TY - JOUR
A1 - Altmann, Korinna
A1 - Braun, Ulrike
A1 - Bannick, C.-G.
A1 - Bednarz, M.
A1 - Herper, D.
A1 - Knefel, M.
T1 - TED-GC/MS: Schnelle Bestimmung von Mikroplastik-Massegehalten in verschiedenen Proben
N2 - Zur Ermittlung von Mikroplastik-Gehalten in verschiedenen Umweltmatrices ist ein schnelles Detektionsverfahren für die Routineanalytik notwendig. Ein solches Verfahren wird hier in Form der ThermoExtraktion/Desorption-GasChromatographie/ MassenSpektroskopie (TED-GC/MS) vorgestellt. Neben grundlegenden verfahrensspezifischen Erläuterungen zur Identifizierung und Quantifizierung von Mikroplastik werden auch exemplarische Beispiele aus unterschiedlichen Umweltkompartimenten und Produkten dargestellt. Neu vorgestellt wird ein neues Verfahren zur Analytik von Flaschenwasser. Dazu wurde ein Messfiltertiegel entwickelt, der besonders für Proben mit geringen Gehalten an abfiltrierbaren Stoffen geeignet ist
KW - Mikroplasik
KW - Mikroplastik-Analyse
KW - TED-GC/MS
KW - Thermoanalytische Verfahren
KW - Mikroplastik-Massengehalte
PY - 2020
VL - 2020
IS - 02
SP - 55
EP - 57
PB - Gesellschaft Deutscher Chemiker (GDCh)
CY - Frankfurt am Main
AN - OPUS4-50835
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Altmann, Korinna
T1 - BAM activities on microplastics
N2 - The presentation is about BAM's activities on the topic of microplastics. It describes what BAM has done in this field in recent years. On the one hand, TED-GC/MS is presented as an analytical method, on the other hand, currently available microplastic reference materials are presented.
T2 - JRC/BAM Workshop on ILC
CY - Online meeting
DA - 11.02.2021
KW - Microplastic
KW - TED-GC/MS
KW - Microplastic particles
KW - Reference materials
PY - 2021
AN - OPUS4-52120
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hallier, Dorothea C.
A1 - Smales, Glen Jacob
A1 - Seitz, H.
A1 - Hahn, Marc Benjamin
T1 - Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine
N2 - Small-angle X-ray scattering (SAXS) can be used for structural determination of biological macromolecules and polymers in their native states (e.g. liquid phase). This means that the structural changes of (bio-)polymers, such as proteins and DNA, can be monitored in situ to understand their sensitivity to changes in chemical environments. In an attempt to improve the reliability of such experiments, the reduction of radiation damage occurring from exposure to X-rays is required. One such method, is to use scavenger molecules to protect macromolecules against radicals produced during radiation exposure, such as reactive oxygen species (ROS). In this study we investigate the feasibility of applying the compatible solute, osmolyte and radiation protector Ectoine (THP(B)), as a scavenger molecule during SAXS measurements of the single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). In this case, we monitor the radiation induced changes of G5P during bio-SAXS measurments and the resulting microscopic energy-damage relation was determined from microdosimetric calculations by Monte-Carlo based particle scattering simulations with TOPAS/Geant4 and a custom target-model. This resulted in a median-lethal energy deposit of pure G5P at 4 mg mL−1 of E1/2 = 7 ± 5 eV, whereas a threefold increase of energy-deposit was needed under the presence of Ectoine to reach the same level of damage. This indicates that Ectoine increases the possible exposure time before radiation-damage to G5P is observed. Furthermore, the dominant type of damage shifted from aggregation in pure solutions towards a fragmentation for solutions containing Ectoine as a cosolute. These results are interpreted in terms of indirect radiation damage by reactive secondary species, as well as post-irradiation effects, related to preferential-exclusion of the cosolute from the protein surface. Hence, Ectoine is shown to provide a non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies.
KW - BioSAXS
KW - Bio-SAXS
KW - Cosolute
KW - Ectoine
KW - G5P
KW - GVP
KW - Radiation damage
KW - Radical Scavenger
KW - Single-stranded DNA-binding proteins
KW - X-ray scattering
KW - DNA
KW - ssDNA
KW - Protein
KW - SAXS
KW - Small-angle xray scattering
KW - McSAS3
KW - Dosimetry
KW - Microdosimetry
KW - Geant4
KW - Geant4-DNA
KW - Topas
KW - Topas-MC
KW - Monte-Carlo simulations
KW - Particle scattering simulations
KW - Topas-nBio
KW - OH Radical
KW - OH radical scavenger
KW - LEE
KW - Ionizing radiation damage
KW - Protein unfolding
KW - Ectoin
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568909
DO - https://doi.org/10.1039/d2cp05053f
SN - 1463-9076
SN - 1463-9084
VL - 25
IS - 7
SP - 5372
EP - 5382
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-56890
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kolmangadi, Mohamed Aejaz
A1 - Smales, Glen Jacob
A1 - ZhuoQing, Li
A1 - Yildirim, Arda
A1 - Wuckert, E.
A1 - Eutionnat, S.
A1 - Demel, F.
A1 - Huber, P
A1 - Lasachat, S.
A1 - Schönhals, Andreas
T1 - Side Chain Length-Dependent Dynamics and Conductivity in Self-Assembled Ion
N2 - We study the molecular mobility and electrical conductivity of a homologous series of linear shaped columnar ionic liquid crystals ILCn, (n = 8, 10, 12, 14, 16) using broadband dielectric spectroscopy (BDS), specific heat spectroscopy (SHS), and X-ray scattering. We aim to understand how the alkyl chain length influences the dynamics and electric conductivity in this system. Two dielectrically active relaxation modes are observed, the γ and the αcore process, that correspond to the localized fluctuations of the alkyl chains and cooperative motions of the aromatic core in the columns, respectively. Both the γ relaxation and the αcore process slow down with increasing alkyl chain length. SHS reveals one relaxation process, the αalkyl process that has a similar temperature dependence as that of the αcore process for ILC12, 14, and 16 but shifts to higher temperature for ILC8 and 10. For ILC12, 14, and 16, the absolute values of DC conductivity increase by 4 orders of magnitude at the transition from the plastic crystalline to hexagonal columnar phase. For ILC8 and 10, the DC conductivity behavior is similar to ionic liquids, where the conductivity is coupled with structural relaxation. Small-angle X-ray investigations reveal that both the intercolumnar distance and the disorder coherence length increase with alkyl chain length; conversely, the DC conductivity decreases monotonically.
KW - Ionic Liquid Crystals
PY - 2022
DO - https://doi.org/10.1021/acs.jpcc.2c03023
SN - 1932-7447
VL - 126
IS - 27
SP - 10995
EP - 11006
PB - ACS
AN - OPUS4-55194
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hallier, Dorothea C.
A1 - Smales, Glen Jacob
A1 - Seitz, H.
A1 - Hahn, Marc Benjamin
T1 - Inside back cover for the article "Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine"
N2 - Showcasing research from the Federal Institute for Material Research and Testing Berlin and Fraunhofer Institute for Celltherapy and Immunology Branch Bioanalytics and Bioprocesses Potsdam.
Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine.
We aimed to increase the possible undisturbed exposure time during bio-SAXS measurements of single-stranded DNA-binding proteins. Therefore small angle X-ray scattering was performed on Gene-V Protein (G5P/GVP), which is involved in DNA repair processes. To achieve this, irradiations were performed in presence and absence of the hydroxyl-radical scavenger and osmolyte Ectoine, which showed efficient radiation protection and prevented protein aggregation, thus allows for a non-disturbing way to improve structure-determination of biomolecules.
KW - Bio-SAXS
KW - BioSAXS
KW - Cosolute
KW - DNA
KW - Dosimetry
KW - Ectoin
KW - Ectoine
KW - G5P
KW - GVP
KW - Geant4
KW - Geant4-DNA
KW - Ionizing radiation damage
KW - LEE
KW - McSAS3
KW - Microdosimetry
KW - Monte-Carlo simulations
KW - OH Radical
KW - OH radical scavenger
KW - Protein
KW - Protein unfolding
KW - Radiation damage
KW - Radical Scavenger
KW - SAXS
KW - Single-stranded DNA-binding proteins
KW - Small-angle xray scattering
KW - Topas-MC
KW - Topas-nBio
KW - TopasMC
KW - X-ray scattering
KW - Particle scatterin simulations
KW - ssDNA
PY - 2023
DO - https://doi.org/10.1039/D3CP90056H
SN - 1463-9076
SN - 1463-9084
VL - 25
IS - 7
SP - 5889
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-57006
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kolmangadi, Mohamed Aejaz
T1 - Confinement induced Relaxations and phase behvaiour of nanoconfined Ionic Liquid Crystal
N2 - Ionic Liquid Crystals (ILCs) are materials that combine the properties of liquid crystals together with ionic conduction. It is known that liquid crystal mesophases in confinement exhibit anomalous dynamics and phase behavior. However, similar studies about factors that control the macroscopic properties of ILCs in confinement are limited. Here, Broadband Dielectric Spectroscopy (BDS), X-ray scattering, and calorimetry were applied to study the molecular dynamics, and phase behavior of a guanidinium based columnar ionic liquid crystal confined in self-ordered alumina oxide nanopores of pore sizes ranging from 180 nm down to 25 nm. It is aimed to understand how pore size and pore surface wettability (hydrophilic or hydrophobic) influence the molecular dynamics, and phase behavior for this system which are crucial for applications. The DSC measurements show: (i) the crystalline-liquid crystalline transition temperature has non-monotonic dependence on inverse pore diameter and (ii) the liquid crystalline-isotropic transition is completely suppressed for all the confined samples. This thermally suppressed transition was detected by BDS and X-ray scattering and is considered as a continuous phase transition instead of a discontinuous first order transition. BDS investigations reveal several relaxation processes for the bulk and confined scenarios. The relaxation modes are suppressed and become slower for the confined scenarios compared to the bulk. Possible molecular origins for these relaxation processes are discussed, and it is shown that the self-assembly of these ILCs is dynamic in nature.
T2 - CONFIT 2022
CY - Grenoble, France
DA - 10.10.2022
KW - Ionic Liquid crystals
KW - Nanoconfinement
KW - Conductivity
PY - 2022
AN - OPUS4-57339
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - Extending Bio-SAXS measurements of Single-Stranded DNA-Binding Proteins: Radiation Protection of G5P by Cosolutes
N2 - Small-angle X-ray scattering (SAXS) can be used for structural de- termination of biological macromolecules and polymers in their na- tive states. To improve the reliability of such experiments, the re- duction of radiation damage occurring from exposure to X-rays is needed.One method, is the use of scavenger molecules that protect macromolecules against radicals produced by radiation exposure.In this study we investigate the feasibility to apply the compatible solute, osmolyte and radiation protector Ectoine (THP(B)) as a scavenger throughout SAXS measurements of single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). Therefore we monitor the radiation induced changes of G5P during bio-SAXS. The resulting microscopic energy-damage relation was determined by particle scattering simu- lations with TOPAS/Geant4. The results are interpreted in terms of radical scavenging as well as post-irradiation effects, related to preferential-exclusion from the protein surface. Thus, Ectoine provides an non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies.
T2 - MultiChem Conference 2023
CY - Prague, Czech Republic
DA - 26.04.2023
KW - Bio-SAXS
KW - BioSAXS
KW - Compatible solute
KW - Cosolute
KW - DNA
KW - Dosimetry
KW - Ectoin
KW - Ectoine
KW - Ectoin
KW - G5P
KW - GVP
KW - Geant4
KW - Geant4-DNA
KW - Gene five protein
KW - Hydroxyectoine
KW - Ionizing radiation damage
KW - LEE
KW - McSAS3
KW - Microdosimetry
KW - Monte-Carlo simulations
KW - OH Radical
KW - OH radical scavenger
KW - Osmolyte
KW - Particle scattering simulations
KW - Protein
KW - Protein unfolding
KW - Proteins
KW - ROS
KW - Radiation damage
KW - Radical Scavenger
KW - Radical scavenger
KW - SAXS
KW - Single-stranded DNA-binding proteins
KW - Small-angle xray scattering
KW - Topas
KW - Topas-MC
KW - Topas-nBio
KW - X-ray scattering
KW - ssDNA
KW - Median lethal energy deposit
PY - 2023
AN - OPUS4-57407
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - BP150: Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine
N2 - Small-angle X-ray scattering (SAXS) can be used for structural determination of biological macromolecules and polymers in their native states (e.g. liquid phase). This means that the structural changes of (bio-)polymers, such as proteins and DNA, can be monitored in situ to understand their sensitivity to changes in chemical environments. In an attempt to improve the reliability of such experiments, the reduction of radiation damage occurring from exposure to X-rays is required. One such method, is to use scavenger molecules to protect macromolecules against radicals produced during radiation exposure, such as reactive oxygen species (ROS). In this study we investigate the feasibility of applying the compatible solute, osmolyte and radiation protector Ectoine (THP(B)), as a scavenger molecule during SAXS measurements of the single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). In this case, we monitor the radiation induced changes of G5P during bio-SAXS measurments and the resulting microscopic energy-damage relation was determined from microdosimetric calculations by Monte-Carlo based particle scattering simulations with TOPAS/Geant4 and a custom target-model. This resulted in a median-lethal energy deposit of pure G5P at 4 mg mL−1 of E1/2 = 7 ± 5 eV, whereas a threefold increase of energy-deposit was needed under the presence of Ectoine to reach the same level of damage. This indicates that Ectoine increases the possible exposure time before radiation-damage to G5P is observed. Furthermore, the dominant type of damage shifted from aggregation in pure solutions towards a fragmentation for solutions containing Ectoine as a cosolute. These results are interpreted in terms of indirect radiation damage by reactive secondary species, as well as post-irradiation effects, related to preferential-exclusion of the cosolute from the protein surface. Hence, Ectoine is shown to provide a non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies.
T2 - DPG Frühjahrstagung
CY - Dresden, Germany
DA - 26.03.2023
KW - Bio-SAXS
KW - BioSAXS
KW - Compatible solute
KW - Cosolute
KW - DNA
KW - Dosimetry
KW - Ectoin
KW - Ectoine
KW - G5P
KW - GVP
KW - Gene five protein
KW - Geant4
KW - Geant4-DNA
KW - Hydroxyectoine
KW - Ionizing radiation damage
KW - LEE
KW - McSAS3
KW - Microdosimetry
KW - Monte-Carlo simulations
KW - OH Radical
KW - OH radical scavenger
KW - Osmolyte
KW - Particle scattering simulations
KW - Protein
KW - Proteins
KW - Protein unfolding
KW - ROS
KW - Radiation damage
KW - Radical Scavenger
KW - SAXS
KW - Single-stranded DNA-binding proteins
KW - Small-angle xray scattering
KW - Topas
KW - Topas-MC
KW - Topas-nBio
KW - X-ray scattering
KW - Radical scavenger
KW - ssDNA
PY - 2023
AN - OPUS4-57254
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine
N2 - Small-angle X-ray scattering (SAXS) can be used for structural determination of biological macromolecules and polymers in their native states (e.g. liquid phase). This means that the structural changes of (bio-)polymers, such as proteins and DNA, can be monitored in situ to understand their sensitivity to changes in chemical environments. In an attempt to improve the reliability of such experiments, the reduction of radiation damage occurring from exposure to X-rays is required. One such method, is to use scavenger molecules to protect macromolecules against radicals produced during radiation exposure, such as reactive oxygen species (ROS). In this study we investigate the feasibility of applying the compatible solute, osmolyte and radiation protector Ectoine (THP(B)), as a scavenger molecule during SAXS measurements of the single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). In this case, we monitor the radiation induced changes of G5P during bio-SAXS measurments and the resulting microscopic energy-damage relation was determined from microdosimetric calculations by Monte-Carlo based particle scattering simulations with TOPAS/Geant4 and a custom target-model. This resulted in a median-lethal energy deposit of pure G5P at 4 mg mL−1 of E1/2 = 7 ± 5 eV, whereas a threefold increase of energy-deposit was needed under the presence of Ectoine to reach the same level of damage. This indicates that Ectoine increases the possible exposure time before radiation-damage to G5P is observed. Furthermore, the dominant type of damage shifted from aggregation in pure solutions towards a fragmentation for solutions containing Ectoine as a cosolute. These results are interpreted in terms of indirect radiation damage by reactive secondary species, as well as post-irradiation effects, related to preferential-exclusion of the cosolute from the protein surface. Hence, Ectoine is shown to provide a non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies.
T2 - #RSCposter 2023
CY - Online meeting
DA - 28.02.2023
KW - Bio-SAXS
KW - BioSAXS
KW - Cosolute
KW - DNA
KW - Dosimetry
KW - Ectoin
KW - Ectoine
KW - G5P
KW - GVP
KW - Geant4
KW - Geant4-DNA
KW - Ionizing radiation damage
KW - LEE
KW - McSAS3
KW - Microdosimetry
KW - Monte-Carlo simulations
KW - OH Radical
KW - OH radical scavenger
KW - Particle scattering simulations
KW - Protein
KW - Protein unfolding
KW - Radiation damage
KW - Radical Scavenger
KW - SAXS
KW - Single-stranded DNA-binding proteins
KW - Small-angle xray scattering
KW - Topas
KW - Topas-MC
KW - Topas-nBio
KW - X-ray scattering
KW - ssDNA
KW - Osmolyte
KW - Hydroxyectoine
KW - Compatible solute
KW - ROS
KW - radical scavenger
PY - 2023
UR - https://pubs.rsc.org/en/content/articlehtml/2023/cp/d2cp05053f
AN - OPUS4-57064
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Smales, Glen Jacob
A1 - Pauw, Brian Richard
A1 - Kolmangadi, Mohamed Aejaz
T1 - X-ray scattering datasets associated with the publication "Molecular Mobility of Polynorbornenes with Trimethylsiloxysilyl side groups: Influence of the Polymerization Mechanism"
N2 - X-ray scattering datasets for samples described in the 2022 publication "Molecular Mobility of Polynorbornenes with Trimethylsiloxysilyl side groups: Influence of the Polymerization Mechanism". This dataset includes both raw and processed X-ray scattering data for samples APTCN and MPTCN, alongside background measurements files (BKG).
KW - X-ray scattering
KW - SAXS
KW - MOUSE
KW - Membrane polymers
KW - Microporous polymers
PY - 2023
DO - https://doi.org/10.5281/zenodo.7621204
PB - Zenodo
CY - Geneva
AN - OPUS4-56972
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Smales, Glen Jacob
A1 - Pauw, Brian Richard
A1 - Kolmangadi, Mohamed Aejaz
T1 - X-ray scattering datasets associated with the publication "Side chain length dependent dynamics and conductivity in self assembled ion channels"
N2 - X-ray scattering datasets for samples described in the 2022 publication "Side chain length dependent dynamics and conductivity in self assembled ion channels". This dataset includes both raw and processed X-ray scattering data for samples ILC8, ILC10, ILC12, ILC14 and ILC16 alongside background measurement files (BKG).
KW - X-ray scattering
KW - SAXS
KW - MOUSE
KW - Columnar ionic liquid crystals
KW - Liquid crystals
PY - 2023
DO - https://doi.org/10.5281/zenodo.7621358
PB - Zenodo
CY - Geneva
AN - OPUS4-56973
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Smales, Glen Jacob
A1 - Hahn, Marc Benjamin
A1 - Hallier, Dorothea C.
A1 - Seitz, H.
T1 - X-ray scattering datasets and simulations associated with the publication "Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine"
N2 - This dataset contains the processed and analysed small-angle X-ray scattering data associated with all samples from the publications "Bio-SAXS of Single-Stranded DNA-Binding Proteins: Radiation Protection by the Compatible Solute Ectoine" (https://doi.org/10.1039/D2CP05053F).
Files associated with McSAS3 analyses are included, alongside the relevant SAXS data, with datasets labelled in accordance to the protein (G5P), its concentration (1, 2 or 4 mg/mL), and if Ectoine is present (Ect) or absent (Pure). PEPSIsaxs simulations of the GVP monomer (PDB structure: 1GV5 ) and dimer are also included.
TOPAS-bioSAXS-dosimetry extension for TOPAS-nBio based particle scattering simulations can be obtained from https://github.com/MarcBHahn/TOPAS-bioSAXS-dosimetry which is further described in https://doi.org/10.26272/opus4-55751.
This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under grant number 442240902 (HA 8528/2-1 and SE 2999/2-1). We acknowledge Diamond Light Source for time on Beamline B21 under Proposal SM29806. This work has been supported by iNEXT-Discovery, grant number 871037, funded by the Horizon 2020 program of the European Commission.
KW - SAXS
KW - Radiation protection
KW - Microdosimetry
KW - G5P
KW - Ectoine
KW - DNA-Binding protein
PY - 2023
DO - https://doi.org/10.5281/zenodo.7515394
PB - Zenodo
CY - Geneva
AN - OPUS4-56811
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Smales, Glen Jacob
A1 - Pauw, Brian Richard
A1 - Kolmangadi, Mohamed Aejaz
T1 - X-ray scattering datasets associated with the publication "Molecular Dynamics of Janus Polynorbornenes: Glass Transitions and Nanophase Separation"
N2 - X-ray scattering datasets for samples described in the 2020 publication "Molecular Dynamics of Janus Polynorbornenes: Glass Transitions and Nanophase Separation". This dataset includes both raw and processed X-ray scattering data for samples PTCHSiO-Pr, Bu, Hx, Oc and De, alongside background measurements files (BKG). This data was collected using the MOUSE project (instrument and methodology).
KW - X-ray scattering
KW - SAXS
KW - MOUSE
KW - Alkyls
KW - Polymers
PY - 2023
DO - https://doi.org/10.5281/zenodo.7614835
PB - Zenodo
CY - Geneva
AN - OPUS4-56971
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Agudo Jácome, Leonardo
T1 - In situ electron-beam 'melting' (sublimation) of gold microparticles in the SEM
N2 - Gold micro particles have been modified in the past using the high power density of a localized electron beam of acceleration voltages above 100 kV as an energy source to transform matter at the sub-micron scale in a transmission electron microscope uses. Here, the e-beam-induced transformation of precursor microparticles employing a low-energy e-beam with an acceleration voltage of 30 kV in a scanning electron microscope is implemented. Under these conditions, the technique can be classified between e-beam lithography, where the e-beam is used to mill holes in or grow some different material onto a substrate, and e-beam welding, where matter can be welded together when overcoming the melting phase. Modifying gold microparticles on an amorphous SiOx substrate reveals the dominant role of inelastic electron-matter interaction and subsequent localized heating for the observed melting and vaporization of the precursor microparticles under the electron beam. Monte-Carlo scattering simulations and thermodynamic modeling further support the findings.
T2 - IKZ International Fellowship Award & Summer School 2025 from May 5 to 7, 2025
CY - Berlin, Germany
DA - 05.05.2025
KW - Gold Nanoparticle
KW - Scanning Electron Microscopy
KW - In situ irradiation
KW - Thermodynamic modelling
KW - Heat Transfer
PY - 2025
AN - OPUS4-63256
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Robust Data Generation, Heuristics and Machine Learning for Materials Design
N2 - Despite significant progress, computational materials design still faces challenges, especially when simulating large systems needed to describe defects, interfaces, or amorphous states with the accuracy of density functional theory (DFT) or beyond.[1] To address these limitations, machine learning (ML) methods have become increasingly popular in recent years. In this talk, I will present how we’ve developed robust data generation strategies that support the creation and benchmarking of new ML models.[2] I’ll focus on methods for large-scale quantum-chemical bonding analysis and workflows for ML interatomic potentials. We’ve shown that quantum-chemical bonding properties can be used in ML models to predict phononic properties.[3] This enables us to validate several expected correlations— such as the link between bonding strength and force constants—on a large scale. Additionally, we’ve built an automated training framework for machine-learned interatomic potentials (autoplex).[4] Initial workflows include random structure searches, which are well-suited for general-purpose potentials, as well as workflows tailored to ML potentials with accurate phonon properties. While atomistic simulations are highly effective for certain material properties, others— like magnetism or synthesizability—remain difficult. In these cases, it’s promising to benchmark established ab initio methods against chemical heuristics or to develop new ML models based primarily on experimental data.[5,6]
T2 - SusML (Sustainable Machine Learning Workshop)
CY - Dresden, Germany
DA - 29.09.2025
KW - Materials Design
KW - Materials Acceleration Platforms
KW - Automation
KW - Workflows
KW - Machine Learned Interatomic Potentials
KW - Synthesizability
KW - Magnetism
PY - 2025
AN - OPUS4-64244
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Bustamante, Joana
A1 - Naik, Aakash
A1 - Ueltzen, Katharina
A1 - George, Janine
A1 - Ertural, Christina
T1 - Thermal Transport in Ag8TS6 (T= Si, Ge, Sn) Argyrodites: An Integrated Experimental, Quantum-Chemical, and Computational Modelling Study. DFT-part
N2 - This repository contains computational data supporting the manuscript titled *“Thermal Transport in Ag8TS6 (T= Si, Ge, Sn) Argyrodites: An Integrated Experimental, Quantum-Chemical, and Computational Modelling Study”* It includes raw data for vibrational properties, elastic properties and Bonding analysis.
KW - DFT
KW - QHA
KW - Lattice thermal conductivity
KW - Grüneisen parameter
PY - 2025
DO - https://doi.org/10.5281/zenodo.17399975
PB - Zenodo
CY - Geneva
AN - OPUS4-64671
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Bustamante, Joana
A1 - Naik, Aakash
A1 - Ueltzen, Katharina
A1 - Ertural, Christina
A1 - George, Janine
T1 - Thermal Transport in Ag8TS6 (T= Si, Ge, Sn) Argyrodites: An Integrated Experimental, Quantum-Chemical, and Computational Modelling Study.
N2 - This repository includes raw data for bonding analysis and lattice thermal conductivity using MLIP-MACE-MP03b, supporting the manuscript “Thermal Transport in Ag8TS6 (T= Si, Ge, Sn) Argyrodites: An Integrated Experimental, Quantum-Chemical, and Computational Modelling Study”
KW - DFT
KW - LOBSTER
KW - Lattice thermal conductivity
KW - MLIP
PY - 2025
DO - https://doi.org/10.5281/zenodo.17397456
PB - Zenodo
CY - Geneva
AN - OPUS4-64674
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Stawski, Tomasz
A1 - Miliute, Aiste
T1 - Structural Refinement of ZrV₂O₇ with Negative Thermal Expansion Using Pair Distribution Function Analysis
N2 - This repository contains Python scripts specifically developed for structural refinement of Zirconium Vanadate (ZrV₂O₇), a material known for its negative thermal expansion (NTE). The scripts implement Pair Distribution Function (PDF) analysis to refine crystal structures directly from experimental X-ray diffraction (XRD) data. The refinement workflow is built around the DiffPy-CMI library, enhanced with custom functionalities tailored for ZrV₂O₇ and similar oxide materials.
KW - Zirconium vandate
KW - Total scattering
KW - Pair distribution function
KW - Structure refinement
PY - 2025
DO - https://doi.org/10.5281/zenodo.15395752
PB - Zenodo
CY - Geneva
AN - OPUS4-64750
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Grandel, Jonas
T1 - Harmonic phonon dataset
N2 - Phonon Dataset calculated with DFT PBE and the foundational MACE-MP-0b3 model.
The data are presented and discussed in the following publication: https://doi.org/10.1063/5.0297006
KW - Phonon
KW - MACE
KW - DFT
PY - 2025
UR - https://github.com/ACEsuit/mace-foundations
PB - GitHub
CY - San Francisco, CA, USA
AN - OPUS4-64747
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Naik, Aakash Ashok
T1 - Linking quantum chemical bonding analysis descriptors to material property predictions
N2 - Examining the bonding between their constituent atoms in crystalline materials has played a vital role in understanding material properties. For instance, low thermal conductivity in materials is typically attributed to its anharmonicity, which has been reported to arise from strong antibonding interactions and local environment distortions. Employing an automated for bonding analysis that we developed, we have generated for ~13000 crystalline compounds such bonding analysis data. To create new descriptors from these data automatically, we extended our package LobsterPy. The curated descriptors span different types, including statistical representations of bonding characteristics for traditional ML algorithms (e.g., random forests), textual descriptions for large language models (LLMs), and structure graphs for graph neural networks (GNNs). These descriptors are then tested by employing them in several state-of-the-art ML algorithms and architectures to predict the mechanical, vibrational, and thermal properties of crystalline materials. Through this work, we are not only able to demonstrate how one can enhance the model’s predictive accuracy by incorporating quantum chemical bonding-based descriptors alongside typical composition and structure-based descriptors, but it also aids in uncovering relationships between bonding and materials properties on a larger scale, which was not possible before.
T2 - AI MSE 2025
CY - Bochum, Germany
DA - 18.11.2025
KW - Bonding analysis
KW - Machine learning
KW - Materials Descriptors
KW - Force constants
PY - 2025
AN - OPUS4-64791
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ueltzen, Katharina
T1 - Can simple exchange heuristics help us in predicting magnetic properties of solids?
N2 - Environmental and scarcity issues of common functional magnetic materials for, e.g., permanent magnets have intensified the search for rare-earth-free alternatives. This challenge is increasingly met by machine learning of magnetic properties of transition-metal compounds. Surprisingly, bond-angle-derived features were not found to be relevant for magnetic structure prediction in previous studies using DFT-computed labels. This contrasts with the Kanamori-Goodenough-Anderson (KGA) rules of superexchange, present in every magnetism textbook.
These semiempirical rules predict whether a nearest-neighbor magnetic interaction in insulators is FM or AFM based on the bond angle, orbital symmetry, and orbital occupancy. For some cases, the rules can be simplified further to only consider the bond angle of neighboring magnetic sites (KGA rules of thumb).
We review magnetism—bond angle trends within the MAGNDATA database, the largest collection of experimentally determined magnetic structures. Observed trends follow the KGA rules of thumb, and exceptions can be rationalized. In contrast, bond angles in a popular theoretical DFT database show very different trends and do not depend on the magnetic ordering.
Building on our analysis, we engineer heuristic-derived features for the machine learning of magnetic structures. We introduce a new, informative label for predicting magnetic structures that can be extended to magnetic sites and structures of arbitrary complexity. We show that features derived from the heuristic are of high importance for this machine learning task. Beyond this, our model enables the prediction of non-collinear magnetic structures.
T2 - AI MSE 2025
CY - Bochum, Germany
DA - 18.11.2025
KW - Magnetism
KW - Machine Learning
KW - Materials Design
KW - Chemically Complex Materials
PY - 2025
AN - OPUS4-64799
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zimmermann, Yoel
A1 - Bazgir, Adib
A1 - Al-Feghali, Alexander
A1 - Ansari, Mehrad
A1 - Bocarsly, Joshua
A1 - Brinson, L Catherine
A1 - Chiang, Yuan
A1 - Circi, Defne
A1 - Chiu, Min-Hsueh
A1 - Daelman, Nathan
A1 - Evans, Matthew
A1 - Gangan, Abhijeet S
A1 - George, Janine
A1 - Harb, Hassan
A1 - Khalighinejad, Ghazal
A1 - Takrim Khan, Sartaaj
A1 - Klawohn, Sascha
A1 - Lederbauer, Magdalena
A1 - Mahjoubi, Soroush
A1 - Mohr, Bernadette
A1 - Mohamad Moosavi, Seyed
A1 - Naik, Aakash Ashok
A1 - Ozhan, Aleyna Beste
A1 - Plessers, Dieter
A1 - Roy, Aritra
A1 - Schoeppach, Fabian
A1 - Schwaller, Philippe
A1 - Terboven, Carla
A1 - Ueltzen, Katharina
A1 - Wu, Yue
A1 - Zhu, Shang
A1 - Janssen, Jan
A1 - Li, Calvin
A1 - Foster, Ian
A1 - Blaiszik, Ben
T1 - 32 examples of LLM applications in materials science and chemistry: towards automation, assistants, agents, and accelerated scientific discovery
N2 - Large Language Models (LLMs) are reshaping many aspects of materials science and chemistry research, enabling advances in molecular property prediction, materials design, scientific automation, knowledge extraction, and more. Recent developments demonstrate that the latest class of models are able to integrate structured and unstructured data, assist in hypothesis generation, and streamline research workflows. To explore the frontier of LLM capabilities across the research lifecycle, we review applications of LLMs through 34 total projects developed during the second annual Large Language Model Hackathon for Applications in Materials Science and Chemistry, a global hybrid event. These projects spanned seven key research areas: (1) molecular and material property prediction, (2) molecular and material design, (3) automation and novel interfaces, (4) scientific communication and education, (5) research data management and automation, (6) hypothesis generation and evaluation, and (7) knowledge extraction and reasoning from the scientific literature. Collectively, these applications illustrate how LLMs serve as versatile predictive models, platforms for rapid prototyping of domain-specific tools, and much more. In particular, improvements in both open source and proprietary LLM performance through the addition of reasoning, additional training data, and new techniques have expanded effectiveness, particularly in low-data environments and interdisciplinary research. As LLMs continue to improve, their integration into scientific workflows presents both new opportunities and new challenges, requiring ongoing exploration, continued refinement, and further research to address reliability, interpretability, and reproducibility.
KW - Large Language Models
KW - Machine Learning
KW - Materials Design
KW - Bonding Analysis
KW - Phonons
KW - Thermal properties
PY - 2025
DO - https://doi.org/10.1088/2632-2153/ae011a
SN - 2632-2153
VL - 6
IS - 3
SP - 1
EP - 34
PB - IOP Publishing
AN - OPUS4-64019
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Namrata, Jaykhedkara
A1 - George, Janine
T1 - Atomistic interaction at the solid interface between Li6PS5Cl and Li metal
N2 - Solid-state batteries offer higher energy density and improved safety than conventional lithium-ion cells with flammable liquid electrolytes, [1] but poor interfacial compatibility at the solid-electrolyte (SE)|electrode interface, especially with lithium metal anodes, remains a major challenge. [2] To gain a deeper understanding of the structural and chemical factors governing the formation and growth of this interface, we selected Li6PS5Cl (SE) and Li metal anode as prototype materials. In this work, we begin by performing ab initio molecular dynamics accelerated by machine-learning potentials in VASP, to obtain lattice parameters and bulk moduli of the bulk Li6PS5Cl and Li metal phases, thereby quantifying lattice-mismatch strain, compressibility differences, and their thermal evolution. We then analyze the atomic structure and coordination environments at the Li6PS5Cl|Li interface, which is carefully constructed for the [100] orientation for both SE and Li, allowing the lowest possible strain (see Fig. 1). Dominant bonding motifs are identified using Crystal Orbital Hamilton Population [3] analysis via LOBSTER.[4] Radial distribution functions of the interface are compared with those of the respective bulk phases in the 200-400 K range to elucidate temperature-driven structural rearrangements. This combined analysis reveals how interfacial bonding evolves with temperature and provides critical insight into chemical and mechanical stability at the interface. Our findings offer a quantitative framework for correlating bulk properties with interfacial structure, thereby informing the design of more robust SEs and engineering strategies to improve interfacial compatibility.
T2 - 12th Workshop “Lithium-Sulfur Batteries”
CY - Dresden, Germany
DA - 17.11.2025
KW - Solid-state batteries
KW - Interface chemistry
KW - Machine learning-molecuar dynamics
PY - 2025
AN - OPUS4-64804
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Robust data generation, heuristics and machine learning for designing sustainable materials
N2 - Despite advances in computational materials design, simulating large systems—such as defects, interfaces, or amorphous states—with quantum-chemical accuracy remains a major challenge.[1] Machine learning (ML) methods are emerging as powerful tools to overcome these limitations, enabling scalable and accurate modeling beyond traditional quantum-chemical approaches.[2] They also open new avenues for discovering non-toxic, earth-abundant alternatives to existing materials and can be combined with self-driving labs. [3] There are nowadays robust data generation strategies that underpin the development and benchmarking of ML models. [4,5]atomate2 I will focus on such strategies for quantum-chemical bonding analysis and ML interatomic potentials in my talk. Quantum-chemical bonding descriptors can be effectively used in ML models to predict phononic properties. [6] ML interatomic potentials offer a powerful approach for predicting energies, forces, and stresses—but their performance hinges on high-quality training data. Our automated framework, autoplex, enables diverse and scalable training workflows, from random structure searches for general-purpose models to phonon-aware pipelines for high-accuracy predictions.[7] While quantum chemistry excels in many domains, properties like magnetism and synthesizability remain elusive. Here, heuristics or leveraging experimental data for ML offer promising alternatives.[8,9]
T2 - Advanced Materials Safety 2025
CY - Dresden, Germany
DA - 04.11.2025
KW - Nano Particles
KW - Machine Learning
KW - Automation
KW - Materials Design
KW - Sustainability
KW - Material Safety
PY - 2025
AN - OPUS4-64599
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Von der Computerchemie zur Materialinformatik
N2 - In dem Vortrag stelle ich meinen Lebenslauf von einem Chemiestudium bis hin zur Materialinformatik vor. Hierbei stelle ich unter anderem Computerchemie und Materialinformatik vor. Das beinhaltet Kurzeinführungen in die Quantenmechanik und das maschinelle Lernen.
T2 - Landesseminar Berlin Brandenburg der deutschen Auswahl für die Internationale Chemieolympiade (Schülerwettbewerb)
CY - Berlin, Germany
DA - 17.10.2025
KW - Materials Design
KW - Computational Chemistry
KW - Materials Acceleration Platforms
KW - Automation
KW - Machine Learning Potentials
KW - Outreach
PY - 2025
AN - OPUS4-64412
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cope, Elana J.
A1 - Bustamante, Joana
A1 - Johnson, Zöe M.
A1 - Lancaster, Alicia
A1 - Gurunathan, Ramya
A1 - George, Janine
A1 - Agne, Matthias T.
T1 - Heat capacity estimation of complex materials for energy technologies
N2 - The control of heat in energy materials is one of the greatest current engineering challenges. Accurate estimations of heat capacity are key in creating and using materials safely and efficiently. Current models for heat capacity are often limited due to crude estimations of the phonon density of states, which is a key component of the thermodynamic definition of heat capacity. Utilization of a more detailed phonon density of states, which can easily be obtained from machine-learned algorithms, combined with dilation and electronic contributions, yields heat capacity estimations that are 29% better than the widely utilized Debye model and are comparable to state-of-the-art quantum mechanical calculations. The framework and necessary tools for heat capacity estimations demonstrated herein can be built into more detailed models and analyses, such as high-throughput characterization, transport models, or other thermodynamic assessments. Consequently, the so-called vibrational + dilation + electronic (VDE) model of heat capacity developed in this work better enables the informed design of next-generation devices.
KW - Materials Design
KW - Heat Capacity
KW - Machine learning potentials
KW - Thermal Management
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-645711
DO - https://doi.org/10.1016/j.joule.2025.102054
SN - 2542-4351
VL - 9
IS - 8
SP - 1
EP - 12
PB - Elsevier Inc.
AN - OPUS4-64571
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Batatia, Ilyes
A1 - Benner, Philipp
A1 - Chiang, Yuan
A1 - Elena, Alin M.
A1 - Kovács, Dávid P.
A1 - Riebesell, Janosh
A1 - Advincula, Xavier R.
A1 - Asta, Mark
A1 - Avaylon, Matthew
A1 - Baldwin, William J.
A1 - Berger, Fabian
A1 - Bernstein, Noam
A1 - Bhowmik, Arghya
A1 - Bigi, Filippo
A1 - Blau, Samuel M.
A1 - Cărare, Vlad
A1 - Ceriotti, Michele
A1 - Chong, Sanggyu
A1 - Darby, James P.
A1 - De, Sandip
A1 - Della Pia, Flaviano
A1 - Deringer, Volker L.
A1 - Elijošius, Rokas
A1 - El-Machachi, Zakariya
A1 - Fako, Edvin
A1 - Falcioni, Fabio
A1 - Ferrari, Andrea C.
A1 - Gardner, John L. A.
A1 - Gawkowski, Mikołaj J.
A1 - Genreith-Schriever, Annalena
A1 - George, Janine
A1 - Goodall, Rhys E. A.
A1 - Grandel, Jonas
A1 - Grey, Clare P.
A1 - Grigorev, Petr
A1 - Han, Shuang
A1 - Handley, Will
A1 - Heenen, Hendrik H.
A1 - Hermansson, Kersti
A1 - Ho, Cheuk Hin
A1 - Hofmann, Stephan
A1 - Holm, Christian
A1 - Jaafar, Jad
A1 - Jakob, Konstantin S.
A1 - Jung, Hyunwook
A1 - Kapil, Venkat
A1 - Kaplan, Aaron D.
A1 - Karimitari, Nima
A1 - Naik, Aakash A.
A1 - Csányi, Gábor
T1 - A foundation model for atomistic materials chemistry
N2 - Atomistic simulations of matter, especially those that leverage first-principles (ab initio) electronic structure theory, provide a microscopic view of the world, underpinning much of our understanding of chemistry and materials science. Over the last decade or so, machine-learned force fields have transformed atomistic modeling by enabling simulations of ab initio quality over unprecedented time and length scales. However, early machine-learning (ML) force fields have largely been limited by (i) the substantial computational and human effort required to develop and validate potentials for each particular system of interest and (ii) a general lack of transferability from one chemical system to the next. Here, we show that it is possible to create a general-purpose atomistic ML model, trained on a public dataset of moderate size, that is capable of running stable molecular dynamics for a wide range of molecules and materials. We demonstrate the power of the MACE-MP-0 model—and its qualitative and at times quantitative accuracy—on a diverse set of problems in the physical sciences, including properties of solids, liquids, gases, chemical reactions, interfaces, and even the dynamics of a small protein. The model can be applied out of the box as a starting or “foundation” model for any atomistic system of interest and, when desired, can be fine-tuned on just a handful of application-specific data points to reach ab initio accuracy. Establishing that a stable force-field model can cover almost all materials changes atomistic modeling in a fundamental way: experienced users obtain reliable results much faster, and beginners face a lower barrier to entry. Foundation models thus represent a step toward democratizing the revolution in atomic-scale modeling that has been brought about by ML force fields.
KW - Materials Design
KW - Thermal Conducitivity
KW - Nanoparticles
KW - Batteries
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647829
DO - https://doi.org/10.1063/5.0297006
SN - 0021-9606
VL - 163
IS - 18
SP - 1
EP - 89
PB - AIP Publishing
AN - OPUS4-64782
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hahn, Marc Benjamin
T1 - Temperature effects in the Object Oriented Micromagnetic Framework (OOMMF) - OOMMF input parameter files for Tc determination
N2 - To simulate the movement of the macroscopic magnetic moment in ferromagnetic systems under the influence of elevated temperatures, the stochastic version of the Landau-Lifshitz (LL) or the Landau-Lifshitz-Gilbert equation with a spin density of one per unit cell has to be used.
To apply the stochastic LL to micromagnetic simulations, where the spin density per unit cell is generally higher, a conversion has to be performed. OOMMF sample files MIF) are provided which can be used to determine the Curie temperature for the classical bulk magnets, iron, nickel and cobalt.
KW - OOMMF
KW - Temperature
KW - Micromagnetism
KW - Thetaevolve
KW - Ferromagnetism
KW - Exchange interaction
KW - LLG
KW - Landau Lifshitz equation
KW - Magnetic moment
KW - Magnetic nanoparticles
KW - Object oriented micromagnetic framework
KW - Stochastic Landau Lifshitz Gilbert equation
KW - Temperature scaling
PY - 2020
DO - https://doi.org/10.26272/opus4-51169
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-51169
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hahn, Marc Benjamin
T1 - TOPAS cell model with nanoparticles
N2 - These files contain cell models for TOPAS/Geant4 and the inclusion of nano particles in particle scattering simulations. A simple spherical cell with nanoparticles can be generated in a fast manner. The user has the option to include the following organelles: nucleus, mitochondria, cell membrane. Additionally nanoparticles can be included in the cytosol and at the surface of the nucleus and/or the mitochondria.
The C++ classes in this repository extend the functionality of the TOPAS (http://www.topasmc.org/) Monte-Carlo program, which is itself a wrapper of the Geant4 MCS Toolkit (http://geant4.org). The sourcecode together with examples and scorers are provided.
"If you use this extension please cite the following literature:
Hahn, M.B., Zutta Villate, J.M. "Combined cell and nanoparticle models for TOPAS to study radiation dose enhancement in cell organelles." Sci Rep 11, 6721 (2021).
https://doi.org/10.1038/s41598-021-85964-2 "
KW - Monte-Carlo simulation
KW - MCS
KW - Geant4
KW - TOPAS
KW - TOPAS-nBio
KW - Dosimetry
KW - Nanoparticles
KW - Nanoparticle
KW - AuNP
KW - Gold
KW - Microdosimetry
KW - Targeted nanoparticle
KW - Simulation
KW - Particle scattering
KW - Cell
KW - Nucleus
KW - Mitochondria
KW - Cancer therapy
KW - Radiation therapy
PY - 2020
UR - https://github.com/BAMresearch/TOPAS-CellModels
UR - https://github.com/MarcBHahn/TOPAS-CellModels
DO - https://doi.org/10.26272/opus4-51150
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-51150
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hahn, Marc Benjamin
T1 - BioSAXS models for TOPAS/Geant4
N2 - Models for TOPAS/Geant4 to estimate the microscopic dose received by biomolecules during bioSAXS experiments.
The C++ classes in this repository extend the functionality of the TOPAS (http://www.topasmc.org/) Monte-Carlo program, which is itself a wrapper of the Geant4 MCS Toolkit (http://geant4.org).
KW - TOPAS
KW - TOPAS-nBio
KW - Geant4
KW - Geant4-DNA
KW - MCS
KW - Microdosimetry
KW - Protein
KW - Proteins
KW - Particle scattering
KW - G5P
KW - GV5
KW - SAXS
KW - Monte-Carlo simulation
KW - Dosimetry
KW - Micorscopic dose-damage relation
PY - 2022
UR - https://github.com/MarcBHahn/TOPAS-bioSAXS-dosimetry
DO - https://doi.org/10.26272/opus4-55751
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-55751
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - George, Janine
A1 - Ouellet-Plamondon, Claudiane
A1 - Reyes, Kristofer
T1 - Introduction to the “Accelerate Conference 2023–2024” themed collection
N2 - The collection showcases the ways in which automation, machine learning and robotics are transforming experimental materials science and chemistry into continuous, computationally integrated processes. It features innovations regarding autonomous laboratories, Bayesian optimisation, high-throughput experimentation and computation, and AI-driven literature extraction, which simplify and scale up materials discovery. Together, these works outline a modular, responsible framework for accelerating scientific progress through human-guided, data-driven autonomy.
KW - Automation
KW - Materials Acceleration Platforms
KW - Synthesizability
KW - Workflows
KW - Large Language Models
KW - Ontologies
KW - Materials Discovery
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654658
DO - https://doi.org/10.1039/d5dd90057c
SN - 2635-098X
SP - 1
EP - 2
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65465
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hahn, Marc Benjamin
A1 - Smales, Glen Jacob
A1 - Seitz, H.
A1 - Solomun, Tihomir
A1 - Sturm, Heinz
T1 - Ectoine interaction with DNA: Influence on ultraviolet radiation damage
N2 - Ectoine is a small zwitterionic osmolyte and compatible solute, which does not interfere with cell metabolism even at molar concentrations. Plasmid DNA (pUC19) was irradiated with ultraviolet radiation (UV-C at 266 nm) under quasi physiological conditions (PBS) and in pure water in the presence and absence of ectoine (THP(B)) and hydroxyectoine (THP(A)). Different types of UV induced DNA damage were analysed: DNA single-strand breaks (SSBs), abasic sites and cyclobutane pyrimidine dimers (CPDs). A complex interplay between these factors was observed with respect to the nature and occurrence of DNA damage with 266 nm photons. In PBS, the cosolutes showed efficient protection against base damage, whilst in pure water, a dramatic shift from SSB damage to base damage was observed when cosolutes were added. To test whether these effects are caused by ectoine binding to DNA, further experiments were conducted: small-angle X-ray scattering (SAXS), surface-plasmon resonance (SPR) measurements and Raman spectroscopy. The results show, for the first time, a close interaction between ectoine and DNA. This is in stark contrast to the assumption made by preferential exclusion models, which are often used to interpret the behaviour of compatible solutes within cells and with biomolecules. It is tentatively proposed that the alterations of UV damage to DNA are attributed to ectoine influence on nucleobases through the direct interaction between ectoine and DNA.
KW - Ectoine
KW - DNA
KW - Radiation damage
KW - Radiation protection
KW - SSB
KW - DNA damage
KW - DNA protection
KW - Compatible solute
KW - Zwitterion
KW - Hydroxyectoine
KW - Salt
KW - PBS
KW - UV absorption
KW - DNA strand-break
KW - DNA base damage
KW - Ectoine UV absorption
KW - Ectoine DNA protection
KW - Excited states
KW - UV irradiation
KW - UV-A
KW - UV-B
KW - UV-C
KW - 266nm
KW - UV photons
KW - Ectoine-DNA binding
KW - Raman spectroscopy
KW - UV-Vis
KW - Radical scavenger
KW - OH scavenger
KW - Hydroxyl radicals
KW - CPD
KW - Abasic site
KW - Agarose gel electrophorese
KW - SYBR gold
KW - DNA melting temperature
KW - Counterions
KW - Preferential exclusion
KW - Cancer
KW - Therapy
KW - UV protection
KW - Sunscreen
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505772
DO - https://doi.org/10.1039/d0cp00092b
SN - 1463-9076
SN - 1463-9084
VL - 22
IS - 13
SP - 6984
EP - 6992
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-50577
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Solomun, Tihomir
A1 - Hahn, Marc Benjamin
A1 - Smiatek, J.
T1 - Raman spectroscopic signature of ectoine conformations in bulk solution and crystalline state
N2 - Recent crystallographic results revealed conformational changes of zwitterionic ectoine upon hydration. By means of confocal Raman spectroscopy and density functional theory calculations, we present a detailed study of this transformation process as part of a Fermi resonance analysis. The corresponding findings highlight that all resonant couplings are lifted upon exposure to water vapor as a consequence of molecular binding processes. The importance of the involved molecular groups for water binding and conformational changes upon hydration is discussed. Our approach further Shows that the underlying rapid process can be reversed by carbon dioxide saturated atmospheres. For the first time, we also confirm that the conformational state of ectoine in aqueous bulk solution coincides with crystalline ectoine in its dihydrate state, thereby highlighting the important role of a few bound water molecules.
KW - Fermi resonance
KW - Ectoine hydration
KW - DFT calculations of Raman spectra
KW - Position of carboxylate group
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509855
DO - https://doi.org/10.1002/cphc.202000457
SN - 1439-4235
SN - 1439-7641
VL - 21
IS - 17
SP - 1945
EP - 1950
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-50985
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Silbernagl, Dorothee
A1 - Szymoniak, Paulina
A1 - Tavasolyzadeh, Zeynab
A1 - Sturm, Heinz
A1 - Topolniak, Ievgeniia
T1 - Interpenetrating Polymer Networks with Tuned Thermal and Mechanical Properties by Multiphoton Lithography
N2 - Multiphoton lithography (MPL) has recently attracted significant research interest as a versatile tool capable of fabricating 2D and 3D micro- and nanoscopic features with high spatial resolution. The integrity of MPL microstructures, or their ability to respond to external stimuli, is of critical importance. Often, the mechanically flexible micro-objects are expected to be capable of shape morphing, bending, or other motion to ensure their functionality. However, achieving the desired properties of MPL-manufactured micro components for a specific application still remains challenging.
In this work, we present new MPL materials based on epoxy-acrylate interpenetrating networks (IPNs). We aim at fabrication 3D microstructures, whose properties can be easily tuned by varying the ratio of the IPN components and fabrication parameters. The studied mixtures consist of polyethylene glycol diacrylate (PEGDA) and cycloaliphatic epoxide functional groups. Consequently, tryarylsylfonium salt and cyclopentanone photoinitiator tailored for MPL were used to ensure cationic and radical polymerization, respectively. The resulting library of 3D microstructures was investigated for their thermal and mechanical properties using highly sensitive space-resolved methods. For the first time, we were able to evaluate the glass transition behavior of 3D MPL microstructures using fast scanning calorimetry. The influence of both IPN composition and fabrication parameters on glass transition temperature and material fragility was demonstrated. AFM force-distance curve and intermodulation methods were used to characterize the micromechanical properties with lateral resolution of the techniques in the range of 1 micron and 4 nm, respectively. The elastic-plastic behavior of the microarchitectures was evaluated and explained in terms of IPN morphology and thermal properties. The fabricated 3D IPN microstructures exhibit higher structural strength and integrity compared to PEGDA. In addition, IPNs exhibit high to full elastic recovery (up to 100%) with bulk modulus in the range of 4 to 6 MPa. This makes IPNs a good base material for modeling microstructures with intricate 3D designs for biomimetics and scaffold engineering.
The effects of composition and MPL microfabrication parameters on the resulting IPN properties give us a better understanding of the underlying mechanisms and microfabrication-structure-property relationships. Moreover, our funding supports the further development of IPN systems as versatile and easily tunable MPL materials.
T2 - Material Research Society Meeting
CY - Boston, Massachusetts, USA
DA - 26.11.2023
KW - Multiphoton Lithography
KW - Two-photon polymerisatio
KW - Interpenetrating polymer network
PY - 2023
SP - 1
AN - OPUS4-59382
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Silbernagl, Dorothee
A1 - Szymoniak, Paulina
A1 - Tavasolyzadeh, Zeynab
A1 - Sturm, Heinz
A1 - Topolniak, Ievgeniia
T1 - Interpenetrating networks with tuned thermal and mechanical properties
N2 - Multiphoton lithography (MPL), an emerging microfabrication technique, shows great potential in a variety of applications ranging from tissue engineering to soft micro-robotics. Fabricated micro-objects often are expected to undergo shape morphing or bending. Furthermore, ensuring precise property tuning becomes detrimental for the functionality of MPL microstructures. Herein, we present novel MPL materials based on interpenetrating networks (IPNs), which effectively combine the advantages of acrylate and epoxy thermoset systems. A library of 3D MPL IPN microstructures with high 3D structural stability and tailored thermal and micromechanical properties is achieved. MPL laser velocity and fabrication power can be used to tune the morphology and therefore properties of IPN. New IPN microstructures with materials Young's moduli of 4 to 6 MPa demonstrate susceptibility to deformation with high to fully elastic response. Such soft elastic materials hold immense promise within morphable microsystems, soft micro-robotics and cell engineering applications.
T2 - RSC Poster conference
CY - Online meeting
DA - 05.03.2024
KW - Multiphoton lithography
KW - Interpenetrating polymer networks
KW - AFM
PY - 2024
AN - OPUS4-60060
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Topolniak, Ievgeniia
T1 - Direct laser writing of mussel inspired polydopamine
N2 - Polydopamine (PDA) is one of the simplest and most versatile approaches for forming an excellent binding exterior to confer new functionalities to nearly any material surface. Inspired by nature, it mimics the behavior of mussels and can be easily deposited on virtually all types of inorganic and organic substrates, including superhydrophobic surfaces. Moreover, PDA exhibits high potential for surface modification and diversified secondary reactions that makes it extremely interesting for a wide range of application including biomedical field, e.g., drug delivery, adhesives, cell adhesion, biosensing. PDA has undergone significant expansion in its applications and is one of the most attractive areas within the materials field. Nevertheless, PDA integration in microdevices is still constrained by poor spatial and temporal control of excited deposition methods.
Herein, we demonstrate a novel maskless approach for PDA micropatterning based on Direct Laser Writing that overcomes present limitations. The pattern is formed upon exposure of the dopamine solution by light produced by tightly-focused fs NIR laser that scans substrate surface accordingly to the selected pattern design. Neither strong oxidants, metal ions nor adjusting pH to alkaline is required by this technique to perform dopamine polymerization. Our method achieves the PDA micropatterns with the spatial resolution of 0.8 µm, at least an order of magnitude smaller than what is possible with other PDA microplanning techniques. Some examples of PDA patterns are shown in Figure 1. The here introduced PDA deposition technique will uniquely unravel applications of polydopamine and other catecholamine-based mussel-inspired materials in various multifunctional systems and microdevices (e.g., MEMS elements, microfluidics).
The chemical nature of PDA was confirmed by locally recorded vibrational and x-ray photoelectron spectra. Moreover, the morphology and thickness of PDA microstructure can be controlled by the laser power and scanning velocity revealing the possibility of fabricating the structures with gradient. In most of the applied conditions the increase of the laser intensity and decrease of the scanning velocity would lead to the thicker PDA pattern. Different morphologies from smooth and bulky-like to grain like has been obtained.
PDA was produced in the presence of tris buffer, phosphate buffer and DI water only. We also tested the effect of the solution pH applying pH 6.0, 7.0 and 8.5. Furthermore, the effect of antioxidants and purging of the solution with oxygen and nitrogen was investigated. Summarizing, we could see that the structures could be produced in all the given conditions, however their thickness and quality, morphology and roughness would differ. We did not observe negative impact of the antioxidants and nitrogen purging on the performance of PDA build up indicating that the PDA formation mechanism is different to common autooxidation. The current mechanism is based on the interaction of dopamine molecules with the photoinitiator added to solution as active to DLW laser light component.
Apart from the glass substrate, we achieved PDA patterning at surfaces of different nature such as polychlorotrifluoroethylene, polydimethylsiloxane, polyethylene terephthalate, silicon wafers, and fluorinated glass coverslips.
We also performed facile posts-modification of the PDA surface with protein enzymes like trypsin that was confirmed by XPS. Obtained bioactive pattern could be further integrated in the protein sensing devices.
Presented in this work DLW-based microfabrication technique and the possibilities for further PDA surface post-functionalization empowers advanced applications of this material in single-molecule bioassays, sensors and other complex microdevices.
T2 - MNE EUROSENSORS
CY - Leuven, Belgium
DA - 19.09.2022
KW - Polydopamine
KW - Two-photon polymerisation
KW - Micropatterning
PY - 2022
AN - OPUS4-56421
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - INPR
A1 - Naik, Aakash A.
A1 - Dhamrait, Nidal
A1 - Ueltzen, Katharina
A1 - Ertural, Christina
A1 - Benner, Philipp
A1 - Rignanese, Gian-Marco
A1 - George, Janine
T1 - A critical assessment of bonding descriptors for predicting materials properties
N2 - Most machine learning models for materials science rely on descriptors based on materials compositions and structures, even though the chemical bond has been proven to be a valuable concept for predicting materials properties. Over the years, various theoretical frameworks have been developed to characterize bonding in solid-state materials. However, integrating bonding information from these frameworks into machine learning pipelines at scale has been limited by the lack of a systematically generated and validated database. Recent advances in high-throughput bonding analysis workflows have addressed this issue, and our previously computed Quantum-Chemical Bonding Database for Solid-State Materials was extended to include approximately 13,000 materials. This database is then used to derive a new set of quantum-chemical bonding descriptors. A systematic assessment is performed using statistical significance tests to evaluate how the inclusion of these descriptors influences the performance of machine-learning models that otherwise rely solely on structure- and composition-derived features. Models are built to predict elastic, vibrational, and thermodynamic properties typically associated with chemical bonding in materials. The results demonstrate that incorporating quantum-chemical bonding descriptors not only improves predictive performance but also helps identify intuitive expressions for
properties such as the projected force constant and lattice thermal conductivity via symbolic regression.
KW - Bonding Analysis
KW - Machine Learning
KW - Symbolic Regression
KW - Chemical Understanding
KW - Phonons
KW - Thermal Conductivity
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655150
DO - https://doi.org/10.48550/arXiv.2602.12109
SP - 1
EP - 28
PB - Cornell University
CY - Ithaca, NY
AN - OPUS4-65515
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Fritzsche, Sven
A1 - Weimann, Christiane
A1 - Pauw, Brian Richard
A1 - Sturm, Heinz
T1 - 2PP-TestArtifact
N2 - This repository contains a test artifact (TA), also called test structure, designed for two-photon polymerization (also known as Direct Laser Writing (DLW) or Two/Multi-photon lithography (2PA/MPA)). Test artifacts can be used to compare structures, to check options used by the slicer, check the state of the 2PP machine itself or to get a construction guidelines for a certain combination of power, velocity and settings.
The associated paper can be found here: https://dx.doi.org/10.1088/1361-6501/acc47a
General ideas behind the test artifact:
1. optimized for 2PP-DLW
2. should be fast and easy to analyse with optical microscopy or 3. scanning electron microscopy without tilt.
3. short time to fabricate
4. include a reasonable amount of different features
5. bulk and small structures on the substrate
KW - Reference structure
KW - Calibration structure
KW - Test structure
KW - Laser writing
KW - Two-photon polymerization
KW - 3D printing
KW - Additive manufacturing
KW - Microprinting
KW - Multi-photon light structuring
PY - 2023
DO - https://doi.org/10.6084/m9.figshare.22285204.v2
PB - Digital Science
CY - Cambridge, MA, USA
AN - OPUS4-57165
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fornacon-Wood, Christoph
A1 - Stühler, Merlin R.
A1 - Millanvois, Alexandre
A1 - Steiner, Luca
A1 - Weimann, Christiane
A1 - Silbernagl, Dorothee
A1 - Sturm, Heinz
A1 - Paulus, Beate
A1 - Plajer, Alex J.
T1 - Fluoride recovery in degradable fluorinated polyesters
N2 - We report a new class of degradable fluorinated polymers through
the copolymerization of tetrafluorophthalic anhydride and propylene
oxide or trifluoropropylene oxide which show up to 20 times
quicker degradation than the non-fluorinated equivalents and allow
for fluoride recovery.
KW - Fluoropolymers
KW - Recycling
KW - PFAS
KW - AFM force distance curves
KW - AFM plastic deformation
KW - AFM friction analysis
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-606768
DO - https://doi.org/10.1039/d4cc02513j
VL - 60
SP - 7479
EP - 7482
PB - Royal Society of Chemistry
AN - OPUS4-60676
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - THES
A1 - Kittner, Maria
T1 - Entwicklung eines Konzeptes zur verbesserten Abbaubarkeit von Polymeren unter realitätsnahen Umweltbedingungen
N2 - Das Ziel dieses Grundlagenforschungsprojektes war, die Abbaubarkeit syntheti-scher Polymere unter realitätsnahen Umweltbedingungen durch eine Mischung bzw. Blend eines Hydrolyse- mit einem Oxidations-empfindlichen Polymer zu verbessern, während er unter Nutzungsbedingungen stabil sein sollte. Die Arbeits-hypothese war, dass sich die Polymere gegenseitig in ihrem Abbau beschleunigen, wenn sie der alternierenden Wechselbeanspruchung aus UV-Strahlung und hydrolytischer Beanspruchung ausgesetzt sind. Hierfür wurden vier Blends aus Polylactid (PLA) und Polystyrol (PS) oder Polymethylmethacrylat (PMMA) in unterschiedlichen Mischverhältnissen und Phasenstrukturen mittels additiver Fertigung hergestellt. Die Blends wurden über acht Wochen bei 45 °C mittels alternierender Wechselbeanspruchung aus je fünf Tagen UV-Bestrahlung und zwei Tagen hydrolytischer Beanspruchung beschleunigt gealtert. Für eine Basis-charakterisierung und als Vergleichsgrundlage wurden zusätzlich die Ausgangs-polymere PLA, PS und PMMA jeweils einzeln der hydrolytischen Beanspruchung, UV-Beanspruchung und alternierenden Wechselbeanspruchung unterzogen. Neben der Bestimmung der physiko-chemischen Effekte auf Prüfkörperoberflächen und Bulk wurden erstmalig auch die Wassermedien auf Mikroplastikgehalte und ökotoxikologische Wirkungen analysiert.
Die Ergebnisse ergaben, dass reines PLA kaum degradierte, aber der PLA-Abbau sowohl durch Mischung mit PS als auch PMMA verstärkt wurde. Entgegen der Hypothese wurde dadurch allerdings sowohl die Degradation von PS als auch von PMMA gehemmt. Es konnte gezeigt werden, dass sich PS und PMMA im Blend mit PLA durch radikalische Depolymerisation abbauten und die dabei entstehenden Radikale die PLA-Hydrolyse beschleunigten, was wiederum den Abbau der PS- und PMMA-Phasen verlangsamte. Die Ergebnisse zeigten, dass bei dem PLA/PS-Schichtblend (PLA/PS-50) der höchste PS-Gehalt von 50 % den stärksten Effekt auf den PLA-Abbau hatte. Insgesamt war allerdings selbst in diesem Fall die PLA-Degradation nach achtwöchiger Beanspruchung als gering einzustufen. Der totale Masseverlust von PLA/PS-50 entsprach nach achtwöchiger Wechselbeanspruchung -2,6 ± 0,2 mg absolut bzw. ca. -1,5 ± 0,1 % der Prüfkörpermasse, wovon 0,001 % in partikuläres Mikroplastik fragmentierte (PLA: 0,2 – 2,7 μg/g; PS: 3,0 – 3,4 μg/g). Folglich war der größte Teil des Masseverlustes der Prüfkörper auf die Bildung gelöster und/oder gasförmiger Degradationsprodukte zurückzuführen.
Ferner zeigten ökotoxikologische Untersuchungen der wechselbeanspruchten Wassermedien von PLA/PS-50 eine zunehmende Hemmung des Algenwachstums der Grünalge Desmodesmus subspicatus, die nach sechs Wochen Wechsel-beanspruchung zu 100 % Hemmung und nach acht Wochen zu einem Absterben der eingesetzten Algenzellen führte. Ergänzende Algenwachstumshemmungstests mit
2
Prüfkörpern der Ausgangspolymere PLA und PS zeigten, dass dies nicht auf der Bildung von partikulärem Mikroplastik, sondern gelösten PS-Degradations-produkten basierte, wie z. B. Benzaldehyd oder Benzoesäure.
Zusammenfassend lässt sich sagen, dass nur eine geringe Beschleunigung des PLA-Abbaus bei gleichzeitiger Hemmung des PS- bzw. PMMA-Abbaus stattfand - und das auch erst bei hohen PS- bzw. PMMA-Gehalten. Weiterführende Experimente zeigten, dass dies speziell für PS höchst bedenklich und nicht empfehlenswert ist, da es abhängig von der Konzentration der gelösten PS-Degradationsprodukte zu starken ökotoxikologischen Effekten kommen kann, die von der Hemmung des Algen-wachstums bis zum Algenabsterben reichen können. Folglich konnte die Arbeits-hypothese nur sehr eingeschränkt verifiziert werden und ist mit den hier untersuchten Polymeren als nicht zielführend einzuschätzen.
KW - Polymer
KW - Blend
KW - Microplastik
KW - Degradation
KW - Umweltsimulation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609879
DO - https://doi.org/10.14279/depositonce-21006
SP - 1
EP - 109
PB - Depostit Once
CY - Berlin
AN - OPUS4-60987
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Waniek, Tassilo
A1 - Omar, Hassan
A1 - Szymoniak, Paulina
A1 - Silbernagl, Dorothee
A1 - Sturm, Heinz
T1 - The influence of water released from particles in epoxy‐based nanocomposites
N2 - AbstractRecent studies have hypothesized that the reinforcing effects of boehmite nanoparticles (BNPs) in polymer nanocomposites (PNCs) are partly related to the particles themselves and partly to the water released from the BNP during curing. In this work, PNCs made from dried BNP (dBNP) with concentrations up to 15 wt% are investigated to differentiate particle and water related effects. The observed trend of the storage modulus in dynamic mechanical thermal analysis measurements was found to be independent of the drying procedure. Stiffness maps from intermodulation atomic force microscopy showed that dBNP leads to a stiffening of the interphase surrounding the particles compared with the unaffected epoxy matrix, while a softer interphase was reported for PNCs with as received BNP. A slight decrease in the glass transition temperature was observed by broadband dielectric spectroscopy related to a lowered crosslink density due to the particles. A significantly higher decrease was reported for PNCs with BNP, attributed to water influencing the curing process. In conclusion, the stiffening of PNC with BNP is related to the particles themselves, while the release of water causes the formation of a soft interphase in the vicinity of the particles and a significant decrease in crosslink density.
KW - AFM stiffness of interface
KW - Aluminium oxide hydroxide
KW - Boehmit nanoparticle
KW - Glass transition temperature
KW - Broadband dielectric spectroscopy
KW - Crosslink density control
KW - Structure–property relationship
KW - Nanocomposites
KW - Thermoset
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-606772
DO - https://doi.org/10.1002/app.55937
SN - 0021-8995
SP - 1
EP - 16
PB - Wiley
AN - OPUS4-60677
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Campbell, C. G.
A1 - Jordon Astorga, D.
A1 - Dümichen, Erik
A1 - Celina, M.
T1 - Thermoset materials characterization by thermal desorption or pyrolysis based gas chromatography-mass spectrometry methods
N2 - Thermoset materials characterization is often limited to solid state analytical techniques such as IR, NMR, DSC, TGA and mechanical testing. Alternatively, their off-gassing behavior can also be evaluated using GC based techniques such as TD-GC-MS, allowing this method to be applied to thermoset materials analyses such as identification, aging characterization, and formulation optimization. As an overview, common thermoset materials were evaluated by analyzing their gaseous degradation products via TGA-based pyrolysis and subsequent TD-GC-MS for the identification of representative volatile signatures. It is thereby possible to distinguish different classes of phenolic materials or cured epoxy resins, as well as their amine or anhydride curatives. Additionally, this method enabled quantification of a volatile fragment (bisphenol A, BPA) which is associated with oxidation of epoxy/amine thermoset materials. The amount of evolved BPA increased linearly with aging time and this trend exhibits linear Arrhenius behavior over the temperature range (80–125 °C) studied, in agreement with oxidation sensitivies based on oxygen consumption data. Further, TD-GC-MS was used to explore how off-gassing of residual anhydride curative from an epoxy/anhydride material depends on formulation stoichiometry. Even in formulations that theoretically contained enough epoxy to consume all anhydride (1:1 stoichiometry), an imperfect final cure state resulted in residual anhydride which could evolve from the material. For such materials, a slightly epoxy-rich formulation is required to ensure that the material contains no residual unreacted anhydride. Analysis of volatiles generated by thermal exposure is an attractive characterization approach enabling compositional analysis as well as complementary diagnostics for materials degradation.
KW - Polymer analysis/characterization
KW - Thermal desorption mass spectrometry
KW - Thermoset composition
KW - Volatiles from thermosets
KW - Degradation signatures
PY - 2020
DO - https://doi.org/10.1016/j.polymdegradstab.2019.109032
VL - 174
SP - 109032
PB - Elsevier Ltd.
AN - OPUS4-50435
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Cano Murillo, Natalia
A1 - Ghasem Zadeh Khorasani, Media
A1 - Silbernagl, Dorothee
A1 - Hahn, Marc Benjamin
A1 - Hodoroaba, Vasile-Dan
A1 - Sturm, Heinz
T1 - Cover image for the article "Nanomechanical study of polycarbonate/boehmite nanoparticles/epoxy ternary composite and their interphases"
N2 - The image designed by Natalia Cano Murillo and colleagues shows the cross section of a ternary composite (boehmite/polycarbonate/epoxy, 80μm x 80μm). The surface was measured by AFM kelvin probe microscopy, yielding the surface potential which is shown as 3D‐surface and contour lines. The sample was further subjected to AFM force spectroscopy with a lateral resolution of 1μm², yielding the local Young's modulus, projected in false colors on the 3D surface. The ternary system, containing boehmite nanoparticles, shows a broad distribution of modulus, desirable for optimized macroscopic mechanical properties, such as high stiffness as well as toughness.
KW - Boehmite
KW - Epoxy
KW - Polycarbonate
KW - AFM
KW - BNP
PY - 2020
DO - https://doi.org/10.1002/app.50400
SN - 0021-8995
SN - 1097-4628
VL - 138
IS - 12
SP - 1
PB - Wiley
CY - New York, NY
AN - OPUS4-51831
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Topolniak, Ievgeniia
T1 - Micropatterning of mussel-inspired materials - Empower selective functionality
N2 - Surface-modification platforms that are universally applicable are vital for the development of new materials, surfaces, and nanoparticles. Mussel-inspired materials (MIMs) are widely used in various fields because of their strong adhesive properties and post-functionalization reactivity. However, conventional MIM coating techniques have limited deposition selectivity and lack structural control, which has limited their use in microdevices that require full control over deposition. To overcome these limitations, we developed a micropatterning technique for MIMs using multiphoton lithography, which does not require photomasks, stamps, or multistep procedures. This method enables the creation of MIM patterns with micrometer resolution and full design freedom and paves the way for innovative applications of MIMs in various multifunctional systems and microdevices, such as microsensors, MEMS, and microfluidics.
T2 - BioCHIP Berlin - International Forum on Biochips and Microfabrication
CY - Berlin, Germany
DA - 28.05.2024
KW - Mussel inspired materials
KW - Multiphoton lithography
KW - Two photon polymerisation
PY - 2024
AN - OPUS4-60254
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Robust Data Generation, Heuristics and Machine Learning for Materials Design
N2 - My talk covered, among other things, robust data generation for machine learning. It showed how heuristics can be used within machine learning models and how they might also be extracted from machine learning models. Beyond this, I showed an automated pipeline for training machine learning potentials.
T2 - Workshop on AI in Sustainable Materials Science
CY - Düsseldorf, Germany
DA - 27.01.2026
KW - Automation
KW - Digitalisation
KW - Materials Design
KW - Thermal Conductivity
KW - Chemical bonding
KW - Materials Acceleration Platforms
PY - 2026
AN - OPUS4-65427
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Robust Data Generation, Heuristics and Machine Learning for Materials Design
N2 - My talk covered, among other things, robust data generation for machine learning. It showed how heuristics can be used within machine learning models and how they might also be extracted from machine learning models. Beyond this, I showed an automated pipeline for training machine learning potentials.
T2 - Seminar Gruppe Stephan Roche
CY - Barcelona, Spain
DA - 22.01.2026
KW - Automation
KW - Machine Learning
KW - Materials Acceleration Platforms
KW - Thermal Conductivity
KW - Phonons
KW - Bonding Analysis
PY - 2026
AN - OPUS4-65428
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Janssen, Jan
A1 - George, Janine
A1 - Geiger, Julian
A1 - Bercx, Marnik
A1 - Wang, Xing
A1 - Ertural, Christina
A1 - Schaarschmidt, Jörg
A1 - Ganose, Alexander Miguel
A1 - Pizzi, Giovanni
A1 - Hickel, Tilmann
A1 - Neugebauer, Jörg
T1 - A Python workflow definition for computational materials design
N2 - Numerous Workflow Management Systems (WfMS) have been developed in the field of computational materials science with different workflow formats, hindering interoperability and reproducibility of workflows in the field. To address this challenge, we introduce here the Python Workflow Definition (PWD) as a workflow exchange format to share workflows between Python-based WfMS, currently AiiDA, jobflow, and pyiron. This development is motivated by the similarity of these three Python-based WfMS, that represent the different workflow steps and data transferred between them as nodes and edges in a graph. With the PWD, we aim at fostering the interoperability and reproducibility between the different WfMS in the context of Findable, Accessible, Interoperable, Reusable (FAIR) workflows. To separate the scientific from the technical complexity, the PWD consists of three components: (1) a conda environment that specifies the software dependencies, (2) a Python module that contains the Python functions represented as nodes in the workflow graph, and (3) a workflow graph stored in the JavaScript Object Notation (JSON). The first version of the PWD supports directed acyclic graph (DAG)-based workflows. Thus, any DAG-based workflow defined in one of the three WfMS can be exported to the PWD and afterwards imported from the PWD to one of the other WfMS. After the import, the input parameters of the workflow can be adjusted and computing resources can be assigned to the workflow, before it is executed with the selected WfMS. This import from and export to the PWD is enabled by the PWD Python library that implements the PWD in AiiDA, jobflow, and pyiron.
KW - Worklows
KW - FAIR Workflows
KW - Automation
KW - Materials Acceleration Platforms
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643325
DO - https://doi.org/10.1039/D5DD00231A
SN - 2635-098X
SP - 1
EP - 14
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-64332
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Topolniak, Ievgeniia
T1 - Direct laser surface micropatterning with polydopamine
N2 - Inspired by the chemistry of mussel adhesive proteins, polydopamine (PDA) is one of the simplest and most versatile approaches to confer new functionalities to nearly any material surface. Moreover, PDA exhibits high potential for surface modification and diversified secondary reactions that makes it extremely interesting for a wide range of application including biomedical field, e.g., drug delivery, adhesives, cell adhesion, biosensing. PDA has undergone significant expansion in its applications and is one of the most attractive areas within the materials field. Nevertheless, PDA integration in microdevices is still constrained by poor spatial and temporal control of excited deposition methods.
Herein, we demonstrate a novel maskless approach for PDA micropatterning based on Direct Laser Writing (DLW) that overcomes present limitations. The pattern is formed upon exposure of the dopamine solution by light produced by tightly-focused fs NIR laser that scans substrate surface accordingly to the selected pattern design. Neither strong oxidants, metal ions nor adjusting pH to alkaline is required by this technique. Our method achieves the PDA micropatterns with the spatial resolution of 0.8 µm, at least an order of magnitude smaller than what is possible with other PDA microplanning techniques. The here introduced PDA deposition technique will uniquely unravel applications of polydopamine and other catecholamine-based mussel-inspired materials in various multifunctional systems and microdevices (e.g., MEMS elements, microfluidics).
Adjustment of MPL parameters revealed that the morphology and thickness of resulted PDA microstructures can be controlled by altering the laser power and its scanning velocity. As a result, it also enables the production of micropatterns with structural gradient.
Apart from the glass substrate, we achieved PDA patterning at surfaces of different nature such as polychlorotrifluoroethylene, polydimethylsiloxane, polyethylene terephthalate, silicon wafers, and fluorinated glass coverslips.
The chemical nature of PDA was confirmed by locally recorded vibrational and x-ray photoelectron spectra. To ensure post-modification potential of MPL deposited PDA we demonstrated one-step deposition of micropatterns with trypsin. Obtained bio-functionalised surface can be further applied as a protein sensing active microelement.
Presented in this work DLW-based microfabrication technique and the possibilities for further PDA surface post-functionalization empowers advanced applications of this material in single-molecule bioassays, sensors and other complex microdevices.
T2 - Swiss ePrint 2022
CY - Buchs, Switzerland
DA - 05.09.2022
KW - Polydopamine
KW - Two-photon polymerisation
KW - Micropatterning
PY - 2022
AN - OPUS4-56422
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dittrich, Maria
A1 - Paulo, Carlos
A1 - Knabe, Nicole
A1 - Sturm, Heinz
A1 - Zaitsev, Vladimir
A1 - Gorbushina, Anna
T1 - Microscopic Raman study of fungal pigment using the genetically amenable rock inhabitant Knufia petricola as a model organism
N2 - Fungal pigments such as melanin and carotenoids are distinctive markers of animal and plant pathogenic fungi as well as their environmental relatives. These complex pigments play important roles in pathogenicity and stress tolerance while also being useful as biomarkers. Accordingly, it is important to be able to identify in situ the pigments in black fungi, a group of clinical and environmental importance. In this study, wild-type and genetically modified strains of Knufia petricola A95 and wild fungal cells attached to ancient rock were investigated for their spectroscopic and microscopic Raman features and morphological appearance. Knockout mutants of melanin synthesis genes pks1 (polyketide synthase), sdh1 (scytalone dehydratase), and both pks1 and the carotenoid synthesis gene phd1 (phytoene desaturase) were studied We applied two different Raman microscopes using two lasers, with 633 nm and 488 nm wavelengths. We analyzed and compared Raman spectra between the measured reference substances and the mutant and wild-type strains. In the wild strain WT:A95, the peaks close to melanin peals were found at 1353 cm−1 and 1611 cm−1. There are no characteristic melanin peaks at 1580–1600 cm−1 and around 1350 cm−1 at the spectrum of the Δpks1/Δphd1 mutant and the Δsdh1 mutant. The Δpks1 mutant spectrum has the peaks at the beta-carotene v2 C-C in-plane stretch at 1155 cm−1 and v3 C-CH3 deformation at 1005 cm−1. The peaks of carotenoids and melanin were found in all mutants and the wild strain, except the Δpks1/Δphd1 mutant. Raman spectra allow for discrimination between the various pigments. Hence, interactions between natural fungal melanin, as well as other protective pigments, and complex environmental matrices can be characterized on a range of spatial and temporal scales.
KW - Raman Spectroscopy
KW - Instrumentation
KW - Analytical Chemistry
KW - Knufia petricola
KW - Confocal microscopy
KW - Atomic and Molecular Physics and Optics
PY - 2023
DO - https://doi.org/10.1016/j.saa.2023.123250
SN - 1386-1425
VL - 303
SP - 1
EP - 11
PB - Elsevier BV
AN - OPUS4-58792
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Silbernagl, Dorothee
A1 - Szymoniak, Paulina
A1 - Tavasolyzadeh, Zeynab
A1 - Sturm, Heinz
A1 - Topolniak, Ievgeniia
T1 - Interpenetrating networks with tuned thermal and mechanical properties
N2 - Text Multiphoton lithography (MPL) has recently attracted significant research interest as a versatile tool capable of producing 2D and 3D micro- and nanoscopic features with high spatial resolution. The integrity of MPL microstructures, or their ability to respond to external stimuli, is of critical importance. However, achieving the desired properties of fabricated microcomponents for a specific application remains a challenge.
In this work, we present new MPL materials based on epoxy-acrylate interpenetrating networks (IPNs). We aim at 3D microstructures, whose properties can be easily tuned by varying the ratio of the IPN components and fabrication parameters (Figure 1). The resulting library of 3D microstructures was investigated for their thermal and mechanical properties using highly-sensitive space-resolved methods. Flash scanning calorimetry revealed the influence of both, IPN composition and fabrication parameters, on glass transition temperature and material fragility. AFM force-distance curve and intermodulation methods were used to characterize the mechanical properties with a lateral resolution of 1 micron and 4 nm, respectively. The deformation, stiffness and elastic behavior are discussed in detail in relation to the morphology. Moreover, we found that some 3D IPN microstructures exhibit fully elastic behavior. Our funding encourages the further development of IPN systems as versatile and easily tunable MPL materials.
T2 - Micro Nano Engineering (MNE conference)
CY - Berlin, Germany
DA - 25.09.2023
KW - Interpenetrating polymer network
KW - Multiphoton Lithography
KW - Two photon polymerisation
KW - Direct laser writing
KW - Polyethylene glycol diacrylate
PY - 2023
AN - OPUS4-58879
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - Ectoine protects biomolecules from ionizing radiation: Molecular mechanisms
N2 - The compatible solute and osmolyte ectoine is an effective protectant of biomolecules and whole cells against heating, freezing and high salinity. The protection of cells (human Keratinocytes) by ectoine against ultraviolet radiation was also reported by various authors, although the underlying mechanism is not yet understood. We present results on the irradiation of biomolecules (DNA) with ionizing radiation (high energy electrons) in fully aqueous environment in the presence of ectoine and high salt concentrations. The results demonstrate an effective radiation protection of DNA by ectoine against the induction of single strand breaks by ionizing radiation. The effect is explained by an increased in low-energy electron scattering at the enhanced free-vibrational density of states of water due to ectoine, as well as the action of ectoine as an OH-radical scavenger. This was demonstrated by Raman spectroscopy, electron paramagnetic resonance (EPR) and Monte-Carlo simulations (Geant4).
T2 - #RSCposter 2023
CY - Online meeting
DA - 28.02.2023
KW - Compatible solute
KW - Dosimetry
KW - Ectoine
KW - Ectoin
KW - Ectoine radiation protection
KW - Ectoine radical scavenger
KW - Geant4
KW - Geant4-DNA
KW - Hydroxyectoine
KW - Hydroxyl radical
KW - Ionizing radiation
KW - Low energy electrons
KW - LEE
KW - OH-radical
KW - DNA
KW - Osmolyte
KW - Radiation damage
KW - Radiation protection
KW - Radical scavenger
KW - Radiation therapy
PY - 2023
AN - OPUS4-57061
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Fritzsche, Sven
A1 - Pauw, Brian Richard
A1 - Weimann, Christiane
A1 - Sturm, Heinz
T1 - Test artifact for fs-LDW
N2 - Data to generate the given graphs in the publication as well as raw images of the shown images.
KW - stl code
KW - Images
KW - Graphs
KW - Data
PY - 2023
DO - https://doi.org/10.5281/zenodo.7671945
PB - Zenodo
CY - Geneva
AN - OPUS4-58096
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CHAP
A1 - Zarinwall, A.
A1 - Waniek, Tassilo
A1 - Finke, B.
A1 - Sadaat, R.
A1 - Sturm, Heinz
A1 - Garnweitner, G.
ED - Sinapius, M.
ED - Ziegmann, G.
T1 - Particle Surface Modification
N2 - Whilst a decisive role of the particle-matrix interphase on the mechanical properties of nanoparticle-filled polymers has been demonstrated in the last years, the arbitrary design of this interphase remains a very challenging goal. In principle, this could be realized via an appropriate surfacemodification of the nanofiller prior to its incorporation in the polymer. For most systems, such as for boehmite nanofillers, however, the interaction of organic modifiers with the particle surface has not been studied in detail, and only single studies are known rather than systematic investiga- tions on the effects of different chemical functions anchored on the particle surface. In this chapter, we present an extensive study on the binding of APTES, a common silane surface modifier, with boehmite, and show that thermogravimetric analysis (TGA) coupled with mass spectrometry (MS) is a convenient and highly suitable method to elucidate the ligand binding in detail. Furthermore, a two-step coupling strategy is presented, demonstrating that based on APTES anchored to the parti- cle surface, the condensation of various carboxylic acids can be utilized to enable highly diverse chemical properties of the nanofillers, which leads to very different particle-matrix interactions in the nanocomposites.
KW - APTES
KW - Boehmite
KW - Nanoparticle
KW - TGA-MS
PY - 2021
SN - 978-3-030-68522-5
SN - 978-3-030-68523-2
DO - https://doi.org/10.1007/978-3-030-68523-2
SN - 2194-8240
SN - 2194-8259
SP - 119
EP - 142
PB - Springer Nature Switzerland AG
CY - Cham
AN - OPUS4-53727
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cano Murillo, Natalia
A1 - Szymoniak, Paulina
A1 - Smales, Glen Jacob
A1 - Sturm, Heinz
A1 - Schönhals, Andreas
T1 - Electrospun nanocomposites fibers of polycarbonate and taurine modified boehmite nanoparticles - What can be learned from structural and thermal investigations
N2 - Though the reinforcing properties of inorganic particles in thermosetting nanocomposites, has been exploited, the integration of nanoparticles continues to be challenging in terms of their homogeneous distribution and their manipulation which can contribute to occupational hazards. Due to a second encapsulations of nanoparticles, electrospun nanocomposite fibers containing nanoparticles might be an alternative for overcoming these issues, as the fiber nonwovens contains the nanoparticles allowing for safer manipulation. Here, the morphology, and the thermal properties of electrospun polycarbonate fibers containing taurine modified boehmite nanoparticles (BNP) are investigated by means of small and wide-angle X-ray scattering as well as fast scanning and temperature modulated fast scanning calorimetry for the first time. The latter techniques allow the investigation of the thermal properties of single fibers at heating rates up to 10^4 K s^-1 keeping its structure intact. A quantitative analysis of the scattering data reveals a porous structure of the fibers. The porous structure is quantified regarding the pore volume and the pore size. A constant amount of aggregation is found even for the highly BNP loaded fibers. Thermal analysis on the fibers reveals a rigid amorphous fraction (RAF) where it is known that RAF determinates the properties of a nanocomposite to a large extent. For the fibers RAF amounts up to 40 wt%, which is essential higher compared to equally formulated PC/BNP composite cast films. The RAF in the case of the fibers, is not only due to the presence of particles in the polymer but also due to orientation effects induced by the electrospinning process.
KW - Nanocomposite fibers
KW - Electrospinning
KW - X-ray scattering
KW - Fast scanning calorimetry
KW - Rigid amorphous fraction
PY - 2021
DO - https://doi.org/10.1021/acsapm.1c01265
VL - 3
IS - 12
SP - 6572
EP - 6585
PB - ACS
AN - OPUS4-53871
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CHAP
A1 - Szymoniak, Paulina
A1 - Qu, Xintong
A1 - Schönhals, Andreas
A1 - Sturm, Heinz
ED - Sinapius, M.
ED - Ziegmann, G.
T1 - Characterization of Polymer Nanocomposites
N2 - The complex effect of nanoparticles on an epoxy-based and anhydride cured DGEBA/Boehmite nanocomposite with different particle concentrations is considered in this chapter. A combination of X-ray scattering, calorimetry (fast scanning and temperature modulated calorimetry) and dielectric spectroscopy was employed to characterize the structure, vitrification kinetics and the molecular dynamics of the nanocomposites. Firstly, the unfilled polymer was found to be intrinsically heterogeneous, showing regions with different crosslinking density, indicated by two separate dynamic glass transitions. Moreover, the glass transition temperature decreases with increasing nanoparticle concentration, as a result of changes in the crosslinking density. In addition, it was shown that the incorporation of nanoparticles can result in simultaneous increase in the number of mobile segments for low nanoparticle concentrations and on the other hand, for higher loading degrees the number of mobile segments decreases, due to the formation of an immobilized interphase.
KW - Rigid amorphous fraction
KW - Epoxy nanocomposites
KW - X-ray scattering
KW - Differential scanning calorimetry
KW - Broadband dielectric spectroscopy
KW - Flash DSC
PY - 2021
DO - https://doi.org/10.1007/978-3-030-68523-2_4
SP - 55
EP - 77
PB - Springer Nature
AN - OPUS4-52698
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Roszak, I.
A1 - Oswald, L.
A1 - Ouahabi, A. A.
A1 - Bertin, Annabelle
A1 - Laurent, E.
A1 - Felix, O.
A1 - Carvin-Sergent, I.
A1 - Charles, L.
A1 - Lutz, J.-F.
T1 - Synthesis and sequencing of informational poly(amino phosphodiester)s
N2 - Sequence-defined poly(amino phosphodiester)s containing main-chain tertiary amines were synthesized by automated solid-phase phosphoramidite chemistry. These polymers were prepared using four monomers with different substituents. The formed polymers were characterized by HPLC and mass spectrometry. These methods evidenced preparation of molecularly-defined polymers. Furthermore, the presence of tertiary amines in the polymer backbones facilitates sequencing by tandem mass spectrometry.
KW - Poly(amino phosphodiester)
KW - Synthesis
KW - HPLC
KW - Mass spectrometry
PY - 2021
DO - https://doi.org/10.1039/d1py01052b
SN - 1759-9954
VL - 12
IS - 37
SP - 5279
EP - 5282
PB - Royal Society of Chemistry
AN - OPUS4-53732
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zarinwall, A.
A1 - Waniek, Tassilo
A1 - Saadat, R.
A1 - Braun, U.
A1 - Sturm, Heinz
A1 - Garnweitner, G.
T1 - Comprehensive Characterization of APTES Surface Modifications of Hydrous Boehmite Nanoparticles
N2 - Hydrous boehmite (γ-AlOOH) nanoparticles (BNP) show great potential as nanoscale filler for the fabrication of fiber reinforced nanocomposite materials. Notably, the particle−matrix interaction has been demonstrated to be decisive for improving the matrix-dominant mechanical properties in the past years. Tailoring the surface properties of the nanofiller enables to selectively design the interaction and thus to exploit the benefits of the nanocomposite in an optimal way. Here, an extensive study is presented on the binding of (3-aminopropyl)triethoxysilane (APTES), a common silane surface modifier, on BNP in correlation to different process parameters (concentration, time, temperature, and pH). Furthermore, a comprehensive characterization of the modified BNP was performed by using elemental analysis (EA), thermogravimetric analysis (TGA) coupled with mass spectrometry (TGA-MS), and Kaiser’s test (KT). The results show an increasing monolayer formation up to a complete surface coverage with rising APTES concentration, time, and temperature, resulting in a maximal grafting density of 1.3 molecules/nm². Unspecific multilayer formation was solely observed under acidic conditions. Comparison of TGA-MS results with data recorded from EA, TGA, and KT verified that TGA-MS is a convenient and highly suitable method to elucidate the ligand binding in detail.
KW - Boehmite
KW - Nanoparticle
KW - Surface
KW - APTES
KW - Functionalization
KW - BET
KW - TGA
KW - Grafting
KW - Nanocomposite
KW - Silane
PY - 2020
DO - https://doi.org/10.1021/acs.langmuir.0c02682
VL - 37
IS - 1
SP - 171
EP - 179
PB - ACS Publications
AN - OPUS4-51954
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - RPRT
A1 - Hahn, Marc Benjamin
A1 - Sturm, Heinz
A1 - Bier, F
A1 - Solomun, Tihomir
T1 - Biologische Konsequenzen einer nanoskaligen Energiedeposition: Fokussierung auf die Rolle niederenergetischer Elektronen
T1 - Biological Consequence of Nanoscale Energy Deposition: Focusing on the Role of Low-Energy Electrons
N2 - Bei der Behandlung von Krebs mittels Strahlentherapie sollen Tumorzellen abgetötet werden ohne das umliegende gesunde Gewebe zu zerstören. Um Strahlentherapien für Patienten verträglicher zu machen, ist ein besseres Verständnis der zugrundeliegenden Prozesse auf der molekularen Ebene nötig. Dabei sind der Energieeintrag und die Streuprozesse der Strahlung in der Umgebung der DNA von besonderem Interesse. Durch Streuung von hochenergetischer Strahlung in Wasser werden besonders viele Sekundärelektronen mit niedriger Energie erzeugt. Zur Untersuchung der Schädigungseffizienz dieser Elektronen wurde ein Verfahren zur direkten Bestrahlung von Lösungen mittels Elektronen variabler Energien enwtickelt. Dies wurde durch einen neu entwickelten Probenhalter mit einer für Elektronen durchlässigen Nanomembran ermöglicht. Mit diesem können Bestrahlungen an DNA, Proteinen, und Zellen bei verschiedenen pH-Werten oder Salzkonzentrationen durchgeführt werden. Parallel dazu wurde der ortsabhängige Energieeintrag innerhalb des Wassers durch Elektronenstreusimulationen bestimmt. Diese neuartige Kombination von Experiment und Simulation ermöglicht die Bestimmung der Schaden-Dosis-Relation für Elektronenbestrahlung von biologischen Systemen unter realistischen physiologischen Bedingungen. So konnten für die genutzten Primärelektronen wie die mittlere letale Dosis, bei der 50 Prozent der DNA geschädigt sind, mit 1,7 Gy bestimmt. Ebenfalls wurde das für mikrodosimetrische Modellierungen und Betrachtungen der sogenannten Linear energy transfer (LET) Effekte, wichtige Verhältnis von DNA Einzelstrangbrüchen (SSB) zu Doppelstrangbrüchen (DSB) als SSB/DSB = 12/1 bestimmt. Mit Hilfe eines Modells für das Targetvolumen der DNA wurde der mittlere mikroskopische letale Energieeintrag berechnet als E1/2 = 6 ± 4 eV . Es wurde gefolgert, dass weniger als zwei Ionisationsprozesse im sensitiven Targetvolumen der DNA im Mittel zu einem Einzelstrangbruch führen. Diese Methode ist unabhängig von den Primärpartikel und geometrischen Bedingungen. Deshalb ermöglicht sie die Vergleichbarkeit experimenteller Systeme mit inhomogenen Energieverteilungen, welches sonst nicht gegeben ist. Des weiteren wurden die Strahlenschutzfunktionen des Zellschutzmoleküls Ectoines und sein Einfluss auf Wasser und Biomoleküle untersucht. Seine Schutzfunktion gegen ionisierende Strahlung wurde auf die Erhöhung des Streuquerschnitts niederenergetischer Elektronen und seine Eigenschaft als OH-Radikalfänger zurückgeführt. Aufbauend auf unseren Erkenntnissen finden in klinischen Arbeitsgruppen Untersuchungen zu Einsatzmöglichkeiten im Umfeld der Strahlentherapie statt.
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 245767821
N2 - To cure cancer radiation therapy is used to kill tumor cells. It is based on radiation induced damage to biomolecules. Here DNA damage is of key interest due to its central role in apoptosis and mutation. Because of the high amount of water in biological tissue, most of the damage is caused by the secondary particles produced by the inelastic scattering of ionizing radiation and water. A detailed understanding of the underlying molecular processes under physiological conditions is the prerequisite to develop more efficient the-rapies. Therefore irradiations have to be performed in liquid, under consideration of the chemical environment. To make it possible to irradiate liquids with electrons within scanning electron microscopes a new sample holder was constructed incorporating an electron transparent nanomembrane. It makes it possible to irradiate DNA, proteins or cells at different pH and salinity. The median lethal dose for a model system of plasmid DNA and water was determined by the combination of experimental data, particle scattering simulations (Geant4-DNA) and diffusion calculations as D1/2 = 1.7 ± 0.3 Gy. From the convolution of plasmid positions and the spatially resolved energy deposit, as determined by electron scattering simulations, the histogram of the energy deposit within the target volume of the plasmids and the microscopic median lethal energy deposit was calculated as E1/2 = 6 ± 4 eV . It could be deduced, that on average less than two ionization Events are sufficient to cause a single-strand-break. The relation of single-strand-breaks (SSB) to double-strand-breaks (DSB), which is of importance for microdosimetric modeling, was determined as SSB : DSB = 12 : 1. The presented method for the Determination of microscopic dose-damage relations was further extended to be applicable for General irradiation experiments. It is independent of the type of primary radiation used, the experimental geometry, and the diffusional properties of the molecules under investigation.
This way different experimental systems with varying, inhomogeneous energy deposit characteristics become comparable with each other, which is not possible when only macroscopic averaged values are taken into account. In addition, the radiation protection properties of the compatible solute Ectoine was investigated. The protective properties
of ectoine result from the increase of the inelastic scattering probabilities of low Energy electrons at the acoustic vibrational modes of water and its properties as OH-radical scavenger. Based on our results, further investigations are conducted to evaluate the
application of Ectoine in the context of radiation therapy.
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 245767821
KW - Ectoin
KW - Ectoine
KW - DNS
KW - DNA
KW - Cancer therapy
KW - DNA damage
KW - DNA radiation damage
KW - Dosimetry
KW - DFG
KW - Electron irradiation
KW - Ectoine DNA interaction
KW - Ectoine radiation protection
KW - Hydroxyl radicals
KW - OH radicals
KW - LEE
KW - Low energy electrons
KW - Microdosimetry
KW - Radiation
KW - Geant4
KW - Geant4-DNA
KW - Radiation therapy
KW - LET
PY - 2021
UR - https://gepris.dfg.de/gepris/projekt/245767821/ergebnisse?context=projekt&task=showDetail&id=245767821&selectedSubTab=2&
SP - 1
EP - 14
AN - OPUS4-52389
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tavasolyzadeh, Zeynab
A1 - Tang, Peng
A1 - Hahn, Marc Benjamin
A1 - Hweidi, Gada
A1 - Nordholt, Niclas
A1 - Haag, Rainer
A1 - Sturm, Heinz
A1 - Topolniak, Ievgeniia
T1 - 2D and 3D Micropatterning of Mussel‐Inspired Functional Materials by Direct Laser Writing
N2 - AbstractThis work addresses the critical need for multifunctional materials and substrate‐independent high‐precision surface modification techniques that are essential for advancing microdevices and sensing elements. To overcome existing limitations, the versatility of mussel‐inspired materials (MIMs) is combined with state‐of‐the‐art multiphoton direct laser writing (DLW) microfabrication. In this way, 2D and 3D MIM microstructures of complex designs are demonstrated with sub‐micron to micron resolution and extensive post‐functionalization capabilities. This study includes polydopamine (PDA), mussel‐inspired linear, and dendritic polyglycerols (MI‐lPG and MI‐dPG), allowing their direct microstructure on the substrate of choice with the option to tailor the patterned topography and morphology in a controllable manner. The functionality potential of MIMs is demonstrated by successfully immobilizing and detecting single‐stranded DNA on MIM micropattern and nanoarray surfaces. In addition, easy modification of MIM microstructure with silver nanoparticles without the need of any reducing agent is shown. The methodology developed here enables the integration of MIMs in advanced applications where precise surface functionalization is essential.
KW - Direct laser writing
KW - Mussel-inspired materials
KW - Polyglycerol
KW - Polydopamine
KW - Micropatterning
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588778
DO - https://doi.org/10.1002/smll.202309394
SN - 1613-6829
SP - 1
EP - 12
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-58877
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Topolniak, Ievgeniia
A1 - Knigge, Xenia
A1 - Radnik, Jörg
A1 - Sturm, Heinz
T1 - Maskless Micropatterning of Polydopamine for versatile surface functionalization
N2 - Inspired by the chemistry of mussel adhesive proteins, polydopamine (PDA has been shown as one of the most versatile platforms for altering the properties and incorporating new functionalities to nearby any material surface despite its nature. Rich chemistry of PDA enables broad variety of surface modification and diverse secondary reactions that makes it extremely interesting for a wide range of application including biomedical field, e.g., drug delivery, adhesives, cell adhesion, biosensing. Despite high potential of polydopamine, the lack of deposition control and precision in existed methods limits their applications in microdevices and miniaturized functional systems like, for example, MEMS, microfluidic and sensorics.
Herein, we demonstrate a novel maskless approach for surface micropatterning with polydopamine based on Multiphoton Lithography that overcomes present limitations. Neither strong oxidants, metal ions nor adjustment of pH to alkaline is required by this technique. The spatial resolution down to 0.8 µm has been achieved which is at least an order of magnitude smaller than shown by other existed methods. We are able to control the morphology and thickness of the micropattern by altering fabrication parameters allowing structure gradient.
Apart from the glass substrate, we achieved PDA patterning at surfaces of different nature such as polychlorotrifluoroethylene, polydimethylsiloxane, polyethylene terephthalate, silicon wafers, and fluorinated glass coverslips. Post-modification of polydopamine micropatterns with protein enzyme like trypsin is demonstrated to highlight its sensing potential.
Presented in this work microfabrication technique empowers advanced applications of mussel-inspired materials in single-molecule bioassays, sensors and other complex microdevices.
T2 - International Conference on Precision Engineering and Sustainable Manufacturing
CY - Okinawa, Japan
DA - 18.07.2023
KW - Multiphoton lithography
KW - Polydopamine
KW - Micropatterning
PY - 2023
AN - OPUS4-58878
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Elert, Anna Maria
A1 - Chen, Yong-Cin
A1 - Smales, Glen Jacob
A1 - Topolniak, Ievgeniia
A1 - Sturm, Heinz
A1 - Schönhals, Andreas
A1 - Szymoniak, Paulina
T1 - Effects of the charge density of nanopapers based on carboxymethylated cellulose nanofibrils investigated by complementary techniques
N2 - Cellulose nanofibrils (CNFs) with different charge densities were prepared and investigated by a combination of different complementary techniques sensitive to the structure and molecular dynamics of the system. The morphology of the materials was investigated by scanning electron microscopy (SEM) and X-ray scattering (SAXS/WAXS). The latter measurements were quantitatively analyzed yielding to molecular parameters in dependence of the charge density like the diameter of the fibrils, the distance between the fibrils, and the dimension of bundles of nanofibrils, including pores. The influence of water on the properties and the charge density is studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and broadband dielectric spectroscopy. The TGA measurements reveal two mass loss processes. The one at lower temperatures was related to the loss of water, and the second process at higher temperatures was related to the chemical decomposition. The resulting char yield could be correlated to the distance between the microfibrils. The DSC investigation for hydrated CNFs revealed three glass transitions due to the cellulose segments surrounded by water molecules in different states. In the second heating scan, only one broad glass transition is observed. The dielectric spectra reveal two relaxation processes. At low temperatures or higher frequencies, the β-relaxation is observed, which is assigned to localized fluctuation of the glycosidic linkage. At higher temperatures and lower frequencies, the α-relaxation takes places. This relaxation is due to cooperative fluctuations in the cellulose segments. Both processes were quantitatively analyzed. The obtained parameters such as the relaxation rates were related to both the morphological data, the charge density, and the content of water for the first time.
KW - Cellulose nanofibrils
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600528
DO - https://doi.org/https://doi.org/10.1021/acsomega.4c00255
SN - 2470-1343
VL - 9
SP - 20152
EP - 20166
PB - ACS
AN - OPUS4-60052
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fritzsche, Sven
A1 - Pauw, Brian Richard
A1 - Weimann, Christiane
A1 - Sturm, Heinz
T1 - First of its kind: A test artifact for direct laser writing
N2 - With femtosecond-laser direct writing (fs-LDW) maturing in all aspects as a manufacturing technology, a toolset for quality assurance must be developed. In this work we introduce a first of its kind test artifact. Test artifacts are standardized 3D models with specific geometric features to evaluate the performance of writing parameters. Test artifacts are already common in other 3D additive manufacturing technologies e.g. selective laser melting. The test artifact introduced in this work was developed in particular to accommodate the high geometrical resolution of fs-LDW structures and the limited possibilities to examine the resulting structure. Geometric accuracy, surface adhesion as well as confocal Raman spectroscopy results were considered when evaluating the design of the test artifact. We will explain the individual features and design considerations of our fs-LDW test artifact. The difference between two slicers, Cura and 3DPoli, and the implications on measured feature sizes and the general shape is quantified. The measured geometries are used to derive a general design guide for a specific combination of photoresists, laser power and scanning speed and to analyze the geometric accuracy of a structure produced using these guidelines. The shown test artifact is publicly available as STL file on GitHub (https://github.com/BAMresearch/2PP-TestArtifact) and in the supplement.
KW - Laser direct writing
KW - Multi photon lithography
KW - Reference material
KW - Raman spectroscopy
KW - Confocal raman imaging
KW - Slicers
KW - Open data on zenodo
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580951
DO - https://doi.org/10.1088/1361-6501/acc47a
VL - 34
IS - 7
SP - 1
EP - 14
PB - IOP Science
AN - OPUS4-58095
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Silbernagl, Dorothee
A1 - Szymoniak, Paulina
A1 - Tavasolyzadeh, Zeynab
A1 - Sturm, Heinz
A1 - Topolniak, Ievgeniia
T1 - Multiphoton lithography of interpenetrating polymer networks for tailored microstructure thermal and micromechanical properties
N2 - Multiphoton lithography (MPL), an emerging truly 3D microfabrication technique, exhibits substantial potential in biomedical applications, including drug delivery and tissue engineering. Fabricated micro-objects are often expected to undergo shape morphing or bending of the entire structure or its parts. Furthermore, ensuring precise property tuning is detrimental to the realization of the functionality of MPL microstructures. Herein, novel MPL materials based on interpenetrating polymer networks (IPNs) are presented that effectively combine the advantages of acrylate and epoxy systems. IPNs with varying component ratios are investigated for their microfabrication performance and structural integrity with respect to thermal and micromechanical properties. A variety of high-resolution techniques is applied to comprehensively evaluate IPN properties at the bulk, micron, and segmental levels. This study shows that the MPL laser scanning velocity and power, photoinitiator content, and multi-step exposure can be used to tune the morphology and properties of the IPN. As a result, a library of 3D MPL IPN microstructures with high 3D structural stability and tailored thermal and micromechanical properties is achieved. New IPN microstructures with Young’s moduli of 3–4 MPa demonstrate high-to-fully elastic responses to deformations, making them promising for applications in morphable microsystems, soft micro-robotics, and cell engineering.
KW - Interpenetrating polymer network
KW - Multiphoton lithography
KW - Atomic force microscopy
KW - Intermodulation AFM
KW - Fast scanning calorimetry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600593
DO - https://doi.org/10.1002/smll.202310580
SN - 1613-6810
SP - 1
EP - 12
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-60059
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - George, Janine
T1 - Robust Data Generation, Heuristics and Machine Learning for Materials Design
N2 - This talk first introduces students to the Materials Acceleration Platforms and Advanced Materials Characterization at BAM. Then, it motivates high-throuhgput screening for materials discovery and advanced materials simulations based on these core topics. Then four different research studies are presentend: evaluation of generative models, synthesizability prediction via PU learning, acceleration of materials property predictions with bonding analysis and advanced materials simulations supported by automatically trained machine learning potentials.
T2 - Guest Lecture in MSE 403/1003, a Seminar in the Curriculum of the University of Toronto
CY - Online meeting
DA - 13.02.2026
KW - Automation
KW - Materials Acceleration Platforms
KW - Machine Learning
KW - Workflows
KW - Phonons
KW - Bonding Analysis
KW - Thermal Conductivity
PY - 2026
AN - OPUS4-65514
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 - CONF
A1 - Topolniak, Ievgeniia
A1 - Elert, Anna Maria
A1 - Knigge, Xenia
A1 - Cifci, G. C.
A1 - Radnik, Jörg
A1 - Sturm, Heinz
T1 - Polydopamine micropatterning for selective substrate bio-functionalization
N2 - Inspired by the chemistry of mussel adhesive proteins, polydopamine (PDA) exhibits strong adhesion to nearly any kind of organic or inorganic surface and shows high ability for surface post-modification and secondary reactions. As a result, PDA has been widely used as a base adlayer to enable versatile surface chemistry and functionalization. It has shown great potential in wide range of applications including biomedical field (e.g., drug delivery, adhesives, photothermal therapy, bone and tissue engineering, cell adhesion, biosensing). However, implementation of PDA in microdevices is still hindered by insufficient spatial and temporal control of excited deposition methods.
In this work we present a novel approach to fabricate tunable micropatterned substrates where mussel-inspired chemistry provides base for various surface modification [2]. Current approach applies Multiphoton Lithography (MPL) to initiate local PDA formation, and, therefore, does not require use of microstamp or photomask. As a result, the microstructures of complex designs can be produced with the spatial resolution down to 0.8 μm (Figure 1). The desired design can be easily altered by adjusting the stl model or the fabrication code. Unlike the conventional deposition of PDA based on dopamine auto-oxidation, our method does not require presence of strong oxidants, metal ions or alkaline pH. Herein-demonstrated deposition approach will significantly facilitate applications of polydopamine and other mussel-inspired materials in microdevices and high-resolution active microcomponents (e.g., in MEMS and microfluidics).
Adjustment of MPL parameters revealed that the morphology and thickness of resulted PDA microstructures can be controlled by altering the laser power and its scanning velocity. As a result, it also enables the production of micropatterns with structural gradient. Apart from the glass substrate, we performed PDA patterning at surfaces of different nature such as polychlorotrifluoroethylene, polydimethylsiloxane, polyethylene terephthalate, silicon wafers, and fluorinated glass coverslips. We tested different composition of dopamine solution for its ability of PDA buildup. Solutions containing Tris buffer, phosphate buffer or DI water only as well as different pH (6.0, 7.0 and 8.5) could be successfully applied for high-precision PDA micropatterning. Moreover, the effect of antioxidants and purging of the solution with oxygen and nitrogen was investigated. In all cases, no decrease of deposition efficiency was observed. The chemical nature of PDA was confirmed by locally recorded vibrational and x-ray photoelectron spectra. To ensure post-modification potential of MPL deposited PDA we demonstrated one-step deposition of micropatterns with trypsin. Obtained bio-functionalised surface can be further applied as a protein sensing active microelement.
T2 - Laser Precision Microfabrication
CY - Dresden, Germany
DA - 07.06.2022
KW - Polydopamine
KW - Two-photon polymerisation
KW - Micropatterning
PY - 2022
AN - OPUS4-55064
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Fritzsche, Sven
T1 - Classification of defects in Direct Laser Writing
N2 - Direct laser writing grows to an industry-ready manufacturing platform. A stable quality infrastructure is needed for robust processing. However, flaws, errors or impurities are neither described nor communicated in the community of two-photon polymerization.
In contrast, additive manufacturing errors in metals manufacturing are described thoroughly.
T2 - MNE EUROSENSORS 2022
CY - Leuven, Belgium
DA - 19.09.2022
KW - Quality infrastructure
KW - Direct laser writing
KW - Two photon polymerisation
PY - 2022
AN - OPUS4-55984
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fortini, Renata
A1 - Meyer-Plath, A.
A1 - Kehren, D.
A1 - Gernert, U.
A1 - Agudo Jácome, Leonardo
A1 - Sturm, Heinz
T1 - Measurement of flexural rigidity of multi-walled carbon nanotubes by Dynamic Scanning Electron Microscopy
N2 - In this work the flexural rigidity of individual large diameter multi-walled carbon nanotubes (MWCNTs) was investigated. The bending modulus were obtained by detecting the resonance frequencies of mechanically excited cantilevered carbon nanotubes using the so-called dynamic scanning electron microscopy technique, and applying the Euler–Bernoulli beam theory. For the nanotubes studied, we determined a modulus of up to 160 GPa. This agrees with values reported by other authors for MWCNTs produced by catalytic chemical vapor deposition, however, it is 6-8 times smaller than values reported for single and multi-walled carbon nanotubes produced by arc-discharge synthesis. Toxicological studies with carbon nanotubes have been showing that inhaled airborne nanofibers that reach the deep airways of the respiratory system may lead to serious, asbestos-like lung diseases. These studies suggested that their toxicity critically depends on the fiber flexural rigidity, with high rigidity causing cell lesions. To complement the correlation between observed toxicological effects and fiber rigidities, reliable and routinely applicable measurement techniques for the flexural rigidity of nanofibers are required.
KW - Flexural rigidity
KW - Bending modulus
KW - Resonance frequency
KW - Carbon nanotubes
KW - Fiber toxicology
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514190
DO - https://doi.org/10.3390/fib8050031
SN - 2079-6439
VL - 8
IS - 5
SP - 31
PB - MDPI
AN - OPUS4-51419
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Silbernagl, Dorothee
A1 - Ghasem Zadeh Khorasani, Media
A1 - Cano Murillo, Natalia
A1 - Elert, Anna Maria
A1 - Sturm, Heinz
ED - Glatzel, T.
T1 - Bulk chemical composition contrast from attractive forces in AFM force spectroscopy
N2 - A key application of atomic force microscopy (AFM) is the measurement of physical properties at sub-micrometer resolution. Methods such as force–distance curves (FDCs) or dynamic variants (such as intermodulation AFM (ImAFM)) are able to measure mechanical properties (such as the local stiffness, kr) of nanoscopic heterogeneous materials. For a complete structure–property correlation, these mechanical measurements are considered to lack the ability to identify the chemical structure of the materials. In this study, the measured attractive force, Fattr, acting between the AFM tip and the sample is shown to be an independent measurement for the local chemical composition and hence a complete structure–property correlation can be obtained. A proof of concept is provided by two model samples comprised of (1) epoxy/polycarbonate and (2) epoxy/boehmite. The preparation of the model samples allowed for the assignment of material phases based on AFM topography. Additional chemical characterization on the nanoscale is performed by an AFM/infrared-spectroscopy hybrid method. Mechanical properties (kr) and attractive forces (Fattr) are calculated and a structure–property correlation is obtained by a manual principle component analysis (mPCA) from a kr/Fattr diagram. A third sample comprised of (3) epoxy/polycarbonate/boehmite is measured by ImAFM. The measurement of a 2 × 2 µm cross section yields 128 × 128 force curves which are successfully evaluated by a kr/Fattr diagram and the nanoscopic heterogeneity of the sample is determined.
KW - AFM force spectroscopy
KW - Composites
KW - Principle component analysis
KW - Structure–property correlation
KW - Van der Waals forces
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520175
DO - https://doi.org/10.3762/bjnano.12.5
SN - 2190-4286
VL - 12
IS - 5
SP - 58
EP - 71
PB - Beilstein Institute
CY - Frankfurt am Main
AN - OPUS4-52017
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cano Murillo, Natalia
A1 - Ghasem Zadeh Khorasani, Media
A1 - Silbernagl, Dorothee
A1 - Hahn, Marc Benjamin
A1 - Hodoroaba, Vasile-Dan
A1 - Sturm, Heinz
T1 - Nanomechanical study of polycarbonate/boehmite nanoparticles/epoxy ternary composite and their interphases
N2 - Thermoplastic modified thermosets are of great interest especially due to their improved fracture toughness. Comparable enhancements have been achieved by adding different nanofillers including inorganic particles such as nanosized boehmite. Here, we present a nanomechanical study of two composite systems, the first comprising a polycarbonate (PC) layer in contact with epoxy resin (EP) and the second consisting of a PC layer containing boehmite nanoparticles (BNP) which is also in contact with an EP layer. The interaction between PC and EP monomer is tested by in situ Fourier transformed infrared (FT-IR) analysis, from which a reaction induced phase separation of the PC phase is inferred. Both systems are explored by atomic force microscopy (AFM) force spectroscopy. AFM force-distance curves (FDC) show no alteration of the mechanical properties of EP at the interface to PC. However, when a PC phase loaded with BNP is put in contact with an epoxy system during curing, a considerable mechanical improvement exceeding the rule of mixture was detected.
The trend of BNP to agglomerate preferentially around EP dominated regions and the stiffening effect of BNP on EP shown by spatial resolved measurements of Young's modulus, suggest the effective presence of BNP within the EP phase.
KW - Composites
KW - Mechanical properties
KW - Nanoparticles
KW - Thermoplastics
KW - Thermosets
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515965
DO - https://doi.org/10.1002/app.50231
SN - 0021-8995
SN - 1097-4628
VL - 138
IS - 12
SP - 1
EP - 11
PB - Wiley
CY - New York, NY
AN - OPUS4-51596
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sänger, Johanna Christiane
A1 - Pauw, Brian Richard
A1 - Sturm, Heinz
A1 - Günster, Jens
T1 - First time additively manufactured advanced ceramics by using two-photon polymerization for powder processing
N2 - Methods and materials are presented here, which enable the manufacturing of fine structures using a 3D-printing method known as two-photon polymerization (2PP). As traditional photolithography methods for structuring ceramic slurries do not function with 2PP, due to light scattering on ceramic particles, a novel water-based photoresist with high ceramic loading of extremely well dispersed ceramic nano particles was developed. This photoresist is basically a ceramic slurry containing a photocurable agent and a photoinitiator to be crosslinkable with the 780 nm wavelength femtosecond laser light source of the 2PP machine. It is demonstrated that it is possible to gain a highly transparent and low viscous slurry suitable for 2PP processing. This work shows the development of the slurry, first printing results and the post-printing processes required to form three dimensional ceramic microstructures consisting of alumina toughened zirconia (ATZ).
KW - 3D-printing
KW - Two-photon polymerization
KW - 2PP
KW - Ceramic nano particles
KW - Slurry
KW - Alumina toughened zirconia
KW - ATZ
KW - Additive manufacturing
KW - SchwarzP cells
KW - Nano-ceramic-additive-manufacturing photoresin
KW - NanoCAM
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517441
DO - https://doi.org/10.1016/j.oceram.2020.100040
VL - 4
SP - 100040
PB - Elsevier Ltd.
AN - OPUS4-51744
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cano Murillo, Natalia
A1 - Ghasem Zadeh Khorasani, Media
A1 - Silbernagl, Dorothee
A1 - Emamverdi, Farnaz
A1 - Cacua, K.
A1 - Hodoroaba, Vasile-Dan
A1 - Sturm, Heinz
T1 - Carrier Fibers for the Safe Dosage of Nanoparticles in Nanocomposites: Nanomechanical and Thermomechanical Study on Polycarbonate/Boehmite Electrospun Fibers Embedded in Epoxy Resin
N2 - The reinforcing effect of boehmite nanoparticles (BNP) in epoxy resins for fiber composite lightweight construction is related to the formation of a soft but bound interphase between filler and polymer. The interphase is able to dissipate crack propagation energy and consequently increases the fracture toughness of the epoxy resin. Usually, the nanoparticles are dispersed in the resin and then mixed with the hardener to form an applicable mixture to impregnate the fibers. If one wishes to locally increase the fracture toughness at particularly stressed positions of the fiber-reinforced polymer composites (FRPC), this could be done by spraying nanoparticles from a suspension. However, this would entail high costs for removing the nanoparticles from the ambient air. We propose that a fiber fleece containing bound nanoparticles be inserted at exposed locations. For the present proof-of-concept study, an electrospun polycarbonate nonwoven and taurine modified BNP are proposed. After fabrication of suitable PC/EP/BNP composites, the thermomechanical properties were tested by dynamic mechanical analysis (DMA). Comparatively, the local nanomechanical properties such as stiffness and elastic modulus were determined by atomic force microscopy (AFM). An additional investigation of the distribution of the nanoparticles in the epoxy matrix, which is a prerequisite for an effective nanocomposite, is carried out by scanning electron microscopy in transmission mode (TSEM). From the results it can be concluded that the concept of carrier fibers for nanoparticles is viable.
KW - Advanced materials
KW - Electrospun nanocomposite fiber
KW - Nanomechanical charecteisation
KW - Nanosafety
KW - Epoxy nanocomposites
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528265
DO - https://doi.org/10.3390/nano11061591
VL - 11
IS - 6
SP - 1591
PB - MDPI
CY - CH - 4020 Basel, Switzerland
AN - OPUS4-52826
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Waniek, Tassilo
A1 - Braun, U.
A1 - Silbernagl, Dorothee
A1 - Sturm, Heinz
T1 - The impact of water released from boehmite nanoparticles during curing in epoxy-based nanocomposites
N2 - The enhancing effect on mechanical properties of boehmite (γ-AlOOH) nanoparticles (BNP) in epoxy-based nanocomposites on the macroscopic scale encouraged recent research to investigate the micro- and nanoscopic properties. Several studies presented different aspects relatable to an alteration of the epoxy polymer network formation by the BNP with need for further experiments to identify the mode of action.
With FTIR-spectroscopic methods this study identifies interactions of the BNP with the epoxy polymer matrix during the curing process as well as in the cured nanocomposite. The data reveals that not the BNP themselves, but the water released from them strongly influences the curing process by hydrolysis of the anhydride hardener or protonation of the amine accelerator. The changes of the curing processes are discussed in detail.
The changes of the curing processes enable new explanation for the changed material properties by BNP discussed in recent research like a lowered glass transition temperature region (Tg) and an interphase formation.
KW - Spectroscopy
KW - Aluminium oxide hydroxide
KW - Glass transition temperature
KW - Material chemistry
KW - Nanocomposites
KW - Structure-property relationship
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527202
DO - https://doi.org/10.1002/app.51006
VL - 138
IS - 39
SP - 51006
PB - Wiley Periodicals LLC
CY - Hoboken
AN - OPUS4-52720
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fritzsche, Sven
A1 - Topolniak, Ievgeniia
A1 - Weise, Matthias
A1 - Sturm, Heinz
T1 - Shape deviations of DLW microstructures in dependency of fabrication parameters
N2 - Deep understanding of the effects associated with fabrication parameters and their influence on the resulting structures shape is essential for the further development of direct laser writing (DLW). In particular, it is critical for development of reference materials, where structure parameters are precisely fabricated and should be reproduced with use of DLW technology. In this study we investigated the effect of various fabrication and preparation parameters on the structural precision of interest for reference materials. A well-studied photo-curable system, SZ2080 negative photo-resist with 1 wt.% Michler's ketone (Bis) photo-initiator, was investigated in this work. The correlation between applied laser power, laser velocity, fabrication direction on the deviations in the structure shape were observed by means of white light interferometry microscopy. Moreover, influence of slicing and hatching distances as well as prebake time were studied as function of sample shape. Deviations in the structure form between the theoretically expected and the one detected after DLW fabrication were observed in the range up to 15%. The observed shape discrepancies show the essential importance of fine-tuning the fabrication parameter for reference structure production.
KW - Direct laser writing
KW - Fabrication parameters
KW - Structural precision
KW - SZ2080 negative photo-resist
KW - White light interferometry microscopy
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535906
DO - https://doi.org/10.1088/1361-6439/ac2a14
VL - 31
IS - 12
SP - 1
EP - 8
PB - IOP Science
AN - OPUS4-53590
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zou, T.
A1 - Nonappa, N.
A1 - Khavani, M.
A1 - Vuorte, M.
A1 - Penttilä, P.
A1 - Zitting, A.
A1 - Valle-Delgado, J. J.
A1 - Elert, Anna Maria
A1 - Silbernagl, Dorothee
A1 - Balakshin, M.
A1 - Sammalkorpi, M.
A1 - Österberg, M.
T1 - Experimental and Simulation Study of the Solvent Effects on the Intrinsic Properties of Spherical Lignin Nanoparticles
N2 - Spherical lignin nanoparticles (LNPs) fabricated via nanoprecipitation of dissolved lignin are among the most attractive biomass-derived nanomaterials. Despite various studies exploring the methods to improve the uniformity of LNPs or seeking more application opportunities for LNPs, little attention has been given to the fundamental aspects of the solvent effects on the intrinsic properties of LNPs. In this study, we employed a variety of experimental techniques and molecular dynamics (MD) simulations to investigate the solvent effects on the intrinsic properties of LNPs. The LNPs were prepared from softwood Kraft lignin (SKL) using the binary solvents of aqueous acetone or aqueous tetrahydrofuran (THF) via nanoprecipitation. The internal morphology, porosity, and mechanical properties of the LNPs were analyzed with electron tomography (ET), small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), and intermodulation AFM (ImAFM). We found that aqueous acetone resulted in smaller LNPs with higher uniformity compared to aqueous THF, mainly ascribing to stronger solvent−lignin interactions as suggested by MD simulation results and confirmed with aqueous 1,4-dioxane (DXN) and aqueous dimethyl sulfoxide (DMSO).
More importantly, we report that both LNPs were compact particles with relatively homogeneous density distribution and very low porosity in the internal structure. The stiffness of the particles was independent of the size, and the Young’s modulus was in the range of 0.3−4 GPa. Overall, the fundamental understandings of LNPs gained in this study are essential for the design of LNPs with optimal performance in applications.
KW - Lignin
KW - Electron tomography
KW - Intermodulation AFM
KW - Modulus
KW - SAXS
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546948
DO - https://doi.org/10.1021/acs.jpcb.1c05319
SN - 1520-5207
VL - 125
IS - 44
SP - 12315
EP - 12328
PB - ACS
AN - OPUS4-54694
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lackmann, C.
A1 - Velki, M.
A1 - Šimić, A.
A1 - Müller, Axel
A1 - Braun, U.
A1 - Ečimović, S.
A1 - Hollert, H.
T1 - Two types of microplastics (polystyrene-HBCD and car tire abrasion) affect oxidative stress-related biomarkers in earthworm Eisenia andrei in a time-dependent manner
N2 - Microplastics are small plastic fragments that are widely distributed in marine and terrestrial environments. While the soil ecosystem represents a large reservoir for plastic, research so far has focused mainly on the impact on aquatic ecosystems and there is a lack of information on the potentially adverse effects of microplastics on soil biota. Earthworms are key organisms of the soil ecosystem and are due to their crucial role in soil quality and fertility a suitable and popular model organism in soil ecotoxicology.
Therefore, the aim of this study was to gain insight into the effects of environmentally relevant concentrations of microplastics on the earthworm Eisenia andrei on multiple levels of biological organization after different exposure periods. Earthworms were exposed to two types of microplastics: (1) polystyrene-HBCD and (2) car tire abrasion in natural soil for 2, 7, 14 and 28 d. Acute and chronic toxicity and all subcellular investigations were conducted for all exposure times, avoidance behavior assessed after 48 h and reproduction after 28 d. Subcellular endpoints included enzymatic biomarker responses, namely, carboxylesterase, glutathione peroxidase, acetylcholinesterase, glutathione reductase, glutathione S-transferase and catalase activities, as well as fluorescence-based measurements of oxidative stress-related markers and multixenobiotic resistance activity. Multiple biomarkers showed significant changes in activity, but a recovery of most enzymatic activities could be observed after 28 d. Overall, only minor effects could be observed on a subcellular level, showing that in this exposure scenario with environmentally relevant concentrations based on German pollution levels the threat to soil biota is minimal. However, in areas with higher concentrations of microplastics in the environment, these results can be interpreted as an early warning signal for more adverse effects. In conclusion, these findings provide new insights regarding the ecotoxicological effects of environmentally relevant concentrations of microplastics on soil organisms.
KW - Microplastics
KW - Earthworms
KW - Toxicity
KW - Biomarker
KW - oxidative stress
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545423
DO - https://doi.org/10.1016/j.envint.2022.107190
VL - 163
SP - 1
EP - 12
PB - Elsevier Ltd.
AN - OPUS4-54542
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - INPR
A1 - Fritzsche, Sven
A1 - Pauw, Brian Richard
A1 - Weimann, Christiane
A1 - Sturm, Heinz
T1 - First of its kind: A test artifact for direct laser writing
N2 - With Direct Laser Writing (DLW) maturing in all aspects as a manufacturing technology a toolset for quality assurance must be developed. In this work we want to introduce a first of its kind test artifact. Test artifacts are standardized 3D models with specific geometric feature to evaluate the performance of writing parameters. Test artifacts are already common in other 3D additive manufacturing technologies e.g. Selective Laser Melting. The test artifact introduced in this work was developed in particular to accommodate 1) the high geometrical resolution of DLW structures and 2) the limited possibilities to examine the resulting structure. Geometric accuracy, surface adhesion as well as confocal raman spectroscopy results were considered when evaluating the design of the test artifact. We will explain the individual features and design considerations of our DLW test artifact. The difference between two slicers, Cura and 3DPoli, and the implications on measured feature sizes and the general shape is quantified. The measured geometries are used to derive a general design guide for a specific combination of photoresist, laser power and scanning speed and to analyse the geometric accuracy of a structure produced using these guidelines.
KW - Multi photon lithography
KW - Test artifact
KW - Two photon polymerization
KW - Direct Laser Writing
KW - Quality infrastructure
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560530
DO - https://doi.org/10.20944/preprints202210.0259.v1
SP - 1
EP - 29
PB - MDPI
CY - Basel
AN - OPUS4-56053
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Silbernagl, Dorothee
A1 - Sturm, Heinz
A1 - Plajer, A. J.
T1 - Thioanhydride/isothiocyanate/epoxide ring-opening terpolymerisation: sequence selective enchainment of monomer mixtures and switchable catalysis
N2 - We report a new sequence selective terpolymerisation in which three monomers (butylene oxide (BO) A, PhNCS B and phtalic thioanhydride (PTA) C) are selectively enchained into an (ABA′C)n sequence. PTA/PhNCS/BO ring-opening terpolymerisation ROTERP can be coupled with CS2 ROTERP to generate tetrapolymers and with εDL ROP in switchable catalysis for blockpolymer synthesis.
KW - Blockcopolymer
KW - 1H-NMR
KW - TGA
KW - DSC
KW - AFM
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552339
DO - https://doi.org/10.1039/d2py00629d
SP - 1
EP - 5
PB - Royal Society of Chemistry
CY - Cambridge, UK
AN - OPUS4-55233
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - Near-ambient-pressure Xray photoelectron spectroscopy (XPS) to monitor DNA radiation damage directly in water
N2 - Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
T2 - RADeleven
CY - Herceg Novi, Montenegro
DA - 19.06.2023
KW - Base damage
KW - Base loss
KW - Cancer treatment
KW - DNA
KW - DNA radiation damage
KW - Direct damage
KW - Dissociative electron attachment (DEA)
KW - Dissociative electron transfer (DET)
KW - Dosimetry
KW - Double-strand break (DSB)
KW - ESCA
KW - Energy deposit
KW - Geant4
KW - Geant4-DNA
KW - Hydrated DNA
KW - Hydrated electron
KW - Hydrated electrons
KW - Hydration shell
KW - Hydroxyl radical
KW - Indirect damage
KW - Ionisation
KW - Ionization
KW - LEE
KW - DEA
KW - DET
KW - Low energy electrons
KW - MCS
KW - Microdosimetry
KW - NAP-XPS
KW - Near ambient pressure xray photo electron spectroscopy
KW - Net-ionization reaction
KW - OH radical
KW - PES
KW - Particle scattering
KW - Prehydrated electron
KW - Presolvated electron
KW - Protein
KW - Quasi-direct damage
KW - ROS
KW - Radiation damage
KW - Radiation therapy
KW - Radical
KW - Radiolysis
KW - Radiotherapy
KW - Reactive oxygen species
KW - Simulation
KW - Single-strand break (SSB)
KW - Single-stranded DNA-binding proteins
KW - TOPAS
KW - TOPAS-nbio
KW - XPS
KW - Xray photo electron spectrocopy
PY - 2023
AN - OPUS4-57782
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gawek, Marcel
A1 - Madkour, Sherif
A1 - Szymoniak, Paulina
A1 - Radnik, Jörg
A1 - Schönhals, Andreas
T1 - Energy Dependent XPS Measurements on Thin Films of a Poly(vinyl methyl ether)/Polystyrene Blend in Dependence on Film Thickness – Concentration Profile on a Nanometer Resolution to Understand the Behavior of Nanofilms
N2 - The composition of the surface layer in dependence from the distance of the polymer/air interface in thin films with thicknesses below 100 nm of miscible polymer blends in a spatial region of a few nanometers is not investigated completely. Here, thin films of the blend poly vinyl methyl ether) (PVME)/polystyrene (PS) with a composition of 25/75 wt% are investigated by Energy Resolved X-ray Photoelectron Spectroscopy (ER-XPS) at a synchrotron storage ring using excitation energies lower than 1 keV. By changing the energy of the photons the information depth is varied in the range from ca. 1 nm to 10 nm. Therefore, the PVME concentration could be estimated in dependence from the distance of the polymer/air interface for film thicknesses below 100 nm. Firstly, as expected for increasing information depth the PVME concentration decreases. Secondly, it was found that the PVME concentration at the surface has a complicated dependence on the film thickness. It increases with decreasing film thickness until 30 nm where a maximum is reached. For smaller film thicknesses the PVME concentration decreases. A simplified layer model is used to calculate the effective PVME concentration in the different spatial regions of the surface layer.
KW - Energy dependent XPS
KW - Soft X-ray
KW - Thin films
PY - 2021
DO - https://doi.org/10.1039/d1sm00656h
VL - 17
IS - 29
SP - 6985
EP - 6994
PB - The Royal Chemical Society
AN - OPUS4-53039
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radnik, Jörg
T1 - Energy-resolved x-ray photoelectron spectroscopy measurements on the concentration profile of thin blended poly(vinyl methyl ether)/polystyrene films
N2 - The composition of thin films of polymer blends in vertical direction is still under discussion. For explaining the thickness dependence of some properties like the thermal glass transition temperature, a three-layer model has been introduced consisting of an adsorbed layer with a reduced segmental mobility at the substrate, a bulk-like layer in the middle of the film and an outermost surface layer with a higher molecular mobility. X-ray photoelectron spectroscopy (ER-XPS) measurements with a varying excitation energy from 400 eV to 1486.6 eV and, herewith, an information depth from 1.5 nm to 10 nm were performed at PVME/PS films with compositions of 25/75 wt% and 50/50 wt% and thicknesses between 15 nm and 190 nm. As expected, it was found that the PVME concentration decreases with increasing information depth. Secondly, a complex correlation between the PVME concentration at the surface and the film thickness was found. The PVME concentration increases with decreasing film thickness until a maximum at 30 nm. For thinner films, the PVME concentration decreases. These data agree with previous investigations obtained with specific heat spectroscopy.
We thank BESSY II (HZB) for the allocation of beamtime at the HE-SGM beamline and for technical support. DFG (Project number 124846229) is acknowledged for financial support.
T2 - German Conference for Research with Synchrotron Radiation, Neutrons and Ion Beams at Large Facilities (SNI2022)
CY - Berlin, Germany
DA - 05.09.2022
KW - X-ray photoelectron spectroscopy
KW - Miscible polymer films
KW - Depth profiling
PY - 2022
AN - OPUS4-55654
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - The change of DNA AND PROTEIN radiation damage upon hydration: In-situ observations by near-ambient-pressure XPS
N2 - X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. Our results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
T2 - Dyson Conference 2023
CY - Prague, Czech Republic
DA - 24.04.2023
KW - Base damage
KW - Base loss
KW - Cancer treatment
KW - DNA
KW - DNA radiation damage
KW - Direct damage
KW - Dissociative electron attachment (DEA)
KW - Dissociative electron transfer (DET)
KW - Dosimetry
KW - Double-strand break (DSB)
KW - ESCA
KW - Energy deposit
KW - Geant4
KW - Geant4-DNA
KW - Hydrated DNA
KW - Hydrated electron
KW - Hydration shell
KW - Hydroxyl radical
KW - Indirect damage
KW - Ionization
KW - Ionisation
KW - LEE
KW - Low energy electrons
KW - MCS
KW - Microdosimetry
KW - NAP-XPS
KW - Near ambient pressure xray photo electron spectroscopy
KW - Net-ionization reaction
KW - OH radical
KW - PES
KW - Particle scattering
KW - Prehydrated electron
KW - Presolvated electron
KW - Quasi-direct damage
KW - ROS
KW - Radiation damage
KW - Radiation therapy
KW - Radical
KW - Radiolysis
KW - Radiotherapy
KW - Reactive oxygen species
KW - Simulation
KW - Single-strand break (SSB)
KW - TOPAS
KW - TOPAS-nbio
KW - XPS
KW - Xray
KW - Xray photo electron spectrocopy
KW - G5P
KW - Protein
KW - Single-stranded DNA-binding proteins
PY - 2023
AN - OPUS4-57406
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hallier, Dorothea C.
T1 - An XPS study on X-ray radiation damage: Chemical changes to Gene-V Protein of Bacteriophage M13
N2 - X-ray photoelectron spectroscopy (XPS) is used to analyze the direct damage of ionizing radiation to a single-stranded DNA binding protein: Gene-V Protein (G5P).
T2 - Science Day Uni Potsdam Institut für Biochemie und Biologie
CY - Potsdam, Germany
DA - 11.10.2022
KW - XPS
KW - Radiaton damage
KW - G5P GVP
KW - Single-stranded DNA-binding protein
KW - X-ray
KW - DNA
PY - 2022
AN - OPUS4-56541
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - The change of DNA radiation damage upon hydration: In-situ observations by near-ambient-pressure XPS
N2 - Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
T2 - #RSCposter 2023
CY - Online meeting
DA - 28.02.2023
KW - Cancer treatment
KW - DNA
KW - Dosimetry
KW - Energy deposit
KW - Geant4
KW - Geant4-DNA
KW - TOPAS
KW - TOPAS-nbio
KW - particle scattering
KW - Simulation
KW - Radiolysis
KW - Radiation therapy
KW - Radiotherapy
KW - LEE
KW - Low energy electrons
KW - MCS
KW - Base damage
KW - Base loss
KW - DNA radiation damage
KW - Direct damage
KW - Dissociative electron transfer (DET)
KW - Dissociative electron attachment (DEA)
KW - Double-strand break (DSB)
KW - Hydrated DNA
KW - Hydrated electron
KW - Ionization
KW - Hydration shell
KW - Hydroxyl radical
KW - Indirect damage
KW - Microdosimetry
KW - NAP-XPS
KW - Near ambient pressure xray photo electron spectroscopy
KW - Net-ionization reaction
KW - OH radical
KW - PES
KW - Prehydrated electron
KW - Quasi-direct damage
KW - Radiation damage
KW - Radical
KW - Reactive oxygen species
KW - ROS
KW - Single-strand break (SSB)
KW - XPS
KW - Xray
KW - Xray photo electron spectrocopy
KW - presolvated electron
PY - 2023
UR - https://www.nature.com/articles/s42004-021-00487-1
AN - OPUS4-57063
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - The change of dna and protein radiation damage upon hydration: in-situ observations by near-ambient-pressure xps
N2 - X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. Our results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further. Furthermore, first data about the degradation of single-stranded DNA binding-proteins (G5P / GV5 and hmtSSB) under vacuum and NAP-XPS conditions are presented.
T2 - AVS69
CY - Portland, USA
DA - 05.11.2023
KW - Base damage
KW - Base loss
KW - Cancer treatment
KW - DNA
KW - Protein
KW - Proteins
KW - Geant4
KW - Dosimetry
KW - Microdosimetry
KW - NAP-XPS
KW - Xray photo electron spectrocopy
KW - Radiation damage
KW - Geant4-DNA
KW - G5P
KW - GVP
KW - Hydroxyl radical
KW - LEE
KW - DEA
KW - DET
KW - ROS
KW - Prehydrated electron
KW - TOPAS
KW - Near ambient pressure xray photo electron spectroscopy
KW - SSB
KW - DSB
KW - Single-strand break (SSB)
KW - ESCA
KW - Single-stranded DNA-binding proteins
KW - Reactive oxygen species
PY - 2023
AN - OPUS4-58761
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Altmann, Korinna
T1 - Preliminary results of an interlaboratory comparison on microplastics organised by plasticsfate
N2 - Microplastics are everywhere in the environment, but analytics is challenging. Since harmonisation is missing as well es suitable reference materials, BAM did under th umbrella of VAMAS funded by the EU Horizon 2020 project PlasticsFate a ILC for microplastic detection methods. Methods adressed were IR, Raman, Py-GC/MS and TED-GC/MS. The talk gives a first presentation and evaluation on the results.
T2 - CUSP annual meeting and conference
CY - Utrecht, Netherlands
DA - 12.09.2023
KW - Microplastics
KW - TED-GC/MS
KW - Polymer 3R
KW - Reference material
KW - ILC on detection methods
PY - 2023
AN - OPUS4-60036
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Giovannozzi, A
T1 - Standardization and Harmonization Effort on Microplastics Analysis by Spectroscopic Methods
N2 - This talk presents the EU funded project PlasticTrace. It shows the challenges in micro- and nanoplastic reference materials and gives some solutions regarding spectroscipc methods such as Raman or IR microscopy to determine the particle numbers. Materials are prepared by cryo milling to get some powder that is later pressed into tablets. The polymer type used is PET, because that is highly important for drinking water directive of EU commission.
T2 - International Conference on Raman Spectroscopy (ICORS)
CY - Roma, Italy
DA - 28.07.2024
KW - Microplastics
KW - Reference materials
KW - Polymer 3R
PY - 2024
AN - OPUS4-60881
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Miliūtė, Aistė
T1 - Structural evolution of ZrV2O7: supercell persistence revealing local and global structure duality
N2 - In the AM2O7 family of negative thermal expansion materials (NTE), evidence of supercell at room temperature was reported following the Völlenke et al. discovery of missed superlattice due to the apparent linearity of the M-O-M bond in GeP2O7. Korthuis et al. and Khosrovani et al. demonstrated it to be true for cubic ZrV2O7 as well. It was concluded that at room temperature, the structure consists of 27 'subcells' with bent M2O7 groups that appear to form a linear configuration due to refinement of averaged position. However, around 100 °C, the transition to the “parent” cell was reported, where the cell volume increases, and the M-O-M angles are constrained by the Pa-3 space group symmetry to be 180°.
We followed structural changes in the ZrV2O7 at high temperatures to demonstrate partial disorder within the crystal, local and global structural duality and supercell persistence at high temperatures. Total scattering measurements and Pair Distribution Function (PDF) analysis revealed that the experimental pattern cannot be fitted with the “parent structure” model, and only the 3×3×3 supercell model can correspond to local and global structures throughout the full 25-700 °C temperature range.
We also show how short and long-range order within the crystal changes when approaching the phase transition, which might indicate the existence of coherent structural domains that evolve between order and disorder with increasing temperature. We further hypothesize how this can be related to the negative thermal expansion mechanism and the interpretation of structure solutions presenting data from high-temperature X-ray absorption fine structure (XAFS) and Transmission Electron Microscopy (TEM) measurements.
T2 - 5th International Symposium on Negative Thermal Expansion and Related Materials (ISNTE-5)
CY - Porto, Portugal
DA - 29.07.2025
KW - NTE
KW - Ab initio
KW - PDF
KW - CSM
PY - 2025
AN - OPUS4-63874
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Miliūtė, Aistė
T1 - Theoretical and experimental development of negative thermal expansion material ZrV2O7
N2 - Zirconium vanadate (ZrV2O7) is a well-known negative thermal expansion (NTE) material which stands out for its remarkable isotropic unit cell contraction over a broad temperature range (130°C < T < 800°C). This enables the fabrication of composites where the overall expansion coefficient can be tailored to a specific negative, positive, or neutral value. Consequently, such composite materials are attractive for many device applications because they can compensate for damage caused by thermal expansion. They are relevant to optical systems, electronic and biomedical applications.
In this study, we implement ab-initio-based vibrational computations with partially treated anharmonicity (quasi-harmonic approximation (QHA), temperature-dependent effective harmonic potentials (TDEP)[5]) in combination with experimental methods to follow and rationalize the negative thermal expansion in this material, including the influence of the local structure disorder, microstructure, and defects. In analytical techniques that can provide structural information such as pair distribution function analysis (PDF), X-ray diffraction (XRD), and Extended X-ray Absorption Fine Structure (EXAFS), molecules and atoms are fit geometrically without consideration of atom interactions. Therefore, in combination with these methods, we also consider potential energy surfaces and conclude what structures are likely to form energetically in the full NTE temperature range, in addition to fitting experimental data geometrically. We also optimise experimentally fitted structures to their lowest energy configurations and re-generate comparative data to observe what differences would be visible experimentally.
T2 - XLVIII International Congress of Theoretical Chemists of Latin Expression
CY - Cartagena de Indias, Colombia
DA - 13.07.2025
KW - NTE
KW - Ab initio
KW - QHA
KW - TDEP
KW - anharmonicity
PY - 2025
AN - OPUS4-63873
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gawek, Marcel
A1 - Omar, Hassan
A1 - Szymoniak, Paulina
A1 - Schönhals, Andreas
T1 - Growth kinetics of the adsorbed layer of poly(2-vinylpyridine) - An indirect observation of desorption of polymers from substrates
N2 - The growth kinetics of the adsorbed layer of poly(2-vinylpiridine) on silicon oxide is studied using a leaching technique which is based on the Guiselin brushes approach. The adsorbed layer is grown from a 200 nm thick P2VP film for several annealing time periods at different annealing temperatures. Then the film is solvent-leached, and the height of the remaining adsorbed layer is measured by atomic force microscopy. At the lowest annealing temperature only a linear growth regime is observed, followed by a plateau. Here, the molecular mobility of segments is too low to allow for a logarithmic growth. At higher annealing temperatures, both linear and logarithmic growth regimes are observed, followed by a plateau. At even higher annealing temperatures, the growth kinetics of the adsorbed layer changes.
A linear growth followed by logarithmic growth kinetics is observed for short annealing time periods. For longer annealing time periods, an upturn of the growth kinetics is observed. At the highest annealing temperature, only a logarithmic growth regime is found. The change in the growth kinetics is discussed by an alteration in the structure of the adsorbed layer. Moreover, the interaction between the polymer segments and the substrate becomes weaker due to both enthalpic and entropic effects. Therefore, at high annealing temperatures the polymer segments might more easily desorb from the substrate.
KW - Ultra thin polymer films
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575423
DO - https://doi.org/10.1039/d3sm00129f
SN - 1744-683X
SN - 1744-6848
VL - 19
IS - 21
SP - 3975
EP - 3982
PB - Royal Society of Chemistry (RSC)
CY - London
AN - OPUS4-57542
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Ueltzen, Katharina
A1 - Naik, Aakash
A1 - Ertural, Christina
A1 - Benner, Philipp
A1 - George, Janine
T1 - Software and data repository: Can simple exchange heuristics guide us in predicting magnetic properties of solids?
N2 - Software and data for the publication "Can simple exchange heuristics guide us in predicting magnetic properties of solids?" Release that corresponds to the first preprint version of the article. Full Changelog: https://github.com/DigiMatChem/paper-exchange-heuristics-in-magnetic-materials/commits/v1.0.0
KW - Magnetism
KW - Machine Learning
KW - Materials Design
KW - Chemically Complex Materials
KW - Sustainable Materials Design
PY - 2025
DO - https://doi.org/10.5281/zenodo.16811104
PB - Zenodo
CY - Geneva
AN - OPUS4-64672
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - BOOK
A1 - Schönhals, Andreas
A1 - Szymoniak, Paulina
T1 - Dynamics of Composite Materials
N2 - Historically, to tune the properties of a polymer or more general soft matter systems by a second phase is not a new concept and dates back to the 40s of the last century. Beside some successes, the improvement of the properties remained somehow limited. The expectations of the enhancement of the properties of composites changed by the developments of Toyota Central research in the 1990s. It was shown that the incorporation of 5 vol% exfoliated layers of a clay system into a polymer leads to a strong improvement of the mechanical and thermal properties. This discovery stimulated a broad research interest of both fundamental and applied character. Today, polymer-based nanocomposites have reached a billion-dollar global market. The corresponding applications span from components for transportation, commodity plastics with enhanced barrier and/or flame retardancy characteristics, to polymers with electrical properties for shielding, electronics, sensors, and solar cells as well as to live science. Important fields are filled rubbers, reinforced thermoplastics, or thermosets for automotive, aircraft/space and marine industries, but also membranes for separation processes as well as barrier layers, just to mention a few.
For a variety of applications, the molecular mobility in nanocomposites is of great importance. This concerns the molecular mobility needed to form a percolating filler network in rubbers used in tires or in composites employed in electric shielding applications. In general, it is also essential for processing polymer-based nanocomposites. Furthermore, separation processes in composite materials for membranes require a certain molecular mobility. This also concern nanodielectrics used in electrical applications or sensors where the mobility of charge carriers can be related to the fluctuations of molecular groups etc. Finally, the molecular mobility can be taken as probe for structure on a molecular scale.
Broadband dielectric spectroscopy is a powerful tool to investigate the molecular mobility in polymer systems. It is due to the extremely broad frequency and sensitivity range that can be covered by this technique. Information about localized and cooperative molecular fluctuations, polarization effects at interfaces, as well as charge transport processes can be deduced. Therefore, this book focusses on broadband dielectric spectroscopy of composite materials. Moreover, the dielectric studies are accompanied by mechanical spectroscopy, advanced calorimetry, NMR techniques, as well as transmission electron microscopy and X-ray scattering investigations.
Besides a brief introduction to (nano)composites, the book aims to address fundamental aspects of the molecular mobility in this innovative group of materials. Selected examples with scientific interest and some cases with high industrial impact were chosen. Due to the breadth of the subject, unfortunately not all topics could be addressed in detail, such as processing for instance.
Berlin, Andreas Schönhals
July 2021 Paulina Szymoniak
KW - Composite materials
KW - Nanocomposites
PY - 2022
SN - 978-3-030-89722-2
SN - 978-3-030-89723-9
DO - https://doi.org/10.1007/978-3-030-89723-9
VL - 2022
SP - 1
EP - 375
PB - Springer Nature
CY - Cham, Switzerland
AN - OPUS4-54538
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hahn, Marc Benjamin
A1 - Dietrich, P. M.
A1 - Radnik, Jörg
T1 - In situ monitoring of the influence of water on DNA radiation damage by near-ambient pressure X-ray photoelectron spectroscopy
N2 - Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS xperiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
KW - DNA
KW - XPS
KW - NAP-XPS
KW - Radiation damage
KW - Single-strand break (SSB)
KW - Double-strand break (DSB)
KW - Xray
KW - OH radical
KW - Hydroxyl radical
KW - LEE
KW - Low energy electrons
KW - Dosimetry
KW - Geant4
KW - Geant4-DNA
KW - TOPAS
KW - TOPAS-nbio
KW - Microdosimetry
KW - DNA radiation damage
KW - Direct damage
KW - Indirect damage
KW - Quasi-direct damage
KW - Hydration shell
KW - Dry DNA
KW - Hydrated DNA
KW - ROS
KW - Radical
KW - Reactive oxygen species
KW - Net-ionization reaction
KW - Radiation therapy
KW - Cancer therapy
KW - Xray photo electron spectrocopy
KW - Near ambient pressure xray photo electron spectroscopy
KW - Base damage
KW - Base loss
KW - Dissociative electron transfer (DET)
KW - Dissociative electron attachment (DEA)
KW - Hydrated electron
KW - Prehydrated electron
KW - Ionization
KW - PES
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524060
DO - https://doi.org/10.1038/s42004-021-00487-1
SN - 2399-3669
VL - 4
IS - 1
SP - 50
PB - Springer Nature
CY - London
AN - OPUS4-52406
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - In-situ monitoring of water dependent DNA and protein radiation damage by near-ambient-pressure XPS
N2 - X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. Our results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
T2 - ICRR 2023
CY - Montreal, Canada
DA - 26.08.2023
KW - DNA
KW - XPS
KW - Proteins
KW - Protein
KW - G5P
KW - Base damage
KW - Base loss
KW - Cancer treatment
KW - DEA
KW - DET
KW - DNA radiation damage
KW - Direct damage
KW - Dissociative electron attachment (DEA)
KW - Dissociative electron transfer (DET)
KW - Dosimetry
KW - ESCA
KW - Energy deposit
KW - Geant4
KW - Geant4-DNA
KW - Hydrated DNA
KW - Hydrated electron
KW - Hydrated electrons
KW - Hydration shell
KW - Hydroxyl radical
KW - Indirect damage
KW - Ionisation
KW - Ionization
KW - LEE
KW - Low energy electrons
KW - MCS
KW - Microdosimetry
KW - NAP-XPS
KW - Near ambient pressure xray photo electron spectroscopy
KW - Net-ionization reaction
KW - OH radical
KW - PES
KW - Particle scattering
KW - Prehydrated electron
KW - Presolvated electron
KW - Quasi-direct damage
KW - ROS
KW - Radiation damage
KW - Radiation therapy
KW - Radical
KW - Radiolysis
KW - Radiotherapy
KW - Reactive oxygen species
KW - Simulation
KW - Single-strand break (SSB)
KW - Single-stranded DNA-binding proteins
KW - TOPAS
KW - TOPAS-nbio
KW - TopasMC
KW - Xray photo electron spectrocopy
PY - 2023
AN - OPUS4-58214
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hahn, Marc Benjamin
T1 - Behind the paper: Radiation, DNA and water: New techniques for deeper insights
N2 - To gain deeper insights into the old questions about the influence of water on radiation interaction with DNA, new spectroscopic techniques had to be applied.
KW - DNA
KW - DNA radiation damage
KW - XPS
KW - Geant4
KW - Low energy electrons
KW - OH radical
KW - Hydrated DNA
KW - Hydration shell
KW - Double-strand break (DSB)
KW - Dissociative electron attachment (DEA)
KW - Single-strand break (SSB)
KW - LEE
KW - PES
KW - Ionization
KW - Reactive oxygen species
KW - ROS
KW - Base damage
KW - Base loss
KW - Cancer therapy
KW - TOPAS
KW - TOPAS-nbio
PY - 2021
UR - https://go.nature.com/3gjZVWG
SP - 1
EP - 3
PB - Springer Nature
CY - London
AN - OPUS4-52461
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - Near-ambient-pressure XPS as as tool to monitor DNA radiation damage directly in water
N2 - Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
T2 - Miller Conference
CY - Furiani, France
DA - 03.06.2023
KW - Base damage
KW - Base loss
KW - Cancer treatment
KW - DNA
KW - DNA radiation damage
KW - Direct damage
KW - Dissociative electron attachment (DEA)
KW - Dissociative electron transfer (DET)
KW - Dosimetry
KW - Double-strand break (DSB)
KW - ESCA
KW - Energy deposit
KW - G5P
KW - Geant4
KW - Geant4-DNA
KW - Hydrated DNA
KW - Hydrated electron
KW - Hydroxyl radical
KW - Indirect damage
KW - Ionisation
KW - Ionization
KW - LEE
KW - Low energy electrons
KW - MCS
KW - Microdosimetry
KW - NAP-XPS
KW - Near ambient pressure xray photo electron spectroscopy
KW - Net-ionization reaction
KW - OH radical
KW - PES
KW - Particle scattering
KW - Prehydrated electron
KW - Presolvated electron
KW - Protein
KW - Quasi-direct damage
KW - ROS
KW - Radiation damage
KW - Radiation therapy
KW - Radical
KW - Radiolysis
KW - Radiotherapy
KW - Reactive oxygen species
KW - Simulation
KW - Single-strand break (SSB)
KW - Single-stranded DNA-binding proteins
KW - TOPAS
KW - TOPAS-nbio
KW - XPS
KW - Xray
KW - Xray photo electron spectrocopy
KW - Hydration shell
PY - 2023
AN - OPUS4-57646
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - BP153: The change of DNA radiation damage upon hydration: In-situ observation by near-ambient pressure XPS
N2 - Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
T2 - DPG Frühjahrstagung
CY - Dresden, Germany
DA - 26.03.2023
KW - Base damage
KW - Base loss
KW - Cancer treatment
KW - DNA
KW - DNA radiation damage
KW - Direct damage
KW - Dissociative electron attachment (DEA)
KW - Dissociative electron transfer (DET)
KW - Dosimetry
KW - Double-strand break (DSB)
KW - Energy deposit
KW - Geant4
KW - Geant4-DNA
KW - Hydrated DNA
KW - Hydrated electron
KW - Hydration shell
KW - Hydroxyl radical
KW - Indirect damage
KW - Ionization
KW - LEE
KW - Low energy electrons
KW - MCS
KW - Microdosimetry
KW - NAP-XPS
KW - Near ambient pressure xray photo electron spectroscopy
KW - Net-ionization reaction
KW - OH radical
KW - PES
KW - Prehydrated electron
KW - Quasi-direct damage
KW - ROS
KW - Radiation damage
KW - Radiation therapy
KW - Radical
KW - Radiolysis
KW - Radiotherapy
KW - Reactive oxygen species
KW - Simulation
KW - Single-strand break (SSB)
KW - TOPAS
KW - TOPAS-nbio
KW - XPS
KW - Xray
KW - Xray photo electron spectrocopy
KW - Particle scattering
KW - Presolvated electron
KW - ESCA
PY - 2023
AN - OPUS4-57255
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hahn, Marc Benjamin
T1 - Near-Ambient-Pressure XPS to investigate radiation damage to DNA
N2 - X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. Our results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
T2 - Physical and Chemical Analysis of Polymers seminar
CY - Online meeting
DA - 12.10.2021
KW - Base damage
KW - Base loss
KW - Cancer therapy
KW - DNA
KW - DNA radiation damage
KW - Direct damage
KW - Dissociative electron attachment (DEA)
KW - Dissociative electron transfer (DET)
KW - Dosimetry
KW - Double-strand break
KW - DSB
KW - Dry DNA
KW - Geant4
KW - Geant4-DNA
KW - Hydrated DNA
KW - Hydrated electron
KW - Hydration shell
KW - Hydroxyl radical
KW - Indirect damage
KW - Ionization
KW - LEE
KW - Low energy electrons
KW - Microdosimetry
KW - NAP-XPS
KW - Near ambient pressure xray photo electron spectroscopy
KW - Net-ionization reaction
KW - OH radical
KW - PES
KW - Prehydrated electron
KW - Quasi-direct damage
KW - ROS
KW - Radiation damage
KW - Radiation therapy
KW - Radical
KW - Reactive oxygen species
KW - Single-strand break
KW - SSB
KW - TOPAS
KW - TOPAS-nbio
KW - XPS
KW - Xray
KW - Xray photo electron spectrocopy
PY - 2021
AN - OPUS4-53611
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bhattacharya, Biswajit
A1 - Michalchuk, Adam
A1 - Silbernagl, Dorothee
A1 - Rautenberg, Max
A1 - Schmid, Thomas
A1 - Feiler, Torvid
A1 - Reimann, K.
A1 - Ghalgaoui, A.
A1 - Sturm, Heinz
A1 - Paulus, B.
A1 - Emmerling, Franziska
T1 - A Mechanistic Perspective on Plastically Flexible Coordination Polymers
N2 - Mechanical flexibility in single crystals of covalently bound materials is a fascinating and poorly understood phenomenon. We present here the first example of a plastically flexible one-dimensional (1D) coordination polymer. The compound [Zn(m-Cl)2(3,5-dichloropyridine)2]n is flexible over two crystallographic faces. Remarkably, the single crystal remains intact when bent to 1808. A combination of microscopy, diffraction, and spectroscopic studies have been used to probe the structural response of the crystal lattice to mechanical bending. Deformation of the covalent polymer chains does not appear to be responsible for the observed macroscopic bending. Instead, our results suggest that mechanical bending occurs by displacement of the coordination polymer chains. Based on experimental and theoretical evidence, we propose a new model for mechanical flexibility in 1D coordination polymers. Moreover, our calculations propose a cause of the different mechanical properties of this compound and a structurally similar elastic material
KW - Coordination polymer
KW - Flexible crystals
KW - Mechanical properties
KW - Plastic deformation
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504755
DO - https://doi.org/10.1002/anie.201914798
VL - 59
IS - 14
SP - 5557
EP - 5561
PB - Wiley-VCH
AN - OPUS4-50475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wurzler, Nina
A1 - Sobol, Oded
A1 - Altmann, Korinna
A1 - Radnik, Jörg
A1 - Özcan Sandikcioglu, Özlem
T1 - Preconditioning of AISI 304 stainless steel surfaces in the presence of flavins—Part I: Effect on surface chemistry and corrosion behavior
N2 - Stainless steel AISI 304 surfaces were studied after a mild anodic polarization for oxide growth in the presence and absence of two derivatives of vitamin B2 (riboflavin and flavin mononucleotide) that can be secreted by metal‐reducing bacteria and act as a chelating agent for iron species. The alterations in oxide chemistry were studied by means of surface‐sensitive techniques such as X‐ray photoelectron spectroscopy and time‐of‐flight secondary ion mass spectrometry analysis. The complementary electrochemical characterization revealed a preferential growth of an oxide/hydroxide iron‐rich film that is responsible for an altered pit initiation and nucleation behavior. These findings suggest that as the corrosion behavior is determined by the interplay of the chemical and electronic properties, only a mild anodic polarization in the presence of redox‐active molecules is able to alter the chemical and electronic structure of the passive film formed on stainless steel AISI 304. This helps to achieve a profound understanding of the mechanisms of microbially influenced corrosion (MIC) and especially the possible effects of the redox‐active biomolecules, as they may play an important role in the corrosion susceptibility of stainless steel surfaces.
KW - Corrosion
KW - Stainless steel
KW - Surface analysis
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528117
DO - https://doi.org/10.1002/maco.202012191
VL - 72
IS - 6
SP - 974
EP - 982
PB - Wiley
AN - OPUS4-52811
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -