TY - CONF
A1 - Hertwig, Andreas
A1 - Ermilova, Elena
T1 - Ellipsometry as a production measurement tool
N2 - Spectroscopic Ellipsometry is an enormously versatile measurement tool for surfaces and thin layers. We discuss the use of ellipsometry in the context of quality control in production processes of eletrconic devices.
T2 - Photonics Days Berlin Brandenburg
CY - Berlin, Germany
DA - 09.10.2023
KW - Ellipsometry
KW - Quality control
KW - Metrology
PY - 2023
AN - OPUS4-59837
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Omar, Hassan
A1 - Szymoniak, Paulina
A1 - Hertwig, Andreas
A1 - Schönhals, Andreas
T1 - Growth Kinetics and Molecular Mobility of the Adsorbed Layer of Poly(bisphenol-A Carbonate) (PBAC), Polysulfone (PSU), and Poly (2-Vinyl Pyridine) (P2VP)
N2 - Interactions between a polymer and a substrate interface play a vital role in understanding the improvement in thin film material properties as well as serving as a model for nanocomposites. For any non-repulsive polymer-substrate interactions, polymer segments form an irreversibly adsorbed layer and show a slowdown in the glassy dynamics and thus an increase in the thermal glass transition temperature compared to the bulk-like values. The growth kinetics of the adsorbed layer showed a deviation for both poly (bisphenol-A carbonate) (PBAC) and polysulfone (PSU), two bulky polymers containing a functional group (phenyl ring) in the backbone, compared to conventional polymers previously studied like poly-2-vinyl pyridine (P2VP). This deviation was attributed to the bulkiness of the phenyl rings. . Further investigations into the influence of the adsorbed layer on glassy dynamics were conducted. The molecular mobility and glass transition for thin films of PBAC and PSU were compared to bulk samples of each polymer. Broadband dielectric spectroscopy, atomic force microscopy, and ellipsometry were primarily used and additionally supported by sum frequency generation spectroscopy.
T2 - Deutsche Physikalische Gesellschaft (DPG) Tagung
CY - Berlin, Germany
DA - 17.03.2024
KW - Thin films
KW - Adsorbed Layer
KW - Atomic Force Microscopy
KW - Ellipsometry
KW - Dielectric Spectroscopy
PY - 2024
AN - OPUS4-59821
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Pauw, Brian Richard
A1 - Smales, Glen Jacob
A1 - Hörmann, Anja
A1 - Moeez, Abdul
A1 - Breßler, Ingo
T1 - BAMresearch/HDF5Translator: A Framework for translating and transforming data between HDF5 files
N2 - HDF5Translator is a Python framework for translating and transforming data between HDF5 files. It supports operations like unit conversion, dimensionality adjustments, and subtree copying, making it suitable for managing and manipulating a wide range of scientific datasets.
KW - Measurement data conversion
KW - Data conversion
KW - HDF5
KW - NeXus
KW - NXsas
KW - Framework
KW - Python
KW - Methodology
PY - 2024
DO - https://doi.org/10.5281/zenodo.10927639
PB - Zenodo
CY - Geneva
AN - OPUS4-59797
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Pauw, Brian Richard
A1 - Smales, Glen Jacob
A1 - Moeez, A.
A1 - Hörmann, Anja
A1 - Breßler, Ingo
T1 - Example configurations and test cases for the Python HDF5Translator framework.
N2 - This is a set of use examples for the HDF5Translator framework. This framework lets you translate measurement files into a different (e.g. NeXus-compatible) structure, with some optional checks and conversions on the way. For an in-depth look at what it does, there is a blog post here.
The use examples provided herein are each accompanied by the measurement data necessary to test and replicate the conversion. The README.md files in each example show the steps necessary to do the conversion for each.
We encourage those who have used or adapted one or more of these exampes to create their own conversion, to get in touch with us so we may add your example to the set.
KW - Measurement data conversion
KW - Data conversion
KW - HDF5
KW - NeXus
KW - NXsas
KW - Framework
KW - Python
PY - 2024
DO - https://doi.org/10.5281/zenodo.10925971
PB - Zenodo
CY - Geneva
AN - OPUS4-59796
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hoogendoorn, Levi
A1 - Huertas, Mauricio
A1 - Nitz, Phillip
A1 - Qi, Naiyu
A1 - Baller, Johannes
A1 - Prinz, Carsten
A1 - Graeber, Gustav
T1 - Sustainable, Low‐Cost Sorbents Based on Calcium Chloride‐Loaded Polyacrylamide Hydrogels
N2 - AbstractSorbents are promising materials for applications in atmospheric water harvesting, thermal energy storage, and passive cooling, thereby addressing central challenges related to water scarcity and the global energy transition. Recently, hygroscopic hydrogel composites have emerged as high‐performance sorbents. However, many of these systems are fabricated with unsustainable and costly sorbent materials, which hinders their wide deployment. Here, the synthesis of high‐performance, cost‐efficient polyacrylamide hydrogels loaded with unprecedented amounts of calcium chloride is demonstrated. To this end, the swelling procedure of polyacrylamide hydrogels in aqueous calcium chloride solutions is optimized. The achievable salt loading in the hydrogel is characterized as a function of temperature, calcium chloride concentration in the swelling solution, and the hydrogel preparation conditions. The obtained hydrogel‐salt composites are shown to be stable under repeated sorption‐desorption cycling and enable water uptakes of 0.92 and 2.38 grams of water per gram of dry materials at 30% and 70% relative humidity, respectively. The resulting cost‐performance ratio substantially exceeds lithium chloride‐based systems. Further, the mechanistic insights on hydrogel salt interactions can guide the design of sustainable and low‐cost sorbent materials for future applications in water and energy.
KW - Electrochemistry
KW - Condensed Matter Physics
KW - Biomaterials
KW - Electronic, Optical and Magnetic Materials
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598366
DO - https://doi.org/10.1002/adfm.202314680
SN - 1616-301X
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-59836
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, H.
A1 - Weidner, Steffen
A1 - Meyer, A.
T1 - Syntheses of high molecular mass polyglycolides via ring-opening polymerization with simultaneous polycondensation(ROPPOC) by means of tin and zinc catalysts
N2 - Glycolide was polymerized in bulk by means of four different ROPPOC catalysts: tin(II) 2-ethylhexanoate (SnOct2), dibutyltin bis(pentafluoro-phenoxide) (BuSnOPF),zinc biscaproate (ZnCap), and zinc bis(pentafluoro-phenyl sulfide) (ZnSPF). The temperature was varied between 110 and 180°C and the time between 3 h and 7 days. For the few polyglycolides (PGAs) that were soluble extremely high molecular masses were obtained. The MALDI TOF mass spectra had all a low signal-to-noise ration and displayed the peaks of cyclic PGAs with a“saw-tooth pattern ”indicating formation of extended-ring crystallites in the mass range below m/z 2500. The shape of DSC curves varied considerably with catalyst and reaction conditions, whereas the long-distance values measured by SAXS were small and varied little with the polymeriza-tion conditions.
KW - MALDI TOF MS
KW - Polyglycolide
KW - Crystalinity
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598221
DO - https://doi.org/10.1002/pat.6365
VL - 35
IS - 4
SP - 1
EP - 10
PB - John Wiley & Sons Ltd.
AN - OPUS4-59822
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Knapic, D.
A1 - Mardare, A. I.
A1 - Voss, Heike
A1 - Bonse, Jörn
A1 - Hassel, A. W.
T1 - Corrosion study of picosecond-laser structured and anodized Ti6Al4V for bone screws
N2 - A corrosion study is performed on six variations of titanium grade 5 (Ti6Al4V) samples. Samples are prepared in different conditions by variation of preanodization, postanodization, and picosecond-laser (ps-laser) surface treatment, while polished and anodized samples serve as reference. Microcones and nanosized periodic surface features are successfully produced on Ti6Al4V samples. The morphology and topography of the structures are visualized by scanning electron microscopy and white light interference microscopy. Furthermore, the relative electrochemically active surface area (ECSA) is determined for the ps-laser-treated samples. It is determined that the preanodized and laser-treated sample has 3.5 times larger ECSA than a polished sample, and that the laser-treated sample has 4.1 times larger area. Moreover, Tafel analysis is performed to determine the corrosion properties of the samples. It is shown that the corrosion resistance improves for both laser-structured samples after the anodization. To further study the surface of the samples, electrochemical impedance spectroscopy measurements are conducted. The study indicates that the ps-laser-treated and anodized Ti6Al4V is suitable to be used for the fabrication of bone screws and plates due to its improved corrosion resistance as compared to nonanodized samples.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Anodization
KW - Bone screws
KW - Implant material
KW - Titanium alloys
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597890
DO - https://doi.org/10.1002/pssa.202300609
SN - 1862-6319
VL - 221
SP - 1
EP - 8
PB - Wiley-VCH GmbH
CY - Weinheim
AN - OPUS4-59789
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pellegrino, F.
A1 - Rossi, A.
A1 - Sordello, A.
A1 - Sordello, F.
A1 - Alladio, E.
A1 - Santalucia, R.
A1 - Primieri, A.
A1 - Hodoroaba, Vasile-Dan
A1 - Radnik, Jörg
A1 - Maurino, V.
T1 - Safe-by-Design Synthesis of 2D Materials
N2 - The use of a dedicated approach: DoE for synthesis + characterization + Chemometric Analysis, is a valuable method for the safe-by-design synthesis of several types of materials for large-scale application in catalysis, energy harvesting, biomedical and environmental applications, etc. This approach is not only related to the material synthesis, but can be expanded to any type of molecules/material, with relevant saving of solvents, energy and times.
T2 - Congress of the Environment and Cultural Heritage - Section of Italian Chemistry Society
CY - Ischia, Italy
DA - 28.09.2023
KW - Safe-by-design
KW - 2D materials
KW - Synthesis
KW - Chemometric analysis
PY - 2023
UR - https://www.congressodabc.it/
AN - OPUS4-59780
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Schiek, Manuela
A1 - Minenkov, Alexey
A1 - Hollweger, Sophia
A1 - Duchoslav, Jiri
A1 - Erdene-Ochir, Otgonbayar
A1 - Weise, Matthias
A1 - Ermilova, Elena
A1 - Hertwig, Andreas
T1 - Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
N2 - Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
Minenkov et al. 2024: on glass; n,k 0.191–1.69 µm
Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
Minenkov et al. 2024: on Si wafer, top; n,k 0.191–1.69 µm
Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
Minenkov et al. 2024: on Si wafer, bottom; n,k 0.191–1.69 µm
KW - Indium Tin Oxide
KW - Optical constants
KW - Magnetron Sputtering
KW - Electrochemical Degradation
KW - Spectroscopic Ellipsometry
PY - 2024
UR - https://refractiveindex.info/?shelf=other&book=In2O3-SnO2&page=Minenkov-glass
UR - https://refractiveindex.info/?shelf=other&book=In2O3-SnO2&page=Minenkov-wafer-top
UR - https://refractiveindex.info/?shelf=other&book=In2O3-SnO2&page=Minenkov-wafer-bottom
PB - Refractiveindex.info
AN - OPUS4-59766
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hertwig, Andreas
T1 - New analytic ways to characterise mesoporous thin layers used in electrocatalytic water splitting
N2 - Mesoporous materials are needed in many applications where a high specific surface area and adsorptive behaviour is needed. Important examples are separation techniques and barrier layers and catalysts. Electrochemical water splitting is the key technology for producing green hydrogen and there is no foreseeable alternative to this process for producing elementary hydrogen from green electrical power. Water electrolysis can be divided into the anodic Oxygen Evolution Reaction (OER) and the cathodic Hydrogen Evolution Reaction (HER). Both processes have to be heavily optimised to a large extent to avoid energy losses caused by overvoltage. The development of electrodes for these processes is especially difficult due to the many boundary conditions. Water splitting is a catalytic as well as electrochemical process. The contact area between the electrolyte and the electrode must be maximised maintaining the stability of the surface. Side reactions must be suppressed, and effective gas transport must be ensured. The whole process has to be tolerant with respect to temperature, harsh chemical conditions from the electrolyte as well as high current densities.
We present a hybrid analytical method combining several analytical techniques for determining the properties of thin layers of mixed oxides of the general composition Ir:TiOx. These materials are promising candidates for electrocatalytical top coatings of OER electrodes. To lower the costs of the electrolysers, the main goal is to lower the Ir content retaining the system efficiency. The main properties which are hard to determine are the porous volume fraction and the Ir:Ti element ratio. By a combination of electron microscopy, spectroscopic operando ellipsometry, ellipsometric porosimetry, and other techniques, we can determine key features of mesoporous thin layer materials. We aim to develop operando capable techniques used in process monitoring as well as measurement techniques optimised for accuracy. By developing reference materials, we support long term uptake of our methodology. This work can directly be used for optimising electrocatalytic layers and is a good example for the power of hybrid metrology for improving materials design.
T2 - International Conference on Resource Chemistry
CY - Alzenau, Germany
DA - 11.03.2024
KW - Ellipsometry
KW - Electrocatalytic Water Splitting
KW - Mesoporous Materials
KW - Electron Probe Microanalysis
KW - Hydrogen Generation
PY - 2024
AN - OPUS4-59764
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hertwig, Andreas
A1 - Ermilova, Elena
A1 - Cotroneo, Vincenzo
A1 - Gibertini, Eugenio
A1 - Stanik, Eva
A1 - Döhring, Thorsten
T1 - Characterisation of thin layers of Polydopamine used as functional coatings in X-Ray optics
N2 - Polydopamine (PDA) is a biological / biomimetic polymer which has spiked considerable interest in recent years. Its monomer is an important neurotransmitter and it is one of the strongest glues produced by biological organisms. Polydopamine is a candidate for several applications, mainly in the field of biology and medicine, but also - recently - for layer coatings with optical, electrical, and mechanical function.
In this work, we investigate PDA layers intended as reflectivity enhancers for mirror surfaces in X-ray astronomical observatories. It has previously been shown, that such X-ray telescopes can be improved by a coating of PDA in the thickness range of several nm. Accurate thickness determination is required to monitor and optimise the coating process. We use spectroscopic ellipsometry to determine first the dielectric function of the polydopamine layers using model coatings of sufficient thickness. This data is then used to accurately determine the layer thickness of much thinner PDA layers. This study resulted in data on the thickness and dielectric function of PDA layers that could lead to a better understanding of the correlation of layer thickness and layer properties depending on the process parameters.
T2 - Deutsche Physikalische Gesellschaft - Frühjahrstagung
CY - Berlin, Germany
DA - 17.03.2024
KW - Ellipsometry
KW - Polydopamine
KW - Thin Polymer Layers
KW - X-Ray Reflectometry
KW - Biopolymers
PY - 2024
AN - OPUS4-59760
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Peters, Stefan
A1 - Bartling, Stephan
A1 - Parlinska-Wojtan, Magdalena
A1 - Wotzka, Alexander
A1 - Guilherme Buzanich, Ana
A1 - Wohlrab, Sebastian
A1 - Abdel-Mageed, Ali M.
T1 - Stabilization of intermediate Mo oxidation states by Nb doping enhancing methane aromatization on Mo/HZSM-5 catalysts
N2 - The dehydroaromatization of methane is a promising process to produce aromatics and ultra-pure hydrogen. Increased yields and stability of Mo/HZSM-5 against irreversible deactivation were achieved via a redox interaction by doping with otherwise inert Nb.
KW - General Materials Science
KW - Sustainability and the Environment
KW - General Chemistry
KW - Renewable Energy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597670
DO - https://doi.org/10.1039/D3TA07532J
SN - 2050-7488
SP - 1
EP - 16
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59767
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Minenkov, Alexey
A1 - Hollweger, Sophia
A1 - Duchoslav, Jiri
A1 - Erdene-Ochir, Otgonbayar
A1 - Weise, Matthias
A1 - Ermilova, Elena
A1 - Hertwig, Andreas
A1 - Schiek, Manuela
T1 - Monitoring the Electrochemical Failure of Indium Tin Oxide Electrodes via Operando Ellipsometry Complemented by Electron Microscopy and Spectroscopy
N2 - Transparent conductive oxides such as indium tin oxide (ITO) are standards for thin film electrodes, providing a synergy of high optical transparency and electrical conductivity. In an electrolytic environment, the determination of an inert electrochemical potential window is crucial to maintain a stable material performance during device operation. We introduce operando ellipsometry, combining cyclic voltammetry (CV) with spectroscopic ellipsometry, as a versatile tool to monitor the evolution of both complete optical (i.e., complex refractive index) and electrical properties under wet electrochemical operational conditions. In particular, we trace the degradation of ITO electrodes caused by electrochemical reduction in a pH-neutral, water-based electrolyte environment during electrochemical cycling. With the onset of hydrogen evolution at negative bias voltages, indium and tin are irreversibly reduced to the metallic state, causing an advancing darkening, i.e., a gradual loss of transparency, with every CV cycle, while the conductivity is mostly conserved over multiple CV cycles. Post-operando analysis reveals the reductive (loss of oxygen) formation of metallic nanodroplets on the surface. The reductive disruption of the ITO electrode happens at the solid–liquid interface and proceeds gradually from the surface to the bottom of the layer, which is evidenced by cross-sectional transmission electron microscopy imaging and complemented by energy-dispersive X-ray spectroscopy mapping. As long as a continuous part of the ITO layer remains at the bottom, the conductivity is largely retained, allowing repeated CV cycling. We consider operando ellipsometry a sensitive and nondestructive tool to monitor early stage material and property changes, either by tracing failure points, controlling intentional processes, or for sensing purposes, making it suitable for various research fields involving solid–liquid interfaces and electrochemical activity.
KW - General Materials Science
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597625
DO - https://doi.org/10.1021/acsami.3c17923
SN - 1944-8252
VL - 16
IS - 7
SP - 9517
EP - 9531
PB - American Chemical Society (ACS)
AN - OPUS4-59762
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dittmar, Stefan
A1 - Ruhl, Aki S.
A1 - Altmann, Korinna
A1 - Jekel, Martin
T1 - Settling Velocities of Small Microplastic Fragments and Fibers
N2 - There is only sparse empirical data on the settling velocity of small, non-buoyant microplastics thus far, although it is an important parameter governing their vertical transport within aquatic environments. This study reports the settling velocities of 4031 exemplary microplastic particles. Focusing on the environmentally most prevalent particle shapes, irregular microplastic fragments of four different polymer types (9–289 µm) as well as five discrete length fractions (50–600 µm) of common nylon and polyester fibers were investigated, respectively. All settling experiments were carried out in quiescent water using a specialized optical imaging setup. The method has been previously validated in order to minimize disruptive factors, e.g. thermal convection or particle interactions, and thus enable the precise measurements of the velocities of individual microplastic particles (0.003–9.094 mm/s). Based on the obtained data, ten existing models for predicting a particle’s terminal settling velocity were assessed. It is concluded that models, which were specifically deduced from empirical data on larger microplastics, fail to provide accurate predictions for small microplastics. Instead, a different approach is highlighted as a viable option for computing settling velocities across the microplastics continuum in terms of size, density and shape.
KW - Microplastics
KW - Microplastic fibers
KW - Settling velocity
KW - Sinking velocity
KW - Sedimentation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597455
DO - https://doi.org/10.1021/acs.est.3c09602
SN - 0013-936X
VL - 58
IS - 14
SP - 6359
EP - 6369
PB - American Chemical Society (ACS)
AN - OPUS4-59745
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wiesner, Yosri
A1 - Hoffmann, Thomas
A1 - Range, David
A1 - Altmann, Korinna
T1 - Microplastics in sediments of the river Rhine—A workflow for preparation and analysis of sediment samples from aquatic river systems for monitoring purposes
N2 - AbstractMicroplastics (MP) can be detected in all environmental systems. Marine and terrestrial aquatic systems, especially the transported suspended solids, have often been the focus of scientific investigations in the past. Sediments of aquatic river systems, on the other hand, were often ignored due to the time‐consuming sample preparation and analysis procedures. Spectroscopic measurement methods counting particle numbers are hardly suitable as detection methods, because there are plenty of natural particles next to a small number of MP particles. Integral methods, such as thermoanalytical methods are determining the particle mass independently of the inorganic components.In this study, a workflow for sample preparation via density separation and subsequent analysis by thermal extraction desorption‐gas chromatography/mass spectrometry is presented, which leads to representative and homogeneous samples and allows fast and robust MP mass content measurements suitable for routine analysis. Polymers were identified and quantified in all samples. Polyethylene and styrene‐butadiene rubber are the dominant polymers, besides polypropylene and polystyrene. Overall, total polymer masses between 1.18 and 337.0 µg/g could be determined. Highest MP concentrations in riverbed sediment are found in sites characterized by low flow velocities in harbors and reservoirs, while MP concentrations in sandy/gravelly bed sediments with higher flow velocities are small.
KW - Microplastics
KW - Density separation
KW - TED-GC/MS
KW - NaI
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597335
DO - https://doi.org/10.1002/appl.202200125
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-59733
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weidner, Steffen
A1 - Meyer, A.
A1 - Kricheldorf, H.
T1 - Transformation of poly(L-lactide) crystals composed of linear chains into crystals composed of cycles
N2 - A poly(L-lactide) with a trifluoroethyl ester end group and an average degree of polymerization (DP) of 50 was synthesized by ROP of L-lactide initiated with trifluoroethanol. Small-angle X-ray scattering (SAXS) in combination with differential scanning calorimetry (DSC) measurements revealed an average crystal thickness of 13 nm, corresponding to 45 repeat units. This suggests that most crystallites were formed by extended PLA chains, and both flat surfaces were covered by CF3 groups. The crystalline PLAs were annealed at 140 or 160 °C in the presence of two catalysts: tin(II) 2-ethylhexanoate, (SnOct2) or dibutyltin bis(pentafluorophenoxide) (BuSnPhF). The chemical reactions, such as polycondensation and cyclization, proceeded in the solid state and were monitored by matrix-assisted laser desorption/ionization time-offlight (MALDI TOF) mass spectrometry and gel permeation chromatography (GPC) measurements. Under optimal conditions a large fraction of linear chains was transformed into crystallites composed of extended cycles. Additionally, MALDI TOF MS analysis of GPC fractions from samples annealed for 28 or 42 days detected chain elongation of the linear species up to a factor of 20.
KW - Polylactide
KW - MALDI-TOF MS
KW - Crystalinity
KW - Transesterification
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597250
DO - https://doi.org/10.1039/D3PY01370G
SN - 1759-9954
VL - 15
IS - 12
SP - 1173
EP - 1181
PB - Royal Society for Chemistry
AN - OPUS4-59725
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Božičević, Lucija
A1 - Altmann, Korinna
A1 - Hildebrandt, Jana
A1 - Knigge, Xenia
A1 - Vrček, Valerije
A1 - Peranić, Nikolina
A1 - Kalcec, Nikolina
A1 - Vinkovic Vrcek, Ivana
T1 - Estrogenic activity of plastic nanoparticles mixture under in vitro settings
N2 - The plastic value chain, central part of modern living, caused environmental pollution and bioaccumulation of plastic nanoparticles (PNPs). Their ubiquitous presence in different environmental and biological compartments has become a serious threat to human health and ecosystems. Frequently used plastic materials such as polypropylene (PP), polystyrene (PS) and polyethylene (PE) have been detected in the form of PNPs in the food chain, soil, water and air, as well as in human feces and blood. In this study, we aimed to provide novel insights in endocrine disrupting properties of PNPs using in vitro estrogen receptor (ER) transactivation assay. The effects of PP-NPs, PE-NPs and PS-NPs and their mixture on T47D-KBluc cell line stably transfected with luciferase as reporter enzyme was evaluated by means of cytotoxicity, cellular uptake and ER activation. Tested dose range for PNPs was 0.001 – 10 mg/L. Both cellular uptake and cytotoxicity for all PNPs was found to be dose-dependent. Only the highest dose of PP-NPs and PE-NPs induced apoptosis and cell death, while PS-NPs were not cytotoxic in tested dose range. For tested concentrations, PP-NPs and PE-NPs showed significant agonistic activity on ER, while PS-NPs cannot be considered ER active. When, applied as mixture, PNP demonstrated additive toxicity effects compared to the effect of each individual PNPs. Additivity was also observed for ER agonistic effect of PNPs mixture according to the benchmark dose-addition modelling approach. This study provides missing science-based evidence on endocrine disrupting effects of PE-NPs, PP-NPs, PS-NPs and their mixtures and highlights the importance of considering unintentional, aggregate and combined exposure to different PNPs in risk management.
KW - Risk assessment
KW - Nanoplastics
KW - Estrogenic activity of plastic nanoparticles
PY - 2024
DO - https://doi.org/10.1039/D3EN00883E
SN - 2051-8153
VL - 11
IS - 5
SP - 2112
EP - 2126
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59724
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - High-throughput and automated bonding Analysis
N2 - Talk as a part of the LOBSTER CECAM SCHOOL. This talk introduced all participants to automation tools around the software LOBSTER.
T2 - CECAM LOBSTER School
CY - Aalto, Finland
DA - 12.03.2024
KW - Automation
KW - Workflows
KW - Bonding Analysis
KW - Materials Design
KW - Chemically Complex Materials
PY - 2024
AN - OPUS4-59672
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Data-Driven Chemical Understanding with Bonding Analysis
N2 - Bonds and local atomic environments are crucial descriptors of material properties. They have been used to create design rules and heuristics and as features in machine learning of materials properties. Implementations and algorithms (e.g., ChemEnv and LobsterEnv) for identifying local atomic environments based on geometrical characteristics and quantum-chemical bonding analysis are nowadays available. Fully automatic workflows and analysis tools have been developed to use quantum-chemical bonding analysis on a large scale. The lecture will demonstrate how our tools, that assess local atomic environments and perform automatic bonding analysis, help to develop new machine learning models and a new intuitive understanding of materials. Furthermore, the general trend toward automation in density functional-based materials science and some of our recent contributions will be discussed.
T2 - Otaniemi Center for Atomic-scale Materials Modeling Seminar
CY - Aalto, Finland
DA - 11.03.2024
KW - Automation
KW - Materials Design
KW - Bonding Analysis
KW - Machine Learning
PY - 2024
AN - OPUS4-59671
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Krüger, Jörg
T1 - Gefährdung durch Röntgenemission bei der UKP-Laser-Materialbearbeitung
N2 - Der Vortrag gibt einen Überblick zu ultrakurzen Laserpulsen, der Ultrakurzpulslaser-Materialbearbeitung und der dabei ggf. auftretenden unerwünschten Röntgenstrahlung. Es wird die Laserbearbeitung von technischen und biologischen Materialien diskutiert. Schutzmöglichkeiten gegenüber der Röntgenstrahlung werden erörtert.
T2 - Sonthofer Strahlenschutztage 2024
CY - Sonthofen, Germany
DA - 11.03.2024
KW - Ultrakurzpulslaser
KW - Laser-induzierte Röntgenstrahlung
KW - Materialbearbeitung
KW - Technische Materialien
KW - Biologische Anwendungen
PY - 2024
AN - OPUS4-59667
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wetzel, Annica
A1 - Morell, Daniel
A1 - von der Au, Marcus
A1 - Wittstock, Gunther
A1 - Ozcan, Ozlem
A1 - Witt, Julia
T1 - Transpassive Metal Dissolution vs. Oxygen Evolution Reaction: Implication for Alloy Stability and Electrocatalysis
T1 - Transpassive Metallauflösung vs. Sauerstoffentwicklung:
Auswirkungen auf Legierungsstabilität und Elektrokatalyse
N2 - Multi-principal element alloys (MPEAs) are gaining interest in corrosion and electrocatalysis research due to their electrochemical stability across a broad pH range and the design flexibility they offer. Using the equimolar CrCoNi alloy, we observe significant metal dissolution in a corrosive electrolyte (0.1 M NaCl, pH 2) concurrently with the oxygen evolution reaction (OER) in the transpassive region despite the absence of hysteresis in polarization curves or other obvious corrosion indicators. We present a characterization scheme to delineate the contribution of OER and alloy dissolution, using scanning electrochemical microscopy (SECM) for OER-onset detection, and quantitative chemical analysis with inductively coupled-mass spectrometry (ICP-MS) and ultraviolet visible light (UV-Vis) spectroscopy to elucidate metal dissolution processes. In-situ electrochemical atomic force microscopy (EC-AFM) revealed that the transpassive metal dissolution on CrCoNi is dominated by intergranular corrosion. These results have significant implications for the stability of MPEAs in corrosion systems, emphasizing the necessity of analytically determining metal ions released from MPEA electrodes into the electrolyte when evaluating Faradaic efficiencies of OER catalysts. The release of transition metal ions not only reduces the Faradaic efficiency of electrolyzers but may also cause poisoning and degradation of membranes in electrochemical reactors.
N2 - Multi-Hauptelement-Legierungen (MPEAs) gewinnen in der Korrosions- und Elektrokatalyseforschung aufgrund ihrer elektrochemischen Stabilität über einen breiten pH-Bereich und der Vielfalt der möglichen chemischen Zusammensetzungen zunehmend an Interesse. In unseren Untersuchungen mit der äquimolaren CrCoNi-Legierung in einem sauren Elektrolyten (0.1 M NaCl, pH 2) beobachteten wir eine signifikante Metallauflösung, die mit der Sauerstoffentwicklungsreaktion (OER) im transpassiven Bereich einhergeht, obwohl in zyklischen Polarisationskurven keine Hysterese auftrat oder andere offensichtliche Korrosionsindikatoren vorlagen. In diesem Artikel wird ein Charakterisierungskonzept eingeführt, dass die Beiträge der OER und der Legierungsauflösung differenziert. Hierfür kommt die elektrochemische Rastermikroskopie (SECM) zum Nachweis des Beginns der OER und die quantitative chemische Analyse mit induktiv gekoppelter Massenspektrometrie (ICP-MS) und UV/Vis-Spektrometrie zur Aufklärung der Metallauflösungsprozesse zum Einsatz. Die elektrochemische In situ-Atomkraftmikroskopie (EC-AFM) zeigte, dass die intergranulare Korrosion der dominierende Mechanismus der transpassive Metallauflösung von CrCoNi ist. Diese Ergebnisse besitzen erhebliche Auswirkungen für die Beurteilung der Stabilität von MPEAs in Korrosionssystemen und der Stromausbeute von OER-Katalysatoren auf der Basis von MPEAs. Die Daten unterstreichen die Notwendigkeit der analytischen Bestimmung von Metallionen, die von MPEA-Elektroden freigesetzt werden. Die Freisetzung von Übergangsmetallionen verringert nicht nur die Stromausbeute von Elektrolyseuren, sondern kann zu einer Schädigung von Membranen in elektrochemischen Reaktoren führen.
KW - Transpassive dissolution
KW - Corrosion
KW - Multi-prinicpal element alloys (MPEAs)
KW - Passivation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597045
DO - https://doi.org/10.1002/anie.202317058
SP - 1
EP - 8
PB - Wiley VHC-Verlag
AN - OPUS4-59704
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Czerski, Jakub
A1 - Mitoraj-Krolikowska, Marzena
A1 - Godlewska, Elzbieta
A1 - Wetzel, Annica
A1 - Witt, Julia
A1 - Ozcan, Ozlem
A1 - Marzec, Mateusz
A1 - Goly, Marcin
T1 - Corrosion and passivation of AlCrFe2Ni2Mox high-entropy alloys in sulphuric acid
N2 - Corrosion behaviour of AlCrFe2Ni2Mox (x = 0.0, 0.1, 0.15, 0.3 and 0.6) high-entropy alloys was investigated in a 0.1 M H2SO4 solution. Passive films formed upon anodic polarisation, built of Al-based inner layer and (Cr, Fe, Mo)-based outer layer, had good protective properties. In particular, they prevented corrosion of the (Al, Ni)-rich BCC-B2 phase, which was observed under open-circuit conditions. Moderate amounts of Mo, up to x = 0.3, positively affected the passivation ability of AlCrFe2Ni2. Significant changes in microstructure and phase composition of the alloy at higher Mo concentrations (x = 0.6) resulted in deterioration of its corrosion resistance.
KW - EIS
KW - Alloy
KW - Sulphuric acid
KW - AFM
KW - Acid corrosion
KW - Passive films
PY - 2024
DO - https://doi.org/10.1016/j.corsci.2024.111855
SN - 0010-938X
VL - 229
SP - 1
EP - 17
PB - Elsevier Ltd.
AN - OPUS4-59703
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, H.
A1 - Weidner, Steffen
A1 - Meyer, A.
T1 - Syntheses of Polyglycolide via Polycondensation: A Reinvestigation
N2 - The Na salt of chloroacetic acid is condensed in suspension. Furthermore,glycolic acid is condensed in bulk or in concentrated solution by means of SnCl2 or 4-toluene sulfonic acid (TSA) as catalysts. The temperatures are varied from 160 to 200°C and the time from 1 to 5 days. Low molar mass cyclic poly(glycolic acid) (PGA) is detected by means of matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry in most PGAs. A predominance of certain cycles having an even number of repeat units is observed suggesting a thermodynamically favored formation of extended-ring crystals. Extremely high melting temperatures (up to 237.5°C)and high melting enthalpies are found for polycondensations with TSA in 1,2-dichlorobenzene.
KW - MALDI TOF MS
KW - Polycondensation
KW - Polyglycolide
KW - Cyclization
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596856
DO - https://doi.org/10.1002/macp.202300397
IS - 2300397
SP - 1
EP - 7
PB - Wiley VHC-Verlag
AN - OPUS4-59685
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Emamverdi, Farnaz
A1 - Huang, J.
A1 - Szymoniak, Paulina
A1 - Bojdys, M. J.
A1 - Böhning, Martin
A1 - Schönhals, Andreas
T1 - Structure and molecular mobility of phosphinine-based covalent organic frameworks – glass transition of amorphous COFs
N2 - Two-dimensional covalent organic frameworks (COFs) based on phosphinine and thiophene building blocks have been synthesized with two different side groups. The materials are denoted as CPSF-MeO and CPSF-EtO where CxxF correspond to the covalent framework, whereas P and S are related to heteroatoms phosphorous and sulfur. MeO and EtO indicate the substituents, i.e. methoxy and ethoxy.
Their morphologies were studied by scanning electron microcopy and X-ray scattering. The absence of crystalline reflexes in the X-ray pattern reveal that both materials are amorphous and can be considered as glasses. Furthermore, N2 adsorption measurements indicate substantial Brunauer–Emmett–Teller (BET) surface area values pointing to the formation of three-dimensional pores by stacking of the aromatic 2D layer. An analysis of the porosity of both COFs showed a mean radius of the pores to be of ca. 4 nm, consistent with their chemical structure. The COFs form nanoparticles with a radius of around 100 nm. The thermal behavior of the COFs was further investigated by fast scanning calorimetry. These investigations showed that both COFs undergo a glass transition. The glass transition temperature of CPSF-EtO is found to be ca. 100 K higher than that for CPSF-MeO. This large difference in the glass transition is discussed to be due to a change in the interaction of the COF sheets induced by the longer ethoxy group. It might be assumed that for CPSF-EtO more individual COF sheets assemble to larger stacks than for CPSF-MeO. This agrees with the much larger surface area value found for CPSF-EtO compared to CPSF-MeO. To corroborate the results obtained be fast scanning calorimetry dielectric measurements were conducted which confirm the occurrence of a dynamic glass transition. The estimated temperature dependence of the relaxation rates of the dielectric relaxation and their absolute values agrees well with the data obtained by fast scanning calorimetry. Considering the fragility approach to the glass transition, it was further found that CPSF-MeO is a fragile glass former whereas CPSF-EtO behaves as a strong glass forming material. This difference in the fragility points also to distinct differences in the interaction between the 2D COF molecules in both materials.
KW - Covalent Organic frameworks
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596770
DO - https://doi.org/10.1039/d3ma01123b
SP - 1
EP - 10
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59677
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Bonse, Jörn
T1 - Funktionalisierung durch laser-induzierte periodische Oberflächenstrukturen
N2 - Der Vortrag gibt einen Überblick über die vielfältigen Möglichkeiten der Oberflächenfunktionalisierung mittels Mikro- und Nanostrukturierung durch Ultrakurzpuls-Lasermaterialbeabeitung. Dies schließt eine Diskussion des Phänomens der Laser-induzierten periodischen Oberflächenstrukturen (LIPSS, engl.: Laser-induced Periodic Surface Structures, Ripples), sowie deren Klassifikation und Bildungsmechanismen mit ein. Ein Schwerpunkt der Präsentation liegt auf der Diskussion verschiedener Anwendungsmöglichkeiten der LIPSS in Bereichen der Optik, Fluidik, Tribologie und Medizin, sowie auf einem Ausblick auf die industrielle Skalierbarkeit der LIPSS-Technologie.
T2 - 1. Netzwerktreffen 2024 des UKPL-Innovationsnetzwerks
CY - Rostock, Germany
DA - 11.03.2024
KW - Laser-induced Periodic Surface Structures (LIPSS)
KW - Oberflächenfunktionalisierung
KW - Mikrostrukturen
KW - Nanostrukturen
KW - Ultrakurzpuls-Laserbearbeitung
PY - 2024
AN - OPUS4-59657
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Heinekamp, Christian
A1 - Guiherme Buzanich, Ana
A1 - Ahrens, Mike
A1 - Emmerling, Franziska
A1 - Braun, Thomas
T1 - Zirconium chloro fluoride as catalyst for C-F bond activation and HF transfer of fluoroalkanes
N2 - In this work1, we have successfully synthesised amorphous zirconium chloro fluoride (ZCF), which exhibits medium lewis acidity. In addition to investigating the local coordination sphere around the Zr atoms and the material properties, we were able to establish a catalytic behavior of ZCF in C-F bond activation reactions. We present the first heterogeneous catalyst that performs dehydrofluorination of a fluoroalkane and consecutive hydrofluorination of an alkyne at room temperature.
T2 - RSC Poster 2024
CY - Online meeting
DA - 05.03.2024
KW - ZCF
PY - 2024
AN - OPUS4-59619
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Pauw, Brian Richard
A1 - Hörmann, Anja
T1 - Trinamic TMCL IOC for exposing Trinamics motor controllers to EPICS CA
N2 - Trinamic TMCL IOC is a Python package designed for controlling stepper motors connected to a Trinamic board using the TMCL language (all boards supported by PyTrinamic should now work, has been tested on the TMCM 6110 and the TMCM 6214). Since it is implementing the TMCL protocol, it should be easy to adapt to other Trinamic motor controller boards. This package assumes the motor controller is connected over a machine network via a network-to-serial converter, but the underlying PyTrinamic package allows for other connections too.
This allows the control of attached motors via the EPICS Channel-Access virtual communications bus. If EPICS is not desired, plain Pythonic control via motion_control should also be possible. An example for this will be provided in the example.ipynb Jupyter notebook.
This package leverages Caproto for EPICS IOCs and a modified PyTrinamic library for the motor board control, and interfaces between the two via an internal set of dataclasses. Configuration for the motors and boards are loaded from YAML files (see tests/testdata/example_config.yaml).
The modifications to PyTrinamic involved extending their library with a socket interface. This was a minor modification that should eventually find its way into the official package (a pull request has been submitted).
KW - Instrumentation
KW - Motor controller
KW - EPICS
KW - Channel access
KW - Instrument control
KW - Laboratory automation
PY - 2024
DO - https://doi.org/10.5281/zenodo.10792593
PB - Zenodo
CY - Geneva
AN - OPUS4-59624
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Otremba, Frank
A1 - An, Q.
A1 - Bäßler, Ralph
A1 - Hertwig, Andreas
A1 - Rehfeldt, Rainer
A1 - Hidde, Gundula
T1 - Investigation of mechanical stress and B10 exposure on FKM polymer
N2 - Biofuels, particularly biodiesel, have gained significant attention as an alternative to traditional fossil fuels in recent years. Unlike diesel, which contains hundreds of compounds, biodiesel only contains a few compounds in the C16-C18 carbon chain. However, the use of biodiesel in automobile and transportation applications can result in problems of degradation or even damage in materials. Among the commonly used polymer materials, fluorocarbon (FKM) shows excellent performance and high stability and compatibility towards oil, diesel, ethanol, and other chemicals. FKM is a family of fluorocarbon-based fluoroelastomer materials, which provide excellent high-temperature and chemical stability compared to other elastomers. As a result, FKM is widely used in chemical processes such as petroleum refining, where it is used for sealings, pumps, and other components.
T2 - TMS 2024 153rd Annual Meeting & Exhibition Supplemental Proceedings
CY - Orlando, Florida, USA
DA - 03.03.2024
KW - B10 exposure
KW - FKM polymer
PY - 2024
AN - OPUS4-59636
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Omar, Hassan
A1 - Szymoniak, Paulina
A1 - Hertwig, Andreas
A1 - Schönhals, Andreas
T1 - Investigations of Ultrathin Polymer Films Supported on Inorganic Substrates
N2 - Interactions between a polymer and a substrate interface play a vital role in understanding the improvement in thin film material properties as well as serving as a model for nanocomposites. For any non-repulsive polymer-substrate interactions, polymer segments form an irreversibly adsorbed layer and show a slowdown in the glassy dynamics and thus an increase in the thermal glass transition temperature compared to the bulk-like values. The growth kinetics of the adsorbed layer showed a deviation for both poly (bisphenol-A carbonate) (PBAC) and polysulfone (PSU), two bulky polymers containing a functional group (phenyl ring) in the backbone.
T2 - Royal Society of Chemistry (RSC) Online Poster Conference
CY - Online meeting
DA - 05.03.2024
KW - Adsorbed Layer
KW - Thin Films
KW - Atomic Force Microscopy
KW - Ellipsometry
PY - 2024
AN - OPUS4-59625
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pauw, Brian Richard
T1 - The Dark Side of Science (2024 edition)
N2 - This presentation highlights ongoing scientific misconduct as found in academic literature. This includes data- and image manipulation, and paper mills. Starting with an expose of examples, it delves deeper into the causes and metrics driving this phenomenon. Finally a range of possible tools is presented, that the young researcher can use to prevent themselves from sliding into the dark scientific methods.
T2 - Winter School on Metrology and Nanomaterials for Clean Energy
CY - Claviere, Italy
DA - 28.01.2024
KW - Scientific misconduct
KW - Data manipulation
KW - Image manipulation
KW - Paper mills
KW - Causes leading to scientific misconduct
KW - Tools to combat scientific misconduct
KW - Metrics
PY - 2024
AN - OPUS4-59622
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pauw, Brian Richard
T1 - Glimpses of the future: Systematic investigations of 1200 mofs using a highly automated, full-stack materials research laboratory
N2 - By automatically recording as much information as possible in automated laboratory setups, reproducibility and traceability of experiments are vastly improved. This presentation shows what such an approach means for the quality of experiments in an X-ray scattering laboratory and an automated synthesis set-up.
T2 - Winter School on Metrology and Nanomaterials for Clean Energy
CY - Claviere, Italy
DA - 28.01.2024
KW - Digitalization
KW - Automation
KW - Digital laboratory
KW - Scattering
KW - Synthesis
KW - Nanomaterials
KW - Holistic science
PY - 2024
AN - OPUS4-59621
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Heinekamp, Christian
A1 - Guiherme Buzanich, Ana
A1 - Kneiske, Sönke
A1 - Ahrens, Mike
A1 - Braun, Thomas
A1 - Emmerling, Franziska
T1 - A fluorolytic sol-gel route to access an amorphous Lewis-acidic Zr fluoride catalyst
N2 - Kemnitz et al. developed a fluorolytic route to access metal fluorides 2 such as AlF3 3 and MgF2 4 which possess a high surface area. In aluminium-based systems, the synthetic approach led to amorphous xerogels that can be further converted into Lewis superacids.3 Still, despite zirconium oxide being described as a stronger Lewis acid than other metal oxides 4 zirconium fluoride-based materials have only recently been reported or investigated. 6 In this work we extend the class of amorphous Lewis acidic heterogeneous catalysts to an amorphous ZrF4 that is active in C-F bond activation.
T2 - 2nd South African Fluorine Symposium
CY - Sun City, South Africa
DA - 11.02.2024
KW - ZrF4
KW - Heterogeneous catalysis
KW - C-F bond activation
PY - 2024
AN - OPUS4-59617
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - An, Q.
A1 - Bäßler, Ralph
A1 - Hertwig, Andreas
A1 - Rehfeldt, Rainer
A1 - Hidde, Gundula
A1 - Otremba, Frank
T1 - Investigation of Mechanical Stress and B10 Exposure on FKM Polymer
N2 - Mechanical stress often accelerates the failure of polymer materials. The aim of this research is to study the interaction between the sealing material FKM and biofuels B10 (heating oil with 10% biodiesel). The mechanical stress test was carried out in a special apparatus. Both mechanical and non-mechanical stress tests were conducted on specimens at 20, 40, and 70 °C for 28 days to document changes in mass, volume, and tensile properties. Both increasing temperature and mechanical stress have a significant effect on the tensile strength of the FKM polymer when exposed to B10. The combination of increasing temperature and mechanical stress induced rupture within 2 h. It was also established that FKM polymer with pre-exposure in B10 survived longer during mechanical stress compared to specimens exposed only to air. With the support of infrared (IR) spectroscopy, we were able to confirm the penetration of B10 into the FKM polymer.
T2 - TMS 2024 Annual Meeting & Exhibition Teilnahme mit Präsentation
CY - Orlando-Florida / USA
DA - 03.03.2024
KW - Biofuels
KW - Sealing materials
KW - Mechanical stress
KW - Change in tensile properties
PY - 2024
DO - https://doi.org/10.1007/978-3-031-50349-8_108
SP - 1253
EP - 1261
PB - Springer
CY - Orlando-Florida / USA
AN - OPUS4-59638
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hodoroaba, Vasile-Dan
T1 - Delivering Impact - A new ISO standard on the identification of nanoparticles
N2 - Nanoparticles (NPs) are tiny – around 1 to 100 billionths of a meter – and can have different chemistries and behaviours than the same material of larger size. This property has led to advances in a wide range of industries, but it can also confer toxicity. Size measurements are the main way NPs are identified but a lack of standardised methods for identifying ones with complex shapes has hindered evaluation of their potential harm.
KW - Nanoparticles
KW - Standardisation
KW - Particle size distribution
KW - nPSize
KW - ISO 21363
PY - 2024
UR - https://www.euramet.org/casestudies/casestudiesdetails/news/default-c3b26209e8
SP - 1
EP - 2
PB - EURAMET
CY - Braunschweig
AN - OPUS4-59626
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Heinekamp, Christian
A1 - Guiherme Buzanich, Ana
A1 - Kneiske, Sönke
A1 - Ahrens, Mike
A1 - Braun, Thomas
A1 - Emmerling, Franziska
T1 - EXAFS elucidating local structure of zirconium based aorphous heterogeneous catalysts in C-F bond activation
N2 - Amorphous materials play an important role in C-F bond activation but face the difficulty of limited available structural information by methods such as powder XRD and solid-state MAS NMR spectroscopy especially if the nucleus is not abundant enough. Here, we present heterogeneous catalysts, active in C-F bond activation, where EXAFS allowed specifically elucidating the local structure, which would have not been possible elsewise.
T2 - HZB User Meeing 2023
CY - Berlin, Germany
DA - 22.06.2023
KW - Catalysis
KW - Zirconium
KW - C-F bond activation
PY - 2023
AN - OPUS4-59615
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Bonse, Jörn
A1 - Schwibbert, Karin
A1 - Richter, Anja M.
A1 - Krüger, Jörg
T1 - Laserstrukturierte Oberflächen Ein Weg zur Kontrolle der Biofilmbildung?
N2 - Bakterielle Biofilme stellen in medizinischen und industriellen Bereichen ein ernsthaftes Problem dar. Eine der größten gesellschaftlichen Herausforderungen liegt in der zunehmenden Resistenz von Bakterien gegen Biozide, die bei antimikrobiellen Behandlungen eingesetzt werden, z.B. durch übermäßigen Einsatz in Medizin, Industrie und Landwirtschaft oder durch Reinigung und Desinfektion in Privathaushalten. Daher sind neue effiziente bakterienabweisende Strategien, die den Einsatz von Bioziden vermeiden, dringend erforderlich.
Ein vielversprechender Weg zur Erzielung bakterienabweisender Oberflächen liegt in der berührungslosen und aseptischen großflächigen Laserbearbeitung von technischen Oberflächen. Maßgeschneiderte Oberflächentexturen, ermöglicht durch verschiedene Laserbearbeitungsstrategien, die zu topographischen Skalen im Bereich von Nanometern bis Mikrometern führen, können eine Lösung für diese Herausforderung darstellen.
In dem Vortrag wird ein Überblick über den aktuellen Stand der Technik bei der subtraktiven Texturierung von Laseroberflächen zur Kontrolle der Biofilmbildung bei verschiedenen Bakterienstämmen und in unterschiedlichen Umgebungen gegeben. Auf der Grundlage spezifischer Eigenschaften von Bakterien und laserbearbeiteten Oberflächen werden die Herausforderungen antimikrobieller Oberflächendesigns erörtert und zukünftige Richtungen aufgezeigt.
T2 - GRAVOSeminar, GRAVOmer Kompetenznetzwerk
CY - Online meeting
DA - 28.02.2024
KW - Laser-Materialbearbeitung
KW - Ultrakurzpuls-Laser
KW - Biofilme
KW - Antibakterielle Oberflächen
KW - Oberflächenfunktionalisierung
PY - 2024
UR - https://gravomer.de/veranstaltungen-anzeigen/laserstrukturierte-oberflaechen-ein-weg-zur-kontrolle-der-biofilmbildung
AN - OPUS4-59594
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radnik, Jörg
T1 - How to perform reliable xps-measurements?
N2 - Reliable measurements are a great challenge in X-ray photoelectron spectroscopy. It will be shown, how to check the performance and calibration of the instrument, the charge compensation, quantification, fitting, and depth profiling.
T2 - Course for PhD students at SFB 1073
CY - Göttingen, Germany
DA - 23.02.2024
KW - X-ray photoelectron spectroscopy
KW - Reproducibility crisis
KW - Reliability
PY - 2024
AN - OPUS4-59590
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radnik, Jörg
A1 - Stockmann, Jörg Manfred
A1 - Knigge, Xenia
A1 - Chemello, Giovanni
A1 - Hodoroaba, Vasile-Dan
A1 - Resch-Genger, Ute
A1 - Madkour, S.
A1 - Schönhals, Andreas
A1 - Reed, B.
A1 - Clifford, C.
A1 - Shard, A.
T1 - (hard) x ray photoelectron spectroscopy as tool in nano-analytics
N2 - Selected samples are used to show, that photoelectron spectroscopy is an important tool for measuring nano-objects, especially for determing the chemical composition and structure on the nanosacle. XPS with different energies offers new possibilities in depth-profiling.
T2 - SFB 1073 Colloquium
CY - Göttingen, Germany
DA - 22.02.2024
KW - X-ray photoelectron spectroscopy
KW - Core-shell nanoparticle
KW - Graphene related 2D materials
PY - 2024
AN - OPUS4-59589
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Naik, Aakash Ashok
A1 - Ueltzen, Katharina
A1 - Ertural, Christina
A1 - Jackson, Adam J.
A1 - George, Janine
T1 - LobsterPy: A package to automatically analyze LOBSTERruns
N2 - The LOBSTER (Deringer et al., 2011;Maintz et al., 2013 ,2016 ;Nelson et al., 2020 ) software aids in extracting quantum-chemical bonding information from materials by projecting the plane-wave based wave functions from density functional theory (DFT) onto an atomic orbital basis. LobsterEnv, a module implemented in pymatgen (Ong et al., 2013) by some of the authors of this package, facilitates the use of quantum-chemical bonding information obtained from LOBSTER calculations to identify neighbors and coordination environments. LobsterPy is a Python package that offers a set of convenient tools to further analyze and summarize the LobsterEnv outputs in the form of JSONs that are easy to interpret and process. These tools enable the estimation of (anti) bonding contributions, generation of textual descriptions, and visualization of LOBSTER computation results. Since its first release, both LobsterPy and LobsterEnv capabilities have been extended significantly. Unlike earlier versions, which could only automatically analyze Crystal Orbital Hamilton Populations (COHPs) (Dronskowski & Blöchl, 1993), both can now also analyze Crystal Orbital Overlap Populations (COOP) (Hughbanks & Hoffmann, 1983) and Crystal Orbital Bond Index (COBI) (Müller et al., 2021). Extracting the information about the most important orbitals contributing to the bonds is optional, and users can enable it as needed. Additionally, bonding-based features for machinelearning (ML) studies can be engineered via the sub-packages “featurize” and “structuregraphs”. Alongside its Python interface, it also provides an easy-to-use command line interface (CLI) that runs automatic analysis of the computations and generates a summary of results and publication-ready figures. LobsterPy has been used to produce the results in Ngo et al. (2023), Chen et al. (2024), Naik et al. (2023), and it is also part of Atomate2 (2023) bonding analysis workflow for generating bonding analysis data in a format compatible with the Materials Project (Jain et al., 2013) API.
KW - Materials Science
KW - Automation
KW - Bonding Analysis
KW - Materials Properties
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595809
DO - https://doi.org/10.21105/joss.06286
VL - 9
IS - 94
SP - 1
EP - 4
PB - The Open Journal
AN - OPUS4-59580
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Bonse, Jörn
T1 - Erzeugung und Charakterisierung anisotroper Nanostrukturen durch Ultrakurzpulslaser
N2 - Der Vortrag gibt einen Überblick über die Erzeugung und Charakterisierung anisotroper Nanostrukturen mittels ultrakurzgepulster Laserstrahlung. Besonderes Augenmerk liegt dabei auf dem Phänomen der sogenannten Laser-induzierten periodischen Oberflächen-Nanostrukturen auf dielektrischen Werkstoffen und ihrer zeitlichen Dynamik. Weitere Beispiele von Volumen-Nanostrukturen aus der Literatur werden diskutiert.
T2 - 21. Treffen des DGG-DKG Arbeitskreises „Glasig-kristalline Multifunktionswerkstoffe“
CY - Mainz, Germany
DA - 22.02.2024
KW - Laser-induzierte periodische Oberflächen-Nanostrukturen
KW - Quarzglas
KW - Saphir
KW - Bessel-Strahlen
PY - 2024
AN - OPUS4-59565
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Data-driven chemical understanding with bonding analysis
N2 - Bonds and local atomic environments are crucial descriptors of material properties. They have been used to create design rules and heuristics and as features in machine learning of materials properties. Implementations and algorithms (e.g., ChemEnv and LobsterEnv) for identifying local atomic environments based on geometrical characteristics and quantum-chemical bonding analysis are nowadays available. Fully automatic workflows and analysis tools have been developed to use quantum-chemical bonding analysis on a large scale. The lecture will demonstrate how our tools, that assess local atomic environments and perform automatic bonding analysis, help to develop new machine learning models and a new intuitive understanding of materials.[5,6] Furthermore, the general trend toward automation in density functional-based materials science and some of our recent contributions will be discussed.
T2 - Seminar of the Department of Chemistry at Imperial College London
CY - Online meeting
DA - 20.02.2024
KW - Automation
KW - Magnetism
KW - Bonding Analysis
KW - Machine Learning
PY - 2024
AN - OPUS4-59546
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - RPRT
A1 - Bartczack, Dorota
A1 - Taché, Olivier
A1 - Hodoroaba, Vasile-Dan
T1 - Report on the homogeneity assessment of bimodal gold materials (nPSize1 and nPSize2) and particle number concentration by frequency method
N2 - The main objective was to assess homogeneity of two bimodal gold materials, namely nPsize1 and nPSize2, containing approximately 1:1 and 10:1 particle number-based ratio of ~30nm and ~60nm particles. Particle number-based concentration within the two size fractions was determined with spICP-MS using the particle frequency method of calibration.
KW - Nanoparticles
KW - Homogeneity
KW - Particle number concentration
KW - Gold
KW - nPSize
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595451
DO - https://doi.org/10.5281/zenodo.10654245
SP - 1
EP - 5
PB - Zenodo
CY - Geneva
AN - OPUS4-59545
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weidner, Steffen
A1 - Meyer, A.
A1 - Kricheldorf, H.
T1 - Cyclic polyglycolides via ring-expansion polymerization with cyclic tin catalysts
N2 - Glycolide was polymerized in bulk with two cyclic catalysts − 2,2-dibutyl-2-stanna-1,3-dithiolane (DSTL) and 2-stanna-1,3-dioxa-4,5,6,7-dibenzepane (SnBiph). The monomer/initiator ratio, temperature (140 – 180 °C) and time (1–––4 days) were varied. The MALDI TOF mass spectra exclusively displayed peaks of cyclic polyglycolide (PGA) and revealed an unusual “saw-tooth pattern” in the mass range below m/z 2 500 suggesting formation of extended ring crystallites. The DSC measurements indicated increasing crystallinity with higher temperature and longer time, and after annealing for 4 d at 160 °C a hitherto unknown and unexpected glass transition was found in the temperature range of 170–185 °C. Linear PGAs prepared by means of metal alkoxides under identical conditions did not show the afore-mentioned features of the cyclic PGAs, neither in the mass spectra nor in the DSC measurements. All PGAs were also characterized by SAXS measurements, which revealed relatively small L-values suggesting formation of thin crystallites in all cases with little influence of the reaction conditions.
KW - Polyglycolide
KW - MALDI-TOF MS
KW - Ring-expansion polymerization
KW - Crystals
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595541
DO - https://doi.org/10.1016/j.eurpolymj.2024.112811
SN - 0014-3057
VL - 207
SP - 1
EP - 9
PB - Elsevier Ltd.
AN - OPUS4-59554
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Manoharan, Deepak
A1 - Ranjan, Subham
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
A1 - Takamizawa, Satoshi
A1 - Ghosh, Soumyajit
T1 - Elasto-plastic behaviour with reversible thermosalient expansion in acrylonitrile-based organic crystals
N2 - Crystalline materials that exhibit reversible mechanical responses upon exposure to external stimuli have garnered significant attention owing to their potential applications in various fields. Herein, we report a crystal of (2Z,2′Z)-2,2′-(1,4-phenylene)bis(3-(4-bromophenyl)acrylonitrile) (DSBr), which displays simultaneous elasto-plastic behaviour and reversible thermosalient effects. While elasto-plastic behaviour is attributed to underlying packing features, reversible thermosalient expansion is attributed to uniaxial expansion mediated by heat. Exceptional length increase and contraction upon cooling is due to the restorative nature of weak interactions through a cooperative effect. The cooperative movement of molecules is reflected in the unidirectional expansion of the habit plane. Thermosalient reversible expansion–contraction in elasto-plastic crystals have not been discussed in the literature so far. Detailed analysis reported herein provides a comprehensive understanding of the underlying mechanism of flexibility and thermosalient responses. This crystal's unique blend of reversible thermal expansion with flexibility holds substantial promise for applications in flexible thermal actuators.
KW - Materials Chemistry
KW - General Chemistry
PY - 2024
DO - https://doi.org/10.1039/D3TC04272C
SN - 2050-7526
SP - 1
EP - 11
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59527
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bonse, Jörn
A1 - Sokolowski‐Tinten, Klaus
T1 - Probing Laser‐Driven Structure Formation at Extreme Scales in Space and Time
N2 - Irradiation of solid surfaces with high intensity, ultrashort laser pulses triggers a variety of secondary processes that can lead to the formation of transient and permanent structures over a large range of length scales from mm down to the nano‐range. One of the most prominent examples are LIPSS – Laser‐Induced Periodic Surface Structures. While LIPSS have been a scientific evergreen for of almost 60 years, experimental methods that combine ultrafast temporal with the required nm spatial resolution have become available only recently with the advent of short pulse, short wavelength free electron lasers. Here, the current status and future perspectives in this field are discussed by exploiting the unique possibilities of these 4th‐generation light sources to address by time‐domain experimental techniques the fundamental LIPSS‐question, namely why and how laser irradiation can initiate the transition of a “chaotic” (rough) surface from an aperiodic into a periodic structure.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Free electron laser
KW - Pump-probe experiments
KW - Time-resolved scattering
KW - Capillary waves
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595048
DO - https://doi.org/10.1002/lpor.202300912
SN - 1863-8899
VL - 18
SP - 1
EP - 11
PB - Wiley-VCH GmbH
CY - Weinheim
AN - OPUS4-59504
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Emamverdi, Farnaz
A1 - Huang, J.
A1 - Mosane Razavi, Negar
A1 - Bojdys, M. J.
A1 - Forster, A. B.
A1 - Budd, P. M.
A1 - Böhning, Martin
A1 - Schönhals, Andreas
T1 - Molecular Mobility and Gas Transport Properties of Mixed Matrix Membranes Based on PIM‑1 and a Phosphinine Containing Covalent Organic Framework
N2 - Polymers with intrinsic microporosity (PIMs) are gaining attention as gas separation membranes. Nevertheless, they face limitations due to pronounced physical aging. In this study a covalent organic framework containing λ5-phosphinine moieties, CPSF-EtO were incorporated as a nanofiller (concentration range 0-10 wt%) into a PIM-1 matrix forming dense films with a thickness of ca. 100 μm. The aim of the investigation was to investigate possible enhancements of gas transport properties and mitigating effects on physical aging. The incorporation of the nanofiller occurred on aggregate level with domains up to 100 nm as observed by T-SEM and confirmed by X-ray scattering. Moreover, the X-ray data show that the structure of the microporous network of the PIM-1 matrix is changed by the nanofiller.
As the molecular mobility is fundamental for gas transport as well as for physical aging, the study includes dielectric investigations of pure PIM-1 and PIM-1/CPSF-EtO mixed matrix membranes to establish a correlation between the molecular mobility and the gas transport properties. Using the time-lag method the gas permeability and the permselectivity were determined for N2, O2, CH4 and CO2 for samples with variation in filler content. A significant increase in the permeability of CH4 and CO2 (50 % increase compared to pure PIM-1) was observed for a concentration of 5 wt% of the nanofiller. Furthermore, the most pronounced change in the permselectivity was found for the gas pair CO2/N2 at a filler concentration of 7 wt%.
KW - Polymers of Intrinsic Microporosity
KW - Nanocomposites
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595031
DO - https://doi.org/10.1021/acs.macromol.3c02419
SN - 0024-9297
VL - 57
IS - 4
SP - 1829
EP - 1845
PB - ACS Publications
AN - OPUS4-59503
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radnik, Jörg
T1 - Graphene Flagship - Achievements and the way forward
N2 - The activities of the Graphene in the field of standardization will be summarized. The future activities of the Graphene Flagship CSA which was established recently will be presented with the focus on future challenges in standardization and regulation of graphene and other 2D materials.
T2 - Harmonisation & Standardisation of Test Methods for Nano- and Advanced Materials
CY - Online meeting
DA - 22.11.2023
KW - 2D materials
KW - Regulation
KW - Standardization
PY - 2023
UR - https://macrame-project.eu/macrame-meetings-workshops/ws_hamonisation_standardisation_2023/
AN - OPUS4-59497
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radnik, Jörg
T1 - Xps/Haxpes at (core shell) nanoparticles
N2 - The principles of (Hard) X-ray photoelectron spectroscopy and some application in the field of (core-shell) nanoparticles will be presented. The presentation should answer hoe to get reliable results. Furthermore, examples of the correlation between physical-chemical measurments and toxicological results are given which are crucial for the risk assessment of nanoparticles.
T2 - Training Course Metrological Determination of Micro and Nano Contaminants in Food
CY - Berne, Switzerland
DA - 05.09.2023
KW - X-ray photoelectron spectroscopy
KW - Core-shell nanoparticles
KW - Reliabiilty
KW - Risk assessment
PY - 2023
AN - OPUS4-59496
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zuffa, Caterina
A1 - Cappuccino, Chiara
A1 - Casali, Lucia
A1 - Emmerling, Franziska
A1 - Maini, Lucia
T1 - Liquid reagents are not enough for liquid assisted grinding in the synthesis of (AgBr)(n-pica) n
N2 - This study investigates the mechanochemical reactions between AgBr 3-picolylamine and 4-picolylamine. The use of different stoichiometry ratios of the reagents allows [(AgBr)(n-pica)]n and [(AgBr)2(n-pica)]n to be obtained, and we report the new structures of [(AgBr)2(3-pica)]n and [(AgBr)2(4-pica)]n which are characterized by the presence of the following: (a) infinite inorganic chains, (b) silver atom coordinated only by bromide atoms and (c) argentophilic interactions. Furthermore, we studied the interconversion of [(AgBr)(n-pica)]n/[(AgBr)2(n-pica)]n by mechanochemical and thermal properties. The in situ experiments suggest that [(AgBr)(3-pica)]n is kinetically favoured while [(AgBr)2(3-pica)]n is converted into [(AgBr)(3-pica)]n only with a high excess of the ligand. Finally, the liquid nature of the ligands is not sufficient to assist the grinding process, and the complete reaction is observed with the addition of a small quantity of acetonitrile.
KW - Mechanochemistry
KW - Complex
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594755
DO - https://doi.org/10.1039/d3cp04791a
SN - 1463-9076
SP - 1
EP - 10
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stawski, Tomasz
A1 - Karafiludis, Stephanos
A1 - Pimentel, Carlos
A1 - Montes-Hernández, German
A1 - Kochovski, Zdravko
A1 - Bienert, Ralf
A1 - Weimann, Karin
A1 - Emmerling, Franziska
A1 - Scoppola, Ernesto
A1 - Van Driessche, Alexander E.S.
T1 - Solution-driven processing of calcium sulfate: The mechanism of the reversible transformation of gypsum to bassanite in brines
N2 - Here, we show that calcium sulfate dihydrate (gypsum) can be directly, rapidly and reversibly converted to calcium sulfate hemihydrate (bassanite) in high salinity solutions (brines). 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 better-known behaviour of the bassanite phase in low-salt environments. In low-salinity aqueous solutions, bassanite is considered to be metastable with respect to gypsum and anhydrite, and therefore gypsum-to-bassanite conversion does not occur in pure water. Interestingly, the high-salinity transformation of gypsum-to-bassanite has been reported by many authors and used in practice for several decades, although 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 was 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 phase for many hours before reverting into gypsum. This property is extremely advantageous for practical processing and efficient crystal extraction in industrial scenarios.
KW - Industrial and Manufacturing Engineering
KW - Strategy and Management
KW - General Environmental Science
KW - Renewable Energy, Sustainability and the Environment
KW - Building and Construction
KW - Calcium sulfate
KW - Gypsum
KW - Bassanite
KW - Scattering
KW - Raman
KW - In situ
KW - Synchrotron
KW - BESSY
KW - MySpot
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594698
UR - https://www.sciencedirect.com/science/article/pii/S0959652624004591#appsec1
DO - https://doi.org/10.1016/j.jclepro.2024.141012
SN - 0959-6526
VL - 440
SP - 1
EP - 12
PB - Elsevier B.V.
AN - OPUS4-59469
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -