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Quantitative EDS analysis on graphene related 2D materials
No full textThe elemental analysis of solid matter by means of the Energy-Dispersive X-Ray Spectrometry (EDS) is meanwhile posible as a quick (seconds!) and more and more accurate analysis via standardsless (instantaneous) quantification. The sensitivity & quantification accuracy for light elements (C, O,..) has significantly increased in the recent years. The availability via table-top SEMs with incorporated EDS is also enhanced.
Further, the EDS analysis at an SEM is well-standardized, see ISO/TC 202 Microbeam Analysis & VAMAS/ TWA 37 Quantitative Microstructural Analysis in good liaisonships with ISO/TC 229 Nanotechnologies.
It is demostrated that key parameters such as oxygen-to-carbon atomic-% ratio and impurities can be realibly measured, with XPS as a reference method. Various EDS spectrometers and analysis conditions are tested and the validity of the EDS quantification of an ionic liquid of well-defined chemical composition is demonstrated.
Next steps are to launch a corresponding VAMAS interlaboratory comparison and to discuss within ISO/TC 229 towards inclusion of EDS as a routine method for the elemental analysis of GR2M into the ISO/TS 23359 Nanotechnologies — Chemical characterization of GR2Ms in powders and suspensions
Black ink from antiquity to the Middle Ages
No full textIl nostro lavoro di ricerca al BAM si concentra sul passaggio dagli inchiostri a base di fuliggine, comuni nell'antichità, agli inchiostri ferro-gallici, comunemente usati nel Medioevo. Con l'obiettivo di creare una storia dettagliata degli inchiostri neri, abbiamo elaborato un protocollo non invasivo per raccogliere dati statisticamente rilevanti sugli inchiostri da manoscritti datati e localizzati che coprono un ampio arco temporale e diverse aree geografiche.
Il primo passo del nostro protocollo consiste nella selezione effettuata mediante riflettografia NIR e IRR. Le differenze ottiche tra gli inchiostri a base di carbonio, tannino e ferro-gallio sono meglio riconoscibili confrontando la loro risposta alla luce infrarossa: l'inchiostro a base di carbonio ha un colore nero intenso, l'inchiostro ferro-gallico diventa trasparente al di sopra dei 1400 nm e l'inchiostro a base di tannino scompare a circa 750 nm. abbiamo semplificato l'analisi utilizzando un piccolo microscopio USB con LED NIR (940 nm) e UV (395 nm) integrati, oltre a una fonte di luce bianca esterna. Confrontando le immagini sotto illuminazione bianca e nel vicino infrarosso, determiniamo la tipologia di inchiostro osservando i cambiamenti nell'opacità dell'inchiostro. In questo caso, gli inchiostri a base di carbonio non mostrano alcuna variazione di opacità quando illuminati con lunghezza d'onda NIR, mentre l'opacità degli inchiostri ferro-gallici cambia notevolmente e gli inchiostri tanninici diventano trasparenti. La nostra recente scoperta che gli inchiostri misti carbonio/ferro-gallici erano piuttosto diffusi nella tarda antichità e nell'alto Medioevo ci ha suggerito di tornare al metodo IRR convenzionale.
Il secondo passo del protocollo prevede l'analisi micro-XRF per identificare i componenti inorganici dell'inchiostro. Nel caso degli inchiostri ferro-gallici, stabiliamo le impronte digitali, ovvero i rapporti caratteristici tra i componenti vitriolici dell'inchiostro e l'elemento principale, ferro
Detektion von Bindefehlern mittels neuronaler Netze bei DED-Arc/M von Aluminium anhand von Echtzeit- Schweißstromquellendaten
No full textMit der Anwendung des Schutzgasschweißens für additive Strukturen wird aufbauend auf Machine-Learning-Modellen, welche bereits zum Überwachen beim Verbindungsschweißen erforscht wurden, ein tiefes neuronales Netz (DNN) zum Monitoring beim DED-Arc/M von Aluminium vorgestellt. Ziel des Machine Learning Modells ist das Identifizieren von Bindefehlern in den aufgebauten Volumina mit prozessbegleitend gemessenen Schweißstromquellensignalen als Input. Es werden durch Algorithmen Merkmalsvariablen in der Vorverarbeitung der Daten extrahiert und die Korrelation zwischen den Merkmalsvariablen und den Bindefehlern analysiert. Durch den vorgestellten Algorithmus werden diese automatisiert als Input an ein DNN übergeben. Diese Arbeit untersucht die Genauigkeit der Klassifizierung von verschiedenen DNN-Architekturen mit jeweils 4 verdeckten Schichten. Als Trainings- und Testsatz werden randomisiert extrahierte Merkmale von defektfreien und fehlerhaften Proben verwendet, wobei Bindefehler zum Teil absichtlich provoziert werden. Das entwickelte neuronale Netz erkennt anhand signifikanter Merkmale aus den Strom- und Spannungsdaten Bindefehler mit einer Genauigkeit von ca. 90%
Real-Time Monitoring and Temperature Control for Optimized Polymorph Engineering
No full textIntegrating real-time monitoring with precise temperature control and mechanochemical processing represents a transformative approach to the controlled engineering of polymorphic forms in molecu-lar solids. Combining these methodologies overcomes the limitations of traditional solution-based or purely thermal approaches, enabling access to metastable or otherwise elusive polymorphs under milder and more sustainable conditions. Recent studies have shown that mechanochemical trans-formations proceed through distinct kinetic stages, including prolonged induction periods that can be tuned by adjusting the mechanical energy input[1]. These induction periods are associated with pro-cesses of mechanical activation, such as the accumulation of defects and increased surface energy, which lower the effective energy barriers for polymorphic transitions. Crucially, it is the total accumu-lated mechanical energy, rather than the duration or intensity of milling alone, that dictates the onset of polymorphic conversion, offering a new dimension of kinetic control[2-5].
Variable temperature ball milling reveals that the temperature required to induce polymorphic trans-formations can be significantly lower than under conventional thermal methods. For instance, tran-sitions that typically require high temperatures under equilibrium conditions can be achieved at sub-stantially lower temperatures in the presence of mechanical activation. This has been demonstrated in cocrystal systems such as nicotinamide-pimelic acid and isonicotinamide-glutaric acid, where the transition temperature was lowered by up to 25°C[2,3]. Real-time, in situ powder X-ray diffraction and temperature monitoring are essential for capturing transient phases and elucidating the interplay between thermal and mechanical effects. This confirms that combining mechanical energy with con-trolled temperature not only accelerates transformation kinetics, but also expands the accessible polymorphic landscape [2,3].
Collectively, these advances underscore the potential of real-time monitored, temperature-controlled mechanochemistry as a robust platform for the selective design and manufacturing of polymorphs. This approach provides unprecedented control over solid-state reactivity and opens new avenues for the sustainable and targeted engineering of functional materials and pharmaceuticals
Mechanochemical innovations for sustainable synthesis of framework materials and industrial scaleup
No full textMechanochemistry has emerged as a powerful approach for sustainable materials synthesis and processing, with significant potential to meet the UN Sustainable Development Goals. This presentation will highlight our recent advancements in understanding, monitoring, and scaling-up mechanochemical synthesis of framework materials, focusing on the balance between fundamental understanding of reaction mechanisms and its practical applications in energy storage and energy transfer materials.
A central focus of our work has been the development and application of time-resolved in situ monitoring techniques for mechanochemical processes. Our research on real-time synchrotron X-ray diffraction has enabled unprecedented insights into reaction pathways and kinetics. Recently, we have successfully applied energy-dispersive X-ray diffraction for time-resolved in situ monitoring of reactive extrusion, marking a significant step towards ‘lighting up’ industrial-scale mechanochemistry.
Bridging fundamental understanding with practical applications, we have explored the mechanochemical synthesis of functional materials for energy storage and transfer, making process in the mechanochemical synthesis of highly proton-conductive metal phosphonates, demonstrating the potential of mechanochemistry to manufacture advanced materials for energy applications
Robotic Olfaction in Action: Field Applications and Results from Current Research
No full textIn recent decades, robotics, particularly in environmental monitoring, has made significant advances. Robots of various forms and sizes have become essential tools for data collection in environmental research. Mobile Robot Olfaction (MRO) involves mobile robots equipped with gas sensors and requires the integration of multiple disciplines, including signal processing, machine perception, autonomous navigation, and pattern recognition. Common applications of MRO include mapping gas distributions, locating and detecting gas sources, and tracking gas plumes. Aerial Robot Olfaction (ARO) is a specialized branch of MRO that adapts these concepts to aerial robots, addressing the challenges of airborne gas sensing.
This presentation highlights recent developments and results from ongoing research projects in MRO and ARO, with a focus on real-world deployment scenarios and the challenges encountered in practice
Robotic Olfaction in Action: Field Applications and Results from Current Research
No full textIn recent decades, robotics, particularly in environmental monitoring, has made significant advances. Robots of various forms and sizes have become essential tools for data collection in environmental research. Mobile Robot Olfaction (MRO) involves mobile robots equipped with gas sensors and requires the integration of multiple disciplines, including signal processing, machine perception, autonomous navigation, and pattern recognition. Common applications of MRO include mapping gas distributions, locating and detecting gas sources, and tracking gas plumes. Aerial Robot Olfaction (ARO) is a specialized branch of MRO that adapts these concepts to aerial robots, addressing the challenges of airborne gas sensing.
This presentation highlights recent developments and results from ongoing research projects in MRO and ARO, with a focus on real-world deployment scenarios and the challenges encountered in practice
Design, Structure and Performance of Fe-N-C Catalysts Based on Active-Site Imprinting
No full textAtomically dispersed M-N-C catalysts such as Fe-N-Cs are most promising alternatives for precious metal-based catalysts for several energy conversion reactions. Early reports on such materials date back to the 1960´s, when Jasinski pioneered the research based on tetrapyrrolic phthalocyanine macrocycles which were inspired by natural transition metal porphyrin complexes present in enzyme active sites. For decades, the selective synthesis of these catalysts was complicated by the formation of side phases due to the harsh reaction conditions facilitating side phase formation. In 2018, we introduced a mild procedure, which is conservative toward the carbon support and leads to atomically dispersed Fe-N4 site formation at temperatures as low as 80 °C in a wet-chemical step, essentially decoupling the preparation of the N-C backbone from the preparation of the active sites. The key concept therein is the so-called active-site imprinting into the N-C backbone using pyrolytic template ion reactions, allowing for high concentrations of N4 sites resulting in more than 3 at.% of Fe in atomically dispersed phase. Using the same precursor that is used for the preparation of phthalocyanines, we were able to produce atomically-dispersed single-site Fe-N-Cs that consist of tetrapyrrolic FeN4 complexes. The tetrapyrrolic Fe-N-C derivatives are highly active and extraordinary selective electrocatalysts for the oxygen reduction reaction. The well-defined and homogeneous active site structure allows to quantify the intrinsic catalytic activity of the materials in acid and base, reveal insights into the electrocatalytic mechanism and to reveal distinct degradation mechanism upon storage and electrochemical cycling. Herein, the general synthetic strategy of active-site imprinted catalysts will be discussed mainly based on both Mg-ion and Zn-ion templating towards “designed” Fe-N-C catalysts. The tetrapyrrolic active sites will be discussed regarding structure, activity, selectivity and durability. This hopefully stimulates a fruitful discussion of the perspectives in the field
From Genes to Black Rust: Genomic insights into corrosive methanogens
No full textWithin the past ten years, genetic evidence has been increasing for the direct role that microbes play in microbiologically influenced corrosion (MIC), also known as biocorrosion or biodeterioration. One prominent example is the correlation between the corrosion of metal and the presence of genes encoding an extracellular [NiFe]-hydrogenase (MIC hydrogenase) in the methanogenic archaeon, Methanococcus maripaludis. In this study, DNA sequencing and bioinformatic analysis were used to classify the MIC hydrogenase as belonging to a core set of genes, the MIC core, found so far in Methanococci and Methanobacteria classes of methanogens. Genetic evidence is provided for the mobilization of the MIC core via multiple mechanisms, including a horizontal gene transfer event from Methanobacteria to Methanococci and a newly described MIC-transposon. A detailed comparison of M. maripaludis genomes further pointed to the relevance that cell wall modifications involving N-glycosylation of S-layer proteins and the MIC hydrogenase likely play in methanogen-induced MIC (Mi-MIC). Microscopic analysis of corrosive methanogens encoding the MIC core indicated that Methanobacterium-affiliated strain IM1 can form extensive biofilms on the surface of corrosion products whereas individual cells of M. maripaludis Mic1c10 were only found localized to crevices in the corrosion layer. An updated model of Mi-MIC involving two modes of action is presented, which predicts that the propensity of cells to adhere to iron surfaces directly influences the rate of corrosion due to the localization of the MIC hydrogenase at the metal-microbe interface
Vom Experiment zur semantischen Wissensrepräsentation: Datenstandards und Interoperabilität in der Materialcharakterisierung
No full textIm Zeitalter der digitalen Transformation rückt die strukturierte Erfassung und semantische Verknüpfung von Materialcharakterisierungsdaten immer stärker in den Fokus, um eine effiziente Nutzung über Disziplin- und Projektgrenzen hinweg zu gewährleisten. Dabei bilden etablierte Datenstandards und semantische Technologien sowie Ontologien die Grundlage für eine nach FAIR-Kriterien aufgebaute Dateninfrastruktur, die sowohl maschinenlesbare als auch nachvollziehbare Wissensrepräsentationen ermöglicht.
In dieser Präsentation sollen Prinzipien interoperabler Datenarchitekturen erläutert werden, wobei auf die Bedeutung normkonformer Modelle und semantischer Konzeptualisierungen eingegangen wird. Dabei wird der steigende Bedarf an verlässlichen, reproduzierbaren und wiederverwendbaren Daten im Bereich der Materialwissenschaft und Werkstofftechnik adressiert, der insbesondere die Materialcharakterisierung und Werkstoffprüfung vor neue Herausforderungen stellt. Hinsichtlich der angestrebten Möglichkeiten zum erleichterten Datenaustausch kommen einheitlichen Datenformaten und -beschreibungen eine besondere Bedeutung zu.
Anhand ausgewählter Publikationen und Demonstratoren wird aufgezeigt, wie Ontologien als verbindende Zwischenschicht unterschiedliche Material- und Verfahrensdomänen konsistent abbilden und zusammenführen können.
Ein praktischer Anwendungsfall verdeutlicht die RDF-basierte Repräsentation von Zugversuchsdaten und deren Einbettung in ein Triple-Store-Datenbank-Umfeld. Hierbei fließen Erfahrungen aus der Entwicklung und Anwendung der PMD Core Ontology (PMDco) sowie normenkonformer Ontologien (z.B. Tensile Test Ontology, TTO) ein, welche im Rahmen des Projektes Plattform MaterialDigital (PMD, materialdigital.de) erstellt und betrachtet wurden. Darüber hinaus werden weitere methodische Ansätze und Entwicklungen aus diesem Projekt illustriert