TY - JOUR
A1 - Davison, Nathan
A1 - Hemingway, Jack M.
A1 - Wills, Corinne
A1 - Stolar, Tomislav
A1 - Waddell, Paul G.
A1 - Dixon, Casey M.
A1 - Barron, Luke
A1 - Dawson, James A.
A1 - Lu, Erli
T1 - Mechanochemical Synthesis of a Sodium Anion Complex [Na+(2,2,2-cryptand)Na–] and Studies of Its Reactivity: Two-Electron and One-Electron Reductions
N2 - Group 1 metal molecular chemistry is dominated by a +1 oxidation state, while a 0 oxidation state is widespread in the metals. A more exotic, yet still available, oxidation state of group 1 metal is −1, i.e., alkalide. Reported as early as the 1970s, the alkalides appear in every modern inorganic chemistry textbook as an iconic chemical curiosity, yet their reactivity remains unexplored. This is due to their synthetic hurdles. In this work, we report the first facile synthesis of the archetypical alkalide complex, [Na+(2,2,2-cryptand)Na–], which allows us to unveil a versatile reactivity profile of this once exotic species.
KW - Mechanochemistry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608632
DO - https://doi.org/10.1021/acs.inorgchem.4c02914
VL - 63
IS - 32
SP - 15247
EP - 15258
PB - American Chemical Society (ACS)
AN - OPUS4-60863
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Alić, Jasna
A1 - Schlegel, Moritz-Caspar
A1 - Emmerling, Franziska
A1 - Stolar, Tomislav
T1 - Meeting the UN Sustainable Development Goals with Mechanochemistry
N2 - Chemistry traditionally relies on reactions in solution, but this method is increasingly problematic due to the scale of chemical processes and their economic and environmental impact. Handling residual chemical waste, including solvents, incurs significant costs and environmental pressure. Conversely, novel chemical approaches are needed to address pressing societal issues such as climate change, energy scarcity, food insecurity, and waste pollution. Mechanochemistry, a sustainable chemistry discipline that uses mechanical action to induce chemical reactivity without bulk solvents, is a hot topic in academic research on sustainable and green chemistry. Given its fundamentally different working principles from solution chemistry, mechanochemistry offers more efficient chemical processes and the opportunity to design new chemical reactions. Mechanochemistry has a profound impact on many urgent issues facing our society and it is now necessary to use mechanochemistry to address them. This Minireview aims to provide a guide for using mechanochemistry to meet the United Nations (UN) Sustainable Development Goals (SDGs), thereby contributing to a prosperous society. Detailed analysis shows that mechanochemistry connects with most UN SDGs and offers more cost‐efficiency than other approaches together with a superior environmental performance.
KW - Mechanochemistry
KW - SDGs
PY - 2024
DO - https://doi.org/10.1002/anie.202414745
SP - 1
EP - 3
PB - Wiley
AN - OPUS4-61108
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sechi, R.
A1 - Fackeldey, K.
A1 - Chewle, Surahit
A1 - Weber, M.
T1 - SepFree NMF: A toolbox for analyzing the kinetics of sequential spectroscopic data
N2 - This work addresses the problem of determining the number of components from sequential spectroscopic data analyzed by non-negative matrix factorization without separability assumption (SepFree NMF). These data are stored in a matrix M of dimension “measured times” versus “measured wavenumbers” and can be decomposed to obtain the spectral fingerprints of the states and their evolution over time. SepFree NMF assumes a memoryless (Markovian) process to underline the dynamics and decomposes M so that M = WH, with W representing the components’ fingerprints and H their kinetics. However, the rank of this decomposition (i.e., the number of physical states in the process) has to be guessed from pre-existing knowledge on the observed process. We propose a measure for determining the number of components with the computation of the minimal memory effect resulting from the decomposition; by quantifying how much the obtained factorization is deviating from the Markovian property, we are able to score factorizations of a different number of components. In this way, we estimate the number of different entities which contribute to the observed system, and we can extract kinetic information without knowing the characteristic spectra of the single components. This manuscript provides the mathematical background as well as an analysis of computer generated and experimental sequentially measured Raman spectra.
KW - Kinetics from experiments
KW - Separability assumption
KW - Sequential spectroscopic data
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559046
DO - https://doi.org/10.3390/a15090297
SN - 1999-4893
VL - 15
IS - 9
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-55904
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fackeldey, K.
A1 - Röhm, J.
A1 - Niknejad, A.
A1 - Chewle, Surahit
A1 - Weber, M.
T1 - Analyzing Raman spectral data without separabiliy assumption
N2 - Raman spectroscopy is a well established tool for the analysis of vibration spectra, which then allow for the determination of individual substances in a chemical sample, or for their phase transitions. In the time-resolved-Raman-sprectroscopy the vibration spectra of a chemical sample are recorded sequentially over a time interval, such that conclusions for intermediate products (transients) can be drawn within a chemical process. The observed data-matrix M from a Raman spectroscopy can be regarded as a matrix product of two unknown matrices W and H, where the first is representing the contribution of the spectra and the latter represents the chemical spectra. One approach for obtaining W and H is the non-negative matrix factorization. We propose a novel approach, which does not need the commonly used separability assumption. The performance of this approach is shown on a real world chemical example.
KW - Non-negative matrix factorization
KW - NMF
KW - Raman spectra
KW - Separability condition
KW - PCCA+
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559051
DO - https://doi.org/10.1007/s10910-020-01201-7
SN - 1572-8897
VL - 59
SP - 575
EP - 596
PB - Springer Science + Business Media
CY - Dordrecht
AN - OPUS4-55905
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stawski, Tomasz
T1 - Particle-mediated origins of mesocrystalline disorder in calcium sulfate single crystals
N2 - Calcium sulfate minerals are abundant in natural and engineered environments and they exist in the form of three hydrates: gypsum (CaSO4·2H2O), bassanite (CaSO4·0.5H2O), and anhydrite (CaSO4). Due to their relevance in natural and industrial processes, the formation pathways of these calcium sulfate phases from aqueous solution have been the subject of intensive research1.
The state-of-the-art of the calcium sulfate formation mechanisms builds upon and goes beyond what we have come to appreciate in the astounding intricacy of other mineral formation processes from ions in aqueous solutions. The original, and rather naive, 'textbook' image of these phenomena, stemming from the adaptation of classical nucleation and growth theories, has increased in complexity due to the discovery of a variety of precursor and intermediate species2. These include solute clusters (e.g. prenucleation clusters, PNCs), liquid(-like) phases, as well as amorphous and nanocrystalline solids etc.. In this context, a number of studies have already revealed that nucleation in the CaSO4-H2O system is non-classical, where the formation of the different crystalline phases involves several steps including a common amorphous precursor1, 3, 4.
In this contribution we show that the formation of the amorphous phase involves the aggregation of small primary particles into larger disordered aggregates exhibiting a "brick-in-the-wall" structure5, 6. The actual crystallization occurs by the restructuring and coalescence of the particles ("bricks") into a given calcium sulfate phase depending on the physicochemical conditions of the solution. Importantly, the rearrangement process does not continue until a (nearly-)perfect homogeneous single crystal is obtained. Instead it comes to a stop, or at least significantly slows down. Such a process thus yields a final imperfect mesocrystal, composed of smaller domains rather than a continuous crystal structure, within which the domains are separated by an amorphous (i.e. less ordered) calcium sulfate phase.
Hence, the non-classical crystallization process of CaSO4 yields a final imperfect mesocrystal with an overall morphology resembling that of a single crystal, yet composed of smaller nano-domains. Importantly, these observations reveal that organic-free calcium sulfate mesocrystals grown by a particle mediated-pathway preserve in the final crystal structure a “memory” or “imprint” of their non-classical nucleation process, something that has been overlooked until now. Furthermore, the nano-scale misalignment of the structural sub-units within these crystals can propagate through the length-scales, and be expressed macroscopically as misaligned zones/domains in large single crystals (Fig. 1). Indeed, by considering large anhydrite crystals from the famous Naica Mine (“Cueva de los cristales”) we observed a suite of correlated self-similar void defects spanning multiple length-scales7 (Fig 2). These flaws, in the macroscopic crystal, stem from “seeds of imperfection” originating from a particle-mediated nucleation pathway. Hence, building a crystal could be viewed as Nature stacking blocks in a game of Tetris, whilst slowly forgetting the games core concept and failing to fill rows completely.
T2 - Granada Münster Discussion Meeting (GMDM)
CY - Granda, Spain
DA - 30.11.2022
KW - Anhydrite
KW - Mesocrystals
KW - Calcium sulfate
KW - Bassanite
KW - Gypsum
PY - 2022
AN - OPUS4-56476
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stawski, Tomasz
T1 - Particle-mediated origins of mesocrystalline disorder in calcium sulfate single crystals
N2 - Calcium sulfate minerals are abundant in natural and engineered environments and they exist in the form of three hydrates: gypsum (CaSO4·2H2O), bassanite (CaSO4·0.5H2O), and anhydrite (CaSO4). Due to their relevance in natural and industrial processes, the formation pathways of these calcium sulfate phases from aqueous solution have been the subject of intensive research1.
The state-of-the-art of the calcium sulfate formation mechanisms builds upon and goes beyond what we have come to appreciate in the astounding intricacy of other mineral formation processes from ions in aqueous solutions. The original, and rather naive, 'textbook' image of these phenomena, stemming from the adaptation of classical nucleation and growth theories, has increased in complexity due to the discovery of a variety of precursor and intermediate species2. These include solute clusters (e.g. prenucleation clusters, PNCs), liquid(-like) phases, as well as amorphous and nanocrystalline solids etc.. In this context, a number of studies have already revealed that nucleation in the CaSO4-H2O system is non-classical, where the formation of the different crystalline phases involves several steps including a common amorphous precursor1, 3, 4.
In this contribution we show that the formation of the amorphous phase involves the aggregation of small primary particles into larger disordered aggregates exhibiting a "brick-in-the-wall" structure5, 6. The actual crystallization occurs by the restructuring and coalescence of the particles ("bricks") into a given calcium sulfate phase depending on the physicochemical conditions of the solution. Importantly, the rearrangement process does not continue until a (nearly-)perfect homogeneous single crystal is obtained. Instead it comes to a stop, or at least significantly slows down. Such a process thus yields a final imperfect mesocrystal, composed of smaller domains rather than a continuous crystal structure, within which the domains are separated by an amorphous (i.e. less ordered) calcium sulfate phase.
Hence, the non-classical crystallization process of CaSO4 yields a final imperfect mesocrystal with an overall morphology resembling that of a single crystal, yet composed of smaller nano-domains. Importantly, these observations reveal that organic-free calcium sulfate mesocrystals grown by a particle mediated-pathway preserve in the final crystal structure a “memory” or “imprint” of their non-classical nucleation process, something that has been overlooked until now. Furthermore, the nano-scale misalignment of the structural sub-units within these crystals can propagate through the length-scales, and be expressed macroscopically as misaligned zones/domains in large single crystals. Indeed, by considering large anhydrite crystals from the famous Naica Mine (“Cueva de los cristales”) we observed a suite of correlated self-similar void defects spanning multiple length-scales7. These flaws, in the macroscopic crystal, stem from “seeds of imperfection” originating from a particle-mediated nucleation pathway. Hence, building a crystal could be viewed as Nature stacking blocks in a game of Tetris, whilst slowly forgetting the games core concept and failing to fill rows completely.
T2 - ECCG: European Conference on Crystal Growth 7
CY - Paris, France
DA - 25.07.2022
KW - Anhydrite
KW - SAXS
KW - Single crystal
KW - Mesocrystal
PY - 2022
AN - OPUS4-56276
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stawski, Tomasz
T1 - Particle-mediated origins of mesocrystallinity in calcium sulfate single crystals
N2 - Calcium sulfate minerals are abundant in natural and engineered environments in the form of three phases: gypsum (CaSO4·2H2O), bassanite (CaSO4·0.5H2O), and anhydrite (CaSO4). Due to their relevance in natural and industrial processes, the formation pathways of these phases from aqueous solution have been the subject of intensive research, a number of studies have already revealed that nucleation in the CaSO4-H2O system is non-classical, The formation of the different crystalline phases involves several steps including a common amorphous precursor.
In this contribution we show that the formation of the amorphous phase involves the aggregation of small primary particles into larger disordered aggregates exhibiting a "brick-in-the-wall" structure. The actual crystallization occurs by the restructuring and coalescence of the "bricks" into a given calcium sulfate phase depending on the physicochemical conditions of the solution. Such a process yields a final imperfect mesocrystal, composed of smaller domains rather than a continuous single crystal structure.
These observations reveal that organic-free calcium sulfate mesocrystals grown by a particle mediated-pathway might preserve in the final crystal structure an “imprint” of their growth pathways. Indeed, by considering large anhydrite crystals from the famous Naica Mine we observed a suite of correlated self-similar void defects spanning multiple length-scales. These flaws, in the macroscopic crystal, stem from “seeds of imperfection” originating from an original particle-mediated growth. Hence, building a crystal could be viewed as Nature stacking blocks in a game of Tetris, whilst slowly forgetting the games core concept and failing to fill rows completely.
T2 - GeoMinKöln 2022
CY - Cologne, Germany
DA - 11.09.2022
KW - Anhydrite
KW - Mesocrystals
KW - Calcium sulfate
PY - 2022
AN - OPUS4-56277
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kellermeier, Matthias
A1 - Scheck, Johanna
A1 - Drechsler, Markus
A1 - Rosenberg, Rose
A1 - Stawski, Tomasz
A1 - Fernandez-Martinez, Alejandro
A1 - Gebauer, Denis
A1 - Van Driessche, Alexander E. S.
T1 - From Ions to Crystals: A Comprehensive View of the Non‐Classical Nucleation of Calcium Sulfate
N2 - After years of intensive research and numerous important observations, our understanding of the early stages of crystallization is still limited due to the complexity of the underlying processes and their elusive character. In the present work, we provide a detailed view on the nucleation of calcium sulfate mineralization – an abundant mineral with broad use in construction industry – in aqueous systems at ambient conditions. As experimental basis, a co‐titration procedure with potentiometric, turbidimetric and conductometric detection was developed, allowing solution speciation and the formation of crystallization precursors to be monitored quantitatively as the level of nominal (super)saturation gradually increases. The nature and spatiotemporal evolution of these precursors was further elucidated by time‐resolved small‐angle X‐ray scattering (SAXS) and analytical ultracentrifugation (AUC) experiments, complemented by cryogenic transmission electron microscopy (cryo‐TEM) as a direct imaging technique. The results reveal how ions associate into nanometric primary species, which subsequently aggregate and develop anisotropic order by intrinsic structural reorganization. Our observations challenge the common understanding of fundamental notions such as the nucleation barrier or the meaning of supersaturation, with broad implications for mineralization phenomena in general and the formation of calcium sulfate in geochemical settings and industrial applications in particular.
KW - Calcium sulfate
KW - Gypsum
KW - Nucleation
KW - Crystallisation
PY - 2024
DO - https://doi.org/10.1002/anie.202408429
SP - 1
EP - 12
PB - Wiley
AN - OPUS4-61585
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nag, Sayak
A1 - Emmerling, Franziska
A1 - Tothadi, Srinu
A1 - Bhattacharya, Biswajit
A1 - Ghosh, Soumyajit
T1 - Distinct photomechanical responses of two new 1,3-dimethylbarbituric acid derivative crystals
N2 - We demonstrate two distinct photomechanical responses (i.e. photomechanical bending and photosalient bursting) of two new 1,3-dimethylbarbituric acid derivative crystals based on tailoring their substituents and the modulation of their spacers.
KW - Crystal engineering
KW - Fexible crystals
PY - 2024
DO - https://doi.org/10.1039/D4CE00233D
SP - 1
EP - 12
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60141
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Dalgic, Mete-Sungur
T1 - Lösemittelfreie Probenpräparation zur Untersuchung von Polymerblends mittels MALDI-TOF MS
N2 - Die Probenpräparation ist ein wichtiger Schritt für die Qualität der Massenspektren in MALDI-TOF MS. Es werden Polymerproben, die lösungsmittelbasiert und lösungsmittelfrei präpariert worden sind, verglichen. Dabei werden die Intensitätsverhältnisse von ternären Mischungen von PEG-, PS- und PMMA-Polymeren beachtet.
T2 - 28. Kolloquium - Massenspektrometrische Techniken zur Untersuchung synthetischer Polymere
CY - Berlin, Germany
DA - 14.05.2024
KW - Polymere
KW - Massenspektrometrie
KW - Probenpräparation
PY - 2024
AN - OPUS4-60032
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Dalgic, Mete-Sungur
T1 - Discrimination effects in MALDI-MS of Ternary Polymer Mixtures
N2 - MALDI-TOF MS is a viable method to determine molecular weights of polymers. However, quantification using MALDI-TOF MS presents specific challenges due to intensity biases caused by instrumental and sample-specific parameters. In this presentation, the influence of molar masses on MALDI-TOF mass spectra is explored. The intensities of a ternary PMMA blend with different mixture ratios are depicted in contour plots.
T2 - SALSA Make and Measure 2022
CY - Berlin, Germany
DA - 15.09.2022
KW - MALDI-TOF MS
KW - Ternary polymer blends
KW - PMMA
PY - 2022
AN - OPUS4-62212
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Dalgic, Mete-Sungur
T1 - Einfluss der Konformation auf das Ionisationsverhalten in MALDI-TOF MS
N2 - MALDI-TOF Massenspektrometrie ist eine wichtige Methode zur Bestimmung von Molekulargewichten von Polymeren. Jedoch wird die quantitative Analyse von Polymeren durch verschiedene Faktoren erschwert. In dieser Präsentation wird unter anderem der Einfluss der molaren Massen auf die Massenspektren näher betrachtet. Dabei werden Konturplots von ternären PMMA- und PS-Mischungen gezeigt.
T2 - 27. Kolloquium - Massenspetrometrische von Polymeren
CY - Berlin, Germany
DA - 09.05.2023
KW - MALDI-TOF MS
KW - Ternäre Polymermischungen
KW - PMMA und PS
PY - 2023
AN - OPUS4-62214
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Fink, Friedrich
T1 - From Bench to Mini – Identification of technical Lignins with NIR
N2 - One of the most underutilized biological materials on our planet is lignin. It is the second most abundant biopolymer after cellulose. On an industrial scale, it mainly accumulates as a by-product in the pulp and paper industry. However, the utilization of technical lignins faces several challenges, including their complex and heterogeneous structure, which makes them difficult to process and limits their application. Additionally, the feedstock origin is a limiting factor. Classification according to the biomass origin is important for quality assurance and predictability of potential applications.
In this study, technical lignins were analyzed using a near-infrared (NIR) spectrometer. Different models were developed to classify these lignins, enabling rapid and reliable identification of their biomass sources, including softwoods, hardwoods, straw, and grasses. Various machine learning algorithms such as Support Vector Machines (SVM), Gaussian Process Classification (GPC), Gaussian Naive Bayes (GNB), and Decision Tree Classification (DTC) were compared based on different spectral preprocessing techniques and dimensionality reduction tools. The efficacy of the method was further tested using combined spectra from small handheld and compact spectrometers.
T2 - ESOPS 2024
CY - Berlin, Germany
DA - 09.09.2024
KW - NIR
KW - Lignin
PY - 2024
AN - OPUS4-62275
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Cakir, Cafer Tufan
T1 - Enhancing the Efficiency and Accessibility of Grazing Exit X-ray Absorption Spectroscopy for Corrosion and Layered Materials Analysis
N2 - In the field of materials science, there is a critical need for efficient and effective characterization techniques, especially in the investigation of corrosion processes of compositionally complex alloys (CCAs) or the analysis of layered structures. This talk presents an advanced approach that combines grazing-exit X-ray absorption near-edge structure spectroscopy (GE-XANES) with Bayesian optimization (BO) to significantly improve the efficiency of data acquisition while retaining the depth-resolved, element-specific analysis capabilities that are critical for studying these materials under ambient conditions. Using a non-destructive, scan-free GE-XANES setup coupled with a pnCCD detector and grazing exit X-ray fluorescence spectroscopy (GE-XRF) geometry, our method enables precise analysis at sub-micrometer depths without the need for high vacuum environments or extensive sample preparation. The integration of BO reduces experimental time by a factor of 50, overcoming the practical limitations of conventional GE-XANES and increasing its applicability in the study of surface catalysis and corrosion processes. We validate this optimized approach through comparative studies on a CrCoNi alloy and a reference layered sample, demonstrating its potential to revolutionize materials analysis by increasing both efficiency and accessibility.
T2 - Gesellschaft Deutscher Chemiker (GDCh)
CY - Clausthal-Zellerfeld, Germany
DA - 20.06.2024
KW - GEXRF
KW - GEXANE
KW - ML
PY - 2024
AN - OPUS4-61788
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stawski, Tomasz
A1 - Mishmastnehi, Moslem
T1 - What can we learn from traditional stucco masters?
N2 - Historical plaster formulations represent an underexplored avenue for understanding advanced materials engineering in premodern cultures. In this contribution, we investigate two distinct historical gypsum plasters, Gach-e Koshteh from 14th century Persia and Gesso Sottile from 15th century Italy, both of which were essential for architectural decoration and fine art. By replicating these methods in a laboratory setting, we explore how traditional artisans manipulated gypsum microstructures without any additives, to optimize surface and mechanical properties for specific artistic and functional outcomes.
Gach-e Koshteh employs a labor-intensive process involving kneading and mechanical treatment during hydration of bassanite to gypsum. This results in a plaster with a platelet-like crystal morphology and a pronounced alignment of the {010} faces, leading to a hydrophilic surface ideal for water-based decoration. These platelets form a compacted structure, reducing porosity while providing a smooth, workable surface for wall paintings. In contrast, Gesso Sottile relies on a slow recrystallization process in a large excess of water, yielding needle-like gypsum crystals that minimize hydrophilic surface area. This makes Sottile more suitable for oil-based panel paintings or as a substrate for gilding.
Our study applies a combination of wide-angle X-ray scattering (WAXS), atomic force microscopy (AFM), and scanning electron microscopy (SEM) to reveal the microstructural and surface properties of these historical plaster recipes. We demonstrate that the mechanical treatment in the Koshteh method leads to a denser, better-packed plaster with enhanced wettability due to the increased exposure of hydrophilic crystallographic planes. Meanwhile, the extended treatment time and high dilution in the Sottile recipe promote larger, loosely packed needle crystals that create a more hydrophobic surface.
These findings not only highlight the ingenuity of historical materials engineering but also provide valuable insights for modern restoration and preservation techniques. By understanding the role of microstructure in the durability and surface properties of historical plasters, we can improve the conservation of gypsum-based cultural heritage objects. This research also demonstrates the potential for sustainable materials engineering practices rooted in historical techniques, as these additive-free formulations exhibit long-lasting performance with minimal environmental impact.
T2 - Granada Muenster Discussion Meeting, GMDM2024
CY - Granada, Spain
DA - 27.11.2024
KW - Gypsum
PY - 2024
AN - OPUS4-62004
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dolai, Malay
A1 - Saha, Urmila
A1 - Goswami, Juli Nanda
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
A1 - Ifseisi, Ahmad A.
A1 - Biswas, Surajit
ED - Bhattacharya, Biswajit
T1 - Nickel(II)-mediated in situ complex formation with unexpected ligand transformations: crystal structures, DFT calculations, and catalytic activity in CO2 fixation reactions
N2 - Two transformed ligands, namely 1,3,5-triazapentadienato(imidoylamidinato) and N-(methoxy(pyrimidin-2-yl)(pyrimidine-2-carboxamido)methyl)pyrimidine-2-carboxamide, are reported here as the first products derived from 2-cyano pyridine/pyrimidine, respectively, under nickel metal mediation in the presence of hydroxylamine hydrochloride in situ. Two different nickel-coordinated complexes (1 and 2) were formed. Single crystal X-ray diffraction revealed that complex 1 is a mononuclear complex with tetra-coordinated square planar geometry, whereas complex 2 is a dinuclear complex with hexa-coordinated distorted octahedral geometry. The synthetic pathways of both transformed ligands are explained with the support of energy calculations of different states via density functional theory (DFT) calculations. The catalytic addition reactions of epoxides and carbon dioxide efficiently produce organic cyclic carbonates in the presence of complexes 1–2, attributed to the presence of Lewis acidic nickel and Lewis basic centers, such as free amine, imine, methoxy, or nitrogen in complexes 1 and 2. Under mild reaction conditions (1 atm CO2 pressure and 60 °C temperature), different types of epoxides (exocyclic, endocyclic, and aromatic epoxides) yield high levels of respective cyclic carbonates in the presence of both complexes 1–2 as catalysts, with tert-butylammonium bromide (TBAB) acting as a co-catalyst. The high turnover number (TON) and turnover frequency (TOF) of these catalytic reactions clearly indicate the efficacy of the two catalysts.
KW - Catalytic activity in CO2 fixation reactions DFT calculations
KW - Nickel(II)-complex
KW - In situ complex formation
KW - Crystal Structure
PY - 2025
DO - https://doi.org/10.1039/d4nj01801j
SN - 1369-9261
VL - 49
IS - 11
SP - 4451
EP - 4463
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-62782
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Reigl, Selina
A1 - Van Driessche, Alexander
A1 - Stawski, Tomasz
A1 - Koltzenburg, Sebastian
A1 - Kunz, Werner
A1 - Kellermeier, Matthias
T1 - Sustainable Pathways for the Synthesis of Calcium Sulfate Hemihydrate
N2 - Calcium sulfate, and especially its hemihydrate form (bassanite), is crucial in the construction industry, primarily used as a hydraulic binder in cements, mortars, and wallboards. Because of the rapid transformation of bassanite into thermodynamically stable gypsum (calcium sulfate dihydrate) upon contact with water, natural deposits are scarce, rendering it one of the most extensively produced inorganic materials worldwide. Currently, bassanite is derived from mined or waste gypsum through a thermal dehydration process, which is energy-intensive and costly. As sustainability has become a key target for industrial processes and products, a series of studies aiming to increase the energy efficiency and reduce the carbon footprint of bassanite production was published recently. Two primary approaches are pursued: conversion of gypsum and direct precipitation of bassanite from solution. In both cases, organic solvents, (specific) additives and/or elevated temperatures have been used to control the activity/availability of water in the reaction medium and thus direct phase selection towards bassanite. This review offers a comprehensive overview of alternative bassanite production methods, critically examining their benefits, potential downsides, and overall impact on
the sustainability of industrial-scale use.
KW - Calcium sulfate
KW - Gypsum
KW - Bassanite
KW - Recycling
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630657
DO - https://doi.org/10.1002/anie.202415161
SN - 1521-3773
SP - 1
EP - 20
PB - Wiley VHC-Verlag
AN - OPUS4-63065
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stawski, Tomasz M.
A1 - Salvalaglio, Matteo
A1 - Wallace, Adam F.
A1 - De Yoreo, James J.
T1 - The Birth of Minerals: From Single Step to Multiple Step Mechanisms
N2 - Mineral formation from ions in aqueous solutions begins with complex initial stages, where amorphous and liquid-like precursors play pivotal roles before crystalline growth occurs. Both classical and non-classical nucleation and growth theories, introduced in previous chapters, offer explanations, each with their own strengths and limitations, for the complex intermediate phases observed in experimental research. Analytical techniques play a critical role in detecting and characterizing precursor phases, offering valuable insights into nucleation and growth mechanisms across various temporal and spatial scales. Molecular dynamics and modelling provide in-depth perspectives on these phases, allowing for a closer examination of their nucleation and growth mechanisms at the molecular level, and revealing the intricate processes that govern their behaviour.
KW - Crystallisation
KW - Nucleation
KW - Synchrotron
KW - Thermodynamics
KW - Minerals
PY - 2025
DO - https://doi.org/10.2138/gselements.21.1.25
SN - 1811-5217
VL - 21
IS - 1
SP - 25
EP - 32
PB - Mineralogical Society of America
AN - OPUS4-62841
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stawski, Tomasz
T1 - Scattering is a powerful tool to follow nucleation and growth of minerals from solutions
N2 - In recent years, we have come to appreciate the astounding intricacy of the formation process of minerals from ions in aqueous solutions. The original ‘textbook’ image of these phenomena, stemming from the adaptation of classical nucleation and growth theories, has increased in complexity due to the discovery of a variety of precursor and intermediate species [e.g. 1], including solute clusters (e.g. prenucleation clusters, PNCs), liquid(-like) phases, as well as amorphous and nanocrystalline solids etc. In general, these precursor or intermediate species constitute different, often short-lived, points along the pathway from dissolved ions to the final solids (typically crystals in this context). In this regard synchrotron-based scattering (SAXS/WAXS/HEXD) appears to be the perfect tool to follow in situ and in a time-resolved manner the crystallization pathways because of the temporal and spatial length scales that can be directly accessed with these techniques.
Here, we show how we used scattering to probe the crystallization mechanisms of calcium sulfate. CaSO4 minerals (i.e. gypsum, anhydrite and bassanite) are widespread in natural and industrial environments. During the last several years, a number of studies have revealed indeed that nucleation in the CaSO4-H2O system is non-classical. Our SAXS data demonstrate that gypsum precipitation, involves formation and aggregation of sub-3 nm primary species. These species constitute building blocks of an amorphous precursor phase [2]. Further, we show how in situ high-energy X-ray diffraction experiments and molecular dynamics (MD) simulations can be combined to derive the atomic structure of the primary CaSO4 clusters seen at small-angles [3]. We fitted several plausible structures to the derived pair distribution functions and explored their dynamic properties using unbiased MD simulations based on polarizable force fields. Finally, based on combined SAXS/WAXS, broad-q-range measurements, we show that the process of formation of bassanite, a less hydrated form of CaSO4, is very similar to the formation of gypsum: it also involves the aggregation of small primary species into larger disordered aggregates [4].
Based on these recent insights we formulated a tentative general model for calcium sulfate precipitation from solution. This model involves primary species that are formed through the assembly of multiple Ca2+ and SO42- ions into nanoclusters. These nanoclusters assemble into poorly ordered (i.e. amorphous) hydrated aggregates, which in turn undergo ordering into coherent crystalline units of either gypsum or bassanite (and possibly anhydrite). Determination of the structure and (meta)stability of the primary species is important from both a fundamental, e.g. establishing a general non-classical nucleation model, and applied perspective; e.g. allow for an improved design of additives for greater control of the nucleation pathway.
T2 - Annual Meeting of German Crystallographic Society (29. Jahrestagung der Deutschen Gesellschaft für Kristallographie - DGK
CY - Online meeting
DA - 15.03.2021
KW - Scattering
KW - Calcium sulfate
KW - SAXS/WAXS
PY - 2021
AN - OPUS4-53619
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yusenko, Kirill
A1 - Khandarkhaeva, S.
A1 - Bykov, M.
A1 - Fedotenko, T.
A1 - Hanfland, M.
A1 - Sukhikh, A.
A1 - Gromilov, S.
A1 - Dubrovinsky, L.
T1 - Face-centered cubic refractory alloys prepared from single-source precursors
N2 - Three binary fcc-structured alloys (fcc–Ir0.50Pt0.50, fcc Rh0.66Pt0.33 and fcc–Rh0.50Pd0.50) were 14 prepared from [Ir(NH3)5Cl][PtCl6], [Ir(NH3)5Cl][PtBr6], [Rh(NH3)5Cl]2[PtCl6]Cl2 and 15 [Rh(NH3)5Cl][PdCl4]·H2O, respectively, as single-source precursors. All alloys were prepared by 16 thermal decomposition in gaseous hydrogen flow below 800 °C. Fcc–Ir0.50Pt0.50 and fcc–Rh0.50Pd0.50 17 correspond to miscibility gaps on binary metallic phase diagrams and can be considered as 18 metastable alloys. Detailed comparison of [Ir(NH3)5Cl][PtCl6] and [Ir(NH3)5Cl][PtBr6] crystal 19 structures suggests that two isoformular salts are not isostructural. In [Ir(NH3)5Cl][PtBr6], specific 20 Br…Br interactions are responsible for crystal structure arrangement. Room temperature 21 compressibility of fcc–Ir0.50Pt0.50, fcc–Rh0.66Pt0.33 and fcc–Rh0.50Pd0.50 has been investigated up to 50 GPa 22 in diamond anvil cells. All investigated fcc-structured binary alloys are stable under compression. 23 Atomic volumes and bulk moduli show good agreement with ideal solutions model. For fcc–24 Ir0.50Pt0.50, V0/Z = 14.597(6) Å3·atom-1, B0 = 321(6) GPa, B0' = 6(1); for fcc–Rh0.66Pt0.33, V0/Z = 14.211(3) 25 Å3·atom-1, B0 =259(1) GPa, B0' = 6.66(9); for fcc–Rh0.50Pd0.50, V0/Z = 14.18(2) Å3·atom-1, B0 =223(4) GPa, 26 B0' = 5.0(3).
KW - High-pressure
KW - Refractory alloys
KW - Platinum group metals
KW - Single-source precursors
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508176
DO - https://doi.org/10.3390/ma13061418
VL - 13
IS - 6
SP - 1418
PB - MDPI
CY - Basel
AN - OPUS4-50817
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yusenko, Kirill
A1 - Sukhikh, A.
A1 - Kraus, Werner
A1 - Gromilov, S.
T1 - Synthesis and Crystal Chemistry of Octahedral Rhodium(III) Chloroamines
N2 - Rhodium(III) octahedral complexes with amine and chloride ligands are the most common starting compounds for preparing catalytically active rhodium(I) and rhodium(III) species. Despite intensive study during the last 100 years, synthesis and crystal structures of rhodium(III) complexes were described only briefly. Some [RhClx(NH3)6-x] compounds are still unknown. In this study, available information about synthetic protocols and the crystal structures of possible [RhClx(NH3)6−x] octahedral species are summarized and critically analyzed. Unknown crystal structuresof(NH4)2[Rh(NH3)Cl5],trans–[Rh(NH3)4Cl2]Cl·H2O,andcis–[Rh(NH3)4Cl2]Clarereported based on high quality single crystal X-ray diffraction data. The crystal structure of [Rh(NH3)5Cl]Cl2 was redetermined. All available crystal structures with octahedral complexes [RhClx(NH3)6-x] were analyzed in terms of their packings and pseudo-translational sublattices. Pseudo-translation lattices suggest face-centered cubic and hexagonal closed-packed sub-cells, where Rh atoms occupy nearly ideal lattices.
KW - Pseudo-translationalsublattices
KW - Rhodiumcomplexes
KW - Ligandsubstitution
KW - Crystalstructure
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508194
DO - https://doi.org/10.3390/molecules25040768
VL - 25
IS - 4
SP - 768
PB - MDPI
CY - Basel
AN - OPUS4-50819
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yusenko, Kirill
A1 - Domonov, D.
A1 - Pechenyuk, S.
A1 - Belyevskii, A.
T1 - Formation of Nanostructured Carbon from [Ni(NH3)6]3[Fe(CN)6]2
N2 - The products of thermal decomposition in an argon atmosphere of [Ni(NH3)6]3[Fe(CN)6]2 as a precursor has been studied. Decomposition products were studied up to 800◦C. Above 600◦C, all coordination bonds in the residues are broken with a formation of Ni3Fe, Fe, and free carbon with a small admixture of nitrogen. Elementary carbon can be easily separated from metals by treatment with a water solution of hydrochloric acid. Only carbon is responsible for the specific surface of the composite products. The released carbon has a high degree of graphitization and begins to oxidize in air above 500°C and is completely oxidized above 700°C.
KW - Carbon materials
KW - Double complex compound
KW - Thermal decomposition
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508188
DO - https://doi.org/10.3390/nano10020389
VL - 10
IS - 2
SP - 389
PB - MDPI
CY - Basel
AN - OPUS4-50818
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stawski, Tomasz
T1 - Scattering is a powerful tool to follow nucleation and growth of minerals from solutions
N2 - In recent years, we have come to appreciate the astounding intricacy of the processes leading to the formation of minerals from ions in aqueous solutions. The original, and rather naive, ‘textbook’ image of these phenomena, stemming from the adaptation of classical nucleation and growth theories, has increased in complexity due to the discovery of a variety of precursor and intermediate species. These include solute clusters (e.g. prenucleation clusters, PNCs), liquid(-like) phases, as well as amorphous and nanocrystalline solids etc.. Does it, however, mean that all the minerals grow through intermediate phases, following a non-classical pathway?
In general, the precursor or intermediate species constitute different, often short-lived, points along the pathway from dissolved ions to the final solids (typically crystals in this context). In this regard synchrotron-based scattering (SAXS/WAXS/total scattering) appears to be the perfect tool to follow in situ and in a time-resolved manner the crystallization pathway because of the temporal and spatial length scales that can be directly accessed with these techniques. In this presentation we show how we used scattering to probe the crystallisation mechanisms of calcium sulfate, This system contains minerals that are widespread in diverse natural environments, but they are also important in various industrial settings. Our data demonstrate that calcium sulfate precipitation involves formation and aggregation of sub-3 nm anisotropic primary species. The actual crystallisation and formation of imperfect single crystals of calcium sulfate phases, takes place from the inside of the in itial aggregates. Hence, calcium sulfate follows a non-classical pathway.
T2 - X-ray Powder Diffraction at DESY - new opportunities for research and industry
CY - Online meeting
DA - 22.06.2020
KW - Nucleation
KW - Calcium sulfate
KW - Diffraction
KW - Scattering
KW - Synchrotron
KW - SAXS/WAXS
PY - 2020
AN - OPUS4-50943
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mishmastnehi, Moslem
A1 - Stawski, Tomasz M.
A1 - Eftekhari, Negar
A1 - Schneider, Kathrin P.
A1 - Vaccaro, Carmela
A1 - Aghajani, Iman
A1 - Grbanovic, Ana Marija
A1 - Korn, Lorenz
T1 - Unveiling the craftsmanship and knowledge behind iranian stuccoes (11th–14th centuries): New insights from an archaeometric perspective
N2 - Gypsum-based stucco decorations of 47 monuments in Iran, from the Seljuq to the Ilkhanid period (11th-14th centuries), were studied by multimodal analytical methods, including X-ray diffraction, X-ray fluorescence, scanning electron microscopy and image analysis to evaluate their composition properties. The assessment of results shows that stucco masters in those periods exerted control over the setting process of the gypsum-paste and its microstructure by adjusting water-to-plaster ratio, fine-clay addition, and by means of mechanical processing. Furthermore, the presence of anhydrite in the composition of stucco decorations located in the hot-desert climate of Iran provides evidence for the probability of gypsum-anhydrite transition, which has technical and preservation consequences for this less-investigated type of cultural materials.
KW - Gypsum
KW - Diffraction
KW - Anhydrite
KW - Calcium sulfate
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628406
DO - https://doi.org/10.1016/j.jas.2025.106199
SN - 1095-9238
VL - 177
SP - 1
EP - 13
PB - Elsevier B.V.
AN - OPUS4-62840
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yusenko, Kirill
A1 - Petrushina, M.
A1 - Dedova, E.
A1 - Portnaygin, A.
A1 - Papynov, E.
A1 - Filatov, E.
A1 - Korenev, S.
A1 - Gubanov, A.
T1 - Effect of temperature and pressure on mixed oxide solid solutions
N2 - A hydrothermal synthesis of ZrW2-xMoxO8 (0 ≤ x ≤ 2) from the corresponding precursors is reported in this paper. High-temperature and high-pressure data are presented for the sample with x = 1.6. An increase in temperature initiates the phase transition from tetragonal precursor to orthorhombic-ZrW2-xMoxO8 (x = 1.6) with the subsequent formation of cubic and trigonal phases. The thermolysis parameter of the disordered cubic ZrW2-xMoxO8 (x = 1.6) phase is 803 K, and the coefficient of thermal expansion is α = -4.6∙10–6 K−1. Data on ZrW2-xMoxO8 (x = 1.6) structure as a function of pressure are obtained for the first time. Pressureinduced changes from cubic to orthorhombic ZrW2-xMoxO8 (x = 1.6) phase at 1.38 GPa are observed. The sample amorphization is irreversible during decompression.
KW - Phase transition
KW - High-pressure
KW - Complex oxides
PY - 2020
DO - https://doi.org/10.1016/j.inoche.2020.107965
VL - 117
SP - 107965
PB - Elsevier B.V.
AN - OPUS4-50821
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stawski, Tomasz
A1 - Besselink, R.
A1 - Chatzipanagis, K.
A1 - Hövelmann, J.
A1 - Benning, L. G.
A1 - Van Driessche, E. S.
T1 - Nucleation Pathway of Calcium Sulfate Hemihydrate (Bassanite) from Solution: Implications for Calcium Sulfates on Mars
N2 - CaSO4 minerals (i.e., gypsum, anhydrite, and bassanite) are widespread in natural and industrial environments. During the last several years, a number of studies have revealed that nucleation in the CaSO4–H2O system is nonclassical, where the formation of crystalline phases involves several steps. Based on these recent insights, we have formulated a tentative general model for calcium sulfate precipitation from solution. This model involves primary species that are formed through the assembly of multiple Ca2+ and SO42– ions into nanoclusters. These nanoclusters assemble into poorly ordered (i.e., amorphous) hydrated aggregates, which in turn undergo ordering into coherent crystalline units. The thermodynamic (meta)stability of any of the three CaSO4 phases is regulated by temperature, pressure, and ionic strength, with gypsum being the stable form at low temperatures and low-to-medium ionic strengths and anhydrite being the stable phase at high temperatures and at lower temperature for high salinities. Bassanite is metastable across the entire phase diagram but readily forms as the primary phase at high ionic strengths across a wide range of temperatures and can persist up to several months. Although the physicochemical conditions leading to bassanite formation in aqueous systems are relatively well established, nanoscale insights into the nucleation mechanisms and pathways are still lacking. To fill this gap and to further improve our general model for calcium sulfate precipitation, we conducted in situ scattering measurements at small-angle X-ray scattering and wide-angle X-ray scattering and complemented these with in situ Raman spectroscopic characterization. Based on these experiments, we show that the process of formation of bassanite from aqueous solutions is very similar to the formation of gypsum: it involves the aggregation of small primary species into larger disordered aggregates, only from which the crystalline phase develops. These data thus confirm our general model of CaSO4 nucleation and provide clues to explain the abundant occurrence of bassanite on the surface of Mars (and not on the surface of Earth).
KW - Gypsum' SAXS
KW - Calcium sulfate
KW - Bassanite
KW - Nucleation
PY - 2020
DO - https://doi.org/10.1021/acs.jpcc.0c01041
VL - 124
IS - 15
SP - 8411
EP - 8422
PB - American Chemical Society
AN - OPUS4-50849
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Besselink, R.
A1 - Stawski, Tomasz
A1 - Freeman, H. M.
A1 - Hovelmann, J.
A1 - Tobler, D. J.
A1 - Benning, L. G.
T1 - Mechanism of Saponite Crystallization from a Rapidly Formed Amorphous Intermediate
N2 - Clays are crucial mineral phases in Earth’s weathering engine, but we do not know how they form in surface environments under (near-)ambient pressures and temperatures. Most synthesis routes, attempting to give insights into the plausible mechanisms, rely on hydrothermal conditions, yet many geological studies showed that clays may actually form at moderate temperatures (<100 °C) in most terrestrial settings. Here, we combined high-energy X-ray diffraction, infrared spectroscopy, and transmission electron microscopy to derive the mechanistic pathways of the low-temperature (25–95 °C) crystallization of a synthetic Mg-clay, saponite. Our results reveal that saponite crystallizes via a two stage process: (1) a rapid (several minutes) coprecipitation where ∼20% of the available magnesium becomes incorporated into an aluminosilicate network, followed by (2) a much slower crystallization mechanism (several hours to days) where the remaining magnesium becomes gradually incorporated into the growing saponite sheet structure.
KW - Saponite
KW - FTIR
KW - PDF
KW - Diffraction
PY - 2020
DO - https://doi.org/10.1021/acs.cgd.0c00151
VL - 20
IS - 5
SP - 3365
EP - 3373
PB - American Chemical Society
AN - OPUS4-50917
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yusenko, Kirill
A1 - Zvereva, V.
A1 - Martynova, S.
A1 - Asanov, I.
A1 - La Fontaine, C.
A1 - Roudenko, O.
A1 - Gubanov, A.
A1 - Plyusnin, P.
A1 - Korenev, S.
A1 - Asanova, T.
T1 - Insight of the thermal decomposition of ammonium hexahalogenoiridates(IV) and hexachloroiridate(III)
N2 - Thermal decomposition of (NH4)3[IrCl6]·H2O, (NH4)2[IrCl6] and (NH4)2[IrBr6] in reductive and inert atmospheres has been investigated in situ using quick-EXAFS and temperature-resolved powder X-ray diffraction. For the first time, (NH4)2[Ir(NH3)Cl5] and (NH4)2[Ir(NH3)Br5] have been proven as intermediates of thermal decomposition of (NH4)3[IrCl6]·H2O, (NH4)2[IrCl6] and (NH4)2[IrBr6]. Thermal degradation of (NH4)2[IrCl6] and (NH4)2[IrBr6] is a more complex process as suggested previously and includes simultaneous formation of (NH4)2[Ir(NH3)Cl5] and (NH4)2[Ir(NH3)Br5] intermediates mixed with metallic iridium. In the inert atmosphere, complexes (NH4)[Ir(NH3)2Cl4] and (NH4)[Ir(NH3)2Br4] as well as [Ir(NH3)3Br3] were proposed as possible intermediates before formation of metallic iridium particles
KW - Thermal decomposition
KW - Iridium compounds
KW - EXAFS
KW - In situ PXRD
PY - 2020
DO - https://doi.org/10.1039/D0CP02743J
VL - 22
IS - 40
SP - 22923
EP - 22934
AN - OPUS4-51224
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stolar, Tomislav
T1 - Sustainable mechanochemical reaction engineering: from molecular mechanisms to scalable technology
N2 - In this talk, I will present about our quest to fundamentally understand mechanochemical reactions by in situ monitoring studies. Another of our interest is scaling up mechanochemistry. For example, we are now working on developing mechanochemical technology to enable a circular economy of plastics.
T2 - Korea-Germany Symposium on Mechanochemistry
CY - Jeonju, South Korea
DA - 02.10.2024
KW - Mechanochemistry
KW - Plastic recycling
KW - Circular economy
PY - 2024
AN - OPUS4-62110
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stolar, Tomislav
T1 - Mechanochemistry: fundamentals to application
N2 - In the first part, I will talk about the role of mechanochemistry in prebiotic chemistry. For example, prebiotically plausible pathways to peptides from inactivated amino acids are unclear as most oligomerization approaches rely on thermodynamically disfavored reactions in solution. I will show how a combination of mineral surfaces and mechanochemical activation enables the oligomerization of amino acids to oligopeptides (Figure 1). In the second part, I will show how fundamental studies inspired to use mechanochemistry for the sustainable synthesis of commercially relevant compounds, in line with the United Nations Sustainable Development Goals.2 We developed a solvent-free thermo-mechanochemical approach for the direct coupling of carboxylic acids and amines, which avoids activators and additives. We applied our methodology for the quantitative synthesis of the active pharmaceutical ingredient moclobemide (Figure 2).
T2 - Solutions in Chemistry Conference 2024
CY - Sveti Martin na Muri, Croatia
DA - 15.11.2024
KW - Mechanochemistry
KW - Plastic recycling
KW - Circular economy
PY - 2024
AN - OPUS4-62111
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ryll, Tom William
T1 - Applied and Technical Mineralogy:� high-throughput automated platform for in-situ monitoring of CaSO4 formation
N2 - In this project we investigate nucleation pathways by utilizing synchrotron-XRD and running a case-study on calcium sulfate and its polymorphs. To accomplish this, we developed a modular automation setup for reactions in solution to run synthesis and control reaction conditions. So far we successfully characterized the recycling process of gypsum (CaSO4*2H2O) and are now investigating the formation of anhydrite (CaSO4*0H2O) as well as possible applications for the automation setup and analysis.
T2 - Geo4Göttingen 2025
CY - Göttingen, Germany
DA - 14.09.2025
KW - Recycling
KW - Gypsum
KW - Synchrotron-X-ray-diffraction
KW - Raman-spectroscopy
KW - Automation
PY - 2025
AN - OPUS4-64139
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stolar, Tomislav
T1 - Thermo mechanochemistry: merging heat and force for discovering new chemical transformations
N2 - Mechanochemistry is a hot topic in chemistry, and the number of researchers from academia and industry joining the field is growing. Mechanical action drives chemical reactions forward independently of the solubility of reactants and drastically minimises solvent usage and waste production. Mechanochemistry also provides other advantages, such as faster reaction times, higher yields, altered selectivity, and access to products not obtainable by other methods. Furthermore, recent innovations in mechanochemistry enable conducting chemical reactions by combining force and heat in approach called thermo-mechanochemistry [1]. These conditions typically overcome high activation energies and access products not obtainable by mechanochemistry at ambient temperature conditions. In this talk, I will give an overview to this emerging topic and to our discoveries by thermo-mechanochemistry that include prebiotic peptide bond formation [2], synthesis of amide-based active pharmaceutical ingredient [3], condensation of diamondoid derivatives [4], and manipulation of polymorphic transition temperatures in organic molecular crystals [5].
T2 - Department Seminar at Newcastle University
CY - Newcastle, UK
DA - 15.09.2023
KW - Mechanochemistry
PY - 2023
AN - OPUS4-62104
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stolar, Tomislav
T1 - Sustainable mechanochemical reaction engineering: from molecular mechanisms to scalable technology
N2 - In this talk, I will present about our quest to fundamentally understand mechanochemical reactions by in situ monitoring studies. Another of our interest is scaling up mechanochemistry. For example, we are now working on developing mechanochemical technology to enable a circular economy of plastics.
T2 - Hokkaido International Workshop on Mechanochemistry
CY - Hokkaido, Japan
DA - 29.09.2024
KW - Mechanochemistry
KW - Plastic recycling
KW - Circular economy
PY - 2024
AN - OPUS4-62109
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stolar, Tomislav
T1 - Grinding away plastic waste: enabling the circular economy of plastics
N2 - Single-use plastics are causing plastic pollution, and less than 10% of plastic waste gets recycled globally. Most of it ends up in landfills or is being incinerated in a highly unsustainable manner. Plastic waste in the environment endangers ecosystems, and microplastics in babies raise alarming health concerns. Hence, one of the global priorities is circular economy for plastics which does not further exploit fossil fuel feedstocks. However, current technologies like mechanical recycling are inadequate, and innovative ones such as chemical recycling, i.e., converting plastics back to the starting monomers, are essential. For example, we can use the recycled monomers to make new plastics in a circular manner or upcycle them to other value-added functional materials. Here, I will present a sustainable technology we developed for the chemical recycling of polyethylene terephthalate (PET). PET represents 10% of global plastic production and dominates in plastic packaging. The technology relies on mechanochemistry (grinding) which uses mechanical action for the chemical breakdown of plastic polymers in an environmentally friendly way. The next step in our research is to use life cycle and techno-economic assessment to validate the sustainability and commercial viability of our technology with the goal of transferring it to real-world industrial application.
T2 - Berlin PostDoc Day 2023
CY - Berlin, Germany
DA - 02.11.2023
KW - Mechanochemistry
KW - Plastic recycling
KW - Circular economy
PY - 2023
AN - OPUS4-62103
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stolar, Tomislav
T1 - Breaking the wall of circular plastics economy
N2 - Traditional mechanical recycling cannot process most plastic waste streams and most of the plastic waste currently goes to landfills or incineration. Chemical recycling is a promising technology to mitigate this but is hindered by high costs (due to high process temperatures and production of solvent waste). We developed a cost-efficient technology for chemical recycling of plastic waste that reduces greenhouse gas emissions and minimizes energy consumption. It is based on solvent-free mechanochemistry for depolymerization of plastic polymers at ambient conditions.
T2 - Falling Walls Lab Berlin-Adlershof
CY - Berlin, Germany
DA - 21.09.2023
KW - Mechanochemistry
KW - Recycling
KW - Circular economy
PY - 2023
AN - OPUS4-62101
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stolar, Tomislav
T1 - Breaking the wall of circular plastics economy
N2 - Traditional mechanical recycling cannot process most plastic waste streams and most of the plastic waste currently goes to landfills or incineration. Chemical recycling is a promising technology to mitigate this but is hindered by high costs (due to high process temperatures and production of solvent waste). We developed a cost-efficient technology for chemical recycling of plastic waste that reduces greenhouse gas emissions and minimizes energy consumption. It is based on solvent-free mechanochemistry for depolymerization of plastic polymers at ambient conditions.
T2 - 2023 Falling Walls Science Summit
CY - Berlin, Germany
DA - 07.11.2023
KW - Mechanochemistry
KW - Plastic recycling
KW - Circular economy
PY - 2023
AN - OPUS4-62102
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mishmastnehi, M.
A1 - Van Driessche, A.
A1 - Smales, Glen Jacob
A1 - Moya, A.
A1 - Stawski, Tomasz
T1 - Advanced materials engineering in historical gypsum plaster formulations
N2 - We show how historical gypsum plaster preparation methods affect the microstructure and the wettability properties of the final stucco materials. We reproduced a traditional Persian recipe (Gach-e Koshteh, ~14th century AD), which involves a continuous mechanical treatment during plaster hydration. These samples were compared with a laboratory-replicated historical recipe from Renaissance Italy (Gesso Sottile, ~15th century AD) and contemporary low-strength plaster. The Koshteh recipe induces the formation of gypsum platelets, which exhibit preferential orientation in the plaster bulk. In contrast,
the Italian and low-strength plasters comprise a typical needle-like morphology of gypsum crystals. The platelets in Koshteh expose the more hydrophilic {010} face of gypsum in a much more pronounced manner than needles. Consequently, the Iranian plaster displays enhanced wettability, enabling its direct use for water-based decoration purposes, or as a fine finishing thin layer, without the need of mixing it with a binder material.
Contrary, in Sottile, gypsum crystals are left to equilibrate in large excess of water, which promotes the growth of long needles at the expense of smaller crystals. Typically, such needles are several times longer than those found in a control regular plaster. For this
crystal habit, the total surface of hydrophilic faces is minimized. Consequently, such plaster layers tend to repel water, which can then be used, e.g., as a substrate for oilbased panel paintings. These findings highlight the development of advanced functional materials, by tuning their microtexture, already during the premodern era.
KW - Gypsum
KW - Calcium sulfate
KW - Diffraction
KW - Force microscopy
PY - 2023
DO - https://doi.org/10.1073/pnas.2208836120
VL - 120
IS - 7
SP - 1
EP - 9
PB - National Academy of Sciences of the USA
AN - OPUS4-57219
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ryll, Tom William
T1 - Researching automation of gypsum recycling
N2 - This poster illustrates first successful experiments of recycling gypsum in hypersaline solutions with quantification via Raman-spectroscopy. To furhter enhancements include an automation setup, that was developed to gain in-situ measurements and open a pathway for batch-conversions and upscaling.
T2 - BESSY@HZB User Meeting
CY - Berlin, Germany
DA - 12.12.2024
KW - Recycling
KW - Gypsum
KW - Raman-spectroscopy
KW - Automation
PY - 2024
AN - OPUS4-62292
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhuang, Yiling
A1 - Haderlein, Stefan B.
A1 - Lutze, Holger V.
A1 - Sun, Chen
A1 - Fink, Friedrich
A1 - Paul, Andrea
A1 - Spahr, Stephanie
T1 - Persulfate activation by biochar for trace organic contaminant removal from urban stormwater
N2 - Persistent and mobile trace organic contaminants (TrOCs) in urban stormwater are difficult to remove through sedimentation- or sorption-based treatment and pose a risk to aquatic ecosystems and drinking water supplies. We demonstrate that the chemical oxidant peroxydisulfate (PDS) can be activated by shrimp shell biochar at pH 7 to form reactive species that selectively react with widespread stormwater contaminants. Of 11 TrOCs tested, oxidative transformation was observed for 1,3-diphenylguanidine, 2-hydroxybenzothiazole, 1H-benzotriazole, 5-methyl-benzotriazole, and diuron during water treatment with biochar and PDS. Laboratory batch experiments conducted with street runoff and a synthetic water showed that the water matrix, containing up to 7.5 mg L-1 dissolved organic carbon and 100 mM chloride, had a minor effect on the formation of reactive species and contaminant transformation. Using a set of scavengers and probe compounds, we provide evidence for singlet oxygen (1O2) as the predominant reactive species in the biochar/PDS system, which is in agreement with the selectivity of the process to oxidize electron-rich organic contaminants. The results of our study inform new strategies for stormwater treatment using heterogeneous oxidation processes for the abatement of persistent and mobile organic contaminants.
KW - Stormwater treatment
KW - Oxidation processes
KW - Pyrogenic carbon
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637952
DO - https://doi.org/10.1016/j.watres.2025.123921
SN - 0043-1354
VL - 284
SP - 1
EP - 8
PB - Elsevier Ltd.
AN - OPUS4-63795
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Wagner, Jan
T1 - This is the Way: An Evidence Based Route to Phytic-acid-based Flame Retardant Poly(lactide acid)
N2 - Main message: This study provides an evidence-based route to flame retard poly (lactide acid) (PLA) with phytic acid (Phyt)-based flame retardants (FR). Phyt was prepared with lignin (Lig) and expandable graphite (EG). Three amine salts (arginine (Arg), piperazine (Pip), melamine (Mel)) were also synthesized with Phyt. Findings include UL 94 V0 classification, limited oxygen index (LOI) = 43.7 vol% and reduced total heat released (THR), while molecular weight (MW) was not affected. Combinations lead to the most effective FR.
Introduction: As demand for biobased polymers increases, biobased FRs remain scarce in the market. With 28 wt.% P, Phyt is promising to be a biobased FR, but Phyt efficiency as a FR needs to be improved. [1] Furthermore, as a strong acid, it esterifies and hydrolysis PLAs backbone. With the combinations proposed in this study, processability and MW in PLA compounds were untouched, while FR performance of Phyt was enhanced.
Experimental: Compounds analyzed in this study were: PLA, PLA Lig, PLA EG, PLA PhytLig, PLA PhytEG, PLA Mel, PLA PhytArg, PLA PhytPip, PLA PhytMel, PLA PhytMel Lig and PLA PhytMel EG. Addition of Phyt based FR was 16.7 wt.%, Lig and EG 10wt.%. Compounds were processed with twin screw extrusion, injection molding and hot press. Analysis was done with size exclusion tomography, differential scanning calorimetry (DSC), tensile strength, cone calorimeter, UL 94, LOI and thermogravimetry analysis (TGA) combined with Fourier transformation infrared spectroscopy (FTIR). Residues were analyzed with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX).
Results and Discussion: To synthesize the FR, Lig and Phyt (solved in water) were mixed and dried. A solid material formed, which was grinded and then compounded with PLA. The same was done with EG. Phyt + Arg/Pip/Mel FR materials were each titrated to a pH of ~4.5, since this pH is known to be least harmful for the PLA backbone. For PhytMel a salt precipitated. PhytPip and PhytArg were dried and a resin-like structure was obtained, which was grinded to a powder. The molar mass distribution of PLA PhytArg (10,000 g/mol – 600,000 g/mol) is similar to PLAs ranging from 15,000 g/mol – 600,000 g/mol. MW distribution from highest to lowest was PLA > PLA PhytArg > PLA PhytMel > PLA PhytMel EG > PLA PhytMel Lig > PLA PhytEG > PLA PhytLig > PLA PhytPip. The reaction between Phyt and Arg/Mel prevents MW decomposition of PLA through a reaction of P acid and NH2 groups. Tensile strength declined to 35.9 MPA for PLA PhytMel and 32.1 MPA for PLA PhytArg, compared to 51.4 MPA for PLA. DSC analysis revealed TG was not affected for the FR compounds: Phyt Lig/EG/Arg/Mel, compared to PLA. PLA PhytMel crystallinity 𝐾∆𝐻𝑐𝑐𝑐𝑐 was 30%, PLA PhytArg crystallinity was 50%, compared to PLA 𝐾∆𝐻𝑐𝑐 was 46%. Melting peaks were not affected in PLA Phyt Arg/Mel.
Flammability investigations lead to results of LOI 25.8 vol%/ UL 94 V2 classification in PLA, PLA PhytArg LOI 43.7 vol%/ UL 94 V2, due to strong dripping as a cooling mode of action. [2] PLA PhytMel burned with intumescent char and LOI 38.2 vol%/ UL 94 V2 was measured. Due to strong melt dripping, PLA PhytPip reached UL 94 V0. TGA revealed increased residue for all FR compounds. When materials were combined in PLA PhytMel EG residue was maximized to 19.9 wt.% (600°C, 𝑁𝑁2 atmosphere). FTIR analysis revealed PO and PH stretching vibrations, indicating radical scavenging. Cone calorimeter investigations of PLA, PLA PhytPip and PLA PhytArg lead to a steep incline in HRR to peak heat release rate (pHRR). Values are provided in Table 1. PLA PhytMel containing compounds exhibited prolonged burning and protective layer. PLA PhytLig, PLA PhytEG, PLA Mel (pHRR >1000) were investigated but proved inferior to PLA PhytMel, PLA PhytMel Lig and PLA PhytMel EG. THR was reduced in all Phyt compounds. Intumescence was observed in all compounds except for PLA Lig, PLA PhytLig and PLA PhytMel Lig. PLA PhytMel EG proved as the most effective compound in fire testing with a firm, coherent and intumescent char structure. This study provides an understanding of Phyt as a FR. It systematically improves Phyts effectiveness and processability in PLA. This evidence
T2 - 20th European Meeting on Fire Retardant Polymeric Materials (FRPM2025)
CY - Madrid, Spain
DA - 03.06.2025
KW - Polylactide acid
KW - Intumescence
KW - Phosphorous flame retardant
KW - Phytic acid
PY - 2025
AN - OPUS4-63395
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - RPRT
A1 - Maiwald, Michael
A1 - Villajos Collado, José Antonio
T1 - Metal-organic framework compounds as hydrogen storage materials to enhance the safety, capacity, and efficiency of hydrogen refueling stations
N2 - Gas adsorption is based on physical properties between gases and solid materials, enriching the surface with packed gas molecules with a higher density than in the bulk phase. For using this mechanism as a gas storage strategy, highly porous materials are necessary since large surfaces in small volumes can provide the storage system with a higher density than the gas phase. In the case of hydrogen gas, the interaction forces with solid surfaces are generally low at room temperature but can increase considerably at low operating temperatures. As a counterpart, the storage pressure is considerably lower than that necessary by traditional gas compression.
Amongst ultra-porous adsorbent materials for hydrogen cryoadsorption, metal-organic frameworks (MOFs) are a group of remarkable solids made from metallic nodes linked by organic molecules exhibiting a wide variety of composition, geometry, porous properties, and chemical functionality. The scientific community focused in the last years on enhancing both the specific area of materials and the interaction energy to extend the storage properties of cryoadsorption to ambient-temperature and use it as hydrogen storage mechanisms in vehicles. However, the found difficulty in achieving ultra-porous structures with high-enough interaction energies decreased this research interest in the last years.
However, for a stationary application like hydrogen refueling stations, where space and weight are not such limits as in vehicles, cryoadsorption can still be considered a feasible candidate for hydrogen storage. Cryoadsorption is the only fast and fully reversible approach to store hydrogen at similar density values as compressed gas. Cryogenic operation is a technological challenge, but first, liquid nitrogen is cheap, and second, it is less energy-demanding than hydrogen liquefaction, which is indeed considered as feasible for transportation and storage. Cryoadsorption involves lower pressure
than compressed gas, increasing safety in the storage facilities, but additional research on the construction materials properties is necessary to better understand their behavior in contact with hydrogen at cryogenic temperatures. However, the knowledge of all these mechanisms is important to identify the improvement opportunities based on, probably, the interphase between different solutions.
To achieve the set project goals, this internal research report describes the work packages realised within the framework of the project.
KW - Metal-organic frameworks (MOFs)
KW - Hydrogen Storage
KW - Reversible Hydrogen Storage
KW - Hydrogen Fuelling Stations
KW - Croyo-starage
KW - High-pressure volumetric analyzer (HPVA)
PY - 2021
SP - 1
EP - 48
CY - Berlin
AN - OPUS4-53582
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mohring, Wencke
A1 - Karafiludis, Stephanos
A1 - Manzoni, Anna Maria
A1 - Laplanche, G.
A1 - Schneider, M.
A1 - Stephan-Scherb, Christiane
T1 - High-Temperature Corrosion of High- and Medium-Entropy Alloys CrMnFeCoNi and CrCoNi Exposed to a Multi-Oxidant Atmosphere H2O–O2–SO2
N2 - AbstractThe high-temperature corrosion behaviors of the equimolar CrCoNi medium-entropy alloy and CrMnFeCoNi high-entropy alloy were studied in a gas atmosphere consisting of a volumetric mixture of 10% H2O, 2% O2, 0.5% SO2, and 87.5% Ar at 800 °C for up to 96 h. Both alloys were initially single-phase fcc with a mean grain size of ~ 50 μm and a homogeneous chemical composition. The oxide layer thickness of CrMnFeCoNi increased linearly with exposure time while it remained constant at ~ 1 μm for CrCoNi. A Cr2O3 layer and minor amounts of (Co,Ni)Cr2O4 developed on the latter while three oxide layers were detected on the former, i.e., a thin and continuous chromium rich oxide layer at the oxide/alloy interface, a dense (Mn,Cr)3O4 layer in the center and a thick and porous layer of Mn3O4 and MnSO4 at the gas/oxide interface. Additionally, a few metal sulfides were observed in the CrMnFeCoNi matrix. These results were found to be in reasonable agreement with thermodynamic calculations.
KW - high entropy alloys
KW - corrosion
KW - oxidation
KW - scanning electron microscopy
KW - sulfidation
KW - CrMnFeCoNi
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594189
DO - https://doi.org/10.1007/s44210-023-00026-8
SP - 1
EP - 17
PB - Springer Science and Business Media LLC
AN - OPUS4-59418
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sun, Yijuan
A1 - Gawlitza, Kornelia
A1 - Valderrey, Virginia
A1 - Bhattacharya, Biswajit
A1 - Rurack, Knut
T1 - Ratiometric Molecularly Imprinted Particle Probes for Reliable Fluorescence Signaling of Carboxylate-Containing Molecules
N2 - In addition to sensitivity, selectivity, and portability, chemical sensing systems must generate reliable signals and offer modular configurability to address various small molecule targets, particularly in environmental applications. We present a versatile, modular strategy utilizing ratiometric molecularly imprinted particle probes based on BODIPY indicators and dyes for recognition and internal referencing. Our approach employs polystyrene core particles doped with a red fluorescent BODIPY as an internal standard, providing built-in reference for environmental influences. A molecularly imprinted polymer (MIP) recognition shell, incorporating a green-fluorescent BODIPY indicator monomer with a thiourea binding site for carboxylate containing analytes, is grafted from the core particles in the presence of the analyte as the template. The dual-fluorescent MIP probe detects fexofenadine as the model analyte with a change in green emission signal referenced against a stable red signal, achieving a detection limit of 0.13 μM and a broad dynamic range from 0.16 μM to 1.2 mM, with good discrimination against other antibiotics in acetonitrile. By selecting a versatile dye scaffold and recognition element, this approach can be extended to other carboxylate-containing analytes and/or wavelength combinations, potentially serving as a robust multiplexing platform.
KW - Core-shell particles
KW - Molecular imprinting
KW - Pharmaceutical contaminants
KW - Self-referenced measurements
KW - Fluorescence
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609385
DO - https://doi.org/10.1021/acsami.4c09990
SP - 1
EP - 13
PB - American Chemical Society (ACS)
AN - OPUS4-60938
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - da Silva, D.A.
A1 - Greiser, Sebastian
A1 - Contro, J.
A1 - Medeiros, V.L.
A1 - Nery, J.G.
A1 - Jäger, Christian
T1 - 1H, 29Si and 119Sn double and triple resonance NMR spectroscopy of the
small-pore framework sodium stannosilicate Na2SnSi3O9⋅2H2O
N2 - The small-pore framework sodium stannosilicate AV-10, chemical composition Na2SnSi3O9⋅2H2O and known crystallographic structure, was synthesized by hydrothermal crystallization. This stannosilicate is built up of a three-dimensional network of corner-shared SiO4 tetrahedra and SnO6 octahedra. The SnO6 sites are linked to six SiO4 tetrahedra (Sn(6Si)) while each of the two crystallographically different SiO4 units are connected to two SnO6 and SiO4 units (Si(2Si,2Sn)). This material was used as model compound for developing a solid-state MAS NMR strategy aimed on the challenges and possibilities for structural studies, particularly considering the short and medium range order to verify the connectivity of SiO4 and SnO6 of such compounds despite the low natural abundances of 4.68% for 29Si and 8.59% for 119Sn nuclei as a real challenge. 29Si{119Sn} and 119Sn{29Si} REDOR (Rotational-Echo Double-Resonance) NMR measurements after 1H cross-polarization (CP) were carried out. The REDOR curves show a significant change after the “normal” quadratic short time evolution from which both (i) the shortest internuclear 29Si – 119Sn distances (and vice versa) and (ii) the number of corner-sharing SiO4 tetrahedra around the SnO6 octahedra (and vice versa) can be obtained. Based on these data, optimized 29Si {119Sn} and 119Sn{29Si} REPT-HMQC (Recoupled Polarization Transfer-Heteronuclear Multiple-Quantum Correlation, again after 1H CP) experiments were implemented, which directly show those heterogroup connectivity as correlation peaks in a 2D spectrum. This information was also obtained using 2D29Si{119Sn}-J-Coupling NMR experiments. Furthermore, 2D29Si INADEQUATE NMR experiments are also feasible, showing the connectivity of SiO4 tetrahedra. The combination of REDOR, REPT-HMQC, J-Coupling and INADEQUATE experiments yielded a complete analysis of the short and medium range structure of this microporous stannosilicate, in agreement with the previously published structure obtained Ab Initio from powder X-Ray diffraction data (XRD).
KW - Stannosilicates
KW - REDOR
KW - REPT-HMQC
KW - INADEQUATE
PY - 2020
DO - https://doi.org/10.1016/j.ssnmr.2020.101661
SN - 0926-2040
VL - 107
SP - 101661
PB - Elsevier Inc.
AN - OPUS4-50710
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Pauw, Brian Richard
A1 - Röder, Bettina
A1 - Smales, Glen Jacob
T1 - High temperature in-vacuum flow-through sample holder (sandwich design version 1.1)
N2 - Technical drawings and documents for building a compact, heated, vacuum compatible flow-through sample holder. This holder is in use at the BAM MOUSE instrument as well as at the I22 beamline at the Diamond Light Source (see references for instrument details).
This holder has several features:
- The holder can be used in vacuum environments as well as in atmosphere
- It has two G 1/4" UNF fittings to attach HPLC tubing for (optionally) flowing a medium through the sample cell
- There are two additional (unflowed) sample positions for backgrounds and calibrants, held at the same temperature
- The low-mass design coupled with a 250W heating element can achieve heating rates of 1 degree C per second, when coupled (for example) with an Omron E5CC PID controller.
- The sample holder insert can be made from various materials depending on the application. Sealing the sample from the vacuum can be achieved using kapton, teflon or Magic tape, depending on the temperature requirements. The inlet and outlet holes will need to be punctured with a needle to enable flow.
- Large exit cones ensure a clear exit angle of at least 45 degrees two theta.
- It has been tested with temperatures up to 400 degrees C.
- Compression area has been raised and polished to ensure a good vacuum seal.
KW - SAXS
KW - X-ray scattering
KW - Sample cell
KW - Sample holder
KW - Heated
KW - Flow-through
KW - Vacuum compatible
KW - XRD
KW - WAXS
PY - 2023
DO - https://doi.org/10.5281/zenodo.7501030
PB - Zenodo
CY - Geneva
AN - OPUS4-56777
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
ED - Hahn, Oliver
ED - Doil, Thorsten
T1 - Workshop Kulturguterhaltung - Vom Dampfkessel zu Nanomaterialien
N2 - Sehr geehrte Damen und Herren,
liebe Leserinnen und Leser,
bereits im ersten Band der N.i.Ke. Schriftenreihe des Netzwerks zur interdisziplinären Kulturerhaltung hatte ich angeführt, dass bei der Untersuchung von kulturellen Artefakten naturwissenschaftliche Untersuchungsmethoden zunehmend an Bedeutung gewinnen, sie eigentlich unverzichtbar geworden sind.
Ein besonders einprägsames Beispiel dieser fächerübergreifenden Zusammenarbeit zwischen Geisteswissenschaften, Naturwissenschaften und Restaurierungswissenschaften war die Ausstellung Johannes Vermeer. Vom Innehalten, die in diesem Jahr in der Gemäldegalerie Alter Meister in den staatlichen Kunstsammlungen Dresden gezeigt wurde. Eigens für diese Ausstellung wurde das Gemälde Brieflesendes Mädchen am offenen Fenster einer grundlegenden Restaurierung unterzogen. Diese Restaurierung diente jedoch nicht nur der Reparatur des Bildes. Um sich dem ursprünglichen Zustand des Gemäldes zwischen 1657 und 1659 anzunähern, wurden später hinzugefügte Malschichten großflächig abgenommen. Möglich wurde dies durch unterschiedliche, bildgebende materialwissenschaftliche Untersuchungen im Vorfeld, welche die wissenschaftlichen Grundlagen für die Diskussion über den weiteren Umgang mit der Lesenden schufen.
Materialanalytische Verfahren wurden und werden ständig weiterentwickelt und optimiert. Sei es, um aus einer Vielzahl von Einzelmessungen ein Gesamtbild zu erstellen, oder die Größe einer Probenentnahme so zu reduzieren, dass von einer „minimal-invasiven“ oder „quasi nicht-invasiven“ Untersuchung ausgegangen werden kann. Nun feiert die Bundesanstalt für Materialforschung und -prüfung, zusammen mit ihren Vorgängerinstitutionen, den königlichen Versuchsanstalten, in diesem Jahr ihren einhundertfünfzigsten Geburtstag. Sie blickt damit auf eine lange Tradition materialwissenschaftlicher Analysen zurück, an deren Beginn beispielsweise die metallographischen Untersuchungen von Adolf Martens stehen. Derartige Untersuchungen bilden auch heute noch einen wesentlichen Bestandteil archäometallurgischer Forschung. Die Historie bzw. die Weiterentwicklung der Methodik lässt sich hier besonders gut nachzeichnen. Jedoch blicken auch Verfahren zur Charakterisierung weiterer Werkstoffe, wie Glas, Keramik, oder organischer Materialien auf eine lange Geschichte zurück.
Die in diesem Band der N.i.Ke.-Schriftenreihe präsentierten Beiträge dokumentieren einerseits aktuelle Forschungsarbeiten, die erst in diesem Jahr in entsprechenden Fachjournalen publiziert wurden, andererseits liegen einige der Arbeiten bereits 50 Jahre zurück. Sie bekunden damit nicht nur die materialtechnologische und historische Bandbreite der Projekte, sondern offenbaren die Vielfältigkeit kulturhistorischer oder restauratorischer Fragestellungen, zu deren Beantwortung natur- und materialwissenschaftliche Forschung wesentliche Beiträge liefern können.
Ich bedanke mich bei allen Kolleginnen und Kollegen, die zur Erstellung dieser dritten Ausgabe der N.i.Ke. Schriftenreihe des Netzwerks zur interdisziplinären Kulturerhaltung beigetragen haben. Ihre Aufsätze ermöglichen den Blick in die Vielfältigkeit materialwissenschaftlicher Untersuchungen im Bereich Kunst- und Kulturgut. Ich wünsche Ihnen viel Spaß auf dieser kleinen Zeitreise.
T2 - Workshop Kulturguterhaltung - Vom Dampfkessel zu Nanomaterialien
CY - Berlin, Germany
DA - 17.11.2021
KW - Pergamonmuseums
KW - Schriftrollen vom Toten Meer
KW - Gold mit Synchrotronstrahlung
KW - Kandelaber des Ensembles am Charlottenburger Tor
KW - Berliner Tuffsteinfassaden
KW - Betondickglasfenster des Glockenturms am Eiermannbau
KW - Kaiser-Wilhelm-Gedächtniskirche
KW - Radiografische Untersuchung
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543239
UR - https://netzwerke.bam.de/Netzwerke/Navigation/DE/Netzwerke/NIKE/nike.html
VL - 3
SP - 1
EP - 155
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-54323
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Manzoni, Anna Maria
T1 - Effect of a mixed atmosphere H2O-O2-SO2 on the oxidation kinetics and phase formation on CrMnFeCoNi and CrCoNi
N2 - The high-temperature corrosion behaviors of the equimolar CrCoNi medium- and CrMnFeCoNi high-entropy alloy were studied in a gas atmosphere consisting of a volumetric mixture of 10% H2O, 2% O2, 0.5% SO2, and 87.5% Ar at 800 °C for up to 96 h. Both alloys were initially single-phase fcc structured and showed a mean grain size of ~50 µm and a homogeneous chemical composition. The oxide layer thickness of the Cantor alloy CrMnFeCoNi increased linearly with exposure time while it remained constant at ~1 µm for CrCoNi. A Cr2O3 layer and minor amounts of (Co,Ni)Cr2O4 developed on CrCoNi while three layers were detected on the Cantor alloy. These layers were a thin and continuous chromium rich oxide layer at the oxide/alloy interface, a dense (Mn,Cr)3O4 layer in the center and a thick and porous layer of Mn3O4 and MnSO4 at the gas/oxide interface. Additionally, a few metal sulfides were observed in the CrMnFeCoNi matrix. These results were found to be in reasonable agreement with thermodynamic calculations.
T2 - ICHEM 2023
CY - Knoxville, TN, USA
DA - 18.06.2023
KW - High entropy alloys
KW - Chemically complex alloys
KW - Corrosion
KW - Mixed gas atmosphere
PY - 2023
AN - OPUS4-57776
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Manzoni, Anna Maria
A1 - Haas, S.
A1 - Kropf, H.
A1 - Duarte, J.
A1 - Cakir, Cafer Tufan
A1 - Dubois, F.
A1 - Többens, D.
A1 - Glatzel, U.
T1 - Temperature evolution of lattice misfit in Hf and Mo variations of the Al 10 Co 25 Cr 8 Fe 15 Ni 36 Ti 6 compositionally complex alloy
N2 - Misfits of γ- γ’ based Al10Co25Cr8Fe15Ni36Ti6 and its Mo- and Hf-variations are studied up to a temperature of 980 °C and compared with Ni- and Co-based superalloys. The trace elements decrease (Hf) or increase (Mo) the edge radii of the γ’ cuboids without changing their sizes. Atom probe measurements revealed that the Hf alloy prefers the γ’ phase while Mo prefers the γ matrix, leading to a lattice parameters enhancement of both phases, as could be revealed by synchrotron X-ray diffraction. The misfit is influenced in opposite ways: Hf increases the positive misfit, while Mo reduces it at all investigated temperatures.
KW - Metal and alloys
KW - Transmission electron microscopy
KW - X-ray diffraction
KW - Atom probe tomography
KW - High entropy alloy
PY - 2020
DO - https://doi.org/10.1016/j.scriptamat.2020.07.013
VL - 188
SP - 74
EP - 79
PB - Elsevier Ltd.
AN - OPUS4-51025
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stawski, Tomasz
T1 - Towards sustainable solution-driven recycling of gypsum
N2 - Calcium sulfate hemihydrate (CaSO4ᐧ0.5H2O), also known as bassanite, has been used as a precursor to produce gypsum (dihydrate, CaSO4ᐧ2H2O) for various construction and decorative purposes since prehistoric times. The main route to obtain hemihydrate is a thermal treatment of gypsum at temperatures typically between 150 °C and 200 °C to remove some of the structural water. In this contribution, we introduce (Fig. 1) a more efficient and sustainable method (T < 100 °C) that enables the direct, rapid, and reversibly conversion of gypsum to bassanite using reusable high salinity aqueous solutions (brineswith c[NaCl] > 4 M). The optimum conditions for the efficient production of bassanite in a short time (< 5 min) involve the use of brines with c(NaCl) > 4 M and maintaining a temperature, T > 80 °C. When the solution containing bassanite crystals is cooled down to around room temperature, eventually gypsum is formed. When the temperature is raised again to T > 80 °C, bassanite is rapidly re-precipitated. This contrasts with the typical behaviour of the bassanite phase in low salt environments. Traditionally, hemihydrate is obtained through a solid state thermal treatment because bassanite is considered to be metastable with respect to gypsum and anhydrite in aqueous solutions, and therefore gypsum-to-bassanite conversion should not occur in water. Its very occurrence actually contradicts numerical thermodynamic predictions regarding solubility of calcium sulfate phases. By following the evolution of crystalline phases with in situ and time-resolved X-ray diffraction/scattering and Raman spectroscopy, we demonstrated that the phase stability in brines at elevated temperatures is inaccurately represented in the thermodynamic databases. Most notably for c(NaCl) > 4 M, and T > 80 °C gypsum becomes readily more soluble than bassanite, which induces the direct precipitation of the latter from gypsum. The fact that these transformations are controlled by the solution provides extensive opportunities for precise manipulation of crystal formation. Our experiments confirmed that bassanite remained the sole crystalline structure for many hours before reverting into gypsum. This property is extremely advantageous for practical processing and efficient crystal extraction in industrial scenarios.
T2 - RAL-SAS - UK Small angle scattering meeting 2025
CY - Oxford, United Kongdom
DA - 16.06.2025
KW - Scattering
KW - SAXS
KW - Calcium sulfate
KW - Gypsum
PY - 2025
AN - OPUS4-64682
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Stawski, Tomasz
A1 - Miliute, Aiste
T1 - Structural Refinement of ZrV₂O₇ with Negative Thermal Expansion Using Pair Distribution Function Analysis
N2 - This repository contains Python scripts specifically developed for structural refinement of Zirconium Vanadate (ZrV₂O₇), a material known for its negative thermal expansion (NTE). The scripts implement Pair Distribution Function (PDF) analysis to refine crystal structures directly from experimental X-ray diffraction (XRD) data. The refinement workflow is built around the DiffPy-CMI library, enhanced with custom functionalities tailored for ZrV₂O₇ and similar oxide materials.
KW - Zirconium vandate
KW - Total scattering
KW - Pair distribution function
KW - Structure refinement
PY - 2025
DO - https://doi.org/10.5281/zenodo.15395752
PB - Zenodo
CY - Geneva
AN - OPUS4-64750
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Manzoni, Anna Maria
T1 - Corrosion in the Co-Cr-Fe-Ni high entropy alloy family
N2 - While a lage amount of research on high entropy alloys is oriented towards mechanical properties and the microstructural improvement it is also necessary to keep an eye on the environment that potential application materials will be submitted to. The Co-Cr-Fe-Ni based high entropy family has shown great potential over the years of high entropy research and some candidate alloys are chosen for an insight into their corrosion behaviour. Several atmospheres are studied, i.e. O2, H2O, SO2 and a mix thereof in argon as well as synthetic air. Just as for classic alloys, the chromium is the most important element in terms of protection agains further corrosion. The addition of manganese, as in case of the “Cantor alloy” CrMnFeCoNi, overpasses Cr when it comes to oxygen affinity and thus counteracts the layer formation of Cr2O3. Even without Mn, a temperature chosen too high will also affect the formation of the chromium oxide layer and spall it off, annulling its protective potential. We can also observe how trace elements influence the layer formation. These effects and their mechanisms will be discussed for the alloys CrFeNi, CoCrNi, CrMnFeCoNi and variations of Al10Co25Cr8Fe15Ni36Ti6 using a combination of electron microscopy, thermodynamic calculations and x-ray diffraction.
T2 - MRS-T International Conference
CY - Hsinchu, Taiwan
DA - 17.11.2023
KW - Corrosion
KW - Scanning electron microscopy
KW - Mixed gas atmosphere
PY - 2023
AN - OPUS4-58980
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -