis. The advantages and limits of these methods will be discussed. T2 - XPS Workshop CY - Teddington, United Kingdom DA - 14.07.2025 KW - Numerical simulation KW - Emperical formulae KW - Simulation KW - Inelastic background analysis PY - 2025 AN - OPUS4-63732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Interlaboratory comparisons for validated measurements of the surface chemistry of nanomaterials N2 - Interlaboratory comparisons are essential tools for validating new protocols or methods. The properties of advanced materials are largely determined by surface chemistry. Using a VAMAS interlaboratory comparison on the surface functionalization of GR2DM, it is explained what insights can be gained from such a comparison.” T2 - Nanomesure France Journee technique CY - Paris, France DA - 04.11.2025 KW - VAMAS KW - Functionalized graphene KW - X-ray photoelectron spectroscopy PY - 2025 AN - OPUS4-65002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altmann, Korinna A1 - Wimmer, Lukas A1 - Alcolea-Rodriguez, Victor A1 - Waniek, Tassilo A1 - Wachtendorf, Volker A1 - Matzdorf, Kay A1 - Ciornii, Dmitri A1 - Fengler, Petra A1 - Milczewski, Frank A1 - Otazo-Aseguinolaza, Itziar A1 - Ferrer, Manuel A1 - Bañares, Miguel A. A1 - Portela, Raquel A1 - Dailey, Lea Ann T1 - Quality-by-design and current good practices for the production of test and reference materials for micro- and nano-plastic research N2 - Understanding the environmental and human health impacts of micro- and nanoplastic pollutants is currently a high priority, stimulating intensive methodological research work in the areas of sampling, sample preparation and detection as well as intensive monitoring and testing. It is challenging to identify and quantify microplastics in complex organic matrices and concepts for nanoplastic detection are still in their infancy. All analytical techniques employed in studying micro- and nanoplastics require suitable reference materials for validation measurements, with requirements as diverse as the analytical tools used, ranging from different polymer types, size distributions and shapes of the material to the concentrations employed in different experimental set ups (ng to g amounts). The aim of this manuscript is to outline current good practices for small-scale laboratory production and characterization of suitable test and reference materials. The focus is placed on top-downfragmentation methods as well as bottom-up precipitation methods. Examples using polyethylene, polypropylene, polystyrene and polyethylene terephthalate with size distribution classes of mainly 10–1000, 1–10 and <1 μm particles will be provided. Experiences and suggestions on how to produce well-characterized micro- and nano-plastics for internal research needs will ensure that studies using the materials have robust and informative outcomes. KW - Mmicroplastics KW - Nanoplastics KW - Reference materials KW - Standard validation method PY - 2025 DO - https://doi.org/10.1016/j.jhazmat.2025.139595 SN - 0304-3894 VL - 497 SP - 1 EP - 20 PB - Elsevier B.V. AN - OPUS4-63958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cosimi, Andrea A1 - Stöbener, Daniel D. A1 - Nickl, Philip A1 - Schusterbauer, Robert A1 - Donskyi, Ievgen A1 - Weinhart, Marie T1 - Interfacial nanoengineering of hydrogel surfaces via block copolymer self-assembly N2 - Synthetic polymer hydrogels are valuable matrices for biotransformations, drug delivery, and soft implants. While the bulk properties of hydrogels depend on chemical composition and network structure, the critical role of interfacial features is often underestimated. This work presents a nanoscale modification of the gel−water interface using polymer brushes via a straightforward “grafting-to” strategy, offering an alternative to more cumbersome “grafting-from” approaches. Functional block copolymers with photoreactive anchor blocks are successfully self-assembled and UV-immobilized on hydrogel substrates despite their low solid content (<30 wt %). This versatile technique works on both bulk- and surface-immobilized hydrogels, demonstrated on poly(hydroxypropyl acrylate), poly(N-isopropylacrylamide), and alginate gels, allowing precise control over grafting density. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry revealed a homogeneous bilayered architecture. By “brushing-up”, the hydrogels’ interface can be tailored to enhance protein adsorption, improve cell adhesion, or impair the diffusive uptake of small molecules into the bulk gels. This effective interfacial nanoengineering method is broadly applicable for enhancing hydrogel performance across a wide range of applications. KW - Brushing-up KW - Benzophenone KW - LCTS-type polymer KW - Poly(glycidyl ether) (PGE) KW - Fibroblast adhesion KW - XPS KW - ToF-SIMS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652966 DO - https://doi.org/10.1021/acsami.4c18632 SN - 1944-8244 VL - 17 IS - 6 SP - 10073 EP - 10086 PB - American Chemical Society (ACS) CY - Washington, DC AN - OPUS4-65296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Standardized Chemical Composition Analysis of Graphene Oxide Flakes with SEM/EDS and XPS Works Reliably N2 - Reliable quantification of the chemical composition of graphene-related 2D materials (GR2M) as powders and liquid suspensions is a challenging task. Analytical methods such as XPS, ICP-MS, TGA and FTIR are recommended in projects at standardization bodies. The parameters to be measured are also defined, e.g. the oxygen-to-carbon (O/C) concentration ratio, the trace metal impurities, or the functional groups present. In this contribution, for the first time, the capability of SEM/EDS to reliably quantify the O/C ratio in a well-characterized graphene oxide (GO) material is evaluated. The robustness of the SEM/EDS results under various measurement conditions is tested by comparison to the established XPS analysis. A crucial step is the sample preparation from liquid suspension with GO flakes onto a substrate for analysis with both EDS and XPS. It is demonstrated that if a closed and enough thick drop-cast spot is deposited on a substrate, both surface-sensitive XPS analysis and bulk-characterizing EDS result in very similar elemental composition of oxygen and carbon. Hence, the theoretical, expected O/C atomic ratio values for pure GO of ~0.5 are achieved with both methods. Further, the effect of untight deposited material causing co-analysis of the silicon substrate, is evaluated for both methods, XPS and EDS. Note that all the EDS results in this study have been quantified standardless. The standard measurement procedure including the GO material considered here as a candidate reference material will make a significant contribution to analyse reliably the chemical composition of GR2M with SEM/EDS as one of the most widely used methods in analytical laboratories. T2 - Graphene Week 2025 CY - Vicenza, Italy DA - 22.09.2025 KW - EDX KW - Graphene-related 2D materials KW - O/C ratio KW - Standardisation KW - Samle preparation KW - XPS PY - 2025 AN - OPUS4-64261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Sahre, Mario A1 - Corrao, Elena A1 - Pellegrino, Francesco A1 - Hodoroaba, Vasile-Dan T1 - Wire-Print as a Sample Preparation Procedure Suitable for Accurate Morphological Characterization of Constituent Particles for Graphene-Related 2D-Materials N2 - In this study we have systematically tested the efficacy of a new deposition procedure for graphene-related 2D materials (GR2M’s) from liquid suspension onto a substrate for quantitative analysis of their size and shape distribution with electron microscopy. The technique is an extension of the conventional drop-casting method, and we have designated it “wire-print” deposition. It consists of two steps, first one being usual drop-casting on a copper substrate and second one involving a thin copper wire with a sub-mm diameter being dipped into the deposited droplet and retracted with a corresponding half-spherical droplet attached on its tip and final deposition of this entire nL-amount of suspension onto e.g. a silicon wafer for microscopical, detailed analysis. 11 series of such a wire-print deposition for a graphene-based ink have been considered, whereby various conditions (treatment of the starting suspension) have been experimented with a repetition of up to 10 times per condition, all together 86 spots on a silicon wafer of 10 mm x 10 mm. The evaluation of one series of 8 repeated wire-print depositions reveal that the deposited spots are visualized with SEM. The weak presence of coffee-rings, irregular spot shape, and presence of agglomerates should be noticed. Both the mean value of the 8 ECD distributions and the total number of flakes deposited in each spot show a variance in the range of 17% and 22%, respectively. In the context of accurate analysis of such challenging complex materials these numbers can be considered as excellent and demonstrate the high benefit of the wire-print deposition for accurate morphological measurements on GR2M’s. KW - Sample preparation KW - Imaging KW - 2D materials KW - Morphology KW - Size distribution PY - 2025 DO - https://doi.org/10.1093/mam/ozaf048.219 VL - 31 IS - 7 SP - 436 EP - 437 PB - Oxford Academic AN - OPUS4-63821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Habibimarkani, Heydar A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - John, Elisabeth T1 - Probing Surface Changes in Fe–Ni Oxide Nanocatalysts with a ToF-SIMS-Coupled Electrochemistry Setup and Principal Component Analysis N2 - Understanding catalyst surface dynamics under operating conditions is essential for improving electrocatalytic performance. Here, we present a novel approach combining electrochemical treatment with contamination-free transfer to Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), followed by principal component analysis (PCA), to probe surface and interfacial changes in Ni–Fe oxide nanoparticles stabilized by polyvinylpyrrolidone (PVP) during the oxygen evolution reaction (OER). The surface analysis at three distinct treatment stages revealed distinct chemical fingerprints across pristine nanoparticles, after exposure to 1 M KOH electrolyte, and after cyclic voltammetry treatment. The results highlight a progressive transition from ligand-rich to ligand-depleted interfaces, with PVP-related fragments dominant in the early stages and metal- and electrolyte-derived species emerging after activation. Complementary ToF-SIMS analysis of electrolyte deposited on Si wafers after each treatment step confirms the concurrent leaching of PVP and Fe–Ni-based fragments during OER. These findings underscore the dynamic nature of catalyst–electrolyte interfaces and demonstrate a robust strategy for monitoring surface-sensitive chemical changes associated with the nanoparticles, especially during the initial cycles of the OER. KW - Fe-Ni oxide KW - Nanocatalysts KW - ToF-SIMS KW - Electrochemistry KW - PCA (principal component analysis) KW - OER PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652667 DO - https://doi.org/10.1021/acs.analchem.5c03894 SN - 0003-2700 SP - 1 EP - 8 PB - American Chemical Society (ACS) AN - OPUS4-65266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - Nano and Advanced Materials - Competences at BAM and perspectives N2 - This presentation gives an overview about the competencies and the characterization possibilities of nanoparticles at BAT, based on this the development of the OECD TG 125 at BAM. It further describes research activities at BAM concerning the characterization of nanoparticles and the way to the digital representation of these characterization possibilities. It concludes with the challenges of a digital product passport (DPP) for nanomaterial based products and the need of a digital materials passport (DMP). Finally, the activities of BAM are presented which address the former mentioned challenges from ESRP and DPP. T2 - Austausch Helmholtz Hereon / Digipass & BAM CY - Berlin, Germany DA - 07.07.2025 KW - Nanomaterials KW - ESPR KW - DPP KW - Nano KW - Advanced Materials PY - 2025 AN - OPUS4-64974 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -