TY - JOUR A1 - Meyer, Andreas A1 - Weidner, Steffen A1 - Kricheldorf, Hans R. T1 - Star-shaped poly(l-lactide)s based on pentaerythritol: About crystallization and polycondensation plus disproportionation and ring formation in the solid state N2 - Star-shaped poly( L-lactide)s (s-PLAs), were prepared by ring-opening polymerization of with pentaerythritol and catalyzed by tin(II) 2-ethylhyexanoate (SnOct out in bulk at either 120 ◦ C or 160 ◦ L-lactide (LA) initiated 2 ). Two small series of ROPs were carried C with variation of the LA/initiator ratio. Matrix-assisted laser desorption/ ionization time-of-flight (MALDI-TOF) mass spectra revealed traces of cycles in 120 ◦ C samples only at low initiator/catalyst ratios. In contrast, higher fractions of cycles were detected in samples prepared at 160 C, suggesting a "back-biting" origin. The influence of arm length and thermal history on crystallinity was investigated by differential scanning calorimetry (DSC) and wide-angle x-ray scattering (WAXS). It was shown that annealing increased the melting temperature (T ◦ ◦ m ) and crystallinity. However, annealing at 140 ◦ C for 14 d also caused significant solid-state transesterification. In addition, crystallites composed of s-PLAs with extended arms and, simultaneously, crystallites composed exclusively of extended rings were formed, identified by their typical "sawtooth" pattern in the MALDI mass spectra. Small angle x-ray scattering (SAXS) indicated that the crystal thickness was lower than that of linear PLAs annealed under identical conditions, but increased upon annealing at 140 C. KW - MALDI-TOF MS KW - Polylactide KW - Crystallisation KW - AStar-shaped polymers PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636832 DO - https://doi.org/10.1016/j.polymer.2025.128709 SN - 0032-3861 VL - 334 SP - 1 EP - 11 PB - Elsevier Ltd. AN - OPUS4-63683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen T1 - H2O-Initiated Polymerization of L-Lactide N2 - Water-initiated ring-opening polymerizations (ROPs) of L-lactide (LA) were performed in bulk at 140 °C, whereupon 11 different salts or complexes of low-toxic metal ions such as tin (II), Zn(II), Zr(IV), and Bi(III) were used as catalysts. Only four catalysts gave satisfactory results despite a long reaction time (24 h). The influence of the temperature was studied with tin (II) 2-ethylhexanoate (SnOct2), dibutyltin oxide (Bu2SnO), and zinc bis-acetylacetonate (Zn(acac)2) and zirconium acetylacetonate (Zr(acac)4). With SnOct2, Bu2SnO and Zr(acac)4 the time was varied at 140 °C to compare their reactivity. Furthermore, two series of ROPs were carried out with variation of the LA/H2O ratio to verify the control of the molecular weight by the monomer-initiator ratio. Bi- or tri-modal molecular weight distributions (MWD) were found for most of the ROPs and bimodal melting endotherms in the differential scanning calorimetry (DSC) heating traces. The thickness and dependence of the 3D packing of the crystallites were monitored by small-angle X-ray scattering (SAXS) measurements. KW - MALDI-TOF MS KW - Polylactide KW - Ring-opening polymerization KW - Crystallization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628761 DO - https://doi.org/10.1007/s10924-025-03565-w SN - 1572-8919 VL - 33 IS - 6 SP - 2843 EP - 2857 PB - Springer Science and Business Media LLC CY - New York, NY AN - OPUS4-62876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Scholz, Philipp A1 - Jung, Christian A1 - Weidner, Steffen T1 - Thermo-Desorption Gas Chromatography-Mass Spectrometry for investigating the thermal degradation of polyurethanes N2 - Thermo-Desorption Gas Chromatography-Mass Spectrometry (TD-GC-MS) was used to investigate the thermal degradation of two different polyurethanes (PU). PU samples were heated at different heating rates and the desorbed products were collected in a cold injection system and thereafter submitted to GC-MS. Prospects and limitations of the detection and quantification of semi-volatile degradation products were investigated. A temperature dependent PU depolymerization was found at temperatures above 200 °C proved by an increasing release of 1,4-butanediol and methylene diphenyl diisocyanate (MDI) representing the main building blocks of both polymers. Their release was monitored quantitatively based on external calibration with authentic compounds. Size Exclusion Chromatography (SEC) of the residues obtained after thermodesorption confirmed the initial competitive degradation mechanism indicating an equilibrium of crosslinking and depolymerization as previously suggested. Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry of SEC fractions of thermally degraded PUs provided additional hints on degradation mechanism. KW - Thermo-desorption KW - Mass spectrometry KW - Polyurethanes KW - Thermal degradation PY - 2023 DO - https://doi.org/10.1039/D3AY00173C SN - 1759-9660 SP - 1 EP - 6 PB - Royal Society for Chemistry AN - OPUS4-57307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Scheliga, Felix A1 - Kricheldorf, Hans R. T1 - Polycondensation, Cyclization and Disproportionation of Solid Poly(L-lactide) Trifluoroethyl Esters and the Simultaneous Formation of Extended Chain Crystals and Extended Ring Crystals N2 - Two poly(L-lactide)s (PLAs) with a degree of polymerization (DP) of 20 or 100 were prepared by trifluoroethanol-initiated ring-opening polymerization (ROP) catalyzed by tin(II) 2-ethyl hexanoate (SnOct2). These PLAs were annealed at 140 ◦C or at 160 ◦C in the presence of SnOct2, and the changes in topology and molecular weight distribution (MWD) were monitored by matrix-assisted laser desorption/ionization time-of flight (MALDI TOF) mass spectrometry and gel permeation chromatography (GPC). For the PLA with a DP 20, the main reaction was polycondensation combined with higher dispersities. In the case of the DP 100, PLA polycondensation was combined with disproportionation and the formation of a new MWD maximum around m/z 3500. In addition, extensive cyclization occurred, and the resulting cyclic PLAs crystallized separately from the linear chains in the form of extended ring crystals. These results also suggest that both extended chain and extended ring crystals posses the same crystal thickness as a result of thermodynamically controlled transesterification in the solid state. KW - Polycondensation KW - MALDI KW - Polylactide KW - Cyclization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-616441 DO - https://doi.org/10.1016/j.polymer.2024.127800 VL - 315 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-61644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen A1 - Scheliga, Felix T1 - Polycondensation of L-lactic acid: a deeper look into solid state polycondensation N2 - L-Lactic acid (LA) was condensed in the presence of SnCl2 or 4-toluenesulfonic acid (TSA) at 140 °C, and chain growth without cyclization was observed. In addition, poly(L-lactic acid)s (PLAs) with a degree of polymerization (DP) of 25, 50 or 100 were prepared by water-initiated ring-opening polymerization (ROP). These PLAs were annealed in the solid state at 140 °C and 160 °C in the presence of tin(II) 2-ethylhexanoate (SnOct2, SnCl2 or TSA). The changes in the molar mass distribution and in the topology were characterized by means of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and size exclusion chromatography (SEC). With increasing time, fewer side reactions caused higher molar masses and increasing fractions of cyclic polylactides (cPLA) were obtained. Their “saw tooth” pattern in the MALDI-TOF mass spectra indicated the formation of extended ring crystallites in the solid state. TSA was the most active catalyst and caused fewer side reactions than SnCl2, which was the least reactive catalyst. Acetylation of the CH-OH end groups hindered polycondensation and prevented the formation of cPLAs. Reaction mechanisms will be discussed. KW - MALDI-TOF MS KW - Polycondensation KW - Polylaktide KW - Solid state PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625271 DO - https://doi.org/10.1039/d4py01191k SN - 1759-9962 SP - 1 EP - 9 PB - Royal Society of Chemistry (RSC) AN - OPUS4-62527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rösler, Alexander A1 - Weidner, Steffen A1 - Klamroth, Tillmann A1 - Müller, Axel HE A1 - Schlaad, Helmut T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. KW - Myrcene KW - Anionic polymerization KW - Reaction order KW - Activation energy KW - Microstructure KW - Quantum chemical calculation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636840 DO - https://doi.org/10.1002/pi.6772 SN - 0959-8103 SP - 1 EP - 8 PB - Wiley AN - OPUS4-63684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen A1 - Meyer, A. T1 - About Polycondensation, Disproportionation, and Cyclization of Acetylated Poly(L-Lactide) Esters N2 - L-lactide (LA) is polymerized with ethyl L-lactate or trifluoroethanol as initiators (LA/In = 30/1), and the resulting poly(L-lactide) esters are acetylated with acetic anhydride. The acetylated PLA esters are mixed with SnOct2, dibutyltin bis(4-chlorophenoxide), or dibutyltin bis(pentafluorophenoxide) in solution and crystallized at 120 °C. The doped crystals are annealed at 140 °C or at 160 °C for 7, 14, and 28 days, and the chemical modifications that occurred in the solid state are monitored by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) measurements. All catalysts promoted polycondensation, while no significant formation of cycles is observed. However, in the presence of SnOct2, disproportionation of chains occurred upon annealing at 120 or 140 °C, and crystallites consisting of extended chains with Mn values ≈3500 – 3600 and low dispersities (Ð < 1.5) are formed. KW - MALDI-TOF MS KW - Polycondensation KW - Polylactides KW - Transesterifcation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630349 DO - https://doi.org/10.1002/macp.202400175 SN - 1521-3935 VL - 225 IS - 19 PB - Wiley VHC-Verlag AN - OPUS4-63034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen T1 - Syntheses of cyclic polylactides and the problem of catenane formation N2 - Cyclic poly(L-lactide)s (PLAs) were prepared in bulk either by ring-expansion polymerization (REP) or by ring-opening polymerization (ROP) with simultaneous polycondensation (ROPPOC). In contrast to REP the latter method involves formation of linear chains and thus, may involve formation of polydisperse catenanes that affect crystallization. The reprecipitated PLAs were annealed at 120 °C and compared with regard to melting temperature (Tm) and melting enthalpy (ΔHm). For similar molar masses the PLAs prepared by REP and ROPPOC had almost identical Tm's and crystallinities. Furthermore, the influence of REP and ROPPOC catalysts on the morphology of the virgin reaction products was compared. KW - MALDI-TOF MS KW - Catenane KW - Polylactide PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625061 DO - https://doi.org/10.1039/d4ra08683j VL - 15 IS - 5 SP - 3686 EP - 3692 PB - RSC AN - OPUS4-62506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Altmann, Korinna T1 - Reference material BAM-P206 polyethylene terephthalate (powder) N2 - This report contains detailed information on the preparation of the reference material as well as on homogeneity and stability investigations of the property of interest, the equivalent particle diameter, and on the analytical methods to determine the additional properties. The values for particle size distribution are based on the results from laser diffraction measurements of 3 different devices with at least 3 replicate measurements of 4 randomly chosen units of the reference material P206. KW - Microplastic KW - Reference material KW - PET PY - 2023 DO - https://doi.org/10.26272/opus4-59778 SP - 1 EP - 23 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-59778 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Kittner, Maria A1 - Altmann, Korinna A1 - Hamann, Sven A1 - Weyer, Rüdiger A1 - Kalbe, Ute T1 - Bewertung der Freisetzung von Mikroplastik aus Sportböden auf Kunststoffbasis - Abschlussbericht N2 - Die Europäische Kommission hat 2023 ein Verbot zum bewussten Austrag von Mikroplastik (MP) in die Umwelt beschlossen, das auch für die Verwendung von synthetischen Gummi-Granulaten (v. a. EPDM) in Sportböden gilt. In Deutschland gibt es laut DFB ca. 5100 Kunstrasenplätze. In der EU beläuft sich die Anzahl laut ECHA auf 13,000 Kunstrasen- und 47,000 Bolzplätze, Tendenz steigend. Das Hauptziel des Projektes war es daher, eine Massenbilanz für die Freisetzung von MP zu erstellen, um so eine Schätzung des MP-Austrags pro Kunstrasenplatz und Jahr zu ermöglichen. Dafür werden die MP-Emissionen von drei Kunstrasenszenarien in verschiedenen Zuständen (ungealtert, künstlich gealtert und in Echtzeit gealtert) verglichen: die Vergangenheit (Kunstrasen: fossilbasiert, EPDM-Füllung), die Gegenwart (der in Europa am häufigsten installierte Rasen) und die Zukunft (Rasen mit recycelten Grasfasern, keine synthetische Füllung sondern z.B. Quarzsand oder Korkschrott). Dazu werden fabrikneue Kunststoffrasen und EPDM-Granulat unter Laborbedingungen beschleunigt gealtert, um die Freiland-Beanspruchung eines Kunststoffrasens in circa 15 Jahren abzubilden. Die Verwendung spezieller Mikrofiltertiegel in Lysimeter-Experimenten ermöglicht die Abschätzung der Partikelgrößen des emittierten MP, was eine Grundbedingung für die Bewertung einer potenziellen Gesundheitsgefährdung für Menschen ist. Ergänzend wurden weitere umweltrelevante Schadstoffausträge aus den Kunststoffrasen quantifiziert. KW - Mikroplastik KW - Kunststoffrasen KW - Schadstoffe KW - Bewitterung KW - Lysimeter PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633114 DO - https://doi.org/10.26272/opus4-63311 N1 - Das Projekt wurde gefördert vom Bundesinstitut für Bau-, Stadt- und Raumforschung (BBSR) im Auftrag des Bundesministeriums für Wohnen, Stadtentwicklung und Bauwesen (BMWSB) aus Mitteln des Innovationsprogramms Zukunft Bau. Aktenzeichen: FKZ 10.08.18.7-22.02. Projektlaufzeit: 09.2022 bis 03.2025. SP - 1 EP - 75 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-63311 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oksal-Kilinc, Sefine A1 - Altmann, Korinna A1 - Seiwert, Bettina A1 - Reemtsma, Thorsten A1 - Ruess, Liliane T1 - Grinding method and oxidative aging modulate the impact of tire wear microplastics on the reproduction of the nematode C. elegans N2 - Rationale Tire abrasion is one of the largest sources of microplastic in aquatic and terrestrial environments. Despite this fact, research on tire wear microplastic (TWP) and its effects on soil ecosystems is scarce, especially regarding natural weathering processes. This leaves a large knowledge gap on the interactions of TWP with soil biota. Methodology Cryo-milled tire tread (CMTT) and diamond-ground tire tread (DGTT) were artificially weathered through dry ozone treatment and heat exposure. Particles were analyzed via scanning electron microscopy, particle size distribution, and shape characterization. TWP leachate composition was examined using liquid chromatography–mass spectrometry. The impact on the reproduction of the nematode Caenorhabditis elegans, a widely used toxicological model, was tested for leachate concentration, exposure duration and TWP aging status, using offspring per adult as the endpoint. Results The comminution method significantly influenced TWP particle size distribution, with diamond grinding yielding smaller particles and a more structured surface morphology than cryo-milling. Aging with ozone (180 min) and heat (20 min at 100 °C) reduced DGTT particle sizes by 27-58%, but not in CMTT. Additionally, aging increased carboxylic functional groups and led to a brittle structure in both TWP types. Leachate composition varied with comminution method and aging. Benzothiazole, N-Cyclo-N-phenylurea, and aniline were more abundant in pristine and aged CMTT and aged DGTT. Diphenylguanidine had the highest concentration in all leachates. Aged TWP leachates, regardless of comminution, had significant toxic effects on C. elegans. Leachate from pristine CMTT was more toxic than from pristine DGTT. Nematode offspring correlated negatively with ozone exposure duration in aged DGTT. Tests with aged CMTT leachate showed even short-term exposure reduced offspring numbers. Discussion The results underscore the importance of oxidative and mechanical weathering in TWP toxicity and challenge the use of pristine particles in toxicological assays for risk assessment in the natural environment. KW - Microplastics KW - Tire abrasion KW - Environment PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654672 DO - https://doi.org/10.1071/EN25051 SN - 1448-2517 VL - 23 IS - 2 SP - 1 EP - 16 PB - CSIRO Publishing AN - OPUS4-65467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiesner, Yosri A1 - Eisentraut, Paul A1 - Altmann, Korinna T1 - One Year Observation of Microplastic Concentrations in the River Rhine N2 - In recent years, the quantification of microplastics (MP) in aquatic environments has gained increasing attention, particularly regarding their environmental distribution and potential exposure levels. Environmentally relevant exposure data are still essential for a realistic risk assessment of the harmful health potential of microplastics in freshwater systems. This study addresses a large data set of MP concentrations analyzed and processed under statistical aspects and provides mass concentrations as well as associated size fractions of the detected MP. Over a 12 month period, samples were collected at three locations and analyzed across three particle size fractions (100−500 μm, 50−100 μm, and 10−50 μm) using thermalextraction desorption-gas chromatography/mass spectrometry (TED-GC/MS). The most prevalent polymers identified were polyethylene (PE), polypropylene (PP), polystyrene (PS), styrene−butadiene rubber (SBR), and natural rubber (NR). Statistical analyses, including principal component and cluster analysis, revealed size-dependent patterns,minor seasonal variation and spatial variations. These findings are particularly significant for ecotoxicological research and regulatory development, especially regarding tire abrasion a rarely quantified but potentially harmful MP source. The study contributes aluable data for future environmental monitoring and supports EU directives on wastewater and drinking water quality KW - TED-GC/MS KW - Microplastics KW - Environment KW - Monitoring KW - Reference data PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654669 DO - https://doi.org/10.1021/acsestwater.5c00530 SN - 2690-0637 SP - 1 EP - 10 PB - American Chemical Society (ACS) AN - OPUS4-65466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oskoei, Párástu A1 - Afonso, Rúben A1 - Bastos, Verónica A1 - Nogueira, João A1 - Keller, Lisa-Marie A1 - Andresen, Elina A1 - Saleh, Maysoon I. A1 - Rühle, Bastian A1 - Resch-Genger, Ute A1 - Daniel-da-Silva, Ana L. A1 - Oliveira, Helena T1 - Upconversion Nanoparticles with Mesoporous Silica Coatings for Doxorubicin Targeted Delivery to Melanoma Cells N2 - Melanoma is one of the most aggressive skin cancers and requires innovative therapeutic strategies to overcome the limitations of conventional therapies. In this work, upconversion nanoparticles coated with mesoporous silica and functionalized with folic acid (UCNP@mSiO2-FA) were developed as a targeted nanocarrier system for the delivery of doxorubicin (DOX). The UCNPs were synthesized via thermal decomposition, coated with mesoporous silica shells, and functionalized with folic acid (FA) to enable receptor-mediated targeting. DOX was then loaded into the mesoporous silica coating by adsorption, yielding UCNP@mSiO2-FA-DOX. The different UCNPs were characterized for size, composition, colloidal stability, and loading and release of DOX. This comprehensive physicochemical characterization confirmed a high DOX loading efficiency and a slightly increased drug release under acidic conditions, mimicking the tumour microenvironment. In vitro assays using four melanoma cell lines (A375, B16-F10, MNT-1, and SK-MEL-28) revealed an excellent biocompatibility of UCNP@mSiO2-FA and a significantly higher cytotoxicity of UCNP@mSiO2-FA-DOX compared to unloaded UCNPs, in a dose-dependent manner. Cell cycle analysis demonstrated G2/M phase arrest after treatment with UCNP@mSiO2-FA-DOX, confirming its antiproliferative effect. Overall, UCNP@mSiO2-FA-DOX represents a promising nanoplatform for targeted melanoma therapy, combining active tumour targeting and enhanced anticancer efficacy. KW - Fluorescence KW - Synthesis KW - Nano KW - Particle KW - Silica KW - Cell KW - Uptake KW - Drug KW - Characterization KW - DOX KW - Imaging KW - Toxicity KW - Release KW - pH PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653596 DO - https://doi.org/10.3390/molecules31010074 SN - 1420-3049 VL - 31 IS - 1 SP - 1 EP - 18 PB - MDPI AG AN - OPUS4-65359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grabicki, N. A1 - Nguyen, K. T. G. A1 - Weidner, Steffen A1 - Dumele, O. T1 - Confined Spaces in [n]Cyclo-2,7-pyrenylenes N2 - A set of strained aromatic macrocycles based on [n]cyclo2,7-(4,5,9,10-tetrahydro)pyrenylenes is presented with size dependent photophysical properties. The K-region of pyrene was functionalized with ethylene glycol groups to decorate the outer rim and thereby confine the space inside the macrocycle. This confined space is especially pronounced for n = 5, which leads to an internal binding of up to 8.0×104 M–1 between the ether-decorated [5]cyclo-2,7-pyrenylene and shape complementary crown ether–cation complexes. Both, the ether-decorated [n]cyclo-pyrenylenes as well as one of their host–guest complexes have been structurally characterized by single crystal X-ray analysis. In combination with computational methods the structural and thermodynamic reasons for the exceptionally strong binding have been elucidated. The presented rim confinement strategy makes cycloparaphenylenes an attractive supramolecular host family with a favorable, size-independent read-out signature and binding capabilities extending beyond fullerene guests. KW - Cycloparaphenylenes KW - Host–guest systems KW - Macrocycles KW - Molecular recognition KW - Supramolecular chemistry PY - 2021 DO - https://doi.org/10.1002/anie.202102809 SN - 1433-7851 VL - 60 IS - 27 SP - 1 EP - 7 PB - Wiley VCH AN - OPUS4-52517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa T1 - Examination of biological samples by means of single-cell ICP-ToF-MS N2 - Up to now, different analytical methods for single cell analysis exist focusing on key features such as size, shape, morphology and elemental composition. The combination of the latest ICP-MS techniques - ICP-ToF-MS - together with the latest developments in the field of sample delivery - micro droplet generator (MDG) – will allow a Deep insight into the composition and size of cells. Microbiologically influenced corrosion (MIC) is an oxidation of metals affected by the presence or activity (or both) of microorganisms e.g. Shewanella Putrefaciens in biofilms on the surface of the corroding material. As this can happen for example in the soil on iron pipes of water pipes, in oil tanks or on steel sheet piling, there is great interest in MIC research, not only from various industrial sectors, but also from the environmental aspect. T2 - SALSA - Make & Measure CY - Online Meeting DA - 15.10.2020 KW - SC-ICP-ToF-MS KW - Single cell analysis KW - MDG ICP-ToF-MS KW - Microdroplet generator PY - 2020 AN - OPUS4-52441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pollard, M. T1 - Functionalized Poly(ethylene glycol)s (PEGs) as a Reference Material for Detection of Polymeric end Groups via SEC Hyphenated with FTIR and 1H-NMR (80 MHz) N2 - With the online coupling (or hyphenation) of chemically-resolved spectroscopy detection with classical size-exclusion chromatography (SEC) it is possible to correlate polymer molecular size with chemical structure in a single in-situ or on-flow measurement. Medium-resolution 1H-NMR (60 MHz) spectroscopy (i.e., “desktop NMR”) and Fouriertransform Infrared Spectroscopy (FTIR) have both been developed as coupled methods (SEC-MR-NMR, SEC-FTIR) for the detection of polymer analytes by monitoring e.g. alkene or carbonyl functionality.1,2 Here, we have investigated the potential for the detection of polymer end groups, using a slightly higher field-strength spectrometer (80 MHz 1H Larmor frequency) and taking advantage of a columnless injection method that provides bulk spectra for reference. End-functionalized polymers were synthesized by reaction of PEG with toluene isocyanate, yielding ,-functionalized polymers with exactly 2 IR- and NMR-detectable functional groups per chain, as proven by MALD-TOF mass spectrometry. We have investigated the sensitivity (limit of detection) and spectral resolution for these functional groups in chloroform, THF, and water. Results have demonstrated a good feasibility for the simultaneous online detection of PEG backbone (M~4000 g/mol) and these end groups at the level of ca. 2 mol%. T2 - 33rd International Symposium on Chromatography CY - Budapest DA - 18.09.2022 KW - Size exclusion chromatography KW - Polyethyleneglycol KW - MALDI-TOF MS KW - NMR PY - 2022 AN - OPUS4-56716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kricheldorf, H. R. T1 - Reversible Polycondensations and the Jacobson-Stockmayer Theory N2 - Reversible polycondensations are polycondensations that include equilibration reactions at any stage of the process. Syntheses of Polyesters in bulk involving transesterification reactions and syntheses of polyamides in bulk involving transamidation are typical examples. In 1950, Jacobson and Stockmayer published a first theory of reversible polycondensations based on experimental studies with aliphatic polyesters.[1,2] They explained the reversibility by the reversible formation of cyclic oligomers and low molar mass polymers from an active chain end (so-called “back-biting”). The formation of cycles via end-to-end cyclization was excluded in agreement with Flory´s theory of irreversible polycondensations.[3] The reinvestigation of the Jacobson-Stockmayer experiments by the authors in combination with theoretical considerations shows that the JS theory is wrong. [4,5] It turned out that the experimental scenario is far from the reality. In real polycondensations, intermolecular equilibration is faster than “back-biting”, and end-to-end cyclization is quite normal. The revised theory of step-growth polymerization predicts that in the ideal case of 100% conversion, all reaction products are cycles, regardless, of whether the step-growth polymerization is reversible or not. T2 - Polycondensation 2024 CY - Lyon, France DA - 15.09.2024 KW - Polycondensation KW - Cyclisation KW - MALDI TOF MS PY - 2024 UR - https://polycond-2024.sciencesconf.org/ AN - OPUS4-61070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trimpin, Sarah A1 - Yenchick, Frank S. A1 - Lee, Chuping A1 - Hoang, Khoa A1 - Pophristic, Milan A1 - Karki, Santosh A1 - Marshall, Darrell D. A1 - Lu, I-Chung A1 - Lutomski, Corinne A. A1 - El-Baba, Tarick J. A1 - Wang, Beixi A1 - Pagnotti, Vincent S. A1 - Meher, Anil K. A1 - Chakrabarty, Shubhashis A1 - Imperial, Lorelei F. A1 - Madarshahian, Sara A1 - Richards, Alicia L. A1 - Lietz, Christopher B. A1 - Moreno-Pedraza, Abigail A1 - Leach, Samantha M. A1 - Gibson, Stephen C. A1 - Elia, Efstathios A. A1 - Thawoos, Shameemah M. A1 - Woodall, Daniel W. A1 - Jarois, Dean R. A1 - Davis, Eric T.J. A1 - Liao, Guochao A1 - Muthunayake, Nisansala S. A1 - Redding, McKenna J. A1 - Reynolds, Christian A. A1 - Anthony, Thilani M. A1 - Vithanarachchi, Sashiprabha M. A1 - DeMent, Paul A1 - Adewale, Adeleye O. A1 - Yan, Lu A1 - Wager-Miller, James A1 - Ahn, Young-Hoon A1 - Sanderson, Thomas H. A1 - Przyklenk, Karin A1 - Greenberg, Miriam L. A1 - Suits, Arthur G. A1 - Allen, Matthew J. A1 - Narayan, Srinivas B. A1 - Caruso, Joseph A. A1 - Stemmer, Paul M. A1 - Nguyen, Hien M. A1 - Weidner, Steffen A1 - Rackers, Kevin J. A1 - Djuric, Ana A1 - Shulaev, Vladimir A1 - Hendrickson, Tamara L. A1 - Chow, Christine S. A1 - Pflum, Mary Kay H. A1 - Grayson, Scott M. A1 - Lobodin, Vladislav V. A1 - Guo, Zhongwu A1 - Ni, Chi-Kung A1 - Walker, J. Michael A1 - Mackie, Ken A1 - Inutan, Ellen D. A1 - McEwen, Charles N. T1 - New Processes for Ionizing Nonvolatile Compounds in Mass Spectrometry: The Road of Discovery to Current State-of-the-Art N2 - This Perspective covers discovery and mechanistic aspects aswell as initial applications of novel ionization processes for use in massspectrometry that guided us in a series of subsequent discoveries, instrumentdevelopments, and commercialization. Vacuum matrix-assisted ionization onan intermediate pressure matrix-assisted laser desorption/ionization sourcewithout the use of a laser, high voltages, or any other added energy wassimply unbelievable, at first. Individually and as a whole, the variousdiscoveries and inventions started to paint, inter alia, an exciting new pictureand outlook in mass spectrometry from which key developments grew thatwere at the time unimaginable, and continue to surprise us in its simplisticpreeminence. We, and others, have demonstrated exceptional analyticalutility. Our current research is focused on how best to understand, improve, and use these novel ionization processes throughdedicated platforms and source developments. These ionization processes convert volatile and nonvolatile compounds from solid orliquid matrixes into gas-phase ions for analysis by mass spectrometry using, e.g., mass-selected fragmentation and ion mobilityspectrometry to provide accurate, and sometimes improved, mass and drift time resolution. The combination of research anddiscoveries demonstrated multiple advantages of the new ionization processes and established the basis of the successes that lead tothe Biemann Medal and this Perspective. How the new ionization processes relate to traditional ionization is also presented, as wellas how these technologies can be utilized in tandem through instrument modification and implementation to increase coverage ofcomplex materials through complementary strengths. KW - Mass spectrometry PY - 2024 DO - https://doi.org/10.1021/jasms.3c00122 SN - 1879-1123 VL - 35 IS - 12 SP - 2753 EP - 2784 PB - American Chemical Society (ACS) AN - OPUS4-61417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rösler, Alexander A1 - Weidner, Steffen A1 - Klamroth, Tillmann A1 - Müller, Axel H. E. A1 - Schlaad, Helmut T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents N2 - The kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. KW - MALDI-TOF MS KW - Anionic polymerization KW - β‐myrcene KW - Kinetics KW - Reaction order KW - Activation energy KW - Microstructure KW - Quantum chemical calculations PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630900 DO - https://doi.org/10.1002/pi.6772 SN - 1097-0126 SP - 1 EP - 8 PB - Wiley CY - New York, NY AN - OPUS4-63090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen T1 - Zwitterionic polymerization of glycolide catalyzed by pyridine N2 - The usefulness of various N- and P-based catalysts for syntheses of cyclic polyglycolide via zwitterionic polymerization of glycolide was examined. Most catalysts produced discolored, largely insoluble polyglycolides consisting of cycles and unidentified byproducts. Soluble, cyclic polyglycolides were obtained using neat pyridine as catalyst at 120 °C, 100 °C, 80 °C, and even at 60 °C. The number-average molecular weights were extremely low and depended slightly on the glycolide-to-pyridine ratio. Three different mass distributions of the cycles were detected by mass spectrometry, depending on the reaction conditions. The cyclic polyglycolides were also characterized by differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) measurements. The SAXS data in combination with the mass spectra indicate that the majority of the cycles form extended-ring crystallites KW - MALDI-TOF MS KW - Polylactide KW - Polymerization KW - Zitterions PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639748 DO - https://doi.org/10.1039/d5py00762c SN - 1759-9954 SP - 1 EP - 9 PB - Royal Society of Chemistry (RSC) AN - OPUS4-63974 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dalgic, Mete‐Sungur A1 - Kumar, Sourabh A1 - Weidner, Steffen T1 - Quantitative Analysis of Polymers by MALDI‐TOF Mass Spectrometry: Correlation Between Signal Intensity and Arm Number N2 - The signal intensities of linear and star‐shaped poly(L‐lactides) (PLA) and poly (ethylene oxides) (PEO) were compared to determine the influence of the number of arms on the ionization in matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. In this study, a variety of blends were prepared and investigated, including binary and ternary combinations of linear and star‐shaped polymers with similar molecular masses. The focus was on examining their intensity ratios. In equimolar binary PLA blends, polymer stars were observed to exhibit higher intensities than their linear counterparts. This result was supported by experiments with equimolar ternary PLA blends, which clearly demonstrated an intensity dependence on the number of polymer arms. It was observed that four‐arm PLA exhibited higher intensities than three‐arm PLA. A similar trend was observed in investigations involving acetylated polymer end groups, suggesting that differences in ionization are primarily influenced by polymer architecture rather than end groups. In order to validate this assumption, the binding energies for [polymer‐K] + adduct ions utilizing the most stable geometry obtained from GOAT (Global Optimizer Algorithm) were calculated, revealing that star‐shaped lower mass oligomers have slightly higher binding energies. KW - MALDI-TOF MS KW - Starlike polymers KW - Quantification KW - Topology PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653401 DO - https://doi.org/10.1002/jms.70023 SN - 1076-5174 VL - 61 IS - 1 SP - 1 EP - 12 PB - John Wiley & Sons Ltd. AN - OPUS4-65340 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rösler, Alexander A1 - Weidner, Steffen A1 - Klamroth, Tillmann A1 - Müller, Axel HE A1 - Schlaad, Helmut T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. KW - Myrcene KW - Anionic polymerization KW - MALDI TOF MS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649039 DO - https://doi.org/10.1002/pi.6772 SN - 0959-8103 SP - 1 EP - 8 PB - Wiley AN - OPUS4-64903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Monikh, Fazel A. A1 - Materić, Dušan A1 - Valsami-Jones, Eugenia A1 - Grossart, Hans-Peter A1 - Altmann, Korinna A1 - Holzinger, Rupert A1 - Lynch, Iseult A1 - Stubenrauch, Jessica A1 - Peijnenburg, Willie T1 - Challenges in studying microplastics in human brain N2 - Human exposure to microplastics and nanoplastics (MNPs) is an emerging concern with potential implications for health. As awareness of this issue grows, it has prompted increasing scientific attention toward understanding if, and how, MNPs accumulate in human tissues. In a recent study, Nihart et al.1 used the analytical technique of pyrolysis gas chromatography–mass spectrometry (Py-GC–MS) to detect MNPs in human liver, kidney and brain, reporting the highest concentrations in the brain, with polyethylene as the predominant polymer. The study as reported appears to face methodological challenges, such as limited contamination controls and lack of validation steps, which May affect the reliability of the reported concentrations. In this Matters Arising, we highlight methodological limitations that have General relevance for advancing robust and reproducible MNP detection in human biomonitoring studies. KW - Microplastics KW - Nanoplastics KW - Py-GC-MS PY - 2025 DO - https://doi.org/10.1038/s41591-025-04045-3 SN - 1078-8956 VL - 31 IS - 12 SP - 1 EP - 3 PB - Springer Science and Business Media LLC AN - OPUS4-64698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen T1 - Polymerization of L‐Lactide Catalyzed by Metal Acetylacetonate Complexes N2 - ABSTRACTRing‐opening polymerizations (ROPs) of l‐lactide (LA) were performed at 120°C, 140°C, 150°C, and 180°C in bulk catalyzed by acetylacetonate (acac) complexes of manganese(II), nickel(II), copper(II), zirconium(IV), dibutyltin(IV), and vanadyl(V). These experiments revealed that only the acac complexes of Zr and Bu2Sn were reactive enough to enable quantitative polymerization within a few hours. Further ROPs with Bu2Sn(acac)2 and Zr(acac)4 showed that Bu2Sn(acac)2 had a slightly lower reactivity than the Zr complex. The ROPs catalyzed with Zr(acac)4 yielded number average molecular weights (Mn) up to 70,000 g mol−1. The matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectra indicated an exclusive formation of cycles in the mass range of up to m/z 13,000 for Zr(acac)4 and up to m/z 18,000 for Bu2Sn(acac)2. Unusually high melting temperatures (187°C–192°C) were also achieved along with high crystallinities. Furthermore, four lactide/glycolide copolymerizations catalyzed by Zr(acac)4 were performed, and the topology and the extent of transesterification were characterized by MALDI‐TOF mass spectrometry and 13C NMR spectroscopy. KW - MALDI-TOF MS KW - Polycondensation KW - Acetylacetonate PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639754 DO - https://doi.org/10.1002/pol.20250788 SN - 2642-4150 SP - 1 EP - 9 PB - Wiley Periodicals LLC. AN - OPUS4-63975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dalgic, Mete-Sungur A1 - Weidner, Steffen T1 - Solvent-free sample preparation for matrix-assisted laserdesorption/ionization time-of-flight mass spectrometry ofpolymer blends N2 - Solvent-free sample preparation offers some advantages over solvent-based techniques, such as improved accuracy, reproducibility and sensitivity, for matrix-assisted laser desorption/ionization (MALDI) analysis. However, little or no information is available on the application of solvent-free techniques for the MALDI analysis of polymer blends. Solvent-free sample preparation by ball milling was applied with varying sample-to-matrix ratios for MALDI time-of-flight mass spectrometry analysis of various polymers, including polystyrenes, poly(methyl methacrylate)s and poly(ethylene glycol)s. The peak intensity ratios were compared with those obtained after using the conventional dried droplet sample preparation method. In addition, solvent-assisted milling was also applied to improve sample homogeneities. Depending on the sample preparation method used, different peak intensity ratios were found, showing varying degrees of suppression of the signal intensities of higher mass polymers. Ball milling for up to 30 min was required to achieve constant intensity ratios indicating homogeneous mixtures. The use of wet-assisted grinding to improve the homogeneity of the blends was found to be disadvantageous as it caused partial degradation and mass-dependent segregation of the polymers in the vials.The results clearly show that solvent-free sample preparation must be carefully considered when applied to synthetic polymer blends, as it may cause additional problems with regard to homogeneity and stability of the blends. KW - MALDI TOF MS KW - Sample preparation KW - Polymer blends KW - Solvent-free PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598570 DO - https://doi.org/10.1002/rcm.9756 SN - 0951-4198 VL - 38 IS - 12 SP - 1 EP - 9 PB - Wiley online library AN - OPUS4-59857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diehn, S. A1 - Zimmermann, B. A1 - Tafintseva, V. A1 - Seifert, S. A1 - Bagcioglu, M. A1 - Ohlson, M. A1 - Weidner, Steffen A1 - Fjellheim, S. A1 - Kohler, A. A1 - Kneipp, Janina T1 - Combining Chemical Information From Grass Pollen in Multimodal Characterization N2 - The analysis of pollen chemical composition is important to many fields, including agriculture, plant physiology, ecology, allergology, and climate studies. Here, the potential of a combination of different spectroscopic and spectrometric methods regarding the characterization of small biochemical differences between pollen samples was evaluated using multivariate statistical approaches. Pollen samples, collected from three populations of the grass Poa alpina, were analyzed using Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, surface enhanced Raman scattering (SERS), and matrix assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). The variation in the sample set can be described in a hierarchical framework comprising three populations of the same grass species and four different growth conditions of the parent plants for each of the populations. Therefore, the data set can work here as a model system to evaluate the classification and characterization ability of the different spectroscopic and spectrometric methods. ANOVA Simultaneous Component Analysis (ASCA) was applied to achieve a separation of different sources of variance in the complex sample set. Since the chosen methods and sample preparations probe different parts and/or molecular constituents of the pollen grains, complementary information about the chemical composition of the pollen can be obtained. By using consensus principal component analysis (CPCA), data from the different methods are linked together. This enables an investigation of the underlying global information, since complementary chemical data are combined. The molecular information from four spectroscopies was combined with phenotypical information gathered from the parent plants, thereby helping to potentially link pollen chemistry to other biotic and abiotic parameters. KW - Pollen KW - MALDI-TOF MS KW - FTIR KW - Raman KW - Multivariate analyses PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504822 DO - https://doi.org/10.3389/fpls.2019.01788 VL - 10 SP - 1788 AN - OPUS4-50482 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen A1 - Scheliga, F. T1 - Synthesis of cyclic polymers and flaws of the Jacobson–Stockmayer theory N2 - Cyclic poly(L-lactide)s were prepared by ring-opening polymerization combined with simultaneous polycondensation (ROPPOC) in bulk at 160 ° with dibutyltin bis(4-cyanophenoxide) as catalyst. It is demonstrated by MALDI TOF mass spectrometry and 1H NMR end group analyses that cycles are formed by endto-end cyclization in addition to “back-biting” transesterification. Formation of high molar mass cyclic poly L-lactide)s by means of several more reactive ROPPOC catalysts presented previously and in new experiments is discussed. These experimental results, together with theoretical arguments, prove that part of the Jacobson–Stockmayer theory is wrong. The critical monomer concentration, above which end-toend cyclization is seemingly impossible, does not exist and reversible like irreversible polycondensations can theoretically proceed up to 100% conversion, so that finally all reaction products will necessarily adopt a cyclic architecture. KW - Polylactide KW - MALDI-TOF MS KW - Cyclization PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506419 DO - https://doi.org/10.1039/d0py00226g VL - 11 IS - 14 SP - 2595 EP - 2604 PB - Royal Society for Chemistry AN - OPUS4-50641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martins, Ines A1 - Al-Sabbagh, Dominik A1 - Bentrup, U. A1 - Marquardt, Julien A1 - Schmid, Thomas A1 - Scoppola, E. A1 - Kraus, Werner A1 - Stawski, Tomasz A1 - de Oliveira Guilherme Buzanich, Ana A1 - Yusenko, Kirill A1 - Weidner, Steffen A1 - Emmerling, Franziska T1 - Formation Mechanism of a Nano-Ring of Bismuth Cations and Mono-Lacunary Keggin-Type Phosphomolybdate N2 - A new hetero-bimetallic polyoxometalate (POM) nano-ring was synthesized in a one-pot procedure. The structure consists of tetrameric units containing four bismuth-substituted monolacunary Keggin anions including distorted [BiO8] cubes. The nano-ring is formed via self-assembly from metal precursors in aqueous acidic medium. The compound (NH4)16[(BiPMo11O39)4] ⋅ 22 H2O; (P4Bi4Mo44) was characterized by single-crystal X-ray diffraction, extended X-ray absorption fine structure spectroscopy (EXAFS), Raman spectroscopy, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF), and thermogravimetry/differential scanning calorimetry mass spectrometry (TG-DSC-MS). The formation of the nano-ring in solution was studied by time-resolved in situ small- and wide-angle X-ray scattering (SAXS/WAXS) and in situ EXAFS measurements at the Mo−K and the Bi−L3 edge indicating a two-step process consisting of condensation of Mo-anions and formation of Bi−Mo-units followed by a rapid self-assembly to yield the final tetrameric ring structure. KW - Bismuth KW - In situ EXAFS KW - In situ SAXS/WAXS KW - Lacunary Keggin ion KW - Polyoxometalates KW - Self-assembly PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546823 DO - https://doi.org/10.1002/chem.202200079 SN - 0947-6539 VL - 28 IS - 27 SP - 1 EP - 7 PB - Wiley-VCH CY - Weinheim AN - OPUS4-54682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grimmer, Christoph A1 - Richter, Matthias A1 - Neuhaus, T. A1 - Prinz, Carsten A1 - Strzelczyk, Rebecca Skadi A1 - Colakoglu, Irem A1 - Horn, Wolfgang T1 - Towards a multi-VOC emission reference material with temporally constant emission profile for QA/QC of materials emission testing procedures N2 - Emission reference materials (ERMs) are sought after to further control and improve indoor air quality. The impregnation of porous materials with volatile organic compounds (VOCs) is a promising approach to produce ERMs. Different VOCs were used to impregnate various porous materials (mainly zeolites, activated carbons and a metal organic framework). The influence of different methodological parameters and material properties were studied to optimize the impregnation procedure and to find the best material/VOC combination. The impregnation procedure remains quite irreproducible, nevertheless, very good ERM candidates were identified. Two materials (zeolite 4 and AC 1 impregnated with n-hexadecane) showed a very stable emission over 14 days (<10 % change). Another material (AC 1 impregnated with toluene) showed a declining emission profile but with a very good in-batch reproducibility and a storage stability of up to 12 months. KW - Emission reference material KW - Porous materials KW - Indoor air quality KW - Emission test chamber KW - CO2 assisted impregnation KW - EN 16516 PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612238 DO - https://doi.org/10.1016/j.chemosphere.2024.143437 SN - 1879-1298 VL - 366 SP - 1 EP - 8 PB - Elsevier AN - OPUS4-61223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Results of the Plastic in the environment comparative test N2 - The talk describes the sturcture and the results of the "plastics in the environment" comparative test of 2019. T2 - Symposium "Challenges of microplastic analysis – Bridging state of the art and policy needs” CY - Online meeting DA - 09.09.2021 KW - Microplastic KW - Comparative test KW - ILC PY - 2021 AN - OPUS4-53236 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Smales, Glen J. A1 - Appel, Paul Alexander A1 - Breßler, Ingo A1 - Chambers, Aaron A1 - Dumele, Oliver A1 - Ebisch, Maximilian A1 - Frontzek, Julius A1 - del Refugio Monroy, José A1 - Rosalie, Julian M. A1 - Pauw, Brian R. T1 - DACHS and RoWaN: The Automated and Traceable Synthesis of ZIF-8 N2 - Automated synthesis and open-data practices are increasingly seen as key enablers of transparent, traceable, and reproducible science. By combining automation with structured, metadata-rich documentation, it becomes possible to systematically com- pare synthesis strategies and link outcomes to detailed parameters. In this work, we implement such an approach to study the synthesis of ZIF-8, comparing hand and automation-assisted methods under controlled conditions. Using over 100 synthesis experiments, we assess the repeatability of particle size and yield, and explore how variations in mixing and injection influence outcomes. This study demonstrates how traceable synthesis workflows can support repeatability and comparison across synthe- sis strategies. The DACHS (Database for Automation, Characterization and Holistic Synthesis) framework underpins this work, providing a lightweight infrastructure for transparent synthesis data capture. KW - Automation KW - MOFs KW - SAXS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-645861 DO - https://doi.org/10.26434/chemrxiv-2025-7fgg0 SP - 1 EP - 32 PB - Cambridge AN - OPUS4-64586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Holistic Experimentation in the HExX-Lab N2 - Through bottom-up, comprehensive digitalisation of all aspects of an experiment, the HEX-lab improves the trustworthiness (traceability, reproducibility, quality) of scientific findings. The five main parts that make up a materials science experiment, i.e. Sample preparation, Measurements, Processing, Analysis, and Interpretation, each have been addressed in thorough and unique ways in this lab, building up a foundation for a wide range of materials science collaborations. Improvements span the spectrum. Hardware developments include new sample environments and stages, such as grazing incidence motion towers, electrochemistry cells and flow-through holders, electronic components such as safety interlocks and multipurpose I/O controllers, and liquid handling systems such as coolant flow cross-over systems. Software developments include: 1) a new comprehensive control system operating on both the RoWaN as well as the MOUSE allowing for full Python control and sequencing of all experimentation, 2) Automated scripts for instrument optimization, sample alignments and measurements, 3) revamped data pipelines and analysis software, standalone or launched as part of operations sequencing dashboards on servers, and 4) meticulously structured archival datafiles, fully documenting sample preparation, measurements, processing and analyses. These allow for holistic databases and dashboards to be constructed to investigate the links between synthesis parameters and resulting morphology. This poster will highlight some of the tools and techniques developed and available in the HEX-lab over the years, from sample environments to overarching experiment and data organisation structures. T2 - Materials Science Core Facility Synergy Forum 2025 CY - Bremen, Germany DA - 26.02.2025 KW - Digitalization KW - Holistic experiments KW - Traceability KW - Data provenance PY - 2025 AN - OPUS4-62675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chabbah, T. A1 - Chatti, S. A1 - Jaffrezic-Renault, N. A1 - Weidner, Steffen A1 - Marestin, C. A1 - Mercier, R. T1 - Impedimetric sensors based on diethylphosphonate-containingpoly(arylene ether nitrile)s films for the detection of lead ions N2 - This article describes the elaboration and characterization of diethylphosphonate-containing polymers coated electrodes as sensors for the detection of heavy metalstraces, by electrochemical impedance spectroscopy. Diethylphosphonate groupswere chosen as heavy metals binding sites. Two different series of polymers bearingthese anchoring groups were synthesized. Whereas the diethylphosphonate groupsare directly incorporated in the aromatic macromolecular chain in some polymers, analiphatic spacer is removing the chelating site from the polymer backbone in others.The influence of the macromolecular structure on the sensing response was studied,especially for the detection of Pb2+,Ni2+,Cd2+and Hg2+. Polymer P6, including thehigher amount of diethylphosphonate groups removed from the polymer chain by ashort alkyl spacer gave the higher sensitivity of detection of lead ions, with a detec-tion limit of 50 pM KW - Heavy metals KW - Phosphonate esters KW - Lead ions KW - MALDI TOF MS PY - 2023 DO - https://doi.org/10.1002/pat.6065 SN - 1042-7147 SP - 1 EP - 11 PB - John Wiley & Sons, Ltd AN - OPUS4-57356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa T1 - Deciphering corrosion processes of MIC organisms - single cell-ICP-ToF-MS analysis of archaea on solid steels N2 - ICP-ToF (time of flight) MS enables the analysis of the multi-element fingerprint of single cells. The single cell ICP-ToF-MS is used in the presented poster for the analysis of archaea involved in microbiologically influenced corrosion (MIC) of steel. By means of sc-ICP-ToF-MS, the possible uptake of individual elements from the respective steel is investigated - the information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts. The work combines modern methods of analytical sciences with materials. T2 - SALSA - Make & Measure 2021 CY - Online meeting DA - 16.09.2021 KW - Sc-ICP-ToF-MS KW - Single cell analysis KW - Microbiologically influenced corrosion KW - Archaea KW - Poster presentation PY - 2021 AN - OPUS4-53337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falkenhagen, Jana A1 - Dalgic, Mete-Sungur A1 - Weidner, Steffen T1 - Quantitative MALDI-TOF Mass Spectrometry of Star-Shaped Polylactides Based on Chromatographic Hyphenation N2 - The end groups of three- and four-arm star-shaped polylactides (PLA) with trimethylolpropane and pentaerythritol core structures were functionalized with acetic acid. Reaction products with different degrees of functionalization were analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Additional gradient elution liquid adsorption chromatography (GELAC) measurements were performed to determine the degree of functionalization. This technique enabled clear separation and sufficient quantification of the formed species. These chromatographic data could be used inversely to quantify mass spectrometric results, which are usually biased by the unknown ionization probabilities of different polymer end group structures. Our results showed that, in this particular case, the peak intensity in the MALDITOF mass spectra can be used to semiquantitatively determine the degree of functionalization in incompletely functionalized multiarm PLA. KW - Polylactides KW - MALDI-TOF-MS KW - Gradient elution liquid adsorption chromatography PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625292 DO - https://doi.org/10.1021/jasms.4c00491 SN - 1879-1123 SP - 1 EP - 9 PB - American Chemical Society (ACS) AN - OPUS4-62529 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fink, Friedrich A1 - Stawski, Tomasz M. A1 - Emmerling, Franziska A1 - Falkenhagen, Jana T1 - A novel machine-learning approach to unlock technical lignin classification by NIR spectroscopy - bench to handheld N2 - In this research, the utilization of near-infrared (NIR) spectroscopy in conjunction with advanced machine learning methods is investigated for categorizing technical lignins obtained from different biomass sources and industrial procedures. Technical lignins, such as kraft, organosolv and lignosulfonates, have different chemical compositions, which continue to make uniform characterization and application in sustainable sectors extremely difficult. Fast, universally accessible analytics combined with data analysis is still an open question. For the first time three distinct NIR spectrometers—a high-performance benchtop system, a mid-priced compact device, and an economical handheld unit—were utilized to record NIR spectra of 31 unique lignin samples. The spectra underwent pre-processing through standard normal variate (SNV) transformation and Savitzky-Golay derivatives to amplify spectral features and decrease noise. Principal component analysis (PCA) was employed to reduce data complexity and extract crucial characteristics for classification purposes. Subsequently, four machine learning algorithms—Support Vector Machines (SVM), Gaussian Naive Bayes (GNB), Gaussian Process Classification (GPC), and Decision Tree Classification (DTC)—were implemented for the classification of the lignin samples. The DTC model exhibited the highest accuracy among them across different spectrometers. Although the benchtop spectrometer produced the most precise outcomes, the compact NeoSpectra system also displayed potential as a cost-efficient option. Nonetheless, the restricted spectral coverage of the handheld NIRONE spectrometer resulted in reduced classification accuracy. Our discoveries highlight the capability of NIR spectroscopy, combined with robust data analysis techniques, for the swift and non-destructive classification of technical lignins, facilitating their improved utilization in sustainable fields. KW - Technical lignins KW - NIR spectroscopy KW - Classification KW - Machine-learning KW - PCA PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634518 DO - https://doi.org/10.1016/j.chemolab.2025.105467 SN - 0169-7439 VL - 264 SP - 1 EP - 10 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-63451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Meyer, Andreas A1 - Falkenhagen, Jana A1 - Kricheldorf, Hans R. T1 - Cyclic polyglycolide by means of metal acetylacetonates N2 - Glycolide was polymerized in bulk at 160 °C using various metal acetylacetonates as catalysts. Zirconium acetylacetonate was particularly efficient, enabling rapid polymerization even at 130 °C. The formation of cyclic poly(glycolic acid) (PGA), most likely via a ring-expansion polymerization (REP) mechanism, was proven by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Depending on the polymerization conditions, the formation of even-numbered cycles was favored to varying degrees. Number-average molecular weights (Mn) in the range of 2000–3500 g mol−1 were achieved with dispersities below 2.0. Wide-angle X-ray scattering (WAXS) powder patterns showed that the crystal lattice was the same as that of known linear PGAs, regardless of the Mn values. These patterns enabled a comparison of crystallinities with values derived from DSC measurements. KW - MALDI-TOF MS KW - Polyglycolide KW - Crystallization KW - Small-angle X-ray scattering KW - Cyclization PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653731 DO - https://doi.org/10.1039/d5ra07961f SN - 2046-2069 VL - 16 IS - 2 SP - 1757 EP - 1764 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65373 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 - JOUR A1 - Bartczak, Dorota A1 - Sikora, Aneta A1 - Goenaga-Infante, Heidi A1 - Altmann, Korinna A1 - Drexel, Roland A1 - Meier, Florian A1 - Alasonati, Enrica A1 - Lelong, Marc A1 - Cado, Florence A1 - Chivas-Joly, Carine A1 - Fadda, Marta A1 - Sacco, Alessio A1 - Rossi, Andrea Mario A1 - Pröfrock, Daniel A1 - Wippermann, Dominik A1 - Barbero, Francesco A1 - Fenoglio, Ivana A1 - Booth, Andy M. A1 - Sørensen, Lisbet A1 - Igartua, Amaia A1 - Wouters, Charlotte A1 - Mast, Jan A1 - Barbaresi, Marta A1 - Rossi, Francesca A1 - Piergiovanni, Maurizio A1 - Mattarozzi, Monica A1 - Careri, Maria A1 - Caebergs, Thierry A1 - Piette, Anne-Sophie A1 - Parot, Jeremie A1 - Giovannozzi, Andrea Mario T1 - Multiparameter characterisation of a nano-polypropylene representative test material with fractionation, light scattering, high-resolution microscopy, spectroscopy, and spectrometry methods N2 - Reference and quality control materials with comparable physicochemical properties to nanoplastic contaminants present in environmental and food nanoplastics are currently lacking. Here we report a nanoplastic polypropylene material prepared using a top-down approach involving mechanical fragmentation of larger plastics. The material was found to be homogeneous and stable in suspension and has been characterised for average particle size, size distribution range, particle number concentration, polypropylene mass fraction and inorganic impurity Content using a wide range of analytical methods, including AF4, cFFF, PTA, (MA)DLS, MALS, SEM, AFM, TEM, STEM, EDS,Raman, ICP-MS and pyGC-MS. The material was found to have a broad size distribution, ranging from 50 nm to over 200 nm, with the average particle size value dependent on the technique used to determine it. Particle number concentration ranged from 1.7–2.4 × 1010 g−1 , according to PTA. Spectroscopy techniques confirmed that the material was polypropylene, with evidence of aging due to an increased level of oxidation. The measured mass fraction was found to depend on the marker used and ranged between 3 and 5 μg g−1 . Inorganic impurities such as Si, Al, Mg, K, Na, S, Fe, Cl and Ca were also identified at ng g−1 levels. Comparability and complementarity across the measurement methods and techniques is also discussed. KW - Polypropylene KW - Nanoplastics KW - Analytics KW - Reference material KW - Scattering methods PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654680 DO - https://doi.org/10.1039/D5EN00917K SN - 2051-8153 SP - 1 EP - 15 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoque, Maroof Arshadul A1 - Sommerfeld, Thomas A1 - Lisec, Jan A1 - Das, Prasenjit A1 - Prinz, Carsten A1 - Heinekamp, Christian A1 - Stolar, Tomislav A1 - Etter, Martin A1 - Rosenberger, David A1 - George, Janine A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska T1 - Mechanochemically Synthesized Covalent Organic Framework Effectively Captures PFAS Contaminants N2 - Per‐ and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that pose significant health risks, prompting urgent efforts to develop effective removal methods and adsorbers. Covalent organic frameworks (COFs) are metal‐free adsorbers with high stability and tunable porosity. A highly crystalline COF is synthesised mechanochemically using 1,3,5‐tris(4‐aminophenyl)benzene (TAPB) and 1,3,5‐triformylbenzene (TFB). The formation dynamics are monitored in real time with time‐resolved in situ synchrotron X‐ray diffraction. The TAPB‐TFB COF demonstrates good efficiency in eliminating PFAS from water. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are effectively extracted, and most of the adsorption occurred within the first 10 min. Additionally, X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and DFT calculations are employed to elucidate the molecular interactions between PFAS and the COF framework. The rapid and efficient removal of PFAS makes TAPB‐TFB COF a promising material for water treatment applications. KW - COFs KW - Ball-milling KW - PFAS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648712 DO - https://doi.org/10.1002/smll.202509275 SN - 1613-6810 VL - 21 IS - 44 SP - 1 EP - 8 PB - Wiley CY - Weinheim AN - OPUS4-64871 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael T1 - Processing and application properties of multiple principal element alloys (MPEA) N2 - The presentation gives an overview of BAM's activities on processing influences and application properties of MPEAs in the form of joined and machined high and medium entropy alloys (CoCrFeMnNi and CoCrNi). In the case of welding, the focus is on defect-free welded joints with sufficient mechanical properties. In the case of machining, the focus is on the possible influence on the surface quality of the materials through adequate milling parameters. In addition, the hydrogen absorption and diffusion properties as well as the electrochemical corrosion behavior are fundamentally examined. T2 - FAU-Department Werkstoffwissenschaften, Seminar: Aktuelle Probleme der Werkstoffwissenschaften CY - Erlangen, Germany DA - 25.04.2024 KW - Welding KW - Application properties KW - Machining KW - High-entropy alloy KW - Hydrogen PY - 2024 AN - OPUS4-59975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Separation of polysterene nanoparticles with different coatings using 2D off-line coupling of asymmetrical flow field flow fractionation and capillary electrophoresis N2 - The successful off-line coupling of asymmetrical flow field flow fractionation (AF4) and capillary electrophoresis (CE) for Separation of nanoparticles (NPs) with different surface coatings was shown. Two mixtures of polystyrene nanoparticles (PS-NPs) with comparable core sizes (20 nm and 50 nm) but different coatings (no coating/carboxyl-coated) were studied. Separation in either method resulted in non-baseline resolved or non-separated peaks. In contrast, two-dimensional off-line coupling of AF4 and CE resulted in clearly separated regions in their 2 D plots and can obviouly improve separation resolution. T2 - FFF 2020 CY - Wien, Austria DA - 23.02.2020 KW - Capillary electrophoresis KW - Nanoparticle PY - 2020 AN - OPUS4-50487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - You, Zengchao A1 - Nirmalananthan-Budau, Nithiya A1 - Resch-Genger, Ute A1 - Panne, Ulrich A1 - Weidner, Steffen T1 - Separation of polystyrene nanoparticles bearing different carboxyl group densities and functional groups quantification with capillary electrophoresis and asymmetrical flow field flow fractionation N2 - Two sets of polystyrene nanoparticles (PSNPs) with comparable core sizes but different carboxyl group densities were made and separated using asymmetric flow field flow fractionation (AF4), capillary electrophoresis (CE), and the off-line hyphenation of both methods. Our results revealed the significant potential of two-dimensional off-line AF4-CE hyphenation to improve the separation and demonstrated for the first time, the applicability of CE to determine the functional group density of nanoparticles (NPs). Compared to the result acquired with conductometric titration, the result obtained with synthesized 100 nm sized PSNPs revealed only a slight deviation of 1.7%. Commercial 100 nm sized PSNPs yielded a deviation of 4.6 %. For 60 nm sized PSNPs, a larger deviation of 10.6 % between both methods was observed, which is attributed to the lower separation resolution. KW - Nanoparticle KW - A4F KW - Capillary electrophoresis KW - Carboxyl group PY - 2020 DO - https://doi.org/10.1016/j.chroma.2020.461392 VL - 1626 SP - 461392 PB - Elsevier B.V. AN - OPUS4-51080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Recknagel, Sebastian A1 - Richter, Silke A1 - Hoppe, Marion A1 - Meckelburg, Angela A1 - Prinz, Carsten A1 - Roik, Janina A1 - Abad Andrade, Carlos Enrique T1 - Powering precision: development of a certified reference material for elemental composition analysis of lithium nickel manganese cobalt oxide (Li-NMC) cathode material for lithium-ion batteries N2 - This work presents the development and certification of the world’s first certified reference material (CRM), BAM-S014, for a lithium nickel manganese cobalt oxide (LiNi0.33Mn0.33Co0.33O2 or Li-NMC 111) cathode material—an integral component in high-energy-density lithium-ion batteries that power electric vehicles (EVs), portable electronics, and stationary energy storage systems. By providing certified mass fractions for 11 elements, this CRM addresses a critical need for accurate and traceable elemental analysis, supporting quality control and regulatory compliance in the global battery industry. Ensuring reliable and harmonized measurements supports the efficient use of resources, including the reuse of recycled materials, and ultimately helps maintain product performance and safety. The values were assigned through an interlaboratory comparison involving 16 participating laboratories and various analytical techniques such as inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF) spectrometry, and combustion analysis. In addition to chemical characterization, the certification process includes homogeneity and stability testing of the candidate material. Details are provided on the analytical methods used for chemical characterization and the calculation of the uncertainties of the certified mass fractions. In addition to detailing the development of the CRMs, this work provides an overview of ongoing standardization activities in Li-component analysis, thereby guiding the calibration of analytical methods and contributing to the establishment of globally accepted standards for evaluating energy storage materials and advancing sustainable mobility and clean energy solutions. KW - Certified reference material KW - Lithium nickel manganese cobalt oxide KW - LNMC KW - Lithium-ion battery KW - Cathode material PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643763 DO - https://doi.org/10.1007/s00216-025-05766-7 SN - 1618-2642 VL - 417 IS - 12 SP - 2643 EP - 2653 PB - Springer Nature AN - OPUS4-64376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Valentim Gelamo, Rogério A1 - Bueno Leite, Natália A1 - de Sousa Amadeu, Nader A1 - Reis Pedreira Muniz Tavares, Michel A1 - Oberschmidt, Dirk A1 - Klemm, Sophie A1 - Fleck, Claudia A1 - Cakir, Cafer-Tufan A1 - Radtke, Martin A1 - Aparecido Moreto, Jéferson T1 - Exploring the Nb2O5 coating deposited on the Ti-6Al-4V alloy by a novel GE-XANES technique and nanoindentation load-depth N2 - This research group has been demonstrating the significant advantages of using Nb2O5 coatings for functionalizing titanium, aluminium, and stainless steels. Regarding the biomedical sector and considering Ti-6Al-4V alloy, the reactive sputtering technique improved the cell viability, the osteogenic performance of cells involved in the osseointegration process as well as the ability to delay bacterial proliferation. The characteristics of the Nb2O5 coatings were assessed before by using standard methods, which provide information only a few tens of nanometers depth. Given that the Nb2O5 coating fabricated in this work exhibits a thickness of approximately 300 nm, the GE-XANES technique emerges as the most suitable method for this analysis. Additional information was provided with the aid of nanoindentation load-depth (P-h) curves. GE-XANES results indicated the formation of a homogeneous layer of Nb2O5 coating on the Ti-6Al-4V surfaces. The deposition process improved the surface hardness of the Ti-6Al-4V alloy (4.38 GPa versus 5.62 GPa) considering the 2 mN load. KW - BAMline KW - GE-XANES KW - Synchrotron PY - 2024 DO - https://doi.org/10.1016/j.matlet.2023.135584 SN - 0167-577X VL - 355 SP - 1 EP - 4 PB - Elsevier B.V. AN - OPUS4-60835 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kossatz, Philipp A1 - Mezhov, Alexander A1 - Andresen, Elina A1 - Prinz, Carsten A1 - Schmidt, Wolfram A1 - Resch-Genger, Ute T1 - Assessing the Applicability of Lanthanide-Based Upconverting Nanoparticles for Optically Monitoring Cement Hydration and Tagging Building Materials N2 - Chemically stable, lanthanide-based photon upconversion micro- and nanoparticles (UCNPs) with their characteristic multicolor emission bands in the ultraviolet (UV), visible (vis), near-infrared (NIR), and short-wave infrared (SWIR) arepromising optical reporters and barcoding tags. To assess the applicability of UCNPs for the monitoring of early stage cement hydration processes and as authentication tags for cementitious materials, we screened the evolution of the luminescence of Selfmade core-only NaYF4:Yb,Er UCNPs and commercial μm-sized Y2O2S:Yb,Er particles during the first stages of cement hydration, which largely determines the future properties of the hardened material. Parameters explored from the UCNP side included particle size, morphology, surface chemistry or coating, luminescence properties, and concentration in different cement mixtures. From the cement side, the influence of the mineral composition of the cement matrix was representatively examined for ordinary Portland cement (OPC) and its constituents tricalcium aluminate (C3A), tricalcium silicate (C3S), and gypsum at different water to cement ratios. Based on reflection and luminescence measurements, enabling online monitoring, which were complemented by XRD and isothermal heat-flow calorimetric measurements to determine whether the incorporation of these particles could impair cement hydration processes, well suited lanthanide particle reporters could be identified as well as application conditions. In addition, thereby the reporter influence on cement hydration kinetics could be minimized while still preserving a high level of information content. The best performance for the luminescence probing of changes during early stage cement hydration processes was observed for 25 nm-sized oleate (OA)-coated UCNPs added in a concentration of 0.1 wt %. Higher UCNP amounts of 1.0 wt % delayed cement hydration processes size- and surface coatingspecifically in the first 24 h. Subsequent luminescence stability screening studies performed over a period of about one year support the applicability of UCNPs as optical authentication tags for construction materials. KW - Quality assurance KW - Fluorescence KW - Nano KW - Particle KW - Synthesis KW - Quantum yield KW - NIR KW - Mechanism KW - Characterization KW - XRD KW - Calorimetry KW - Advanced material KW - Cement KW - Monitoring KW - Surface KW - Size KW - Lifetime KW - Barcode KW - Lanthanide KW - Upconversion KW - Encoding KW - Method PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638318 DO - https://doi.org/10.1021/acsomega.5c02236 SN - 2470-1343 VL - 10 IS - 29 SP - 31587 EP - 31599 PB - ACS Publications CY - Washington, DC AN - OPUS4-63831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Yusenko, Kirill A1 - Stawski, Tomasz A1 - Kulow, Anicó A1 - Cakir, Cafer Tufan A1 - Röder, Bettina A1 - Naese, Christoph A1 - Britzke, Ralf A1 - Sintschuk, Michael A1 - Emmerling, Franziska T1 - BAMline - A real-life sample materials research beamline N2 - With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. The BAMline, a real-life sample materials research beamline, provides unique insights into materials’ electronic and chemical structure at different time and length scales. The beamline specializes in x-ray absorption spectroscopy, x-ray fluorescence spectroscopy, and tomography experiments. This enables real-time optimization of material properties and performance for various applications, such as energy transfer, energy storage, catalysis, and corrosion resistance. This paper gives an overview of the analytical methods and sample environments of the BAMline, which cover non-destructive testing experiments in materials science, chemistry, biology, medicine, and cultural heritage. We also present our own synthesis methods, processes, and equipment developed specifically for the BAMline, and we give examples of synthesized materials and their potential applications. Finally, this article discusses the future perspectives of the BAMline and its potential for further advances in sustainable materials research. KW - Extended X-ray absorption fine structure KW - Energy storage KW - Environmental impacts KW - Nondestructive testing techniques KW - X-ray fluorescence spectroscopy KW - Corrosion KW - Near edge X-ray absorption fine structure spectroscopy KW - X-ray absorption spectroscopy PY - 2023 DO - https://doi.org/10.1063/5.0157194 VL - 158 IS - 24 SP - 1 EP - 22 PB - AIP Publishing AN - OPUS4-57824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - ChatGPT and epics: LLM enhanced control systems for synchrotron Beamlines N2 - The presentation describes how large language models (LLMs) such as ChatGPT can be integrated with the EPICS control system to improve the automation and usability of synchrotron beamlines like the BAMline at BESSY II. It explains how LLMs can interpret natural language instructions, translate them into EPICS commands, and interact with experimental tools to perform complex tasks such as moving motors, running scans, or adjusting beamline components. The system, named P.E.T.E.R. (Performance Enhancing Technology for Experimental Research), supports features like multi-step reasoning, Python scripting, feedback loops, multilingual input, and voice control using OpenAI’s ChatGPT and Whisper. T2 - Workshop "BAM - Fraunhofer Materials LLM days" CY - Tübingen, Germany DA - 03.07.2025 KW - Chatgpt KW - LLM KW - EPICS KW - BAMline KW - Sanchrotron PY - 2025 AN - OPUS4-64478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana T1 - Bridging Structure and Electronic State: Real-time XES–XRD Fusion for Functional Alloys N2 - We present a unified X-ray Emission Spectroscopy (XES) and X-ray Diffraction (XRD) approach for real-time, in situ characterization of materials, demonstrated on Co₂FeSi Heusler alloys under varied heat treatments. The combination of XES and XRD is particularly well-suited to Heusler alloys, where subtle changes in atomic ordering and electronic structure (e.g. site occupancy, hybridization, and spin state) are tightly interdependent and critical for their magnetic and transport properties. In addition, this method enables more efficient materials design by reducing experimental iterations through comprehensive structural and electronic analysis. Developed at the mySpot beamline at BESSY-II, the platform integrates (a) digital twin-based experiment planning, (b) open-source XES spectral simulations, (c) an optimized single-shot, two-element XES setup with sub-pixel resolution for enhanced energy precision, and (d) result-driven beamtime utilization. With an unprecedented synchronized XES-XRD platform, we aim to shed light on how diffusion-controlled processes in Heusler alloys and double perovskites at elevated temperatures establish the formation of specific phases with distinct structure types in real time. This, in turn, strongly impacts the functional properties of the materials under scrutiny. T2 - XLIV Colloquium Spectroscopicum Internationale CY - Ulm, Germany DA - 27.07.2025 KW - Multimodal KW - X-ray spectroscopy KW - X-ray diffraction KW - Functional alloys PY - 2025 AN - OPUS4-63991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Machine learning: examples from BAMline N2 - Various applications for artificial intelligence in the context of spectroscopy will be presented. in particular, examples from BAMline will be presented. After a short introduction to synchrotron radiation, artificial intelligence algorithms for the quantification of X-ray fluorescence measurement are discussed. In the second example, information retrieval by natural language processing is discussed. T2 - Analytical Academy CY - Online meeting DA - 02.06.2020 KW - Machine learning KW - BAMline KW - XRF KW - Synchrotron PY - 2020 AN - OPUS4-51898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -