TY - JOUR
A1 - Bruna, F. G.
A1 - Prokop, M.
A1 - Bystron, T.
A1 - Loukrakpam, R.
A1 - Melke, J.
A1 - Lobo, C. M. S.
A1 - Fink, M.
A1 - Zhu, M.
A1 - Voloshina, E.
A1 - Kutter, M.
A1 - Hoffmann, H.
A1 - Yusenko, Kirill
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, B.
A1 - Bouzek, K.
A1 - Paulus, B.
A1 - Roth, C.
T1 - Following adsorbed intermediates on a platinum gas diffusion electrode in H3PO3‑containing electrolytes using in situ X‑ray absorption spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalyst with H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - Δμ XANES
KW - H3PO3
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - ACS
CY - Washington, DC
AN - OPUS4-55815
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gomes, Bruna F.
A1 - Prokop, Martin
A1 - Bystron, Tomas
A1 - Loukrakpam, Rameshwori
A1 - Melke, Julia
A1 - Lobo, Carlos M. S.
A1 - Fink, Michael
A1 - Zhu, Mengshu
A1 - Voloshina, Elena
A1 - Kutter, Maximilian
A1 - Hoffmann, Hendrik
A1 - Yusenko, Kirill V.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, Bettina
A1 - Bouzek, Karel
A1 - Paulus, Beate
A1 - Roth, Christina
T1 - Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using In Situ X-ray Absorption Spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalystwith H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate Proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - H3PO3,
KW - Δμ XANES
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - American Chemical Society (ACS)
AN - OPUS4-64733
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Martins, Ines
A1 - Al-Sabbagh, Dominik
A1 - Bentrup, U.
A1 - Marquardt, Julien
A1 - Schmid, Thomas
A1 - Scoppola, E.
A1 - Kraus, Werner
A1 - Stawski, Tomasz
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Yusenko, Kirill
A1 - Weidner, Steffen
A1 - Emmerling, Franziska
T1 - Formation Mechanism of a Nano-Ring of Bismuth Cations and Mono-Lacunary Keggin-Type Phosphomolybdate
N2 - A new hetero-bimetallic polyoxometalate (POM) nano-ring was synthesized in a one-pot procedure. The structure consists of tetrameric units containing four bismuth-substituted monolacunary Keggin anions including distorted [BiO8] cubes. The nano-ring is formed via self-assembly from metal precursors in aqueous acidic medium. The compound (NH4)16[(BiPMo11O39)4] ⋅ 22 H2O; (P4Bi4Mo44) was characterized by single-crystal X-ray diffraction, extended X-ray absorption fine structure spectroscopy (EXAFS), Raman spectroscopy, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF), and thermogravimetry/differential scanning calorimetry mass spectrometry (TG-DSC-MS). The formation of the nano-ring in solution was studied by time-resolved in situ small- and wide-angle X-ray scattering (SAXS/WAXS) and in situ EXAFS measurements at the Mo−K and the Bi−L3 edge indicating a two-step process consisting of condensation of Mo-anions and formation of Bi−Mo-units followed by a rapid self-assembly to yield the final tetrameric ring structure.
KW - Bismuth
KW - In situ EXAFS
KW - In situ SAXS/WAXS
KW - Lacunary Keggin ion
KW - Polyoxometalates
KW - Self-assembly
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546823
DO - https://doi.org/10.1002/chem.202200079
SN - 0947-6539
VL - 28
IS - 27
SP - 1
EP - 7
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54682
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
T1 - Forschungsprogramm 2022 - 2024
N2 - Der Koalitionsvertrag der Bundesregierung betont in seiner Präambel zur Zukunft Deutschlands in Bezug auf die notwendige Modernisierung, dass „dieser Fortschritt auch mit einem Sicherheitsversprechen einhergehen muss“. Die Bundesanstalt für Materialforschung und -prüfung (BAM) stellt mit ihrem Auftrag „Sicherheit in Technik und Chemie“ und ihrer über 150-jährigen Kompetenz sicher, dass ein nachhaltiger technischer Fortschritt von einem Sicherheitsversprechen für die Bürger*innen begleitet ist.
Durch ihre Interdisziplinarität, die thematische Breite, die langjährige Erfahrung und die unabhängige Rolle als Ressortforschungseinrichtung ist die BAM in einer herausragenden Lage, als zentraler Akteur die Entwicklung unterschiedlichster Technologien unter Berücksichtigung sicherheitstechnischer Aspekte voranzubringen, das Vertrauen der Gesellschaft in diese Technologien sicherzustellen und dadurch die Basis für erfolgreiche Innovationen zu schaffen.
Der Fokus ihrer Arbeit liegt auf den fünf Themenfeldern Energie, Infrastruktur, Umwelt, Material und Analytical Sciences. Wichtige Themen betreffen dabei sowohl die Energiewende (Wasserstoff, elektrische Energiespeicher, Windenergie) als auch Bereiche der Technologiesouveränität wie die additive Fertigung, zuverlässige Materialdaten, Zustandsüberwachung und Kreislaufwirtschaft.
Die Digitalisierung und den digitalen Wandel unterstützt die BAM in Bezug auf technologieübergreifende Rahmenbedingungen besonders in der Initiative Qualitätsinfrastruktur-Digital (QI-Digital), in der gemeinsam mit weiteren zentralen Akteuren der deutschen QI Lösungen für die Qualitätssicherung in einer digitalisierten Welt entwickelt werden.
Grundvoraussetzung für sichere Technologien und Innovationen ist eine leistungsfähige Forschung und Entwicklung ebenso wie Wissens- und Technologietransfer zur Umsetzung von Forschungsergebnissen in marktfähige Produkte und Dienstleistungen. Dafür bildet die Arbeit der BAM eine wichtige Basis.
Ihre Forschung ist mit der Wahrnehmung öffentlicher Aufgaben verbunden. Das Forschungsprogramm zeigt Perspektiven im Bereich ihres Aufgabenfeldes sowie ihrer damit verbundenen Forschungsaktivitäten transparent und politisch nutzbar auf und dient darüber hinaus der Koordinierung der Ressortforschung.
Das Forschungsprogramm der BAM wird alle zwei Jahre aktualisiert. Es gibt einen Überblick über die aktuellen und zukünftigen Forschungsthemen und die hierfür erforderlichen Rahmenbedingungen.
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572758
SP - 1
EP - 40
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-57275
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hülagü, Deniz
A1 - Tobias, Charlie
A1 - Gojani, Ardian B.
A1 - Rurack, Knut
A1 - Hodoroaba, Vasile-Dan
T1 - From 2D and Single Particle to 3D and Batch Analysis as a Routine Quality Check Procedure for the Morphological Characterization of Core-Shell Microparticles
N2 - CS particles show unique properties by merging individual characteristics of the core and the shell materials. An alteration particularly in their surface roughness affects the final performance of the particles in the targeted application. Quantitative evaluation of the roughness of CS microparticles is, however, a challenging task employing microscopic techniques being scarce and showing large differences in terms of methodology and results.
In our previous work, we have reported a systematic study with a reliable analysis tool, which evaluates profile roughness quantitatively, for individual core-shell microparticles using electron microscopy (EM) images of both types, Scanning Electron Microscopy (SEM) and transmission mode SEM (or TSEM). The SEM images contain two-dimensional (2D) information, therefore, provide profile roughness data only from the projection in the horizontal plane (in other words, from the “belly”) of a spherical particle. The present study offers a practical procedure to give access to more information by tilting the sample holder and hence allowing images of a single particle to be recorded at different orientations under the same view angle. From the analysis of these images, extended information on surface roughness of the particle can be extracted. Thus, instead of obtaining 2D information from a single SEM image, three-dimensional (3D) information is obtained from 2D projections recorded at different particle orientations.
T2 - Microscopy and Microanalysis 2022
CY - Oregon, Portland, USA
DA - 31.07.2022
KW - Core-shell particles
KW - Image processing
KW - Roughness
KW - Scanning electron microscopy
KW - Tilting
PY - 2022
DO - https://doi.org/10.1017/S1431927622002094
SN - 1431-9276
VL - 28
IS - S1
SP - 332
EP - 334
PB - Cambridge University Press
AN - OPUS4-55373
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Functional molecular chromophores and nanomaterials reporters, optical probes, and sensors
N2 - •Overview of expertise of division Biophotonics
•Functional molecular and nanoscale luminescent reporters, probes, and
sensors including design principles available from division Biophotonics
•Examples for pH and O2 responsive molecular probes and particle sensors
•Surface group quantification Analytical methods and cleavable probes
•Concepts & standards for the validation and traceability of optical measurements
T2 - FU-Seminar
CY - Berlin, Germany
DA - 09.12.2022
KW - Particle sensors
KW - Surface group quantification
KW - Nanoscale luminescent reporters
KW - Cleavable probes
PY - 2022
AN - OPUS4-56526
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Singh, Chandan
T1 - Functionalized Titanium Carbide Nanosheets based Biosensor for Detection of the SARS-CoV-2 Nucleocapsid Protein
N2 - MXenes are a new family of two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides discovered in 2011. Among many reported family members, titanium carbide is the most widely studied and explored due to the optimized synthesis conditions and promising characteristics like good mechanical strength, solution processability, and excellent conductivity. Here, we report the development of an electrochemical biosensor involving the amine-functionalized Few-Layered-Titanium Carbide Nanosheets and monoclonal antibodies against the SARS-CoV-2 nucleocapsid protein (anti-SARS-CoV-2 mAb) to design a point-of-care device for detection of the SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 NP) antigen.
T2 - SALSA's Make and Measure 2022
CY - Berlin, Germany
DA - 15.09.2022
KW - MXenes
KW - Titanium Carbide Nanosheets
KW - Biosensors
KW - Electrochemistry
PY - 2022
N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S.
AN - OPUS4-55856
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hülagü, Deniz
A1 - Tobias, Charlie
A1 - Climent Terol, Estela
A1 - Gojani, Ardian
A1 - Rurack, Knut
A1 - Hodoroaba, Vasile-Dan
T1 - Generalized Analysis Approach of the Profile Roughness by Electron Microscopy with the Example of Hierarchically Grown Polystyrene–Iron Oxide–Silica Core–Shell–Shell Particles
N2 - The roughness as a property of core–shell (CS) microparticles plays a key role in their functionality. Quantitative evaluation of the roughness of CS microparticles is, however, a challenging task with approaches using electron microscopy images being scarce and showing pronounced differences in terms of methodology and results. This work presents a generalized method for the reliable roughness determination of nonplanar specimens such as CS particles from electron microscopic images, the method being robust and reproducible with a high accuracy. It involves a self-written software package (Python) that analyzes the recorded images, extracts corresponding data, and calculates the roughness based on the deviation of the identified contour. Images of single particles are taken by a dual mode scanning electron microscopy (SEM) setup which permits imaging of the same field-of-view of the sample with high resolution and surface sensitive in SE InLens mode as well as in transmission mode (TSEM). Herein, a new type of polystyrene core–iron oxide shell–silica shell particles is developed to serve as a set of lower micrometer-sized study objects with different surface roughness; the analysis of their images by the semiautomatic workflow is demonstrating that the particles’ profile roughness can be quantitatively obtained.
KW - Core–shell particles
KW - Image analysis
KW - Nanoparticles
KW - Roughness
KW - SEM
KW - transmission mode
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542576
DO - https://doi.org/10.1002/adem.202101344
SP - 1
EP - 9
PB - Wiley-VCH
AN - OPUS4-54257
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Erdmann, Eileen
A1 - Nitsche, Sarah
A1 - Gorbushina, Anna
A1 - Schumacher, Julia
T1 - Genetic Engineering of the Rock Inhabitant Knufia petricola Provides Insight Into the Biology of Extremotolerant Black Fungi
N2 - Black microcolonial fungi (Ascomycetes from Arthonio-, Dothideo-, and Eurotiomycetes) are stress-tolerant and persistent dwellers of natural and anthropogenic extreme habitats. They exhibit slow yeast-like or meristematic growth, do not form specialized reproduction structures and accumulate the black pigment 1,8-dihydroxynaphthalene (DHN) melanin in the multilayered cell walls. To understand how black fungi live, survive, colonize mineral substrates, and interact with phototrophs genetic methods are needed to test these functions and interactions. We chose the rock inhabitant Knufia petricola of the Chaetothyriales as a model for developing methods for genetic manipulation. Here, we report on the expansion of the genetic toolkit by more efficient multiplex CRISPR/Cas9 using a plasmid-based system for expression of Cas9 and multiple sgRNAs and the implementation of the three resistance selection markers genR (geneticin/nptII), baR (glufosinate/bar), and suR (chlorimuron ethyl/sur). The targeted integration of expression constructs by replacement of essential genes for pigment synthesis allows for an additional color screening of the transformants. The black-pink screening due to the elimination of pks1 (melanin) was applied for promoter studies using GFP fluorescence as reporter. The black-white screening due to the concurrent elimination of pks1 and phs1 (carotenoids) allows to identify transformants that contain the two expression constructs for co-localization or bimolecular fluorescence complementation (BiFC) studies. The co-localization and interaction of the two K. petricola White Collar orthologs were demonstrated. Two intergenic regions (igr1, igr2) were identified in which expression constructs can be inserted without causing obvious phenotypes. Plasmids of the pNXR-XXX series and new compatible entry plasmids were used for fast and easy generation of expression constructs and are suitable for a broad implementation in other fungi. This variety of genetic tools is opening a completely new perspective for mechanistic and very detailed study of expression, functioning and regulation of the genes/proteins encoded by the genomes of black fungi.
KW - Microcolonial fungi
KW - DHN melanin
KW - Cloning vectors
KW - Genetics
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546192
DO - https://doi.org/10.3389/ffunb.2022.862429
SN - 2673-6128
VL - 3
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-54619
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schneider, Beate
A1 - Pfeiffer, F.
A1 - Dyall-Smith, M.
A1 - Kunte, Hans-Jörg
T1 - Genome Sequence of Cupriavidus campinensis Strain G5, a Member of a Bacterial Consortium Capable of Polyethylene Degradation
N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G5 was determined by PacBio sequencing. Using the TYGS for taxonomic classification, strain G5 was assigned to the species Cupriavidus campinensis.
KW - Polyethylene
KW - Cupriavidus campinensis
KW - Plastic degradation
KW - Genome sequence
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557897
DO - https://doi.org/10.1128/mra.00553-22
SP - 1
EP - 2
PB - ASM
AN - OPUS4-55789
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schneider, Beate
A1 - Pfeiffer, F.
A1 - Dyall-Smith, M.
A1 - Kunte, Hans-Jörg
T1 - Genome Sequence of Micromonospora aurantiaca Strain G9, a Member of a Bacterial Consortium Capable of Polyethylene Degradation
N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G9 was determined by PacBio sequencing. Using the TYGS server for taxonomic classification, strain G9 was assigned to the species Micromonospora aurantiaca.
KW - Polyethylene
KW - Micromonospora aurantiaca
KW - Degradation
KW - iChip
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547181
DO - https://doi.org/10.1128/mra.01148-21
SN - 2576-098X
VL - 11
IS - 5
SP - 1
EP - 2
PB - American Society for Microbiology
CY - Washington, DC
AN - OPUS4-54718
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schneider, Beate
A1 - Pfeiffer, F.
A1 - Dyall-Smith, M.
A1 - Kunte, Hans-Jörg
T1 - Genome Sequence of Pseudomonas veronii Strain G2, a Member of a Bacterial Consortium Capable of Polyethylene Degradation
N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G2 was determined by PacBio sequencing. Using the TYGS server for taxonomic classification, strain G2 was assigned to the species Pseudomonas veronii.
KW - Polyethylene
KW - Next generation sequencing
KW - Pseudomonas veronii
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548973
DO - https://doi.org/10.1128/mra.00365-22
SP - 1
EP - 2
PB - ASM
AN - OPUS4-54897
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Darvishi Kamachali, Reza
T1 - Grain Boundary Segregation Design using CALPHAD-integrated Phase-Field Modelling
N2 - A main source of current challenges in materials science and engineering is the ever-increasing complexity in materials chemistry and processing resulting in complex microstructures, making the assessment of process-microstructure-property-performance relations difficult, even unmanageable. Here the computational materials science is facing the same situation. In this talk, I share a viewpoint that the complexities in chemistry, processing and microstructures can be circumscribed by integrating existing knowledges of bulk thermodynamics and kinetics to the unknown thermodynamics and kinetics of microstructure elements. To this end, I discuss several successful examples on grain boundary segregation engineering how this scientific advance can be conducted. A roadmap is proposed, beginning to form on generalizing the concept of phase diagrams.
T2 - ICAMS Advance Discussions: Advanced models for microstructure evolution – process-microstructure-property relationships
CY - Bochum, Germany
DA - 26.10.2022
KW - Microstructure Design
KW - CALPHAD
KW - Phase-Field Simulations
KW - Machine Learning
KW - Phase Diagrams
PY - 2022
AN - OPUS4-56348
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fahmy, A.
A1 - Anis, B.
A1 - Szymoniak, Paulina
A1 - Altmann, Korinna
A1 - Schönhals, Andreas
T1 - Graphene Oxide/Polyvinyl Alcohol–Formaldehyde Composite Loaded by Pb Ions: Structure and Electrochemical Performance
N2 - An immobilization of graphene oxide (GO) into a matrix of polyvinyl formaldehyde (PVF) foam as an eco-friendly, low cost, superior, and easily recovered sorbent of Pb ions from an aqueous solution is described. The relationships between the structure and electrochemical properties of PVF/GO composite with implanted Pb ions are discussed for the first time. The number of alcohol groups decreased by 41% and 63% for PVF/GO and the PVF/GO/Pb composite, respectively, compared to pure PVF. This means that chemical bonds are formed between the Pb ions and the PVF/GO composite based on the OH groups. This bond formation causes an increase in the Tg values attributed to the formation of a strong surface complexation between adjacent layers of PVF/GO composite. The conductivity increases by about 2.8 orders of magnitude compared to the values of the PVF/GO/Pb composite compared to the PVF. This means the presence of Pb ions is the main factor for enhancing the conductivity where the conduction mechanism is changed from ionic for PVF to electronic conduction for PVF/GO and PVF/GO/Pb.
KW - Graphene oxide
KW - Polyvinyl formaldehyde
KW - Lead ions
KW - Conductivity
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549588
DO - https://doi.org/10.3390/polym14112303
SN - 2073-4360
VL - 14
IS - 11
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-54958
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Jungnickel, R.
A1 - Mirabella, Francesca
A1 - Stockmann, Jörg Manfred
A1 - Radnik, Jörg
A1 - Balasubramanian, K.
T1 - Graphene‑on‑gold surface plasmon resonance sensors resilient to high‑temperature annealing
N2 - Gold films coated with a graphene sheet are being widely used as sensors for the detection of label-free binding interactions using surface plasmon resonance (SPR). During the preparation of such sensors, it is often essential to subject the sensor chips to a high-temperature treatment in order to ensure a clean graphene surface. However, sensor chips used currently, which often use chromium as an adhesion promoter, cannot be subjected to temperatures above 250 °C, because under such conditions, chromium is found to reorganize and diffuse to the surface, where it is easily oxidized, impairing the quality of SPR spectra. Here we present an optimized preparation strategy involving a three-cycle tempering coupled with chromium (oxide) etching, which allows the graphene-coated SPR chips to be annealed up to 500 °C with little deterioration of the surface morphology. In addition, the treatment delivers a surface that shows a clear enhancement in spectral response together with a good refractive index sensitivity. We demonstrate the applicability of our sensors by studying the kinetics of avidin–biotin binding at different pH repeatedly on the same chip. The possibility to anneal can be exploited to recover the original surface after sensing trials, which allowed us to reuse the sensor for at least six cycles of biomolecule adsorption.
KW - Surface plasmon resonance
KW - Graphene
KW - Sensing
KW - Surface regeneration
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564585
DO - https://doi.org/10.1007/s00216-022-04450-4
SN - 1618-2642
SP - 1
EP - 7
PB - Springer
AN - OPUS4-56458
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Altmann, Korinna
T1 - Harmonisation efforts of the CUSP projects
N2 - The talk is about harmonisation approaches within CUSP. First the five H2020 projects for research on risk assessment regarding microplastics topic were presented. Secondly, harmonisation process were discussed.
T2 - VAMAS SC 47 Meeting
CY - Turin, Italy
DA - 19.10.2022
KW - Microplastics
KW - Harmonisation
KW - Nanoplastics
KW - H2020
KW - Risk assessment
PY - 2022
AN - OPUS4-56077
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zou, Q.
A1 - Marcelot, C.
A1 - Ratel-Ramond, N.
A1 - Yi, X.
A1 - Roblin, P.
A1 - Frenzel, Florian
A1 - Resch-Genger, Ute
A1 - Eftekhari, A.
A1 - Bouchet, A.
A1 - Coudret, C.
A1 - Verelst, M.
A1 - Chen, X.
A1 - Mauricot, R.
A1 - Roux, C.
T1 - Heterogeneous Oxysulfide@Fluoride Core/ Shell Nanocrystals for Upconversion-Based Nanothermometry
N2 - Lanthanide (Ln3+)-doped upconversion nanoparticles (UCNPs) often suffer from weak luminescence, especially when their sizes are ultrasmall (less than 10 nm). Enhancing the upconversion luminescence (UCL) efficiency of ultrasmall UCNPs has remained a challenge that must be undertaken if any practical applications are to be envisaged. Herein, we present a Ln3+-doped oxysulfide@fluoride core/shell heterostructure which shows efficient UCL properties under 980nm excitation and good stability in solution. Through epitaxial heterogeneous growth, a ∼4 nm optically inert β-NaYF4 shell was coated onto ∼5 nm ultrasmall Gd2O2S:20%Yb,1%Tm. These Gd2O2S:20%Yb,1%Tm@NaYF4 core/shell UCNPs exhibit a more than 800-fold increase in UCL intensity compared to the unprotected core, a 180-fold increase in luminescence decay time of the 3H4 → 3H6 Tm3+ transition from 5 to 900 μs, and an upconversion quantum yield (UCQY) of 0.76% at an excitation power density of 155 W/cm2. Likewise, Gd2O2S:20%Yb,2%Er@NaYF4 core/shell UCNPs show a nearly 5000-fold
increase of their UCL intensity compared to the Gd2O2S:20%Yb,2%Er core and a maximum UCQY of 0.61%. In the Yb/Er core−shell UCNP system, the observed variation of luminescence intensity ratio seems to originate from a change in lattice strain as the temperature is elevated. For nanothermometry applications, the thermal sensitivities based on thermally coupled levels are estimated for both Yb/Tm and Yb/Er doped Gd2O2S@NaYF4 core/shell UCNPs.
KW - Upconversion nanoparticle
KW - Nanosensor
KW - Lanthanide
KW - Surface coating
KW - Quantum yield
KW - Photophysic
PY - 2022
DO - https://doi.org/10.1021/acsnano.2c02423
SN - 1936-0851
SP - 1
EP - 11
PB - ACS Publications
AN - OPUS4-55440
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Henning, L. M.
A1 - Müller, J. T.
A1 - Smales, Glen Jacob
A1 - Pauw, Brian Richard
A1 - Schmidt, J.
A1 - Bekheet, M. F.
A1 - Gurlo, A.
A1 - Simon, U.
T1 - Hierarchically porous and mechanically stable monoliths from ordered mesoporous silica and their water filtration potential
N2 - Mechanically stable structures with interconnected hierarchical porosity combine the benefits of both small
and large pores, such as high surface area, pore volume, and good mass transport capabilities. Hence, lightweight micro-/meso-/macroporous monoliths are prepared from ordered mesoporous silica COK-12 by means of spark plasma sintering (SPS, S-sintering) and compared to conventionally (C-) sintered monoliths. A multi-scale model is developed to fit the small angle X-ray scattering data and obtain information on the hexagonal lattice parameters, pore sizes from the macro to the micro range, as well as the dimensions of the silica population. For both sintering techniques, the overall mesoporosity, hexagonal pore ordering, and amorphous character are preserved. The monoliths' porosity (77–49%), mesopore size (6.2–5.2 nm), pore volume (0.50–0.22 g cm-3
), and specific surface area (451–180 m2 g-1) decrease with increasing processing temperature and pressure. While the difference in porosity is enhanced, the
structural parameters between the C-and S-sintered monoliths are largely converging at 900 C, except for the mesopore size and lattice parameter, whose dimensions are more extensively preserved in the
S-sintered monoliths, however, coming along with larger deviations from the theoretical lattice. Their higher mechanical properties (biaxial strength up to 49 MPa, 724 MPa HV 9.807 N) at comparable porosities and ability to withstand ultrasonic treatment and dead-end filtration up to 7 bar allow S-sintered monoliths to reach a high permeance (2634 L m-2 h-1 bar-1), permeability (1.25 x 10^-14 m2), and ability to reduce the chemical oxygen demand by 90% during filtration of a surfactant-stabilized oil in water emulsion, while indicating reasonable resistance towards fouling.
KW - SAXS
KW - Hierarchically porous
KW - Silica
KW - Water filtration
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555928
DO - https://doi.org/10.1039/D2NA00368F
SN - 2516-0230
SP - 1
EP - 17
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-55592
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Falqueto, J. B.
A1 - Clark, A. H.
A1 - Štefančič, A.
A1 - Smales, Glen Jacob
A1 - Vaz, C. A. F.
A1 - Schuler, A. J.
A1 - Bocchi, N.
A1 - Kazzi, M. E.
T1 - High performance doped Li-rich Li1+xMn2–xO4 cathodes nanoparticles synthesized by facile, fast, and efficient microwave-assisted hydrothermal route
N2 - Li-rich nanoparticles of Li1+xMn2–xO4 doped with Al, Co, or Ni are successfully synthesized using a facile, fast, and efficient microwave-assisted hydrothermal route. Synchrotron X-ray diffraction confirms the formation of the crystalline cubic spinel phase type. X-ray absorption spectroscopy analysis at the Co and Ni K- and L-edges verifies that the dopants are within the Li1+xMn2–xO4 spinel structure and are inactive during cycling in the bulk and at the surface. Moreover, we demonstrate that nanocrystallinity and cationic doping play an important role in improving the electrochemical performance with respect to LiMn2O4 microparticles. They significantly reduce the charge-transfer resistance, lower the first cycle irreversible capacity loss to 6%, and achieve a capacity retention between 85 and 90% after 380 cycles, with excellent Coulombic efficiency close to 99% without compromising the specific charge at a 5C cycling rate. Furthermore, the Mn K- and L-edges attest that after long cycling, the Mn oxidation state in the bulk differs from that at the surface caused by the Mn disproportion reaction; however, the cationic doping helps mitigate the Mn dissolution with respect to the undoped Li1+xMn2–xO4 nanoparticles, as indicated by inductively coupled plasma atomic emission spectrometry.
KW - XAS
KW - SAXS
KW - Li-ion battery
KW - Cathode material
KW - Spinel
KW - The MOUSE
PY - 2022
DO - https://doi.org/10.1021/acsaem.2c00902
SN - 2574-0962
VL - 5
IS - 7
SP - 8357
EP - 8370
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-55359
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Topolniak, Ievgeniia
A1 - Elert, Anna Maria
A1 - Knigge, Xenia
A1 - Ciftci, G. C.
A1 - Radnik, Jörg
A1 - Sturm, Heinz
T1 - High precision micropatterning of polydopamine by Multiphoton Lithography
N2 - Mussel-inspired polydopamine (PDA) initiated a multifunctional modification route that leads to the generation of novel advanced materials and their applications. However, existing PDA deposition techniques still exhibit poor spatial control, have a very limited capability of micropatterning and do not allow to locally tune PDA topography. Herein, we demonstrate PDA deposition based on Multiphoton Lithography (MPL) that enables full spatial and temporal control with nearly total freedom of patterning design. Using MPL, we achieve 2D microstructures of complex design with pattern precision of 0.8 μm without the need of a photomask or stamp. Moreover, this approach permits adjusting the morphology and thickness of the fabricated microstructure within one deposition step, resulting in a unique tunability of materials properties. The chemical composition of PDA is confirmed and its ability for protein enzyme immobilization is demonstrated. This work presents a new methodology for high precision and complete control of PDA deposition, enabling PDA incorporation in applications where fine and precise local surface functionalization is required. Possible applications include multicomponent functional elements and devices in microfluidics or lab-on-a-chip systems.
KW - Multiphoton lithography
KW - Polydopamine
KW - Micropatterning
PY - 2022
DO - https://doi.org/10.1002/adma.202109509
VL - 34
IS - 18
SP - e2109509
PB - Wiley online library
AN - OPUS4-54535
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ziesche, R.F.
A1 - Hack, J.
A1 - Rasha, L.
A1 - Maier, M.
A1 - Tan, C.
A1 - Heenan, T.M.M.
A1 - Markötter, Henning
A1 - Kardjilov, N.
A1 - Manke, I.
A1 - Kockelmann, W.
A1 - Brett, D.J.L.
A1 - Shearing, P.R.
T1 - High-speed 4D neutron computed tomography for quantifying water dynamics in polymer electrolyte fuel cells
N2 - In recent years, low-temperature polymer electrolyte fuel cells have become an increasingly important pillar in a zero-carbon strategy for curbing climate change, with their potential to power multiscale stationary and mobile applications. The performance improvement is a particular focus of research and engineering roadmaps, with water management being one of the major areas of interest for development. Appropriate characterisation tools for mapping the evolution, motion and removal of water are of high importance to tackle shortcomings.
This article demonstrates the development of a 4D high-speed neutron imaging technique, which enables a quantitative analysis of the local water evolution. 4D visualisation allows the time-resolved studies of droplet formation in the flow fields and water quantification in various cell parts. Performance parameters for water management are identified that offer a method of cell classification, which will, in turn, support computer modelling and the engineering of next-generation flow field designs.
KW - Neutron imaging
KW - Tomography
KW - Polymer electrolyte membrane fuel cell
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545978
DO - https://doi.org/10.1038/s41467-022-29313-5
VL - 13
IS - 1
SP - 1616
PB - Nature Publishing Group UK
CY - London
AN - OPUS4-54597
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Porta-Velilla, L.
A1 - Turan, N.
A1 - Cubero, Á.
A1 - Shao, W.
A1 - Li, H.
A1 - de la Fuente, G.F.
A1 - Martínez, E.
A1 - Larrea, Á.
A1 - Castro, M.
A1 - Koralay, H.
A1 - Çavdar, Ş.
A1 - Bonse, Jörn
A1 - Angurel, L.A.
T1 - Highly Regular Hexagonally-Arranged Nanostructures on Ni-W Alloy Tapes upon Irradiation with Ultrashort UV Laser Pulses
N2 - Nickel tungsten alloy tapes (Ni—5 at% W, 10 mm wide, 80 µm thick, biaxially textured) used in second-generation high temperature superconductor (2G-HTS) technology were laser-processed in air with ultraviolet ps-laser pulses (355 nm wavelength, 300 ps pulse duration, 250–800 kHz pulse repetition frequency). By employing optimized surface scan-processing strategies, various laser-generated periodic surface structures were generated on the tapes. Particularly, distinct surface microstructures and nanostructures were formed. These included sub-wavelength-sized highly-regular hexagonally-arranged nano-protrusions, wavelength-sized line-grating-like laser-induced periodic surface structures (LIPSS, ripples), and larger irregular pyramidal microstructures. The induced surface morphology was characterized in depth by electron-based techniques, including scanning electron microscopy (SEM), electron back scatter diffraction (EBSD), cross-sectional transmission electron microscopy (STEM/TEM) and energy dispersive X-ray spectrometry (EDS). The in-depth EBSD crystallographic analyses indicated a significant impact of the material initial grain orientation on the type of surface nanostructure and microstructure formed upon laser irradiation. Special emphasis was laid on high-resolution material analysis of the hexagonally-arranged nano-protrusions. Their formation mechanism is discussed on the basis of the interplay between electromagnetic scattering effects followed by hydrodynamic matter re-organization after the laser exposure. The temperature stability of the hexagonally-arranged nano-protrusion was explored in post-irradiation thermal annealing experiments, in order to qualify their suitability in 2G-HTS fabrication technology with initial steps deposition temperatures in the range of 773–873 K.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Ultrashort laser processing
KW - Hexagonally-arranged nano-protrusions
KW - Second-generation high temperature superconductor technology
KW - Electron microscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552551
DO - https://doi.org/10.3390/nano12142380
SN - 2079-4991
VL - 12
IS - 14
SP - 1
EP - 23
PB - MDPI
CY - Basel, Switzerland
AN - OPUS4-55255
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Rhode, Michael
A1 - Nietzke, Jonathan
A1 - Richter, Tim
T1 - Hydrogen diffusion and desorption characteristics of a CoCrFeMnNi high entropy and a CoCrNi medium entropy alloy
N2 - High-entropy alloys (HEAs) are innovative high-performance materials that have attracted more and more research attention. HEAs are characterized by a solid solution of typically five equiatomic metallic elements. In addition, medium-entropy alloys (MEA, with three elements) are of interest and become more and more important. Depending on the alloy concept, HEAs and MEAs show exceptional mechanical properties, especially high-strength and ductility combinations at both cryogenic and elevated temperatures combined with excellent corrosion resistance. Future structural HEA/MEA components can be exposed to potential applications with hydrogen containing environments like high-temperature water in pressurized nuclear reactors or aerospace structures. Other potential applications could be in materials for vessel walls in the field of cryogenic and high-pressure hydrogen storage. So far, the susceptibility of HEAs/MEAs to hydrogen assisted cracking (if any) and the hydrogen diffusion is not investigated in detail yet and can limit or extend possible applications of HEA/MEA as structural materials. In our work, we focused on the hydrogen absorption, diffusion, and distribution in a HEA (CoCrFeMnNi the original Cantor-alloy) and a MEA (CoCrNi). Cathodic hydrogen charging was carried out for the hydrogen ingress, and thermal desorption analysis (TDA) revealed complex hydrogen trapping in both alloy types up to 300 °C. The absorbed total hydrogen concentrations were > 100 ppm for the HEA and > 40 ppm for MEA. In addition, the assessment of the peak deconvolution is not trivial and must consider both experimental and microstructure influences.
T2 - 4th International Conference on Metals and Hydrogen - Steely & Hydrogen 2022
CY - Ghent, Belgium
DA - 11.10.2022
KW - Hydrogen
KW - High-entropy alloy
KW - Multiple principal element alloy
KW - Thermal desorption analysis
KW - Diffusion
PY - 2022
SP - 1
EP - 11
CY - Ghent, Belgium
AN - OPUS4-56076
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhao, H.
A1 - Chakraborty, Poulami
A1 - Ponge, D.
A1 - Hickel, Tilmann
A1 - Sun, B.
A1 - Wu, C.-H.
A1 - Gault, B.
A1 - Raabe, D.
T1 - Hydrogen trapping and embrittlement in high-strength Al alloys
N2 - Ever more stringent regulations on greenhouse gas emissions from transportation motivate efforts to revisit materials used for vehicles. High-strength aluminium alloys often used in aircrafts could help reduce the weight of automobiles, but are susceptible to environmental degradation. Hydrogen ‘embrittlement’ is often indicated as the main culprit; however, the exact mechanisms underpinning failure are not precisely known: atomic-scale analysis of H inside an alloy remains a challenge, and this prevents deploying alloy design strategies to enhance the durability of the materials. Here we performed near-atomic-scale analysis of H trapped in second-phase particles and at grain boundaries in a high-strength 7xxx Al alloy. We used these observations to guide atomistic ab initio calculations, which show that the co-segregation of alloying elements and H favours grain boundary decohesion, and the strong partitioning of H into the second-phase particles removes solute H from the matrix, hence preventing H embrittlement. Our insights further advance the mechanistic understanding of H-assisted embrittlement in Al alloys, emphasizing the role of H traps in minimizing cracking and guiding new alloy design.
KW - Atomistic models
KW - Hydrogen
KW - Metals and alloys
KW - Mechanical properties
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543631
DO - https://doi.org/10.1038/s41586-021-04343-z
SN - 1476-4687
VL - 602
IS - 7897
SP - 437
EP - 441
PB - Nature Publ. Group
CY - London
AN - OPUS4-54363
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Erning, Johann Wilhelm
ED - Leyens, C.
T1 - Hygienische Eigenschaften von additiv gefertigtem 1.4404 in Trinkwasser
N2 - Elektrochemische Messungen zur hygienischen Bewertung additiv gefertigter Bauteile werden diskutiert. Die Bewertung und Details des Werkstoffs werden beschrieben, Anwendungsbeispiele werden gezeigt.
T2 - 3. Fachtagung Werkstoffe und Additive Fertigung
CY - Dresden, Germany
DA - 11.05.2022
KW - Korrosion
KW - Trinkwasser
KW - Hygienische Bewertung
KW - Additive Fertigung
PY - 2022
SN - 978-3-88355-423-2
SP - 126
EP - 127
PB - Deutsche Gesellschaft für Materialkunde (DGM)
CY - Sankt Augustin
AN - OPUS4-54933
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Boyraz, B.
A1 - Saatz, Jessica
A1 - Pompös, I.-M.
A1 - Gad, Michel
A1 - Dernedde, J.
A1 - Maier, A.-M. B.
A1 - Moscovitz, O.
A1 - Seeberger, P. H.
A1 - Traub, Heike
A1 - Tauber, R.
T1 - Imaging Keratan Sulfate in Ocular Tissue Sections by Immunofluorescence Microscopy and LA-ICP-MS
N2 - Carbohydrate-specific antibodies can serve as valuable tools to monitor alterations in the extracellular matrix resulting from pathologies. Here, the keratan sulfate-specific monoclonal antibody MZ15 was characterized in more detail by immunofluorescence microscopy as well as laser ablation ICP-MS using tissue cryosections and paraffin-embedded samples. Pretreatment with keratanase II prevented staining of samples and therefore demonstrated efficient enzymatic keratan sulfate degradation. Random fluorescent labeling and site-directed introduction of a metal cage into MZ15 were successful and allowed for a highly sensitive detection of the keratan sulfate landscape in the corneal stroma from rats and human tissue.
KW - Laser ablation
KW - Imaging
KW - Glycosaminoglycan
KW - ICP-MS
KW - Immunohistochemistry
KW - Immunofluorescence
KW - Tissue
PY - 2022
DO - https://doi.org/10.1021/acsabm.1c01240
VL - 5
IS - 2
SP - 853
EP - 861
PB - American Chemical Society
CY - Washington
AN - OPUS4-54341
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Climent Terol, Estela
A1 - Weller, Michael G.
A1 - Martínez-Mánez, R.
A1 - Rurack, Knut
T1 - Immunochemical design of antibody-gated indicator delivery (gAID) systems based on mesoporous silica nanoparticles
N2 - In this work, the optimization of the immunochemical response of antibody-gated indicator delivery (gAID) systems prepared with mesoporous silica nanoparticles has been studied along various lines of system tailoring, targeting the peroxide-type explosive TATP as an exemplary analyte. The mechanism of detection of these gAID systems relies on a displacement of an antibody “cap” bound to hapten derivatives anchored to the surface of a porous hybrid material, allowing the indicator cargo stored in the mesopores to escape and massively amplify the analyte-related signal. Since our aim was to obtain gAID systems with the best possible response in terms of sensitivity, selectivity, and assay time, sera obtained from different immunization boosts were screened, the influence of auxiliary reagents was assessed, structural hapten modification (hapten heterology) was investigated, and various indicator dyes and host materials were tested. Considering that highly selective and sensitive immunological responses are best obtained with high-affinity antibodies which, however, could possess rather slow dissociation constants, leading to slow responses, the main challenge was to optimize the immunochemical recognition system for a rapid response while maintaining a high sensitivity and selectivity. The best performance was observed by grafting a slightly mismatching (heterologous) hapten to the surface of the nanoparticles in combination with high-affinity antibodies as “caps”, yielding for the first time gAID nanomaterials for which the response time could be improved from hours to <5 min. The materials showed favorable detection limits in the lower ppb range and discriminated TATP well against H2O2 and other explosives. Further optimization led to straightforward integration of the materials into a lateral flow assay without further treatment or conditioning of the test strips while still guaranteeing remarkably fast overall assay times.
KW - Antibody-gated indicator delivery systems
KW - Signal amplification
KW - Immunochemical response optimization
KW - Test strip analysis
KW - TATP
KW - Explosives detection
KW - Heterologous hapten
PY - 2022
DO - https://doi.org/10.1021/acsanm.1c03417
SN - 2574-0970
VL - 5
IS - 1
SP - 626
EP - 641
PB - American Chemical Society
CY - Washington, DC
AN - OPUS4-54176
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Usmani, S.
A1 - Voss, L.
A1 - Stephan, Ina
A1 - Hübert, Thomas
A1 - Kemnitz, E.
T1 - Improved Durability of Wood Treated with Nano Metal Fluorides against Brown-Rot and White-Rot Fungi
N2 - Low-water soluble metal fluorides such as magnesium fluoride (MgF2) and calcium Fluoride (CaF2) were evaluated for decay protection of wood. Initially, the biocidal efficacy of nano metal fluorides (NMFs) against wood destroying fungi was assessed with an in-vitro agar test. The results from the test showed that agar medium containing MgF2 and CaF2 was more efficient in preventing fungal decay than stand-alone MgF2 or CaF2. These metal fluorides, in their nanoscopic form synthesized using fluorolytic sol-gel synthesis, were introduced into the sapwood of Scots pine and beech wood and then subjected to accelerated ageing by leaching (EN 84). MAS 19F NMR and X-ray micro CT images showed that metal fluorides were present in treated wood, unleached and leached. Decay resistance of Scots pine and beech wood treated with NMFs was tested against Wood destroying fungi Rhodonia placenta and Trametes versicolor in accordance with EN 113. Results revealed that mass losses were reduced to below 3% in wood treated with the combination of MgF2 and CaF2.
It is concluded that NMFs provide full protection to wood even after it has been leached and can be used as wood preservatives in outdoor environments.
KW - Nanoparticles
KW - Fluoride
KW - Wood protection
KW - Fluorolytic sol-gel synthesis
KW - Brown-rot fungi
KW - White-rot fungi
KW - Basidiomycetes
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543877
DO - https://doi.org/10.3390/app12031727
VL - 12
IS - 3
SP - 1
EP - 11
PB - MDPI
AN - OPUS4-54387
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chambers, M. S.
A1 - Hunter, R. D.
A1 - Hollamby, M. J.
A1 - Pauw, Brian Richard
A1 - Smith, A. J.
A1 - Snow, T.
A1 - Danks, A. E.
A1 - Schnepp, Z.
T1 - In Situ and Ex Situ X‑ray Diffraction and Small-Angle X‑ray Scattering Investigations of the Sol−Gel Synthesis of Fe3N and Fe3C
N2 - Iron nitride (Fe3N) and iron carbide (Fe3C) nanoparticles can be prepared via sol−gel synthesis. While sol−gel methods are simple, it can be difficult to control the crystalline composition, i.e., to achieve a Rietveld-pure product. In a previous in situ synchrotron study of the sol−gel synthesis of Fe3N/Fe3C, we showed that the reaction proceeds as follows:
Fe3O4 → FeOx → Fe3N → Fe3C. There was considerable overlap between the different phases, but we were unable to ascertain whether this was due to the experimental setup (side-on heating of a quartz capillary which could lead to thermal gradients) or whether individual particle reactions proceed at different rates. In this paper, we use in situ wide- and small-angle X-ray scattering (wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS)) to demonstrate that the overlapping phases are indeed due to variable reaction rates. While the initial oxide nanoparticles have a small range of diameters, the size range expands considerably and very rapidly during the oxide−nitride transition. This has implications for the isolation of Rietveld-pure Fe3N, and in an extensive laboratory study, we were indeed unable to isolate phasepure Fe3N. However, we made the surprising discovery that Rietveld-pure Fe3C nanoparticles can be produced at 500 °C with a sufficient furnace dwell time. This is considerably lower than the previous reports of the sol−gel synthesis of Fe3C nanoparticles.
KW - Small-angle X-ray Scattering
KW - SAXS
KW - Diffraction
KW - XRD
KW - Scattering
KW - Sol-gel
KW - Iron nitride
KW - Nanoparticles
KW - Iron carbide
KW - Catalyst
KW - In-situ
KW - Ex-situ
KW - Synthesis
KW - Synchrotron
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548226
DO - https://doi.org/10.1021/acs.inorgchem.1c03442
VL - 61
IS - 18
SP - 6742
EP - 6749
PB - ACS Publications
CY - Washington
AN - OPUS4-54822
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Almalla, A.
A1 - Özcan Sandikcioglu, Özlem
A1 - Witt, Julia
T1 - In Situ Atomic Force Microscopy Analysis of the Corrosion Processes at the Buried Interface of an Epoxy-like Model Organic Film and AA2024-T3 Aluminum Alloy
N2 - The application of characterization methods with high spatial resolution to the analysis of buried coating/metal interfaces requires the design and use of model systems. Herein, an epoxy-like thin film is used as a model coating resembling the epoxy-based coatings and adhesives widely used in technical applications. Spin coating is used for the deposition of a 30 nm-thin bilayer (BL) composed of poly-(ethylenimine) (PEI) and poly[(o-cresyl glycidyl ether)-co-formaldehyde] (CNER). Fourier-transform infrared spectroscopy (FTIR) results confirm that the exposure of coated AA2024-T3 (AA) samples to the corrosive electrolyte solution does not cause the degradation of the polymer layer. In situ atomic force microscopy (AFM) studies are performed to monitor local corrosion processes at the buried interface of the epoxy-like film and the AA2024-T3 aluminum alloy surface in an aqueous electrolyte solution. Hydrogen evolution due to the reduction of water as the cathodic corrosion reaction leads to local blister formation. Based on the results of the complementary energy-dispersive X-ray spectroscopy (EDX) analysis performed at the same region of interest, most of the hydrogen evolved originates at the vicinity of Mg-containing intermetallic particles.
KW - Scanning Kelvin probe force microscopy
KW - Aluminum alloys
KW - Buried interfaces
KW - In situ atomic force microscopy
KW - Local corrosion
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546932
DO - https://doi.org/10.1002/adem.202101342
SN - 1438-1656
SP - 1
EP - 9
PB - Wiley VHC-Verlag
AN - OPUS4-54693
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Shimada, Y.
A1 - Ikeda, Yuki
A1 - Yoshida, K.
A1 - Sato, M.
A1 - Chen, J.
A1 - Du, Y.
A1 - Inoue, K.
A1 - Maaß, Robert
A1 - Nagai, Y.
A1 - Konno, T.
T1 - In situ thermal annealing transmission electron microscopy of irradiation induced Fe nanoparticle precipitation in Fe–Si alloy
N2 - The typical experimental conditions inside a transmission electron microscope (TEM), such as ultra-high vacuum, high-energy electron irradiation, and surface effects of ultrathin TEM specimens, can be the origin of unexpected microstructural changes compared with that of bulk material during in situ thermal-annealing experiments. In this paper, we report on the microstructural changes of a Fe–15%Si alloy during in situ TEM annealing, where, in its bulk form, it exhibits an ordering transformation from D03 to B2 at 650 °C. Using a heating-pot type double tilt holder with a proportional–integral–differential control system, we observed the precipitation of α-Fe both at the sample surface and inside the sample. Surface precipitates formed via surface diffusion are markedly large, several tens of nm, whereas precipitates inside the specimen, which are surrounded by Fe-poor regions, reach a maximum size of 20 nm. This unexpected microstructural evolution could be attributed to vacancies on Si sites, which are induced due to high-energy electron irradiation before heating, as well as enhanced thermal diffusion of Fe atoms.
KW - In situ thermal-annealing experiment
KW - Microstructural changes of a Fe Si alloy
KW - Microstructural evolution
PY - 2022
DO - https://doi.org/10.1063/5.0070471
SN - 0021-8979
VL - 131
IS - 16
SP - 1
EP - 8
PB - AIP Publishing
AN - OPUS4-54728
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dietrich, P. M.
A1 - Kjærvik, Marit
A1 - Willneff, E. A.
A1 - Unger, Wolfgang
T1 - In-depth analysis of iodine in artificial biofilm model layers by variable excitation energy XPS and argon gas cluster ion sputtering XPS
N2 - Here, we present a study on agarose thin-film samples that represent a model system for the exopolysaccharide matrix of biofilms. Povidone-iodide (PVP-I) was selected as an antibacterial agent to evaluate our x-ray photoelectron spectroscopy (XPS)-based methodology to trace specific marker elements, here iodine, commonly found in organic matrices of antibiotics. The in-depth distribution of iodine was determined by XPS analyses with variable excitation energies and in combination with argon gas cluster ion beam sputter cycles. On mixed agarose/PVP-I nanometer-thin films, both methods were found to solve the analytical task and deliver independently comparable results. In the mixed agarose/PVP-I thin film, we found the outermost surface layer depleted in iodine, whereas the iodine is homogeneously distributed in the depth region between this outermost surface layer and the interface between the thin film and the substrate. Depletion of iodine from the uppermost surface in the thin-film samples is assumed to be caused by ultrahigh vacuum exposure resulting in a loss of molecular iodine (I2) as reported earlier for other iodine-doped polymers.
KW - Biofilm
KW - XPS
KW - Argon gas cluster ion sputtering
KW - Variable excitation
KW - Iodine
PY - 2022
DO - https://doi.org/10.1116/6.0001812
SN - 1934-8630
VL - 17
IS - 3
SP - 1
EP - 8
PB - AVS
AN - OPUS4-54973
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Roveda, Ilaria
A1 - Serrano-Munoz, Itziar
A1 - Mishurova, Tatiana
A1 - Madia, Mauro
A1 - Pirling, T.
A1 - Evans, Alexander
A1 - Klaus, M.
A1 - Haubrich, J.
A1 - Requena, G.
A1 - Bruno, Giovanni
T1 - Influence of a 265 °C heat treatment on the residual stress state of a PBF-LB/M AlSi10Mg alloy
N2 - Laser Powder Bed Fusion (PBF-LB/M) additive manufacturing (AM) induces
high magnitude residual stress (RS) in structures due to the extremely heterogeneous cooling and heating rates. As the RS can be deleterious to the fatigue resistance of engineering components, great efforts are focused on understanding their generation and evolution after post-process heat treatments. In this study, one of the few of its kind, the RS relaxation induced in an as-built PBF-LB/M AlSi10Mg material by a low-temperature heat treatment (265 °C for 1 h) is studied by means of X-ray and neutron diffraction. Since the specimens are manufactured using a baseplate heated up to 200 °C, low RS are found in the as-built condition. After heat treatment a redistribution of the RS is observed, while their magnitude remains constant. It is proposed that the redistribution is induced by a repartition of stresses between the a-aluminium matrix and the silicon phase, as the morphology of the silicon phase is affected by the heat treatment. A considerable scatter is observed in the neutron diffraction RS profiles, which is principally correlated to the presence (or absence) of pockets of porosity developed at the borders of the chessboard pattern.
KW - Neutron diffraction
KW - Additive manufacturing
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565115
DO - https://doi.org/10.1007/s10853-022-07997-w
SN - 1573-4803
VL - 57
SP - 22082
EP - 22098
PB - Springer Science + Business Media
CY - Dordrecht
AN - OPUS4-56511
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Miropoltsev, M.
A1 - Wegner, Karl David
A1 - Häusler, I.
A1 - Hodoroaba, Vasile-Dan
A1 - Resch-Genger, Ute
T1 - Influence of Hydrophilic Thiol Ligands of Varying Denticity on the Luminescence Properties and Colloidal Stability of Quaternary Semiconductor Nanocrystals
N2 - Binary photoluminescent semiconductor nanocrystals (quantum dots, QDs) are one of the best studied fluorescent nanomaterials, and their unique optoelectronic properties paved the road to many applications in (bio)nanophotonics, optoelectronics, and photovoltaics. However, concerns related to their toxic constituents like cadmium or lead and the emerging interest in greener chemistry synthesis approaches hamper their future applicability. Interesting alternatives for some applications like biosensing or bioimaging are heavy-metal-free ternary QDs like AgInS2 (AIS), CuInS2 (CIS), and quaternary QDs such as AIS-ZnS (ZAIS). In this context, we explored the effect of ligand denticity on the organic-to-aqueous phase transfer of oleylamine-stabilized ZAIS QDs with the hydrophilic ligands mercaptopropionic acid (MPA), dihydrolipoic acid (DHLA), and 3-mercapto-2,2-bis(mercaptomethyl)propanoic acid (3MPA), bearing mono-, bi-, and trialkyl thiol groups. Spectroscopic studies of the resulting water-dispersible ZAIS QDs revealed a considerable influence of ligand denticity and ligand-to-QD ratio on the spectral position and width (FWHM; full width at half-maximum) of the photoluminescence (PL) bands, the PL quantum yields (PL QY), and the PL decay kinetics. Thiol capping and phase transfer resulted in a loss in PL by at least a factor of 2. The ligand-induced PL quenching observed particularly for ligands bearing two or three thiol groups was attributed to the facilitated formation of surface-bound disulfides. The best colloidal stability under high dilution conditions was observed for 3MPA.
KW - Quantum dots
KW - Ligand exchange
KW - Lifetime analysis
KW - Thiols
PY - 2022
DO - https://doi.org/10.1021/acs.jpcc.2c05342
SN - 1932-7447
VL - 126
IS - 47
SP - 20101
EP - 20113
PB - ACS Publications
AN - OPUS4-56707
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Florian, Camilo
T1 - Influence of oxidation in the formation and performance of laser-induced periodic surface structures
N2 - The fabrication of laser-induced periodic surface structures (LIPSS) has been reported for metallic, semiconductor and dielectric materials when irradiated with linearly polarized ultrashort laser pulses. Different sets of processing parameters have been identified and extensively studied, allowing the use of LIPSS for applications in medicine, tribology and surface wetting to name a few. One important parameter that is often not considered is the laser-induced oxidation that is produced especially when oxidation prone materials are irradiated in air environment. This surface oxidation can potentially influence the final structures
size, shape and orientation and modify their functionality in some specific applications.
In this work, we first study the influence of the laser-induced oxidation layer on the formation of LIPSS by characterizing the response of the oxidation prone
hard-coating material chromium nitride. Moreover, we employ complementary surface and depth-profiling analytic techniques to reveal morphological, chemical and structural features of different types of surface structures and LIPSS produced on titanium-based substrates. Finite-difference time-domain (FDTD) calculations finally explain how this superficial oxidation layer promotes the formation of a new type of low spatial frequency LIPSS. Also, we measure the depth-extent of the different oxides formed and demonstrate its beneficial influence for friction reduction and wear resistance applications.
T2 - SPIE Photonics West Conference, Symposium "Laser-Based Micro- and Nano-Processing XVI"
CY - San Francisco, CA, USA
DA - 22.01.2022
KW - Laser-induced periodic surface structures (LIPSS)
KW - Oxidation
KW - Femtosecond laser
KW - Laser processing
KW - Finite-difference time-domain calculations (FDTD)
PY - 2022
AN - OPUS4-54322
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Goryacheva, O. A.
A1 - Wegner, Karl David
A1 - Sobolev, A. M.
A1 - Häusler, I.
A1 - Gaponik, N.
A1 - Gorycheva, I. Y.
A1 - Resch-Genger, Ute
T1 - Influence of particle architecture on the photoluminescence properties of silica‑coated CdSe core/shell quantum dots
N2 - Light-emitting nanoparticles like semiconductor nanocrystals (termed quantum dots, QDs) are promising candidates for biosensing and bioimaging applications based on their bright and stable photoluminescent properties. As high-quality QDs are often synthesized in organic solvents, strategies needed to be developed to render them water-dispersible without affecting their optical properties and prevent changes in postmodification steps like the biofunctionalization with antibodies or DNA. Despite a large number of studies on suitable surface modification procedures, the preparation of water-soluble QDs for nanobiotechnology applications still presents a challenge. To highlight the advantages of surface silanization, we systematically explored the influence of the core/multishell architecture of CdSe/CdS/ZnS QDs and the silanization conditions on the optical properties of the resulting silanized QDs. Our results show that the optical properties of silica-coated CdSe/CdS/ZnS QDs are best preserved in the presence of a thick CdS (6 monolayers (ML)) intermediate shell, providing a high photoluminescence quantum yield (PL QY), and a relatively thick ZnS (4.5 ML) external shell, effectively shielding the QDs from the chemical changes during silica coating. In addition to the QD core/shell architecture, other critical parameters of the silica-coating process, that can have an influence on the optical properties of the QD, include the choice of the surfactant and its concentration used for silica coating. The highest PL QY of about 46% was obtained by a microemulsion silica-coating procedure with the surfactant Brij L4, making these water-dispersible QDs to wellsuited optical reporters in future applications like fluorescence immunoassays, biomedicine, and bioimaging.
KW - Nano
KW - Nanomaterial
KW - Particle
KW - Semiconductor
KW - Quantum do
KW - Photoluminescence
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - Mechanism
KW - Surface
KW - Shell
KW - Silica
KW - Silanization
KW - Synthesis
PY - 2022
DO - https://doi.org/10.1007/s00216-022-04005-7
SP - 1
EP - 13
PB - Springer
AN - OPUS4-54546
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Knigge, Xenia
T1 - Influence of Sterilization on the Surface of Nanoparticles Studied with XPS / HAXPES in Comparison to SEM / EDS
N2 - Nanosafety is becoming increasingly important as nanomaterials are widely used in industrial processes and consumer products. For nanotoxicity measurements prior sterilization of the samples is necessary, but as structure activity relationships are made with properties of pristine particles, the question arises, if the sterilization process has an impact on the physico-chemical properties of nanoparticles and thus on the biological behavior.
This question will be addressed in this talk. For this purpose, results from SEM and EDS measurements are combined with those of a novel lab-based HAXPES spectrometer in order to obtain a more complete picture. At the end, an influence of sterilization will be evident, which indicates a restructuring of the nanoparticles owing to sterilization.
T2 - Microscopy & Microanalysis 2022
CY - Online meeting
DA - 31.07.2022
KW - XPS
KW - HAXPES
KW - SEM
KW - EDS
KW - Nanoparticles
PY - 2022
AN - OPUS4-55353
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Knigge, Xenia
A1 - Guo, Z.
A1 - Valsami-Jones, E.
A1 - Hodoroaba, Vasile-Dan
A1 - Radnik, Jörg
T1 - Influence of Sterilization on the Surface of Nanoparticles Studied with XPS / HAXPES in Comparison to SEM / EDS
N2 - Nanosafety is becoming increasingly important as nanomaterials are widely used in industrial processes and consumer products. For nanotoxicity measurements prior sterilization of the samples is necessary, but as structure activity relationships are made with properties of pristine particles, the question arises, if the sterilization process has an impact on the physico-chemical properties of nanoparticles and thus on the biological behavior.
This question will be addressed in this talk. For this purpose, results from SEM and EDS measurements are combined with those of a novel lab-based HAXPES spectrometer in order to obtain a more complete picture. At the end, an influence of sterilization will be evident, which indicates a restructuring of the nanoparticles owing to sterilization.
T2 - Microscopy & Microanalysis 2022
CY - Portland, USA
DA - 31.07.2022
KW - XPS
KW - HAXPES
KW - SEM
KW - EDS
KW - Nanoparticles
PY - 2022
DO - https://doi.org/10.1017/S1431927622004287
VL - 28
SP - 986
EP - 988
PB - Cambridge University Press
AN - OPUS4-55352
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Zhang, K.
A1 - Schmidt, Wolfram
A1 - Mezhov, Alexander
T1 - Influence of the hydroxypropylation of starch on its performance as viscosity modifying agent
N2 - Synopsis: Starch is a commonly used viscosity modifying agent (VMA). The performance of starch as VMA depends on its origin (e.g. potato, corn, cassava, etc.) and corresponding molecular properties, such as molecular weight, ratio between amylose and amylopectin etc. Depending upon the application, the efficiency of starch can be enhanced by hydroxypropylation. The maximum degree of substitution (DoS) cannot be greater than 3.0, which is the number of hydroxy groups per glucose monomer in the polymer. In the current research three potato starches exhibiting the DoS of 0.4, 0.6 and 0.8 were utilised. The influence of the modified starch on the rheological properties and hydration of cement paste, as well as the viscosity of the pore solution were investigated. Our findings show that the starch with the highest DoS increases the dynamic yield stress the most, while the plastic viscosity is less dependent on the DoS. Additionally, starch with the highest DoS retards hydration to lower degree than other starches.
T2 - 13th International Conference on Superplasticizers and Other Chemical Admixtures in Concrete
CY - Milan, Italy
DA - 10.07.2022
KW - Potato starch
KW - Rheological
KW - Cement hydration
KW - Pore solutions
PY - 2022
DO - https://doi.org/10.14359/51736074
VL - 354
SP - 209
EP - 218
PB - ACI Special Publications
AN - OPUS4-58320
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Smekhova, A.
A1 - Kuzmin, A.
A1 - Siemensmeyer, K.
A1 - Abrudan, R.
A1 - Reinholz, Uwe
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Schneider, M.
A1 - Laplanche, G.
A1 - Yusenko, Kirill
T1 - Inner relaxations in equiatomic single-phase high-entropy Cantoralloy
N2 - The superior properties of high-entropy multi-functional materials are strongly connected with their atomic heterogeneity through many different local atomic interactions. The detailed element-specific studies on a local scale can provide insight into the primary arrangements of atoms in multicomponent systems and benefit to unravel the role of individual components in certain macroscopic properties of complex compounds. Herein, multi-edge X-ray absorption spectroscopy combined with reverse Monte Carlo simulations was used to explore a homogeneity of the local crystallographic ordering and specific structure relaxations of each constituent in the equiatomic single-phase facecentered cubic CrMnFeCoNi high-entropy alloy at room temperature. Within the considered fitting approach, all five elements of the alloy were found to be distributed at the nodes of the fcc lattice without any signatures of the additional phases at the atomic scale and exhibit very close statistically averaged interatomic distances (2.54 – 2.55 Å) with their nearest-neighbors. Enlarged structural displacements were found solely for Cr atoms. The macroscopic magnetic properties probed by conventional magnetometry demonstrate no opening of the hysteresis loops at 5 K and illustrate a complex character of the long-range magnetic order after field-assisted cooling in ± 5 T. The observed magnetic behavior is assigned to effects related to structural relaxations of Cr. Besides, the advantages and limitations of the reverse Monte Carlo approach to studies of multicomponent systems like high-entropy alloys are highlighted.
KW - Magnetism
KW - High-entropy alloys
KW - Reverse Monte Carlo (RMC)
KW - Element-specific spectroscopy
KW - Extended X-ray absorption fine structure (EXAFS)
KW - X-ray absorption near edge structure (XANES)
PY - 2022
DO - https://doi.org/10.1016/j.jallcom.2022.165999
SN - 0925-8388
VL - 920
SP - 1
EP - 31
PB - Elsevier
AN - OPUS4-55457
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ciornii, Dmitri
T1 - Interlaboratory Comparisons – ILCs (2022-2023)
N2 - To obtain reliable data on micro- and nanoplastics (MPs, NPs) BAM (Federal Institute for Materials Research and Testing) is organizing interlaboratory comparisons (ILCs). Main focus is detection and physico-chemical characterisation. The accuracy and precision of the results of different laboratories and comparability of the results among the participants are addressed. The ILCs will be performed in the following order: i) ILC #1: Detection and Characterisation of MPs (1-1000 µm) and ii) ILC #2: Detection and Characterisation of NPs (< 1 µm).
For the ILC #1 the parameters to be analysed are: particle size distribution, shape, mass content, particle concentration, with thermoanalytic (Py-GC/MS, TED-GC/MS) and spectroscopy (µ-Raman, µ-FTIR) methods. For the ILC #2 the parameters are: particle size distribution, shape, particle concentration, with methods such as spectroscopical (Raman), Electron Microscopies (SEM, AFM), etc. Exact measurands and methods are still under discussion. BAM will provide test materials of well-known stability and homogeneity. ILC participants will include partners of the CUSP (the European research cluster to understand the health impacts of micro- and nanoplastics), and any other institutions over the world. The ILCs will take place under the international pre-standardisation platform VAMAS, new Technical Working Area 35 “Micro and Nano Plastics in the Environment” (http://www.vamas.org/twa45/).
T2 - Progressing Together: 2nd CUSP Annual Meeting at the JRC (Ispra)
CY - Ispra, Italy
DA - 08.06.2022
KW - ILC
KW - Micro- and nanoplastics
KW - VAMAS
KW - Analytical methods
PY - 2022
AN - OPUS4-55097
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Roveda, Ilaria
A1 - Serrano-Munoz, Itziar
A1 - Kromm, Arne
A1 - Madia, Mauro
T1 - Investigation of residual stresses and microstructure effects on the fatigue behaviour of a L-PBF AlSi10Mg alloy
N2 - Al-Si alloys produced by Laser Powder Bed Fusion (L-PBF) techniques allow the fabrication of lightweight free-shape components that find space in aerospace, automotive, biomedical and military applications. Due to the high cooling rates occurring during the building process, L-PBF AlSi10Mg alloys exhibit an ultra-fine microstructure that leads to superior mechanical properties in the as-built condition compared to conventional cast Al-Si materials. Nevertheless, L-PBF processing induces high thermal gradients, leading to deleterious residual stress levels that must be considered to avoid part distortion and unpredicted failures. In order to relax detrimental residual stress and to increase the ductility, post-processing stress relief treatments are generally performed. In as-built condition the hypoeutectic AlSi10Mg microstructure consist of fine α-Al cells containing uniformly dispersed silicon nanoparticles, which are, in addition, surrounded by a eutectic Si network. Above 260°C the silicon interconnectivity starts to breakdown into spheroidized particles and to coarsen. At the same time, the heating residual stresses are relieved.
The objective of the contribution is to investigate, under different heat treatment conditions, the evolution of microstructure and residual stresses in view of optimizing the fatigue performance of the alloy. To this purpose various heat treatments in a range of temperatures between 265°C and 300°C for a duration between 15 minutes and 2 hours are performed. The microstructure modifications are analysed using a scanning electron microscope and the residual stress state is measured by laboratory X-ray diffraction.
T2 - FATIGUE DESIGN 2021
CY - Online meeting
DA - 17.11.2021
KW - AlSi10Mg alloy
KW - Additive manufacturing
KW - L-PBF
KW - Residual stress
KW - Heat treatment
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544942
DO - https://doi.org/10.1016/j.prostr.2022.03.057
SN - 2452-3216
VL - 38
SP - 564
EP - 571
PB - Elsevier B.V.
AN - OPUS4-54494
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Xu, C.
A1 - Battig, Alexander
A1 - Schartel, Bernhard
A1 - Siegel, R.
A1 - Senker, J.
A1 - von der Forst, I.
A1 - Unverzagt, C.
A1 - Agarwal, S.
A1 - Möglich, A.
A1 - Greiner, A.
T1 - Investigation of the Thermal Stability of Proteinase K for the Melt Processing of Poly(L‑lactide)
N2 - The enzymatic degradation of aliphatic polyesters offers unique opportunities for various use cases in materials science. Although evidently desirable, the implementation of enzymes in technical applications of polyesters is generally challenging due to the thermal lability of enzymes. To prospectively overcome this intrinsic limitation, we here explored the thermal stability of proteinase K at conditions applicable for polymer melt processing, given that this hydrolytic enzyme is well established for its ability to degrade poly(L-lactide) (PLLA). Using assorted spectroscopic methods and enzymatic assays, we investigated the effects of high temperatures on the structure and specific activity of proteinase K. Whereas in solution, irreversible unfolding occurred at temperatures above 75−80 °C, in the dry, bulk state, proteinase K withstood prolonged incubation at elevated temperatures. Unexpectedly little activity loss occurred during incubation at up to 130 °C, and intermediate levels of catalytic activity were preserved at up to 150 °C. The resistance of bulk proteinase K to thermal treatment was slightly enhanced by absorption into polyacrylamide (PAM) particles. Under these conditions, after 5 min at a temperature of 200 °C, which is required for the melt processing of PLLA, proteinase K was not completely denatured but retained around 2% enzymatic activity. Our findings reveal that the thermal processing of proteinase K in the dry state is principally feasible, but equally, they also identify needs and prospects for improvement. The experimental pipeline we establish for proteinase K analysis stands to benefit efforts directed to this end. More broadly, our work sheds light on enzymatically degradable polymers and the thermal processing of enzymes, which are of increasing economical and societal relevance.
KW - Enzymatic degradation
KW - Poly(L‑lactide)
KW - Polyesters
KW - biodegradation
PY - 2022
DO - https://doi.org/10.1021/acs.biomac.2c01008
SN - 1525-7797
SN - 1526-4602
VL - 23
IS - 11
SP - 4841
EP - 4850
PB - ACS Publications
AN - OPUS4-56292
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Arnold, M.
A1 - Katzmann, J.
A1 - Naik, Aakash
A1 - Görne, A. L.
A1 - Härtling, Thomas
A1 - George, Janine
A1 - Schuster, C.
T1 - Investigations on electron beam irradiated rare-earth doped SrF2 for application as low fading dosimeter material: Evidence for and DFT simulation of a radiation-induced phase
N2 - A recent approach to measure electron radiation doses in the kGy range is the use of phosphors with an irradiation dose-dependent luminescence decay time. However, the applicability of the previously investigated material NaYF4:Yb3+,Er3+ is limited as it shows pronounced fading. Therefore, in this work, a modified SrF2 synthesis is presented that results in SrF2 nanoparticles codoped with Yb and either Er, Hm, or Tm. To assess their suitability as dosimeter material, dose response, as well as its degree of fading over 50 up to 140 days after irradiation were measured. Fading rates as small as 5% in SrF2:Er,Yb and 4% in SrF2:Ho,Yb were derived, which are comparable to established dosimeter materials. A combination of spectroscopy, diffraction and DFT calculations was used to elucidate the effect of irradiation, pointing towards the formation of a secondary phase of Yb2+ that we predict could be Yb2OF2. This irreversible formation of a secondary phase is considered to be the explanation for the low fading behavior in SrF2-based phosphors compared to NaYF4:Yb, Er, a highly attractive feature for electron beam dosimetry.
KW - DFT
KW - Structure prediction
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554115
DO - https://doi.org/10.1039/D2TC01773C
SN - 2050-7526
VL - 10
IS - 32
SP - 11579
EP - 11587
PB - RSC
CY - London
AN - OPUS4-55411
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Mehmood, Asad
T1 - Ionothermal Template Transformation as a Sustainable Route Towards Carbon Electrodes in Energy Storage and Conversion
N2 - Porous carbons with tuneable functionalities and morphologies have extensively been employed as electrode materials in a variety of electrochemical energy conversion and storage systems for instance in fuel cells and electrolysers as active catalysts and catalyst supports, and in secondary batteries as anode materials. Amorphous carbons with well-developed pore structures are of particular interest due to their superior mass-transport characteristics and remarkable charge storage capacities. The salt-templating method with its advantage of combined soft and hard templating effects provides a sustainable way to synthesize nano- and mesoporous carbons with tailored porosities via in-situ ionothermal template transformation [1]. In this work, we utilized a MgCl2-based salt melt to prepare nitrogen doped carbons (N-C) with different morphologies and porosities, which were evaluated as anode materials in sodium ion batteries. Simultaneously, use of MgCl2 salt leads to the formation of Mg-N4 moieties in those carbons by means of a pyrolytic template-ion effect (active site imprinting) [2]. Porous carbon frameworks with imprinted Mg-N4 sites are interesting particularly for electrocatalysis applications as they offer an ideal platform to prepare M-N-C catalysts (where M= Co, Fe, Ni etc.) by ion-exchange reactions at low temperatures. The resultant M-N-C catalysts consist purely of M-N4 active sites and high porosity of carbon framework facilitates efficient mass-transport of reacting species.
We utilized Mg-N4 imprinted carbons to synthesize morphologically equivalent Ni-N-Cs and Co-N-Cs, containing phase pure Ni-N4 and Co-N4 sites, for electrochemical reduction of carbon dioxide (CO2RR). In electrochemical tests, Ni-N-Cs exhibited an excellent CO2 reduction activity with considerably higher CO selectivity and mass activity as compared to Co-N-C. The faradic efficiency value of Ni-N-C for CO formation was 95% at U= -0.5 to -0.8 VRHE (vs reversible hydrogen electrode) and a mass activity of 23 A g-1. The performance stability test carried out at -0.65 VRHE demonstrated above 90 % retention of the current density and CO selectivity after 100 h of continuous operation, reflecting the structural robustness of the Ni-N-C catalyst.
Finally, these ionothermal carbons with two different morphologies (but without any Ni or Co incorporation) were employed as the anode materials in sodium-ion batteries to evaluate the effects of carbon morphology and functionalization on sodium storage capacities. Compared to the reference carbon material, substantially higher reversible sodium storage capacities were reached with these high porosity carbons that were in the range of 300-500 mAh g-1 [3]. Although the reversible capacity was obtained only after extensive SEI formation, our results reveal the potential for much higher reversible capacities than usually observed using carbons with a tailored porosity in sodium-ion batteries. The talk will include greater details of the structural analysis and sodium storage and CO2 reduction results of these ionothermal carbons.
T2 - Materials for Sustainable Development Conference (MAT-SUS)
CY - Barcelona, Spain
DA - 24.10.2022
KW - Porous carbons
KW - Sodium ion batteries
KW - Anode materials
KW - Single atom catalysts
KW - Electrochemical CO2 reduction
PY - 2022
AN - OPUS4-61985
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Guo, Y.
A1 - Ren, K.
A1 - Wei, A.
A1 - Tao, C.
A1 - Huang, W.
A1 - Zhao, Peng
A1 - Wu, Dejian
T1 - Iron dust explosion characteristics with small amount of nano-sized Fe2O3 and Fe3O4 particles
N2 - Iron powder, as one of the most abundant metal fuels that can be used as recyclable carriers of clean energy, is a promising alternative to fossil fuels in a future low-carbon economy. It may pose a potential explosion hazard during the process of processing, storage, transport, and reduction/oxidation (redox). The explosion characteristics of iron dust in air were undertaken via a 20 L spherical explosion chamber with an emphasis on minimum explosion concentration (MEC) of iron dust. The alternative method of combustion duration time (tc) was used to determine MEC and compared with the standardized over pressure method. Two kinds of nano-sized iron oxides (Fe2O3 and Fe3O4) were used as inertants to determine the inhibition effect of different oxidation products. The iron dust explosion products with various shapes and sizes were found to be able to grow up 4–6 times of the iron dust for the first time. Adding small amount of Fe2O3 or Fe3O4 could reduce the explosion severity and sensitivity of iron dust. The MEC data determined by both methods were comparable. The addition of 5 % oxide has obvious inhibition effect under 1500 g/m3 concentration. With the increase of oxide concentration to 10 %, the inerting effect increases, and the MEC of iron dust increases more than 3 times. The increase of dust concentration will weaken the inerting effect. When the concentration increases from 500 g/m3 to 3000 g/m3, the weakening effect of 10 % Fe2O3 on the explosion pressure decreases from 38.45 % to 2.24 %, and 10 % Fe3O4 decreases from 46.21 % to 10.63 %. Unlike coal, biomass or aluminum dusts, the iron dust explosion was found to have a unique secondary acceleration of pressure rise rate for the first time. These results provide a fundamental basis to mitigate the iron dust explosion via solid inerting method without adding extra elements.
KW - Iron dust
KW - Iron oxides
KW - MEC
KW - Combustion duration time
KW - Explosion products
KW - Pressure rise rate
PY - 2022
DO - https://doi.org/10.1016/j.fuel.2022.124786
SN - 0016-2361
VL - 324, Part C
SP - 1
EP - 13
PB - Elsevier Ltd.
AN - OPUS4-55057
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kader, A.
A1 - Kaufmann, Jan Ole
A1 - Mangarova, D. B.
A1 - Moeckel, J.
A1 - Brangsch, J.
A1 - Adams, L. C.
A1 - Zhao, J.
A1 - Reimann, C.
A1 - Saatz, Jessica
A1 - Traub, Heike
A1 - Buchholz, R.
A1 - Karst, U.
A1 - Hamm, B.
A1 - Makowski, M. R.
T1 - Iron Oxide Nanoparticles for Visualization of Prostate Cancer in MRI
N2 - Prostate cancer (PCa) is one of the most common cancers in men. For detection and diagnosis of PCa, non-invasive methods, including magnetic resonance imaging (MRI), can reduce the risk potential of surgical intervention. To explore the molecular characteristics of the tumor, we investigated the applicability of ferumoxytol in PCa in a xenograft mouse model in two different tumor volumes, 500 mm3 and 1000 mm3. Macrophages play a key role in tumor progression, and they are able to internalize iron-oxide particles, such as ferumoxytol. When evaluating T2*-weighted sequences on MRI, a significant decrease of signal intensity between pre- and post-contrast images for each tumor volume (n = 14; p < 0.001) was measured. We, furthermore, observed a higher signal loss for a tumor volume of 500 mm3 than for 1000 mm3. These findings were confirmed by histological examinations and laser ablation inductively coupled plasma-mass spectrometry. The 500 mm3 tumors had 1.5% iron content (n = 14; sigma = 1.1), while the 1000 mm3 tumors contained only 0.4% iron (n = 14; sigma = 0.2). In vivo MRI data demonstrated a correlation with the ex vivo data (R2 = 0.75). The results of elemental analysis by inductively coupled plasma-mass spectrometry correlated strongly with the MRI data (R2 = 0.83) (n = 4). Due to its long retention time in the blood, biodegradability, and low toxicity to patients, ferumoxytol has great potential as a contrast agent for visualization PCa.
KW - Imaging
KW - Nanoparticle
KW - Cancer
KW - Iron oxide
KW - ICP-MS
KW - Magnetic resonance imaging
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550075
DO - https://doi.org/10.3390/cancers14122909
VL - 14
IS - 12
SP - 1
EP - 13
PB - MDPI
CY - Basel, Switzerland
AN - OPUS4-55007
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gupta, P.
A1 - Karnaushenko, D. D.
A1 - Becker, C.
A1 - Okur, I. E.
A1 - Melzer, Michael
A1 - Özer, B.
A1 - Schmidt, O. G.
A1 - Karnaushenko, D.
T1 - Large Scale Exchange Coupled Metallic Multilayers by Roll-to-Roll (R2R) Process for Advanced Printed Magnetoelectronics
N2 - Till now application of printed magnetoelectronics is hindered by lack of large area exchange coupled metallic multilayers required to produce printable magneto-sensory inks. Large-scale roll-to-roll (R2R) fabrication process is an attractive approach owing to its capabilities for high volume, high throughput, and large area manufacturing. Precise and high performance R2R sputtering technology is developed to fabricate large area giant magnetoresistive (GMR) thin-films stacks that contain 30 metallic bilayers prepared by continuous R2R sputtering of Co and Cu sequential on a hundred meters long polyethylene terephthalate (PET) web. The R2R sputtered Co/Cu multilayer on a 0.2 × 100 m2 PET web exhibits a GMR ratio of ≈40% achieving the largest area exchange coupled room temperature magneto-sensitive system demonstrated to date. The prepared GMR thin-film is converted to magnetosensitive ink that enables printing of magnetic sensors with high performance in a cost-efficient way, which promotes integration with printed electronics. An average GMR ratio of ≈18% is obtained for 370 printed magnetic sensors. The realized precise R2R sputtering approach can also be extended to a wide range of hybrid thin-film material systems opening up a path for new functional inks applied with printing technologies.
KW - Printed Electronics
KW - Flexible Magnetic Sensors
KW - Roll-to-Roll Processing
KW - Functional Materials
KW - Upscaling
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552344
DO - https://doi.org/10.1002/admt.202200190
SN - 2365-709X
SP - 1
EP - 11
PB - Wiley-VCH
CY - Weinheim, Deutschland
AN - OPUS4-55234
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kornev, R. A.
A1 - Sennikov, P. G.
A1 - Gornushkin, Igor B.
A1 - Ermakov, A. A.
A1 - Shkrunin, V. E.
A1 - Polykov, V. S.
A1 - Kornev, A. R.
A1 - Kornev, K. D.
T1 - Laser induced dielectric breakdown as a novel method for the synthesis of molybdenum boride
N2 - Laser induced dielectric breakdown (LIDB) on a surface of solid Mo in H2/BF3 atmosphere at 30-760 Torr and in a gaseous mixture MoF6/H2/BF3 + at 760 Torr pressure is tested for synthesis and deposition of superhard molybdenum borides that are needed in many areas of industry and technology. The emission spectra of the plasma and the dynamics of the gas discharge near the substrate are investigated. A comparative analysis of the gas mixture before and after exposure to LIDB plasma is carried out using IR spectroscopy. The conditions for the formation of molybdenum borides are determined. A thermodynamic analysis of the MoF6/H2/BF3 and Mo/H2/BF3 systems is carried out to determine the temperature range for the formation of molybdenum borides and establish the main chemical reactions responsible for their formation. Deposits containing MoB and MoB2 phases are obtained. For the mixture MoF6/H2/BF3, the deposit exhibits an amorphous layered structure, which contains 19.15 wt% F, 30.45% O, and 0.8% Si. For the Mo/H2/BF3 system at the pressures 30 and 160 Torr, nanopowder of molybdenum boride is produced with a characteristic grain size of 100 nm. At pressures above 160 Torr, Mo nanopowder with a grain size <30 nm is obtained.
KW - LIDB plasma
KW - MoF6
KW - BF3
KW - Hydrogen reduction
KW - Molybdenum boride
PY - 2022
DO - https://doi.org/10.1007/s11090-021-10224-0
SN - 1572-8986
SP - 1
EP - 18
PB - Springer
CY - Dordrecht
AN - OPUS4-54290
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Bonse, Jörn
T1 - Laser-induced Periodic Surface Structures (LIPSS): Mechanisms, Applications, and unsolved Problems
N2 - Laser-induced Periodic Surface Structures (LIPSS, ripples) are a universal phenomenon and can be generated in a contactless, single-step process on almost any type of solid upon irradiation with intense laser pulses. They represent a (quasi-)periodic modulation of the surface topography in the form of a linear grating and are typically formed in a “self-ordered” way in the focus of a laser beam. Thus, they are often accompanying laser material processing applications. The structural sizes of LIPSS typically range from several micrometers down to less than 100 nanometers – far beyond the optical diffraction limit – while their orientations exhibit a clear correlation with the local polarization direction of the laser radiation. From a theoretical point of view, a controversial debate has emerged during the last decades, whether LIPSS originate from electromagnetic effects (seeded already during the laser irradiation) – or whether they emerge from matter-reorganization processes (distinctly after the laser irradiation). From a practical point of view, however, LIPSS represent a simple and robust way for the nanostructuring of solids that allows creating a wide range of different surface functionalities featuring applications in optics, tribology, medicine, energy technologies, etc. While the currently available laser and scanner technology already allows surface processing rates at the m^2/min level, industrial applications of LIPSS are sometimes limited by the complex interplay between the nanoscale surface topography and the specific surface chemistry. This typically manifests in difficulties to control the processing of LIPSS and in limitations to ensure the long-term stability of the created surface functions. This presentation reviews the currently existent theories of LIPSS. A focus is laid on the historic development of the fundamental ideas behind the LIPSS, their corresponding mathematical descriptions and numerical implementations, along with a comparison and critical assessment of the different approaches. Moreover, some unsolved scientific problems related to LIPSS are identified and the pending technological limitations are discussed. Hereby, it is intended to stimulate further research and developments in the field of LIPSS for overcoming these limitations and for supporting the transfer of the LIPSS technology into industry
T2 - 10th International LIPSS Workshop 2022
CY - Orléans, France
DA - 21.09.2022
KW - Laser-induced periodic surface structures (LIPSS)
KW - Surface functionalization
KW - Femtosecond laser processing
KW - Time-resolved coherent scattering
PY - 2022
AN - OPUS4-55814
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Bonse, Jörn
T1 - Laser-induced Periodic Surface Structures - Mechanisms, Applications, and unsolved Problems
N2 - Laser-induced Periodic Surface Structures (LIPSS, ripples) are a universal phenomenon and can be generated in a contactless, single-step process on almost any type of solid upon irradiation with intense laser pulses. They represent a (quasi-)periodic modulation of the surface topography in the form of a linear grating and are typically formed in a “self-ordered” way in the focus of a laser beam. Thus, they are often accompanying laser material processing applications. The structural sizes of LIPSS typically range from several micrometers down to less than 100 nanometers – far beyond the optical diffraction limit – while their orientations exhibit a clear correlation with the local polarization direction of the laser radiation. From a theoretical point of view, a controversial debate has emerged during the last decades, whether LIPSS originate from electromagnetic effects (seeded already during the laser irradiation) – or whether they emerge from matter-reorganization processes (distinctly after the laser irradiation). From a practical point of view, however, LIPSS represent a simple and robust way for the nanostructuring of solids that allows creating a wide range of different surface functionalities featuring applications in optics, tribology, medicine, energy technologies, etc. While the currently available laser and scanner technology already allows surface processing rates at the m^2/min level, industrial applications of LIPSS are sometimes limited by the complex interplay between the nanoscale surface topography and the specific surface chemistry. This typically manifests in difficulties to control the processing of LIPSS and in limitations to ensure the long-term stability of the created surface functions. This presentation reviews the currently existent theories of LIPSS. A focus is laid on the historic development of the fundamental ideas behind the LIPSS, their corresponding mathematical descriptions and numerical implementations, along with a comparison and critical assessment of the different approaches. Moreover, some unsolved scientific problems related to LIPSS are identified and the pending technological limitations are discussed. Hereby, it is intended to stimulate further research and developments in the field of LIPSS for overcoming these limitations and for supporting the transfer of the LIPSS technology into industry.
T2 - SPIG 2022 - 31st Summer School and International Symposium on the Physics of Ionized Gases
CY - Belgrade, Serbia
DA - 05.09.2022
KW - Laser-induced periodic surface structures (LIPSS)
KW - Surface functionalization
KW - Femtosecond laser processing
PY - 2022
AN - OPUS4-55813
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lifka, S.
A1 - Harsányi, K.
A1 - Baumgartner, E.
A1 - Pichler, L.
A1 - Baiko, D.
A1 - Wasmuth, Karsten
A1 - Heitz, J.
A1 - Meyer, M.
A1 - Joel, A.-C.
A1 - Bonse, Jörn
A1 - Baumgartner, W.
ED - Mail, M.
T1 - Laser-processed antiadhesive bionic combs for handling nanofibers inspired by nanostructures on the legs of cribellate spiders
N2 - Nanofibers are drawing the attention of engineers and scientists because their large surface-to-volume ratio is favorable for applications in medicine, filter technology, textile industry, lithium-air batteries, and optical sensors. However, when transferring nanofibers to a technical product in the form of a random network of fibers, referred to as nonwoven fabric, the stickiness of the freshly produced and thus fragile nanofiber nonwoven remains a problem. This is mainly because nanofibers strongly adhere to any surface because of van der Waals forces. In nature, there are animals that are actually able to efficiently produce, process, and handle nanofibers, namely cribellate spiders. For that, the spiders use the calamistrum, a comb-like structure of modified setae on the metatarsus of the hindmost (fourth) legs, to which the 10–30 nm thick silk nanofibers do not stick due to a special fingerprint-like surface nanostructure. In this work, we present a theoretical model of the interaction of linear nanofibers with a sinusoidally corrugated surface. This model allows for a prediction of the adhesive interaction and, thus, the design of a suitable surface structure to prevent sticking of an artificially nonwoven of nanofibers. According to the theoretical prediction, a technical analogon of the nanoripples was produced by ultrashort pulse laser processing on different technically relevant metal surfaces in the form of so-called laser-induced periodic surface structures (LIPSS). Subsequently, by means of a newly established peel-off test, the adhesion of an electrospun polyamide fiber-based nonwoven was quantified on such LIPSS-covered aluminium alloy, steel, and titanium alloy samples, as well as on polished (flat) control samples as reference and, additionally, on samples with randomly rough surfaces. The latter revealed that the adhesion of electrospun nanofiber nonwoven is significantly lowered on the nanostructured surfaces compared with the polished surfaces.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Cribellate spiders
KW - Calamistrum
KW - Electrospinning
KW - Nanofibers
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561799
DO - https://doi.org/10.3762/bjnano.13.105
SN - 2190-4286
VL - 13
SP - 1268
EP - 1283
PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften
CY - Frankfurt, M.
AN - OPUS4-56179
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hodoroaba, Vasile-Dan
T1 - Liaison report from VAMAS with ISO/TC 202 Microbeam Analysis
N2 - The progress in the activities on Microbeam Analysis under VAMAS/TWA 37 is reviewed. Particularly the liaison with the new projects within the ISO technical committee TC 202 is presented and discussed with respect to the possibility of identifying and launching related VAMAS projects/inter-laboratory comparisons. The recently started project FIB sample processing for TEM is presented. Next projects in the pipeline involving EBSD and TKD are shortly announced. The need of more promotion for the engagement of more experts from industry and academia at national, European and international level is highlighted. Also, the competition with the other technical working areas (on 'nano' or materials-related) is critically discussed.
T2 - 29th Annual Meeting of ISO/TC 202 Microbeam Analysis
CY - Online meeting
DA - 28.11.2022
KW - VAMAS
KW - ISO/TC 202
KW - Microbeam Analysis
KW - EBSD
KW - Electron microscopy
KW - Thin films
PY - 2022
AN - OPUS4-56424
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Spallanzani, Roberta
A1 - Koga, K.
A1 - Cichy, S.
A1 - Wiedenbeck, M.
A1 - Schmidt, B.
A1 - Oelze, Marcus
A1 - Wilke, M.
T1 - Lithium and boron difusivity and isotopic fractionation in hydrated rhyolitic melts
N2 - Lithium and boron are trace components of magmas, released during exsolution of a gas phase during volcanic activity. In this study, we determine the difusivity and isotopic fractionation of Li and B in hydrous silicate melts. Two glasses were synthesized with the same rhyolitic composition (4.2 wt% water), having diferent Li and B contents; these were studied in difusion-couple experiments that were performed using an internally heated pressure vessel, operated at 300 MPa in the temperature range 700–1250 °C for durations from 0 s to 24 h. From this we determined activation energies for Li and B difusion of 57±4 kJ/mol and 152±15 kJ/mol with pre-exponential factors of 1.53 × 10–7 m2/s and 3.80× 10–8 m2 /s, respectively. Lithium isotopic fractionation during difusion gave β values between 0.15 and 0.20, whereas B showed no clear isotopic fractionation. Our Li difusivities and isotopic fractionation results difer somewhat from earlier published values, but overall confrm that Li difusivity increases with water content. Our results on B difusion show that similarly to Li, B mobility increases in the presence of water. By applying the Eyring relation, we confrm that B difusivity is limited by viscous fow in silicate melts. Our results on Li and B difusion present a new tool for understanding degassing-related processes, ofering a potential geospeedometer to measure volcanic ascent rates.
KW - Hydrated silicate melts
KW - Stable isotopes
KW - Diffusion
KW - Isotopic fractionation
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554496
DO - https://doi.org/10.1007/s00410-022-01937-2
VL - 177
IS - 8
SP - 1
EP - 17
PB - Springer
AN - OPUS4-55449
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Smekhova, A.
A1 - Kuzmin, A.
A1 - Siemensmeyer, K.
A1 - Luo, C.
A1 - Taylor, J.
A1 - Thakur, S.
A1 - Radu, F.
A1 - Weschke, E.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Xiao, B.
A1 - Savan, A.
A1 - Yusenko, Kirill
A1 - Ludwig, A.
T1 - Local structure and magnetic properties of a nanocrystalline Mn-rich Cantor alloy thin film down to the atomic scale
N2 - The huge atomic heterogeneity of high-entropy materials along with a possibility to unravel the behavior of individual components at the atomic scale suggests a great promise in designing new compositionally complex systems with the desired multi-functionality. Herein, we apply multi-edge X-ray absorption spectroscopy (extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES), and X-ray magnetic circular dichroism (XMCD)) to probe the structural, electronic, and magnetic properties of all individual constituents in the single-phase face-centered cubic (fcc)-structured nanocrystalline thin film of Cr20Mn26Fe18Co19Ni17 (at.%) high-entropy alloy on the local scale. The local crystallographic ordering and component-dependent lattice displacements were explored within the reverse Monte Carlo approach applied to EXAFS spectra collected at the K absorption edges of several constituents at room temperature. A homogeneous short-range fcc atomic environment around the absorbers of each type with very similar statistically averaged interatomic distances (2.54–2.55 Å) to their nearest-neighbors and enlarged structural relaxations of Cr atoms were revealed. XANES and XMCD spectra collected at the L2,3 absorption edges of all principal components at low temperature from the oxidized and in situ cleaned surfaces were used to probe the oxidation states, the changes in the electronic structure, and magnetic behavior of all constituents at the surface and in the sub-surface volume of the film. The spin and orbital magnetic moments of Fe, Co, and Ni components were quantitatively evaluated. The presence of magnetic phase transitions and the co-existence of different magnetic phases were uncovered by conventional magnetometry in a broad temperature range.
KW - Magnetism
KW - High-entropy alloys
KW - Reverse Monte Carlo (RMC)
KW - Element-specific spectroscopy
KW - Extended X-ray absorption fine structure (EXAFS),
KW - X-ray magnetic circular dichroism (XMCD),
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578254
DO - https://doi.org/10.1007/s12274-022-5135-3
SN - 1998-0124
SP - 5626
PB - Springer
AN - OPUS4-57825
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bresch, Sophie
A1 - Mieller, Björn
A1 - Moos, R.
A1 - Rabe, Torsten
T1 - Lowering the sintering temperature of calcium manganate for thermoelectric applications
N2 - This study combines three different approaches to lower the sintering temperature of Sm-doped CaMnO3 to save energy in production and facilitate co-firing with other low-firing oxides or metallization. The surface energy of the powder was increased by fine milling, sintering kinetics were enhanced by additives, and uniaxial pressure during sintering was applied. The shrinkage, density, microstructure, and thermoelectric properties were evaluated. Compared to micro-sized powder, the use of finely ground powder allows us to lower the sintering temperature by 150 K without reduction of the power factor. By screening the effect of various common additives on linear shrinkage of CaMnO3 after sintering at 1100 ○C for 2 h, CuO is identified as the most effective additive. Densification at sintering temperatures below 1000 ○C can be significantly increased by pressure-assisted sintering. The power factor at room temperature of CaMnO3 nano-powder sintered at 1250 ○C was 445 μW/(m K2). Sintering at 1100 ○C reduced the power factor to 130 μW/(m K2) for CaMnO3 nano-powder, while addition of 4 wt.% CuO to the same powder led to ∼290 μW/(m K2). The combination of fine milling, CuO addition, and pressureassisted sintering at 950 ○C resulted in a power factor of ∼130 μW/(m K2). These results show that nano-sized powder and CuO addition are successful and recommendable strategies to produce CaMnO3 with competitive properties at significantly reduced temperatures and dwell times.
KW - Sintering additive
KW - Liquid phase sintering
KW - Pressure assisted sintering
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555467
DO - https://doi.org/10.1063/5.0098015
SN - 2158-3226
VL - 12
IS - 8
SP - 1
EP - 9
PB - American Institute of Physics (AIP)
CY - New York, NY
AN - OPUS4-55546
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Scholtz, Lena
T1 - Luminescence encoding of polymer microbeads with nanocrystals during polymerization
N2 - The Goal & Motivation
- Spherical polymer beads
- Controlled size in the low µm range
- Narrow size distribution
- Homogeneous encoding with molecular and nanoscale luminophores (dyes , QDs, platelets etc.)
- Sufficient fluorescence
- Easy, accessible procedure
T2 - GrK Nanohybrid Conference
CY - Hamburg, Germany
DA - 04.10.2022
KW - Polymerization
KW - Nanocrystals
KW - Fluorescence
KW - Microbeads
PY - 2022
AN - OPUS4-56028
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scholtz, Lena
A1 - Eckert, J. G.
A1 - Elahi, T.
A1 - Lübkemann, F.
A1 - Hübner, Oskar
A1 - Bigall, N. C.
A1 - Resch-Genger, Ute
T1 - Luminescence encoding of polymer microbeads with organic dyes and semiconductor quantum dots during polymerization
N2 - Luminescence-encoded microbeads are important tools for many applications in the life and material sciences that utilize luminescence detection as well as multiplexing and barcoding strategies. The preparation of such beads often involves the staining of premanufactured beads with molecular luminophores using simple swelling procedures or surface functionalization with layer-by-layer (LbL) techniques. Alternatively, these luminophores are sterically incorporated during the polymerization reaction yielding the polymer beads. The favorable optical properties of semiconductor quantum dots (QDs), which present broadly excitable, size-tunable, narrow emission bands and low photobleaching sensitivity, triggered the preparation of beads stained with QDs. However, the colloidal nature and the surface chemistry of these QDs, which largely controls their luminescence properties, introduce new challenges to bead encoding that have been barely systematically assessed. To establish a straightforward approach for the bead encoding with QDs with minimized loss in luminescence, we systematically assessed the incorporation of oleic acid/oleylamine-stabilized CdSe/CdS-core/shell-QDs into 0.5–2.5 μm-sized polystyrene (PS) microspheres by a simple dispersion polymerization synthesis that was first optimized with the organic dye Nile Red. Parameters addressed for the preparation of luminophore-encoded beads include the use of a polymer-compatible ligand such as benzyldimethyloctadecylammonium chloride (OBDAC) for the QDs, and crosslinking to prevent luminophore leakage. The physico-chemical and optical properties of the resulting beads were investigated with electron microscopy, dynamic light scattering, optical spectroscopy, and fluorescence microscopy. Particle size distribution, fluorescence quantum yield of the encapsulated QDs, and QD leaking stability were used as measures for bead quality. The derived optimized bead encoding procedure enables the reproducible preparation of bright PS microbeads encoded with organic dyes as well as with CdSe/CdS-QDs. Although these beads show a reduced photoluminescence quantum yield compared to the initially very strongly luminescent QDs, with values of about 35%, their photoluminescence quantum yield is nevertheless still moderate.
KW - Polymerization
KW - Quantum dots
KW - Microbeads
KW - Fluorescence
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553430
DO - https://doi.org/10.1038/s41598-022-16065-x
SN - 2045-2322
VL - 12
SP - 1
EP - 16
PB - Nature Publishing Group
CY - London
AN - OPUS4-55343
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Scholtz, Lena
T1 - Luminescent Polymer Microbeads – Synthesis & Applications
N2 - Differently sized, luminescent polymer beads encoded with QDs were prepared with a simple, optimized polymerization procedure. The optical
properties of the resulting particles were studied to ensure sufficient fluorescence. In addition, possible future applications were identified.
T2 - Future WiNS: New Energies for a Sustainable World
CY - Berlin, Germany
DA - 07.12.2022
KW - Polymerization
KW - Quantum dots
KW - Fluorescence
KW - Luminescence
PY - 2022
AN - OPUS4-56560
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Wegner, Karl David
T1 - Luminescent Quantum dots – the next-generation nano light bulbs
N2 - Fluorescent semiconductor nanocrystals, also known as quantum dots (QDs), enabled many advancements in biotechnology, photovoltaics, photocatalysis, quantum computing and display devices. The high versatility of this nanomaterial is based on their unique size-tunable photoluminescence properties, which can be adjusted from the visible to the near-infrared range. In contrast to other nanomaterials, QDs made the transition from a laboratory curiosity to the utilization in commercial products, like the QLED television screen or in smartphone displays. The best investigated QDs are composed of heavy metals like cadmium or lead, which is not the best choice in terms of toxicity and environmental pollution. A more promising material is Indium Phosphide (InP), which is also currently used by Samsung, Sony and co. in the QLED displays.
In this contribution, I would like to give you a sneak peek behind the curtains of nanomaterial synthesis and show how this material is produced, how to stabilize their structural properties, and assess their toxicity in environmentally relevant conditions. Furthermore, I would like to present a synthesis method to accomplish the last open challenge in display technology of a blue luminescent LED based on QDs by introducing a new element to the InP QDs.
T2 - The Berlin Postdoc Day
CY - Berlin, Germany
DA - 03.11.2022
KW - InP
KW - Quantum dots
KW - Fluorescence
KW - Aging
KW - Doping
KW - Nanomaterial
KW - Cytotoxicity
PY - 2022
AN - OPUS4-56194
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Weidner, Steffen
T1 - MALDI-ToF mass spectrometry for the characterization of biobased polymers suitable for depollution
N2 - In this work, bio-based polymers were synthesized and designed as polymers phases for adsorption of a variety of pollutants from aqueous solutions. The obtained adsorption results showed that the integration of bio-sourced synthons generate attractive hydrophilicity, and wettability of the resulting adsorbent phase. Such polymers phases enable stronger interactions with the organic and inorganic pollutants in water.
A wide variety of different bio-based polymers structures (e. g. poly(ethersulfones, poly(etherphosphines or poly(etherpyridines) with different functional groups were successfully designed in order to adapt chemical structure to different pollutants type and matrice nature.
In order to characterize and to determine the correlation between polymer structures and nature of interaction with pollutants, different analytical technics (NMR, GPC, ATG, DSC, Mass spectrometry) were successfully used. Amongst them, MALDI TOF mass spectrometry plays a superior role since this technique enables the simultaneous determination of the polymer structure, polymer end groups and molecular weight.
This work focusses on the characterization of synthesized polymers. The chemical structure of the repeating unit, the nature of the end groups, as well as the molecular weight, which are all important for the specific interactions of the polymer with the pollutants were clearly determined and suggestions to improve these interactions by changing the synthetic pathway could be given.
T2 - 12. Journees maghreb-europe. Matériaux et Applications aux Dispositifs et Capteurs
CY - Monastir, Tunisia
DA - 08.11.2022
KW - MALDI TOF MS
KW - Biobased polymers
KW - Depollution
PY - 2022
AN - OPUS4-56237
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
ED - Hahn, Oliver
ED - Danielewski, A.
ED - Nöller, Renate
ED - Doil, Thorsten
T1 - Manuscripta americana - Den Azteken auf der Spur - Eine Ausstellung im Kulturwerk der Staatsbibliothek zu Berlin - 07. Dezember 2022 bis 26. Februar 2023
N2 - Die Publikation befasst sich mit einer einzigartigen Sammlung mexikanischer und südamerikanischer Handschriften, die zu Beginn des 19. Jahrhunderts ins Leben gerufen wurde, als Alexander von Humboldt der Königlichen Bibliothek zu Berlin Fragmente indigener mexikanischer Bilderhandschriften aus dem 16. Jahrhundert schenkte. Sie sind heute auch unter der Bezeichnung Humboldt-Fragmente bekannt und stellen den bedeutendsten Teil der Sammlung dar, die im Laufe der Zeit durch den Ankauf verschiedener Arten von Handschriften aus Mittelamerika, vorwiegend in indigenen Sprachen und lateinischer Schrift, erweitert wurde.
In den zwei Jahren von April 2017 bis März 2019 verfolgten die Staatsbibliothek zu Berlin – Preußischer Kulturbesitz (SBB-PK) und die Bundesanstalt für Materialforschung und -prüfung (BAM) ein gemeinsames, von der Deutschen Forschungsgemeinschaft (DFG) großzügig gefördertes wissenschaftliches Projekt: Materialanalysen und kulturgeschichtliche Untersuchungen mexikanischer Handschriften aus der Kolonialzeit in Berlin und Krakau.
Die Hauptziele des Projekts bestanden darin, die Provenienz der Manuscripta americana zu ermitteln und, da sie einen hohen Grad an Fragmentierung aufweisen, festzustellen, wie sie untereinander und mit Objekten außerhalb der Sammlung in Beziehung stehen. Zu diesem Zweck wurden ethno-kulturhistorische und naturwissenschaftliche Methoden kombiniert. Dank einer guten Zusammenarbeit mit der Jagiellonen-Bibliothek konnten wir die Manuscripta americana sowohl in Berlin als auch in Krakau sehen und studieren und sie wissenschaftlich vermessen.
T2 - Manuscripta americana - Den Azteken auf der Spur - Eine Ausstellung im Kulturwerk der Staatsbibliothek zu Berlin
CY - Berlin, Germany
DA - 07.12.2022
KW - Archäometrie
KW - Zerstörungsfreie Prüfung
KW - Manuskripte
KW - Amate
PY - 2022
SN - 2567-1251
N1 - Es gibt parallele Sprachausgaben (englisch und spanisch), Links befinden sich im Feld zugehöriger Identifikator - There are parallel language editions (English and Spanish), links are in the field related identifier
VL - 4
SP - 1
EP - 120
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-56729
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
ED - Hahn, Oliver
ED - Danielewski, A.
ED - Nöller, Renate
ED - Doil, Thorsten
T1 - Manuscripta americana - Fragments of the Aztec legacy - An exhibition at Kulturwerk in the Staatsbibliothek zu Berlin - December 07, 2022 until February 26, 2023
N2 - This publication, which accompanies the exhibition Manuscripta americana - On the traces of the Aztecs, concerns a unique collection of Mexican and South American manuscripts. The collection was established at the beginning of the 19th century, when Alexander von Humboldt donated fragments of 16th century indigenous Mexican pictorial manuscripts to the Royal Library in Berlin. Today these are also known as the Humboldt fragments and represent the most significant part of a collection that was augmented over the years by the purchase of various types of Mesoamerican manuscripts, mainly in indigenous languages with Latin script.
During the two year period from April 2017 to March 2019, the Berlin State Library (SBB - SPK) and the Bundesanstalt für Materialforschung und -prüfung (BAM) carried out a joint scientific project funded by the Deutsche Forschungsgemeinschaft (DFG) entitled "Material-analytical and cultural-historical examinations of colonial-period manuscripts from Mexico in Berlin and Cracow."
The main objectives of the project were to determine the provenance of the Manuscripta americana and, since they exhibit a high degree of fragmentation, to examine how they are related to each other and to objects outside the collection. The investigation combined ethnocultural-historical and materials science methods of analysis. Thanks to the constructive partnership with the Jagiellonian Library, we were able to see and study the Manuscripta americana in both Kraków and Berlin and to carry out scientific measurements on them.
T2 - Manuscripta Americana - Fragments of the Aztec Legacy - An Exhibition at Kulturwerk in the Staatsbibliothek zu Berlin
CY - Berlin, Germany
DA - 07.12.2022
KW - Amate
KW - Archaeometry
KW - Manuscripts
KW - Nondestructive testing
PY - 2022
SN - 2567-1251
N1 - Es gibt parallele Sprachausgaben (deutsch und spanisch), Links befinden sich im Feld zugehöriger Identifikator - There are parallel language editions (German and Spanish), links are in the field related identifier
VL - 4
SP - 1
EP - 120
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-62419
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
ED - Hahn, Oliver
ED - Danielewski, A.
ED - Nöller, Renate
ED - Doil, Thorsten
T1 - Manuscripta americana - Tras las huellas de los aztecas - La exposición en la Kulturwerk en la Staatsbibliothek zu Berlin - 07 diciembre 2022 hasta el 26 de febrero de 2023
T1 - Manuscripta americana - Den Azteken auf der Spur - Eine Ausstellung im Kulturwerk der Staatsbibliothek zu Berlin - 07. Dezember 2022 bis 26. Februar 2023
N2 - Esta publicación, que acompaña a la exposición Manuscripta americana. Tras las huellas de los aztecas, se ocupa de una colección excepcional de manuscritos mexicanos y sudamericanos. La colección se inició cuando, a principios del siglo XIX, Alexander von Humboldt donó a la Biblioteca Real de Berlín varios fragmentos de manuscritos pictográficos indígenas del siglo XVI procedentes del actual México. Estos documentos, conocidos habitualmente como Fragmentos Humboldt, representan la parte más notable de la colección, que con el tiempo se fue ampliando a través de la adquisición de diferentes manuscritos mesoamericanos, principalmente escritos en lenguas indígenas con caracteres latinos.
Entre abril de 2017 y marzo de 2019, la Staatsbibliothek zu Berlin - PK (SBB) y el Bundesanstalt für Materialforschung und -prüfung (BAM) llevaron a cabo un proyecto científico conjunto, financiado generosamente por la Deutsche Forschungsgemeinschaft (DFG) con el nombre de Análisis material y estudios histórico-culturales de manuscritos coloniales mexicanos en Berlín y Cracovia.
Los principales objetivos del proyecto fueron determinar la procedencia de los manuscritos americanos y, dado que presentan un alto grado de fragmentación, establecer sus relaciones internas y las que establecen con otros objetos ajenos a la colección. Para ello, se combinaron métodos de análisis de corte etnográfico, cultural e histórico con otros propios de las ciencias naturales. Gracias a la buena cooperación con la Bibliotheka Jagiellońska tuvimos acceso tanto a los Manuscripta americana de Berlín como a los de Cracovia, pudiendo proceder a su examen exhaustivo y realizar exámenes científicos de alta precisión.
N2 - Die Publikation befasst sich mit einer einzigartigen Sammlung mexikanischer und südamerikanischer Handschriften, die zu Beginn des 19. Jahrhunderts ins Leben gerufen wurde, als Alexander von Humboldt der Königlichen Bibliothek zu Berlin Fragmente indigener mexikanischer Bilderhandschriften aus dem 16. Jahrhundert schenkte. Sie sind heute auch unter der Bezeichnung Humboldt-Fragmente bekannt und stellen den bedeutendsten Teil der Sammlung dar, die im Laufe der Zeit durch den Ankauf verschiedener Arten von Handschriften aus Mittelamerika, vorwiegend in indigenen Sprachen und lateinischer Schrift, erweitert wurde.
In den zwei Jahren von April 2017 bis März 2019 verfolgten die Staatsbibliothek zu Berlin – Preußischer Kulturbesitz (SBB-PK) und die Bundesanstalt für Materialforschung und -prüfung (BAM) ein gemeinsames, von der Deutschen Forschungsgemeinschaft (DFG) großzügig gefördertes wissenschaftliches Projekt: Materialanalysen und kulturgeschichtliche Untersuchungen mexikanischer Handschriften aus der Kolonialzeit in Berlin und Krakau.
Die Hauptziele des Projekts bestanden darin, die Provenienz der Manuscripta americana zu ermitteln und, da sie einen hohen Grad an Fragmentierung aufweisen, festzustellen, wie sie untereinander und mit Objekten außerhalb der Sammlung in Beziehung stehen. Zu diesem Zweck wurden ethno-kulturhistorische und naturwissenschaftliche Methoden kombiniert. Dank einer guten Zusammenarbeit mit der Jagiellonen-Bibliothek konnten wir die Manuscripta americana sowohl in Berlin als auch in Krakau sehen und studieren und sie wissenschaftlich vermessen.
T2 - Manuscripta americana - Tras las huellas de los aztecas - La exposición en la Kulturwerk en la Staatsbibliothek zu Berlin
CY - Berlin, Germany
DA - 07.12.2022
KW - Amate
KW - Arqueometria
KW - Manuscrito
KW - Pruebas no destructivas
PY - 2022
SN - 2567-1251
N1 - Es gibt parallele Sprachausgaben (deutsch und englisch), Links befinden sich im Feld zugehöriger Identifikator - There are parallel language editions (German and English), links are in the field related identifier
VL - 4
SP - 1
EP - 120
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-62427
LA - spa
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, Cui
A1 - Kitzmann, W.R.
A1 - Weigert, Florian
A1 - Förster, Ch.
A1 - Wang, X.
A1 - Heintze, K.
A1 - Resch-Genger, Ute
T1 - Matrix Effects on Photoluminescence and Oxygen Sensitivity of a Molecular Ruby
N2 - The molecular ruby analogue [Cr(ddpd)2]3+ (ddpd=N,N’-dimethyl-N,N’-dipyridine-2-ylpyridine-2,6-diamine) exhibits near infrared (NIR) emission with a high photoluminescence (PL) quantum yield ΦPL of 11 % and a lifetime of 898 μs in deaerated water at room temperature. While ligand-based control of the photophysical properties has received much attention, influences of the counter anions and microenvironment are still underexplored. In this study, the luminescence properties of the molecular ruby were systematically examined for the counter anions Cl−, Br−, [BF4]−, [PF6]−, [BPh4]−, and [BArF24]− in acetonitrile (MeCN) solution, in crystals, and embedded into polystyrene nanoparticles (PSNP). Stern-Volmer analyses of the oxygen quenching studies in the intensity and lifetime domain showed the highest oxygen sensitivity of the complexes with the counter anions of [BF4]− and [BArF24]−, which also revealed the longest luminescence lifetimes. Embedding [Cr(ddpd)2][PF6]3 in PSNPs and shielding with poly(vinyl alcohol) yields a strongly NIR-emissive oxygen-insensitive material with a record ΦPL of 15.2 % under ambient conditions.
KW - Fluorescence
KW - Sensor
KW - Oxygen
KW - Quantum yield
KW - Quality assurance
KW - Complex
KW - Cr(III)
KW - Lifetime
KW - Ligand
KW - Solid state
KW - X-Ray analysis
KW - Structure-property relationship
KW - Nano
KW - Polymer
KW - Particle
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546057
DO - https://doi.org/10.1002/cptc.202100296
SN - 2367-0932
VL - 6
IS - 6
SP - 1
EP - 9
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54605
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Wachtendorf, Volker
T1 - Maßgeschneiderte künstliche Bewitterungstests zur Untersuchung der alterungsbedingten Freisetzung von Produkten in die Umwelt
N2 - Genormte künstliche Bewitterungstests sind häufig nicht spezifisch für die Anwendungssituation oder das Material. Das macht die Entwicklung spezifischer Tests erforderlich. Für deren Entwicklung müssen Maximalparameter der Anwendungssituation bekannt sein, womit dann der künstliche Test formuliert wird und dessen Bedingungen werden dann solange optimiert, bis die Korrelation der Effekte von natürlichem und künstlichem Test ausreichend ist.
Für Untersuchungen der Freisetzung kann der verbleibende Rest in der Probe und/oder die freigesetzte Menge in Luft, Boden, Wasser bestimmt werden.
Im ersten Beispiel der Witterungswirkung wurde die Freisetzung von Kohlenstoff-Nanoröhrchen (CNT) aus Polymer-Kompositen untersucht (unter Verwendung von empfindlich-nachweisbarer radioaktiver 14C-Markierung für einzelne CNT-Partikel), in einem zweiten die Freisetzung von anorganischen und organischen Bestandteilen aus elastomeren Bestandteilen von Sportböden (Bahnen und Kunstrasen) in Wasser.
T2 - SKZ-Tagung: Bewitterung van Kunststoffen
CY - Würzburg, Germany
DA - 06.07.2022
KW - Künstliche Bewitterung
KW - UV
KW - Degradation
KW - Freisetzung
KW - CNT
KW - Carbo-Nanotubes
KW - Composite
KW - Nano-Partikel
KW - 14C-Markierung
KW - Sportböden
KW - Kunstrasen
KW - Grundwasser
PY - 2022
AN - OPUS4-55219
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Procop, Mathias
A1 - Terborg, R.
T1 - Measurement and calculation of x-ray production efficiencies for copper, zirconium, and tungsten
N2 - Electron probe microanalysis (EPMA) is based on physical relations between measured X-ray intensities of characteristic lines and their Xray production efficiency, which depends on the specimen composition. The quality of the analysis results relies on how realistically the physical relations describe the generation and emission of X-rays. Special experiments are necessary to measure X-ray production efficiencies. A challenge in these experiments is the determination of the detection efficiency of the spectrometer as a function of the photon energy. An energy-dispersive spectrometer was used in this work, for which the efficiency was determined at metrological synchrotron beamlines with an accuracy of ±2%. X-ray production efficiencies for the L series and the Kα series of copper and zirconium and for the M and L series of tungsten were determined at energies up to 30 keV in a scanning electron microscope. These experimental values were compared with calculated X-ray production efficiencies using physical relations and material constants applied in EPMA. The objective of the comparison is the further improvement of EPMA algorithms as well as extending the available database for X-ray production efficiencies. Experimental data for the X-ray production efficiency are also useful for the assessment of spectrum simulation software.
KW - Copper
KW - Electron probe microanalysis
KW - Tungsten
KW - X-ray production efficiency
KW - Zirconium
PY - 2022
DO - https://doi.org/10.1017/S1431927622012351
VL - 28
IS - 6
SP - 1865
EP - 1877
PB - Oxford University Press
CY - Oxford
AN - OPUS4-55711
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Simon, Franz-Georg
A1 - Kalbe, Ute
T1 - Measurement of the Environmental Impact of Materials
N2 - This Special Issue, ‘Measurement of the Environmental Impact of Materials’, is focused on the impact that materials have on the environmental compartments of soil, water and air. Leaching and emission processes, including underlying mechanisms, are a recurring topic in most published articles in the present Special Issue. Contributions have come from three continents and numerous countries (USA, Germany, France, Latvia, Poland, Russia, Japan, Korea and Thailand) indicating the global dimension of the subject.
KW - Leaching
KW - Recycling
KW - Nano-materials
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545099
DO - https://doi.org/10.3390/ma15062208
SN - 1996-1944
VL - 15
IS - 6
SP - 1
EP - 3
PB - MDPI
CY - Basel
AN - OPUS4-54509
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kosareva, E.
A1 - Gainutdinov, R.
A1 - Michalchuk, Adam
A1 - Ananyev, I.
A1 - Muravyev, N.
T1 - Mechanical Stimulation of Energetic Materials at the Nanoscale
N2 - The initiation of energetic materials by mechanical stimuli is a critical stage of their functioning, but remains poorly understood. Using atomic force microscopy (AFM) we explore the microscopic initiation behavior of four prototypical energetic materials: 3,4-dinitropyrazole, 𝜖-CL-20, 𝛼-PETN and picric acid. Along with the various chemical structures, these energetic compounds cover a range of application types: a promising melt-cast explosive, the most powerful energetic compound in use, a widespread primary explosive, and a well-established nitroaromatic explosive from the early development of energetics. For the softest materials (picric acid and 3,4-dinitropyrazole), the surfaces were found to behave dynamically, quickly rearranging in response to mechanical deformation. The pit created by nanoscale friction stimulation on the surface of 3,4-dinitropyrazole doubled in volume upon aging for half an hour. Over the same time frame, a similar pit on picric acid surface increased in volume by more than seven-fold. Remarkably, increased humidity was found to reduce the rate of surface rearrangement, potentially offering an origin for the desensitization of energetic materials when wetted. Finally, we identify an inverse correlation between the surface dynamics and mechanical sensitivity of our test energetic compounds. This strongly suggests that surface dynamics influence a material’s ability to dissipate excess energy, acting as a buffer towards mechanical initiation.
KW - Energetic materials
KW - Mechanical Properties
KW - Mechanical Sensitivity
PY - 2022
DO - https://doi.org/10.1039/D2CP00832G
VL - 24
IS - 15
SP - 8890
EP - 8900
PB - Royal Society of Chemistry
AN - OPUS4-54562
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bloi, L. M.
A1 - Hippauf, F.
A1 - Boenke, T.
A1 - Rauche, M.
A1 - Paasch, S.
A1 - Schutjajew, K.
A1 - Pampel, Jonas
A1 - Schwotzer, F.
A1 - Dörfler, S.
A1 - Althues, H.
A1 - Oschatz, M.
A1 - Brunner, E.
A1 - Kaskel, S.
T1 - Mechanistic insights into the reversible lithium storage in an open porous carbon via metal cluster formation in all solid-state batteries
N2 - Porous carbons are promising anode materials for next generation lithium batteries due to their large lithium storage capacities. However, their highsloping capacity during lithiation and delithiation as well as capacity fading due to intense formation of solid electrolyte interphase (SEI) limit their gravimetric and volumetric energy densities. Herein we compare a microporous carbide-derived carbon material (MPC) as promising future anode for all solid-state batteries with a commercial high-performance hard carbon anode. The MPC obtains high and reversible lithiation capacities of 1000 mAh g−1carbon in half-cells exhibiting an extended plateau region near 0 V vs. Li/Li+ preferable for full-cell application. The well-defined microporosity of the MPC with a specific surface area of >1500 m2 g−1 combines well with the argyrodite-type electrolyte (Li6PS5Cl) suppressing extensive SEI formation to deliver high coulombic efficiencies. Preliminary full-cell measurements vs. nickel-rich NMC-cathodes (LiNi0.9Co0.05Mn0.05O2) provide a considerably improved average potential of 3.76 V leading to a projected energy density as high as 449 Wh kg−1 and reversible cycling for more than 60 cycles. 7Li Nuclear Magnetic Resonance spectroscopy was combined with ex-situ Small Angle X-ray Scattering to elucidate the storage mechanism of lithium inside the carbon matrix. The formation of extended quasi-metallic lithium clusters after electrochemical lithiation was revealed.
KW - All solid-state battery
KW - Microporous carbon
KW - Lithium battery
KW - Anode
PY - 2022
DO - https://doi.org/10.1016/j.carbon.2021.11.061
SN - 0008-6223
VL - 188
SP - 325
EP - 335
PB - Elsevier Ltd.
AN - OPUS4-54079
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rautenberg, Max
A1 - Gernhard, M.
A1 - Radnik, Jörg
A1 - Witt, Julia
A1 - Roth, C.
A1 - Emmerling, Franziska
T1 - Mechanochemical synthesis of fluorine-containing Co-doped zeolitic imidazolate frameworks for producing electrocatalysts
N2 - Catalysts derived from pyrolysis of metal organic frameworks (MOFs) are promising candidates to replace expensive and scarce platinum-based electrocatalysts commonly used in polymer electrolyte membrane fuel cells. MOFs contain ordered connections between metal centers and organic ligands. They can be pyrolyzed into metal- and nitrogen-doped carbons, which show electrocatalytic activity toward the oxygen reduction reaction (ORR). Furthermore, metal-free heteroatom-doped carbons, such as N-F-Cs, are known for being active as well. Thus, a carbon material with Co-N-F doping could possibly be even more promising as ORR electrocatalyst. Herein, we report the mechanochemical synthesis of two polymorphs of a zeolitic imidazole framework, Co-doped zinc 2-trifluoromethyl-1H-imidazolate (Zn0.9Co0.1(CF3-Im)2). Time-resolved in situ X-ray diffraction studies of the mechanochemical formation revealed a direct conversion of starting materials to the products. Both polymorphs of Zn0.9Co0.1(CF3-Im)2 were pyrolyzed, yielding Co-N-F containing carbons, which are active toward electrochemical ORR.
KW - Mechanochemistry
KW - Metal-organic-frameworks
KW - Nobel-metal free electrocatalysis
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546833
DO - https://doi.org/10.3389/fchem.2022.840758
SN - 2296-2646
VL - 10
IS - 840758
SP - 1
EP - 13
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-54683
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rautenberg, Max
A1 - Bhattacharya, Biswajit
A1 - Das, Chayanika
A1 - Emmerling, Franziska
T1 - Mechanochemical Synthesis of Phosphonate-Based Proton Conducting Metal-Organic Frameworks
N2 - Water-stable metal−organic frameworks (MOFs) with proton-conducting behavior have attracted great attention as promising materials for proton-exchange membrane fuel cells. Herein, we report the mechanochemical gram-scale synthesis of three new mixed-ligand phosphonate-based MOFs, {Co(H2PhDPA)(4,4′-bipy)H2O)·2H2O}n (BAM-1), {Fe(H2PhDPA)(4,4′-bipy) (H2O)·2H2O}n (BAM-2), and {Cu(H2PhDPA)(dpe)2(H2O)2·2H2O}n (BAM-3) [where H2PhDPA = phenylene diphosphonate, 4,4′-bipy = 4,4′-bipyridine, and dpe = 1,2-di(4-pyridyl)ethylene]. Single-crystal X-ray diffraction measurements revealed that BAM-1 and BAM-2 are isostructural and possess a three-dimensional (3D) network structure comprising one-dimensional (1D) channels filled with guest water molecules. Instead, BAM-3 displays a 1D network structure extended into a 3D supramolecular structure through hydrogenbonding and π−π interactions. In all three structures, guest water molecules are interconnected with the uncoordinated acidic hydroxyl groups of the phosphonate moieties and coordinated water molecules by means of extended hydrogen-bonding interactions. BAM-1 and BAM-2 showed a gradual increase in proton conductivity with increasing temperature and reached 4.9 × 10−5 and 4.4 × 10−5 S cm−1 at 90 °C and 98% relative humidity (RH). The highest proton conductivity recorded for BAM-3 was 1.4 × 10−5 S cm−1 at 50 °C and 98% RH. Upon further heating, BAM-3 undergoes dehydration followed by a phase transition to another crystalline form which largely affects its performance. All compounds exhibited a proton hopping (Grotthuss model) mechanism, as suggested by their low activation energy.
KW - Mechanochemistry
KW - Metal-organic-frameworks
KW - Proton conductivity
PY - 2022
DO - https://doi.org/10.1021/acs.inorgchem.2c01023
VL - 61
SP - 10801
EP - 10809
PB - ACS Publications
AN - OPUS4-55448
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lin, R.
A1 - Li, X.
A1 - Krajnc, A.
A1 - Li, Z.
A1 - Li, M.
A1 - Wang, W.
A1 - Zhuang, L.
A1 - Smart, S.
A1 - Zhu, Z.
A1 - Appadoo, D.
A1 - Harmer, J. R.
A1 - Wang, Z.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Beyer, S.
A1 - Wang, L.
A1 - Mali, G.
A1 - Bennett, T. D.
A1 - Chen, V.
A1 - Hou, J.
T1 - Mechanochemically Synthesised Flexible Electrodes Based on Bimetallic Metal–Organic Framework Glasses for the Oxygen Evolution Reaction
N2 - The melting behaviour of metal–organic frameworks (MOFs) has aroused significant research interest in the areas of materials science, condensed matter physics and chemical engineering. This work first introduces a novel method to fabricate a bimetallic MOF glass, through meltquenching of the cobalt-based zeolitic imidazolate Framework (ZIF) [ZIF-62(Co)] with an adsorbed ferric coordination complex. The high-temperature chemically reactive ZIF-62-(Co) liquid facilitates the formation of coordinative bonds between Fe and imidazolate ligands, incorporating Fe nodes into the framework after quenching. The resultant Co–Fe bimetallic MOF glass therefore shows a significantly enhanced oxygen evolution reaction performance. The novel bimetallic MOF glass, when combined with the facile and scalable mechanochemical synthesis technique for both discrete powders and surface coatings on flexible substrates, enables significant opportunities for catalytic device Assembly
KW - Electrodes
KW - MOF
KW - OER
KW - XANES
KW - XAS
KW - Bimetallic frameworks
PY - 2022
DO - https://doi.org/10.1002/anie.202112880
VL - 61
IS - 4
SP - e202112880
PB - Wiley
AN - OPUS4-54018
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Darvishi Kamachali, Reza
T1 - Melting upon Coalescence of Solid Nanoparticles
N2 - The large surface-to-volume ratio of nanoparticles is understood to be the source of many interesting phenomena. The melting temperature of nanoparticles is shown to dramatically reduce compared to bulk material. Yet, at temperatures below this reduced melting point, a liquid-like atomic arrangement on the surface of nanoparticles is still anticipated to influence its properties. To understand such surface effects, here, we study the coalescence of Au nanoparticles of various sizes using molecular dynamics simulations. Analysis of the potential energy and Lindemann index distribution across the nanoparticles reveals that high-energy, high-mobility surface atoms can enable the coalescence of nanoparticles at temperatures much lower than their corresponding melting point. The smaller the nanoparticles, the larger the difference between their melting and coalescence temperatures. For small enough particles and/or elevated enough temperatures, we found that the coalescence leads to a melting transition of the two nominally solid nanoparticles, here discussed in relation to the heat released due to the surface reduction upon the coalescence and the size dependence of latent heat. Such discontinuous melting transitions can lead to abrupt changes in the properties of nanoparticles, important for their applications at intermediate temperatures.
KW - Nanoparticles
KW - Molecular Dynamics
KW - Surface-induced Melting
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552183
DO - https://doi.org/10.3390/solids3020025
VL - 3
IS - 2
SP - 361
EP - 373
PB - MDPI
AN - OPUS4-55218
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - von Werder, Julia
T1 - metabuilding labs: OITB presentation and how BAM an NBK can contribute
N2 - The aim of the project metabuilding labs to establish an EU wide network of testing facilities and innovation services for new building envelope technologies & products is presented. Further the envisaged contribution of BAM and the private Frech research center NOBATEK is explained.
T2 - ENBRI/BBRI workshop “Hygrothermal testing – a necessity to guarantee durable buildings”
CY - Brussels, Belgium
DA - 21.09.2022
KW - Building envelope
KW - Building facade
KW - Test bench
KW - Pilot building
KW - Open innovation testbed
PY - 2022
AN - OPUS4-56389
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Fellinger, Tim-Patrick
T1 - Metal chloride activation revisited: a sol-gel process to functional carbons
N2 - Porous carbon materials are known for their applicability in important areas such as sorption, catalysis and electrochemistry (e.g. fuel cell catalysts, supercapacitor or battery electrodes). It was shown that nitrogen doped carbons (NDCs) act as an inexpensive and highly active non-metal catalyst in the oxygen reduction reaction (ORR), with the potential to reach performances of practical need one day. A key strategy towards improvement for this aim comprises the generation of advantageous porosity, which typically means high surface area and mass transport pores as well as the control over the chemistry of catalytically active sites. My group is developing novel sol-gel type strategies that are using molten salts or molten acids as unconventional reaction medium for the porogenesis in doped carbons, thereby revisiting classic activation techniques.[1,2] Carbon materials with extra high surface area of ~2800 m2 g-1 and pore volumes, up to four times as high as in commercial activated carbons, are obtained.[3] It turns out that the meso- and macrostructure is generated by means of phase separation rather than leaching reactions. However, chemical reactions between the carbon precursor and the melt are also involved. The salt cations Mg2+ and Zn2+ act as template ions, which results in metal coordination sites, embedded into the carbon structure.[4,5] The imprinted structure may be utilized as catalytically active site by performing ion-exchange reactions. The novel preparation strategy towards highly active electrocatalysts will be presented for Mg and Zn and further discussed for lighter elements.
T2 - Carbon Chemistry and Materials Conference 2022
CY - Rome, Italy
DA - 10.10.2024
KW - Activated carbon
KW - Salt templating
PY - 2022
AN - OPUS4-61936
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Binder, F.
A1 - Bircher, B.
A1 - Laquai, René
A1 - Küng, A.
A1 - Bellon, Carsten
A1 - Meli, F.
A1 - Deresch, A.
A1 - Ulrich Neuschaefer-Rube, U.
A1 - Hausotte, T.
T1 - Methodologies for model parameterization of virtual CTs for measurement uncertainty estimation
N2 - X-ray computed tomography (XCT) is a fast-growing technology for dimensional measurements in industrial applications. However, traceable and efficient methods to determine measurement uncertainties are not available. Guidelines like the VDI/VDE 2630 Part 2.1 suggest at least 20 repetitions of a specific measurement task, which is not feasible for industrial standards. Simulation-based approaches to determine task specific measurement uncertainties are promising, but require closely adjusted model parameters and an integration of error sources like geometrical deviations during a measurement. Unfortunately, the development of an automated process to parameterize and integrate geometrical deviations into XCT models is still an open issue. In this work, the whole processing chain of dimensional XCT measurements is taken into account with focus on the issues and requirements to determine suitable parameters of geometrical deviations. Starting off with baseline simulations of different XCT systems, two approaches are investigated to determine and integrate geometrical deviations of reference measurements. The first approach tries to iteratively estimate geometric deviation parameter values to match the characteristics of the missing error sources. The second approach estimates those values based on radiographs of a known calibrated reference object. In contrast to prior work both approaches only use a condensed set of parameters to map geometric deviations. In case of the iterative approach, some major issues regarding unhandled directional dependencies have been identified and discussed. Whereas the radiographic method resulted in task specific expanded measurements uncertainties below one micrometre even for bi-directional features, which is a step closer towards a true digital twin for uncertainty estimations in dimensional XCT.
KW - Geometrical deviation
KW - X-ray computed tomography
KW - Uncertainty estimation
KW - Virtual CT
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553263
DO - https://doi.org/10.1088/1361-6501/ac7b6a
VL - 33
IS - 10
SP - 1
EP - 15
PB - IOP Publishing
CY - Bristol, UK
AN - OPUS4-55326
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Tchipilov, Teodor
A1 - Raysyan, Anna
A1 - Weller, Michael G.
T1 - Methods for the quantification of particle-bound protein – Application to reagents for lateral-flow immunoassays (LFIA)
N2 - Protein immobilization for the functionalization of particles is used in various applications, including biosensors, lateral-flow immunoassays (LFIA), bead-based assays, and others. Common methods for the quantification of bound protein are measuring protein in the supernatant before and after coating and calculating the difference. This popular approach has the potential for a significant overestimation of the amount of immobilized protein since layers not directly bound to the surface (soft protein corona) are usually lost during washing and handling. Only the layer directly bound to the surface (hard corona) can be used in subsequent assays. A simplified amino acid analysis method based on acidic hydrolysis and RP-HPLC-FLD of tyrosine and phenylalanine (aromatic amino acid analysis, AAAA) is proposed to directly quantify protein bound to the surface of gold nano- and latex microparticles. The results are compared with indirect methods such as colorimetric protein assays, such as Bradford, bicinchoninic acid (BCA), as well as AAAA of the supernatant. For both particle types, these indirect quantification techniques show a protein overestimation of up to 1700% compared to the direct AAAA measurements. In addition, protein coating on latex particles was performed both passively through adsorption and covalently through EDC/sulfo-NHS chemistry. Our results showed no difference between the immobilization methodologies. This finding suggests that usual protein determination methods are no unambiguous proof of a covalent conjugation on particles or beads.
KW - Soft protein corona
KW - Hard protein corona
KW - Gold particles
KW - Nanoparticles
KW - Mikroparticles
KW - Antibody
KW - Bioconjugation
KW - Protein quantification
KW - Supernatant
KW - Sodium chloride method
KW - Covalent conjugation
KW - Latex particles
KW - Lateral flow immunoassays
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545365
DO - https://doi.org/10.20944/preprints202203.0332.v1
SP - 1
EP - 8
PB - MDPI
CY - Basel
AN - OPUS4-54536
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
ED - Bruno, Giovanni
T1 - Micro Non-Destructive Testing and Evaluation
N2 - What is meant by ‘Micro Non-Destructive Testing and Evaluation’? This was the central subject of debate in this Special Issue.
At present, sub-millimeter-size components or even assemblies are pervading the industrial and scientific world. Classic examples are electronic devices and watches (as well as parts thereof), but recent examples encompass additively manufactured lattice structures, stents, or other microparts. Moreover, most assemblies contain micro-components. Testing such components or their miniaturized parts would fit well within the topic of micro non-destructive testing and evaluation.
In all cases, performance and integrity testing, quality control, and dimensional tolerances need to be measured at the sub-millimeter level (ideally with a spatial resolution of about a micron); most of the time, such features and components are embedded in much larger assemblies, which also need to be taken into account. The solution to this dilemma (i.e. measuring large parts with high resolution) depends on the part and on the problem under consideration.
Another possible definition of micro non-destructive testing and evaluation can relate to the characterization of micro-features (e.g., the microstructure) in much larger specimens, such as damage in concrete cores or porosity in additively manufactured components. A further aspect is the use of microscopic probes to evaluate macroscopic properties. This is the case, for instance but not at all exclusively, in the use of diffraction techniques to determine macroscopic stress.
The splits between testing and characterization at the micro-level (or of micro parts) from one side and handling of macroscopic assemblies on the other represent a great challenge for many fields of materials characterization. On top of that, including the use of microscopic methods to test integrity would add a further level of complexity.
Imaging, mechanical testing, non-destructive testing, measurement of properties, structural health monitoring, and dimensional metrology all need to be re-defined if we want to cope with the multi-faceted topic of micro non-destructive testing and evaluation.
The challenge has already been accepted by the scientific and engineering communities for a while but is still far from being universally tackled. This Special Issue yields an interesting answer to the questions posed above. It presents the progress made and the different aspects of the challenge as well as at indicates the paths for the future of NDT&E.
KW - Neutron Diffraction
KW - Ultrasound
KW - Eddy Currents
KW - X-ray Computed Tomography
KW - Mechanical Properties
KW - Residual Stress
KW - Defects
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570321
SN - 978-3-0365-6180-6
DO - https://doi.org/10.3390/books978-3-0365-6180-6
SN - 1996-1944
SP - 1
EP - 304
PB - MDPI
CY - Basel
AN - OPUS4-57032
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ciornii, Dmitri
T1 - Micro- and Nanoplastics: from physico-chemical properties to reference products
N2 - In this presentation we demonstrate the importance of physico-chemical properties (pc) of micro- and nanoplastic particles (MNPs). These properties determine interaction between MNPs and cells or living organisms. To perform accurate experiments for acquiring pc information it is essential to develop well-characterized and understood plastic reference materials. Such reference materials can be used in interlaboratory comparisons (ILCs). BAM is organizing under VAMAS two ILCs, on micro- and nanoplastics to obtain reliable results and methodologies for pc characterization of MNPs. By gaining profound knowledge on pc properties it becomes possible to estimate the impact of MNPs on the humans and environment and therefore to translate the knowledge to the level of regulation.
T2 - CUSP early-stage researchers meeting
CY - Online meeting
DA - 08.11.2022
KW - Micro- and nanoplastics
KW - Plastic reference materials
KW - Interlaboratory Comparisons
PY - 2022
AN - OPUS4-56330
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kittner, Maria
A1 - Kerndorff, A.
A1 - Ricking, M.
A1 - Bednarz, M.
A1 - Obermaier, N.
A1 - Lukas, M.
A1 - Asenova, M.
A1 - Bordós, G.
A1 - Eisentraut, Paul
A1 - Hohenblum, P.
A1 - Hudcova, H.
A1 - Humer, F.
A1 - István, T. G.
A1 - Kirchner, M.
A1 - Marushevska, O.
A1 - Nemejcová, D.
A1 - Oswald, P.
A1 - Paunovic, M.
A1 - Sengl, M.
A1 - Slobodnik, J.
A1 - Spanowsky, K.
A1 - Tudorache, M.
A1 - Wagensonner, H.
A1 - Liska, I.
A1 - Braun, U.
A1 - Bannick, C. G.
T1 - Microplastics in the Danube River Basin: A First Comprehensive Screening with a Harmonized Analytical Approach
N2 - In this study, carried out within the Joint Danube Survey 4, a comprehensive microplastic screening in the water column within a large European river basin from its source to estuary, including major tributaries, was realized. The objective was to develop principles of a systematic and practicable microplastic monitoring strategy using sedimentation boxes for collection of suspended particulate matter followed by its subsequent analysis using thermal extraction desorption-gas chromatography/mass spectrometry. In total, 18 sampling sites in the Danube River Basin were investigated. The obtained suspended particulate matter samples were subdivided into the fractions of >100 μm and <100 μm and subsequently analyzed for microplastic mass contents. The results showed that microplastics were detected in all samples, with polyethylene being the predominant polymer with maximum contents of 22.24 μg/mg, 3.23 μg/mg for polystyrene, 1.03 μg/mg for styrene-butadiene-rubber, and 0.45 μg/mg for polypropylene. Further, polymers such as different sorts of polyester, polyacrylates, polylactide, and natural rubber were not detected or below the detection limit. Additional investigations on possible interference of polyethylene signals by algae-derived fatty acids were assessed. In the context of targeted monitoring, repeated measurements provide more certainty in the interpretation of the results for the individual sites. Nevertheless, it can be stated that the chosen approach using an integrative sampling and determination of total plastic content proved to be successful.
KW - Thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS), monitoring
KW - Microplastics
KW - River
KW - Suspended particulate matter (SPM)
KW - Sedimentation box (SB)
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551444
DO - https://doi.org/10.1021/acsestwater.1c00439
VL - 2
IS - 7
SP - 1174
EP - 1181
PB - ACS Publications
AN - OPUS4-55144
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Saloga, Patrick E. J.
A1 - Rybak, Tina
A1 - Thünemann, Andreas
T1 - Microwave-Assisted Synthesis of ZnO Nanoparticles: Phase Transfer to Water
N2 - Herein, a simple one-pot procedure is reported to obtain aqueous zinc oxide (ZnO) nanoparticle dispersions from ZnO nanoparticles dispersed in cyclohexane. In the process, polyoxyethylene (20) sorbitan monooleate (polysorbate 80, Tween 80) functions as a phase transfer agent and colloidal stabilizer. The particles grow in a defined manner during the transfer, presumably via coalescence. The final particle radii are tuneable in the range from 2.3 ± 0.1 nm to 5.7 ± 0.1 nm depending on the incubation time of the dispersion at 90 °C. Small-angle X-ray scattering is employed to determine the particle radius distributions before and after phase transfer. The larger ZnO particle radii are associated with a redshift of the optical bandgap and luminescence emission, as expected for semiconductor nanoparticles. The particles presented here exhibit a relative size distribution width of 20%, rendering them attractive for applications in, e.g., biology or catalysis. The latter application is demonstrated at the photocatalytic degradation of methylene blue dye.
KW - SAXS
KW - Small-angle X-ray scattering
KW - nanoparticle
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551502
DO - https://doi.org/10.1002/adem.202101276
VL - 24
IS - 6
SP - 1
EP - 7
PB - Wiley
AN - OPUS4-55150
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rizzardi, Q.
A1 - McElfresh, C.
A1 - Sparks, G.
A1 - Stauffer, D.
A1 - Marian, J.
A1 - Maaß, Robert
T1 - Mild-to-wild plastic transition is governed by athermal screw dislocation slip in bcc Nb
N2 - Plastic deformation in crystals is mediated by the motion of line defects known as dislocations.
For decades, dislocation activity has been treated as a homogeneous, smooth continuous process. However, it is now recognized that plasticity can be determined by longrange correlated and intermittent collective dislocation processes, known as avalanches. Here we demonstrate in body-centered cubic Nb how the long-range and scale-free dynamics at room temperature are progressively quenched out with decreasing temperature, eventually revealing intermittency with a characteristic length scale that approaches the Burgers Vector itself. Plasticity is shown to be bimodal across the studied temperature regime, with conventional thermally-activated smooth plastic flow (‘mild’) coexisting with sporadic Bursts (‘wild’) controlled by athermal screw dislocation activity, thereby violating the classical Notion of temperature-dependent screw dislocation motion at low temperatures. An abrupt increase of the athermal avalanche component is identified at the critical temperature of the material.
Our results indicate that plasticity at any scale can be understood in terms of the coexistence of these mild and wild modes of deformation, which could help design better alloys by suppressing one of the two modes in desired temperature Windows.
KW - Plastic deformation
KW - Microplastic stress
KW - Intermittent microplasticity
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543927
DO - https://doi.org/10.1038/s41467-022-28477-4
VL - 13
IS - 1
SP - 1
EP - 9
PB - Nature
AN - OPUS4-54392
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Lohrer, Christian
T1 - Misuse of pyrotechnics - a hazard assessment
N2 - The contribution focuses on intentional misuse of pyrotechnic articles, which are for the EU-market CE-marked and tested according to an intended use as declared by the manufacturer. Specific properties of the articles and associated hazards in view of the intended use and - in comparison - the illegal use are presented. Moreover, the basic concepts of the conformity assessment procedures and selected standard requirements for the articles concerned are described.
T2 - Security of Explosives pan-European Specialists Network — EXERTER, Virtual Conference - Year 4, topic: “Criminal use of explosives”
CY - Online meeting
DA - 06.04.2022
KW - Misuse
KW - Pyrotechnics
KW - Explosives
KW - Intended use
PY - 2022
AN - OPUS4-54614
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Dehkohneh, Abolfazl
T1 - Modelling biofilm formation and material colonisation for Knufia petricola
N2 - Rock-inhabiting black fungi are adapted to survive extreme stresses such as radiation and lack of water and are thus able to colonise arid material surfaces like solar panels and marble monuments. Black fungi can typically grow as one of two cell types: depending on the environmental conditions, they are able to form yeast-like cells or hyphal filaments. Knufia petricola is one member of the rock-inhabiting black fungi which functions as a model reference species. As there is no mathematical model for biofilm formation of RIF, we are going to develop a model for K. petricola which describes fungal growth on the level of individual cells adn biofilm formation.
T2 - Mini conference at University of Birmingham
CY - Birmingham, UK
DA - 05.10.2022
KW - Knufia petricola
KW - Rock-inhabiting black fungi
KW - individual-based modelling
PY - 2022
AN - OPUS4-56697
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Strangfeld, Christoph
T1 - Moisture distribution in amorphous porous materials
N2 - Mesopores dominate the material moisture and influence the gas diffusion through materials such as concrete or sandstone
T2 - Nano@bam Round Table Nano Materials
CY - Berlin, Germany
DA - 14.10.2022
KW - Physisorption
KW - Mesopores
KW - Amorphous materials
PY - 2022
AN - OPUS4-55998
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Frunza, L.
A1 - Zgura, I
A1 - Ganea, C. P.
A1 - Schönhals, Andreas
T1 - Molecular dynamics of alkyl benzoate liquid crystals in the bulk state and in the surface layer of their composites with oxide nanopowders
N2 - This paper presents the results concerning monotropic nematic liquid crystals 4-pentylphenyl 40-alkyl benzoate (5PnB) (n = 3 or 5 carbon atoms in the alkyl chain). Their mesophase properties were supported by images of the polarized optical microscopy. Molecular dynamics in the bulk samples or in the composites prepared with aerosil A380 was investigated by broadband dielectric spectroscopy in a large temperature range, appropriately chosen. Thermo gravimetric and infrared investigations were additionally performed. The data were compared with those of structurally related nematics like cyanophenyl pentyl benzoates, which have a cyan group instead of the pentyl chain. The dielectric spectra of the bulk 3P5B and 5P5B demonstrate a dielectric behavior with several relaxation processes as expected for nematic liquid crystals. The temperature dependence of the relaxation rates (and of the dielectric strength) seems to have two distinguished regimes. Thus, in the isotropic state, at higher temperatures the data obey the Vogel–Fulcher–Tammann law, whereas an Arrhenius law is fitted at lower temperature, in a close similarity to the behavior of a constrained dynamic glass transition. Samples with a high density of silica (larger than 7 g aerosil/1 g of 5PnB) were prepared to observe a thin layer adsorbed on the particle surface; it was estimated that almost each guest 5PnB molecule interacts with the aerosil surface. For the composites only one main relaxation process is observed at frequencies much lower than those for the corresponding bulk, which was assigned to the dynamics of the molecules in the surface layer. Infrared spectroscopy shows that these molecules interact with the surface by the ester carbonyl group leading to the monolayer self-assembly at liquid–solid interface. We note once more the importance of the functional unit(s) for the interaction with the hydroxyl groups on the aerosil surface.
KW - Liquid crystals
PY - 2022
DO - https://doi.org/10.1016/j.molliq.2022.119374
SN - 0167-7322
VL - 359
SP - 1
EP - 11
PB - Elsevier B.V.
AN - OPUS4-54867
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sternbaek, L.
A1 - Kimani, Martha Wamaitha
A1 - Gawlitza, Kornelia
A1 - Rurack, Knut
A1 - Janicke, B.
A1 - Alm, K.
A1 - Gjörloff-Wingren, A.
A1 - Eriksson, H.
T1 - Molecularly Imprinted Polymers Exhibit Low Cytotoxic and Inflammatory Properties in Macrophages In Vitro
N2 - Molecularly imprinted polymers (MIPs) against sialic acid (SA) have been developed as a detection tool to target cancer cells. Before proceeding to in vivo studies, a better knowledge of the overall effects of MIPs on the innate immune system is needed. The aim of this study thus was to exemplarily assess whether SA-MIPs lead to inflammatory and/or cytotoxic responses when administered to phagocytosing cells in the innate immune system. The response of monocytic/macrophage cell lines to two different reference particles, Alhydrogel and PLGA, was compared to their response to SA-MIPs. In vitro culture showed a cellular association of SA-MIPs and Alhydrogel, as analyzed by flow cytometry. The reference particle Alhydrogel induced secretion of IL-1b from the monocytic cell line THP-1, whereas almost no secretion was provoked for SA-MIPs. A reduced number of both THP-1 and RAW 264.7 cells were observed after incubation with SA-MIPs and this was not caused by cytotoxicity. Digital holographic cytometry showed that SA-MIP treatment affected cell division, with
much fewer cells dividing. Thus, the reduced number of cells after SA-MIP treatment was not linked to SA-MIPs cytotoxicity. In conclusion, SA-MIPs have a low degree of inflammatory properties, are not cytotoxic, and can be applicable for future in vivo studies.
KW - Molecularly imprinted polymers
KW - Digital holographic cytometry
KW - Cytotoxicity
KW - Proinflammatory cytokines
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552250
DO - https://doi.org/10.3390/app12126091
SN - 2076-3417
VL - 12
IS - 12
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-55225
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kromer, C.
A1 - Schwibbert, Karin
A1 - Gadicherla, A. K.
A1 - Thiele, Dorothea
A1 - Nirmalananthan-Budau, Nithiya
A1 - Laux, P.
A1 - Resch-Genger, Ute
A1 - Luch, A.
A1 - Tschiche, H. R.
T1 - Monitoring and imaging pH in biofilms utilizing a fluorescent polymeric nanosensor
N2 - Biofilms are ubiquitous in nature and in the man-made environment. Given their harmful effects on human health, an in-depth understanding of biofilms and the monitoring of their formation and growth are important. Particularly relevant for many metabolic processes and survival strategies of biofilms is their extracellular pH. However, most conventional techniques are not suited for minimally invasive pH measurements of living biofilms. Here, a fluorescent nanosensor is presented for ratiometric measurements of pH in biofilms in the range of pH 4.5–9.5 using confocal laser scanning microscopy. The nanosensor consists of biocompatible polystyrene nanoparticles loaded with pH-inert dye Nile Red and is surface functionalized with a pH-responsive fluorescein dye. Its performance was validated by fluorometrically monitoring the time-dependent changes in pH in E. coli biofilms after glucose inoculation at 37 °C and 4 °C. This revealed a temperature-dependent decrease in pH over a 4-h period caused by the acidifying glucose metabolism of E. coli. These studies demonstrate the applicability of this nanosensor to characterize the chemical microenvironment in biofilms with fluorescence methods.
KW - Dye
KW - Fluorescence
KW - Signal enhancement
KW - Sensor
KW - Quantum yield
KW - Synthesis
KW - Nanoparticle
KW - Nano
KW - Polymer
KW - Ph
KW - Biofilm
KW - MIC
KW - Corrosion
KW - Microorganism
KW - Bacteria
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550751
DO - https://doi.org/10.1038/s41598-022-13518-1
SN - 2045-2322
VL - 12
IS - 1
SP - 1
EP - 10
PB - Nature Publishing Group
CY - London
AN - OPUS4-55075
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dubey, A.
A1 - Hon Keat, C.
A1 - Shvartsman, V.
A1 - Yusenko, Kirill
A1 - Escobar, M.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Hagemann, U.
A1 - Kovalenko, S.
A1 - Stächler, J.
A1 - Lupascu, D.
T1 - Mono-, Di-, and Tri-valent Cation Doped BiFe0.95Mn0.05O3 Nanoparticles: Ferroelectric Photocatalysts
N2 - The ferroelectricity of multivalent co-doped Bismuth ferrite (BiFeO3; BFO) nanoparticles (NPs) is revealed and utilized for light photocatalysis exploiting their narrow electronic band gap. The photocatalytic activity of ferroelectric photocatalysts BiFe0.95Mn0.05O3 (BFM) NPs and mono-, di-, or tri-valent cations (Ag+, Ca2+, Dy3+; MDT) co-incorporated BFM NPs are studied under ultrasonication and in acidic conditions. We find that such doping enhances the photocatalytic activity of the ferroelectric NPs approximately three times. The correlation of the photocatalytic activity with structural, optical, and electrical properties of the doped NPs is established. The increase of spontaneous polarization by the mono- and tri-valent doping is one of the major factors in enhancing the photocatalytic performance along with other factors such as stronger light absorption in the visible range, low recombination rate of charge carriers and larger surface area of NPs. A-site doping of BFO NPs by divalent elements suppresses the polarization, whereas trivalent (Dy3+) and monovalent (Ag+) cations provide an increase of polarization. The depolarization field in these single domain NPs acts as a driving force to mitigate recombination of the photoinduced charge carriers.
KW - Piezoresponse
KW - Bismuth Ferrite
KW - Nanoparticles
KW - Photocatalysis
KW - Ferroelectric
KW - Polarization
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557230
DO - https://doi.org/10.1002/adfm.202207105
SN - 1616-301X
SP - 1
EP - 16
PB - Wiley
AN - OPUS4-55723
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radnik, Jörg
A1 - Hodoroaba, Vasile-Dan
T1 - Morpho-Chemical Characterisation of Me-TiO2 Nanoparticles for Enhanced Photocatalytical Activity
N2 - The conversion of solar energy into electricity and solar fuels is of crucial importance for a green and sustainable future. Water splitting using semiconductor photo-catalysts is considered a sustainable method to produce clean hydrogen (H2) fuel. Nevertheless, H2 photo-production efficiency remains still low, although extensive research works to understand better the mechanisms of the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are being carried out. In this respect, TiO2 is a key photoactive material, usually employed with a co-catalyst deposited onto the surface to enhance charge carriers’ separation and catalyze surface charge transfer reactions. The deposition of a co-catalyst on the TiO2 nanoparticle surface represents one successful way to enhance the activity of the photocatalyst through a modification of its surface and redox properties. In this context, high-resolution scanning electron microscopy coupled with elemental analysis by energy-dispersive X-ray spectroscopy (EDS) is fundamental for studying and understanding the effect of the nanoparticle morphology on the functional properties of shape-controlled TiO2 crystals (bipyramides, platelets, and elongated particles). Different types of metal-semiconductor combinations, TiO2 shapes and dopant metals (Ag, Pt, etc) and metal concentrations will be discussed.
T2 - ECASIA 2022
CY - Limerick, Ireland
DA - 29.05.2022
KW - Titania nanoparticles
KW - Photocatalysis
KW - Scanning electron microscopy
KW - Energy dispersive X-ray spectroscopy
PY - 2022
AN - OPUS4-54977
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ernst, O. C.
A1 - Böttcher, K.
A1 - Fischer, Daniel
A1 - Uebel, D.
A1 - Teubner, T.
A1 - Boeck, T.
T1 - Morphogenesis of liquid indium microdroplets on solid molybdenum surfaces during solidification at normal pressure and under vacuum conditions
N2 - Electrical and optical applications based on micro- and nanoparticles have specific demands on their interfacial properties. These properties are strongly related to atmospheric conditions to which the particles were exposed during their formation. In this study, metallic In microparticles are synthesized by solidification of In droplets on an amorphous Mo substrate at normal pressure and under vacuum conditions. The influence of ambient pressure on the interface and surface shape is investigated. While solidification at atmospheric pressure leads to collapsed particles with undisturbed contact to the substrate, low pressures result in smooth spherical particles but with cavities inside. Numerical simulations with COMSOL Multiphysics reveal different temperature profiles and heat flux in particles during solidification for both cases. This indicates different starting conditions of the solidification, which leads to the described phenomenon eventually. The investigation of the varying process conditions on the particle shape in combination with the calculated and measured temperature curves over time gives valuable insights into new approaches to synthesize micro- and nanoparticles with defined interfacial properties. Both ambient pressure and cooling rate provide well-controllable and reliable parameters for the realization of different interfacial shapes.
KW - Morphogenesis
KW - Indium
KW - Microdroplet
KW - Molybdenum
PY - 2022
DO - https://doi.org/10.1021/acs.langmuir.1c02744
SN - 0743-7463
SN - 1520-5827
VL - 38
IS - 2
SP - 762
EP - 768
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-54242
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hodoroaba, Vasile-Dan
T1 - Morphological Characterization and Chemical Identification of TiO2 Nanoparticles Doped with Ultrafine Metal Particles for Enhanced Photocatalytical Activity
N2 - Water splitting using semiconductor photo-catalysts is considered a sustainable method to produce clean hydrogen fuel. Nevertheless, H2 photo-production efficiency remains still low, although extensive research works to understand better the mechanisms of the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are being carried out. In this respect, TiO2 is a key photoactive material, usually employed with a co-catalyst deposited onto the surface to enhance charge carriers’ separation and catalyze surface charge transfer reactions. The deposition of a co-catalyst on the TiO2 nanoparticle surface represents one successful way to enhance the activity of the photocatalyst through a modification of its surface and redox properties. In this context, high-resolution scanning electron microscopy (SEM) coupled with elemental analysis by energy-dispersive X-ray spectroscopy (EDS) is fundamental for studying and understanding the effect of the nanoparticle morphology on the functional properties of shape-controlled TiO2 crystals (bipyramides, platelets, and elongated particles). Different types of metal-semiconductor combinations, TiO2 shapes and dopant metals (Ag, Pt, Au, Rh, Pd) and metal concentrations are discussed.
T2 - Microscopy and Microanalysis 2022
CY - Portland, OR, USA
DA - 31.07.2022
KW - Nanoparticles
KW - Me-TiO2
KW - Photocatalysis
KW - Morpho-chemical characterization
KW - Shape
KW - SEM/EDS
PY - 2022
AN - OPUS4-55541
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Srivastava, Priyanka
A1 - Tavernaro, Isabella
A1 - Genger, C.
A1 - Welker, P.
A1 - Huebner, Oskar
A1 - Resch-Genger, Ute
T1 - Multicolor Polystyrene Nanosensors for the Monitoring of Acidic, Neutral, and Basic pH Values and Cellular Uptake Studies
N2 - A first tricolor fluorescent pH nanosensor is presented, which was rationally designed from biocompatible carboxylated polystyrene nanoparticles and two analyte-responsive molecular fluorophores. Its fabrication involved particle staining with a blue-red-emissive dyad, consisting of a rhodamine moiety responsive to acidic pH values and a pH-inert quinoline fluorophore, followed by the covalent attachment of a fluorescein dye to the particle surface that signals neutral and basic pH values with a green fluorescence. These sensor particles change their fluorescence from blue to red and green, depending on the pH and excitation wavelength, and enable ratiometric pH measurements in the pH range of 3.0−9.0. The localization of the different sensor dyes in the particle core and at the particle surface was confirmed with fluorescence microscopy utilizing analogously prepared polystyrene microparticles. To show the application potential of these polystyrene-based multicolor sensor particles, fluorescence microscopy studies with a human A549 cell line were performed, which revealed the cellular uptake of the pH nanosensor and the differently colored emissions in different cell organelles, that is, compartments of the endosomal-lysosomal pathway. Our results demonstrate the underexplored potential of biocompatible polystyrene particles for multicolor and multianalyte sensing and bioimaging utilizing hydrophobic and/or hydrophilic stimuli-responsive luminophores.
KW - Microparticle
KW - Fluorescence
KW - Sensor
KW - pH
KW - Quantum yield
KW - Multiplexing
KW - Imaging
KW - Cell
KW - Quality assurance
KW - Nano
KW - Polymer
KW - Bioimaging
KW - Particle
KW - Application
PY - 2022
DO - https://doi.org/10.1021/acs.analchem.2c00944
VL - 94
IS - 27
SP - 9656
EP - 9664
PB - ACS
AN - OPUS4-55365
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CHAP
A1 - Schartel, Bernhard
ED - Morgan, A.B.
T1 - Multicomponent Flame Retardants
N2 - The important take home message of this chapter: When multicomponent flame retardant systems are applied to polymeric materials, it becomes possible to address multiple fire properties, increase efficiency, and minimize flame retardant use to maximize polymer property balance. Flame retardants are combined or used together with adjuvants or synergists; fibers and fillers make a crucial contribution to their fire properties. Multicomponent systems are discussed in their capacity as an overall powerful strategy for achieving and optimizing non-halogenated flame-retardant polymeric materials.
KW - Flame retardants
KW - Synergy
KW - Adjuvants
KW - Fillers
KW - Fibres
PY - 2022
SN - 978-1-119-75056-7
SP - 413
EP - 474
PB - Scrivener Publishing LLC
CY - Bevery
ET - 2nd Edition
AN - OPUS4-54426
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schartel, Bernhard
T1 - Multifunctional Elastomer/Graphene Nanocomposites
N2 - A few layer/multilayer graphene (MLG) with a specific surface area of BET=250 m2/g is proposed as an efficient multifunctional nanofiller for rubbers. The preparation method, i.e., ultrasonically-assisted solution mixing of master batches followed by two-roll milling, strongly influences the dispersion in the elastomeric matrix and is fundamental for the final properties. When homogenously dispersed, single stacks of only approximately 10 graphene sheets, with an aspect ratio of 34, work at low loadings, enabling the replacement of large amounts of carbon black (CB), an increase in efficiency, and a reduction in filler load. The appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing, gas barrier properties, electrical and thermal conductivity, as well as mechanical properties of different rubbers, as shown for chlorine-Isobutylene-Isoprene rubber (CIIR), nitrile-butadiene rubber (NBR), natural rubber (NR), and styrene-butadiene rubber (SBR). 3 phr of MLG tripled the Young’s modulus of CIIR, an effect equivalent to 20 phr of CB. The stronger interactions between MLG and NR or SBR also resulted in a reduction in the elongation at break by 20% and 50%, respectively, while the same parameter was hardly changed for CIIR/MLG and NBR/MLG. CIIR/MLG and NBR/MLG were stiffer but just as defomable than CIIR and NBR. The strong reinforcing effect of 3 phr MLG was confirmed by the increase of greater than 10 Shore A in hardness. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards flammability, the latter shown by the reduction in heat release rate in the cone calorimeter. We investigated MLG also as a synergist for reducing the aluminium trihydrate loading in flame retardant hydrogenated acrylonitrile-butadiene (HNBR), polybutadiene chloroprene (BR/CR), and chlorosulfonated polyethylene rubber(CSM). The higher the nanofiller concentration is, the greater the improvement in the properties. For instance, the permeability decreased by 30% at 3 phr of MLG, 50% at 5 phr and 60% at 10 phr, respectively. Moreover, the MLG nanocomposites improve stability of mechanical properties against the effects of weathering. In key experiments an increase in UV-absorption and a pronounced radical scavenging were proved as stabilizing mechanisms. In a nutshell, MLG is an efficient multifunctional nanofiller ready to be used for innovative rubber development.
T2 - 19th European Polymer Congress, EPF 2022
CY - Prague, Czech Republic
DA - 26.06.2022
KW - Graphene
KW - Nanocomposite
KW - Rubber
KW - Elastomer
PY - 2022
AN - OPUS4-55196
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Strommer, Bettina
A1 - Battig, Alexander
A1 - Frasca, Daniele
A1 - Schulze, Dietmar
A1 - Huth, Christian
A1 - Böhning, Martin
A1 - Schartel, Bernhard
T1 - Multifunctional Property Improvements by Combining Graphene and Conventional Fillers in Chlorosulfonated Polyethylene Rubber Composites
N2 - The incorporation of nanoparticles like multilayer graphene (MLG) into elastomeric composites boosts their technical performance, such as their mechanical behavior and electrical conductivity. Common filler types (carbon black (CB) and aluminum trihydroxide (ATH)) generally fulfill single, specific purposes and are often used in high loadings. CB typically reinforces rubber mechanically, while ATH increases flame retardancy. Small amounts of MLG reduce these high filler contents and maintain the multifunctional characteristics of rubber composites. In chlorosulfonated polyethylene (CSM) + ATH, an intrinsically flame-retardant rubber was designed to achieve the highest standards such as maximum average of heat emission (MARHE) <90 kW m−2, 3 phrMLG was substituted for 15 phr CB and/or 3 phr ATH via an industrially applicable processing approach. Replacing either CB or ATH resulted in a property profile that was multifunctionally improved in terms of features such as mechanical performance, reduced sorption, and flame retardance. MLG nanocomposites are reported to show promise as an industrially utilizable route to obtain multifunctional high-performance rubbers.
KW - Nanocomposites
KW - Rubber
KW - Multilayer graphene
KW - Flame retardancy
KW - Synergy
KW - Nanoparticles
KW - Elastomers
PY - 2022
DO - https://doi.org/10.1021/acsapm.1c01469
SN - 2637-6105
VL - 4
IS - 2
SP - 1021
EP - 1034
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-54330
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sachse, René
A1 - Hodoroaba, Vasile-Dan
A1 - Kraehnert, R.
A1 - Hertwig, Andreas
T1 - Multilevel effective material approximation for modeling ellipsometric measurements on complex porous thin films
N2 - Catalysts are important components in chemical processes because they lower the activation energy and thus determine the rate, efficiency and selectivity of a chemical reaction. This property plays an important role in many of today’s processes, including the electrochemical splitting of water. Due to the continuous development of catalyst materials, they are becoming more complex, which makes a reliable evaluation of physicochemical properties challenging even for modern analytical measurement techniques and industrial manufacturing.
We present a fast, vacuum-free and non-destructive analytical approach using multi-sample spectroscopic ellipsometry to determine relevant material parameters such as film thickness, porosity and composition of mesoporous IrOx–TiOy films. Mesoporous IrOx–TiOy films were deposited on Si wafers by sol–gel synthesis, varying the composition of the mixed oxide films between 0 and 100 wt%Ir. The ellipsometric modeling is based on an anisotropic Bruggeman effective medium approximation (a-BEMA) to determine the film thickness and volume fraction of the material and pores. The volume fraction of the material was again modeled using a Bruggeman EMA to determine the chemical composition of the materials. The ellipsometric fitting results were compared with complementary methods, such as scanning electron microscopy (SEM), electron probe microanalysis (EPMA) as well as environmental ellipsometric porosimetry (EEP).
KW - Electrochemical catalysts
KW - Mixed metal oxide
KW - Multi-sample analysis
KW - Spectroscopic ellipsometry
KW - Thin mesoporous films
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551026
DO - https://doi.org/10.1515/aot-2022-0007
SN - 2192-8584
SN - 2192-8576
VL - 11
IS - 3-4 (Topical issue: Ellipsometry)
SP - 137
EP - 147
PB - De Gruyter
CY - Berlin
AN - OPUS4-55102
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yildirim, Arda
A1 - Krause, Christina
A1 - Huber, P.
A1 - Schönhals, Andreas
T1 - Multiple glassy dynamics of a homologous series of triphenylene-based columnar liquid crystals – A study by broadband dielectric spectroscopy and advanced calorimetry
N2 - Hexakis(n-alkyloxy)triphenylene) (HATn) consisting of an aromatic triphenylene core and alkyl side chains are model discotic liquid crystal (DLC) systems forming a columnar mesophase. In the mesophase, the molecules of HATn self-assemble in columns, which has one-dimensional high charge carrier mobility along the columns. Here, a homologous series of HATn with different length of the alkyl chain (n = 5,6,8,10,12) is investigated using differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS) and advanced calorimetric techniques including fast scanning calorimetry (FSC) and specific heat spectroscopy (SHS). The investigation of the phase behavior was done utilizing DSC experiments and the influence of the alkyl chain length on the phase behavior was revealed. By the dielectric investigations probing the molecular mobility, a c-relaxation due to localized fluctuations as well as two glassy dynamics, the acore- and aalkyl-relaxation, were observed in the temperature range of the plastic crystalline phase. Moreover, the observed glassy dynamics were further studied employing advanced calorimetry. All observed relaxation processes are attributed to the possible specific molecular fluctuations and discussed in detail. From the results a transition at around n = 8 from a rigid constrained (n = 5,6) to a softer system (n = 10,12) was revealed with increasing alkyl chain length. A counterbalance of two competing effects of a polyethylene-like behavior of the alkyl chains in the intercolumnar domains and self-organized confinement is discussed in the context of a hindered glass transition.
KW - Discotic liquid crystals
KW - Broadband dielectric spectroscopy
KW - Advanced calorimetry
PY - 2022
DO - https://doi.org/10.1016/j.molliq.2022.119212
VL - 358
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-54721
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pinomaa, T.
A1 - Lindroos, M.
A1 - Jreidini, P.
A1 - Haapalehto, M.
A1 - Ammar, K.
A1 - Wang, Lei
A1 - Forest, S.
A1 - Provatas, N.
A1 - Laukkanen, A.
T1 - Multiscale analysis of crystalline defect formation in rapid solidification of pure aluminium and aluminium-copper alloys
N2 - Rapid solidification leads to unique microstructural features, where a less studied topic is the formation of various crystalline defects, including high dislocation densities, as well as gradients and splitting of the crystalline orientation. As these defects critically affect the material’s mechanical properties and performance features, it is important to understand the defect formation mechanisms, and how they depend on the solidification conditions and alloying. To illuminate the formation mechanisms of the rapid solidification induced crystalline defects, we conduct a multiscale modelling analysis consisting of bond-order potential-based molecular dynamics (MD), phase field crystal-based amplitude expansion simulations, and sequentially coupled phase field–crystal plasticity simulations. The resulting dislocation densities are quantified and compared to past experiments. The atomistic approaches (MD, PFC) can be used to calibrate continuum level crystal plasticity models, and the framework adds mechanistic insights arising from the multiscale analysis.
This article is part of the theme issue ‘Transport phenomena in complex systems (part 2)’.
KW - Rapid solidification
KW - Crystalline defects
KW - Molecular dynamics
KW - Phase field crystal
KW - Phase field method
KW - Crystal plasticity
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542156
DO - https://doi.org/10.1098/rsta.2020.0319
SN - 1364-503X
VL - 380
IS - 2217
SP - 1
EP - 20
PB - Royal Society
CY - London
AN - OPUS4-54215
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -