TY - THES A1 - Kazlagić, Anera T1 - Provenancing of cement by the means of isotope techniques N2 - Concrete is the most important human-made material because it serves as the basis of our built environment. Since the properties of concretes are dominated by their key compound, cement, devising a way to determine the cement’s origin, known as provenancing, is of great importance for answering different provenance-related questions. These questions range from liability issues when damage occurs to concrete-made structures, to forensic investigations where cement particles are found at crime scenes. This thesis showcases the use of isotope techniques to answer these provenance-related questions. Conventional 87Sr/86Sr and 143Nd/144Nd isotope and elemental ratios consisting of Ca, Sr, K, Mn, Mg, and Ti are used as fingerprints for ordinary Portland cement (OPC) provenancing. The first part of this thesis describes research previously conducted in fingerprinting cementitious materials, providing an overview of provenance studies of cement and the main approaches commonly used. In several studies, the origin of clinker for certain locations was determined via different approaches. However, clinker is an intermediate product, which is available only at the production site and therefore, the practical relevance is rather limited. Furthermore, the use of Sr and Nd isotope systems, together with elemental fingerprints are presented as state of the art in the field. Therein, the principal approach for the overall study is sketched. For the second part of the study, a sample preparation technique for Sr isotopes in Portland cement was developed. The aim was to find the most appropriate sample preparation procedure for cement provenancing and selection was realised by comparing the 87Sr/86Sr isotope ratios of differently treated OPCs with those of the corresponding clinkers. Based on these findings, the third part of the study focused on the measurements of Sr and Nd isotope ratios, together with elemental ratios, to establish a reliable technique for OPC provenancing. The outcomes of this final stage are then used to establish a procedure for fingerprinting cements. This becomes possible with the use of Sr and Nd isotope ratios and geochemical profiles. To perform isotope ratio measurements and obtain reliable data, it was necessary to establish a quality control procedure. Thus, an interlaboratory comparison (ILC) was organised to characterise 87Sr/86Sr isotope ratios in geological and industrial reference materials by applying the conventional method for 87Sr/86Sr isotope ratios. As reference material, four cements (VDZ 100a, VDZ 200a, VDZ 300a, IAG OPC-1), one limestone (IAG/CGL ML-3) and one slate (IAG OU-6) were selected, thus covering a wide range of Sr isotope signatures. KW - Isotope ratio KW - Strontium KW - Neodymium KW - Ordinary Portland cement PY - 2023 SP - 1 EP - 148 CY - Berlin AN - OPUS4-59172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Understanding mechanochemical reactions: Real-time insights and collaborative research N2 - Mechanochemistry emerges as a potent, environmentally friendly, and straightforward approach for crafting novel multicomponent crystal systems. Various milling parameters, including milling frequency, time, filling degree of the milling jar, ball diameter, vessel size, degree of milling ball filling, and material of jars, are recognized influencers on the mechanisms and rates of product formation. Despite the growing interest in mechanochemistry, there exists a gap in understanding the mechanistic aspects of mechanochemical reactivity and selectivity. To address this, diverse analytical methods and their combinations, such as powder X-ray diffraction, X-ray absorption spectroscopy, NMR, Raman spectroscopy, and thermography, have been developed for real-time, in situ monitoring of mechanochemical transformations. This discussion centers on our recent findings, specifically investigating the formation of (polymorphic) cocrystals and metal-organic frameworks. Through these studies, we aim to unravel the impact of milling parameters and reaction sequences on the formation mechanism and kinetics. Notably, in the mechanochemical chlorination reaction of hydantoin, normalizing kinetic profiles to the volume of the milling ball unequivocally demonstrates the conservation of milling reaction kinetics. In this ball-milling transformation, physical kinetics outweigh chemical factors in determining reaction rates. Attempting to interpret such kinetics solely through chemical terms poses a risk of misinterpretation. Our results highlight that time-resolved in situ investigations of milling reactions provide a novel avenue for fine-tuning and optimizing mechanochemical processes. T2 - PhD Seminar CY - Online meeting DA - 12.10.2023 KW - Mechanochemistry KW - In situ PY - 2023 AN - OPUS4-59022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Investigating the mechanism and kinetics of the mechanochemical synthesis of multi-component systems N2 - Mechanochemistry is a promising and environmentally friendly approach for synthesizing (novel) multicomponent crystal systems. Various milling parameters, such as milling frequency, milling time, and ball diameter have been shown to influence the mechanisms and rates of product formation. Despite increasing interest in mechanochemistry, there is still limited understanding of the underlying reactivity and selectivity mechanisms. Various analytical techniques have been developed to gain insight into the mechanochemical transformations, including powder X-ray diffraction, X-ray adsorption spectroscopy, NMR, Raman spectroscopy and thermography. Using these techniques, we have studied the formation of (polymorphic) cocrystals, organometallic compounds and salts, and elucidated the influence of milling parameters and reaction sequences on the formation mechanism and kinetics. For example, our study of the mechanochemical chlorination reaction of hydantoin revealed that normalisation of the kinetic profiles to the volume of the grinding ball clearly showed that physical kinetics dominate the reaction rates in a ball-milling transformation. Attempts to interpret such kinetics in purely chemical terms risk misinterpretation of the results. Our results suggest that time-resolved in situ investigation of milling reactions is a promising way to fine-tune and optimise mechanochemical processes. T2 - ISIC 2023 CY - Glasgow, Scotland DA - 05.09.2023 KW - Mechanochemistry KW - Polymorphy KW - In situ PY - 2023 AN - OPUS4-59023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Combination of complementary methods For in situ studies N2 - This talk explores the synergistic application of complementary synchrotron methods for in situ investigations, providing a comprehensive approach to enhance analytical capabilities in materials research and characterization. T2 - INSYNX - DEUTSCH-BRASILIANISCHER WORKSHOP ON BREAKING BOUNDARIES OF IN SITU SYNCHROTRON X-RAY METHODS CY - Sao Paulo, Brazil DA - 06.03.2023 KW - In situ KW - Synchrotron PY - 2023 AN - OPUS4-59025 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Understanding mechanochemical reactions: Real-time insights and collaborative research N2 - Mechanochemistry emerges as a potent, environmentally friendly, and straightforward approach for crafting novel multicomponent crystal systems. Various milling parameters, including milling frequency, time, filling degree of the milling jar, ball diameter, vessel size, degree of milling ball filling, and material of jars, are recognized influencers on the mechanisms and rates of product formation. Despite the growing interest in mechanochemistry, there exists a gap in understanding the mechanistic aspects of mechanochemical reactivity and selectivity. To address this, diverse analytical methods and their combinations, such as powder X-ray diffraction, X-ray absorption spectroscopy, NMR, Raman spectroscopy, and thermography, have been developed for real-time, in situ monitoring of mechanochemical transformations. This discussion centers on our recent findings, specifically investigating the formation of (polymorphic) cocrystals and metal-organic frameworks. Through these studies, we aim to unravel the impact of milling parameters and reaction sequences on the formation mechanism and kinetics. Notably, in the mechanochemical chlorination reaction of hydantoin, normalizing kinetic profiles to the volume of the milling ball unequivocally demonstrates the conservation of milling reaction kinetics. In this ball-milling transformation, physical kinetics outweigh chemical factors in determining reaction rates. Attempting to interpret such kinetics solely through chemical terms poses a risk of misinterpretation. Our results highlight that time-resolved in situ investigations of milling reactions provide a novel avenue for fine-tuning and optimizing mechanochemical processes. T2 - Brimingham Green chemistry CY - Birmingham, England DA - 08.09.2023 KW - Mechanochemistry KW - Green Chemistry PY - 2023 AN - OPUS4-59024 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Understanding mechanochemical reactions: Real-time insights and collaborative research N2 - Mechanochemistry has become a compelling method for producing (new) molecule s and mate-rials, but the inner workings of the milling jars remain a fascinating mystery. Advances in this field include tailor-made chemical systems and real-time revelations using techniques such as XRD and Raman spectroscopy. This talk will discuss our recent progress in using X-ray diffraction and sophisticated spectros-copy to observe reactions in various material systems during ball milling and extrusion in real-time. The complexity of mechanochemical reactions spans multiple scales and requires a holistic ap-proach. The categorisation of reactions by investigative methods precedes the exploration of real-time analysis that reveals macroscopic processes using synchrotron techniques. During this exploration, one resounding realisation remains: We are on the threshold of under-standing. The complexity of mechanochemistry requires a collective effort, drawing on the ex-pertise of a diverse community. As we unravel the web of mechanochemical phenomena, we acknowledge the collaborative nature of this ongoing journey. T2 - CMCC Mechanochemistry Discussions CY - Online meeting DA - 21.09.2023 KW - Mechanochemistry KW - In situ PY - 2023 AN - OPUS4-59026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ciornii, Dmitri T1 - Getting reliable data on microplastic detection methods by means of ILC N2 - There is an urgent demand for reliable data on microplastic analysis, particularly on its physico-chemical properties as well as validated methodology to obtain such data. Through interlaboratory comparisons (ILCs) it becomes possible to assess accuracy and precision of methods by involving many laboratories around the world. At BAM, my tasks focused around organisation of an ILC on physico-chemical characterisation of microplastic detection methods under the international pre-standardisation platform VAMAS (www.vamas.org/twa45/) as Project 2 “Development of standardized methodologies for characterisation of microplastics with microscopy and spectroscopy methods” under the Technical Working Area TWA 45 “Micro and Nano Plastics in the Environment”. With a proud number of 84 participants this ILC is able to provide superior statistical results. Thermoanalytical (Py-GC/MS and TED-GC/MS) and vibrational (µ-IR and µ-Raman) methods were asked for identification and quantification of microplastic test samples according to mass or particle number. Preliminary results indicate which methods show a higher accuracy and precision and reveal some sample preparation ideas which work best for microplastics characterisation. At the end of the ILC an overall plausibility of the results will be assessed. T2 - CUSP Early Career Researchers Meeting CY - Online meeting DA - 21.11.2023 KW - Micro- and Nanoplastics KW - Interlaboratory comparison KW - Microplastic reference materials PY - 2023 AN - OPUS4-59056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Connecting the nodes: networks and networking N2 - This talk explores the intricate connections between scientists, focusing on the networking dynamics within the realm of metal-organic frameworks (MOFs). The study delves into the collaborative networks formed among scientists, shedding light on the synergistic relationships that contribute to advancements in MOF research. T2 - WINS School 2023 Frameworks and networks CY - Blossin, Germany DA - 02.06.2023 KW - Metal-organic frameworks PY - 2023 AN - OPUS4-59028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Casali, Lucia T1 - Use of the solvent-free mechanochemical method for a sustainable preparation of pharmaceuticals N2 - With the growing interest in environmental issues on the part of governments and institutions, pharmaceutical industries are asked to reduce their environmental footprint. Given the major impact related to the use of solvents, the development of methodologies less solvent demanding is nowadays even more urgent. In light of that, mechanochemistry would be a suitable solvent-free technology since it promotes the activation of the chemical reactions between (generally) solid materials via inputs of mechanical energy. Since such reactions may occur outside the kinetic and thermodynamic rules of conventional solution chemistry, the main limit of mechanochemistry is the poor mechanistic understanding of the solid-state transformations involved, which is still hindering a widespread use of the method, as well a scale-up to the industrial level. However, the development of methods for real-time monitoring of the mechanochemical reactions enables obtaining (in)accessible information on reaction intermediates, new products, or reaction time, thus getting closer to a better understanding of the mechanistic behaviour. With the rules of this chemistry becoming increasingly clear, the new reaction pathways of mechanochemistry wouldn’t represent a limit anymore, but an asset, that may lead to lot of opportunities for the pharmaceutical industry. T2 - Post Doc Day Berlin CY - Berlin, Germany DA - 02.11.2023 KW - Mechanochemistry KW - Sustainability KW - Pharmaceuticals PY - 2023 AN - OPUS4-59010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. T1 - Simulationsdaten zur photooxidativen Beanspruchung an verschiedenen geografischen Freibewitterungs-Standorten N2 - Freibewitterungen weisen grundsätzlich eine hohe Variabilität der jeweiligen Intensität der Beanspruchungsparameter auf; sie sind nicht einfach wiederholbar. Um dennoch die Ergebnisse einer Beanspruchung vergleichen zu können, ist eine aussagekräftige Charakterisierung der Freibewitterung wichtig. Traditionell werden Daten bekannter Einflussgrößen wie Globalstrahlung, Temperatur oder Feuchtewerte herangezogen. Obwohl man weiß, dass diese Größen an den exponierten Oberflächen wechselwirken und kombiniert als Mikroklima Einfluss auf Degradationsprozesse nehmen, werden schon aus Praktikabilitätsgründen diese separat als klimatische Messgrößen angegeben. Die Aussagekraft dieser Daten ist mäßig. Ziel dieses Beitrags ist es, die Aussagekraft und damit Vergleichbarkeit zu erhöhen, indem diese Messdaten als Stundendaten zu Wirkintegralen vorverarbeitet und jahresweise akkumuliert werden. Betrachtet wird dafür der Prozess der Photooxidation, da dieser Alterungs-mechanismus bei allen Kunststoffen auftritt. Für eine einfache Modellierung wird die wirksame UV-Bestrahlung, gewichtet mit einer Arrhenius-abhängigen Ober¬flächen-temperatur (TOF), über den Beanspruchungszeitraum von hier je einem Jahr akkumuliert. Die Idee einer solchen Messgröße für photooxidative Ober¬flächen¬alterung wurde bereits vorgestellt [1]. Dort wurde ein Gerät vor¬geschlagen, mit dem dieser Wert für verschieden absorbierende Oberflächen für die Dauer einer Exposition akkumuliert wird, und ergänzend eine Abschätzung der Betauungs¬zeiten dieser Referenz-Oberflächen erfolgen könnte. Hier soll es um eine rechnerisch generierte Zusammenstellung dieser photo¬oxidativen 1-Jahres-Alterungswerte für verschiedene Standorte gehen. Ein Temperaturfaktor erfasst dabei den Einfluss der Strahlungserwärmung auf eine weiße, graue bzw. schwarze Referenzoberflächen, spiegelt also die Kopplung von solarer Strahlung und Temperatur wider [1]. Ermittelt wird er aus Stunden¬daten der Globalstrahlung und der Lufttemperatur. Die spektrale Wirkung wird aus Sonnenhöhenständen entsprechend der geografischen Breite mit Hilfe der FastRT-Oberfläche [2] als PiT·h-Wert abgeschätzt [3]. Anhand der errechneten Jahreswerte können die Schweregrade der photo¬oxidativen Beanspruchung an den verschiedenen Standorten unmittelbar verglichen werden. Die gezeigten Simulationsdaten für ein solches „elektronisches Referenzmaterial“ für photooxidative Degradation zeigen die prinzipielle Möglichkeit einer Kartografierung solcher Daten auf. T2 - 53. Jahrestagung der GUS CY - Stutensee-Blankenloch, Germany DA - 26.03.2025 KW - Polymer 3R, UV, Bestrahlung, Bewitterung PY - 2025 SN - 978-3-9826129-2-8 VL - 53 SP - 19 EP - 28 PB - Gesellschaft für Umweltsimulation e.V. CY - 76327 Pfinztal (Berghausen) AN - OPUS4-62902 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Trubiroha, Peter A1 - Wachtendorf, Volker T1 - Significance of new data pairs for irradiance and (surface) temperature N2 - There is consent that UV irradiance and temperature at the place of photodegradation are the most important environmental parameters in weathering, along with humidity. This contribution shows how an improvement in the measurement data situation can improve the significance and comparability of outdoor exposures. Photooxidative ageing is calculated using sample polymers for which the corresponding modelling data (Exposure Response Functions, ERF) is available. The mean square deviations are estimated, which result from using different spectral irradiances and different spectral sensitivities, both of the sensors and the polymers. It will be shown here how the significance of the irradiance values increases with increasing approximation of the spectral sensitivities of the sensor and polymer. Also, the mean square deviations are estimated, which result from using different activation energies and surface temperatures. A selection of different variables to describe the weathering exposure is created. The potential of either individual values or data pairs is evaluated in terms of significance or correlation to the calculated photooxidative ageing. Recording hourly data also enables subsequent evaluations of individual test specimens, adapted to the respective colour or to determine activation energies. An accumulated value, calculated from PIT-radiometer irradiance and a suited surface temperature, can provide a comparison of different outdoor exposures over different locations or years. Thus, a characterisation of the weathering exposure would be related to a reference spectral sensitivity (much closer to a polymer than that of a common UV radiometer), one reference activation energy, and different surface temperature scenarios with, on the one hand, graded solar absorptions (white / grey / black) and, on the other hand, different thermal couplings (coated metal / thick plastic). This results in three values each for plastic samples and coated metals (light / grey / dark). It will never be possible to accurately predict the weathering tests for individual samples (with their specific sensitivities), but the proposed approaches can go a long way towards the comparability of outdoor weathering exposures. T2 - 10th European Weathering Symposium EWS CY - Graz, Austria DA - 11.09.2024 KW - Polymer 3R KW - Outdoor weathering PY - 2024 SN - 978-3-9826129-1-1 SP - 121 EP - 133 PB - Stober Medien GmbH CY - Eggenstein AN - OPUS4-61291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Significance of new data pairs for irradiance and (surface) temperature N2 - There is consent that UV irradiance and temperature at the place of photodegradation are the most important environmental parameters in weathering, along with humidity. This contribution shows how an improvement in the measurement data situation can improve the significance and comparability of outdoor exposures. Photooxidative ageing is calculated using sample polymers for which the corresponding modelling data (Exposure Response Functions, ERF) is available. The mean square deviations are estimated, which result from using different spectral irradiances and different spectral sensitivities, both of the sensors and the polymers. It will be shown here how the significance of the irradiance values increases with increasing approximation of the spectral sensitivities of the sensor and polymer. Also, the mean square deviations are estimated, which result from using different activation energies and surface temperatures. A selection of different variables to describe the weathering exposure is created. The potential of either individual values or data pairs is evaluated in terms of significance or correlation to the calculated photooxidative ageing. Recording hourly data also enables subsequent evaluations of individual test specimens, adapted to the respective colour or to determine activation energies. An accumulated value, calculated from PIT-radiometer irradiance and a suited surface temperature, can provide a comparison of different outdoor exposures over different locations or years. Thus, a characterisation of the weathering exposure would be related to a reference spectral sensitivity (much closer to a polymer than that of a common UV radiometer), one reference activation energy, and different surface temperature scenarios with, on the one hand, graded solar absorptions (white / grey / black) and, on the other hand, different thermal couplings (coated metal / thick plastic). This results in three values each for plastic samples and coated metals (light / grey / dark). It will never be possible to accurately predict the weathering tests for individual samples (with their specific sensitivities), but the proposed approaches can go a long way towards the comparability of outdoor weathering exposures. T2 - 10th European Weathering Symposium EWS CY - Graz, Austria DA - 11.09.2024 KW - Polymer 3R KW - Outdoor weathering PY - 2024 AN - OPUS4-61292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - McSAS3: live demo of a Monte Carlo data analyis package for scattering studies N2 - McSAS3 is a refactored software package for fitting large batches of (X-ray or Neutron) scattering data. It uses a Monte-Carlo acceptance-rejection algorithm to optimize model parameters - ideal for analysis of size-disperse scatterers. The refactored code can exploit multiprocessing, traceably stores (multiple) results in the output file, and allows for re-histogramming of previous optimizations. Besides analysis of large batches, it can also be integrated in automated data processing pipelines. The live demonstration will show how to use the software, what its limitations are, and what outcomes can look like for batches of results. T2 - SAS Analysis Course 2023 CY - Didcot, UK DA - 05.06.2023 KW - Scattering KW - Software KW - Analysis KW - Demonstration KW - McSAS3 KW - MOUSE KW - Monte Carlo KW - Automated analysis PY - 2023 AN - OPUS4-57630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. T1 - Discussion on Weathering Reference Materials N2 - Weathering reference materials (WRMs) are used to characterize the harshness of an exposure, aiming on either reproducibility of a specific exposure or on the comparability between various kinds of natural or artificial weathering exposure. The materials that are used as weathering reference materials differ in their sensitivities (as well as in interactions and interferences of the latter), conditioned by the different processes which lead to the respective property change. It is also essential to take into account the necessary measurement equipment for the respective property change, in order to allow timely intervention. What are the key issues on choosing a weathering reference material? What can be learned from the weathering reference materials, investigated so far? Possibilities and limitations are discussed on the basis of existing weathering reference materials. Conclusions are drawn, for establishing new weathering reference materials. T2 - 9th European Weathering Symposium CY - Basel, Switzerland DA - 18.09.2019 KW - Temperature dependency KW - Weathering KW - Irradiation KW - Spectral sensitivity PY - 2019 SN - 978-3-9818507-5-8 SP - 283 EP - 292 PB - Thomas Würtz Grafik-Design CY - Karlsruhe, Germany AN - OPUS4-49150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kohlbrecher, J. A1 - Breßler, Ingo T1 - SASfit 0.94.12 N2 - Small-angle scattering is an increasingly common method for characterizing particle ensembles in a wide variety of sample types and for diverse areas of application. SASfit has been one of the most comprehensive and flexible curve-fitting programs for decades, with many specialized tools for various fields. KW - Small-angle scattering KW - SAXS KW - SANS KW - Scattering pattern analysis PY - 2023 UR - https://doi.org/10.5281/zenodo.7530357 DO - https://doi.org/10.5281/zenodo.7530356 PB - Zenodo CY - Geneva AN - OPUS4-57913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. A1 - Giehl, A. A1 - Schönlein, A. A1 - Feil, F. T1 - Normenvorschlag zur Bewitterung transparenter oder transluzenter Kunststoffe N2 - Aufgrund des tieferen Eindringens der solaren Strahlung treten bei transparenten und bei transluzenten (durchscheinenden) Kunststoffen veränderte Bedingungen gegenüber opaken Proben auf. Dies kann zu speziellen Effekten und damit zu einem abweichenden Bewitterungsverhalten führen. Auch aus Mangel an geeigneten Normen werden diese Effekte häufig vernachlässigt. Deshalb initiiert der DIN-FNK auf ISO-Ebene ein entsprechendes Dokument. Die Norm ist in der Form eines Technical Reports geplant. In einem ersten Teil sollen die Besonderheiten transparenter oder transluzenter Kunststoffe erläutert werden, um den Nutzer für mögliche Probleme zu sensibilisieren. Im zweiten Teil werden Empfehlungen für Bestrahlung oder Bewitterung herausgearbeitet. In einem dritten Teil geht es dann um Besonderheiten bei der Messung von Eigenschaftsänderungen transparenter bzw. transluzenter Kunststoffe. In informativen Anhängen sollen verschiedene Beispiele die Thematik illustrieren. T2 - 51. Jahrestagung der GUS CY - Stutensee-Blankenloch, Germany DA - 29.03.2023 KW - Bewitterung KW - Polymer 3R KW - Bestrahlung KW - UV PY - 2023 SN - 978-3-9818507-8-9 SP - 39 EP - 46 PB - Gesellschaft für Umweltsimulation e.V. CY - Pfinztal (Berghausen) AN - OPUS4-57271 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Simulationsdaten zur photooxidativen Beanspruchung an verschiedenen geografischen Freibewitterungs-Standorten N2 - Freibewitterungen weisen grundsätzlich eine hohe Variabilität der jeweiligen Intensität der Beanspruchungsparameter auf; sie sind nicht einfach wiederholbar. Um dennoch die Ergebnisse einer Beanspruchung vergleichen zu können, ist eine aussagekräftige Charakterisierung der Freibewitterung wichtig. Traditionell werden Daten bekannter Einflussgrößen wie Globalstrahlung, Temperatur oder Feuchtewerte herangezogen. Obwohl man weiß, dass diese Größen an den exponierten Oberflächen wechselwirken und kombiniert als Mikroklima Einfluss auf Degradationsprozesse nehmen, werden schon aus Praktikabilitätsgründen diese separat als klimatische Messgrößen angegeben. Die Aussagekraft dieser Daten ist mäßig. Ziel dieses Beitrags ist es, die Aussagekraft und damit Vergleichbarkeit zu erhöhen, indem diese Messdaten als Stundendaten zu Wirkintegralen vorverarbeitet und jahresweise akkumuliert werden. Betrachtet wird dafür der Prozess der Photooxidation, da dieser Alterungs-mechanismus bei allen Kunststoffen auftritt. Für eine einfache Modellierung wird die wirksame UV-Bestrahlung, gewichtet mit einer Arrhenius-abhängigen Ober¬flächen-temperatur (TOF), über den Beanspruchungszeitraum von hier je einem Jahr akkumuliert. Die Idee einer solchen Messgröße für photooxidative Ober¬flächen¬alterung wurde bereits vorgestellt [1]. Dort wurde ein Gerät vor¬geschlagen, mit dem dieser Wert für verschieden absorbierende Oberflächen für die Dauer einer Exposition akkumuliert wird, und ergänzend eine Abschätzung der Betauungs¬zeiten dieser Referenz-Oberflächen erfolgen könnte. Hier soll es um eine rechnerisch generierte Zusammenstellung dieser photo¬oxidativen 1-Jahres-Alterungswerte für verschiedene Standorte gehen. Ein Temperaturfaktor erfasst dabei den Einfluss der Strahlungserwärmung auf eine weiße, graue bzw. schwarze Referenzoberflächen, spiegelt also die Kopplung von solarer Strahlung und Temperatur wider [1]. Ermittelt wird er aus Stunden¬daten der Globalstrahlung und der Lufttemperatur. Die spektrale Wirkung wird aus Sonnenhöhenständen entsprechend der geografischen Breite mit Hilfe der FastRT-Oberfläche [2] als PiT·h-Wert abgeschätzt [3]. Anhand der errechneten Jahreswerte können die Schweregrade der photo¬oxidativen Beanspruchung an den verschiedenen Standorten unmittelbar verglichen werden. Die gezeigten Simulationsdaten für ein solches „elektronisches Referenzmaterial“ für photooxidative Degradation zeigen die prinzipielle Möglichkeit einer Kartografierung solcher Daten auf. T2 - 53. Jahrestagung der GUS CY - Stutensee, Germany DA - 26.3.2025 KW - Polymer 3R KW - UV KW - Bestrahlung KW - Bewitterung PY - 2025 AN - OPUS4-62903 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Digitale Umweltsimulation am Beispiel der Photooxidation von Polymeren N2 - Die Umweltwirkungen auf ein Material werden als Überlapp der Funktionskurven von Materialempfindlichkeit und einwirkenden Umweltparametern betrachtet. Wenn entweder die Empfindlichkeit oder die Beanspruchungen Null sind, ergibt sich auch keine Umweltwirkung und bei beidseitig Werten größer Null das jeweilige Produkt der beiden. Die Akkumulation der nicht-reversiblen Effekte über die Zeit und allen Eigenschaftsänderungen entspricht der Alterung des Materials für den jeweiligen Expositionszeitraum. Die digitale Umweltsimulation gliedert sich hier in drei Teilaspekte. Ein erster, rein materialwissenschaftlicher Teil hat die Aufgabe, alle relevanten Materialempfindlichkeiten experimentell zu quantifizieren. Ein zweiter – unter Umständen numerischer Teil – hat die Aufgabe, das Bauteil und seine Einbaulage zu digitalisieren und aus den makroskopischen Umgebungsbedingungen die relevanten mikroklimatischen Umweltparameter für alle Oberflächen- oder Volumenelemente zu bestimmen. In einem dritten Teil werden die Einwirkungen über den betrachteten Zeitraum berechnet und kumuliert. Dieses Konzept, das auf den so genannten Expositions-Reaktions-Funktionen (ERF) basiert, wird an Beispielen der Photoxidation erläutert. Dieses Vorgehen wurde schon beim ViPQuali-Projekt als Numerische Umweltsimulation umgesetzt. Überprüft werden muss das Modell unbedingt an einer realitätsnahen Validierungsbeanspruchung. Hier werden die ermittelten ERFs mit über den kompletten Beanspruchungszeitraum geloggten Umweltparametern gekoppelt, um die berechnete mit der experimentell erfahrenen Alterungswirkung zu vergleichen. Nur so kann sichergestellt sein, dass alle für die Anwendungsumgebung relevanten Materialempfindlichkeiten einbezogen wurden. T2 - 52. Jahrestagung der GUS CY - Blankenloch, Germany DA - 26.03.2024 KW - Polymer 3R KW - UV KW - Bestrahlung KW - Bewitterung PY - 2024 AN - OPUS4-59831 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker T1 - Gedanken, Tipps & Tricks zu künstlichen Bewitterungsprüfungen N2 - Die Fragestellung kann nur exemplarisch dargestellt werden, aber ist hoffentlich auch für langjährige Praktiker in den ausgewählten Punkten interessant. Es sollen für folgende Bereiche Beispiele gegeben werden: Probenvorbereitung, Testvorbereitung, Testdurchführung und Auswertung. T2 - 53. Jahrestagung der GUS 2025; Umwelteinflüsse erfassen, simulieren, bewerten. CY - Stutensee, Germany DA - 26.03.2025 KW - Künstliche Bewitterung KW - Umweltsimulation KW - Wechseltemperaturen KW - Prüfung KW - UV KW - Feuchte KW - Beregnung PY - 2025 AN - OPUS4-62862 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Possibilities on prediction of plastic’s fragmentation time - Digital twins for decomposing-time predictions N2 - Depending on the specific plastic’s ageing sensitivities, the durations which plastic components remain in the environment can be very long. As, in the past, the advantages in ageing resistance and durability were highly evaluated, we now face the problem of quite stable plastic waste within the environment. However, there is only little knowledge on the real timescales until macroscopic fragmentation for the different kinds of plastic under various environmental conditions. Here, weathering methods are presented, which have been used for the failure prediction in specific outdoor conditions. Issues of uncertainty, reproducibility, or validation are discussed. For the prediction of the plastic’s fragmentation, much longer time scales have to be considered. To do this within a limited project life span, various processes as well as their acceleration potential have to be evaluated separately, such as temperature increase or spectral shift. The possibilities and limitations of such controlled acceleration will be discussed. T2 - 29th IAPRI Symposium on Packaging CY - Twente, Enschede, The Netherlands DA - 11.06.2019 KW - Plastic KW - Ageing KW - Environment KW - Fragmentation KW - Digital twin PY - 2019 AN - OPUS4-49714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja 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 - UV exposure KW - Nitric acid KW - Polyethylene KW - Oxidation PY - 2024 AN - OPUS4-60416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachtendorf, Volker A1 - Schulz, Ulrich A1 - Geburtig, Anja A1 - Stephan, Ina T1 - Mildew growth on automotive coatings influencing the results of outdoor weathering N2 - As the results of a 14 weeks outdoor exposure of a series of automotive coatings in South Florida, the panels were found to be overgrown with an almost closed layer of mildew. Pinholes remained as permanent surface damage after removing the mildew mycelium. The extent of the damage differed in dependence of the kind of the coating. By tracing the images and profiles of the coating surfaces systematically over all phases of weathering and the subsequent cleaning procedure, a connection between formation of pinholes and mildew growth could be found. Outdoor weathering tests in other regions of Florida as well as in Europe and Australia showed that pinholes caused by mildew attack could also be found in all other locations, but always to a lower extent than in South Florida. The standardised mildew tests EN ISO 846 and MIL-STD 810F for laboratory exposure failed to reproduce the formation of pinholes. KW - Coatings KW - Mildew KW - Weathering KW - South Florida PY - 2012 DO - https://doi.org/10.1002/maco.201005784 SN - 0947-5117 SN - 1521-4176 VL - 63 IS - 2 SP - 140 EP - 147 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - PE-Rezyklat Einsatz in Gefahrgutbehältern? N2 - In diesem Vortrag geht es darum zu beschreiben, ob Rezyklat für PE Behälter gefüllt mit Gefahrgut Anwendung finden darf. Kanister aus Neuware und Rezyklat wurden verschiedenen Untersuchungen unterzogen. Es wurde der Feststoff und Leachable getestet. Methoden sind TED-GC/MS und GC-HRMS. Proben der Leachable wurden nach 1 und 4 Wochen genommen und die Peakanzahl vergleichen dargestellt. Als Lösemittel wurden Wasser, Ethanol, EtOAc, Ammoniak und HNO3 verwendet. T2 - Fachaustausch Projekt GeSKAR CY - Dessau, Germany DA - 10.01.2025 KW - Gefahrgutbehälter KW - Rezyklat PY - 2025 AN - OPUS4-62396 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - What can thermoanalytical methods do for you ? N2 - This presentation summarizes outcomes of the CUSP projects POLYRISK and PlasticsFatE according to thermoanalytical methods.It highlights the importants of analytical methods to measure physical and chemical properties of the test materials. These informations are neccessary for interpretation of the toxicological test results. T2 - CUSP conference CY - Utrecht, Netherlands DA - 14.09.2023 KW - Microplastics KW - TED-GC/MS KW - CUSP KW - Polymer 3R KW - Thermoanalytical methods PY - 2023 AN - OPUS4-58312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wallstabe, Ronald T1 - Laser-assisted surface modification of alumina and its tribological behavior N2 - High performance friction systems, e.g., dry clutches and brakes, require a good wear resistance and a friction coefficient that is nearly independent from sliding velocity and environmental conditions. Organic-based friction materials have reached their limitations regarding higher power densities. Engineering ceramics such as alumina (Al2O3) or silicon carbide (SiC) offer a great potential since remarkably higher thermal and mechanical loading is possible. However, the tribological performance of these monolithic ceramics is still insufficient. The aim of the present study was to assess the potential of a laser-assisted surface modification process in order to improve the tribological performance with regard to the application in dry friction systems. Therefore, commercially available alumina was modified using a newly developed laser-assisted preheating process and subsequent melting of the ceramic’s surface using a CO2-laser and modification by additives such as TiC, TiN, B4C, WC, ZrB2, Cr, Ni, Cu, and Ti. A systematic variation of additives and process parameters led to different multiphase microstructures. Subsequently, these were characterized using scanning electron microscopy and surface analysis methods (wavelength dispersive X-ray spectroscopy, energy dispersive X-ray spectroscopy). Finally, the tribological properties were investigated using a laboratory tribometer. The surface-modified ceramics were tested in unidirectional sliding motion against steel disks. The tribological results of the surface-modified ceramics were compared to those of monolithic Al2O3 and SiC ceramics and showed a reduced dependence of friction coefficient on sliding velocity. Moreover, the multi-phase ceramics possessed a higher wear resistance than the monolithic ones. KW - Alumina KW - Ceramics KW - Ceramic matrix composites KW - Dry sliding KW - Laser-assisted surface modification KW - Steel KW - Tribology KW - Wear resistance PY - 2013 DO - https://doi.org/10.1007/s11665-012-0215-2 SN - 1059-9495 SN - 1544-1024 VL - 22 IS - 1 SP - 223 EP - 235 PB - ASM International CY - Materials Park, Ohio AN - OPUS4-25842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Wägner, Yannick A1 - Geburtig, Anja T1 - Gedanken, Tipps & Tricks zu künstlichen Bewitterungsprüfungen N2 - Die Fragestellung kann nur exemplarisch dargestellt werden, aber ist hoffentlich auch für langjährige Praktiker in den ausgewählten Punkten interessant. Es sollen für folgende Bereiche Beispiele gegeben werden: Probenvorbereitung, Testvorbereitung, Testdurchführung und Auswertung. T2 - 53. Jahrestagung der GUS 2025 CY - Stutensee-Blankenloch bei Karlsruhe, Germany DA - 26.03.2025 KW - Wechseltemperaturen KW - Künstliche Bewitterung KW - Prüfung KW - UV KW - Feuchte KW - Beregnung PY - 2025 SN - 978-3-9826129-2-8 VL - 53 SP - 253 EP - 257 PB - Gesellschaft für Umweltsimulation e.V. CY - 76327 Pfinztal (Berghausen) AN - OPUS4-62861 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kaltzakorta, O. A1 - Wäsche, Rolf A1 - Hartelt, Manfred A1 - Aginagalde, A. A1 - Tato, W. T1 - Influence of polymer filler on tribological properties of thermoplastic polyurethane under oscillating sliding conditions against cast iron N2 - The tribological behaviour of unfilled thermoplastic polyurethane (TPU) and a polymer sphere filled (TPUG) thermoplastic polyurethane have been studied under oscillating sliding condition against cast iron as a counterpart. In the case of unfilled TPU, the wear mechanisms are dominated by particle detachment and roll formation. In principle, TPUG also showed a similar wear mechanism as that of unfilled TPU; in addition, particle pull-out and delamination are also observed. Wear volume of TPUG was significantly higher than that for the unfilled TPU and this is attributed to the different material removal processes taking place in the material during sliding. The polymer spheres as a filler material deteriorated the wear resistance of TPU because of improper adhesion and bonding of filler in the TPU matrix and therefore it contributed to more wear. In case of TPU the friction behaviour was strongly dependant on the temperature and surface roughness of the counter body. The results showed that below the glass transition temperature higher friction values are observed with higher counter body surface roughness. However, above the glass transition temperature, higher friction values are observed with a smoother surface roughness of the counter body. In case of TPUG, the friction behaviour was not significantly dependent on surface roughness of the counter body. KW - Dry sliding KW - Polymers KW - Cast iron KW - Temperature PY - 2012 DO - https://doi.org/10.1007/s11249-012-0017-6 SN - 1023-8883 SN - 1573-2711 VL - 48 IS - 2 SP - 209 EP - 216 PB - Springer Science Business Media B.V. CY - Dordrecht AN - OPUS4-27272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker T1 - „Test Tailoring“ eines künstlichen Bewitterungstests am Beispiel der Entwicklung des „Acid Dew and Fog“ Testes N2 - Häufig ist es wünschenswert, für neue Materialien oder Anwendungen künstliche Bewitterungsverfahren zu benutzen, die auf die spezifischen Anforderungen besser zugeschnitten sind, als es bei bestehenden standardisierten Verfahren der Fall ist. Nachdem man die spezifischen Parameter der Beanspruchung unter Anwendungsbedingungen und die spezifische Empfindlichkeit des Materials erfasst hat, beginnt ein Prozess, der als „Test Tailoring“ häufig abstrakt verwendet, auf den aber nur selten näher eingegangen wird. Genau dieser Prozess soll hier am Beispiel der Entwicklung eines künstlichen Bewitterungstests unter saurer Beaufschlagung, dem in der BAM entwickelten Acid Dew and Fog Test, beispielhaft erläutert werden. T2 - 47. Jahrestagung der Gesellschaft für Umweltsimulation (GUS) 2018 CY - Pfinztal (Berghausen), Germany DA - 21.03.2018 KW - Test Tailoring KW - Bewitterung KW - Acid Dew and Fog KW - Umweltsimulation PY - 2018 AN - OPUS4-46542 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karrasch, Andrea A1 - Wawrzyn, Eliza A1 - Schartel, Bernhard A1 - Jäger, Christian T1 - Solid-state NMR on thermal and fire residues of bisphenol A polycarbonate/silicone acrylate rubber/bisphenol A bis(diphenyl-phosphate)/(PC(SiR/BDP) and PC/SiR/BDP/zinc borate (PC/SiR/BDP/ZnB) - Part 1: PC charring and the impact of BDP and ZnB N2 - Structural changes in the condensed phase of bisphenol A polycarbonate (containing 0.45 wt% poly (tetrafluoroethylene))/silicone acrylate rubber/bisphenol A bis(diphenyl-phosphate) (PC/SiR/BDP) and PC/SiR/BDP/zinc borate (PC/SiR/BDP/ZnB) during thermal treatment in nitrogen atmosphere and in fire residues were investigated by solid-state NMR. H-1, B-11, C-13 and P-31 NMR experiments using direct excitation with a single pulse and H-1-P-31 cross-polarization (CP) were carried out including 31P(1 H) and C-13{P-31}double-resonance techniques (REDOR: Rotational Echo Double Resonance) on a series of heat-treated samples (580 K-850 K). Because many amorphous phases occur in the solid residues, and solid-state NMR spectroscopy addresses the most important sites carbon, phosphorus and boron, this paper is the key analytical approach for understanding the pyrolysis and flame retarding phenomenon in the condensed phase of PC/SiR/BDP and PC/SiR/BDP/ZnB. For the system PC/SiR/BDP it is shown that (i) at temperatures around 750-770 K (main decomposition step) carbonaceous charring of PC occurs and arylphosphate structures are still present, reacted in part with the decomposing PC; (ii) for higher temperatures from 770 K the phosphorus remaining in the solid phase increasingly converts to amorphous phosphonates and inorganic orthophosphates with a minor amount of crystalline orthophosphates; and (iii) H-1-P-31{H-1} CP REDOR and H-1-C-13{P-31} CP REDOR NMR experiments suggest that the phosphates and phosphonates are bound via oxygen to aromatic carbons, indicating the interaction with the carbonaceous char. When ZnB is added to the system PC/SiR/BDP, (i) ZnB leads to a slightly enhanced PC decomposition for temperatures below 750 K; (ii) alpha-Zn-3(PO4)(2) and borophosphate (BPO4) are formed in small amounts at high temperatures suggesting a reaction between BDP and ZnB during thermal decomposition; and (iii) most of the borate remains in the solid residues, forming an amorphous pure borate network, with the BO3/BO4 ratio increasing with higher temperatures. The NMR data of thermal and fire residues are highly correlated, underlining the importance of this work for understanding the pyrolysis and flame retardancy mechanisms in the condensed phase during the burning of the PC/SiR blends. (C) 2010 Elsevier Ltd. All rights reserved. KW - Flame retardance KW - NMR KW - Polycarbonate (PC) blends KW - Bisphenol-A bis(diphenyl)phosphate (BDP) KW - Zinc borate PY - 2010 DO - https://doi.org/10.1016/j.polymdegradstab.2010.07.034 SN - 0141-3910 SN - 1873-2321 VL - 95 IS - 12 SP - 2525 EP - 2533 PB - Applied Science Publ. CY - London AN - OPUS4-22647 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Schmidt, Anita A1 - Goedecke, Thomas T1 - Combined impact of UV radiation and nitric acid on HDPE containers during outdoor exposure T1 - Kombinierte Einwirkung von UV-Strahlung und Salpetersäure auf HDPE-Behälter bei der Freibewitterung N2 - Unpigmented HDPE jerrycans filled with nitric acid (55%) and water respectively had been exposed to outdoor conditions for one Berlin summer season. As both liquids underwent equal temperature progression, exposure effects of UV radiation and nitric acid as well as of their combination can be separated and compared. On the basis of various property changes after these exposures, synergistic action is evaluated and compared to a damaged Intermediate Bulk Container (IBC) from a transport accident. It is found that carbonyl formation goes along with lightness increase in color measurement due to microcracking and with a worsening in mechanical behavior, all of them showing synergistic effects of UV and nitric acid exposure. In contrast, embedding nitrogen compounds goes along with yellowing of the material but cannot be correlated to oxidation. The reason for intensified damaging is the decomposition of the 55-percent nitric acid and formation of nitrogen oxides even at ambient temperatures, caused by UV radiation. Thus, damaging effects become similar to those caused by fuming nitric acid exposure at temperatures above 60 °C, with the result of strong oxidative degradation of the polyethylene. In contrast, exclusive exposure to the 55-percent nitric acid at 40 °C does not cause any failure. It can therefore be assumed that also the damaged IBC had been exposed to both UV radiation and nitric acid, probably outdoors. KW - Polyethylene KW - Nitric acid KW - UV radiation KW - Outdoor weathering KW - Resistance PY - 2018 DO - https://doi.org/10.3139/120.111148 SN - 0025-5300 VL - 60 IS - 3 SP - 257 EP - 264 PB - Carl Hanser Verlag CY - München AN - OPUS4-44567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Digitale Umweltsimulation am Beispiel der Photooxidation von Polymeren N2 - Die Umweltwirkungen auf ein Material werden als Überlapp der Funktionskurven von Materialempfindlichkeit und einwirkenden Umweltparametern betrachtet. Wenn entweder die Empfindlichkeit oder die Beanspruchungen Null sind, ergibt sich auch keine Umweltwirkung und bei beidseitig Werten größer Null das jeweilige Produkt der beiden. Die Akkumulation der nicht-reversiblen Effekte über die Zeit und allen Eigenschaftsänderungen entspricht der Alterung des Materials für den jeweiligen Expositionszeitraum. Die digitale Umweltsimulation gliedert sich hier in drei Teilaspekte. Ein erster, rein materialwissenschaftlicher Teil hat die Aufgabe, alle relevanten Materialempfindlichkeiten experimentell zu quantifizieren. Ein zweiter – unter Umständen numerischer Teil – hat die Aufgabe, das Bauteil und seine Einbaulage zu digitalisieren und aus den makroskopischen Umgebungsbedingungen die relevanten mikroklimatischen Umweltparameter für alle Oberflächen- oder Volumenelemente zu bestimmen. In einem dritten Teil werden die Einwirkungen über den betrachteten Zeitraum berechnet und kumuliert. Dieses Konzept, das auf den so genannten Expositions-Reaktions-Funktionen (ERF) basiert, wird an Beispielen der Photoxidation erläutert. Dieses Vorgehen wurde schon beim ViPQuali-Projekt als Numerische Umweltsimulation umgesetzt. Überprüft werden muss das Modell unbedingt an einer realitätsnahen Validierungsbeanspruchung. Hier werden die ermittelten ERFs mit über den kompletten Beanspruchungszeitraum geloggten Umweltparametern gekoppelt, um die berechnete mit der experimentell erfahrenen Alterungswirkung zu vergleichen. Nur so kann sichergestellt sein, dass alle für die Anwendungsumgebung relevanten Materialempfindlichkeiten einbezogen wurden. T2 - 52. Jahrestagung der GUS CY - Stutensee-Blankenloch, Germany DA - 26.03.2024 KW - UV KW - Polymer 3R KW - Bewitterung KW - Bestrahlung PY - 2024 SN - 978-3-9826129-0-4 SP - 31 EP - 40 PB - Gesellschaft für Umweltsimulation e.V. CY - Pfinztal (Berghausen) AN - OPUS4-59830 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Geburtig, Anja A1 - Schulz, Ulrich A1 - Trubiroha, Peter T1 - „Test Tailoring“ eines künstlichen Bewitterungstests am Beispiel der Entwicklung des „Acid Dew and Fog“ Testes N2 - Häufig ist es wünschenswert, für neue Materialien oder Anwendungen künstliche Bewitterungsverfahren zu benutzen, die auf die spezifischen Anforderungen besser zugeschnitten sind, als es bei bestehenden standardisierten Verfahren der Fall ist. Nachdem man die spezifischen Parameter der Beanspruchung unter Anwendungsbedingungen und die spezifische Empfindlichkeit des Materials erfasst hat, beginnt ein Prozess, der als „Test Tailoring“ häufig abstrakt verwendet, auf den aber nur selten näher eingegangen wird. Genau dieser Prozess soll hier am Beispiel der Entwicklung eines künstlichen Bewitterungstests unter saurer Beaufschlagung, dem in der BAM entwickelten Acid Dew and Fog Test, beispielhaft erläutert werden. T2 - 47. Jahrestagung der GUS 2018, Umwelteinflüsse erfassen, simulieren, bewerten CY - Pfinztal (Berghausen), Germany DA - 21.03.2018 KW - Test Tailoring KW - Bewitterung KW - Acid Dew and Fog KW - Umweltsimulation PY - 2018 VL - 47 SP - Vortrag V4, 45 EP - 54 PB - Gesellschaft für Umweltsimulation e.V. CY - Pfinztal AN - OPUS4-45412 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. T1 - Exposure response function for a quantitative prediction of weathering caused aging of polyethylene N2 - The exposure response function of the carbonyl formation over the bulk has been determined for a high-density polyethylene of a thickness of 200 μm, which was used as a weathering reference material according to ISO TR 19032. To this end, spectral sensitivity was studied by local measurement of the effect of spectrally dispersed irradiation. Both the exposure device and the methodology of determination are described. The temperature dependency of photooxidation was determined by UV exposure at various temperatures between 23 and 80 °C. Deviations from linearity and thus reciprocity below 40 °C are discussed and assumed to be related to diffusion limitations. An Arrhenius approach –based on data of linear carbonyl formation – has been incorporated into the exposure response function. Using this exposure response function, aging in terms of the distribution of a quantitative property change over a plastic component can be predicted for a specific outdoor location with real chronologic weather data as input for the exposure. Thus, artificial and natural weathering can be linked and compared. The established exposure response function has been validated by outdoor exposure results from the literature. If an estimated diffusion limitation is taken into consideration, calculations and published data are in good agreement. KW - Irradiation KW - Weathering KW - Spectral sensitivity KW - Temperature dependency KW - Spectral irradiation PY - 2019 DO - https://doi.org/10.3139/120.111348 SN - 0025-5300 VL - 61 IS - 6 SP - 517 EP - 526 PB - Carl Hanser Verlag GmbH & Co. KG AN - OPUS4-48295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. ED - Ziegahn, K.-F. T1 - Quantitative Auswertemöglichkeiten bei der spektralen Bestrahlung – Berechnung des Wirkungsspektrums N2 - Für die Bewertung des Wellenlängeneinflusses auf die Alterungsvorgänge bei der Bestrahlung UV- oder lichtempfindlicher Materialien kann die Methode der spektralen Bestrahlung angewendet werden. Im Prinzip wird dabei das linear dispergierte Spektrum einer Strahlenquelle mit kontinuierlichem Spektrum (z.B. Xe-Lampe) auf eine Probenoberfläche abgebildet, so dass Ort einer Materialänderung und Wellenlänge der Bestrahlung einander zugeordnet werden können. Nachfolgende lokal-auflösende Analysemethoden ermitteln eine Eigenschaftsänderung an einem spezifischen Ort der Probe, aus dem sich dann die Bestrahlungswellenlänge ergibt. Der verwendete Aufbau wird beschrieben. Es wird an einem ausgewählten Beispiel gezeigt, wie durch geeignete Anbindung eines Messsystems zur Bestimmung der spektralen Bestrahlungsstärke und ortsaufgelöste Messungen der Eigenschaftsänderungen eine quantitative Auswertung realisiert werden kann. Der Einfluss nichtlinearer Alterungsverläufe wird diskutiert. Grenzen der Methode werden aufgezeigt und Erweiterungsmöglichkeiten dargestellt. T2 - 46. Jahrestagung der GUS CY - Stutensee-Blankenloch, Germany DA - 22.03.2017 KW - UV-Bestrahlung PY - 2017 SN - 978-3-9816286-9-2 SP - V 8, 91 EP - 99 AN - OPUS4-42578 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meurer, Maren T1 - Is olypropylene relevant for microplastic analytics? N2 - Nowadays, in every terrestrial and aquatic ecosystem, even in the remotest areas, small residues of plastics, the so called microplastic (MP) can be found. MPs are particles with a size of 1-1000 µm (ISO/TR 21960:2020), mainly containing synthetic polymers like polyethylene (PE), polypropylene (PP), polystyrene (PS) or polyethylene terephthalate (PET). Even styrene-butadiene rubber (SBR) as an indication for tire wear is included due to similar particle formation. To understand the MPs consequences to the environment, it is of high priority to capture its extent of contamination. It is surprising that in the analysis of polymer masses in environmental samples, PE, PS and SBR are often detected, but only small amounts of PP, although this is the second most commonly produced standard plastic and many MP particles originate from carelessly disposed packaging materials. This presentation provides hypotheses about the reasons of rare PP identification and mass quantification in environmental samples. Different investigations of pristine PP and representative environmental samples, including the pre-treatment by Accelerated Solvent Extraction (ASE) or with density separation followed by the thermal extraction / desorption gas chromatography-mass spectrometry (TED-GC/MS) are presented. The results are discussed according to the material properties and a possible degradation mechanism under different weathering conditions which indicate less stability under relevant storage conditions. T2 - Society of Environmental Toxicology and Chemistry CY - Dublin, Ireland DA - 30.04.2023 KW - Sample preparation KW - Polypropylene KW - Microplastic KW - Degradation PY - 2023 AN - OPUS4-57474 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radunz, Sebastian A1 - Kraus, Werner A1 - Bischoff, F. A. A1 - Emmerling, Franziska A1 - Resch-Genger, Ute A1 - Tschiche, Harald T1 - Temperature- and Structure-Dependent Optical Properties and Photophysics of BODIPY Dyes N2 - We report on the temperature- and structural-dependent optical properties and photophysics of a set of boron dipyrromethene (BODIPY) dyes with different substitution patterns of their meso-aryl subunit. Single-crystal Xray diffraction analysis of the compounds enabled a classification of the dyes into a sterically hindered and a unhindered group. The steric hindrance refers to a blocked rotational motion of the aryl subunit around the bond connecting this moiety to the meso-position of the BODIPY core. The energy barriers related to this rotation were simulated by DFT calculations. As follows from the relatively low rotational barrier calculated to about 17 kcal/mol, a free rotation is only possible for sterically unhindered compounds. Rotational barriers of more than 40 kcal/mol determined for the sterically hindered compounds suggest an effective freezing of the rotational motion in These molecules. With the aid of temperature-dependent spectroscopic measurements, we could show that the ability to rotate directly affects the optical properties of our set of BODIPY dyes. This accounts for the strong temperature dependence of the fluorescence of the sterically unhindered compounds which show a drastic decrease in fluorescence quantum yield and a significant shortening in fluorescence lifetime upon heating. The optical properties of the sterically hindered compounds, however, are barely affected by temperature. Our results suggest a nonradiative deactivation of the first excited singlet state of the sterically unhindered compounds caused by a conical intersection of the potential energy surfaces of the Ground and first excited state which is accessible by rotation of the meso-subunit. This is in good agreement with previously reported deactivation mechanisms. In addition, our results suggest the presence of a second nonradiative depopulation pathway of the first excited singlet state which is particularly relevant for the sterically hindered compounds. KW - Fluorescence KW - Sensor KW - Switch KW - pH KW - BODIPY KW - Dye KW - Probe KW - Synthesis KW - Photophysics KW - Mechanism PY - 2020 DO - https://doi.org/10.1021/acs.jpca.9b11859 SN - 1089-5639 VL - 124 IS - 9 SP - 1787 EP - 1797 PB - American Chemical Society AN - OPUS4-50639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Olivera, Paulo A1 - Michalchuk, Adam A1 - Marquardt, Julien A1 - Feiler, Torvid A1 - Prinz, Carsten A1 - Torresi, R. A1 - Camargo, P. A1 - Emmerling, Franziska T1 - Investigating the role of reducing agents on mechanosynthesis of Au nanoparticles N2 - Control over the bottom up synthesis of metal nanoparticles (NP) depends on many experimental factors, including the choice of stabilising and reducing agents. By selectively manipulating these species, it is possible to control NP characteristics through solution-phase synthesis strategies. It is not known, however, whether NPs produced from mechanochemical syntheses are governed by the same rules. Using the Au NPs mechanosynthesis as a model system, we investigate how a series of common reducing agents affect both the reduction kinetics and size of Au NPs. It is shown that the relative effects of reducing agents on mechanochemical NP synthesis differ significantly from their role in analogous solution-phase reactions. Hence, strategies developed for control over NP growth in solution are not directly transferrable to environmentally benign mechanochemical approaches. This work demonstrates a clear need for dedicated, systematic studies on NP mechanosynthesis. KW - Mechanochemistry KW - Metal nanoparicels PY - 2020 DO - https://doi.org/10.1039/d0ce00826e VL - 22 IS - 38 SP - 6261 EP - 6267 PB - Royal Society of Chemistry AN - OPUS4-51757 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulla, Hannes A1 - Haferkamp, Sebastian A1 - Akhmetova, Irina A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical one-pot syntheses N2 - We present an in situ triple coupling of synchrotron X-ray diffraction with Raman spectroscopy, and thermography to study milling reactions in real time. This combination of methods allows a correlation of the structural evolution with temperature information. The temperature information is crucial for understanding both the thermodynamics and reaction kinetics. The reaction mechanisms of three prototypical mechanochemical syntheses, a cocrystal formation, a C@C bond formation (Knoevenagel condensation), and the formation of a manganese-phosphonate, were elucidated. Trends in the temperature development during milling are identified. The heat of reaction and latent heat of crystallization of the product contribute to the overall temperature increase. A decrease in temperature occurs via release of, for example, water as a byproduct. Solid and liquid intermediates are detected. The influence of the mechanical impact could be separated from temperature effects caused by the reaction. KW - In situ studies KW - Mechanochemistry KW - Raman spectroscopy KW - Thermography KW - X-ray diffraction PY - 2018 DO - https://doi.org/10.1002/anie.201800147 SN - 1433-7851 SN - 1521-3773 VL - 57 IS - 20 SP - 5930 EP - 5933 PB - Wiley-VCH CY - Weinheim AN - OPUS4-44946 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Haferkamp, Sebastian A1 - Emmerling, Franziska T1 - Insights into the mechanochemical Knoevenagel condensation N2 - Mechanochemistry paves the way to simple, fast, and green syntheses, but there is a lack in understanding of the underlying mechanisms. Here, we present a universal strategy for simultaneous real-time in situ analysis, combining X-ray diffraction, Raman spectroscopy, and thermography. T2 - Bessy User Meeting 2019 CY - Berlin, Germany DA - 05.12.2019 KW - Mechanochemistry PY - 2019 AN - OPUS4-50122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - May, Anastasia T1 - Thermomechanochemical Synthesis of Pimelic Acid Cocrystals N2 - Milling temperature is a critical factor in mechanochemistry, affecting the kinetics and outcomes of reactions. In the context of cocrystallization, the influence of milling temperature on the process has been investigated for cocrystal systems pyrazinamide:pimelic acid (PZA:PA) and 4,4'-bipyridine:pimelic acid (BPY:PA). By means of temperature-controlled milling, stabilization of metastable polymorph of PZA:PA was achieved, thereby decelerating the aging process of the polymorph. This was accomplished through controlled heated milling of PZA and PA. Furthermore, we have successfully synthesized all three BPY:PA polymorphs by mechanochemistry involving controlled cooled and heated milling. In previous studies, only the most stable polymorph was obtained by mechanochemistry. T2 - 10th European Crystallography School CY - Ohrid, North Macedonia DA - 23.06.2025 KW - Mechanochemistry KW - Cocrystal PY - 2025 AN - OPUS4-63797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Terkawi, Abdal-Azim A1 - Scholz, G. A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - Strontium-coordination polymers based on tetrafluorophthalic and phthalic acids: mechanochemical synthesis, ab initio structures determination, and spectroscopic characterization N2 - Two strontium-based dicarboxylate systems [Sr(oBDC-F4)(H2O)2] (1) and [{Sr(oBDC)(H2O)2)·H2O] (2) were synthesized mechanochemically via milling of Sr(OH)2·8H2O with tetrafluorophthalic acid (H2oBDC-F4) or phthalic acid (H2oBDC), respectively. The new structures were determined ab initio from the powder X-ray diffraction (PXRD) data. Both compounds 1 and 2 crystallize in the monoclinic space group P21 /c as two-dimensional coordination polymers (2D-CPs). The determined structures were validated by extended X-ray absorption (EXAFS) data. Compounds 1 and 2 show different thermal stabilities. The fluorinated CP 1 is decomposed at 300 °C while the nonfluorinated CP 2 transforms into a new phase after thermal treatment at 400 °C. The two hydrated CPs exhibit small surface areas which increase after the thermal posttreatment for 1 but remains unchanged for the dehydrated sample of 2. Dynamic vapor sorption (DVS) experiments indicate that both the dehydrated and hydrated samples of 2 depict no significant differences in their adsorption isotherms. The DVS of water indicates that the phase transition after thermal posttreatment of 2 is irreversible. KW - Mechanochemistry KW - XRD KW - NMR PY - 2017 DO - https://doi.org/10.1039/c7dt02564e SN - 1477-9226 SN - 1477-9234 VL - 46 IS - 37 SP - 12574 EP - 12587 PB - The Royal Society of Chemistry CY - Cambridge AN - OPUS4-42261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria T1 - Synthesis of bimetallic nickel nanoparticles as catalysts for the Sabatier reaction N2 - Nanoparticles (NPs) have become important materials for a variety of chemical technologies. The enhanced surface-area-to-volume ratio of NPs, making them excellent for use as catalyst, in analytical assays, and for antimicrobial applications. Nickel NPs have exhibited immense potential as important catalyst for the Sabatier reaction, i.e. converting waste to energy via transformation of CO2 into CH4, and could replace the rare earth elements such as Ru, PT, or Rh. In this work we describe the solvothermal synthesis of monometallic and bimetallic nickel nanoparticles. Monodisperse monometallic Ni NPs were synthesized using Oleylamin as solvent and reducing agent. The nanoparticles were investigated using small angle scattering (SAXS), scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDX), showing that the NPs are stable while the surface is not entirely covered. However, Ni has a high propensity to undergo oxidation, and becoming deactivated by coke formation. Hence, we further explore the preparation of bimetallic NPs, where a second metal is added to stabilize the Ni. Bimetallic Cu-Ni NPs were synthesized by simultaneous solvothermal reduction. These bimetallic NPs exhibit excellent catalytic properties are promising candidates to be used as catalysts for efficient energy storage. T2 - Adlershofer Forschungsforum 2019 CY - Berlin, Germany DA - 11.11.2019 KW - Nanoparticles KW - Catalysis KW - Synthesis PY - 2019 AN - OPUS4-50173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tuma, Dirk A1 - Mady, A. H. A1 - Baynosa, M. L. A1 - Saad, M. A1 - Dhakal, G. A1 - Kim, W. K. A1 - Shim, Jae-Jin T1 - Morphology-engineered hollow NiTiO₃/C–Ag/Ag₃PO₄ S-scheme heterojunction photocatalyst: mechanistic insights into sunlight-driven tetracycline degradation N2 - Tetracycline (TCH), a widely used antibiotic, persists in aquatic and terrestrial environments, posing ecological risks and accelerating antibiotic resistance. To address this, we report a hollow-structured NiTiO₃/C–Ag/Ag₃PO₄ (NT/C–AAP) photocatalyst—the first hollow-type nickel titanate—synthesized via a self-template solvothermal route followed by photodeposition. The catalyst integrates key design strategies—hollow architecture, oxygen vacancies, carbon coating, and an S-scheme heterojunction—to optimize photocatalytic performance. The hollow structure enhances light harvesting via internal scattering, oxygen vacancies facilitate O2 adsorption and superoxide (O₂•⁻) generation, and the S-scheme heterojunction effectively suppresses electron–hole recombination while preserving strong redox potential. NT/C–AAP achieved 96% TCH degradation within 1 h and 82% mineralization in 3 h under solar light, far exceeding core–shell (18%) and aggregated (47%) NiTiO₃-based catalysts. Complete removal was realized within 40 min under 400 W visible light. The catalyst maintained 96% activity after five cycles, confirming excellent durability. Compared with previously reported NiTiO₃ photocatalysts, NT/C–AAP delivered a 50–400% performance enhancement arising from its engineered hollow structure and improved electronic properties. Mechanistic studies identified O₂•⁻ and •OH radicals as dominant species, validating the role of morphology and interface engineering in directing charge separation and redox activity. Additionally, a catalyst performance index was proposed to facilitate comparison across diverse conditions. Overall, this work introduces a novel, durable photocatalyst that links structural design to functional performance and demonstrates strong potential for practical environmental remediation. KW - Heterojunction photocatalyst KW - Photodegradation KW - Tetracycline PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655946 DO - https://doi.org/10.1007/s42114-025-01600-x SN - 2522-0128 VL - 9 IS - 2 SP - 1 EP - 19 PB - Springer Nature CY - London AN - OPUS4-65594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwibbert, Karin A1 - de Eulate Pérez, Elisa García A1 - Wen, Keqing A1 - Voss, Heike A1 - Thiele, Dorothea A1 - Richter, Anja M. A1 - Bonse, Jörn T1 - Escherichia coli repellence via laser-induced periodic surface structures (LIPSS) on titanium: Critical role of biofilm-associated gene expression N2 - The inconsistency in the observed bacteria-repellent effects of laser-induced surface textures remains a subject of scientific debates. With E. coli TG1 as test strain, we performed biofilm formation assays on ultrashort pulse laser textured titanium. Samples covered with low spatial frequency LIPSS (LSFL) of periods around 750 nm or with high spatial frequency LIPSS (HSFL) featuring smaller periods around 100 nm were processed on polished samples. While LSFL significantly reduce the number of adhering bacteria compared to the polished reference, HSFL do not. Simultaneously, we concentrate our study on bacterial strategies employed for biofilm formation, that is the transcription of the biofilm-associated genes csgB, involved in primary adhesion to a surface, and wza, participating in biofilm maturation. Promoter regions of these genes were cloned into a promotor probe plasmid with the green fluorescent protein GFP+ as reporter and transferred into the test strain. As indicated by the fluorescence intensity of the reporter protein, among the bacteria colonizing LSFL-covered areas, a markedly higher proportion of cells transcribing csgB or wza were detected, compared to the bacterial populations colonizing the polished or HSFL-covered areas. To our knowledge, this is the first study indicating that the antifouling effect of LSFL topographies can be counteracted when bacteria activate biofilm-associated genes. KW - Laser-induced periodic surface structures (LIPSS) KW - Titanium KW - Biofilm KW - Antifouling KW - Gene expression KW - Fluorescence microscopy PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655572 DO - https://doi.org/10.1016/j.apsusc.2026.166363 SN - 0169-4332 VL - 730 SP - 1 EP - 9 PB - Elsevier B.V. AN - OPUS4-65557 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gugin, Nikita A1 - Villajos Collado, José Antonio A1 - Dautain, O. A1 - Maiwald, Michael A1 - Emmerling, Franziska T1 - Optimizing the Green Synthesis of ZIF-8 by Reactive Extrusion Using In Situ Raman Spectroscopy N2 - We report the scale-up of a batch solid synthesis of zeolitic imidazolate framework-8 (ZIF-8) for reactive extrusion. The crystalline product forms in the extruder directly under the mixture of solid 2-methylimidazole and basic zinc carbonate in the presence of a catalytic amount of liquid. The process parameters such as temperature, liquid type, feeding rate, and linker excess were optimized using the setup specifically designed for in situ Raman spectroscopy. Highly crystalline ZIF-8 with a Brunauer–Emmett–Teller (BET) surface area of 1816 m2 g–1 was quantitatively prepared at mild temperature using a catalytic amount of ethanol and a small excess of the linker. Finally, we developed a simple and comprehensive approach to evaluating the environmental friendliness and scalability of metal–organic framework (MOF) syntheses in view of their large-scale production. KW - Mechanochemistry KW - In situ Raman KW - Large-scale processing KW - Metal−organic frameworks KW - Twin-screw extrusion (TSE) PY - 2023 DO - https://doi.org/10.1021/acssuschemeng.2c07509 SN - 2168-0485 VL - 11 IS - 13 SP - 5175 EP - 5183 PB - ACS Publications AN - OPUS4-57366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Božičević, Lucija A1 - Altmann, Korinna A1 - Hildebrandt, Jana A1 - Knigge, Xenia A1 - Vrček, Valerije A1 - Peranić, Nikolina A1 - Kalcec, Nikolina A1 - Vinkovic Vrcek, Ivana T1 - Estrogenic activity of plastic nanoparticles mixture under in vitro settings N2 - The plastic value chain, central part of modern living, caused environmental pollution and bioaccumulation of plastic nanoparticles (PNPs). Their ubiquitous presence in different environmental and biological compartments has become a serious threat to human health and ecosystems. Frequently used plastic materials such as polypropylene (PP), polystyrene (PS) and polyethylene (PE) have been detected in the form of PNPs in the food chain, soil, water and air, as well as in human feces and blood. In this study, we aimed to provide novel insights in endocrine disrupting properties of PNPs using in vitro estrogen receptor (ER) transactivation assay. The effects of PP-NPs, PE-NPs and PS-NPs and their mixture on T47D-KBluc cell line stably transfected with luciferase as reporter enzyme was evaluated by means of cytotoxicity, cellular uptake and ER activation. Tested dose range for PNPs was 0.001 – 10 mg/L. Both cellular uptake and cytotoxicity for all PNPs was found to be dose-dependent. Only the highest dose of PP-NPs and PE-NPs induced apoptosis and cell death, while PS-NPs were not cytotoxic in tested dose range. For tested concentrations, PP-NPs and PE-NPs showed significant agonistic activity on ER, while PS-NPs cannot be considered ER active. When, applied as mixture, PNP demonstrated additive toxicity effects compared to the effect of each individual PNPs. Additivity was also observed for ER agonistic effect of PNPs mixture according to the benchmark dose-addition modelling approach. This study provides missing science-based evidence on endocrine disrupting effects of PE-NPs, PP-NPs, PS-NPs and their mixtures and highlights the importance of considering unintentional, aggregate and combined exposure to different PNPs in risk management. KW - Risk assessment KW - Nanoplastics KW - Estrogenic activity of plastic nanoparticles PY - 2024 DO - https://doi.org/10.1039/D3EN00883E SN - 2051-8153 VL - 11 IS - 5 SP - 2112 EP - 2126 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lee, P.-W. A1 - Kaynak, T. A1 - Al-Sabbagh, Dominik A1 - Emmerling, Franziska A1 - Schalley, C. T1 - Effect of Perfluorinated Side-Chain Length on the Morphology, Hydrophobicity, and Stability of Xerogel Coatings N2 - Superhydrophobic surfaces can be quickly formed with supramolecular materials. Incorporating low-molecular-weight gelators (LMWGs) with perfluorinated chains generates xerogel coatings with low surface energies and high roughness. Here, we examine and compare the properties of the xerogel coatings formed with eight different LMWGs. These LMWGs all have a trans-1,2-diamidocyclohexane core and two perfluorinated ponytails, whose lengths vary from three to ten carbon atoms (CF3 to CF10). Investigation of the xerogels aims to provide in-depth information on the chain length effect. LMWGs with a higher degree of fluorination (CF7 to CF10) form superhydrophobic xerogel coatings with very low surface energies. Scanning electron microscopy images of the coatings show that the aggregates of CF5 and CF7 are fibrous, while the others are crystal-like. Aggregates of CF10 are particularly small and further assemble into a porous structure on the micrometer scale. To test their stabilities, the xerogel coatings were flushed multiple times with a standardized water flush test. The removal of material from the surface in these flushes was monitored by a combination of the water contact angle, contact angle hysteresis, and coating thickness measurements. A new method based on image processing techniques was developed to reliably determine the change of the coating thickness. The CF7, CF9, and CF10 surfaces show consistent hydrophobicity and coating durability after repetitive flushing tests. The length of the perfluorinated side chains thus has a significant effect on the morphology of the deposited xerogel coatings, their roughness, and, in consequence, their hydrophobicity and mechanical durability. KW - Coating materials KW - Amorphous materials KW - Hydrophobicity KW - Materials Stability PY - 2021 DO - https://doi.org/10.1021/acs.langmuir.1c02341 SN - 1520-5827 VL - 37 IS - 49 SP - 14390 EP - 14397 PB - ACS Publications AN - OPUS4-54071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmitt, M. A1 - Altmann, Korinna A1 - Fengler, Petra A1 - Gehde, M. T1 - Air-based polyethylene fragmentation with high yield to form microplastic particles as reference material candidates N2 - Microplastic particles with sizes between 1 to 1000 μm are widely distributed worldwide. Origin, transport pathways and fate are poorly known, as sampling, sample preparation and detection methods are major challenges. In addition, reference materials that mimic environmental particles are lacking. Most challenging is the yield of MP particle production and the need for resource-intensive grinding with liquid nitrogen. In this paper, a machine is designed to produce aged microplastic particles as reference material candidates with high yield. The machine is based on ultraviolet aging of a thin foil and mechanical fragmentation using clean air. An example of aging and fragmentation of high density polyethylene with additional physical and chemical characterization of shape, size, aging state by carbonyl index and density is presented. KW - Microplastics KW - Degradation of polyethylene KW - Air fragmentation KW - Microplastics reference material PY - 2023 DO - https://doi.org/10.1002/appl.202200121 SP - 1 EP - 18 PB - Wiley online library AN - OPUS4-57203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Simone T1 - Influence of the pH Value to the Degradation of Ester-Based Thermoplastic Polyurethanes N2 - Microplastics are solid polymeric particles with a size of 1-1000 μm (ISO/TR21960:2020), which can be emitted from mismanaged waste into the environment, where microplastic is now ubiquitous. What happens to the microplastics after ending up in the environment, which risks entail and what effects it has are not sufficiently clarified up to now. The most certain issue is that the plastic particles in the environment are exposed to natural ageing, are fragmenting and degrading, such that the potential risk to ecosystems and humans is increasing due to the formation of smaller and smaller particles, potentially even including nanoplastics, if these are ingested before their further degradation. Therefore, and in view of a possible registration of polymers under REACH in the future, it is necessary to investigate the degradation of thermoplastic polyurethanes (TPU) regarding hydrolysis stability to evaluate possible risks and effects to the environment. In the present studies, one thermoplastic polyurethane – with and without hydrolysis stabilizer – is exposed to different pH buffers at 50°C for 14 days to investigate hydrolysis depending to different pH values (acid, alkali and neutral) based on OECD guideline TG111. The hydrolysis behavior of the TPUs is characterized by surface sensitive techniques and on bulk properties. First degradation effects can be detected by SEC. Hydrolysis, especially under acidic and basic conditions, leads to chain scissions to lower molecular masses. Furthermore, the degradation products which indicate the structure of the bulk material were detected by thermo-analytical methods like TGA-FTIR for the small degradation products and the thermo extraction/desorption-gaschromatography/mass spectrometry (TED-GC/MS) for bigger degradation products. Acidic and basic hydrolysis shows the same degradation behavior which is caused by a preferred scission of the ester and urethane functionalities. Surface-sensitive techniques such as XPS demonstrate less carboxylic acid formation at acidic than at alkaline pH value in the TPU without stabilator, where as the TPU with stabilator ages to the same extent in both pH ranges. Altogether, the hydrolysis of TPUs – independently of added stabilizer or not – in acid and alkali environment is accelerated compared to the neutral hydrolysis. T2 - SETAC CY - Dubin, Ireland DA - 30.04.2023 KW - Degradation KW - Thermoplastic Polyurethane KW - Microplastic KW - Polymer Hydrolysis KW - Polymer 3R KW - REACH PY - 2023 AN - OPUS4-58906 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiesner, Yosri T1 - Erfassung von Degradationsprodukten und Additiven sowie temperaturspezifische Pyrolyseprodukte mittels TED-GC/MS N2 - Im der Präsentation werden, neben der Möglichkeit der Mikroplastikquantifizierung, auf weitere Anwendungsfelder der Methode TED-GC/MS eigegangen. Dies beinhaltet die Erfassung von Degradationsprodukten UV/O2 geschädigter Polymere und die Detektion von Additiven. Die Optimierung der Methode betreffend Messzeit und materialspezifischer Messanforderung sind ebenfalls Gegenstand. T2 - Kolloquium Massenspektrometrie von Polymeren CY - Berlin, Germany DA - 09.05.2023 KW - TED-GC/MS KW - Polymere KW - Degradation KW - Additive PY - 2023 AN - OPUS4-57480 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -