TY - JOUR A1 - Vogel, Christian A1 - Helfenstein, J. A1 - Massey, M. A1 - Sekine, R. A1 - Kretzschmar, R. A1 - Beiping, L. A1 - Peter, T. A1 - Chadwick, O. A1 - Tamburini, F. A1 - Rivard, C. A1 - Herzel, Hannes A1 - Adam, Christian A1 - Pradas del Real, A. A1 - Castillo-Michel, H. A1 - Zuin, L. A1 - Wang, D. A1 - Félix, R. A1 - Lassalle-Kaiser, B. A1 - Frossard, E. T1 - Microspectroscopy reveals dust-derived apatite grains in acidic, highly-weathered Hawaiian soils N2 - Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic Gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradient were analyzed with bulk (X-ray diffraction and P K-edge X-ray absorption near edge structure) and microscale (X-ray fluorescence, P K-edge X-ray absorption near edge structure, and Raman) analysis methods. In the wettest soils, apatite grains ranging from 5 to 30 μm in size were co-located at the micro-scale with quartz, a known continental dust indicator suggesting recent atmospheric deposition. In addition to co-location with quartz, further evidence of dust-derived P included backward trajectory modeling indicating that dust particles could be brought to Hawaii from the major global dust-loading areas in central Asia and northern Africa. Although it is not certain whether the individual observed apatite grains were derived from long-distance transport of dust, or from local dust sources such as volcanic ash or windblown fertilizer, these observations offer direct evidence that P-containing minerals have reached surface layers of highly-weathered grassland soils through atmospheric deposition. KW - Phosphorus KW - soil KW - microspectroscopy KW - Raman spectroscopy KW - XANES spectroscopy KW - x-ray diffraction PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511522 DO - https://doi.org/10.1016/j.geoderma.2020.114681 SN - 0166-0918 SN - 1872-6259 VL - 381 SP - 114681-1 EP - 114681-11 PB - Elsevier CY - Amsterdam AN - OPUS4-51152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagl, Dorothee A1 - Szymoniak, Paulina A1 - Hodoroaba, Vasile-Dan A1 - Sturm, Heinz T1 - The effect of boehmite nanoparticles (gamma‐AlOOH) on nanomechanical and thermomechanical properties correlated to crosslinking density of epoxy N2 - We show that complex physical and chemical interactions between boehmite nanoparticles and epoxy drastically affect matrix properties, which in the future will provide tuning of material properties for further optimization in applications from automotive to aerospace. We utilize intermodulation atomic force microscopy (ImAFM) for probing local stiffness of both particles and polymer matrix. Stiff particles are expected to increase total stiffness of nanocomposites and the stiffness of polymer should remain unchanged. However, ImAFM revealed that stiffness of matrix in epoxy/boehmite nanocomposite is significantly higher than unfilled epoxy. The stiffening effect of the boehmite on epoxy also depends on the particle concentration. To understand the mechanism behind property alteration induced by boehmite nanoparticles, network architecture is investigated using dynamic mechanical thermal analysis (DMTA). It was revealed that although with 15 wt% boehmite nanoparticles the modulus at glassy state increases, crosslinking density of epoxy for this composition is drastically low. KW - Crosslinking density KW - Epoxy KW - Intermodulation KW - Atomic force microscopy KW - Nanomechanical properties KW - Boehmite nanoparticles PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-476050 DO - https://doi.org/10.1016/j.polymer.2018.12.054 SN - 0032-3861 SN - 1873-2291 VL - 164 SP - 174 EP - 182 PB - Elsevier AN - OPUS4-47605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Sekine, R. A1 - Steckenmesser, D. A1 - Lombi, E. A1 - Herzel, Hannes A1 - Zuin, L. A1 - Wang, D. A1 - Felix, R. A1 - Adam, Christian T1 - Combining diffusive gradients in thin films (DGT) and spectroscopic techniques for the determination of phosphorus species in soils N2 - A wide range of methods are used to estimate the plant-availability of soil phosphorus (P). Published research has shown that the diffusive gradients in thin films (DGT) technique has a superior correlation to plant-available P in soils compared to standard chemical extraction tests. In order to identify the plantavailable soil P species, we combined DGT with infrared and P K- and L2,3-edge X-ray adsorption near edge structure (XANES) spectroscopy. This was achieved by spectroscopically investigating the dried binding layer of DGT devices after soil deployment. All three spectroscopic methods were able to distinguish between different kinds of phosphates (poly-, trimeta-, pyro- and orthophosphate) on the DGT binding layer. However, infrared spectroscopy was most sensitive to distinguish between different types of adsorbed inorganic and organic phosphates. Furthermore, intermediates of the time-resolved hydrolysis of trimetaphosphate in soil could be analyzed. KW - Phosphorus plant-availability KW - X-ray adsorption near-edge structure (XANES) spectroscopy KW - Infrared spectroscopy KW - Diffusive gradients in thin films (DGT) PY - 2019 DO - https://doi.org/10.1016/j.aca.2019.01.037 SN - 0003-2670 VL - 1057 SP - 80 EP - 87 PB - Elsevier AN - OPUS4-47471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Goedecke, Caroline A1 - Dittmann, Daniel A1 - Eisentraut, Paul A1 - Wiesner, Yosri A1 - Schartel, Bernhard A1 - Klack, Patrick A1 - Braun, Ulrike T1 - Evaluation of thermoanalytical methods equipped with evolved gas analysis for the detection of microplastic in environmental samples N2 - Microplastic particles are currently detected in almost all environmental compartments. The results of detection vary widely, as a multitude of very different methods are used with very different requirements for analytical validity. In this work four thermoanalytical methods are compared and their advantages and limitations are discussed. One of them is thermal extraction-desorption gas chromatography mass spectrometry (TED-GC/MS), an analysis method for microplastic detection that has become established in recent years. In addition, thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS) were applied, two methods that are less common in this field but are still used in other research areas. Finally, microscale combustion calorimeter (MCC) was applied, a method not yet used for microplastic detection. The presented results are taken from a recently published interlaboratory comparison test by Becker et al. (2020). Here a reference material consisting of suspended matter and specified added polymer masses was examined, and only the results of the recoveries were presented. In the present paper, however, the results for the individual polymers are discussed in detail and individual perspectives for all instruments are shown. It was found that TED-GC/MS is the most suitable method for samples with unknown matrix and unknown, variable kinds and contents of microplastic. TGA-FTIR is a robust method for samples with known matrix and with defined kinds of microplastic. TGA-MS may offer a solution for the detection of PVC particles in the future. MCC can be used as a very fast and simple screening method for the identification of a potential microplastic load of standard polymers in unknown samples. KW - Microplastic KW - TED-GC/MS KW - TGA-MS KW - TGA-FTIR KW - MCC KW - Thermal analysis PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516687 DO - https://doi.org/10.1016/j.jaap.2020.104961 VL - 152 SP - 104961 PB - Elsevier B.V. AN - OPUS4-51668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fink, Friedrich A1 - Emmerling, Franziska A1 - Falkenhagen, Jana T1 - Identification and Classification of Technical Lignins by means of Principle Component Analysis and k-Nearest Neighbor Algorithm N2 - The characterization of technical lignins is a key step for the efficient use and processing of this material into valuable chemicals and for quality control. In this study 31 lignin samples were prepared from different biomass sources (hardwood, softwood, straw, grass) and different pulping processes (sulfite, Kraft, organosolv). Each lignin was analysed by attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy. Statistical analysis of the ATR-FT-IR spectra by means of principal component analysis (PCA) showed significant differences between the lignins. Hence, the samples can be separated by PCA according to the original biomass. The differences observed in the ATR-FT-IR spectra result primarily from the relative ratios of the p-hydroxyphenyl, guaiacyl and syringyl units. Only limited influence of the pulping process is reflected by the spectral data. The spectra do not differ between samples processed by Kraft or organosolv processes. Lignosulfonates are clearly distinguishable by ATR-FT-IR from the other samples. For the classification a model was created using the k-nearest neighbor (k NN) algorithm. Different data pretreatment steps were compared for k=1…20. For validation purposes, a 5-fold cross-validation was chosen and the different quality criteria Accuracy (Acc), Error Rate (Err), Sensitivity (TPR) and specificity (TNR) were introduced. The optimized model for k=4 gives values for Acc = 98.9 %, Err = 1.1 %, TPR = 99.2 % and TNR = 99.6 %. KW - Classification KW - PCA KW - K-nearest neighbor KW - FT-IR KW - Technical lignin PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533855 DO - https://doi.org/10.1002/cmtd.202100028 VL - 1 IS - 8 SP - 350 EP - 396 PB - Wiley-VCH GmbH AN - OPUS4-53385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Falkenhagen, Jana A1 - Panne, Ulrich A1 - Hiller, W. A1 - Gruendling, T. A1 - Staal, B. A1 - Lang, C. A1 - Lamprou, A. T1 - Simultaneous characterization of poly(acrylic acid) andpolysaccharide polymers and copolymers N2 - Copolymer products that result from grafting acrylic acid and other hydrophilicmonomers onto polysaccharides have recently gained significant interest in researchand industry. Originating from renewable sources, these biodegradable, low toxicity,and polar copolymer products exhibit potential to replace polymers from fossil sourcesin several applications and industries. The methods usually employed to character-ize these copolymers are, however, quite limited, especially for the measurement ofbulk properties. With more sophisticated applications, for example, in pharmaceu-tics requiring a more detailed analysis of the chemical structure, we describe a newapproach for this kind of complex polymers. Our approach utilizes chromatographyin combination with several detection methods to separate and characterize reactionproducts of the copolymerization of acrylic acid and chemically hydrolyzed starch.These samples consisted of a mixture of homopolymer poly (acrylic acid), homopoly-mer hydrolyzed starch, and – in a lower amount – the formed copolymers. Several chro-matographic methods exist that are capable of characterizing either poly (acrylic acid)or hydrolyzed starch. In contrast, our approach offers simultaneous characterization ofboth polymers. The combination of LC and UV/RI offered insight into the compositionand copolymer content of the samples. Size exclusion chromatography experimentsrevealed the molar mass distribution of homopolymers and copolymers. FTIR inves-tigations confirmed the formation of copolymers while ESI-MS gave more details onthe end groups of hydrolyzed starches and poly (acrylic acids). Evidence of copolymerstructures was obtained through NMR measurements. Finally, two-dimensional chro-matography led to the separation of the copolymers from both homopolymers as wellas the additional separation of sodium clusters. The methods described in this work area powerful toolset to characterize copolymerization products of hydrolyzed starch andpoly(acrylic acid). Together, our approach successfully correlates the physicochemicalproperties of such complex mixtures with their actual composition. KW - 2D chromatography KW - LC-MS KW - SEC KW - Renewable copolymers KW - Grafting PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508873 DO - https://doi.org/10.1002/ansa.202000044 SP - 1 EP - 12 PB - Wiley-VCH Verlag-GmbH&Co. KGaA CY - Weinheim AN - OPUS4-50887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao A1 - Hoffmann, Volker A1 - Morcillo, Dalia A1 - Agudo Jácome, Leonardo A1 - Leonhardt, Robert A1 - Winckelmann, Alexander A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique T1 - Detection of aluminum deposition on the cathodes of aged lithium ion batteries by GD-OES N2 - The use of renewable energy sources, electromobility, and portable electronics relies on lithium-ion batteries (LIBs). However, one detrimental effect, which can result in significant performance loss, is the corrosion of the current collectors caused by the aging mechanisms, especially in high-energy-density batteries Glow discharge optical emission spectroscopy (GD-OES) provides depth profile analysis through sputtering using argon plasma, which enables the analysis of the corrosion behavior at different depths of the cathodes. T2 - GD-OES Anwendertreff CY - Dresden, Germany DA - 26.27.2022 KW - glow KW - discharge KW - optical KW - emission KW - spectroscopy PY - 2022 AN - OPUS4-56105 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Falkenhagen, Jana T1 - Combined impact of UV radiation and nitric acid (HNO3) on HDPE jerrycans – comparison of outdoor and lab test N2 - A damaging action of HNO3-55% only occurs in combination with its decomposition into nitrous gases, which can be caused by UV radiation. In a laboratory test, transparent HDPE jerrycans have been exposed to both UV radiation and 55 wt-% nitric acid solution at (41 ± 2)°C, for up to 20 days. For comparison, UV radiant exposure (21 days) and nitric acid exposure (up to 6 weeks) were performed separately, at nearly equal temperatures. The respective damages are compared with FTIR spectroscopy in ATR and HT-gel permeation chromatography (GPC) on a molecular level and with hydraulic internal pressure testing as a component test. For the used jerrycans, relevant oxidation can only be found after the combined exposure. The gradual increase in oxidative damage shows the good reproducibility of the lab exposure. The decomposition of nitric acid into nitrous gases by UV radiation – as well as the jerrycan oxidation – is also observed at lower HNO3 concentration (28 wt- %). Similar results are obtained after outdoor tests. Again, the damage occurs only after combined exposure, in contrast to the exposures to UV only and to HNO3 only, which were conducted in parallel. Outdoor exposures are most readily accepted as they represent possible end-use conditions. However, the reproducibility of these exposures is poor due to the large temporal variations in weather. There are also several safety risks, which is why the number of replicates remains limited. Since the outdoor and lab exposure tests show the same qualitative results, it is appropriate to conduct systematic studies in the laboratory. After 6 days of lab exposure, the oxidation damage is rated as critical, which corresponds to about 1/10 year in Central Europe, according to the UV radiant exposure. It should be noted that this amount can also occur in two sunny weeks. T2 - 24th iapri World Packaging Conference CY - Valencia, Spain DA - 17.06.2024 KW - Ppolyethylene KW - UV exposure KW - Nitric acid KW - Oxidation PY - 2024 VL - 2 SP - 30 EP - 37 PB - ITENE AN - OPUS4-60414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Meyer, A. A1 - Falkenhagen, Jana A1 - Kricheldorf, H. R. T1 - SnOct2-catalyzed and alcohol-initiated ROPs of L-lactide – About the influence of initiators on chemical reactions in the melt and the solid state N2 - SnOct2 (Sn(II) 2-ethylhexanoate) catalyzed ROPs of L-lactide were performed in bulk with eight different alcohols as initiators. The time was varied between 1 h and 24 h for all initiators. For two initiators the temperature was also lowered to 115 ◦C. Even-numbered chains were predominantly formed in all polymerizations at short times, but the rate of transesterification (e.g. even/odd equilibration) and the molecular weight distribution were found to depend significantly on the nature of the initiator. Observed transesterification reactions also continued in solid poly (L-lactide), and with the most active initiator, almost total equilibration was achieved even at 130 ◦C. This means that all chains including those of the crystallites were involved in transesterification reactions proceeding across the flat surfaces of the crystallites. The more or less equilibrated crystalline polylactides were characterized by DSC and SAXS measurements with regard to their melting temperature (Tm), crystallinity and crystal thickness. KW - Polylactide KW - MALDI-TOF MS KW - Crystallization KW - Catalysts KW - SAXS PY - 2021 DO - https://doi.org/10.1016/j.eurpolymj.2021.110508 VL - 153 SP - 110508 PB - Elsevier Ltd. AN - OPUS4-52633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Panne, Ulrich A1 - Falkenhagen, Jana T1 - Power of ultra performance liquid chromatography/electrospray ionization-MS reconstructed ion chromatograms in the characterization of small differences in polymer microstructure N2 - From simple homopolymers to functionalized, 3-dimensional structured copolymers, the complexity of polymeric materials has become more and more sophisticated. With new applications for instance in the semiconductor or pharmaceutical industry, the requirements for the characterization have risen with the complexity of the used polymers. For each additional distribution, an additional dimension in analysis is needed. Small, often isomeric heterogeneities in topology or microstructure can usually not be simply separated chromatographically or distinguished by any common detector, but affect the properties of materials significantly. For a drug delivery system for example, the degree of branching and branching distribution is crucial for the formation of micelles. Instead of a complicated, time consuming and/or expensive 2d-chromatography or ion mobility spectrometry (IMS) method, that also has its limitations, in this work a simple approach using size exclusion chromatography (SEC) coupled with electrospray ionization mass spectrometry (ESI) is proposed. The online coupling allows the analysis of reconstructed ion chromatograms (RIC) of each degree of polymerization. While a complete separation often cannot be achieved, the derived retention times and peak widths lead to information on the existence and dispersity of heterogeneities. Although some microstructural heterogeneities like short chain branching can for large polymers be characterized with methods such as light scattering, for oligomers where the heterogeneities just start to form and their influence is at the maximum, they are inaccessible with these methods. It is also shown, that with a proper calibration even quantitative information can be obtained. This method is suitable to detect small differences in e. g. branching, 3d-structure, monomer sequence or tacticity and could potentially be used in routine analysis to quickly determine deviations. KW - Polymer KW - Microstructure KW - UPLC KW - ESI-TOF-MS KW - Reconstructed ion chromatograms PY - 2018 DO - https://doi.org/10.1021/acs.analchem.7b05214 SN - 0003-2700 SN - 1520-6882 VL - 90 IS - 5 SP - 3467 EP - 3474 PB - ACS Publ. CY - Washington, DC AN - OPUS4-44423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Characterization of co (polyamide)s N2 - Charactrization of Co(polyamide)s Molar mass distribution; Functionalization; supression of end group effects in favor of sequence distribution analysis; Evidence of of randomization with increasing reaction time T2 - Polyamide Meeting, DSM CY - Sittard, The Netherlands DA - 20.04.2018 KW - Liquid chromatography KW - Mass spectrometry of polymers PY - 2018 AN - OPUS4-44747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epping, Ruben A1 - Falkenhagen, Jana T1 - Characterization of small heterogeneities in polymers by analysis of UPLC/ESI-MS reconstructed ion chromatograms N2 - From simple molar mass disperse homopolymers over copolymers to functionalized, 3-dimensional structures containing various distributions, the complexity of polymeric materials has become more and more sophisticated in recent years. With applications in medicine, pharmacy, smart materials or for the semiconductor industry the requirements for the characterization have risen with the complexity of the used polymers. For each additional distribution, an additional dimension in analysis is needed. Small, often isobaric heterogeneities in topology or microstructure can usually not be simply separated chromatographically or distinguished by any common detector. Instead of a complicated, time consuming and/or expensive 2d-chromatography or ion mobility spectrometry (IMS) method, that also has its limitations, here a simple approach using size exclusion chromatography (SEC) coupled with electrospray ionization mass spectrometry (ESI) is proposed. We used SEC for the separation because unlike other separation modes the separation in this mode solely should occur due to the hydrodynamic volume with no interference of other interactions. This simplifies the interpretation and the above mentioned heterogeneities should show a slight difference in hydrodynamic volume. ESI mass spectrometry can offer more than an access to mass dependent information like MMD, end group masses or CCD in polymer analysis. The online coupling to SEC allows the analysis of reconstructed ion chromatograms (RIC) of each degree of polymerization. While a complete separation often cannot be achieved, the derived retention times and peak widths lead to information on the existence and dispersity of heterogeneities in microstructure or topology, that are otherwise inaccessible or accessible only by time consuming or expensive methods. Because these heterogeneities might vary with the molar mass, analysis of the whole MMD-Peak (here the total ion current (TIC)) would not lead to the desired information. The broadening of the chromatographic peaks in this case does not origin from the already well known band broadening factors in chromatography from diffusion. This band broadening is attributed to the nature and composition of the analyte itself. Surprisingly there is very little investigation into the peak width or peak shape due to analyte structure itself found in literature. It is also shown, that with proper calibration even quantitative information could be obtained. This method is suitable to detect small differences in e. g. branching, topology, monomer sequence or tacticity and could potentially be used in production control of oligomeric products or other routinely done analyses to quickly indicate deviations from set parameters. Based on a variety of examples we demonstrate the possibilities and limitations of this approach. T2 - HTC-15 CY - Cardiff, UK DA - 24.01.2018 KW - UPLC/ESI-MS KW - Reconstructed chromatograms KW - Polymer analysis KW - Microstructure PY - 2018 AN - OPUS4-44137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Pöthkow, K. A1 - Paetsch, O. A1 - Hege, H.-C. T1 - 3D reconstruction and quantification of dislocation substructures from TEM stereo pairs N2 - Dislocations are the carriers of plastic deformation. As such, their characterization offers important information on the properties they affect. In this contribution, a new tool is presented, which is incorporated in Amira ZIB Edition and allows for three-dimensional (3D) imaging and quantification of dislocations substructures from thick regions an electron-transparent specimen. In the tool, the dislocation segments are traced on diffraction contrast images that are obtained in the transmission electron microscope (TEM). The uncertainties related to the experimental setup and to the proposed method are discussed on the base of a tilt series. T2 - AVIZO / AMIRA User Meeting CY - Berlin, Germany DA - 14.11.2018 KW - Dislocation KW - Diffraction contrast KW - Scanning transmission electron microscopy (STEM) PY - 2018 AN - OPUS4-47394 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Agudo Jácome, Leonardo A1 - Pöthkow, K. A1 - Paetsch, O. A1 - Hege, H.-C. T1 - Three-dimensional reconstruction and quantification of dislocation substructures from transmission electron microscopy stereo pairs N2 - A great amount of material properties is strongly influenced by dislocations, the carriers of plastic deformation. It is therefore paramount to have appropriate tools to quantify dislocation substructures with regard to their features, e.g., dislocation density, Burgers vectors or line direction. While the transmission electron microscope (TEM) has been the most widely-used equipment implemented to investigate dislocations, it usually is limited to the two-dimensional (2D) observation of three-dimensional (3D) structures. We reconstruct, visualize and quantify 3D dislocation substructure models from only two TEM images (stereo pairs) and assess the results. The reconstruction is based on the manual interactive tracing of filiform objects on both images of the stereo pair. The reconstruction and quantification method are demonstrated on dark field (DF) scanning (S)TEM micrographs of dislocation substructures imaged under diffraction contrast conditions. For this purpose, thick regions (> 300 nm) of TEM foils are analyzed, which are extracted from a Ni-base superalloy single crystal after high temperature creep deformation. It is shown how the method allows 3D quantification from stereo pairs in a wide range of tilt conditions, achieving line length and orientation uncertainties of 3% and 7°, respectively. Parameters that affect the quality of such reconstructions are discussed. KW - Dislocation KW - Diffraction contrast KW - Scanning transmission electron microscopy (STEM) KW - Stereoscopy KW - Visualization PY - 2018 DO - https://doi.org/10.1016/j.ultramic.2018.08.015 SN - 0304-3991 VL - 195 SP - 157 EP - 170 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-46355 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baumann, Maria A1 - Falkenhagen, Jana A1 - Weidner, Steffen A1 - Wold, C. A1 - Uliyanchenko, E. T1 - Characterization of copolymers of polycarbonate and polydimethylsiloxane by 2D chromatographic separation, MALDI-TOF mass spectrometry, and FTIR spectroscopy N2 - The structure and composition of polycarbonate polydimethylsiloxane copolymer (PC-co-PDMS) was investigated by applying various analytical approaches including chromatographic separation methods, spectrometric, and spectroscopic detection techniques. In particular, size exclusion chromatography (SEC) and liquid adsorption chromatography operating at different conditions (e.g. using gradient solvent systems) were used to achieve separations according to molar mass and functionality distribution. The coupling of both techniques resulted in fingerprint two-dimensional plots, which could be used to easily compare different copolymer batches. Matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry was applied for structural investigations. The different ionization behavior of both comonomers, however, strongly limited the applicability of this technique. In contrast to that, Fourier-transform Infrared (FTIR) spectroscopy could be used to quantify the amount of PDMS in the copolymer at different points in the chromatogram. The resulting methodology was capable of distinguishing PC-co-PDMS copolymer from PC homopolymer chains present in the material. KW - FTIR KW - Liquid chromatography KW - Mass spectrometry KW - Gradient elution KW - Polycarbonate-co-dimethylsiloxane copolymer PY - 2020 DO - https://doi.org/10.1080/1023666X.2020.1820170 VL - 25 IS - 7 SP - 1 EP - 12 PB - Taylor & Francis AN - OPUS4-51369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Weidner, Steffen A1 - Epping, Ruben T1 - Coupling of chromatographic and spectrometric techniques for polymer characterization N2 - Coupling of chromatographic and spectrometric techniques for polymer characterization; focus topics: LCxMALDI-TOF-MS and UPLC x ESI-TOF-MS T2 - 16. Tagung des Arbeitskreises Polymeranalytik CY - Online meeting DA - 22.03.2022 KW - Liquid chromatography KW - Mass spectrometry KW - Polymers KW - Two-dimensional chromatography (2D-LC) PY - 2022 AN - OPUS4-54567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander A1 - Hoffmann, V. A1 - Morcillo, Dalia A1 - Agudo Jácome, Leonardo A1 - Leonhardt, Robert A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique T1 - Investigation of degradation of the aluminum current collector in lithium-ion batteries by glow-discharge optical emission spectroscopy N2 - Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs.[1] Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs. T2 - European Winter Conference on Plasma Spectrochemistry (EWCPS 2023) CY - Ljubljana, Slovenia DA - 29.01.2023 KW - Lithium-ion batteries KW - Aging mechanisms KW - Depth-profiling PY - 2023 AN - OPUS4-56992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn A1 - Eddah, Mustapha A1 - Bajer, Evgenia A1 - Markötter, Henning A1 - Kranzmann, Axel T1 - Destructive and non-destructive 3D-characterization of inner metal structures in ceramic packages N2 - Ceramic multilayer packages provide successful solutions for manifold applications in telecommunication, microsystem, and sensor technology. In such packages, three-dimensional circuitry is generated by combination of structured and metallized ceramic layers by means of tape casting and multilayer technology. During development and for quality assurance in manufacturing, characterization of integrity, deformation, and positioning of the inner metal features is necessary. Visualization with high resolution and material contrast is needed. Robot-assisted 3D-materialography is a useful technique to characterize such multimaterial structures. In that, many sections of the specimen are polished and imaged automatically. A three-dimensional representation of the structure is created by digital combination of the image stack. A quasi non-destructive approach is to perform X-ray computer tomography (CT) with different beam energies. The energies are chosen to achieve a good imaging of either the metal features, or the ceramic matrix of the structure. The combination of the respective tomograms results in a high contrast representation of the entire structure. Both methods were tested to characterize Ag and Ag/Pd conductors in a ceramic multilayer package. The results were compared in terms of information content, effort, and applicability of the methods. T2 - 98th DKG Annual Meeting - CERAMICS 2023 CY - Jena, Germany DA - 27.03.2023 KW - Ceramics KW - Synchrotron CT KW - 3D materialography PY - 2023 AN - OPUS4-57268 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kianinejad, kaveh A1 - Fedelich, Bernard A1 - Darvishi Kamachali, Reza A1 - Schriever, Sina A1 - Manzoni, Anna Maria A1 - Agudo Jácome, Leonardo A1 - Megahed, Sandra A1 - Kamrani, Sepideh A1 - Saliwan-Neumann, Romeo T1 - Experimentally informed multiscale creep modelling of additive manufactured Ni-based superalloys N2 - Excellent creep resistance at elevated temperatures, i.e. T / T_m> 0.5, due to γ-γ’ microstructure is one of the main properties of nickel-based superalloys. Due to its great importance for industrial applications, a remarkable amount of research has been devoted to understanding the underlying deformation mechanism in a wide spectrum of temperature and loading conditions. Additive manufactured (AM) nickel-based superalloys while being governed by similar γ-γ’ microstructure, exhibit AM-process specific microstructural characteristics, such as columnar grains, strong crystallographic texture (typically <001> fiber texture parallel to build direction) and compositional inhomogeneity, which in turn leads to anisotropic creep response in both stationary and tertiary phases. Despite the deep insights achieved recently on the correlation between process parameters and the resulting microstructure, the anisotropic creep behavior and corresponding deformation mechanism of these materials are insufficiently understood so far. One reason for this is the lack of capable material models that can link the microstructure to the mechanical behavior. To overcome this challenge, a multiscale microstructure-based approach has been applied by coupling crystal plasticity (CP) and polycrystal model which enables the inclusion of different deformation mechanisms and microstructural characteristics such as crystallographic texture and grain morphology. The method has been applied to experimental data for AM-manufactured INCONEL-738LC (IN738). The effect of different slip systems, texture, and morphology on creep anisotropy at 850°C has been investigated. Results suggest a strong correlation between superlattice extrinsic stacking fault (SESF) and microtwinning and observed creep anisotropy. T2 - EUROMAT 23 CY - Frankfurt a. M., Germany DA - 04.09.2023 KW - IN738LC KW - Creep anisotropy KW - Crystal plasticity PY - 2023 AN - OPUS4-58263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dudziak, Mateusz A1 - Topolniak, Ievgeniia A1 - Silbernagl, Dorothee A1 - Altmann, Korinna A1 - Sturm, Heinz T1 - Long-time behavior of surface properties of microstructures fabricated by multiphoton lithography N2 - The multiphoton lithography (MPL) technique represents the future of 3D microprinting, enabling the production of complex microscale objects with high precision. Although the MPL fabrication parameters are widely evaluated and discussed, not much attention has been given to the microscopic properties of 3D objects with respect to their surface properties and time-dependent stability. These properties are of crucial importance when it comes to the safe and durable use of these structures in biomedical applications. In this work, we investigate the surface properties of the MPL-produced SZ2080 polymeric microstructures with regard to the physical aging processes during the post-production stage. The influence of aging on the polymeric microstructures was investigated by means of Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). As a result, a time-dependent change in Young’s Modulus, plastic deformation, and adhesion and their correlation to the development in chemical composition of the surface of MPL-microstructures are evaluated. The results presented here are valuable for the application of MPL-fabricated 3D objects in general, but especially in medical technology as they give detailed information of the physical and chemical time-dependent dynamic behavior of MPL-printed surfaces and thus their suitability and performance in biological systems. KW - Multiphoton lithography KW - Additive manufacturing KW - Microfabrication KW - SZ2080 negative photo-resist KW - Young´s modulus KW - Aging KW - Surface properties KW - X-ray photoelectron spectroscopy KW - Atomic force microscopy KW - Force-distance-curve PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542166 DO - https://doi.org/10.3390/nano11123285 SN - 2079-4991 VL - 11 IS - 12 SP - 1 EP - 12 PB - MDPI CY - Basel AN - OPUS4-54216 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Raschpichler, C. A1 - Goroncy, C. A1 - Langer, B. A1 - Antonsson, E. A1 - Wassermann, B. A1 - Graf, C. A1 - Klack, Patrick A1 - Lischke, T. A1 - Rühl, E. T1 - Surface Properties and Porosity of Silica Particles Studied by Wide-Angle Soft X-ray Scattering N2 - Wide-angle soft X-ray scattering on free silica particles of different porosity prepared in a beam is reported. The explored q region is mostly dominated by features due to surface roughness and bulk porosity. A comprehensive experimental and theoretical analysis of silica particles of different porosity is presented for various incident photon energies. A correlation analysis, based on the theory of Porod, is used to test the validity of exact Mie theory in different pore density limits. The ability of the discrete dipole scattering model (DDSCAT) to resolve local effects, caused by various pore distributions, is discussed. Characteristic differences between the soft X-ray scattering patterns of the particle samples of different surface properties and porosity are detected. For all mentioned cases, it was confirmed that the effective radius concept of the Guinier model can be successfully extended to Mie theory and DDSCAT in describing the additive contributions of the primary particles, including a thin inhomogeneous solvent-rich surface shell and empty bulk pores. Close agreement, within ±15%, between the calculated and observed pore sizes and porosity values is reached. The influence of pores is alternatively described either in terms of secondary Mie scattering, which is modulated by the local internal electrical field within the particles, or by an independent Mie scattering process induced by the incident field on isolated pores. It is found that for the typical pore/particle size ratios the latter approach presents the best choice. KW - Wide-Angle Soft X‑ray Scattering KW - Silica KW - Porosity PY - 2020 DO - https://doi.org/10.1021/acs.jpcc.0c04308 SN - 1932-7447 SN - 1932-7455 VL - 124 SP - 16663 EP - 16674 AN - OPUS4-51089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Meyer, A. A1 - Falkenhagen, Jana A1 - Kricheldorf, H. R. T1 - Polycondensations and Cyclization of Poly(L-lactide) Ethyl Esters in the Solid State N2 - The usefulness of seven different Tin catalysts, Bismuth subsalicylate and Titan tetra(ethoxide) for the polycondensation of ethyl L-lactate (ELA) was examined at 150 °C/6 d. Dibutyltin bis(phenoxides) proved to be particularly effective. Despite the low reactivity of ELA, weight average molecular masses (Mw) up to 12 500 were found along with partial crystallization. Furthermore, polylactides (PLAs) of similar molecular masses were prepared via ELA-initiated ROPs of L-lactide by means of the four most effective polycondensation catalysts. The crystalline linear PLAs were annealed at 140 or 160 °C in the presence of these catalysts. The consequences of the transesterification reactions in the solid PLAs were studied by means of matrix-assisted laser desorption/ionization (MALDI TOF) mass spectrometry, gel permeation chromatography (GPC) and small-angle X-ray scattering (SAXS). The results indicate that polycondensation and formation of cycles proceed in the solid state via formation of loops on the surface of the crystallites. In summary, five different transesterification reactions are required to explain all results. KW - Polylactide KW - MALDI-TOF MS KW - Crystalinity PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-592934 DO - https://doi.org/10.1039/d3py01232h SN - 1759-9962 VL - 15 IS - 2 SP - 71 EP - 82 PB - RSC Publ. CY - Cambridge AN - OPUS4-59293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Epping, Ruben T1 - View into the depths of copolymer microstructure by a special approach of LC-MS data evaluation N2 - It is a well-known story that copolymers beside their molar mass distribution (MMD) can exhibit a functionality type distribution (FTD), a copolymer composition distribution (CCD), a monomer sequence distribution (MSD) and additionally different topologies within one sample. This is and will remain a challenge for analysts. First a very short overview will be given concerning the common liquid separation techniques for polymers (SEC, LAC, LCCC, GELC) coupled to soft ionization mass spectrometric methods like MALDI and ESI-MS with focus on their limitations. For very broadly distributed samples or chemical very similar species the superposition of different separation mechanisms in chromatography is unavoidable or the separation efficiency cannot be optimized. Different ionization probabilities and species of the same nominal mass with completely different structures are just two problems of mass spec of complex polymer mixtures. Subsequently, different examples will be shown how these limitations in some cases could be outsmarted. First example will be the separation of statistical EO-PO copolymers of different chemical compositions by end group functionality and the quantification of end group fractions over the whole CCD. Here an UP-LCCC / ESI-TOF-MS coupling is applied. Further for different kinds of polymers it will be shown how it could be realized to obtain information on small isobaric/isomeric topological heterogeneities by coupling UP-SEC / ESI-TOF-MS. All results are based on the data processing of reconstructed ion chromatograms of single mass traces of complex ESI-MS spectra. T2 - SCM-9 CY - Amsterdam, The Netherlands DA - 29.01.2019 KW - Reconstructed ion chromatograms KW - Copolymer KW - Microstructure KW - LC x ESI-TOF-MS PY - 2019 AN - OPUS4-47836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander A1 - Hoffmann, V. A1 - Morcillo, Dalia A1 - Agudo Jácome, Leonardo A1 - Leonhardt, Robert A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique A1 - You, Zengchao T1 - Investigation of degradation of the aluminum current collector in lithium-ion batteries by glow-discharge optical emission spectroscopy N2 - Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs. Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs. T2 - Adlershofer Forschungsforum 2022 CY - Berlin, Germany DA - 11.11.2022 KW - Lithium Ion Batteries KW - GD-OES KW - FIB KW - SEM KW - EDX PY - 2022 AN - OPUS4-56246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Shedding Light into Polymer Microstructure N2 - It is a well-known story that copolymers beside their molar mass distribution (MMD) can exhibit a functionality type distribution (FTD), a copolymer composition distribution (CCD), a monomer sequence distribution (MSD) and additionally different topologies within one sample. Nowadays a wide range of different analytical separation techniques and multi-detection possibilities are available. The challenge consists in a clever combination of these techniques coordinated with the heterogeneity to be investigated. A number of applications will be presented from e.g. topology elucidation of branched EO-PO “academic” copolymers to copolymer composition of partially broadly distributed progressively tailored “industrial relevant” copolymers consisting of e.g. polyamides, polycarbonates and polysiloxanes. Multidimensional separation techniques will be demonstrated with focus on mass spectrometric detection techniques (ESI-/MALDI-TOF-MS) coupled online or semi-online to prior separation. T2 - FAST 2019, COAST Community of Innovation CY - Veldhoven, The Netherlands DA - 21.05.2019 KW - LCCC KW - Mass spectrometry of polymers KW - SEC KW - LC x MALDI/ESI-TOF-MS coupling PY - 2019 AN - OPUS4-48222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Coupling of chromatographic and spectrometric techniques for polymer characterization N2 - Presentation of coupling of polymer chromatography and polymer mass spectrometry based on different examples. T2 - Kolloquium CY - Universität für Bodenkultur, Wien, Austria DA - 14.06.2019 KW - LCCC KW - Mass spectrometry of polymers KW - LC x MALDI/ESI-TOF-MS KW - Liquid chromatography of polymers PY - 2019 AN - OPUS4-48223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chapartegui-Arias, Ander A1 - Villajos Collado, José Antonio A1 - Myxa, Anett A1 - Beyer, Sebastian A1 - Falkenhagen, Jana A1 - Schneider, Rudolf A1 - Emmerling, Franziska T1 - Covalently Fluorophore-Functionalized ZIF‑8 Colloidal Particles as a Sensing Platform for Endocrine-Disrupting Chemicals Such as Phthalates Plasticizers N2 - We present the optical sensing of phthalate Esters (PAEs), a group of endocrine-disrupting chemicals. The sensing takes place as changes in the fluorescence emission intensity of aminopyrene covalently bound to the organic ligands of the metal−organic framework compound ZIF-8. In the presence of PAEs, a quenching of the fluorescence emission is observed. We evaluated strategies to engineer colloidal size distribution of the sensing particles to optimize the sensory response to PAEs. A thorough characterization of the modified ZIF-8 nanoparticles included powder X-ray diffractometry, transmission electron microscopy, high-performance liquid chromatography, and photophysical characterization. The presented capability of the fluorophore-functionalized ZIF-8 to sense PAEs complements established methods such as chromatography-based procedures, which cannot be used on-site and paves the way for future developments such as hand-held quick sensing devices. KW - Sensing KW - MOF PY - 2019 DO - https://doi.org/10.1021/acsomega.9b01051 VL - 4 IS - 17 SP - 17090 EP - 17097 PB - ACS AN - OPUS4-49562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Epping, Ruben T1 - View into the Depths of Copolymer Microstructure N2 - For different kinds of polymers it will be shown how it could be realized to obtain information on small, sometimes isomeric topological heterogeneities by coupling UPLC / ESI-TOF-MS and LC /MALDI-TOF-MS. T2 - DSM, Fall Meeting CY - Breda, The Netherlands DA - 07.11.2019 KW - Microstructure KW - LC-MS KW - Copolymer PY - 2019 AN - OPUS4-49587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen A1 - Falkenhagen, Jana A1 - Kricheldorf, H. T1 - Polymer mass spectrometry at BAM with special emphasis on MALDI and ESI N2 - Since its introduction mass spectrometric techniques like Matrix-assisted Laser Desorption/ionization (MALDI) and Electrospray Ionization (ESI) have become indispensable for synthetic polymer analyses. Ideally, various polymer properties (monomer structure, masses, mass distribution, end groups) can be determined simultaneously. However, in real life these experiments are always affected by important structural parameters and instrumental limitations. A short introduction focussing on latest findings with respect to ionisation principles and mechanisms will be given. Recent results from our group will be presented and efforts to avoid common drawbacks of polymer mass spectrometry will be discussed. In this regard, MALDI - Imaging mass spectrometry and the 2D hyphenation of MS with different chromatographic separation techniques were especially useful, since they can provide additional information and reduce the complexity of polymer analyses. T2 - 21. European Symposium on Polymer Spectroscopy CY - Linz, Austria DA - 13.01.2020 KW - Mass spectrometry KW - MALDI-TOF MS KW - ESI-TOF MS KW - Polymer PY - 2020 AN - OPUS4-50260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen A1 - Rienitz, O. A1 - Rosner, M. A1 - Mieller, Björn A1 - Kasemann, S. A1 - Kraft, R. A1 - Malinovskiy, D. A1 - Meixner, A. A1 - Noordmann, J. A1 - Rabb, S. A1 - Schuessler, J. A. A1 - Vocke, R. D. T1 - Calibration of Mg isotope amount ratios and delta values N2 - In the past, δ26/24Mg measurements were referenced to NIST SRM 980, the initial zero of the δ26/24Mg scale. With the development of MC-ICPMS, the detection of small but measurable isotopic differences in different chips of SRM 980 became apparent. To solve this problem a suite of magnesium isotope reference materials, ERM-AE143, -AE144 and -AE145, has been certified in a first study by applying an ab initio calibration for absolute Mg isotope ratios without any a priori assumptions, a procedure which fulfils all requirements of a primary method of measurement. We could achieve for the first time measurement uncertainties for isotope amount ratios close to the typical precision of magnesium delta values, δ26/24Mg, which are at the 0.1 ‰ level (2SD). In addition, it was demonstrated that commonly used fractionation laws are invalid for correcting Mg isotope ratios in multi-collector ICPMS as they result in a bias which is not covered by its associated uncertainty. Depending on their type, fractionation laws create a bias up to several per mil, with the exponential law showing the smallest bias between 0.1 ‰ to 0.7 ‰. With these isotope reference materials, it is possible to establish SI-traceability for magnesium delta measurements. To realize this, we organized a second study within which five expert laboratories participated to cross-calibrate all available magnesium isotope standards, which are NIST SRM 980, IRMM-009, ERM-AE143, ERM-AE144, ERM-AE145 and the standards DSM3 and Cambridge-1. The mean δ26/24Mg values for the individual iRMs, calculated from the laboratory means show 2 SD reproducibilities varying between 0.025 and 0.093 ‰. Propagated measurement uncertainties suggest a standard uncertainty of about 0.1‰ for δ26/24Mg determinations (2SD). Thus, SI traceability for magnesium isotope amount ratios and delta values is demonstrated to be established. T2 - 53rd annual conference of the DGMS including 27th ICP-MS User's Meeting CY - Münster, Germany DA - 01.03.2020 KW - Isotope ratio KW - Delta value KW - Metrology KW - Magnesium KW - Magnesium isotope ratios PY - 2020 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. AN - OPUS4-50549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Epping, Ruben T1 - Microstructure characterization of oligomers by analysis of UPLC / ESI-TOF-MS reconstructed ion chromatograms N2 - It is a well-known story that copolymers beside their molar mass distribution (MMD) can exhibit a functionality type distribution (FTD), a copolymer composition distribution (CCD), a monomer sequence distribution (MSD) and additionally different topologies within one sample. Small, often isobaric heterogeneities in topology or microstructure can usually not be simply separated chromatographically or distinguished by any common detector. Nowadays a wide range of different analytical separation techniques and multi-detection possibilities are available. The challenge consists in a clever combination of these techniques with a specific approach of data analysis. In this presentation different liquid chromatographic separation modes were combined with Electrospray Time-of-Flight mass spectrometry. The online coupling allows the analysis of reconstructed ion chromatograms (RIC) of each degree of polymerization. While a complete separation often cannot be achieved, the derived retention times and peak widths lead to information on the existence and dispersity of heterogeneities in microstructure or topology, that are otherwise inaccessible This method is suitable to detect small differences in e. g. branching, topology, monomer sequence or tacticity and could potentially be used in production control of oligomeric products or other routinely done analyses to quickly indicate deviations from set parameters. Based on a variety of examples e.g. the topology elucidation of branched EO-PO copolymers, the possibilities and limitations of this approach were demonstrated. T2 - Analyticon 2020 CY - Online meeting DA - 05.11.2020 KW - Microstructure KW - Copolymer KW - LC-MS PY - 2020 AN - OPUS4-51540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander A1 - Hoffmann, V. A1 - Morcillo, Dalia A1 - Agudo Jácome, Leonardo A1 - Leonhardt, Robert A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique A1 - You, Zengchao T1 - Chemical characterization of aging processes in high energy-density lithium-ion batteries N2 - Introduction Lithium-ion batteries (LIBs) are one key technology to overcome the climate crisis and energy transition challenges. Demands of electric vehicles on higher capacity and power drives research on innovative cathode and anode materials. These high energy-density LIBs are operated at higher voltages, leading to increased electrolyte decay and the current collectors' degradation. Even though this fundamental corrosion process significantly affects battery performance, insufficient research is being done on the aluminum current collector. Fast and convenient analytical methods are needed for monitoring the aging processes in LIBs. Methods In this work glow-discharge optical emission spectrometry (GD-OES) was used for depth profile analysis of aged cathode material. The measurements were performed in pulsed radio frequency mode. Under soft and controlled plasma conditions, high-resolution local determination (in depth) of the elemental composition is possible. Scanning electron microscopy (SEM) combined with a focused ion beam (FIB) cutting and energy dispersive X-ray spectroscopy (EDX) was used to confirm GD-OES results and obtain additional information on elemental distribution. Results The aging of coin cells manufactured with different cathode materials (LCO, LMO, NMC111, NMC424, NMC532, NMC622, and NMC811) was studied. GD-OES depth profiling of new and aged cathode materials was performed. Quantitative analysis was possible through calibration with synthetic standards and correction by sputter rate. Different amounts of aluminum deposit on the cathode surface were found for different materials. The deposit has its origin in the corrosion of the aluminum current collector. The results are compatible with results from FIB-EDX. However, GD-OES is a faster and less laborious analytical method. Therefore, it will accelerate research on corrosion processes in high energy-density batteries. Innovative aspects - Quantitative depth profiling of cathode material -Monitoring of corrosion processes in high energy-density lithium-ion batteries - Systematic investigation of the influence of different cathode materials T2 - ANAKON 2023 CY - Vienna, Austria DA - 11.04.2023 KW - Lithium Ion Batteries KW - GD-OES KW - Depth-profiling PY - 2023 AN - OPUS4-58586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Aghaei, Siavash A1 - Askar, Enis A1 - Krietsch, Arne A1 - Salzano, Ernesto T1 - The Hazard of Soy Flour, n‑Hexane, and Their Hybrid Mixtures in the Extraction Process N2 - Soybean oil takes around half of the vegetable oil resources in the world, increasing in importance constantly. Besides, soy oil plants have experienced numerous accidents due to the coexistence of soy flour and hexane (as a solvent) in the extraction process, thus creating a hazardous environment. This study aims to find the maximum pressure, the maximum rate of pressure rise, and the minimum ignition energy of soy flour−hexane mixtures through specific experiments by varying the concentration of fuels in air and ignition mechanism (chemical igniters or exploding wires). The results have shown that soy flour alone is hard to ignite, whereas adding hexane even in small amounts increases the hazard and the severity of the explosions considerably. Eventually, the substitution of hexane with a greener and safer extraction agent should be of utmost focus. KW - Hybrid Explosions KW - Safety characteristics KW - Hexane KW - Soy Flour PY - 2024 DO - https://doi.org/10.1021/acs.iecr.4c01498 SN - 0888-5885 SP - 1 EP - 9 PB - ACS American Chemical Society AN - OPUS4-60597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -