TY - CONF A1 - Knigge, Xenia T1 - Influence of Sterilization on the Surface of Nanoparticles Studied with XPS / HAXPES in Comparison to SEM / EDS N2 - Nanosafety is becoming increasingly important as nanomaterials are widely used in industrial processes and consumer products. For nanotoxicity measurements prior sterilization of the samples is necessary, but as structure activity relationships are made with properties of pristine particles, the question arises, if the sterilization process has an impact on the physico-chemical properties of nanoparticles and thus on the biological behavior. This question will be addressed in this talk. For this purpose, results from SEM and EDS measurements are combined with those of a novel lab-based HAXPES spectrometer in order to obtain a more complete picture. At the end, an influence of sterilization will be evident, which indicates a restructuring of the nanoparticles owing to sterilization. T2 - Microscopy & Microanalysis 2022 CY - Online meeting DA - 31.07.2022 KW - XPS KW - HAXPES KW - SEM KW - EDS KW - Nanoparticles PY - 2022 AN - OPUS4-55353 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 - Bonse, Jörn T1 - Chemical and topographical analyses of ps-laser generated HSFL on titanium alloy N2 - Laser-induced periodic surface structures (LIPSS) enable a large variety of different surface functionalizations for applications in the fields of optics, fluidics, tribology, or medicine. Moreover, high spatial frequency LIPSS (HSFL) provide an appealing and straightforward way for the generation of surface nanostructures featuring spatial periods even below 100 nm – far beyond the optical diffraction limit. However, the imposed surface functionalities are usually caused by both, topographic and chemical surface alterations. For exploring these effects in detail, multi-method characterization was performed here for HSFL processed on Ti-6Al-4V alloy upon irradiation with near-infrared ps-laser pulses (1030 nm wavelength, ~1 ps pulse duration, 1 – 400 kHz pulse repetition rate) under different scan processing conditions. The subsequent sample characterization involved morphological and topographical investigations by scanning electron microscopy (SEM), atomic force microscopy (AFM), stylus profilometry (SP), as well as near-surface chemical analyses by X-ray photoelectron spectroscopy (XPS), hard X-ray photoelectron spectroscopy (HAXPES) and depth-profiling time-of-flight secondary ion mass spectrometry (TOF-SIMS). The results allow to qualify the laser ablation depth, the geometrical HSFL characteristics and provide detailed insights into the depth extent and the nature of the ps-laser-induced near-surface oxidation arising from the laser-processing in ambient air and into the relevance of heat-accumulation effects at high pulse repetition rates. Moreover, the direct comparison of the HAXPES and XPS data reveals the role of surface-covering organic contaminants adsorbed from the ambient atmosphere without ion-sputter depth profiling. Furthermore, reduction of the oxides by sputtering can be avoided. T2 - SPIE Photonics Europe 2024 Conference, Symposium "Lasers and Photonics for Advanced Manufacturing" CY - Strasbourg, France DA - 07.04.2024 KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrafast laser processing KW - Nanostructures KW - Chemical analyses PY - 2024 UR - https://spie.org/photonics-europe/presentation/Chemical-and-topographical-analyses-of-ps-laser-generated-high-spatial/13005-69#_=_ AN - OPUS4-59853 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 - STEM in SEM vs SE InLens type SEM as a Reliable Analytical Pair Tool for Measurement of Nanoparticle Size and Shape Distribution N2 - In this lecture, following points are addressed: – Advantages of correlative analysis in electron microscopy – Measurement principle of the different electron microscopy modes used – Presentation of the nanomaterials used for this study – Role of sample preparation – Sequence kV variation with InLens & transmission detection of the same field-of-view – Conclusive remarks including Monte Carlo simulations T2 - Microscopy and Microanalysis 2024 CY - Cleveland, OH, USA DA - 28.07.2024 KW - Correlative analysis KW - Electron microscopy KW - Nanoparticles KW - SEM KW - STEM-in-SEM KW - Particle size distribution KW - Titanium dioxide PY - 2024 AN - OPUS4-60804 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 - VAMAS Regional Workshop in Germany N2 - An overview on the VAMAS technical working areas (TWA) and projects where Germany is active has been given. The role of VAMAS as an international pre-standardisation platform, including its intense collaboration with international bodies ISO, CEN, OECD and CCQM and national organizations like DIN has been highlighted. T2 - VAMAS Regional Workshop 2023 - What can pre-normative research do for industry? CY - Online meeting DA - 24.01.2023 KW - VAMAS KW - Advanced materials KW - Inter-laboratory comparisons KW - Regional workshop PY - 2023 UR - https://www.bam-akademie.de/kursangebot/kurs/vamas-regional-workshop-2023-23.html?lang=en AN - OPUS4-57281 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 - Hodoroaba, Vasile-Dan T1 - Quantitative Microstructural Analysis - VAMAS TWA 37 & Liaison with ISO/TC 202 Microbeam Analysis N2 - The progress in activities on Microbeam Analysis under VAMAS/TWA 37 is reviewed. Particularly the liaison with the new projects within the ISO technical committee TC 202 is presented and discussed with respect to the possibility of identifying and launching related VAMAS projects. The recently started project FIB sample processing for TEM is highlighted. Need of more promotion for the engagement of more participants from industry and academia at national, European and international level is highlighted. Also, the competition with the other technical working areas (on 'nano' or materials-related) is critically discussed. Further, a short overview of the VAMAS areas of activities is given where Germany is involved. Planed regional VAMAS Workshops in Germany in 2023 are announced. T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 47th Steering Committee Meeting CY - Torino, Italy DA - 18.10.2022 KW - VAMAS KW - Microbeam analysis KW - FIB KW - TEM KW - Sample preparation KW - EBSD PY - 2022 UR - https://amdgroup.inrim.it/events/vamas-sc-meeting-47 AN - OPUS4-56146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terborg, R. A1 - Kim, K. J. A1 - Hodoroaba, Vasile-Dan T1 - Determination of Thin Film Thickness and Composition using Energy Dispersive EPMA N2 - The thickness of thin films can be measured by various methods, e.g., profilometry, ellipsometry, atomic force microscopy (AFM), or X-ray reflectometry. For the additional determination of thin film composition, techniques like X-ray photoelectron spectroscopy (XPS) or mass spectrometry-based techniques can be used. An alternative non-destructive technique is electron probe microanalysis (EPMA). This method assumes a sample of homogenous (bulk) chemical composition, so that it cannot be usually applied to thin film samples. However, in combination with the thin film software StrataGEM, the thickness as well as the composition of such films on a substrate can be determined. This has been demonstrated for FeNi on Si and SiGe on Al2O3 film systems. For both systems five samples with different elemental composition and a reference were produced and characterised by Korean research institute KRISS using inductively coupled plasma mass spectrometry (ICP-MS), Rutherford backscattering (RBS), and transmission electron microscopy (TEM). These samples were used for an international round robin test. In 2021, a new and open-source thin film evaluation programme called BadgerFilm has been released. It can also be used to determine thin film composition and thickness from intensity ratios of the unknown sample and standards (k-ratios). In this contribution, we re-evaluated the data acquired for the FeNi and SiGe systems using the BadgerFilm software package and compared the resulting composition and thickness with the results of the established StrataGEM software and other reference methods. With the current evaluation, the BadgerFilm software shows good agreement with the composition and thickness calculated by StrataGEM and as the reference values provided by the KRISS. KW - Thin films KW - Elemental composition KW - Film thickness KW - EPMA (Electron Probe Microanalysis) PY - 2022 DO - https://doi.org/10.1017/S143192762200318X VL - 28 IS - Suppl. 1 SP - 672 EP - 673 PB - Cambridge University Press AN - OPUS4-55437 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 - VAMAS Project A33: Chemical composition of functionalized graphene with X ray photoelectron spectroscopy (XPS) N2 - The results of the interlaboratory comparison about the chemical composition of functionalized graphene are presented. T2 - DIN Meeting NA 062-08-16 AA CY - Berlin, Germany DA - 25.05.2023 KW - X-ray photoelectron spectroscopy KW - Functionalized graphene KW - Interlaboratory comparison KW - VAMAS PY - 2023 AN - OPUS4-57650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knigge, Xenia T1 - Characterization of sterilized nanoparticles by lab-based XPS and HAXPES N2 - The novel lab-based HAXPES spectrometer (ULVAC-PHI Quantes) gives us the possibility to measure XPS at 1486.6 eV (monochromatic Al Kα source) and HAXPES at 5414.9 eV (monochromatic Cr Kα source) on a sample at the same position. The surface analysis with this spectrometer leads to an information depth of about 10 nm for XPS and in comparison, to an analysis of deeper regions of about 30 nm for HAXPES measurements. This method provides a nondestructive way to distinguish between the near-surface region of the nanoparticles and the whole nanoparticle. Additionally, HAXPES gives access to deeper core levels at higher energy. An application of this technique is presented using nanoparticles. The results shown were obtained with nanoparticles, that were treated differently by means of sterilization for nanosafety (i.e., before studying their toxicity it is important to establish whether nanomaterials are sterile and, if not, to be treated either via microwave or autoclave sterilisation). As a complementary method, the data is compared with SEM and EDX measurements. All methods demonstrate the influence of sterilization. More specifically, these results show that the sterilization step must be considered in the physical-chemical description of the particles for establishing reliable (quantitative structure-activity) relationships. T2 - ECASIA 2022 CY - Limerick, Ireland DA - 29.05.2022 KW - XPS KW - HAXPES KW - Nanoparticles PY - 2022 AN - OPUS4-54968 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 Ce0.5Zr0.5O2 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterilized Ce0.5Zr0.5O2 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - XPS KW - HAXPES KW - SEM KW - NanoSolveIT KW - Ce0.5Zr0.5O2 nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7965445 PB - Zenodo CY - Geneva AN - OPUS4-57670 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 - 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 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Borghetti, P. A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Garcia, S. A1 - Gómez, E. A1 - Blanco, M. A1 - Alberto, G. A1 - Martra, G. T1 - Organic surface modification and analysis of titania nanoparticles for self‐assembly in multiple layers N2 - The characteristics of TiO2 coatings can greatly influence their final performance in large‐scale applications. In the present study, self‐assembly of TiO2 nanoparticles (NPs) in multiple layers was selected as a deposition procedure on various substrates. For this, the main prerequisite constitutes the surface modification of both NPs and substrate with, for example, silane coupling agents. A set of functionalized TiO2 NPs has been produced by reaction with either (3‐aminopropyl)triethoxysilane (APTES) or (3‐aminopropyl)phosphonic acid (APPA) to functionalize the NP surface with free amino‐groups. Then, the complementary functionalized NP set can be obtained from an aliquot of the first one, through the conversion of free surface amino groups to aldehydes by reaction with glutaraldehyde (GA). Several types of TiO2 NPs differing in size, shape, and specific surface area have been functionalized. Fourier‐transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), SEM/ energy‐dispersive X‐ray spectroscopy (EDS), XPS, Auger electron spectroscopy (AES), and Time‐of‐Flight (ToF)‐SIMS analyses have been carried out to evaluate the degree of functionalization, all the analytical methods employed demonstrating successful functionalization of TiO2 NP surface with APTES or APPA and GA. KW - TiO2 KW - Nanoparticles KW - Surface functionalization KW - Layer-by-layer deposition KW - Surface chemical analysis PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508601 DO - https://doi.org/10.1002/sia.6842 SN - 1096-9918 VL - 52 IS - 12 SP - 829 EP - 834 PB - John Wiley & Sons Ltd AN - OPUS4-50860 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Role of Sample Preparation for Accurate and Automated Morphological Analysis of Nanoparticles proven in Interlaboratory Comparison Exercises N2 - Traceable morphological and chemical characterization of nanomaterials with respect to the various possible sizes, size distributions, shapes, and concentrations of real-world nanoparticles (NPs) is a challenging task. Particularly for the nonspherical, non-monodisperse nanoparticles – as typically for most of the commercial particles, including their strong tendency to agglomerate, there is a lack of standard operation procedures providing accurate nanoparticle characterisation. In the framework of the pre-standardisation framework of VAMAS (Versailles Project on Advanced Materials and Standards, www.vamas.org) two interlaboratory comparison (ILC) studies are being carried out under the Technical Working Area (TWA) 34 “Nanoparticle Populations”:i) Project #15 addresses the analysis of the size and shape distribution of TiO2 bipyramidal NPs by traceable imaging methods such as TEM, SEM, STEM-in-SEM, AFM as well as with SAXS as an ensemble method. This ILC is thought as the next level development of the case studies exemplified in the published ISO standards ISO 21363 and ISO 19749. It was agreed to complete the first ILC with the NPs already prepared according to the same procedure on a TEM grid, and, at a later stage, to carry out second ILCs with the same NPs distributed to the participants as liquid suspensions together with protocols for the uniform NP deposition on suited substrates - as developed and optimized within the European project nPSize. Once having good deposition protocols available, the door for automated image analysis gets opened. Corresponding image analysis protocols and reporting templates have been distributed to the ILC participants, too. ii) Project #16: two spherical SiO2 NP samples with bi-modal size distributions in two nominal relative number concentrations were prepared and distributed also as liquid suspensions accompanied by sample preparation, measurement, and image analysis protocols and reporting templates. Here, the NP concentration is the primary parameter to be measured. For the imaging methods it is targeted to measure the relative nanoparticle concentrations (relative populations of the two modes). The results of all the participating laboratories, in both ILCs, compiled in comparative representations will be shown and discussed for the first time. The reduction of the measurement uncertainties associated to the size, shape and number-concentration results induced by the significant improvement of the sample preparation on substrates (as single particles with a high-density coverage), combined with welldefined image analysis procedures will be highlighted. T2 - MaterialsWeek 2024 CY - Limassol, Cyprus DA - 17.06.2024 KW - Nanoparticles KW - VAMAS KW - Interlaboratory comparison KW - Sample preparation KW - Nanoparticle concentration PY - 2024 AN - OPUS4-60453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul T1 - The Role of Electron Microscopy in the Development of Monodisperse Cubic Iron Oxide Nanoparticles as CRM for Size and Shape N2 - Due to their unique physico-chemical properties, nanoparticles are well established in research and industrial applications. A reliable characterization of their size, shape, and size distribution is not only mandatory to fully understand and exploit their potential and develop reproducible syntheses, but also to manage environmental and health risks related to their exposure and for regulatory requirements. To validate and standardize methods for the accurate and reliable particle size determination nanoscale reference materials (nanoRMs) are necessary. However, there is only a very small number of nanoRMs for particle size offered by key distributors such as the National Institute of Standards and Technology (NIST) and the Joint Research Centre (JRC) and, moreover, few provide certified values. In addition, these materials are currently restricted to polymers, silica, titanium dioxide, gold and silver, which have a spherical shape except for titania nanorods. To expand this list with other relevant nanomaterials of different shapes and elemental composition, that can be used for more than one sizing technique, we are 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 for the material and life sciences. T2 - Microscopy and Microanalysis 2022 CY - Online meeting DA - 31.07.2022 KW - Certified Referencematerial KW - Cubical Iron Oxide KW - Nanoparticles KW - Electron Microscopy KW - Small-Angle X-ray Scattering PY - 2022 AN - OPUS4-57035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cant, D. J. H. A1 - Minelli, C. A1 - Sparnacci, K. A1 - Müller, Anja A1 - Kalbe, H. A1 - Stoger-Pollach, M. A1 - Unger, Wolfgang A1 - Werner, W. S. M. A1 - Shard, A. G. T1 - Surface-Energy Control and Characterization of Nanoparticle Coatings N2 - Accurate and reproducible measurement of the structure and properties of high-value nanoparticles is extremely important for their commercialization. A significant proportion of engineered nanoparticle systems consist of some form of nominally core-shell structure, whether by design or unintentionally. Often, these do not form an ideal core-shell structure, with typical deviations including polydispersity of the core or shell, uneven or incomplete shells, noncentral cores, and others. Such systems may be created with or without intent, and in either case an understanding of the conditions for formation of such particles is desirable. Precise determination of the structure, composition, size, and shell thickness of such particles can prove challenging without the use of a suitable range of characterization techniques. Here, the authors present two such polymer core-shell nanoparticle systems, consisting of polytetrafluoroethylene cores coated with a range of thicknesses of either polymethylmethacrylate or polystyrene. By consideration of surface energy, it is shown that these particles are expected to possess distinctly differing coating structures, with the polystyrene coating being incomplete. A comprehensive characterization of these systems is demonstrated, using a selection of complementary techniques including scanning electron microscopy, scanning transmission electron microscopy, thermogravimetric analysis, dynamic light scattering, differential centrifugal sedimentation, and X-ray photoelectron spectroscopy. By combining the results provided by these techniques, it is possible to achieve superior characterization and understanding of the particle structure than could be obtained by considering results separately. KW - Nanoparticles KW - Core-shell KW - XPS KW - Size KW - Thickness KW - Damage PY - 2020 DO - https://doi.org/10.1021/acs.jpcc.0c02161 VL - 124 IS - 20 SP - 11200 EP - 11211 PB - ACS CY - Washington DC AN - OPUS4-50899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Analysis of Particle Size Distribution for Bimodal Model Nanoparticles by Scanning Electron Microscopy N2 - The present study addresses the capability of measurement of relative particle number concentration by scanning electron microscopy for model bimodal silica and gold samples prepared in the frame of the European research project “nPSize - Improved traceability chain of nanoparticle size measurements” as candidate reference nanoparticles. T2 - Microscopy and Microanalysis 2020 CY - Online meeting DA - 03.08.2020 KW - Nanoparticles KW - Silica KW - Gold KW - Electron microscopy KW - Particle size distribution PY - 2020 AN - OPUS4-51112 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 - 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 - JOUR A1 - Müller, Anja A1 - Sparnacci, K. A1 - Unger, Wolfgang A1 - Tougaard, S. T1 - Determining nonuniformities of core-shell nanoparticle coatings by analysis of the inelastic background of X-ray photoelectron spectroscopy survey spectra N2 - Most real core-shell nanoparticle (CSNP) samples deviate from an ideal core-shell structure potentially having significant impact on the particle properties. An ideal structure displays a spherical core fully encapsulated by a shell of homogeneous thickness, and all particles in the sample exhibit the same shell thickness. Therefore, analytical techniques are required that can identify and characterize such deviations. This study demonstrates that by analysis of the inelastic background in X-ray photoelectron spectroscopy (XPS) survey spectra, the following types of deviations can be identified and quantified: the nonuniformity of the shell thickness within a nanoparticle sample and the incomplete encapsulation of the cores by the shell material. Furthermore, CSNP shell thicknesses and relative coverages can be obtained. These results allow for a quick and straightforward comparison between several batches of a specific CSNP, different coating approaches, and so forth. The presented XPS methodology requires a submonolayer distribution of CSNPs on a substrate. Poly(tetrafluoroethylene)-poly(methyl methacrylate) and poly(tetrafluoroethylene)-polystyrene polymer CSNPs serve as model systems to demonstrate the applicability of the approach. KW - Core-shell KW - Nanoparticles KW - Inelastic background KW - Polymers KW - QUASES KW - XPS PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511315 DO - https://doi.org/10.1002/sia.6865 SN - 0142-2421 SN - 1096-9918 VL - 52 SP - 1 EP - 8 PB - Wiley CY - Chichester AN - OPUS4-51131 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 - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of sterilized Ce0.75Zr0.25O2 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterilized Ce0.75Zr0.25O2 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - XPS KW - HAXPES KW - SEM KW - NanoSolveIT KW - Ce0.75Zr0.25O2 nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7966133 PB - Zenodo CY - Geneva AN - OPUS4-57673 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 Ce0.1Zr0.9O2 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterilized Ce0.1Zr0.9O2 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - XPS KW - HAXPES KW - SEM KW - NanoSolveIT KW - Ce0.1Zr0.9O2 nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7965602 PB - Zenodo CY - Geneva AN - OPUS4-57672 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 Co3O4 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterilized Co3O4 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - XPS KW - HAXPES KW - SEM KW - NanoSolveIT KW - Co3O4 nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7941248 PB - Zenodo CY - Geneva AN - OPUS4-57666 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 ZrO2 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterilized ZrO2 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - XPS KW - HAXPES KW - SEM KW - NanoSolveIT KW - ZrO2 nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7965536 PB - Zenodo CY - Geneva AN - OPUS4-57671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sachse, René A1 - Pfüger, Mika A1 - Velasco-Vélez, Juan-Jesús A1 - Sahre, Mario A1 - Radnik, Jörg A1 - Bernicke, Michael A1 - Bernsmeier, Denis A1 - Hodoroaba, Vasile-Dan A1 - Krumrey, Michael A1 - Strasser, Peter A1 - Kraehnert, Ralph A1 - Hertwig, Andreas T1 - Assessing optical and electrical properties of highly active IrOx catalysts for the electrochemical oxygen evolution reaction via spectroscopic ellipsometry N2 - Efficient water electrolysis requires highly active electrodes. The activity of corresponding catalytic coatings strongly depends on material properties such as film thickness, crystallinity, electrical conductivity, and chemical surface speciation. Measuring these properties with high accuracy in vacuum-free and nondestructive methods facilitates the elucidation of structure−activity relationships in realistic environments. Here, we report a novel approach to analyze the optical and electrical properties of highly active oxygen evolution reaction (OER) catalysts via spectroscopic ellipsometry (SE). Using a series of differently calcined, mesoporous, templated iridium oxide films as an example, we assess the film thickness, porosity, electrical resistivity, electron concentration, electron mobility, and interband and intraband transition energies by modeling of the optical spectra. Independently performed analyses using scanning electron microscopy, energy-dispersive X-ray spectroscopy, ellipsometric porosimetry, X-ray reflectometry, and absorption spectroscopy indicate a high accuracy of the deduced material properties. A comparison of the derived analytical data from SE, resonant photoemission spectroscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy with activity measurements of the OER suggests that the intrinsic activity of iridium oxides scales with a shift of the Ir 5d t2g sub-level and an increase of p−d interband transition energies caused by a transition of μ1-OH to μ3-O species. KW - Spectroscopic ellipsometry KW - Electrocatalysis KW - Oxygen evolution reaction KW - Mesoporous iridium oxide films KW - Non-destructive ambient analysis KW - Intrinsic OER activity KW - Complementary methodology and metrology PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516288 DO - https://doi.org/10.1021/acscatal.0c03800 SN - 2155-5435 VL - 10 IS - 23 SP - 14210 EP - 14223 PB - American Chemical Society AN - OPUS4-51628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - EMPIR nPSize - Improved Traceability Chain of Nanoparticle Size Measurement N2 - In order to assess new nanomaterials and nanoparticles for potential risks to health and the environment, they need to be well-characterised. The measurement of constituent nanoparticle size, shape, and size distribution are important factors for the risk evaluation process. EMPIR project Improved traceability chain of nanoparticle size measurements (17NRM04, nPSize) is working to assess a range of traceable nanoparticle measurement approaches, including Electron Microscopy (SEM, TEM, STEM-in-SEM), Atomic Force Microscopy and Small Angle X-ray Scattering, and deliver improved calibration methods to users. For the techniques under investigation, physical models of their response to a range of nanoparticle types are developed. Validated reference materials are also used for inter-comparisons of measurement systems, with an evaluation of the associated measurement uncertainty. With project contributions to standards development work, manufacturers will be better placed to assess the human and environmental risks posed by nanomaterials across a whole range of products. T2 - EMPIR nPSize Training Course "Traceable Characterization of Nanoparticles by SAXS" CY - Online meeting DA - 01.02.2021 KW - Nanoparticles KW - Particle size distribution KW - Traceability KW - nPSize KW - SAXS PY - 2021 AN - OPUS4-53883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, Heike A1 - Knigge, Xenia A1 - Knapic, D. A1 - Weise, Matthias A1 - Sahre, Mario A1 - Hertwig, Andreas A1 - Sacco, A. A1 - Rossi, A. M. A1 - Radnik, Jörg A1 - Müller, Kai A1 - Wasmuth, Karsten A1 - Krüger, Jörg A1 - Hassel, A. W. A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Picosecond laser processing of hierarchical micro–nanostructures on titanium alloy upon pre- and postanodization: morphological, structural, and chemical effects N2 - Recent publications indicate that the order of electrochemical anodization (before or after the laser processing step) plays an important role for the response of bone-forming osteoblasts—an effect that can be utilized for improving permanent dental or removable bone implants. For exploring these different surface functionalities, multimethod morphological, structural, and chemical characterizations are performed in combination with electrochemical pre- and postanodization for two different characteristic microspikes covered by nanometric laser-induced periodic surface structures on Ti–6Al–4V upon irradiation with near-infrared ps-laser pulses (1030 nm wavelength, ≈1 ps pulse duration, 67 and 80 kHz pulse repetition frequency) at two distinct sets of laser fluence and beam scanning parameters. This work involves morphological and topographical investigations by scanning electron microscopy and white light interference microscopy, structural material examinations via X-ray diffraction, and micro-Raman spectroscopy, as well as near-surface chemical analyses by X-ray photoelectron spectroscopy and hard X-ray photoelectron spectroscopy. The results allow to qualify the mean laser ablation depth, assess the spike geometry and surface roughness parameters, and provide new detailed insights into the near-surface oxidation that may affect the different cell growth behavior for pre- or postanodized medical implants. T2 - 2023 E-MRS Spring Meeting, Symposium L "Making light matter: lasers in material sciences and photonics" CY - Strasbourg, France DA - 29.05.2023 KW - Hierarchical micro-nanostructures KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Ti-6Al-4V alloy KW - X-ray photoelectron spectroscopy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601962 DO - https://doi.org/10.1002/pssa.202300920 SN - 1862-6319 SP - 1 EP - 11 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-60196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bennet, Francesca T1 - Microprinting and SEM analysis for quantitative evaluation of nanoparticles in solution N2 - Nanoparticle suspensions were microprinted onto TEM grids for subsequent analysis by SEM/TSEM and evaluation of particle numbers using Image J software. Various nanoparticle types, concentrations and printing conditions (temperature, rel. humidity) were evaluated in order to determine the optimal conditions for producing a uniform distribution of particles on the substrate and eliminating the coffee ring effect. T2 - H2020 ACEnano Project Meeting CY - Amsterdam, Netherlands DA - 04.03.2020 KW - Nanoparticle KW - Imaging KW - Microprinting KW - Homogeneous deposition PY - 2020 AN - OPUS4-50584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cant, D. J. H. A1 - Müller, Anja A1 - Clifford, C. A. A1 - Unger, Wolfgang A1 - Shard, A. G. T1 - Summary of ISO/TC 201 Technical Report 23173—Surface chemical analysis—Electron spectroscopies—Measurement of the thickness and composition of nanoparticle coatings N2 - ISO Technical Report 23173 describes methods by which electron spectroscopies, including X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and synchrotron techniques, can be employed to calculate the Coating thicknesses and compositions of nanoparticles. The document has been developed to review and outline the current state-of-the-art for such measurements. Such analyses of core–shell nanoparticles are common within the literature, however the methods employed are varied; the relative advantages and disadvantages of These methods, and the optimal usage of each may not be clear to the general analyst. ISO Technical Report 23173 aims to clarify the methods that are available, describe them in clear terms, exhibit examples of their use, and highlight potential issues users may face. The information provided should allow analysts of electron spectroscopy data to make clear choices regarding the appropriate analysis of electron spectroscopy data from coated nanoparticle systems and provide a basis for understanding and comparing results from different methods and systems. KW - Electron spectroscopy KW - Core-shell KW - Nanoparticles KW - ISO 23173 KW - XPS KW - Thickness KW - Composition PY - 2021 DO - https://doi.org/10.1002/sia.6987 SN - 0142-2421 VL - 53 IS - 10 SP - 893 EP - 899 PB - John Wiley & Sons Ltd AN - OPUS4-52976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN ED - Hodoroaba, Vasile-Dan ED - Unger, Wolfgang ED - Shard, A. G. T1 - Characterization of nanoparticles - Measurement processes for nanoparticles N2 - Characterization of Nanoparticles: Measurement Processes for Nanoparticles surveys this fast growing field, including established methods for the physical and chemical characterization of nanoparticles. The book focuses on sample preparation issues (including potential pitfalls), with measurement procedures described in detail. In addition, the book explores data reduction, including the quantitative evaluation of the final result and its uncertainty of measurement. The results of published inter-laboratory comparisons are referred to, along with the availability of reference materials necessary for instrument calibration and method validation. The application of these methods are illustrated with practical examples on what is routine and what remains a challenge. In addition, this book summarizes promising methods still under development and analyzes the need for complementary methods to enhance the quality of nanoparticle characterization with solutions already in operation. KW - Nanoparticles KW - Characterization method KW - Sample preparation KW - Inter-laboratory comparison KW - Standardisation KW - Measurement uncertainty KW - Case studies PY - 2020 SN - 978-0-12-814182-3 DO - https://doi.org/10.1016/C2017-0-00312-9 SP - 1 EP - 566 PB - Elsevier CY - Amsterdam AN - OPUS4-50284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, P. M. A1 - Kjærvik, Marit A1 - Willneff, E. A. A1 - Unger, Wolfgang T1 - In-depth analysis of iodine in artificial biofilm model layers by variable excitation energy XPS and argon gas cluster ion sputtering XPS N2 - Here, we present a study on agarose thin-film samples that represent a model system for the exopolysaccharide matrix of biofilms. Povidone-iodide (PVP-I) was selected as an antibacterial agent to evaluate our x-ray photoelectron spectroscopy (XPS)-based methodology to trace specific marker elements, here iodine, commonly found in organic matrices of antibiotics. The in-depth distribution of iodine was determined by XPS analyses with variable excitation energies and in combination with argon gas cluster ion beam sputter cycles. On mixed agarose/PVP-I nanometer-thin films, both methods were found to solve the analytical task and deliver independently comparable results. In the mixed agarose/PVP-I thin film, we found the outermost surface layer depleted in iodine, whereas the iodine is homogeneously distributed in the depth region between this outermost surface layer and the interface between the thin film and the substrate. Depletion of iodine from the uppermost surface in the thin-film samples is assumed to be caused by ultrahigh vacuum exposure resulting in a loss of molecular iodine (I2) as reported earlier for other iodine-doped polymers. KW - Biofilm KW - XPS KW - Argon gas cluster ion sputtering KW - Variable excitation KW - Iodine PY - 2022 DO - https://doi.org/10.1116/6.0001812 SN - 1934-8630 VL - 17 IS - 3 SP - 1 EP - 8 PB - AVS AN - OPUS4-54973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mezera, Marek T1 - Influence of the pulse repetition rate on the chemical and morphological properties of laser generated surface structures N2 - Inter-pulse accumulation of heat could affect the chemical and morphological properties of the laser processed material surface. Hence, the laser pulse repetition rate may restrict the processing parameters for specific laser-induced surface structures. In this study, the evolution of various types of laser-induced micro- and nanostructures at various laser fluence levels, effective number of pulses and at different pulse repetition rates (1 – 400 kHz) are studied for common metals/alloys (e.g. steel or titanium alloy) irradiated by near-infrared ultrashort laser pulses (925 fs, 1030 nm) in air environment. The processed surfaces were characterized by optical and scanning electron microscopy (OM, SEM), energy dispersive X-ray spectroscopy (EDX) as well as time of flight secondary ion mass spectrometry (TOF-SIMS). The results show that not only the surface morphology could change at different laser pulse repetition rates and comparable laser fluence levels and effective number of pulses, but also the surface chemistry is altered. Consequences for medical applications are outlined. T2 - European Materials Research Society Spring 2021 Meeting CY - Online meeting DA - 31.05.2021 KW - Laser-induced pariodic surface structures KW - LIPSS PY - 2021 AN - OPUS4-52778 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pellegrino, F. A1 - Sordello, F. A1 - Mino, L. A1 - Prozzi, M. A1 - Mansfeld, Ulrich A1 - Hodoroaba, Vasile-Dan A1 - Minero, C. T1 - Polyethylene Glycol as Shape and Size Controller for the Hydrothermal Synthesis of SrTiO3 Cubes and Polyhedra N2 - Understanding the correlation between the morphological and functional properties of particulate materials is crucial across all fields of physical and natural sciences. This manuscript reports on the investigation of the effect of polyethylene glycol (PEG) employed as a capping Agent in the synthesis of SrTiO3 crystals. The crucial influence of PEG on both the shape and size of the strontium titanate particles is revealed, highlighting the effect on the photocurrents measured under UV–Vis irradiation. KW - Polyethylene glycol KW - Strontium titanate KW - Controlled morphology KW - Photoelectrochemistry KW - Electron microscopy KW - EDS PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512892 DO - https://doi.org/10.3390/nano10091892 VL - 10 IS - 9 SP - 1892 PB - MDPI CY - Basel, CH AN - OPUS4-51289 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 - CONF A1 - Marcoulaki, E. T1 - Blueprint for a sustainable new European Centre to support safe innovation for nanotechnology N2 - This paper presents the blueprint for the operation of a sustainable and permanent European Centre of collaborating reference laboratories and research centres, to establish a one-stop shop for a wide variety of nanosafety related services, and to provide a central contact point for questions about nanosafety in Europe. The Centre aims to harmonise service provision, and bring novel risk assessment and management approaches closer to practice. T2 - NANOSAFE 2020 CY - Online meeting DA - 16.11.2020 KW - EC4SafeNano KW - European Centre KW - Nanomaterials KW - Nanosafety KW - Catalogue of Services (CoS) PY - 2020 UR - https://www.nanosafe.org/cea-tech/pns/nanosafe/en AN - OPUS4-51694 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 - Mirabella, Francesca T1 - ToF-SIMS as a new tool for nano-scale investigation of ps-laser-generated surface structures on titanium substrates N2 - In recent years, the fabrication of laser-generated surface structures on metals such as titanium surfaces have gained remarkable interests, being technologically relevant for applications in optics, medicine, fluid transport, tribology, and wetting of surfaces. The morphology of these structures, and so their chemistry, is influenced by the different laser processing parameters such as the laser fluence, wavelength, pulse repetition rate, laser light polarization type and direction, angle of incidence, and the effective number of laser pulses per beam spot area. However, the characterization of the different surface structures can be difficult because of constraints regarding the analytical information from both depth and the topographic artifacts which may limit the lateral and depth resolution of elemental distributions as well as their proper quantification. A promising technique to investigate these structures even at the nano-scale is Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), a very surface sensitive technique that at the same time allows to perform depth-profiling, imaging and 3D-reconstruction of selected ion-sputter fragment distributions on the surface. In this study we combine chemical analyses such as Energy Dispersive X-ray spectroscopy (EDX) and high-resolution scanning electron microscopy (SEM) analyses with ToF-SIMS to fully characterize the evolution of various types of laser-generated micro- and nanostructures formed on Ti and Ti alloys at different laser fluence levels, effective number of pulses and at different pulse repetition rates (1 – 400 kHz), following irradiation by near-infrared ultrashort laser pulses (925 fs, 1030 nm) in air environment or under argon gas flow. We show how this combined surface analytical approach allows to evaluate alteration in the surface chemistry of the laser-generated surface structures depending on the laser processing parameters and the ambient environment. T2 - European Materials Research Society (EMRS) Fall Meeting 2021 CY - Online meeting DA - 20.09.2021 KW - ToF SIMS KW - Nano characterization PY - 2021 AN - OPUS4-53366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Morphological and Chemical Nanoscale Analysis of Mesoporous Mixed IrO x TiO y Thin Films as Electrode Materials N2 - Porous films play an important role particularly in energy applications like photovoltaics, electrolysis or batteries. Thin film properties such as thickness, chemical composition, crystallinity of the framework, and porosity define the activity of the porous films. The accurate morpho-chemical characterisation of mesoporous thin films is a challenging analytical task which requires the consideration of new analytical approaches based on the combination of data of different methods able to address the structure and chemical composition at the nanoscale. In this contribution we characterise thin mesoporous iridium-titanium mixed oxide film properties by Electron Probe Microanalysis (EPMA) with Energy-Dispersive X-ray Spectroscopy (EDS) at an SEM applied in a dedicated “thin film analysis” approach (1). Thus, the film mass deposition, film thickness and the film density can be determined. Further, by dividing the measured film density to an assumed (theoretical) metal oxide framework (skeletal) density, the thin film porosity can be extracted, too. In order to assess the homogeneity of the thin film properties like the chemical composition, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Auger Electron Spectrometry are applied in the depth profiling mode, so that possible in-depth gradients are detected. Lateral inhomogeneities in the chemical composition and structure of the thin mesoporous films are also identified by applying the same methods in the line-scan or mapping mode, which can be further combined with in-depth sputtering for 3D information. The role of the spatial resolution of the analytical methods considered, which can go down well below 100 nm, will be highlighted. T2 - Microscopy and Microanalysis 2024 CY - Cleveland, OH, USA DA - 28.07.2024 KW - Auger electron spectroscopy KW - Iridium oxide KW - Mesoporous thin films KW - SIMS KW - Titanium oxide KW - Porosity PY - 2024 AN - OPUS4-60805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -