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 - Correlating HR-TEM and XPS to elucidate the core-shell structure of ultrabright CdSE/CdS semiconductor quantum dots N2 - Controlling the 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 application-relevant functionality like a high photoluminescence (PL) quantum yield. This calls for a whole nanoobject approach. Moreover, the thickness of the organic coating remains often unclear. 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. The results of the different methods match very well within the different measurement uncertainties. Additionally, results obtained with energy-resolved XPS using excitation energies between 200 eV and 800 eV are discussed with respect to a potential core/shell intermixing. Moreover, the future application potential of this approach correlating different sizing and structural methods is discussed considering the method-inherent uncertainties and other core/multi-shell nanostructures. T2 - E-MRS Fall Meeting CY - Online meeting DA - 20.09.2021 KW - Core-shell nanoparticles KW - Quantum dots KW - High-resolution transmission electron microscopy KW - X-ray Photoelectron Spectroscopy PY - 2021 AN - OPUS4-53365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of CeO2/Co3O4 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of CeO2/Co3O4 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - HAXPES KW - XPS KW - SEM KW - Nanoparticles KW - CeO2/Co3O4 PY - 2023 DO - https://doi.org/10.5281/zenodo.7989698 PB - Zenodo CY - Geneva AN - OPUS4-57760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of Fe3O4 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of Fe3O4 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - HAXPES KW - XPS KW - SEM KW - Fe3O4 KW - Nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7990085 PB - Zenodo CY - Geneva AN - OPUS4-57759 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 - 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 - CONF A1 - Radnik, Jörg T1 - Reliable measurements of the chemical composition of graphene-related 2D materials with X-ray photoelectron spectroscopy N2 - Graphene and related 2D materials (GR2Ms) are now entering an exciting phase of commercialization and use in products. Graphene nanoplatelets (GNPs) can be obtained in rather large quantities, but the properties of these industrially produced powders can vary depending on the production method, and even from batch to batch. Understanding and optimizing the surface chemistry of GNPs, modified through chemical functionalization processes is crucial, because it affects their dispersibility in solvents and matrices for the purpose of embedding them into real-world products. Therefore, reliable and repeatable measurements of the surface chemistry of functionalized GNPs are an important issue for suppliers as well as users of these materials. To address these concerns, international documentary ISO standards for measurement methodologies are under development which incorporate protocols that are becoming widely accepted in the community. Recently, it was shown that pelletizing led to lower average O/C atomic ratios than those measured for powders [1]. In another study, the influence of the morphology on the degree of functionalization was shown [2]. As expected, a higher degree of functionalization was detected for smaller GNPs. The functionalization was located at the outermost surfaces of the GNPs by comparing experiments using photoelectron with soft (Al Kα, 1.486 keV) and hard X-rays (Cr Kα, 5.405 keV). Therefore, it is important for those using GNPs to understand both the physical and chemical properties of these particles, when considering their use in different applications. The next step for reliable characterization protocols was the realization of an interlaboratory comparison under the auspices of VAMAS (Versailles Project on Advanced Materials and Standards) with 22 participating laboratories from all over the world. Samples of oxygen-, nitrogen-, and fluorine- functionalized GNPs were provided to the participants along with a measurement protocol. Participants were asked to prepare the samples as powders on a tape, powders in a sample holder recess, or as pellets. The lower measured O/C ratio reported for pelletized samples [1] was confirmed. The lowest scattering of the results was observed for the powders measured in the recess (Fig. 1). Furthermore, an influence of the humidity on the results was observed. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - Interlaboratory Comparison KW - Functionalized graphene KW - Sample preparation PY - 2024 AN - OPUS4-60533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peters, R. A1 - Elbers, I. A1 - Undas, A. A1 - Sijtsma, E. A1 - Briffa, S. A1 - Carnell-Morris, P. A1 - Siupa, A. A1 - Yoon, T.-H. A1 - Burr, L. A1 - Schmid, D. A1 - Tentschert, J. A1 - Hachenberger, Y. A1 - Jungnickel, H. A1 - Luch, A. A1 - Meier, F. A1 - Kocic, J. A1 - Kim, J. A1 - Park, B. C. A1 - Hardy, B. A1 - Johnston, C. A1 - Jurkschat, K. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Lynch, I. A1 - Valsami-Jones, E. T1 - Benchmarking the ACEnano toolbox for characterisation of nanoparticle size and concentration by interlaboratory comparisons N2 - ACEnano is an EU-funded project which aims at developing, optimising and validating methods for the detection and characterisation of nanomaterials (NMs) in increasingly complex matrices to improve confidence in the results and support their use in regulation. Within this project, several interlaboratory comparisons (ILCs) for the determination of particle size and concentration have been organised to benchmark existing analytical methods. In this paper the results of a number of these ILCs for the characterisation of NMs are presented and discussed. The results of the analyses of pristine well-defined particles such as 60 nm Au NMs in a simple aqueous suspension showed that laboratories are well capable of determining the sizes of these particles. The analysis of particles in complex matrices or formulations such as consumer products resulted in larger variations in particle sizes within technologies and clear differences in capability between techniques. Sunscreen lotion sample analysis by laboratories using spICP-MS and TEM/SEM identified and confirmed the TiO2 particles as being nanoscale and compliant with the EU definition of an NM for regulatory purposes. In a toothpaste sample orthogonal results by PTA, spICP-MS and TEM/SEM agreed and stated the TiO2 particles as not fitting the EU definition of an NM. In general, from the results of these ILCs we conclude that laboratories are well capable of determining particle sizes of NM, even in fairly complex formulations. KW - Nanomaterials KW - Benchmarking KW - Inter-laboratory comparison KW - ACEnano KW - Characterisation KW - Size KW - Concentration PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531852 DO - https://doi.org/10.3390/molecules26175315 SN - 1420-3049 VL - 26 IS - 17 SP - 1 EP - 23 PB - MDPI CY - Basel AN - OPUS4-53185 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - ToF-SIMS at advanced materials - from nano to energy N2 - The basic principles of ToF-SIMS will be explained. Examples of the use of ToF-SIMS for the investigation of titania and core-shell nanoplastic will be given. Furhtermore, 3d reconstruction is explained for nanoparticle research and energy-related materials. T2 - BUA Summer School Mass Spectrometry CY - Berlin, Germany DA - 04.10.2022 KW - ToF-SIMS KW - Nanomaterials KW - Imaging PY - 2022 AN - OPUS4-55897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nickl, Philip A1 - Radnik, Jörg A1 - Azab, W. A1 - Donskyi, Ievgen T1 - Surface characterization of covalently functionalized carbon-based nanomaterials using comprehensive XP and NEXAFS spectroscopies N2 - Reliable and straightforward characterization and analysis of carbon-based nanomaterials on the atomic level is essential to exploring their potential for application. Here we use a combination of highly surface sensitive x-ray photoelectron (XP) spectroscopy and near edge x-ray absorption fine structure spectroscopy (NEXAFS) to study and quantify the covalent functionalization of nanographene and single-walled carbon nanotubes with nitrene [2 + 1]-cycloaddition. With this comprehensive analytical approach, we demonstrate that the π-conjugated system of functionalized carbon-based nanomaterials is preserved according to NEXAFS analysis, which is challenging to prove with XP spectroscopy investigation alone. Using this combination of analytical approaches, we show significant similarities after functionalization for various carbon-based nanomaterials. Both analytical methods are strongly suited to study possible post-modification reactions of functionalized carbon-based nanomaterials. KW - Graphene KW - Carbon nanotubes KW - Covalend functionalization PY - 2023 DO - https://doi.org/10.1016/j.apsusc.2022.155953 VL - 613 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-56865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of sterilized Co0.75Fe2.25O4 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterilized Co0.75Fe2.25O4 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - XPS KW - HAXPES KW - SEM KW - NanoSolveIT KW - Co0.75Fe2.25O4 nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7940769 PB - Zenodo CY - Geneva AN - OPUS4-57664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -