TY - JOUR A1 - Arinchtein, A. A1 - Ye, M.-Y. A1 - Yang, Q. A1 - Kreyenschulte, C. A1 - Wagner, Andreas A1 - Frisch, M. A1 - Brückner, A. A1 - Kondratenko, E. A1 - Kraehnert, R. T1 - Dynamics of Reaction-Induced Changes of Model-Type Iron Oxide Phases in the CO2-Fischer-Tropsch-Synthesis N2 - Iron-based catalysts are employed in CO2-FTS due to their ability to convert CO2 into CO in a first step and their selectivity towards higher hydrocarbons in a second CO hydrogenation step. According to the literature, iron carbides represent the active phase for hydrocarbon formation and are claimed to emerge in the presence of CO. We propose nanostructured FeOx films as model systems to assess information about the complex phase transformations during CO2-FTS. Mesoporous hematite, ferrihydrite, maghemite, maghemite/magnetite films were exposed to CO2-FTS atmospheres at 20 bar and 300°C. Up to three distinct phases were observed depending on the timeon-stream (TOS): a sintered maghemite/magnetite phase, a carbidic core-shell structure, and a low-crystalline, needle-type oxide phase. Our findings indicate that the formation of an intermediary maghemite/magnetite phase, predominant after short TOS (30 h), precedes the evolution of the carbide phase. Yet, even after prolonged TOS (185 h), no full conversion into a bulk carbide is observed. KW - Nanostructured FeOx films KW - CO2 KW - Scanning Auger Spectroscopy PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549709 DO - https://doi.org/10.1002/cctc.202200240 SN - 1867-3880 VL - 14 IS - 14 SP - 1 EP - 11 PB - Wiley-VCH AN - OPUS4-54970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Nirmalananthan-Budau, Nithiya A1 - Tavernaro, Isabella T1 - Engineered Nanomaterials- Novel Approaches for Risk Assessment and Safe-by-Design N2 - The overall interest in nanotoxicity, triggered by the increasing use of nanomaterials in the material and life sciences, and the synthesis of an ever increasing number of new functional nanoparticles calls not only for standardized test procedures1,2 and for efficient approaches to screen the potential genotoxicity of these materials, but also for standardized and validated methods for surface analysis. 4,5 The analysis and quantification of surface chemistry is hence in the focus of an increasing number of standardization organizations and interlaboratory comparisons with different analytical methods are being done.5 For the monitoring of nanomaterial synthesis and the fast assessment of the number of functional groups such as carboxyl and amino functionalities, which are very commonly used functionalities in the life sciences, simple and validated methods are needed that can be performed with common laboratory instrumentation. 5,6 Here we provide a brief overview of the ongoing research in division Biophotonics employing quantitative NMR (qNMR), conductometry, and colorimetric and fluorometric optical assays for the determination of the total and the accessible number of carboxyl and amino groups on differently sized polymer and silica nano- and microparticles.5-7 T2 - Workshop NanoRiskSD project CY - Berlin, Germany DA - 09.06.2022 KW - Nanoparticle KW - Surface analysis KW - Standardization KW - Quality assurance KW - Validation KW - qNMR KW - Silica KW - Polymer KW - Fluorescence KW - Assay KW - Conductometry KW - Method comparison KW - Analytical sciences PY - 2022 AN - OPUS4-54999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Chaudhary, A. A1 - Resch-Genger, Ute T1 - Development of amorphous silica particle based reference materials for surface functional group quantification N2 - Functionalized nanomaterials (NM) with their unique size-dependent properties are of increasing relevance for current and future developments in various fields such as medical and pharmaceutical industry, computing, electronics or food and consumer products. The performance and safety of NM are determined by the sum of their intrinsic physicochemical properties.1 Besides other key parameters, the particle surface chemistry, which is largely controlled by the chemical nature and density of functional groups and ligands, must be considered for a better performance, stability, and processibility of NM, as well as their interaction with the environment. Thus, particle standards with well-designed surfaces and methods for functional group quantification can foster the sustainable development of functional and safe(r) NM.2 Here we provide a brief overview of the ongoing research in division Biophotonics to design tailored amorphous silica reference particles with bioanalytically relevant functional groups and ligands, for the development of standardized and validated surface functional group quantification methods. T2 - Workshop NanoRiskSD project CY - Berlin, Germany DA - 09.06.2022 KW - Nanoparticle KW - Surface analysis KW - Silica KW - Fluorescence KW - Assay PY - 2022 AN - OPUS4-55004 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolmangadi, Mohamed Aejaz A1 - Schönhals, Andreas T1 - Side Chain length dependent dynamics and conductivity of Ionic Liquid crystals N2 - We investigate the molecular dynamics and electrical conductivity for a homologous series of linear shaped guanidinium based cyclic ILCs that vary in alkyl chain length, CLCRs (R = 8, 10, 12, 14, 16) by employing broadband dielectric spectroscopy (BDS), and calorimetry comprised of Fast Scanning Calorimetry (FSC) and temperature modulated FSC (TMFSC). Besides conductivity at high temperatures, the dielectric dispersion reveals two relaxation modes: the fast γ and the slow α1 relaxation. The former is assigned to the localized fluctuations while the latter is due to segmental dynamics of the alkyl chains. The γ mode slows down for long chain length CLCs (12,14,16) compared to their shorter analogues. Calorimetric investigation reveals one process, the α2 process, for all ILCs. The α2 process for CLC10, 12, and 14 has a similar temperature dependence as the dielectric α1 relaxation, while for the CLC8 and 10, it's shifted to a higher temperature. For all CLCRs, the absolute values of DC conductivity increase by 4 orders of magnitude at the transition from the plastic crystalline to hexagonal columnar phase. This increase is due to the change in the underlying conduction mechanism from delocalized electron hopping in the crystalline phase to one-dimensional ion mobility in the columnar phase. The glassy dynamics shifts to higher temperatures with increasing alkyl chain length. Conversely, the DC conductivity drops by 3 orders of magnitude from CLC8 to CLC16. T2 - APS March Meeting 2022 CY - Chicago, IL, USA DA - 13.03.2022 KW - Glass transition KW - Conductivity KW - Fast Scanning Calorimetry KW - Dynamics PY - 2022 AN - OPUS4-54760 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 - What nPSize can offer to ISO/TC 229? N2 - The main outcomes of the EMPIR project nPSize are presented and the suitability of the new capabilities, e.g. reference materials, sample preparation protocols, measurement procedures, and data analysis, to be standardized and implemented in accredited analytical laboratories is discussed. Complementation and/or filling gaps of published and ongoing standardisation projects on size, shape and number concentration measurements under ISO/TC 229/JWG 2 are offered. The two VAMAS inter-laboratory comparisons resulted from the nSPize project and just started under TWA 34 Nanoparticle Populations (Projects #15 and #16) of bipyramidal TiO2 anatase and bimodal SiO2 nanoparticles are presented in detail. T2 - Interim Meeting of ISO/TC 229 Nanotechnologies - Strategy and Metrology Group CY - Online meeting DA - 09.05.2022 KW - Nanoparticles KW - Particle size distribution KW - Inter-laboratory comparison KW - Electron microscopy KW - AFM KW - SAXS KW - ISO/TC229 PY - 2022 AN - OPUS4-54819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Advanced Characterization of the Surface Morphology and Chemistry within nano@BAM N2 - Both essential aspects of the surface of solid matter, its morphology and chemistry, are studied traditionally at BAM starting in the 60’s with different cyclical research focus areas, mostly related either to applicative research or method development. In the recent years, the focus has shifted almost exclusively to the nano-analytics of advanced materials such as complex nanoparticles, (ultra)thin films/coatings, nanocomposites, 2D materials, energy materials, etc. This is also the reason why BAM has established recently the new Competence Center nano@BAM (www.bam.de/Navigation/DE/Themen/Material/Nanotechnologie/sichere-nanomaterialien.html) with the five sub-fields nanoCharacterisation, nanoMaterial, nanoSafety, nanoData and nanoTechnology. The link to the BAM central guidelines to the safety in technology and chemistry is given by the development of reference products such as reference measurement procedures, reference (nano)materials, and newly reference data sets. Thus, an internationally well-networked group in surface analysis has been established @BAM, with regular contributions to integral analytical characterization with metrological and standardization background. Examples of newly developed methodical approaches will be given with an emphasis on correlative nano-analysis of morphology and chemistry of nanomaterials. Correlative imaging by STEM-in-SEM with high-resolution SEM and EDX, and further with AFM or the new technique TKD (Transmission Kikuchi Diffraction) will be explained on various examples of nanostructures, both as starting materials and embedded/functionalized nanoparticles in products. The unique analytical benefits of the Auger electron probe as a veritable nano-tool for surface chemistry will be highlighted. The panoply of advanced surface characterization methods @BAM is completed by discussing examples of hybrid analysis of the bulk of nanomaterials by X-ray Spectroscopy with the highest surface-sensitive methods X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). Particularly for the analysis of the surface chemistry of nanostructures, such as the completeness of the shells of core-shell nanoparticles or in-depth and lateral gradients of chemistry within mesoporous thin layers, the latter methods are inherent. Other special developments like approaches for the quantitative determination of the roughness of particle surface by electron microscopy or for the quantitative determination of the porosity of thin mesoporous layers by electron probe microanalysis (EPMA) with SEM will be presented. T2 - Seminar of the Academic Centre for Materials and Nanotechnology CY - Online meeting DA - 12.05.2022 KW - Nanoparticles KW - Thin films KW - Nano Characterisation KW - Nanomaterials KW - Surface morphology KW - Surface chemistry PY - 2022 UR - https://www.agh.edu.pl/en/info/article/seminar-advanced-characterization-of-the-surface-morphology-and-chemistry-within-nanobam/ AN - OPUS4-54820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Frenzel, Florian A1 - Würth, Christian A1 - Grauel, Bettina A1 - Hirsch, T. A1 - Haase, M. T1 - Measuring the Upconversion Luminescence of Ensemble and Single Particle Lanthanide-Based Upconversion Nanocrystals N2 - Lanthanide-based upconversion nanoparticles (UCNPs) like hexagonal 𝛽-NaYF4 UCNPs doped with Yb3+ and Er3+, which efficiently convert 976 nm light to ultraviolet, visible, and near infrared photons, offer new strategies for luminescence-based sensing, barcoding, and Imaging. Their upconversion (UC) luminescence (UCL) features like UCL intensity, quantum yield, relative spectral distribution / UCL luminescence color, and luminescence decay kinetics are, however, strongly influenced by particle size, dopant ion concentration, particle architecture, surface chemistry including presence and thickness of surface passivation and shielding shells, microenvironment/presence of quenchers with high energy vibrations, and excitation power density (P). We present here a comprehensive study of the influence of excitation power density on the UCL features of different types of UCNPs, focusing on Yb3+ and Er3+ co-doped NaYF4 core-only and core-shell nanostructures with different sizes and doping ion concentration, which underlines the importance of P-dependent optimum dopant concentrations for UCNP performance and the potential of P-tuning of UCL. T2 - Materials Challenges in Alternative & Renewable Energy 2021 (MCARE 2021) CY - Online meeting DA - 19.07.2021 KW - Fluorescence KW - Lifetime KW - Method KW - Stability KW - Coating KW - Surface chemistry KW - Lanthanide KW - Upconversion KW - Nano KW - Particle KW - Single particle spectroscopy KW - Quantum yield KW - Microscopy KW - Photophysics PY - 2021 AN - OPUS4-53111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Hörenz, Christoph A1 - Pellegrino, F. A1 - Maurino, V. A1 - Durande, B. A1 - Taché, O. T1 - Nanoparticle size, shape, and concentration measurement at once – two VAMAS pre-standardization projects ready to start N2 - A case study on the TEM analysis of the size and shape distribution of TiO2 bipyramidal nanoparticles prepared on TEM grids was included in the recently published ISO standard ISO 21363. It was agreed to organize at a later stage a second inter-lab comparison with the nanoparticles distributed to the participants as a liquid suspension. Protocols for uniform nanoparticle deposition on suited supports developed and optimized within the EMPIR nPSize project are also prepared to be distributed. For this, we have chosen the VAMAS platform (www.vamas.org) which offers an excellent international infrastructure of laboratories with high competence in nanoparticle measurement. The VAMAS technical working area dedicated to nanoparticle measurement is TWA 34 ‘Nanoparticle populations’. For this type of nanoparticles, the size and shape distributions are the primary parameters to be reported. Due to the good deposition protocols developed, an automated image analysis is enabled (in contrast to the manual analysis of irregular TiO2 nanoparticles. In parallel with the TiO2 nanoparticle exercise, two spherical SiO2 nanoparticle samples with bi-modal size distributions (nominal relative number concentrations of 1:1 and 10:1) are prepared for a second VAMAS inter-lab comparison. Here, the nanoparticle concentration is the primary parameter to be measured. For the imaging methods it is targeted to measure the relative nanoparticle concentrations of the two modes. For the absolute nanoparticle concentration to be measured by imaging methods it is necessary to control the volume of the liquid suspension deposited on the substrate and to obtain such a homogeneous nanoparticle deposition on the substrate which allows to count (or extrapolate) all the deposited particles. T2 - Microscopy and Microanalysis 2021 CY - Online meeting DA - 01.08.2021 KW - Nanoparticles KW - Electron microscopy KW - VAMAS KW - Inter-laboratory comparison KW - TiO2 KW - SiO2 PY - 2021 AN - OPUS4-53065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Busch, R. A1 - Tielemann, Christopher A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Patzig, C. A1 - Krause, M. A1 - Höche, T. T1 - Sample preparation for analytical scanning electron microscopy using initial notch sectioning N2 - A novel method for broad ion beam based sample sectioning using the concept of initial notches is presented. An adapted sample geometry is utilized in order to create terraces with a well-define d step in erosion depth from the surface. The method consists of milling a notch into the surface, followed by glancing-angle ion beam erosion, which leads to preferential erosion at the notch due to increased local surface elevation. The process of terrace formation can be utilized in sample preparation for analytical scanning electron microscopy in order to get efficient access to the depth-dependent microstructure of a material. It is demonstrated that the method can be applied to both conducting and non-conducting specimens. Furthermore, experimental parameters influencing the preparation success are determined. Finally, as a proof-of-concept, an electron backscatter diffraction study on a surface crystallized diopside glass ceramic is performed, where the method is used to analyze orientation dependent crystal growth phenomena occurring during growth of surface crystals into the bulk. KW - 3D etching KW - Ion beam erosion Sectioning KW - EBSD KW - Sample preparation KW - Analytical scanning electron microscopy KW - SEM KW - Glass Ceramic KW - Glass KW - Diopsid PY - 2021 DO - https://doi.org/10.1016/j.micron.2021.103090 SN - 0968-4328 VL - 150 PB - Elsevier B.V. AN - OPUS4-53075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Hörenz, Christoph A1 - Pellegrino, F. A1 - Maurino, V. A1 - Durand, B. A1 - Taché, O. T1 - Nanoparticle size, shape, and concentration measurement at once – two VAMAS pre-standardization projects ready to start N2 - A case study on the TEM analysis of the size and shape distribution of TiO2 bipyramidal nanoparticles prepared on TEM grids was included in the recently published ISO standard ISO 21363. It was agreed to organize at a later stage a second inter-lab comparison with the nanoparticles distributed to the participants as a liquid suspension. Protocols for uniform nanoparticle deposition on suited supports developed and optimized within the EMPIR nPSize project are also prepared to be distributed. For this, we have chosen the VAMAS platform (www.vamas.org) which offers an excellent international infrastructure of laboratories with high competence in nanoparticle measurement. The VAMAS technical working area dedicated to nanoparticle measurement is TWA 34 ‘Nanoparticle populations’. For this type of nanoparticles, the size and shape distributions are the primary parameters to be reported. Due to the good deposition protocols developed, an automated image analysis is enabled (in contrast to the manual analysis of irregular TiO2 nanoparticles. In parallel with the TiO2 nanoparticle exercise, two spherical SiO2 nanoparticle samples with bi-modal size distributions (nominal relative number concentrations of 1:1 and 10:1) are prepared for a second VAMAS inter-lab comparison. Here, the nanoparticle concentration is the primary parameter to be measured. For the imaging methods it is targeted to measure the relative nanoparticle concentrations of the two modes. For the absolute nanoparticle concentration to be measured by imaging methods it is necessary to control the volume of the liquid suspension deposited on the substrate and to obtain such a homogeneous nanoparticle deposition on the substrate which allows to count (or extrapolate) all the deposited particles. KW - Electron microscopy KW - Inter-laboratory comparison KW - Nanoparticles KW - SiO2 KW - TiO2 KW - VAMAS PY - 2021 DO - https://doi.org/10.1017/S1431927621008126 VL - 27 IS - Suppl. 1 SP - 2250 EP - 2251 PB - Cambridge University Press AN - OPUS4-53124 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Przyklenk, A. A1 - Balsamo, A. A1 - O'Connor, D. A1 - Evans, Alexander A1 - Yandayan, T. A1 - Akgöz, S. A1 - Flys, O. A1 - Zeleny, V. A1 - Czułek, D. A1 - Meli, F. A1 - Ragusa, C. A1 - Bosse, H. T1 - New European Metrology Network for advanced manufacturing N2 - Advanced manufacturing has been identified as one of the key enabling technologies with applications in multiple industries. The growing importance of advanced manufacturing is reflected by an increased number of publications on this topic in recent years. Advanced manufacturing requires new and enhanced metrology methods to assure the quality of manufacturing processes and the resulting products. However, a high-level coordination of the metrology community is currently absent in this field and consequently this limits the impact of metrology developments on advanced manufacturing. In this article we introduce the new European Metrology Network (EMN) for Advanced Manufacturing within EURAMET, the European Association of National Metrology Institutes (NMIs). The EMN is intended to be operated sustainably by NMIs and Designated Institutes in close cooperation with Stakeholders interested in advanced manufacturing. The objectives of the EMN are to set up a permanent stakeholder dialogue, to develop a Strategic Research Agenda for the metrology input required for advanced manufacturing technologies, to create and maintain a knowledge sharing programme and to implement a web-based service desk for stakeholders. The EMN development is supported by a Joint Network Project within the European Metrology Programme for Innovation and Research. KW - Stakeholder KW - Advanced manufacturing KW - Metrology KW - European Metrology Networks (EMNs) KW - Strategic Research Agenda (SRA), PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530618 DO - https://doi.org/10.1088/1361-6501/ac0d25 VL - 32 IS - 11 SP - 111001 PB - IOP Publishing AN - OPUS4-53061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute T1 - Tumore abbilden, Biomarker nachweisen, Messungen standardisieren N2 - Zu den am häufigsten eingesetzten Analysemethoden in den Lebens- und Materialwissenschaften gehören Lumineszenzmethoden. Sie nutzen die Emission von Licht nach Absorption von Energie, um Signale zu erzeugen, und umfassen spektroskopische und mikroskopische Messungen. KW - Quality assurance KW - Sensor KW - Imaging KW - Reference material KW - Nano KW - Particle KW - Nanomaterial KW - Upconversion KW - Nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Excitation KW - Power density KW - Single particle KW - Brightness KW - NIR PY - 2021 SP - 75 EP - 77 PB - GDCH AN - OPUS4-53526 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fiedler, Saskia A1 - Tserkezis, C. A1 - Wolff, C. A1 - Mortensen, N. A. A1 - Raza, S. A1 - Stamatopoulou, E. P. A1 - Sugimoto, H. A1 - Fuji, M. T1 - Cathodoluminescence of Silicon Nanoparticles N2 - In this work, Mie resonances in single Si nanoparticles (NPs) of different sizes have been systematically studied, using dark field (DF) and cathodoluminescence (CL) spectroscopy. An analytical method has been developed to compare experiment with theory. Experimental CL spectra are averaged over entire Si NPs, allowing for direct comparison to DF spectra of identical NPs. Theoretical spectra clarify the assignment of Mie resonances within the NP which contribute with different intensity in DF and CL, resulting in an apparent spectral shift. Furthermore, a substrate effect appears. A 100 nm-Si NP on 15 nm SiN results in a broad peak, spectrally in between that of the calculated electric and magnetic dipole, a NP on 50 nm SiN exhibits two separated peaks as theoretically predicted. High spatial resolution of electron beam excitation allows to study the spectral CL changes at varying beam impact parameters. Theory and experiment agree that depending on beam position within a small Si NP, relative intensity of electric and magnetic dipole change; electric dipole vanishing in the center of the NP. Similar results are found for larger (d = 210 nm) Si NPs although the mode assignment is challenging as higher order modes appear and overlap with others. In conclusion, comparison of CL and DF spectra is not trivial, in fact, excitation/radiation of distinct Mie resonances within a single Si NP are dependent on beam placement. However, substrate effects need to be considered in CL. T2 - European Material Research Society Fall Meeting 2021 CY - Online meeting DA - 20.09.21 KW - Cathodoluminescence KW - Silicon nanoparticles KW - Mie resonances PY - 2021 AN - OPUS4-53439 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reichelt, Manuel A1 - Cappella, Brunero T1 - Micro- and nanowear of self-mated steel generated and studied with an AFM at the single asperity level N2 - We show for the first time tribotests performed with self-mated 100Cr6 steel, taking advantage of an AFM, employed as a tribometer for the tribotests as well as for the inspection of wear of both tribopartners. Emphasis is put on the morphology of the scars, on wear particles, and on wear of the “colloidal” particles glued on the AFM cantilever. Measurements demonstrate the possibility of characterizing single asperity events leading to very small wear. We highlight several phenomena, which are elementary key constituents of tribological processes. Such phenomena, probably occurring also at the macroscale, can be detected, identified, and characterized with high spatial and time resolution only at the nanoscale, thus giving insight into conditions and causes of their emergence. KW - Nanowear KW - Atomic force microscope KW - 100Cr6 (AISI 52100) steel KW - Wear particles KW - Single asperity contact KW - Particle transfer KW - Zero wear PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531389 DO - https://doi.org/10.3389/fmech.2021.722434 SN - 2297-3079 VL - 7 SP - 1 EP - 16 PB - Frontiers Media CY - Lausanne AN - OPUS4-53138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - VAMAS TWA 37 - Quantitative Microstructural Analysis & Liaison with ISO/TC 202 Microbeam Analysis, Liaison with ISO 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. 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. T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 46th Steering Committee Meeting CY - Online meeting DA - 08.09.2021 KW - VAMAS KW - Nanoparticles KW - Standardisation KW - Inter-laboratory comparison KW - ISO/TC 202 KW - ISO/TC 229 KW - ISO/TC 201 KW - Microstructure KW - EBSD PY - 2021 UR - http://www.vamas.org/twa/ AN - OPUS4-53237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fiedler, Saskia A1 - Mortensen, N. A. A1 - Wolff, C. A1 - Morozov, S. A1 - Illiushyn, L. A1 - Booth, T. J. A1 - Stenger, N. A1 - Tserkezis, C. T1 - Giant photon bunching of WS2 monolayer in cathodoluminescence N2 - Cathodoluminescence (CL) spectroscopy has become a powerful tool to study nanostructures due to its high spectral and spatial resolution down to sub-nanometer. More recently, CL technique has also been used for second order auto-correlation measurements (g(2)(t)) to identify different single photon emitters and photon bunching in different materials [1-2]. In this work, tungsten disulfide (WS2) monolayers encapsulated in hexagonal boron nitride (hBN) with and without monocrystalline Au nanodisks (NDs) have been studied, using CL and PL spectroscopy as well as g(2)-CL- and PL-measurements. CL and PL maps of different WS2 monolayers before/after Au ND deposition show a narrow peak at ~625 nm without any background emission. In CL, the hBN not only protects WS2 from the electron beam but also acts as a charge carrier sink which substantially increases the CL signal [3]. A further CL enhancement is achieved by Au ND deposition, exhibiting the maximum at the center of the NDs without any size dependence. The PL intensity is unaffected. This indicates that Purcell enhancement cannot be the underlying mechanism. Furthermore, a giant CL-photon bunching of the hBN-encapsulated WS2 monolayers is found which is independent of the applied voltage but highly dependent on the electron beam current. At the lowest current of ~2 pA, a CL bunching factor of up to 160 is observed. Varying thicknesses of the surrounding hBN increases the overall CL signal but does not affect the bunching factor, though it exhibits small local changes within the same flake. In contrast, there is no PL correlation (g(2)(0) = 1). Interestingly, this photon bunching can be further increased by Au NDs, resulting in the highest ever observed bunching factor of close to 2200. Once again, this enhancement is independent of the Au ND’s diameter although some disks show higher bunching factors than others. Most likely, the Au acts as shield for the incoming primary electrons, resulting in an even further decreased current, and thereby, increased bunching. In conclusion, large CL-photon bunching is found in hBN-encapsulated WS2 monolayers which can be substantially enhanced by Au NDs. References [1] M.A. Feldmann, E.F. Demitrescu, D. Bridges, M.F. Chisholm, R.B. Davidson, P.G. Evans, J.A. Hachtel, A. Hu, R.C. Pooser, R.F. Haglund, B.J. Lawrie, Phys. Rev. B, 97, 081404(R) (2018) [2] S. Meuret, L.H.G. Tizei, T. Cazimajou, R. Bourrellier, H.C. Chang, F. Treussartm M. Kociak, Phys. Rev. Letter, 114, 197401 (2015) [3] S. Zheng, J.-K. So, F. Liu, Z. Liu, N. Zheludev, H.J. Fan, Nano Lett., 17, 6475-6480 (2017) T2 - GSELOP2021 CY - Paris, France DA - 23.08.2021 KW - Cathodoluminescence KW - Photon bunching KW - 2D materials KW - TMDCs KW - Au nanodisks KW - Transition metal dichalcogenide KW - Au nanoparticles PY - 2021 AN - OPUS4-53153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Feltin, N. A1 - Crouzier, L. A1 - Cios, G. A1 - Tokarski, T. T1 - Correlative imaging analysis of non-spherical nanoparticles N2 - It sounds like being a simple analytical task, it is definitely not. The way toward accurate measurement of the size distribution of nanoparticles (NPs) with complex shape, having a broad size polydispersity, with inhomogeneous chemistry, and with a high degree of agglomeration/aggregation is very challenging for all available analytical methods. Particularly for the NPs with complex shape, the access to the smallest dimension (as e.g. required for regulatory purposes) can be enabled only by using imaging techniques with spatial resolution at the nanoscale. Moreover, the full 3D-chacterisation of the NP shape can be provided either by advanced characterization techniques like 3D-TEM tomography or by correlative analysis, i. e. synergetic/complementary measurement of the same field-of-view of the sample with different probes. Examples of the latter type of analysis are: i) electron microscopy for the lateral dimensions and AFM for the height of the NPs, ii) SEM with STEM-in-SEM (also called T-SEM), iii) Electron Microscopy with TKD (Transmission Kikuchi Diffraction) for determination of the geometrical orientation of crystalline NPs, iv) Raman and SEM for e.g. thickness of graphen flakes, or v) Electron Microscopy for descriptive NP shape and SAXS for the NP concentration, the latter as a NP property able to be measured with higher and higher accuracy. For all these types of measurement, reference NPs are necessary for the validation of the measured size. Particularly non-spherical reference NPs are still missing. Examples of such new reference NPs as characterized by the correlative analyses enumerated above will be presented in detail in the contribution. T2 - 2021 Fall Meeting of the European Materials Research Society (E-MRS) CY - Online meeting DA - 20.9.2021 KW - Nanoparticles KW - Transmission Kikuchi Diffraction (TKD) KW - Correlative imaging KW - Electron microscopy KW - AFM KW - TiO2 KW - VAMAS PY - 2021 UR - https://www.european-mrs.com/meetings/2021-fall-meeting AN - OPUS4-53367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolmangadi, Mohamed Aejaz A1 - Schönhals, Andreas T1 - Phase Behaviour and Molecular Mobility of a confined Ionic Liquid Crystal N2 - Liquid crystalline mesophases in nanoconfinement exhibit intriguing orientational order and phase transition behaviors. Here, the plastic crystal to hexagonal columnar, and hexagonal columnar to isotropic transition temperatures are studied for the guanidinium-based ionic discotic liquid crystal confined in self- ordered nanoporous alumina membranes. The phase transition temperature of the plastic crystal to hexagonal columnar phase is reduced with inverse pore diameter. The hexagonal columnar to isotropic transition is suppressed completely in all pores and a possible explanation is given. The results are of technological relevance for the design of liquid crystal-based devices such as batteries and sensors with optimum tunable properties. T2 - Interpore Konferenz CY - Online meeting DA - 31.05.2021 KW - Ionic Liquid crystals KW - Nanoconfinement KW - Conductivity PY - 2021 AN - OPUS4-53298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul A1 - Kuchenbecker, Petra A1 - Hodoroaba, Vasile-Dan A1 - Rabe, Torsten T1 - Comparative study of suitable preparation methods to evaluate irregular shaped, polydisperse nanoparticles by scanning electron microscopy (SEM). N2 - Reliable characterization of materials at the nanoscale regarding their physio-chemical properties is a challenging task, which is important when utilizing and designing nanoscale materials. Nanoscale materials pose a potential toxicological hazard to the environment and the human body. For this reason, the European Commission amended the REACH Regulation in 2018 to govern the classification of nanomaterials, relying on number-based distribution of the particle size. Suitable methods exist for the granulometric characterization of monodisperse and ideally shaped nanoparticles. However, the evaluation of commercially available nanoscale powders is problematic. These powders tend to agglomerate, show a wide particle size distribution and are of irregular particle shape. Zinc oxide, aluminum oxide and cerium oxide with particle sizes less than 100 nm were selected for the studies and different preparation methods were used comparatively. First, the nanoparticles were dispersed in different dispersants and prepared on TEM-supported copper grids. Furthermore, individual powders were deposited on carbon-based self-adhesive pads. In addition, the samples were embedded by hot mounting and then ground and polished. The prepared samples were investigated by scanning electron microscopy (including the transmission mode STEM-in-SEM) and Dynamic Light scattering. The software package ImageJ was used to segment the SEM images and obtain the particle sizes and shapes and finally the number-based particles size distribution with size expressed as various descriptors. T2 - Ceramics 2021 CY - Online meeting DA - 19.04.2021 KW - Nanoparticles KW - Preparation KW - Characterization PY - 2021 AN - OPUS4-53272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob T1 - The Meticulous Approach: Fully traceable X-ray scattering data via a comprehensive lab methodology N2 - To find out if experimental findings are real, you need to be able to repeat them. For a long time, however, papers and datasets could not necessarily include sufficient details to accurately repeat experiments, leading to a reproducibility crisis. It is here, that the MOUSE project (Methodology Optimization for Ultrafine Structure Exploration) tries to implement change – at least for small- and wide-angle X-ray scattering (SAXS/WAXS). In the MOUSE project, we have combined: a) a comprehensive laboratory workflow with b) a heavily modified, highly automated Xenocs Xeuss 2.0 instrumental component. This combination allows us to collect fully traceable scattering data, with a well-documented data flow (akin to what is found at the more automated beamlines). With two full-time researchers, the lab collects and interprets thousands of datasets, on hundreds of samples for dozens of projects per year, supporting many users along the entire process from sample selection and preparation, to the analysis of the resulting data. While these numbers do not light a candle to those achieved by our hardworking compatriots at the synchrotron beamlines, the laboratory approach does allow us to continually modify and fine-tune the integral methodology. So for the last three years, we have incorporated e.g. FAIR principles, traceability, automated processing, data curation strategies, as well as a host of good scattering practices into the MOUSE system. We have concomitantly expanded our purview as specialists to include an increased responsibility for the entire scattering aspect of the resultant publications, to ensure full exploitation of the data quality, whilst avoiding common pitfalls. This talk will discuss the MOUSE project1 as implemented to date, and will introduce foreseeable upgrades and changes. These upgrades include better pre-experiment sample scattering predictions to filter projects on the basis of their suitability, exploitation of the measurement database for detecting long-term changes and automated flagging of datasets, and enhancing MC fitting with sample scattering simulations for better matching of odd-shaped scatterers. T2 - S4SAS CY - Online meeting DA - 01.09.2021 KW - X-ray scattering KW - Methodology KW - MOUSE KW - Data organization KW - Automation KW - Traceability PY - 2021 AN - OPUS4-53273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Sebastian A1 - Cappella, Brunero T1 - Friction and mechanical properties of AFM-scan-induced ripples in polymer films N2 - In the present paper, friction and mechanical properties of AFM-Scan-Induced ripple structures on films of polystyrene and poly-n-(butyl methacrylate) are investigated. Force volume measurements allow a quantitative analysis of the elastic moduli with nanometer resolution, showing a contrast in mechanical response between bundles and troughs. Additionally, analysis of the lateral cantilever deflection shows a clear correlation between friction and the sample topography. Those results support the theory of crack propagation and the formation of voids as a mechanism responsible for the formation of ripples. This paper also shows the limits of the presented measuring methods for soft, compliant, and small structures. KW - AFM KW - Polymer KW - Ripples KW - Mechanical properties KW - Friction PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532772 DO - https://doi.org/10.3389/fmech.2021.672898 SN - 2297-3079 VL - 7 SP - 1 EP - 8 PB - Frontiers Media CY - Lausanne AN - OPUS4-53277 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hodoroaba, Vasile-Dan T1 - Delivering Impact - A new ISO standard on the identification of nanoparticles N2 - Nanoparticles (NPs) are tiny – around 1 to 100 billionths of a meter – and can have different chemistries and behaviours than the same material of larger size. This property has led to advances in a wide range of industries, but it can also confer toxicity. Size measurements are the main way NPs are identified but a lack of standardised methods for identifying ones with complex shapes has hindered evaluation of their potential harm. KW - Nanoparticles KW - Standardisation KW - Particle size distribution KW - nPSize KW - ISO 21363 PY - 2024 UR - https://www.euramet.org/casestudies/casestudiesdetails/news/default-c3b26209e8 SP - 1 EP - 2 PB - EURAMET CY - Braunschweig AN - OPUS4-59626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Glimpses of the future: Systematic investigations of 1200 mofs using a highly automated, full-stack materials research laboratory N2 - By automatically recording as much information as possible in automated laboratory setups, reproducibility and traceability of experiments are vastly improved. This presentation shows what such an approach means for the quality of experiments in an X-ray scattering laboratory and an automated synthesis set-up. T2 - Winter School on Metrology and Nanomaterials for Clean Energy CY - Claviere, Italy DA - 28.01.2024 KW - Digitalization KW - Automation KW - Digital laboratory KW - Scattering KW - Synthesis KW - Nanomaterials KW - Holistic science PY - 2024 AN - OPUS4-59621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lindemann, Franziska T1 - Bestimmung der spezifischen Oberfläche mittels Gasadsorption (BET-Verfahren) N2 - Im Rahmen des 2. BAM-Akademie Info-Tages "Nano or not Nano" wurde die OECD TG 124 "Volume Specific Surface Area of Manufactured Nanomaterials" vorgestellt. Der Vortrag beschreibt die Bestimmung der spezifischen Oberfläche von dispersen und/oder porösen Pulvern mittels Gasadsorption nach dem BET-Verfahren. Es wird auf die Anwendbarkeit der Methode eingegangen und es werden praktische Hinweise zur Probenvorbereitung und Messung von Nanomaterialien gegeben. T2 - BAM Akademie II: Info-Tage "Nano or not Nano" CY - Online meeting DA - 25.01.2024 KW - OECD TG 124 KW - Nanopulver KW - VSSA KW - Nano powder KW - BET KW - Spezifische Oberfläche PY - 2024 AN - OPUS4-59623 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grauel, Bettina A1 - Würth, Christian A1 - Homann, C. A1 - Krukewitt, Lisa A1 - Andresen, Elina A1 - Roik, Janina A1 - Recknagel, Sebastian A1 - Haase, M. A1 - Resch-Genger, Ute T1 - Volume and surface effects on two-photonic and three-photonic processes in dry co-doped upconversion nanocrystals N2 - Despite considerable advances in synthesizing high-quality core/shell upconversion (UC) nanocrystals (NC; UCNC) and UCNC photophysics, the application of near-infrared (NIR)-excitable lanthanide-doped UCNC in the life and material sciences is still hampered by the relatively low upconversion luminescence (UCL) of UCNC of small size or thin protecting shell. To obtain deeper insights into energy transfer and surface quenching processes involving Yb3+ and Er3+ ions, we examined energy loss processes in differently sized solid core NaYF4 nanocrystals doped with either Yb3+ (YbNC; 20% Yb3+) or Er3+ (ErNC; 2% Er3+) and co-doped with Yb3+ and Er3+ (YbErNC; 20% Yb3+ and 2% Er3+) without a surface protection shell and coated with a thin and a thick NaYF4 shell in comparison to single and co-doped bulk materials. Luminescence studies at 375 nm excitation demonstrate backenergy transfer (BET) from the 4G11/2 state of Er3+ to the 2F5/2 state of Yb3+, through which the red Er3+ 4F9/2 state is efficiently populated. Excitation power density (P)-dependent steady state and time-resolved photoluminescence measurements at different excitation and emission wavelengths enable to separate surface-related and volume-related effects for two-photonic and threephotonic processes involved in UCL and indicate a different influence of surface passivation on the green and red Er3+ emission. The intensity and lifetime of the latter respond particularly to an increase in volume of the active UCNC core. We provide a threedimensional random walk model to describe these effects that can be used in the future to predict the UCL behavior of UCNC. KW - Nano KW - Nanomaterial KW - Upconversion KW - Nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Pphotophysics KW - Lifetime KW - Sensor KW - Excitation KW - Power density KW - Single particle KW - Brightness KW - NIR KW - Mechanism KW - Modeling KW - Simulation KW - Energy transfer PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535317 DO - https://doi.org/10.1007/s12274-021-3727-y SN - 1998-0124 VL - 15 IS - 3 SP - 2362 EP - 2373 PB - Springer AN - OPUS4-53531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andresen, Elina A1 - Islam, Fahima A1 - Prinz, Carsten A1 - Gehrmann, P. A1 - Licha, K. A1 - Roik, Janina A1 - Recknagel, Sebastian A1 - Resch-Genger, Ute T1 - Assessing the reproducibility and up‑scaling of the synthesis of Er,Yb‑doped NaYF4‑based upconverting nanoparticles and control of size, morphology, and optical properties N2 - Lanthanide-based, spectrally shifting, and multi-color luminescent upconverting nanoparticles (UCNPs) have received much attention in the last decades because of their applicability as reporter for bioimaging, super-resolution microscopy, and sensing as well as barcoding and anti-counterfeiting tags. A prerequisite for the broad application of UCNPs in areas such as sensing and encoding are simple, robust, and easily upscalable synthesis protocols that yield large quantities of UCNPs with sizes of 20 nm or more with precisely controlled and tunable physicochemical properties from lowcost reagents with a high reproducibility. In this context, we studied the reproducibility, robustness, and upscalability of the synthesis of β-NaYF4:Yb, Er UCNPs via thermal decomposition. Reaction parameters included solvent, precursor chemical compositions, ratio, and concentration. The resulting UCNPs were then examined regarding their application-relevant physicochemical properties such as size, size distribution, morphology, crystal phase, chemical composition, and photoluminescence. Based on these screening studies, we propose a small volume and high-concentration synthesis approach that can provide UCNPs with different, yet controlled size, an excellent phase purity and tunable morphology in batch sizes of up to at least 5 g which are well suited for the fabrication of sensors, printable barcodes or authentication and recycling tags. KW - Photoluminescence KW - Nano KW - Nanomaterial KW - Synthesis KW - Reproducibility KW - Upconversion nanoparticle KW - Lanthanide PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570170 DO - https://doi.org/10.1038/s41598-023-28875-8 SN - 2045-2322 VL - 13 IS - 1 SP - 1 EP - 13 AN - OPUS4-57017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieg, H. A1 - Krause, B.-C. A1 - Kästner, Claudia A1 - Böhmert, L. A1 - Lichtenstein, D. A1 - Tentschert, J. A1 - Jungnickel, H. A1 - Laux, P. A1 - Braeuning, A. A1 - Fessard, V. A1 - Thünemann, Andreas A1 - Luch, A. A1 - Lampen, A. T1 - Cellular Effects of In Vitro-Digested Aluminum Nanomaterials on Human Intestinal Cells N2 - Aluminum (Al) can be taken up from food, packaging, or the environment and thus reaches the human gastrointestinal tract. Its toxic potential after oral uptake is still discussed. The fate of different solid and ionic Al species during the passage through the digestive tract is the focus of this research, as well as the cellular effects caused by these different Al species. The present study combines the physicochemical processing of three recently studied Al species (metallic Al0, mineral Al2O3, and soluble AlCl3) in artificial digestion fluids with in vitro cell systems for the human intestinal barrier. Inductively coupled plasma mass spectrometry (ICP-MS) and small-angle X-ray scattering (SAXS) methods were used to characterize the Al species in the artificial digestion fluids and in cell culture medium for proliferating and differentiated intestinal Caco-2 cells. Cytotoxicity testing and cellular impedance measurements were applied to address the effects of digested Al species on cell viability and cell proliferation. Microarray-based transcriptome analyses and quantitative real-time PCR were conducted to obtain a deeper insight into cellular mechanisms of action and generated indications for cellular oxidative stress and an influence on xenobiotic metabolism, connected with alterations in associated signaling pathways. These cellular responses, which were predominantly caused by formerly ionic Al species and only at very high concentrations, were not impacted by artificial digestion. A two-directional conversion of Al between ionic species and solid particles occurred throughout all segments of the gastrointestinal tract, as evidenced by the presence of nanoscaled particles. Nevertheless, this presence did not increase the toxicity of the respective Al species. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2020 DO - https://doi.org/10.1021/acsanm.9b02354 VL - 3 IS - 3 SP - 2246 EP - 2256 PB - American Chemical Society AN - OPUS4-50632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fareed, Adnan A1 - Rosalie, Julian M. A1 - Kar, Satyakam A1 - Fähler, Sebastian A1 - Maaß, Robert T1 - Small-scale functional fatigue of a Ni-Mn-Ga Heusler alloy N2 - Functional fatigue of shape-memory alloys is a considerable threat to the reliable service of actuation devices. Here, we demonstrate the essentially degradation-free cyclic phase-transformation behavior of Ni-Mn-Ga microcrystals up to one million stress-driven superelastic cycles. Cyclic dissipation amounts to about 1/5 of the bulk counterpart and remains unaffected during cycling, even after the introduction of dislocation structures via plastic straining. Plastic yielding and the transformation stress largely exceed the known bulk values. However, the transformation-stress is found to depend on plastic pre-straining, which suggests that the size-affected transformation stress is sensitive to the initial defect structure and that it can be tuned by a targeted introduction of dislocations. These findings demonstrate the high suitability of Ni-Mn-Ga as a robust shape-memory alloy in small-scale functional device engineering. KW - Superelasticity KW - Shape-memory alloys KW - Functional fatigue KW - Ni-Mn-Ga PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600695 DO - https://doi.org/10.1016/j.actamat.2024.119988 VL - 274 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-60069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tokarski, T. A1 - Nolze, Gert T1 - Exploring Unconventional Uses of Kikuchi Pattern Analysis N2 - The characterization of really unknown phases typically uses 70 to 150 reflectors for lattice metric calculation. The determination of the lattice parameters follows with 4% accuracy. Including a Z correction up to 1% can be reached. The precision of the lattice parameters ratios (a:b:c) is, however, better than 0.1%. T2 - Oxford Users Meeting 2024 CY - Krakow, Poland DA - 14.05.2024 KW - EBSD KW - Kikuchi KW - Lattice parameters KW - Ratio refinement PY - 2024 AN - OPUS4-60086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wojciak, K. A1 - Tokarski, T. A1 - Cios, G. A1 - Nolze, Gert T1 - Precision and accuracy during standard-less mapping of local lattice distortions using ebsd and calm technique N2 - Electron Back Scatter Diffraction (EBSD) is a very versatile analytical technique allowing for the characterization of material structure. Historically, diffraction images (Kikuchi patterns) registered during EBSD analysis were solved using Hough/Radon transformation. The last decade brought several novel techniques of experimental pattern analysis, focusing entirely on image analysis routines such as pattern matching, or various variants of High-Resolution EBSD. However, all the above-mentioned techniques require prior knowledge of the material structure to perform orientation analysis. The recently presented algorithm employed in Crystallographic Analysis of Lattice Metric (CALM) software, effectively removes this limitation enabling a standard-less analytical approach in EBSD systems. At its core, the CALM technique couples accurate detection of the Kikuchi bands position, with a rigid construction of reciprocal lattice resulting from translational crystal symmetry. A unique characteristic of the methodology also gives an opportunity for application in the analysis of continuous lattice changes, for example tetragonality mapping. During mapping, however, the geometry of the gnomonic projection (represented by the projection center) is continuously altered decreasing overall algorithm efficiency. The work presents an analysis of the projection center in terms of precision and accuracy. T2 - Oxford User Meeting 2024 CY - Krakow, Poland DA - 14.05.2024 KW - EBSD KW - Kikuchi KW - Lattice parameters KW - Ratio refinement PY - 2024 AN - OPUS4-60087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fiedler, Saskia A1 - Frenzel, Florian A1 - Würth, Christian A1 - Tavernaro, Isabella A1 - Grüne, M. A1 - Schweizer, S. A1 - Engel, A. A1 - Resch-Genger, Ute T1 - Interlaboratory Comparison on Absolute Photoluminescence Quantum Yield Measurements of Solid Light Converting Phosphors with Three Commercial Integrating Sphere Setups N2 - Scattering luminescent materials dispersed in liquid and solid matrices and luminescent powders are increasingly relevant for fundamental research and industry. Examples are luminescent nano- and microparticles and phosphors of different compositions in various matrices or incorporated into ceramics with applications in energy conversion, solid-state lighting, medical diagnostics, and security barcoding. The key parameter to characterize the performance of these materials is the photoluminescence/fluorescence quantum yield (Φf), i.e., the number of emitted photons per number of absorbed photons. To identify and quantify the sources of uncertainty of absolute measurements of Φf of scattering samples, the first interlaboratory comparison (ILC) of three laboratories from academia and industry was performed by following identical measurement protocols. Thereby, two types ofcommercial stand-alone integrating sphere setups with different illumination and detection geometries were utilized for measuring the Φf of transparent and scattering dye solutions and solid phosphors, namely, YAG:Ce optoceramics of varying surface roughness, used as converter materials for blue light emitting diodes. Special emphasis was dedicated to the influence of the measurement geometry, the optical properties of the blank utilized to determine the number of photons of the incident excitation light absorbed by the sample, and the sample-specific surface roughness. While the Φf values of the liquid samples matched between instruments, Φf measurements of the optoceramics with different blanks revealed substantial differences. The ILC results underline the importance of the measurement geometry, sample position, and blank for reliable Φf data of scattering the YAG:Ce optoceramics, with the blank’s optical properties accounting for uncertainties exceeding 20%. KW - Nano KW - Fluorescence KW - Reference material KW - Luminescence KW - Quantitative spectroscopy KW - Particle KW - Quantum yield KW - Quality assurance KW - Phosphor KW - Converter material KW - Lifetime KW - Interlaboratory comparison KW - Method KW - Uncertainty PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600945 DO - https://doi.org/10.1021/acs.analchem.4c00372 SN - 0003-2700 SP - 6730 EP - 6737 PB - ACS Publications AN - OPUS4-60094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hodoroaba, Vasile-Dan A1 - Fontanges, Richard T1 - A new deep-learning AI tool for analysing images of complex nanoparticles N2 - A thousand times thinner than a human hair, nanoparticles (NPs) are finding applications in a range of modern products. However, as some can affect human health or the environment, knowing the types present is essential. Electron microscopy is the ‘gold standard’ for NP analysis, allowing identification based on manual size analysis, but a new method was required to analyse these particles quickly, accurately and in a consistent way. KW - Nanoparticles KW - Imaging KW - AI tool KW - Particle size and shape distribution PY - 2024 UR - https://www.euramet.org/casestudies/casestudiesdetails/news/a-new-deep-learning-ai-tool-for-analysing-images-of-complex-nanoparticles SP - 1 EP - 2 PB - EURAMET CY - Braunschweig AN - OPUS4-60095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Ongoing VAMAS ILC s on Nanoparticles and Graphene Oxide N2 - This contributions shows the first results of the ongoing interlaboratory comparisons under VAMAS/TWA 34 Nanoparticle populations related on the determination of pasrticle size distribution and relative concentration of nanoparticles and an example of an ILC running under VAMAS/TWA 41 Graphene and Related 2D Materials on the determination of the lateral diemsnions of graphene oxide flakes by Scanning Electron Microscopy. The link to related standardisation projects at ISO/TC Nanotechnologies are explained. T2 - Webinar Building the Foundation: Interlaboratory Comparisons and Reference Products for Advanced Materials CY - Berlin, Germany DA - 16.05.2024 KW - Nanoparticles KW - VAMAS KW - Interlaboratory comparison KW - Standardisation KW - Electron microscopy KW - AFM KW - SAXS PY - 2024 AN - OPUS4-60097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - About Interlaboratory Comparisons (ILCs) and VAMAS N2 - Advanced materials, such as nanomaterials, 2D materials, or thin films, play a crucial role in driving economic development and addressing major challenges in the coming years. These challenges include mitigating the impact of climate change, advancing lightweight engineering, enhancing catalysis, and improving medical applications. To comprehend the performance of these materials and ensure their acceptance across various sectors as safe and sustainable for both humans and the environment, the availability of reference procedures, materials, and data is essential. One versatile tool for establishing such references and evaluating the proficiency of individual laboratories and their competencies is through (international) interlaboratory comparisons (ILC). Notably, initiatives like the Versailles Project on Advanced Materials and Standards (VAMAS) provide a platform for conducting ILCs. This webinar will showcase various examples of interlaboratory comparisons, illustrating their impact on the development of reference products. T2 - Webinar Building the Foundation: Interlaboratory Comparisons and Reference Products for Advanced Materials CY - Berlin, Germany DA - 16.05.2024 KW - Interlaboratory comparison KW - Reference products KW - VAMAS KW - Standardisation PY - 2024 AN - OPUS4-60096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yu, Z. A1 - Musnier, B. A1 - Wegner, Karl David A1 - Henry, M. A1 - Chovelon, B. A1 - Desroches-Castan, A. A1 - Fertin, A. A1 - Resch-Genger, Ute A1 - Bailly, S. A1 - Coll, J.-L. A1 - Usson, Y, A1 - Josserand, V. A1 - Le Gúevel, X. T1 - High-Resolution Shortwave Infrared Imaging of Vascular Disorders Using Gold Nanoclusters N2 - We synthesized a generation of water-soluble, atomically precise gold nanoclusters (Au NCs) with anisotropic Surface containing a short dithiol pegylated chain (AuMHA/TDT). The AuMHA/TDT exhibit a high brightness (QY ∼ 6%) in the shortwave infrared (SWIR) spectrum with a detection above 1250 nm. Furthermore, they show an extended half-life in blood (t1/2ß = 19.54 ± 0.05 h) and a very weak accumulation in organs. We also developed a non-invasive, whole-body vascular imaging system in the SWIR window with high-resolution, benefiting from a series of Monte Carlo image processing. The imaging process enabled to improve contrast by 1 order of magnitude and enhance the spatial Resolution by 59%. After systemic administration of these nanoprobes in mice, we can quantify vessel complexity in depth (>4 mm), allowing to detect very subtle vascular disorders non-invasively in bone morphogenetic protein 9 (Bmp9)-deficient mice. The combination of these anisotropic surface charged Au NCs plus an improved SWIR imaging device allows a precise mapping at high-resolution and an in depth understanding of the organization of the vascular network in live animals. KW - Nanoparticle KW - Nanosensor KW - Fluorescence KW - Metal cluster KW - NIR KW - SWIR KW - Photophysics KW - Ligand KW - Size KW - Surface chemistry KW - Quantum yield KW - Mechanism KW - Lifetime KW - Decay kinetics PY - 2020 DO - https://doi.org/10.1021/acsnano.0c01174 VL - 14 IS - 4 SP - 4973 EP - 4981 PB - ACS Publication AN - OPUS4-50671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Godard, A. A1 - Kalot, G. A1 - Pliquett, J. A1 - Busser, B. A1 - Le Guével, X. A1 - Wegner, Karl David A1 - Resch-Genger, Ute A1 - Russelin, Y. A1 - Coll, J.-L. A1 - Denat, F. A1 - Bodio, E. A1 - Goze, C. A1 - Sancey, L. T1 - Water-Soluble Aza-BODIPYs: Biocompatible Organic Dyes for High Contrast In Vivo NIR-II Imaging N2 - A simple NIR-II emitting water-soluble system has been developed and applied in vitro and in vivo. In vitro, the fluorophore quickly accumulated in 2D and 3D cell cultures and rapidly reached the tumor in rodents, showing high NIR-II contrast for up to 1 week. This very efficient probe possesses all the qualities necessary for translation to the clinic as well as for the development of NIR-II emitting materials. KW - Aza-BODIPY KW - NIR-II Imaging KW - In vivo imaging KW - organic dyes KW - SWIR KW - Cancer KW - Fluorescence PY - 2020 DO - https://doi.org/10.1021/acs.bioconjchem.0c00175 VL - 31 IS - 4 SP - 1088 EP - 1092 PB - ACS Publications AN - OPUS4-50695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübner, Oskar A1 - Resch-Genger, Ute A1 - Wegner, Karl David A1 - Hoffmann, Kristin T1 - Lifetime Barcoding of Polystyrene Beads with Fluorescent Nanocrystals for Fluorescent Lifetime Detection in Flow Cytometry N2 - Multiplexed encoding schemes of nano- and micrometer sized polymer particles with fluorescent dyes or quantum dots (QDs) and their optical detection, are of increasing interest for applications in the life sciences, for example in flow cytometry. Almost all strategies utilizing fluorescence focus on spectrally distinguishable emission bands or colors and different intensity levels as fluorescence codes. In this work the goal is to perform multiplexing with encoding fluorophores with different fluorescence lifetimes (LTs). In comparison to the spectral multiplexing strategies this has the advantage, that the different fluorescence LT codes can be measured with the same excitation and emission wavelength, thus reducing instrumental costs. Moreover, LTs should not depend on emitter concentration. Unlike organic dyes, the LTs of which are typically <10ns, the fluorescence LTs of ternary semiconductor QDs which represent a “green” alternative to conventional Cd-containing QDs are in the range of several hundred ns, independent of oxygen concentration, and can be tuned to a certain extent by chemical composition and surface chemistry. This presents a time region that can barely be covered by other emitters that have either much shorter or longer lifetimes. In this project, different encoding strategies will be assessed, and the encoded particles will then be used for fluorescence assays for the analysis of several targets in parallel. Therefore, the encoded particles will be functionalized with different target-specific bioligands and read out with a specifically designed flow cytometer enabling time-resolved fluorescence detection. With this instrument, the particles will be discriminated by their fluorescence LTs in one detection channel while the analytes will be quantified by fluorescence labels in a second channel in the intensity domain. T2 - Tag der Chemie 2019 CY - Berlin, Germany DA - 11.07.2019 KW - Multiplexing KW - Lifetime KW - Bead KW - Flow cytometry KW - Fluorescence KW - Quantum dot KW - InP KW - AIS KW - Dye KW - Encoding KW - Barcoding KW - Assay KW - Method PY - 2019 AN - OPUS4-49722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wegner, Karl David A1 - Coro, A. A1 - Marquez, R. M. A1 - Le Guevel, X. A1 - Juarez, B. H. A1 - Resch-Genger, Ute T1 - Exploring the photoluminescence of gold NCs and Ag2S NPs to boost their SWIR emission N2 - Current challenges and objectives for non-invasive optical bioimaging are deep tissue penetration, high detection sensitivity, high spatial and temporal resolution, and fast data acquisition. A promising spectral window to tackle these challenges is the short-wave infrared (SWIR) ranging from 900 nm to 1700 nm where scattering, absorption, and autofluorescence of biological components are strongly reduced compared to the visible/NIR. At present, the best performing SWIR contrast agents are based on nanomaterials containing toxic heavy-metal ions like cadmium or lead, which raises great concerns for biological applications. Promising heavy-metal free nanoscale candidates are gold nanoclusters (AuNCs) and Ag2S nanoparticles (NPs). The photoluminescence (PL) of both types of nanomaterials is very sensitive to their size, composition of their surface ligand shell, and element composition, which provides an elegant handle to fine-tune their absorption and emission features and boost thereby the size of the signals recorded in bioimaging studies. Aiming for the development of SWIR contrast agents with optimum performance, we dived deeper into the photophysical processes occurring in these nanomaterials, thereby exploring in depth how the environment, surface ligand composition, and the incorporation of transition metals influence the optical properties of AuNCs and Ag2S NPs. We observed a strong enhancement of the SWIR emission of AuNCs upon exposure to different local environments (in solution, polymer, and in the solid state). Addition of metal ions such as Zn2+ to Ag2S based NPs led to a strong PL enhancement, yielding PL quantum yields of about 10% and thus making them highly suitable for non-invasive deep imaging of vascular networks and 3D fluid flow mapping. T2 - NaNaX 10 - Nanoscience with Nanocrystals CY - Klosterneuburg, Austria DA - 03.07.2023 KW - Quantum dots KW - Ag2S KW - Fluorescence KW - SWIR KW - Gold nanocluster KW - Nanomaterial KW - bioimaging PY - 2023 AN - OPUS4-58104 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wegner, Karl David A1 - Coro, A. A1 - Le Guevel, X. A1 - Juarez, B. H. A1 - Resch-Genger, Ute T1 - SWIR luminescent nanomaterials – key chemical parameters for bright probes for in vivo bioimaging N2 - A current challenge for studying physio-pathological phenomena and diseaserelated processes in living organisms with non-invasive optical bioimaging is the development of bright optical reporters that enable deep tissue penetration, a high detection sensitivity, and a high spatial and temporal resolution. The focus of this project are nanomaterials, which absorb and emit in the shortwave infrared (SWIR) between ~900–2500 nm where scattering, absorption, and autofluorescence of the tissue are strongly reduced compared to the visible and NIR. T2 - QD2024 - 12th International Conference on Quantum Dots CY - Munich, Germany DA - 18.03.2024 KW - Quantum dots KW - Advanced nanomaterials KW - Fluorescence KW - Quality assurance KW - Gold nanocluster KW - Shortwave infrared KW - Spectroscopy KW - Bioimaging PY - 2024 AN - OPUS4-59783 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Pauli, J. A1 - Güttler, Arne A1 - Richter, Maria A1 - Fiedler, Saskia A1 - Frenzel, Florian A1 - Wegner, Karl David A1 - Würth, Christian T1 - Photoluminescence Quantum Yields of Luminescent Nanocrystals and Particles in the UV/vis/NIR/SWIR N2 - The rational design of functional luminescent materials such as semiconductor quantum dots and lanthanide-based upconversion nanoparticles, all photophysical and mechanistic studies, and the comparison of different emitters require accurate and quantitative photoluminescence measurements. Particularly the reliable determination of the key performance parameter photoluminescence quantum yield (f), the number of emitted per absorbed photons, and the brightness are of special importance for luminescence applications in the life and material sciences and nano(bio)photonics.[1] In this context, examples for absolute measurements of the photoluminescence quantum yields of UV/vis/NIR/SWIR emissive semiconductor quantum dots and rods, made from different materials, and spectrally shifting lanthanide upconversion nanocrystals with different surface chemistries in transparent matrices are presented including excitation wavelength and power density dependent studies utilizing integration sphere spectroscopy.[2,3] In addition, procedures for the absolute determination of the photoluminescence quantum yields of scattering dispersions of larger size quantum rods and differently sized inorganic particles have been developed as well as procedures for the characterization of solid luminescent nanomaterials such as different perovskites and YAG:Cer converter materials.[4] Thereby, challenges and pitfalls of f measurements in different wavelength regions including the SWIR and material-specific effects related to certain emitter classes are addressed, achievable uncertainties are quantified, and relative and absolute measurements of photoluminescence quantum yield measurements are compared to underline limitations of the former approach. Finally, a set of novel UV/vis/NIR quantum yield standards is presented including their certification with a complete uncertainty budget.[5] T2 - NANAX 10 CY - Klosterneuburg, Austria DA - 03.07.2023 KW - Fluorescence KW - Optical spectroscopy KW - Reference data KW - Traceability KW - NIR KW - Scattering KW - Reference material KW - Certification KW - Quality assurance KW - Dye KW - Reference product KW - SWIR KW - Nano KW - Particle KW - Perovskite KW - Integrating sphere spectroscopy KW - Quantum yield PY - 2023 AN - OPUS4-58238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieg, Holger A1 - Schaar, Caroline A1 - Fouquet, Nicole A1 - Böhmert, Linda A1 - Thünemann, Andreas A1 - Braeuning, Albert T1 - Particulate iron oxide food colorants (E 172) during artificial digestion and their uptake and impact on intestinal cells N2 - Iron oxide of various structures is frequently used as food colorant (E 172). The spectrum of colors ranges from yellow over orange, red, and brown to black, depending on the chemical structure of the material. E 172 is mostly sold as solid powder. Recent studies have demonstrated the presence of nanoscaled particles in E 172 samples, often to a very high extent. This makes it necessary to investigate the fate of these particles after oral uptake. In this study, 7 differently structured commercially available E 172 food colorants (2 x Yellow FeO(OH), 2 x Red Fe2O3, 1 x Orange Fe2O3 + FeO(OH) and 2 x Black Fe3O4) were investigated for particle dissolution, ion release, cellular uptake, crossing of the intestinal barrier and toxicological impact on intestinal cells. Dissolution was analyzed in water, cell culture medium and artificial digestion fluids. Small-angle X-ray scattering (SAXS) was employed for determination of the specific surface area of the colorants in the digestion fluids. Cellular uptake, transport and toxicological effects were studied using human differentiated Caco-2 cells as an in vitro model of the intestinal barrier. For all materials, a strong interaction with the intestinal cells was observed, albeit there was only a limited dissolution, and no toxic in vitro effects on human cells were recorded. KW - Toxicology KW - Nanoparticles KW - Small-angle X-ray scattering KW - SAXS PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593935 DO - https://doi.org/10.1016/j.tiv.2024.105772 VL - 96 SP - 1 EP - 12 PB - Elsevier BV AN - OPUS4-59393 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Maxi B. A1 - Böhmert, Linda A1 - Thünemann, Andreas A1 - Loeschner, Katrin A1 - Givelet, Lucas A1 - Fahrenson, Christoph A1 - Braeuning, Albert A1 - Sieg, Holger T1 - Influence of artificial digestion on characteristics and intestinal cellular effects of micro-, submicro- and nanoplastics N2 - The production of plastics is rising since they have been invented. Micro, submicro- and nanoplastics are produced intentionally or generated by environmental processes, and constitute ubiquitous contaminants which are ingested orally by consumers. Reported health concerns include intestinal translocation, inflammatory response, oxidative stress and cytotoxicity. Every digestive milieu in the gastrointestinal tract does have an influence on the properties of particles and can cause changes in their effect on biological systems. In this study, we subjected plastic particles of different materials (polylactic acid, polymethylmethacrylate, melamine formaldehyde) and sizes (micro- to nano-range) to a complex artificial digestion model consisting of three intestinal fluid simulants (saliva, gastric and intestinal juice). We monitored the impact of the digestion process on the particles by performing Dynamic Light Scattering, Scanning Electron Microscopy and Asymmetric Flow Field-Flow Fractionation. An in vitro model of the intestinal epithelial barrier was used to monitor cellular effects and translocation behavior of (un)digested particles. In conclusion, artificial digestion decreased cellular interaction and slightly increased transport of all particles across the intestinal barrier. The interaction with organic matter resulted in clear differences in the agglomeration behavior. Moreover, we provide evidence for polymer-, size- and surface-dependent cellular effects of the test particles. KW - Toxicology KW - General Medicine KW - Food Science KW - Nanoplastics KW - Nanoparticle KW - Dynamic Light Scattering KW - DLS PY - 2024 DO - https://doi.org/10.1016/j.fct.2023.114423 VL - 184 SP - 1 EP - 16 PB - Elsevier AN - OPUS4-59298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Alam, F. A1 - Wegner, Karl David A1 - Pouget, S. A1 - Amidani, L. A1 - Kvashnina, K. A1 - Aldakov, D. A1 - Reiss, P. T1 - Eu2+: A suitable substituent for Pb2+ in CsPbX3 perovskite nanocrystals? N2 - Eu2+ is used to replace toxic Pb2+ in metal halide perovskite nanocrystals (NCs). The synthesis implies injection of cesium oleate into a solution of europium (II) bromide at an experimentally determined optimum temperature of 130 ○C and a reaction time of 60 s. Structural analysis indicates the formation of spherical CsEuBr3 nanoparticles with a mean size of 43 ± 7 nm. Using EuI2 instead of EuBr2 leads to the formation of 18-nm CsI nanoparticles, while EuCl2 does not show any reaction with cesium oleate forming 80-nm EuCl2 nanoparticles. The obtained CsEuBr3 NCs exhibit bright blue emission at 413 nm (FWHM 30 nm) with a room temperature photoluminescence quantum yield of 39%. The emission originates from the Laporte-allowed 4f7–4f65d1 transition of Eu2+ and shows a PL decay time of 263 ns. The long-term stability of the optical properties is observed, making inorganic lead-free CsEuBr3 NCs promising deep blue emitters for optoelectronics. KW - Perovskite KW - Lead-free KW - fluorescence KW - anion-exchange PY - 2019 DO - https://doi.org/10.1063/1.5126473 SN - 0021-9606 VL - 151 SP - 231101-1 EP - 231101-7 PB - AIP Publishing AN - OPUS4-50696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Santos, C.I.L. A1 - Machado, W.S. A1 - Wegner, Karl David A1 - Gontijo, L.A.P. A1 - Bettini, J. A1 - Schiavon, M.A. A1 - Reiss, P. A1 - Aldakov, D. T1 - Hydrothermal Synthesis of Aqueous-Soluble Copper Indium Sulfide Nanocrystals and Their Use in Quantum Dot Sensitized Solar Cells N2 - facile hydrothermal method to synthesize water-soluble copper indium sulfide (CIS) nanocrystals (NCs) at 150 degrees C is presented. The obtained samples exhibited three distinct photoluminescence peaks in the red, green and blue spectral regions, corresponding to three size fractions, which could be separated by means of size-selective precipitation. While the red and green emitting fractions consist of 4.5 and 2.5 nm CIS NCs, the blue fraction was identified as in situ formed carbon nanodots showing excitation wavelength dependent emission. When used as light absorbers in quantum dot sensitized solar cells, the individual green and red fractions yielded power conversion efficiencies of 2.9% and 2.6%, respectively. With the unfractionated samples, the efficiency values approaching 5% were obtained. This improvement was mainly due to a significantly enhanced photocurrent arising from complementary panchromatic absorption. KW - Aqueous quantum dot KW - Solar cells KW - CUINS2 nanocrystals KW - Colloidal semiconductor nanocrystals PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517983 DO - https://doi.org/10.3390/nano10071252 VL - 10 IS - 7 SP - 1252 PB - MDPI AN - OPUS4-51798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Maxi B. A1 - Böhmert, Linda A1 - Thünemann, Andreas A1 - Loeschner, Katrin A1 - Givelet, Lucas A1 - Fahrenson, Christoph A1 - Braeuning, Albert A1 - Sieg, Holger T1 - Influence of artificial digestion on characteristics and intestinal cellular effects of micro-, submicro- and nanoplastics N2 - The production of plastics is rising since they have been invented. Micro, submicro- and nanoplastics are produced intentionally or generated by environmental processes, and constitute ubiquitous contaminants which are ingested orally by consumers. Reported health concerns include intestinal translocation, inflammatory response, oxidative stress and cytotoxicity. Every digestive milieu in the gastrointestinal tract does have an influence on the properties of particles and can cause changes in their effect on biological systems. In this study, we subjected plastic particles of different materials (polylactic acid, polymethylmethacrylate, melamine formaldehyde) and sizes (micro- to nano-range) to a complex artificial digestion model consisting of three intestinal fluid simulants (saliva, gastric and intestinal juice). We monitored the impact of the digestion process on the particles by performing Dynamic Light Scattering, Scanning Electron Microscopy and Asymmetric Flow Field-Flow Fractionation. An in vitro model of the intestinal epithelial barrier was used to monitor cellular effects and translocation behavior of (un)digested particles. In conclusion, artificial digestion decreased cellular interaction and slightly increased transport of all particles across the intestinal barrier. The interaction with organic matter resulted in clear differences in the agglomeration behavior. Moreover, we provide evidence for polymer-, size- and surface-dependent cellular effects of the test particles. KW - Toxicology KW - Nanoparticles KW - Dynamic Light Scattering KW - Nanoplastics KW - Microplastics KW - Reference Method KW - Reference Material PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593947 DO - https://doi.org/10.1016/j.fct.2023.114423 VL - 184 SP - 1 EP - 16 PB - Elsevier BV AN - OPUS4-59394 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wegner, Karl David A1 - Resch-Genger, Ute T1 - The 2023 Nobel Prize in Chemistry: Quantum dots N2 - The 2023 Nobel Prize in Chemistry was awarded to Aleksey I. Ekimov (prize share 1/3), Louis E. Brus (prize share 1/3), and Moungi G. Bawendi (prize share 1/3) for groundbreaking inventions in the field of nanotechnology, i.e., for the discovery and synthesis of semiconductor nanocrystals, also termed quantum dots, that exhibit size-dependent physicochemical properties enabled by quantum size effects. This feature article summarizes the main milestones of the discoveries and developments of quantum dots that paved the road to their versatile applications in solid-state lighting, display technology, energy conversion, medical diagnostics, bioimaging, and image-guided surgery. KW - Quantum dots KW - Semiconductor nanocrystals KW - Luminescence KW - Quantitative spectroscopy KW - Quantum yield KW - Advanced nanomaterials KW - Quality assurance KW - Energy transfer PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597843 DO - https://doi.org/10.1007/s00216-024-05225-9 VL - 2024 SP - 1 EP - 11 PB - Springer CY - Cham AN - OPUS4-59784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, L. A1 - Hsiao, I-L. A1 - Ebisch, Maximilian A1 - Vidmar, J. A1 - Dreiack, N. A1 - Böhmert, L. A1 - Stock, V. A1 - Braeuning, A. A1 - Loeschner, K. A1 - Laux, P. A1 - Thünemann, Andreas A1 - Lampen, A. A1 - Sieg, H. T1 - The presence of iron oxide nanoparticles in the food pigment E172 N2 - Iron oxides used as food colorants are listed in the European Union with the number E172. However, there are no specifications concerning the fraction of nanoparticles in these pigments. Here, seven E172 products were thoroughly characterized. Samples of all colors were analyzed with a Broad spectrum of methods to assess their physico-chemical properties. Small-Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), zeta-potential, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), X-ray diffraction (XRD), Brunauer-Emmett-Teller analysis (BET), Asymmetric Flow Field-Flow Fractionation (AF4) and in vitro cell viability measurements were used. Nanoparticles were detected in all E172 samples by TEM or SAXS measurements. Quantitative results from both methods were comparable. Five pigments were evaluated by TEM, of which four had a size median below 100 nm, while SAXS showed a size median below 100 nm for six evaluated pigments. Therefore, consumers May be exposed to iron oxide nanoparticles through the consumption of food pigments. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2020 DO - https://doi.org/10.1016/j.foodchem.2020.127000 VL - 327 SP - 127000 PB - Elsevier Ltd. AN - OPUS4-50810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chowdhary, S. A1 - Moschner, J. A1 - Mikolajczak, D. J. A1 - Becker, M. A1 - Thünemann, Andreas A1 - Kästner, Claudia A1 - Klemczak, D. A1 - Stegemann, A.-K. A1 - Böttcher, C. A1 - Metrangolo, P. A1 - Netz, R. R. A1 - Koksch, B. T1 - The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation N2 - The hexapeptide hIAPP22–27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild‐type hIAPP′s toxicity to β‐cell death. In amyloid research, the role of hydrophobic and aromatic‐aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic‐aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS) to study the impact of side‐chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self‐assembly process. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Nanostructure KW - Peptide KW - Amyloid PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518632 DO - https://doi.org/10.1002/cbic.202000373 VL - 21 IS - 24 SP - 3544 EP - 3554 PB - Wiley CY - Weinheim AN - OPUS4-51863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Andresen, Elina A1 - Würth, Christian A1 - Weigert, Florian A1 - Frenzel, Florian T1 - Functional Luminophores – From Photophysics to Standardized Luminescence Measurements N2 - Inorganic nanocrystals with linear and nonlinear luminescence in the ultraviolet, visible, near infrared and short-wave infrared like semiconductor quantum dots and spectrally shifting lanthanide-based nanophosphors have meanwhile found applications in the life and material sciences ranging from optical reporters for bioimaging and sensing over security barcodes to solid state lighting and photovoltaics. These nanomaterials commonly have increasingly sophisticated core/shell particle architectures with shells of different chemical composition and thickness to minimize radiationless deactivation at the particle surface that is usually the main energy loss mechanism [1]. For lanthanide-based spectral shifters, particularly for very small nanoparticles, also surface coatings are needed which protect near-surface lanthanide ions from luminescence quenching by high energy vibrators like O-H groups and prevent the disintegration of these nanoparticles under high dilution conditions. [2,3,4]. The identification of optimum particle structures requires quantitative spectroscopic studies focusing on the key performance parameter photoluminescence quantum yield [5,6], ideally flanked by single particle studies to assess spectroscopic inhomogeneities on a particle-to-particle level for typical preparation methods [7,8], Moreover, in the case of upconversion nanoparticles with a multi-photonic and hence, excitation power density (P)-dependent luminescence, quantitative luminescence studies over a broad P range are required to identify particle architectures that are best suited for applications in fluorescence assays up to fluorescence microscopy. Here, we present methods to quantify the photoluminescence of these different types of emitters in the vis/NIR/SWIR and as function of P and demonstrate the importance of such measurements for a profound mechanistic understanding of the nonradiative deactivation pathways in semiconductor and upconversion nanocrystals of different size and particle architecture in different environments. T2 - Eingeladener Vortrag Uni Erlangen CY - Erlangen, Germany DA - 18.01.2023 KW - Semiconductor quantum dot KW - Upconversion nanocrystal KW - Luminescence KW - Quantitative spectroscopy KW - Photophysics KW - Quality assurance KW - Nano KW - Particle KW - Quantum yield KW - Lifetime KW - Standard KW - Reference material KW - Surface analysis KW - Quantification PY - 2023 AN - OPUS4-57011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Würth, Christian T1 - Time resolved spectroscopy of upconverting lanthanide based upconversion nanocrystals N2 - The optical properties of these materials strongly depend on the excitation power density, i.e., the number of photons absorbed per time interval. The upconversion quantum efficiencies (ΦUC) of these materials, the excitation power dependent population i.e. the emission characteristics, and the deactivation dynamics are influenced by nanoparticle architecture, doping concentration, and the microenvironment. We will discuss how time resolved measurements can help to understand the fundamental photophysical mechanisms and discuss differences to other nanocrystals like quantum dots. T2 - 19th International Course on “Principles and Applications of Time-resolved Fluorescence Spectroscopy” CY - Berlin, Germany DA - 16.11.2022 KW - Nanoparticle KW - Lanthanide KW - Upconversion KW - Energy transfer PY - 2022 AN - OPUS4-57000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meng, M. A1 - Zhang, R. A1 - Zhenlong, F. A1 - Yang, J. A1 - Ansari, A. A1 - Ou, Jun A1 - Würth, Christian A1 - Resch-Genger, Ute T1 - Retracted article: Effect of Ca2+ doping on the upconversion luminescence properties of NaYF4:Yb3+/Tm3+ nanoparticles and study of its temperature measurement performance N2 - A solvothermal method was used to prepare a series of Yb3+/Tm3+/Ca2+ co-doped NaYF4 nanoparticles with different Ca2+ contents. Strong upconversion blue fluorescence could be observed under 980 nm laser excitation of the samples. The effect of different Ca2+ contents on the luminescence intensity was investigated, and it was found that the UV-vis upconversion luminescence increased and then decreased with an increasing Ca2+ concentration during the increase of the Ca2+ content from 0 mol% to 25 mol%, reaching the strongest fluorescence at 15 mol%, which was up to about 28 times stronger than that without Ca2+ doping. Furthermore, the mechanism was investigated, and it was found that the doping of Ca2+ disrupted the symmetry of the crystal field, resulting in a significant enhancement of the overall fluorescence. Applied to fluorescence intensity ratio thermometry, the absolute and relative sensitivities are as high as 0.0418 K−1 and 2.31% K−1, respectively, with a minimum temperature resolution of 0.0129 K. KW - Sensor KW - Temperature KW - Lanthanide KW - Luminescence KW - Nanoparticles KW - Upconversion KW - Advanced materials PY - 2022 DO - https://doi.org/10.1039/D2CE00562J SN - 1466-8033 VL - 24 IS - 27 SP - 4887 EP - 4898 PB - Royal Society of Chemistry CY - London AN - OPUS4-56952 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Fürstenwerth, Paul A1 - Resch-Genger, Ute T1 - pH-Responsive Dyad Molecules: MiGraGen Project N2 - Optical pH sensors utilizing colorimetric or fluorescent indicator dyes are highly promising in many biomedical and life science applications where electrochemical sensors fail. For instance, optical sensors are not prone to electrical interferences, they are noninvasive and enable remote measurements. Moreover, fluorescence detection is very fast, highly sensitive, and provides several readout parameters ideal for multiplexing with nanometer resolution using simple, inexpensive, and miniaturizable instrumentation. Here, we present the design of a dyad sensor molecule, consisting of an analyte-responsive and an analyte inert reference fluorophore. T2 - MiGraGen Project Meeting 16.06.2023 CY - Online Meeting DA - 16.06.2023 KW - Dyad molecules KW - pH sensing KW - Fluorescent indicator KW - Ratiometric sensors PY - 2023 AN - OPUS4-58070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Fürstenwerth, Paul A1 - Eitinger, Lina A1 - Resch-Genger, Ute T1 - pH- and O2-Responsive Nanoparticles – The MiGraGen Project N2 - In recent years, the demand for reliable, versatile, fluorescent pH and oxygen sensors has increased rapidly in many biomedical applications since these analytes are important indicators of cell function or certain diseases. Therefore, sensor particles are needed that are small enough to penetrate cells, non-toxic, and allow for close-up optical monitoring. When developing such sensor systems, one must consider the pH and oxygen range detectable by the sensor dye and the matrix material of the used carrier particles. Here, we present the development of pH- and oxygen-responsive polymeric beads functionalized with fluorescent dyad molecules that consist of an analyte-responsive fluorophore and an analyte-inert dye. T2 - MiGraGen Project Meeting 09.08.2023 CY - Online Meeting DA - 09.08.2023 KW - Nano- and microsensors KW - Functionalized silica and polymeric particles KW - pH sensing KW - Oxygen sensing KW - Fluorescence PY - 2023 AN - OPUS4-58071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Matiushkina, Anna A1 - Litvinov, I. A1 - Bazhenova, A. A1 - Belyaeva, T. A1 - Dubavik, A. A1 - Veniaminov, A. A1 - Maslov, V. A1 - Kornilova, E. A1 - Orlova, A. A1 - Tavernaro, Isabella A1 - Andresen, Elina A1 - Prinz, Carsten A1 - Resch-Genger, Ute T1 - Synthesis and physical properties studies of bifunctional nanocomposites N2 - At present, the field of research on nanostructures is actively developing, which is due to their unique physico-chemical properties compared to bulk materials. Many research activities are focused on obtaining nanocomposites, which combine various types of nanostructures with different properties and function. For example, the development of magneto-luminescent nanocomposites makes it possible to use their luminescence for optical imaging, and their magnetic properties for magnetic targeted delivery and as agents of hyperthermia and magnetic resonance imaging. My master studies as part of the project Goszadanie 2019-1080 at ITMO were focused on the investigation of nanocomposites, consisting of semiconductor quantum dots (QDs) as luminescent component and superparamagnetic iron oxide nanoparticles (SPIONs) as magnetic one, in solution and during their incubation with HeLa cells. The spectrally resolved analysis of the QD photoluminescence (PL) kinetics of the free QDs and the QDs incorporated in these nanocomposites undergoing energy transfer processes allowed for (1) understanding the reasons for the quenching of QD luminescence in cells, (2) evaluating the average distance between the QDs and, based on this, concluding the degree of QD aggregation in cells, and (3) drawing conclusions about the QD-quencher composites integrity in cells. Overall, the analysis of the PL kinetics confirmed that QDs and SPIONs remain bound in the obtained nanocomposites during incubation with cells. To ensure the successful advancement of nanomaterials in biomedicine and the transition from their laboratory preparation and studies to their use in different applications and in industry, it is crucial to develop reliable measurement methods and reference materials candidates for the characterization of functional nanomaterials and assessing the quality of the obtained nanostructures. My recently started project at BAM, which is part of the EU metrology project MeTrINo, will be devoted to this topic. There we will focus on the development of methodologies for the synthesis and characterization of iron oxide nanoparticles, already used in biomedicine, and multi-element lanthanide-based nanoparticles with attractive upconversion luminescence, as reference materials with high monodispersity and reproducibility. Also, these nanoparticles will be functionalized with organic dyes for optical imaging and, probably, the study of the energy transfer phenomena. T2 - Bad Honnef Summer School CY - Bad Honnef, Germany DA - 30.07.2023 KW - Quantum dots KW - Iron oxide nanoparticles KW - Upconversion nanoparticles PY - 2023 AN - OPUS4-58075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osipova, Viktoriia A1 - Tavernaro, Isabella A1 - Prinz, Carsten A1 - Langhammer, N. A1 - Heinze, K. A1 - Resch-Genger, Ute T1 - Incorporation of near-infrared light emitting chromium (III) complexes into the core and shell of silica nanoparticles and optimisation of their optical properties N2 - In recent years, chromium (III) complexes have received a lot of attention as novel near-infrared (NIR) emitters. This interest was triggered by the report on the first molecular ruby Cr(ddpd)2(BF4)3 with a high photoluminescence quantum yield of 13.7% of its near infrared (NIR) emission band and a long luminescence lifetime of 1.122 ms at room temperature. Meanwhile, the influence of triplet oxygen, temperature, and pressure on the optical properties of different molecular rubies have been assessed. These features make these molecular rubies promising candidates for multi-analyte optical sensing applications and the generation of singlet oxygen for photocatalysis and photodynamic therapy. However, in an oxygen-containing environment, the photoluminescence quantum yields and luminescence lifetimes of these chromium(III) complexes show only very small values. This hampers their application as NIR luminescence labels. This application, that cannot be tackled by conventional deoxygenating approaches, requires suitable strategies to protect the luminescence of the chromium(III) complexes from oxygen quenching. Typical approaches to reduce the oxygen sensitivity of long-lived luminophores include the encapsulation into an oxygen-shielding matrix or less commonly employed, by tuning the bulkiness of the ligands for oxygen-sensitive coordination compounds. An elegant approach to reduce the undesired luminescence quenching by triplet oxygen explored by us presents the incorporation of these chromium(III) complexes into amorphous, non-porous silica nanoparticles, that can be simply surface functionalized, e.g., with targeting ligands and/or other sensor molecules. This can enable the use of such chromium(III) complexes as reporters for bioanalytical assays and bioimaging without the need to introduce reactive groups into the ligands and can pave the road to lifetime tuning. In this work, as first proof-of-concept experiments, a set of chromium (III) complexes constituting of different ligands and counter anions, were embedded into the core of silica nanoparticles. As an alternative synthesis strategy, selected complexes were incorporated into a silica shell formed around the core of self-made silica nanoparticles. Subsequently, the optical properties of the resulting luminescent silica nanoparticles were spectroscopically assessed by steady state and time-resolved luminescence spectroscopy. First results of time-resolved luminescence measurements of the Cr(ddpd)2(PF6)3 complex incorporated into 25nm large silica nanoparticles dispersed in aerated water in comparison to the decay kinetics obtained for this complex in acetonitrile in air showed an increase in lifetime from 46 µs to 1147 µs. This confirming our design concept of nanoscale NIR emissive Cr(III) reporters. T2 - Bad Honnef summer school CY - Bad Honnef, Germany DA - 30.07.2023 KW - Chromium (III) complexes KW - Silica Nanoparticles KW - Luminescence lifetime measurments PY - 2023 AN - OPUS4-58076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Correlative Morphological-Chemical Imaging of Nanostructured Materials N2 - Newly developed methodical approaches with an emphasis on correlative imaging analysis of morphology and chemistry of nanomaterials will be presented. Correlative imaging by high-resolution SEM with STEM-in-SEM as well as with EDS, and further with AFM, or with the new technique TKD (Transmission Kikuchi Diffraction) will be explained on various examples of nanostructures, both as starting materials and as embedded/functionalized nanoparticles in products. The unique analytical benefits of the Auger electron probe as a veritable nano-tool for the local surface chemistry will be highlighted. Examples of hybrid analysis of the bulk of nanomaterials by X-ray Spectroscopy and the highest surface-sensitive methods XPS and ToF-SIMS as advanced surface characterization methods available in the Competence Centre nano@BAM will be showed. Particularly for the spatially resolved analysis of the chemistry of nanostructures, such in-depth and lateral gradients of chemistry within mesoporous thin layers, or the completeness of the shells of core-shell nanoparticles, the latter methods are inherent. Other dedicated developments like approaches for the quantitative determination of the porosity of thin mesoporous layers by electron probe microanalysis (EPMA) with SEM or the quantitative determination of the roughness of particle surface by high-resolution imaging with electron microscopy will be also presented. T2 - Conference on Applied Surface and Solid Material Analysis AOFKA 2023 CY - Zurich, Switzerland DA - 11.09.2023 KW - Correlative imaging KW - Electron microscopy KW - X-ray spectroscopy KW - Nanostructures PY - 2023 UR - https://aofka23.scg.ch/ AN - OPUS4-58338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terborg, R. A1 - Procop, Mathias T1 - Theoretical calculation and experimental determination of x-ray production efficiencies for copper, zirconium, and tungsten N2 - The X-ray intensities of the K-, L- and M-lines of copper, zirconium and tungsten have been measured with an energy-dispersive X-ray spectrometer of known efficiency as function of photon energy. X-ray production efficiencies were determined from the measured intensities for Kα- and L-series of Cu and Zr and for the L- and M-series of W. These data were compared to calculated X-ray production efficiencies based on the widely used matrix correction models of Pouchou and Pichoir (XPP) and Bastin (PROZA96). Our results indicate that a replacement of the stopping power in the PROZA96 algorithm by expressions of Joy and Jablonski has only a minor influence on the calculated X-ray production efficiencies. In contrast, the modifications of the ionization cross-section show a stronger effect. We replaced the ionization cross-sections for K lines of the PROZA96 algorithm with different models. The results for L- and M-Lines are different. For the L-lines of Cu the original XPP and PROZA96 models show the best agreement while using the Bote cross-sections result in an overestimation. For the Zr-L and W-L1, -L2, -L3 X-ray production efficiencies, the Bote cross-sections lead to a significant improvement compared to all other models. The original XPP model represents the best agreement for the M5 efficiencies but underestimates the M4 efficiencies. There is no superior model or modification because the parameter sets in the models need to be aligned to each other. However, using the ionization cross-sections of Bote, which are based on quantum mechanical calculations, show promising results in many cases. KW - X-ray production efficiency KW - EPMA KW - Copper KW - Zirconium KW - Tungsten PY - 2023 DO - https://doi.org/10.1093/micmic/ozad067.110 SN - 1435-8115 VL - 29 IS - Supplement 1 SP - 245 EP - 246 PB - Oxford University Press CY - Oxford AN - OPUS4-58339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauli, J. A1 - Güttler, Arne A1 - Schneider, T. A1 - Würth, Christian A1 - Resch-Genger, Ute T1 - Fluorescence Quantum Yield Standards for the UV/Visible/NIR: Development, Traceable Characterization, and Certification N2 - The rational design of next generation molecular and nanoscale reporters and the comparison of different emitter classes require the determination of the fluorometric key performance parameter fluorescence quantum yield (Φf), i.e., the number of emitted photons per number of absorbed photons. Main prerequisites for reliable Φf measurements, which are for transparent luminophore solutions commonly done relative to a reference, i.e., a fluorescence quantum yield standard of known Φf, are reliable and validated instrument calibration procedures to consider wavelength-, polarization-, and time-dependent instrument specific signal contributions, and sufficiently well characterized fluorescence quantum yield standards. As the standard’s Φf value directly contributes to the calculation of the sample’s Φf, its accuracy presents one of the main sources of uncertainty of relative Φf measurements. To close this gap, we developed a first set of 12 fluorescence quantum yield standards, which absorb and emit in the wavelength region of 330−1000 nm and absolutely determined their Φf values with two independently calibrated integrating sphere setups. Criteria for standard selection and the configuration of these novel fluorescence reference materials are given, and the certification procedure is presented including homogeneity and stability studies and the calculation of complete uncertainty budgets for the certified Φf values. The ultimate goal is to provide the community of fluorescence users with available reference materials as a basis for an improved comparability and reliability of quantum yield data since the measurement of this spectroscopic key property is an essential part of the characterization of any new emitter. KW - Optical spectroscopy KW - Traceability KW - Reference product KW - Dye KW - Fluorescence KW - Quantum yield KW - Reference material KW - Reference data KW - Certification KW - Quality assurance PY - 2023 DO - https://doi.org/10.1021/acs.analchem.2c05530 VL - 95 SP - 5671 EP - 5677 PB - American Chemical Society AN - OPUS4-58151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oskolkova, Tatiana O. A1 - Matiushkina, Anna A. A1 - Borodina, Lyubov' N. A1 - Smirnova, Ekaterina S. A1 - Dadadzhanova, Antonina I. A1 - Sewid, Fayza A. A1 - Veniaminov, Andrey V. A1 - Moiseeva, Ekaterina O. A1 - Orlova, Anna O. T1 - FRET‐Amplified Singlet Oxygen Generation by Nanocomposites Comprising Ternary AgInS2/ZnS Quantum Dots and Molecular Photosensitizers N2 - Antibacterial photodynamic therapy (a‐PDT) has emerged as a promising non‐invasive therapeutic modality that utilizes the combination of a photosensitive agent, molecular oxygen, and excitation light to generate reactive oxygen species (ROS), demonstrating remarkable activity against multidrug‐resistant bacterial infections. However, the effective use of conventional photosensitizers is significantly limited by a number of their shortcomings, namely, poor water solubility and low selectivity. Herein, we present a novel biocompatible water‐soluble nanocomposite based on hydrophobic tetraphenylporphyrin (TPP) molecules and hydrophilic ternary AgInS2/ZnS quantum dots incorporated into a chitosan matrix as an improved photosensitizer for a‐PDT. We demonstrated that TPP molecules could be successfully transferred into chitosan solution while remaining primarily in the form of monomers, which are capable of singlet oxygen generation. We performed a detailed analysis of the Förster resonance energy transfer (FRET) between quantum dots and TPP molecules within the nanocomposite and proposed the mechanism of the singlet oxygen efficiency enhancement via FRET. KW - Nano KW - Particle KW - Quantum dot KW - Fluorescence KW - Synthesis KW - Optical spectroscopy KW - Energy transfer KW - Quality assurance KW - Lifetime KW - Quantum yield PY - 2024 DO - https://doi.org/10.1002/cnma.202300469 SN - 2199-692X VL - 10 IS - 3 SP - 1 EP - 11 PB - Wiley AN - OPUS4-59728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Labrador-Paez, Lucia, L. A1 - Kankare, J. A1 - Hyppanen, I. A1 - Soukka, T. A1 - Andresen, Elina A1 - Resch-Genger, Ute A1 - Widengren, J A1 - Liu, H. T1 - Frequency-Domain Method for Characterization of Upconversion Luminescence Kinetics N2 - The frequency-domain (FD) method provides an alternative to the commonly used time-domain (TD) approach in characterizing the luminescence kinetics of luminophores, with its own strengths, e.g., the capability to decouple multiple lifetime components with higher reliability and accuracy. While extensively explored for characterizing luminophores with down-shifted emission, this method has not been investigated for studying nonlinear luminescent materials such as lanthanide-doped upconversion nanoparticles (UCNPs), featuring more complicated kinetics. In this work, employing a simplified rate-equation model representing a standard two-photon energy-transfer upconversion process, we thoroughly analyzed the response of the luminescence of UCNPs in the FD method. We found that the FD method can potentially obtain from a single experiment the effective decay rates of three critical energy states of the sensitizer/activator ions involved in the upconversion process. The validity of the FD method is demonstrated by experimental data, agreeing reasonably well with the results obtained by TD methods. KW - Quality assurance KW - Luminescence KW - Method KW - Quantitative spectroscopy KW - Nano KW - Particle KW - Lifetime KW - Method development PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597435 DO - https://doi.org/10.1021/acs.jpclett.3c00269 SP - 3436 EP - 3444 AN - OPUS4-59743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Herausforderungen bei der Granulometrie von (technischen) Nano-Pulvern N2 - Einführungsvortrag im Rahmen der Veranstaltung der BAM-Akademie zur Anwendung der OECD TG 124 "Volume Specific Surface Area of Manufactured Nanomaterials" zu Herausforderungen bei der Granulometrie von Nanopulvern. Es werden die Einflüsse von Partikelform, Breite der Partikelgrößenverteilung und Agglomeration/ Aggregation auf das Messergebnis sowie die Vergleichbarkeit der Ergebnisse verschiedener Messverfahren dargelegt. T2 - BAM Akademie II: Info-Tage "Nano or not Nano" CY - Online meeting DA - 25.01.2024 KW - Nanopulver KW - Granulometrie KW - Partikelgröße KW - VSSA KW - OECD TG 124 PY - 2024 AN - OPUS4-59558 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emamverdi, Farnaz A1 - Huang, J. A1 - Mosane Razavi, Negar A1 - Bojdys, M. J. A1 - Forster, A. B. A1 - Budd, P. M. A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - Molecular Mobility and Gas Transport Properties of Mixed Matrix Membranes Based on PIM‑1 and a Phosphinine Containing Covalent Organic Framework N2 - Polymers with intrinsic microporosity (PIMs) are gaining attention as gas separation membranes. Nevertheless, they face limitations due to pronounced physical aging. In this study a covalent organic framework containing λ5-phosphinine moieties, CPSF-EtO were incorporated as a nanofiller (concentration range 0-10 wt%) into a PIM-1 matrix forming dense films with a thickness of ca. 100 μm. The aim of the investigation was to investigate possible enhancements of gas transport properties and mitigating effects on physical aging. The incorporation of the nanofiller occurred on aggregate level with domains up to 100 nm as observed by T-SEM and confirmed by X-ray scattering. Moreover, the X-ray data show that the structure of the microporous network of the PIM-1 matrix is changed by the nanofiller. As the molecular mobility is fundamental for gas transport as well as for physical aging, the study includes dielectric investigations of pure PIM-1 and PIM-1/CPSF-EtO mixed matrix membranes to establish a correlation between the molecular mobility and the gas transport properties. Using the time-lag method the gas permeability and the permselectivity were determined for N2, O2, CH4 and CO2 for samples with variation in filler content. A significant increase in the permeability of CH4 and CO2 (50 % increase compared to pure PIM-1) was observed for a concentration of 5 wt% of the nanofiller. Furthermore, the most pronounced change in the permselectivity was found for the gas pair CO2/N2 at a filler concentration of 7 wt%. KW - Polymers of Intrinsic Microporosity KW - Nanocomposites PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595031 DO - https://doi.org/10.1021/acs.macromol.3c02419 SN - 0024-9297 VL - 57 IS - 4 SP - 1829 EP - 1845 PB - ACS Publications AN - OPUS4-59503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - O'Connor, Daniel A1 - Evans, Alexander A1 - Balsamo, Alessandro A1 - Favres, Georges A1 - Przyklenk, Anita A1 - Bosse, Harald A1 - Phillips, Dishi T1 - European Metrology Network (EMN) for Advanced Manufacturing Development of the Strategic Research Agenda (SRA) N2 - The European Commission has identified Advanced Manufacturing and Advanced Materials as two of six Key Enabling Technologies (KETs). It is considered that Metrology is a key enabler for the advancement of these KETs. Consequently, EURAMET, the association of metrology institutes in Europe, has strengthened the role of Metrology for these KETs by enabling the creation of a European Metrology Network (EMN) for Advanced Manufacturing. The EMN is comprised of National Metrology Institutes (NMIs) and Designated Institutes (DIs) from across Europe and was formally established in October 2021. The aim of the EMN is to provide a high-level coordination of European metrology activities for the Advanced Manufacturing community. The EMN itself is organized in three sections representing the major stages of the manufacturing chain: 1) Advanced Materials, 2) Smart Manufacturing Systems, and 3) Manufactured Components & Products. The EMN for Advanced Manufacturing is engaging with stakeholders in the field of Advanced Manufacturing (large companies & SMEs, industry organisations, existing networks, and academia), as well as the wider Metrology community, including Technical Committees, to provide input for the Strategic Research Agenda (SRA) on Metrology for Advanced Manufacturing. This contribution will give an overview about the first version of the SRA prepared by the EMN for Advanced Manufacturing. T2 - Euspen, 23rd International Conference & Exhibitio CY - Copenhagen, Danmark DA - 13.06.2023 KW - European Metrology Network (EMN) KW - Advanced Manufacturing KW - Metrology KW - Strategic Research Agenda (SRA) PY - 2023 AN - OPUS4-59176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Bartczack, Dorota A1 - Taché, Olivier A1 - Hodoroaba, Vasile-Dan T1 - Report on the homogeneity assessment of bimodal gold materials (nPSize1 and nPSize2) and particle number concentration by frequency method N2 - The main objective was to assess homogeneity of two bimodal gold materials, namely nPsize1 and nPSize2, containing approximately 1:1 and 10:1 particle number-based ratio of ~30nm and ~60nm particles. Particle number-based concentration within the two size fractions was determined with spICP-MS using the particle frequency method of calibration. KW - Nanoparticles KW - Homogeneity KW - Particle number concentration KW - Gold KW - nPSize PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595451 DO - https://doi.org/10.5281/zenodo.10654245 SP - 1 EP - 5 PB - Zenodo CY - Geneva AN - OPUS4-59545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Einführung: Volume Specific Surface Area (VSSA) N2 - Im Rahmen der 2. BAM-Akademie-Veranstaltung "Nano or not Nano" wurde die OECD TG 124 "Volume Specific Surface Area of Manufactured Nanomaterials" vorgestellt. Der Vortrag enthält ein Einführung zur VSSA mit Definitionen, Vorteilen und Einschränkungen. T2 - BAM Akademie II: Info-Tage "Nano or not Nano" CY - Online meeting DA - 25.01.2024 KW - Nano powder KW - VSSA KW - Specific surface KW - OECD TG PY - 2024 AN - OPUS4-59560 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Bestimmung der Skelettdichte mittels Gaspyknometrie N2 - Im Rahmen des 2. BAM-Akademie Info-Tages "Nano or not Nano" wurde die OECD TG 124 "Volume Specific Surface Area of Manufactured Nanomaterials" vorgestellt. Der Vortrag beschreibt detailliert das Messverfahren der He-Gaspyknometrie zur Bestimmung der Skelettdichte von Pulvern und geht auf Anwendbarkeit, Besonderheiten bei Nanopulvern und wichtige Einstellparameter für die Messung ein. T2 - BAM Akademie II: Info-Tage "Nano or not Nano" CY - Online meeting DA - 25.01.2024 KW - Pycnometry KW - Density KW - Nano powder PY - 2024 AN - OPUS4-59561 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, Kun A1 - Carrod, Andrew J. A1 - Del Giorgio, Elena A1 - Hughes, Joseph A1 - Rurack, Knut A1 - Bennet, Francesca A1 - Hodoroaba, Vasile-Dan A1 - Harrad, Stuart A1 - Pikramenou, Zoe T1 - Luminescence Lifetime-Based Sensing Platform Based on Cyclometalated Iridium(III) Complexes for the Detection of Perfluorooctanoic Acid in Aqueous Samples N2 - Luminescence lifetimes are an attractive analytical method for detection due to its high sensitivity and stability. Iridium probes exhibit luminescence with long excited-state lifetimes, which are sensitive to the local environment. Perfluorooctanoic acid (PFOA) is listed as a chemical of high concern regarding its toxicity and is classified as a “forever chemical”. In addition to strict limits on the presence of PFOA in drinking water, environmental contamination from industrial effluent or chemical spills requires rapid, simple, accurate, and cost-effective analysis in order to aid containment. Herein, we report the fabrication and function of a novel and facile luminescence sensor for PFOA based on iridium modified on gold surfaces. These surfaces were modified with lipophilic iridium complexes bearing alkyl chains, namely, IrC6 and IrC12, and Zonyl-FSA surfactant. Upon addition of PFOA, the modified surfaces IrC6-FSA@Au and IrC12-FSA @Au show the largest change in the red luminescence signal with changes in the luminescence lifetime that allow monitoring of PFOA concentrations in aqueous solutions. The platform was tested for the measurement of PFOA in aqueous samples spiked with known concentrations of PFOA and demonstrated the capacity to determine PFOA at concentrations >100 μg/L (240 nM). KW - Perfluorooctanoic Acid (PFOA) KW - Cyclometalated iridium (III) complexes KW - Luminescent lifetime KW - Optically active surfaces KW - ToF-SIMS PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594535 UR - https://pubs.acs.org/doi/10.1021/acs.analchem.3c04289 DO - https://doi.org/10.1021/acs.analchem.3c04289 VL - 96 IS - 4 SP - 1565 EP - 1575 PB - American Chemical Society (ACS) AN - OPUS4-59453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krenzer, Julius A1 - Mueller, Thomas A1 - El Abbassi, Abdelouahad A1 - Resch-Genger, Ute A1 - Petrov, Eugene T1 - Aroyl-S,N-ketene acetal based bichromophores exhibiting energy transfer and aggregation induced (dual) emission N2 - A series of aroyl-S,N-ketene acetal based bichromophores is readily synthesized by Buchwald-Hartwig amination and Ullmann reaction in moderate to good yields. The aminated aroyl-S,N-ketene acetals are emissive in the solid state and in the aggregate, but not in solution, thus, they are AIEgens (aggregation induced emission chromogens). Aggregation is induced by fractional alternation of the solvent mixture, here by increasing the water fraction of ethanol/water mixtures. For most derivatives, the emission upon induced aggregation stems solely from the aroyl-S,N-ketene acetal chromophore, regardless whether excitation occurs at the absorption maximum of the triarylamine or the aroyl-S,N-ketene acetal. Therefore, a pronounced energy transfer from the triarylamine donor to the aroyl-S,N-ketene acetal acceptor can be inferred. The color of the emission can be controlled by choosing the para-aroyl substituent. A partial energy transfer could also be observed for some bichromophores, leading to aggregation-induced dual emission (AIDE). In addition, four examples of aminated diaroyl-S,N-ketene acetals were added to the compound library. The electron-withdrawing properties of the additional aroyl group provide a bathochromic shift of the emission band of the aroyl-S,N-ketene acetal. These bichromophores also show AIDE and in one case even aggregation-induced white light emission as a result of additive color mixing. T2 - Beilstein Symposium on pi-Conjugated Molecules and Materials CY - Limburg, Germany DA - 07.11.2023 KW - aggregation-induced dual emission (AIDE) PY - 2023 AN - OPUS4-59006 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Driscoll, Laura L. A1 - Driscoll, Elizabeth H. A1 - Dong, Bo A1 - Sayed, Farheen N. A1 - Wilson, Jacob N. A1 - O’Keefe, Christopher A. A1 - Gardner, Dominic J. A1 - Grey, Clare P. A1 - Allan, Phoebe K. A1 - Michalchuk, Adam A. L. A1 - Slater, Peter R. T1 - Under pressure: offering fundamental insight into structural changes on ball milling battery materials N2 - Synthesis of Li ion battery materials via ball milling has been a huge area of growth, leading to new high-capacity electrode materials, such as a number of promising disordered rocksalt (DRS) phases. In prior work, it was generally assumed that the synthesis was facilitated simply by local heating effects during the milling process. In this work, we show that ball milling Li2MoO4 leads to a phase transformation to the high pressure spinel polymorph and we report electrochemical data for this phase. This observation of the formation of a high pressure polymorph shows that local heating effects alone cannot explain the phase transformation observed (phenakite to spinel) and so indicates the importance of other effects. In particular, we propose that when the milling balls collide with the material, the resulting shockwaves exert a localised pressure effect, in addition to local heating. To provide further support for this, we additionally report ball milling results for a number of case studies (Li2MnO3, Li2SnO3, Nb2O5) which reinforces the conclusion that local heating alone cannot explain the phase transformations observed. The work presented thus provides greater fundamental understanding of milling as a synthetic pathway and suggests potential strategies to prepare such samples without milling (e.g., doping to create internal chemical pressure). In addition, we suggest that further research is needed into the effect of the use of milling as a route to smaller particles, since we believe that such milling may also be affecting the surface structure of the particles through the influence of the shockwaves generated. KW - Pollution KW - Nuclear Energy and Engineering KW - Sustainability and the Environment KW - Environmental Chemistry KW - Renewable Energy PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-590086 DO - https://doi.org/10.1039/d3ee00249g VL - 16 IS - 11 SP - 5196 EP - 5209 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Design and Quantitative Characterization of Functional Molecular Chromophores and Nanomaterials with UV/vis/NIR/IR Emission – An Overview of Research Activities in Division Biophotonics N2 - In the focus of division Biophotonics are the design, preparation, analytical and spectroscopic characterization, and application of molecular and nanoscale functional materials, particularly materials with a photoluminescence in the visible, near infrared (NIR) and short-wave infrared (SWIR). This includes optical reporters for bioimaging and sensing, security and authentication barcodes, and materials for solid state lighting, energy conversion, and photovoltaics. For the identification of optimum particle structures quantitative spectroscopic studies are performed under application-relevant conditions, focusing on the key performance parameter photoluminescence quantum yield. In addition, simple, cost-efficient, and standardizable strategies for quantifying functional groups on the surface of nano- and microparticles are developed, here with a focus on optical assays and electrochemical titration methods, cross-validated by more advanced methods such as quantitative NMR. In addition, reference materials and reference products are developed for optical methods, particularly luminescence techniques, and for analytical methods utilized for the characterization of nanomaterials. T2 - Projekttreffen Nile-Chrome 2.0 CY - Mainz, Germany DA - 11.12.2023 KW - Fluorescence KW - Quantum yield KW - Optical spectroscopy KW - Reference material KW - Reference data KW - Quality assurance KW - Dye KW - Reference product KW - NIR KW - SWIR KW - Nano KW - Particle KW - Silica KW - Polymer KW - Surface group analysis KW - Sensor molecules PY - 2023 AN - OPUS4-59123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Nirmalananthan-Budau, Nithiya A1 - Di Giacomo, Bruno A1 - Srivastava, Priyanka A1 - Scholtz, Lena A1 - Resch-Genger, Ute T1 - A Multimodal Approach to Quantify Surface Functional Groups and Ligands on Amorphous Silica Nanoparticles N2 - Nowadays amorphous silica nanoparticles (SiO2-NP) are one of the most abundant engineered nanomaterials, that are highly stable and can be easily produced on a large scale at low cost. Surface functionalized SiO2-NP are of great interest in the life and material sciences, as they can be used e.g. as drug carriers, fluorescent sensors, and multimodal labels in bioanalytical assays and imaging applications. Their performance in such applications depends not only on particle size, size distribution, and morphology, but also on surface chemistry, i.e. the total number of surface functional groups (FG) and the number of FG accessible for subsequent functionalization with ligands or biomolecules, which in turn determines surface charge, colloidal stability, biocompatibility, and toxicity. Aiming at the development of simple, versatile, and multimodal tools for the quantification of many bioanalytically relevant FG and ligands, we investigated and compared various analytical methods commonly used for FG quantification. This includes electrochemical titration methods, dye-based optical assays, and other instrumental analytical techniques such as nuclear magnetic resonance and thermal analysis methods. The potential of our multimodal approach for FG quantification was demonstrated for commercial and custom-made silica particles of varying FG, showing not only an influence of the synthesis methods on the number of FG but also on the performance. In the future, our strategy can contribute to establish multi-method characterization strategies to provide a more detailed picture of the structure-properties relationship. T2 - Advanced Materials Safety 2023 CY - Saarbrücken, Germany DA - 08.11.2023 KW - Amorphous silica particles KW - Surface group analysis KW - Ligands KW - Reference material KW - Optical spectroscopy KW - Quantitative NMR KW - Optical assays KW - Titration KW - Engineered nanomaterials KW - Advanced Materials PY - 2023 AN - OPUS4-59124 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Srivastava, Priyanka A1 - Scholtz, Lena A1 - Nirmalananthan-Budau, Nithiya A1 - Resch-Genger, Ute T1 - Multicolored sensors based on silica and polymeric particles for ratiometric monitoring of pH, oxygen and saccharides N2 - In recent years, the use of functionalized micro- and nanomaterials has increased rapidly for a wide range of applications in the life and material sciences, due to their unique properties in combination with their high surface-to-volume ratio and stability. For instance, functionalized micro- and nanomaterials, that are labeled or stained with a multitude of sensor dyes can be used for monitoring, and quantification of neutral and ionic analytes. These materials have several advantages as compared to conventional molecular probes like enhanced brightness, ease of designing ratiometric systems by combining analyte-sensitive and inert reference dyes, and increased photostability. Moreover, stained nanoparticles can enable the use of hydrophobic dyes in aqueous environments. Versatile templates and carriers for the fabrication of nanosensors by staining and/or labeling with different fluorophores and sensor molecules are biocompatible silica and polymeric particles, because they can be synthesized in large scales at low costs with different surface chemistries. Here we present our work on multicolored sensors for the measurement of pH, oxygen and saccharides utilizing commercially available or in-house synthesized silica and polymeric particles. T2 - 4th European Biosensor Symposium 2023 CY - Aachen, Deutschland DA - 27.08.2023 KW - Nano- and microsensors KW - Silica and polystyrene nanoparticles KW - PH probe KW - Ratiometric sensors KW - Optical spectroscopy KW - Dye KW - Saccharide sensing KW - Multicolored PY - 2023 AN - OPUS4-59125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Nirmalananthan-Budau, Nithiya A1 - Scholtz, Lena A1 - Resch-Genger, Ute T1 - A Multimodal Approach to Quantify Surface Functional Groups on Nanomaterials for Safe and Sustainable by Design N2 - Engineered nanomaterials (NM) with their large surface-to-volume ratios and their for some materials observed size-dependent functional properties are of increasing relevance for current and future developments in various fields such as medical and pharmaceutical industry, computing and electronics or food and consumer products. The performance and safety of NM are determined by the sum of their intrinsic physicochemical properties. Especially, the particle surface chemistry, which is largely controlled by the chemical nature and density of functional groups (FG) and ligands, is an important key driver for NM performance, stability, and processibility as well as the interaction of NM with the environment. Thus, methods for FG quantification can foster the sustainable development of functional and safe(r) NM. Aiming at the development of simple, versatile, and multimodal tools for the quantification of many bioanalytically relevant FG and ligands, we investigated and compared various analytical methods commonly used for FG quantification. This includes electrochemical titration methods, dye-based optical assays, and other instrumental analytical techniques such as nuclear magnetic resonance and thermal analysis methods. The potential of our multimodal approach for FG quantification was demonstrated for commercial and custom-made polymeric and silica particles of varying FG, used as optical pH sensors. In the future, our strategy can contribute to establish multi-method characterization strategies to provide a more detailed picture of the structure-properties relationship. T2 - NanoSAFE & NanoSafety Cluster 2023 CY - Grenoble, France DA - 05.06.2023 KW - Engineered Nanomaterials KW - Safe-by-Design KW - Sustainable-by-Design KW - Surface Group Analysis KW - Silica and Polystyrene Particles KW - Surface Modification KW - Dye KW - Optical Spectroscopy KW - Quantitative NMR KW - Electrochemical Titration KW - Functionalized Nanomaterials KW - Nanosafety PY - 2023 AN - OPUS4-59126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Nirmalananthan-Budau, Nithiya A1 - Scholtz, Lena A1 - Resch-Genger, Ute T1 - Development of multimodal methods to quantify the total and accessible number of functional groups and ligands on nanomaterials N2 - Engineered and tailored nanomaterials (NM) are of great interest in the life and material sciences, as they can be used, e.g., as drug carriers, barcodes, fluorescent sensors, and multimodal labels in bioanalytical assays and imaging applications. Their performance and safety depend not only on their particle size, size distribution, and morphology, but also on their surface chemistry, i.e., the total number of surface functional groups (FG) and the number of FG accessible for subsequent functionalization with ligands or biomolecules, which in turn determines surface charge, colloidal stability, biocompatibility, and toxicity. It also underlines the importance of validated analytical methods that provide accurate information on these application-relevant physicochemical properties with a known uncertainty. In the case of FG quantification, this calls for robust, fast, inexpensive, and reliable methods which allow for the characterization of a broad variety of NM differing in size, chemical composition, and optical properties. Methods Aiming at the development of simple, versatile, and multimodal tools for the quantification of bioanalytically relevant FG such as amine, carboxy, thiol, and aldehyde functionalities, we investigated and compared various analytical methods commonly used for FG quantification. This includes electrochemical titration methods, dye-based optical assays, and other instrumental analytical techniques such as nuclear magnetic resonance (NMR), mass spectrometry (MS), and thermal analysis methods. Results Here, we will present examples for different types of NMs and FGs including results from a currently running interlaboratory comparison (ILC) with the National Research Council of Canada (NRC) to pave the road for method standardization. Innovative aspects • Surface analysis • Performance and safety of nanomaterials • Standardization T2 - ANAKON 2023 CY - Vienna, Austria DA - 11.04.2023 KW - Engineered Nanomaterials KW - Surface group analysis KW - Optical spectroscopy KW - Quantitative NMR KW - Ligands KW - Dye KW - Particle synthesis KW - Optical Assays KW - Titration KW - Safe-by-Design KW - Nano KW - Nanosafety KW - Silica- and Polystyrene Particles PY - 2023 AN - OPUS4-59127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Rühle, Bastian A1 - Kuchenbecker, Petra A1 - Löhmann, Oliver A1 - Lindemann, Franziska A1 - Hodoroaba, Vasile-Dan T1 - Embedding and cross-sectioning as a sample preparation procedure for accurate and representative size and shape measurement of nanopowders N2 - Reliable measurement of the size of polydisperse, complex-shaped commercial nanopowders is a difficult but necessary task, e.g., for regulatory requirements and toxicity risk assessment. Suitable methods exist for the accurate characterization of the size of non-aggregated, stabilized, spherical and monodisperse nanoparticles. In contrast, industrial nanoscale powders usually require dedicated sample preparation procedures developed for the analysis method of choice. These nano-powders tend to agglomerate and/or aggregate, a behavior which in combination with an innate broad particle size distribution and irregular shape often significantly alters the achievable accuracy of the measured size parameters. The present study systematically tests two commercially available nanoscale powders using different sample preparation methods for correlative analysis by scanning electron microscopy, dynamic light scattering, Brunauer–Emmet–Teller method and differential mobility analysis. One focus was set on the sample preparation by embedding nanoparticles in carbon-based hot-mounting resin. Literature on this topic is scarce and the accuracy of the data extracted from cross sections of these particles is unclearly stated. In this paper systematic simulations on the deviation of the size parameters of well-defined series of nanoparticles with different shapes from the nominal value were carried out and the contributing factors are discussed. KW - Nanopowder KW - Electron microscopy KW - Sample preparation KW - Cross-sectioning KW - Cerium oxide KW - Zinc oxide PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593289 DO - https://doi.org/10.1038/s41598-023-51094-0 SN - 2045-2322 VL - 14 SP - 1 EP - 10 PB - Springer Nature CY - London AN - OPUS4-59328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Liaison of ISO/TC 202 Microbeam Analysis with VAMAS/TWA 37 Quantitative Microstructural 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 identification and launching corresponding VAMAS projects. The ongoing project "FIB sample processing for TEM" is presented in detail. T2 - 30th Meeting of ISO/TC 202 Microbeam Analysis CY - Berlin, Germany DA - 22.11.2023 KW - VAMAS KW - ISO/TC 202 KW - Microbeam Analysis KW - Standardisation KW - Electron microscopy KW - FIB PY - 2023 AN - OPUS4-58984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hodoroaba, Vasile-Dan ED - Hodoroaba, Vasile-Dan T1 - Liaison Report from ISO/TC 202 'Microbeam Analysis' to ISO/TC 229 'Nanotechnologies' N2 - Liaison activities within ISO/TC 202 'Microbeam Analysis' which are relevant to ISO/TC 229 'Nanotechnologies' are reported acoording to the structure defined by ISO/TC229 Nanotechnologies Liaisons Coordination Group (NLCG): new standards/documents, coordination issues, and further detailed specific information, e.g. publications, events, comments. KW - ISO/TC 229 Nanotechnologies KW - ISO/TC 202 Microbeam Analysis KW - Standardisation PY - 2023 SP - 1 EP - 3 CY - ISO, Geneva, CH AN - OPUS4-58986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - O'Connor, Daniel A1 - Evans, Alexander A1 - Balsamo, Alessandro A1 - Favres, Georges A1 - Przyklenk, Anita A1 - Bosse, Harald A1 - Phillips, Dishi T1 - European Metrology Network (EMN) for Advanced Manufacturing ─ Development of the Strategic Research Agenda (SRA) N2 - The European Commission has identified Advanced Manufacturing and Advanced Materials as two of six Key Enabling Technologies (KETs). It is considered that Metrology is a key enabler for the advancement of these KETs. Consequently, EURAMET, the association of metrology institutes in Europe, has strengthened the role of Metrology for these KETs by enabling the creation of a European Metrology Network (EMN) for Advanced Manufacturing. The EMN is comprised of National Metrology Institutes (NMIs) and Designated Institutes (DIs) from across Europe and was formally established in October 2021. The aim of the EMN is to provide a high-level coordination of European metrology activities for the Advanced Manufacturing community. The EMN itself is organized in three sections representing the major stages of the manufacturing chain: 1) Advanced Materials, 2) Smart Manufacturing Systems, and 3) Manufactured Components & Products. The EMN for Advanced Manufacturing is engaging with stakeholders in the field of Advanced Manufacturing (large companies & SMEs, industry organisations, existing networks, and academia), as well as the wider Metrology community, including Technical Committees, to provide input for the Strategic Research Agenda (SRA) on Metrology for Advanced Manufacturing. This contribution will give an overview about the first version of the SRA prepared by the EMN for Advanced Manufacturing T2 - Euspen, 23rd International Conference & Exhibitio CY - Copenhagen, Danmark DA - 12.06.2023 KW - European Metrology Network (EMN) KW - Advanced Manufacturing KW - Metrology KW - Strategic Research Agenda (SRA) PY - 2023 SP - 363 EP - 364 AN - OPUS4-59196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinekamp, Christian A1 - Kneiske, Sönke A1 - Guilherme Buzanich, Ana A1 - Ahrens, Mike A1 - Braun, Thomas A1 - Emmerling, Franziska T1 - A fluorolytic sol-gel route to access an amorphous Zr fluoride catalyst: A useful tool for C-F bond activation N2 - A route to a ZrF4 catalyst active in room temperature Friedel–Crafts and dehydrofluorination reactions was developed via a fluorolytic sol–gel route, which was followed by a postfluorination step using a stream of CHClF2. The behaviour of different Zr(IV) precursors in a sol–gel reaction with anhydrous isopropanol/HF solution was investigated. The subsequent post-fluorination step was optimised in its temperature ramp and confirmed the necessity of a fluorination of the generated xerogels to obtain catalytic activity. The process is discussed in the context of the analysis of the materials using Brunauer–Emmett–Teller analysis (BET), powder X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The local structure of the amorphous catalyst was elucidated by extended X-ray absorption fine structure spectroscopy (EXAFS). KW - Catalysis KW - Heterogeneous catalysis KW - C-F bond activation KW - Postfluorination PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593433 DO - https://doi.org/10.1039/D3CY01439H SN - 2044-4761 SP - 1 EP - 8 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella T1 - (Nano-)Partikel-Tracking-Analyse (PTA/NTA) N2 - Einführung in die Partikelgrößenbestimmung von (Nano)Materialien mittels NTA/PTA. Normative Grundlagen (ISO 19430:2016 und ASTM E2834), Messprinzip, Messgeräte, Einflussfaktoren und Besonderheiten, Implementierung, Informationsgehalt der Daten, Reporting. T2 - BAM Akademie: Info-Tage "NANO OR NOT NANO" CY - Online meeting DA - 16.02.2023 KW - Partikelgrößenbestimmung KW - Partikelkonzentration KW - Nano KW - Standardisierung KW - Brownsche Molekularbewegung KW - Lichtstreuung PY - 2023 AN - OPUS4-59132 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osipova, Viktoriia A1 - Tavernaro, Isabella A1 - Resch-Genger, Ute T1 - Incorporation of near-infrared light emitting chromium (III) complexes into silica nanoparticles and spectroscopic characterization N2 - In recent years, chromium (III) complexes have received a lot of attention as novel near-infrared (NIR) emitters triggered by the report on the first molecular ruby Cr(ddpd)2(BF4)3 with a high photoluminescence quantum yield of 13.7% of its near infrared (NIR) emission band and a long luminescence lifetime of 1.122 ms at room temperature.[1] However, in an oxygen-containing environment, the photoluminescence quantum yields and luminescence lifetimes of these chromium(III) complexes show only very small values. This hampers their application as NIR luminescence labels. This application, that cannot be tackled by conventional deoxygenating approaches, requires suitable strategies to protect the luminescence of the chromium(III) complexes from oxygen quenching. An elegant approach to reduce the undesired luminescence quenching by triplet oxygen explored by us presents the incorporation of these chromium(III) complexes into different types of amorphous, non-porous silica nanoparticles, that can be simply surface functionalized, e.g., with targeting ligands and/or other sensor molecules. In this work, as first proof-of-concept experiments, a set of chromium (III) complexes constituting of different ligands and counter anions, were embedded into the core of silica nanoparticles. Subsequently, the optical properties of the resulting luminescent silica nanoparticles were spectroscopically assessed by steady state and time-resolved luminescence spectroscopy. First results of time-resolved luminescence measurements confirm our design concept of nanoscale NIR emissive Cr(III) complex-based reporters T2 - Projekttreffen Nile-Chrome 2.0 CY - Mainz, Germany DA - 11.12.2023 KW - Cr(III) complex KW - NIR KW - Luminescence KW - Nano KW - Silica KW - Lifetime KW - Quantum Yields KW - Particle Synthesis KW - Sensors KW - Probe KW - Surface Group Analysis PY - 2023 AN - OPUS4-59149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Scholtz, Lena A1 - Resch-Genger, Ute T1 - Behind the Paper - Dual color pH probes made from silica and polystyrene nanoparticles and their performance in cell studies N2 - In this contribution we highlight the importance of comparison for scientific research while developing a new, functional pH sensor system, and the valuable insights this can provide. KW - Dye KW - Optical Spectroscopy KW - pH probe KW - Silica and Polystyrene Particles KW - Nano KW - Surface groups KW - Safe-by-Design KW - Cell studies KW - Sensors KW - Particle Synthesis KW - Fluorescence PY - 2023 UR - https://communities.springernature.com/posts/dual-color-ph-probes-made-from-silica-and-polystyrene-nanoparticles-and-their-performance-in-cell-studies SP - 1 EP - 2 PB - Springer Nature CY - London AN - OPUS4-59150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tavernaro, Isabella A1 - Osipova, Viktoriia A1 - Srivastava, Priyanka A1 - Huang, Zixuan A1 - Merei, Rabih A1 - Resch-Genger, Ute T1 - Design of Fluorescent, Amorphous Silica-NPs and their Versatile Use in Sensing Applications N2 - Surface functionalized silica nanoparticles (SiO2-NP) gained great interest in the life and material sciences, as they can be used e.g. as drug carriers, fluorescent sensors, and multimodal labels in bioanalytical assays and imaging applications. They are highly stable, are easily produced and modified on a large scale at low cost and can be labeled or stained with a multitude of sensor dyes. These dye modified particle conjugates have several advantages as compared to conventional molecular probes like enhanced brightness, ease of designing ratiometric systems by combining analyte-sensitive and inert reference dyes, and increased photostability. Moreover, stained nanoparticles can enable the use of hydrophobic dyes in aqueous environments. Here we present our work on multicolored sensors for the measurement of pH, oxygen and saccharides utilizing amorphous SiO2 NPs. T2 - Focus Area Day Analytical Sciences 2023 CY - Berlin, Germany DA - 20.04.2023 KW - Amorphous silica particles KW - Particle Synthesis KW - Nano KW - Ratiometric Sensors KW - Fluorescence KW - pH probe KW - Dye PY - 2023 AN - OPUS4-59151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Favres, Georges A1 - O'Connor, Daniel A1 - Balsamo, Alessandro A1 - Evans, Alexander A1 - Castro, Fernando A1 - Przyklenk, Anita A1 - Bosse, Harald T1 - European Metrology Network (EMN) for Advanced Manufacturing N2 - The European Commission has identified Advanced Manufacturing and Advanced Materials as two of six Key Enabling Technologies (KETs). By fully utilizing these KETs, advanced and sustainable economies will be created. It is considered that Metrology is a key enabler for the advancement of these KETs. EURAMET, the association of metrology institutes in Europe, has strengthened the role of Metrology for these KETs by enabling the creation of a European Metrology Network for Advanced Manufacturing. The EMN is made up of National Metrology Institutes (NMIs) and Designated Institutes (DIs) from across Europe and was formally established in October 2021. The EMN aims to provide a high-level coordination of European metrology activities for the Advanced Materials and Advanced Manufacturing community. The EMN itself is organized in three sections representing the major stages of the manufacturing chain: 1) Advanced Materials, 2) Smart Manufacturing Systems, and 3) Manufactured Components & Products. The EMN for Advanced Manufacturing is engaging with stakeholders in the field of Advanced Manufacturing and Advanced Materials (Large companies & SMEs, industry organisations, existing networks, and academia), as well as the wider metrology community (including TCs) to provide input for the preparation of a Strategic Research Agenda (SRA) for Metrology for Advanced Manufacturing. This presentation will describe the progress in the development of the SRA by the EMN for Advanced Manufacturing. The metrology challenges identified across the various key industrial sectors, which utilise Advanced Materials and Advanced Manufacturing will be presented. The EMN for Advanced Manufacturing is supported by the project JNP 19NET01 AdvManuNet. T2 - 21st International Metrology Congress, CIM 2023 CY - Lyon (Chassieu), France DA - 07.03.2023 KW - Advanced Materials KW - EMN KW - European Metrology Network for Advanced Manufacturing, Strategic Research Agenda KW - SRA PY - 2023 AN - OPUS4-59208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - SEM/EDS as THE Versatile and Powerful Tool for Micro and Nano Analysis N2 - The basic principles of generation of electrons and X-rays and the operation of SEM/EDS instruments are presented. Examples, recent successes and challenges in the analysis of nano-structures are given. Multi-method analytical approaches with the focus on imaging the nanoscale are highlighted. Details on the sample preparation and persepective on the automated analysis (sample preparation, measurement, data analyis and storage) are given. Metrological aspects, standardisation, and reference materials are also emphasized by examples. T2 - Training Course Metrological Determination of Micro and Nano Contaminants in Food CY - Berne, Switzerland DA - 05.09.2023 KW - SEM KW - EDS KW - Microanalysis KW - Nanoanalysis KW - Imaging PY - 2023 UR - https://www.sem.admin.ch/metas/en/home/dl/kurs_uebersicht/micro_nano_contaminants_in_food.html AN - OPUS4-58188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sun, Yijuan A1 - Gawlitza, Kornelia A1 - Valderrey, Virginia A1 - Bell, Jérémy A1 - Rurack, Knut T1 - Polymerizable BODIPY probe crosslinker for the molecularly imprinted polymer-based detection of organic carboxylates via fluorescence N2 - This contribution reports the development of a polymerizable BODIPY-type fluorescent probe targeting small-molecule carboxylates for incorporation into molecularly imprinted polymers (MIPs). The design of the probe crosslinker includes a urea recognition site p-conjugated to the 3-position of the BODIPY core and two methacrylate moieties. Titration experiments with a carboxylate-expressing antibiotic, levofloxacin (LEVO), showed a blue shift of the absorption band as well as a broadening and decrease in emission, attributed to hydrogen bonding between the probe’s urea group and the carboxylate group of the antibiotic. Using this probe crosslinker, core–shell particles with a silica core and a thin MIP shell were prepared for the detection of LEVO. The MIP exhibited highly selective recognition of LEVO, with an imprinting factor of 18.1 compared to the non-imprinted polymer. Transmission electron microscopy confirmed the core–shell structure and spectroscopic studies revealed that the receptor’s positioning leads to a unique perturbation of the polymethinic character of the BODIPY chromophore, entailing the favourable responses. These features are fully preserved in the MIP, whereas no such response was observed for competitors such as ampicillin. The sensory particles allowed to detect LEVO down to submicromolar concentrations in dioxane. We have developed here for the first time a BODIPY probe for organic carboxylates and incorporated it into polymers using the imprinting technique, paving the way for BODIPY-type fluorescent MIP sensors. KW - Fluorescence KW - BODIPY probe KW - Molecularly Imprinted Polymers KW - Sensor Materials KW - Dyes KW - Water analysis KW - Advanced materials PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598629 DO - https://doi.org/10.1039/D3MA00476G SP - 1 EP - 11 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59862 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Probenpräparation für AFM-basierte Untersuchungsverfahren N2 - Adapted and advanced sample preparation of semiconductor layer systems with the focused ion beam for AFM-based test methods N2 - Der vorliegende Vortrag gibt einen Überblick über Probenpräparationen mit der Focused Ion Beam (FIB) für AFM-basierte Untersuchungsverfahren. Anhand zweier Beispiele wird gezeigt, wie ionenstrahlpolierte Lamellen aus Halbleiter-Schichtsystemen elektrisch leitfähig auf Substrate platziert werden, so dass in-situ und in-operando Messungen mit Scanning Microwave Microscope (SMM) bzw. Spectroscopic infrared scanning near-field optical microscope (IR-SNOM) durchgeführt werden können. T2 - 15. Berlin-Brandenburger Präparatorentreffen CY - Potsdam/Golm, Germany DA - 11.04.2019 KW - Focused Ion Beam KW - AFM based test methods KW - Sample preparation KW - Semiconductor materials KW - Layer system PY - 2019 AN - OPUS4-47784 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ciornii, Dmitri A1 - Altmann, Korinna A1 - Hodoroaba, Vasile-Dan T1 - Getting reliable data on microplastic detection methods by means of ILC N2 - There is an urgent demand for reliable data on microplastic analysis, particularly on its physico-chemical properties as well as validated methodology to obtain such data. Through interlaboratory comparisons (ILCs) it becomes possible to assess accuracy and precision of methods by involving many laboratories around the world. At BAM, my tasks focused around organisation of an ILC on physico-chemical characterisation of microplastic detection methods under the international pre-standardisation platform VAMAS (www.vamas.org/twa45/) as Project 2 “Development of standardized methodologies for characterisation of microplastics with microscopy and spectroscopy methods” under the Technical Working Area TWA 45 “Micro and Nano Plastics in the Environment”. With a proud number of 84 participants this ILC is able to provide superior statistical results. Thermoanalytical (Py-GC/MS and TED-GC/MS) and vibrational (µ-IR and µ-Raman) methods were asked for identification and quantification of microplastic test samples according to mass or particle number. Preliminary results indicate which methods show a higher accuracy and precision and reveal some sample preparation ideas which work best for microplastics characterisation. At the end of the ILC an overall plausibility of the results will be assessed. T2 - CUSP Early Career Researchers Meeting CY - Online meeting DA - 21.11.2023 KW - Micro- and Nanoplastics KW - Interlaboratory comparison KW - Microplastic reference materials PY - 2023 AN - OPUS4-59056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - López-Iglesias, C. A1 - Markovina, A. A1 - Nirmalananthan-Budau, N. A1 - Resch-Genger, Ute A1 - Klinger, D. T1 - Optically monitoring the microenvironment of a hydrophobic cargo in amphiphilic nanogels: influence of network composition on loading and release N2 - Amphiphilic nanogels (ANGs) are promising carriers for hydrophobic cargos such as drugs, dyes, and catalysts. Loading content and release kinetics of these compounds are controlled by type and number of hydrophobic groups in the amphiphilic copolymer network. Thus, understanding the interactions between cargo and colloidal carrier is mandatory for a tailor-made and cargo-specific ANG design. To systematically explore the influence of the network composition on these interactions, we prepared a set of ANGs of different amphiphilicity and loaded these ANGs with varying concentrations of the solvatochromic dye Nile Red (NR). Here, NR acts as a hydrophobic model cargo to optically probe the polarity of its microenvironment. Analysis of the NR emission spectra as well as measurements of the fluorescence quantum yields and decay kinetics revealed a decrease in the polarity of the NR microenvironment with increasing hydrophobicity of the hydrophobic groups in the ANG network and dye–dye interactions at higher loading concentrations. At low NR concentrations, the hydrophobic cargo NR is encapsulated in the hydrophobic domains. Increasing NR concentrations resulted in probe molecules located in a more hydrophilic environment, i.e., at the nanodomain border, and favored dye–dye interactions and NR aggregation. These results correlate well with release experiments, indicating first NR release from more hydrophilic network locations. Overall, our findings demonstrate the importance to understand carrier–drug interactions for efficient loading and controlled release profiles in amphiphilic nanogels. KW - Particle KW - Energy transfer KW - Limit of detection KW - Polymer KW - Luminescence KW - Quantitative spectroscopy KW - Nano KW - Quantum yield KW - Lifetime KW - Quality assurance KW - Dye KW - Probe KW - Sensor KW - Nile Red PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601603 DO - https://doi.org/10.1039/d4nr00051j SN - 2040-3364 IS - 16 SP - 9525 EP - 9535 PB - The Royal Society of Chemistry AN - OPUS4-60160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Salzmann, Christoph A1 - Heilmann, Maria T1 - Ongoing VAMAS interlaboratory comparisons on nanoparticles size and shape as pre standardisation projects for harmonized measurements 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 - 2024 Spring Meeting of the European Materials Research Society (E-MRS) CY - Strasbourg, France DA - 27.05.2024 KW - VAMAS KW - Interlaboratory comparison KW - Electron microscopy KW - Particle size distribution KW - Article concentration PY - 2024 AN - OPUS4-60184 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Tchetgnia Ngassam, Ines Leana A1 - Olonade, K. A. A1 - Mbugua, R. A1 - Kühne, Hans-Carsten T1 - Plant based chemical admixtures – potentials and effects on the performance of cementitious materials N2 - While today, engineers can choose from a wide range of rheology modifying admixtures, in some parts of the world, these are difficult to access, due to their complex processing. However, alternatives can be bio‐based polymers such as polysaccharides from various sources. These are easily accessible all over the world, do not demand for complicated processing, and typically they are more sustainable than many established materials, which are crude oil‐based. The paper presents the effects of acacia gum, cassava starch and the gum of triumfetta pendrata A. Rich on the rheological performance of cementitious systems. It is shown that acacia gum can be as efficient as polycarboxylate based superplasticisers, cassava starch can reduce the yield stress slightly with little effect on the plastic viscosity, and the gum of triumfet ta pendrata A. Rich increases the thixotropy of cement pastes with plasticizing polymers significantly. KW - Polysaccharides KW - Rheology KW - Cement KW - Chemical admixtures KW - Bio-based concrete PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-476748 DO - https://doi.org/10.21809/rilemtechlett.2018.83 VL - 3 SP - 124 EP - 128 PB - RILEM S.A.R.L. CY - Paris AN - OPUS4-47674 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mech, A. A1 - Wohlleben, W. A1 - Ghanem, A. A1 - Hodoroaba, Vasile-Dan A1 - Weigel, S. A1 - Babick, F. A1 - Brüngel, R. A1 - Friedrich, C. M. A1 - Rasmussen, K. A1 - Rauscher, H. T1 - Nano or Not Nano? A Structured Approach for Identifying Nanomaterials According to the European Commission’s Definition N2 - Identifying nanomaterials (NMs) according to European Union Legislation is challenging, as there is an enormous variety of materials, with different physico-chemical properties. The NanoDefiner Framework and its Decision Support Flow Scheme (DSFS) allow choosing the optimal method to measure the particle size distribution by matching the material properties and the performance of the particular measurement techniques. The DSFS leads to a reliable and economic decision whether a material is an NM or not based on scientific criteria and respecting regulatory requirements. The DSFS starts beyond regulatory requirements by identifying non-NMs by a proxy Approach based on their volume-specific surface area. In a second step, it identifies NMs. The DSFS is tested on real-world materials and is implemented in an e-tool. The DSFS is compared with a decision flowchart of the European Commission’s (EC) Joint Research Centre (JRC), which rigorously follows the explicit criteria of the EC NM definition with the focus on identifying NMs, and non-NMs are identified by exclusion. The two approaches build on the same scientific basis and measurement methods, but start from opposite ends: the JRC Flowchart starts by identifying NMs, whereas the NanoDefiner Framework first identifies non-NMs. KW - Classification KW - Definition KW - Identification KW - Nanomaterials KW - Particle size KW - Regulation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510917 DO - https://doi.org/10.1002/smll.202002228 SN - 1613-6829 SP - 2002228-1 EP - 2002228-16 PB - Wiley-VCH CY - Weinheim AN - OPUS4-51091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Hörenz, Christoph A1 - Durande, B. A1 - Taché, O. A1 - Bartczak, D. A1 - Cuello-Nuñez, S. A1 - Ábad-Alvaro, I. A1 - Goenaga-Infante, H. 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 - CONF A1 - Hodoroaba, Vasile-Dan A1 - Cios, G. A1 - Tokarski, T. A1 - Mansfeld, Ulrich A1 - Ortel, Erik A1 - Mielke, Johannes A1 - Pellegrino, F. A1 - Maurino, V. T1 - Towards 3D understanding of non spherical nanoparticles by Transmission Kikuchi Diffraction (TKD) for improved particle size distribution by electron microscopy N2 - In this paper one refined approach is applied to determine the exact orientation of bipyramidal TiO2 nanoparticles prepared with good dispersion as almost isolated particles on a carbon TEM grid. The advantages of the recently developed high-throughput Transmission Kikuchi Diffraction (TKD) are used to identify quickly and reliably the geometrical orientation of the crystalline TiO2 nanoparticle bipyramids (anatase) on a statistically relevant number of particles. T2 - Microscopy and Microanalysis 2020 CY - Online meeting DA - 03.08.2020 KW - Nanoparticles KW - Transmission Kikuchi Diffraction (TKD) KW - TiO2 KW - 3D KW - Electron microscopy PY - 2020 AN - OPUS4-51113 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Rühle, Bastian T1 - Towards automated electron microscopy image segmentation for nanoparticles of complex shape by convolutional neural networks N2 - In this contribution different ways are explored with the aim to generate suitable training data for ‘non-ideal’ samples using various approaches, e.g., computer-generated images or unsupervised learning algorithms such as generative adversarial networks (GANs). We used these data to train simple CNNs to produce segmentation masks of SEM images and tested the trained networks on real SEM images of complex nanoparticle samples. The novel use of CNN for the automated analysis of the size of nanoparticles of complex shape and with a high degree of agglomeration has proved to be a promising tool for the evaluation of particle size distribution on a large number of constituent particles. Further development and validation of the preliminary model, respectively larger training and validation data sets are necessary. T2 - Microscopy and Microanalysis 2020 CY - Online meeting DA - 03.08.2020 KW - Nanoparticles KW - Automatisation KW - Image segmentation KW - Convolutional neural networks KW - Electron microscopy PY - 2020 AN - OPUS4-51114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hörenz, Christoph T1 - Preparation of Nanoparticulate Samples for Electron Microscopy N2 - This presentation addresses the importance of proper sample preparation to obtain suitable samples for electron microscopic measurements. The objective as well as the requirements are discussed. Further, different sample deposition methods for various types of nanoparticulate samples are shown. T2 - nPSize Web Conference CY - Online meeting DA - 23.07.2020 KW - Nanoparticles KW - Electron microscopy KW - Sample preparation KW - Particle size distribution KW - Particle number concentration PY - 2020 AN - OPUS4-51047 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stawski, Tomasz A1 - Besselink, R. A1 - Chatzipanagis, K. A1 - Hövelmann, J. A1 - Benning, L. G. A1 - Van Driessche, E. S. T1 - Nucleation Pathway of Calcium Sulfate Hemihydrate (Bassanite) from Solution: Implications for Calcium Sulfates on Mars N2 - CaSO4 minerals (i.e., gypsum, anhydrite, and bassanite) are widespread in natural and industrial environments. During the last several years, a number of studies have revealed that nucleation in the CaSO4–H2O system is nonclassical, where the formation of crystalline phases involves several steps. Based on these recent insights, we have formulated a tentative general model for calcium sulfate precipitation from solution. This model involves primary species that are formed through the assembly of multiple Ca2+ and SO42– ions into nanoclusters. These nanoclusters assemble into poorly ordered (i.e., amorphous) hydrated aggregates, which in turn undergo ordering into coherent crystalline units. The thermodynamic (meta)stability of any of the three CaSO4 phases is regulated by temperature, pressure, and ionic strength, with gypsum being the stable form at low temperatures and low-to-medium ionic strengths and anhydrite being the stable phase at high temperatures and at lower temperature for high salinities. Bassanite is metastable across the entire phase diagram but readily forms as the primary phase at high ionic strengths across a wide range of temperatures and can persist up to several months. Although the physicochemical conditions leading to bassanite formation in aqueous systems are relatively well established, nanoscale insights into the nucleation mechanisms and pathways are still lacking. To fill this gap and to further improve our general model for calcium sulfate precipitation, we conducted in situ scattering measurements at small-angle X-ray scattering and wide-angle X-ray scattering and complemented these with in situ Raman spectroscopic characterization. Based on these experiments, we show that the process of formation of bassanite from aqueous solutions is very similar to the formation of gypsum: it involves the aggregation of small primary species into larger disordered aggregates, only from which the crystalline phase develops. These data thus confirm our general model of CaSO4 nucleation and provide clues to explain the abundant occurrence of bassanite on the surface of Mars (and not on the surface of Earth). KW - Gypsum' SAXS KW - Calcium sulfate KW - Bassanite KW - Nucleation PY - 2020 DO - https://doi.org/10.1021/acs.jpcc.0c01041 VL - 124 IS - 15 SP - 8411 EP - 8422 PB - American Chemical Society AN - OPUS4-50849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sattari, S. A1 - Beyranvand, S. A1 - Soleimani, K. A1 - Rassoli, K. A1 - Salahi, P. A1 - Donskyi, Ievgen A1 - Shams, A. A1 - Unger, Wolfgang A1 - Yari, A. A1 - Farjanikish, G. A1 - Nayebzadeh, H. A1 - Adeli, M. T1 - Boronic Acid-Functionalized Two-Dimensional MoS2 at Biointerfaces N2 - While noncovalent interactions at two-dimensional nanobiointerfaces are extensively investigated, less knowledge about covalent interactions at this interface is available. In this work, boronic acid-functionalized 2D MoS2 was synthesized and its covalent multivalent interactions with bacteria and nematodes were investigated. Polymerization of glycidol by freshly exfoliated MoS2 and condensation of 2,5-thiophenediylbisboronic acid on the produced platform resulted in boronic acid-functionalized 2D MoS2. The destructive interactions between 2D MoS2 and bacteria as well as nematodes were significantly amplified by boronic acid functional groups. Because of the high antibacterial and antinematodal activities of boronic acid-functionalized 2D MoS2, its therapeutic efficacy for diabetic wound healing was investigated. The infected diabetic wounds were completely healed 10 days after treatment with boronic acid-functionalized 2D MoS2, and a normal structure for recovered tissues including different layers of skin, collagen, and blood vessels was detected. KW - XPS KW - Boronic acid-functionalized 2D MoS2 KW - Covalent interactions KW - Bacteria KW - Nanobiointerfaces PY - 2020 DO - https://doi.org/10.1021/acs.langmuir.0c00776 VL - 36 IS - 24 SP - 6706 EP - 6715 PB - ACS American Chemical Society AN - OPUS4-51024 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 - JOUR A1 - Dittmann, Daniel A1 - Eisentraut, Paul A1 - Goedecke, Caroline A1 - Wiesner, Yosri A1 - Jekel, M A1 - Ruhl, A S A1 - Braun, Ulrike T1 - Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine N2 - The adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation. KW - Aktivkohle KW - TED-GC/MS KW - Adsorption KW - Thermoanalytik PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506946 DO - https://doi.org/10.1038/s41598-020-63481-y VL - 10 IS - 1 SP - 6695 PB - Nature Publishing Group AN - OPUS4-50694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -