TY - JOUR
A1 - Krankenhagen, Rainer
T1 - Comment on "Sizing the depth and width of ideal delaminations using modulated photothermal radiometry" [J. Appl. Phys. 131, 085106 (2022)]
N2 - Comment on the article "Sizing the depth and width of ideal delaminations using modulated photothermal radiometry" by Agustín Salazar and Arantza Mendioroz, Journal of Applied Physics 131, 085106 (2022, https://doi.org/10.1063/5.0085178).
KW - Ideal delamination
KW - Modulated photothermal radiometry
KW - Delamination depth
KW - Delamination width
PY - 2022
DO - https://doi.org/10.1063/5.0107603
VL - 132
SP - 1
PB - AIP
CY - Melville, NY
AN - OPUS4-56261
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tengattini, A
A1 - Kardjilov, N
A1 - Helfen, L
A1 - Douissard, P A
A1 - Lenoir, N
A1 - Markötter, Henning
A1 - Hilger, A
A1 - Arlt, T
A1 - Paulisch, M
A1 - Turek, T
A1 - Manke, Ingo
T1 - Compact and versatile neutron imaging detector with sub-4μm spatial resolution based on a single-crystal thin-film scintillator
N2 - A large and increasing number of scientific domains pushes for high neutron imaging resolution achieved in reasonable times. Here we present the principle, design and performance of a detector based on infinity corrected optics combined with a crystalline Gd3Ga5O12 : Eu scintillator, which provides an isotropic sub-4 μm true resolution. The exposure times are only of a few minutes per image. This is made possible also by the uniquely intense cold neutron flux available at the imaging beamline NeXT-Grenoble. These comparatively rapid acquisitions are compatible with multiple high quality tomographic acquisitions, opening new venues for in-operando testing, as briefly exemplified here.
KW - Neutron imaging
KW - Scintillator
KW - Resolution
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549836
DO - https://doi.org/10.1364/oe.448932
VL - 30
IS - 9
SP - 14461
EP - 14477
PB - Optica
CY - Washington, DC
AN - OPUS4-54983
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nourinejhad Zarghani, Shaheen
A1 - Monavari, Mehran
A1 - Ehlers, Jens
A1 - Hamacher, Joachim
A1 - Büttner, Carmen
A1 - Bandte, Martina
T1 - Comparison of Models for Quantification of Tomato Brown Rugose Fruit Virus Based on a Bioassay Using a Local Lesion Host
N2 - Considering the availability of serological and molecular biological methods, the bioassay has been paled into insignificance, although it is the only experimental method that can be used to demonstrate the infectivity of a virus. We compared goodness-of-fit and predictability power of five models for the quantification of tomato brown rugose fruit virus (ToBRFV) based on local lesion assays: the Kleczkowski model, Furumoto and Mickey models I and II, the Gokhale and Bald model (growth curve model), and the modified Poisson model. For this purpose, mechanical inoculations onto Nicotiana tabacum L. cv. Xanthi nc and N. glutionosa L. with defined virus concentrations were first performed with half-leaf randomization in a Latin square design. Subsequently, models were implemented using Python software and fitted to the number of local lesions. All models could fit to the data for quantifying ToBRFV based on local lesions, among which the modified Poisson model had the best prediction of virus concentration in spike samples based on local lesions, although data of individual indicator plants showed variations. More accurate modeling was obtained from the test plant N. glutinosa than from N. tabacum cv. Xanthi nc. The position of the half-leaves on the test plants had no significant effect on the number of local lesions.
KW - Plant Science
KW - Ecology
KW - Evolution
KW - Behavior and Systematics
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-585506
DO - https://doi.org/10.3390/plants11243443
VL - 11
IS - 24
SP - 1
EP - 16
PB - MDPI
AN - OPUS4-58550
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - BOOK
A1 - Cohen, Zina
T1 - Composition Analysis of Writing Materials in Cairo Genizah Documents
N2 - Through the application of scientific methods of analysis to a corpus of medieval manuscripts found in the Cairo Genizah, this work aims to gain a better understanding of the writing materials used by Jewish communities at that time, shedding new light not only on the production of manuscripts in the Middle Ages, but also on the life of those Jewish communities.
KW - Ink analyses
KW - Cairo Genizah
KW - X-Ray fluorescence analyses
KW - Reflectography
KW - Middle Ages
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588642
UR - https://brill.com/display/title/59331
SN - 978-90-04-44887-2
SN - 978-90-04-46935-8
SP - 1
EP - 192
PB - Brill
CY - Leiden & Boston
AN - OPUS4-58864
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Radnik, Jörg
A1 - Knigge, Xenia
A1 - Andresen, Elina
A1 - Resch-Genger, Ute
A1 - Cant, D.J.H.
A1 - Shard, A.G.
A1 - Clifford, C.A.
T1 - Composition, thickness, and homogeneity of the coating of core–shell nanoparticles—possibilities, limits, and challenges of X-ray photoelectron spectroscopy
N2 - Core–shell nanoparticles have attracted much attention in recent years due to their unique properties and their increasing importance in many technological and consumer products. However, the chemistry of nanoparticles is still rarely investigated in comparison to their size and morphology. In this review, the possibilities, limits, and challenges of X-ray photoelectron spectroscopy (XPS) for obtaining more insights into the composition, thickness, and homogeneity of nanoparticle coatings are discussed with four examples: CdSe/CdS quantum dots with a thick coating and a small core; NaYF4-based upconverting nanoparticles with a large Yb-doped core and a thin Er-doped coating; and two types of polymer nanoparticles with a poly(tetrafluoroethylene) core with either a poly(methyl methacrylate) or polystyrene coating. Different approaches for calculating the thickness of the coating are presented, like a simple numerical modelling or a more complex simulation of the photoelectron peaks. Additionally, modelling of the XPS background for the investigation of coating is discussed. Furthermore, the new possibilities to measure with varying excitation energies or with hard-energy X-ray sources (hard-energy X-ray photoelectron spectroscopy) are described. A discussion about the sources of uncertainty for the determination of the thickness of the coating completes this review.
KW - X-ray spectroscopy
KW - Nanoparticles
KW - Spectroscopy / Instrumentation
KW - Spectroscopy / Theory
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548305
DO - https://doi.org/10.1007/s00216-022-04057-9
VL - 414
IS - 15
SP - 4331
EP - 4345
PB - SpringerNature
AN - OPUS4-54830
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kolmangadi, Mohamed Aejaz
T1 - Confinement induced relaxations and phase behavior of a nanoconfined ionic liquid crystal
N2 - Liquid crystalline mesophases in nanoconfinement exhibit intriguing phase transition behaviors and relaxation dynamics. Here in, we investigate the molecular dynamics and electrical conductivity of a linear shaped guanidinium based ILC confined in self-ordered nano porous alumina oxide membranes of pore size ranging from 180nm down to 25nm by employing broadband dielectric spectroscopy (BDS) and calorimetry. Calorimetric investigation reveals a complete suppression of the columnar – isotropic transition, while the plastic crystalline – columnar transition temperature decreases with inverse pore size and deviates from the Gibbs – Thomson equation.
For the bulk case, BDS detects two relaxation modes in the crystalline phase, the relaxation and the α1 relaxation, and two relaxation modes in the columnar phase, the α2 and α3 relaxation. For the confined case, all relaxation modes slow down compared to the bulk. However, for the least pore size (25 nm), the α2 relaxation is absent. We discuss the possible molecular origins of the different relaxation modes observed. For the bulk ILC, a clear jump of 4 orders of magnitude in the absolute values of DC conductivity occurs at the transition from the plastic crystalline to hexagonal columnar phase, for the confined ILC, this transition is smooth. DC conductivity is reduced for the confined case, except for the 25nm, where the values is similar to the bulk.
T2 - 11th IDS conference 2022
CY - San Sebastian, Spain
DA - 03.09.2022
KW - Ionic Liquid crystals
KW - Nanoconfinement
KW - Conductivity
PY - 2022
AN - OPUS4-55879
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bernges, T.
A1 - Hanus, R.
A1 - Wankmiller, B.
A1 - Imasato, K.
A1 - Lin, S.
A1 - Ghidiu, M.
A1 - Gerlitz, M.
A1 - Peterlechner, M.
A1 - Graham, S.
A1 - Hautier, G.
A1 - Pei, Y.
A1 - Hansen, M. R.
A1 - Wilde, G.
A1 - Snyder, G. J.
A1 - George, Janine
A1 - Agne, M T.
A1 - Zeier, W. G.
T1 - Considering the Role of Ion Transport in Diffuson-Dominated Thermal Conductivity
N2 - Next-generation thermal management requires the development of low lattice thermal conductivity materials, as observed in ionic conductors. For example, thermoelectric efficiency is increased when thermal conductivity is decreased. Detrimentally, high ionic conductivity leads to thermoelectric device degradation. Battery safety and design also require an understanding of thermal transport in ionic conductors. Ion mobility, structural complexity, and anharmonicity have been used to explain the thermal transport properties of ionic conductors. However, thermal and ionic transport are rarely discussed in direct comparison. Herein, the ionic conductivity of Ag+ argyrodites is found to change by orders of magnitude without altering the thermal conductivity. Thermal conductivity measurements and two-channel lattice dynamics modeling reveal that the majority of Ag+ vibrations have a non-propagating diffuson-like character, similar to amorphous materials. It is found that high ionic mobility is not a requirement for diffuson-mediated transport. Instead, the same bonding and structural traits that can lead to fast ionic conduction also lead to diffuson-mediated transport. Bridging the fields of solid-state ionics and thermal transport, it is proposed that a vibrational perspective can lead to new design strategies for functional ionic conducting materials. As a first step, the authors relate the so-called Meyer-Neldel behavior in ionic conductors to phonon occupations.
KW - Diffusons
KW - DFT
KW - Phonons
KW - Thermoelectrics
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547140
DO - https://doi.org/10.1002/aenm.202200717
SN - 1614-6832
VL - 12
IS - 22
SP - 1
EP - 13
PB - Wiley VHC-Verlag
AN - OPUS4-54714
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Meng, M.
A1 - Zhang, R.
A1 - Fa, X.
A1 - Yang, J.
A1 - Cheng, Z.
A1 - Qiao, X.
A1 - Ou, J.
A1 - Würth, Christian
A1 - Resch-Genger, Ute
T1 - Core−Shell NaYF4:Yb3+/Tm3+@NaGdF4:Ce3+/Eu3+ Nanoparticles for Upconversion and Downconversion Dual-Mode Fluorescence-Based Temperature Sensing
N2 - NaYF4 as the core and NaGdF4 as the outer layer were used to obtain
NaYF4:Yb3+/Tm3+@NaYF4:Ce3+/Eu3+ nanoparticles. Physical and morphological investigations indicated that the obtained nanoparticles were prepared in a hexagonal shape, with the NaGdF4 shell layer uniformly encapsulated on the NaYF4 core.
Strong Tm3+ upconversion emission peaks were observed for a 980-nm-laser-excited sample, while strong Eu3+ downconversion emission peaks were observed for a 254-nm-laser-excited sample. By zonal doping of Tm3+ and Eu3+, their fluorescence intensity can be significantly increased; more importantly, simultaneous temperature measurements with dual-mode upconversion/downconversion can be achieved. The temperature measurement properties of the dual mode were also investigated, and it was discovered that the upconversion 3F3 → 3H6 and 1G4 → 3F4 thermocouple energy levels gave the best temperature measurements with maximum absolute and relative sensitivities of 0.0877 K−1 and 1.95% K−1, respectively, which are better than the current temperature measurement sensitivities of most rare-earth-based materials. This material was prepared as fiber-optic temperature-sensing probes to detect the temperature in the environment in real time and was found to perform excellently for temperature measurement.
KW - Upconversion nanoparticle
KW - Lanthanide
KW - Sensing; temperature
KW - Photophysics
PY - 2022
DO - https://doi.org/10.1021/acsanm.2c01611
VL - 5
IS - 7
SP - 9266
EP - 9276
PB - American Chemical Society
AN - OPUS4-55363
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schmid, Thomas
A1 - Hodoroaba, Vasile-Dan
T1 - Correlative Analysis by Raman and other Micro & Nanospectroscopic Imaging Techniques
N2 - In the present talk the basics of the Raman spectroscopy and particularly of Raman microscopy are explained. Advantages and disadvantages of the method are highlighted through selected case studies. In the second part of the lecture examples of correlative imaging with electron, X-ray, ion and optical microscopies from micro- to the nanoscale are highlighted.
T2 - Charisma School on Raman Harmonisation
CY - Turin, Italy
DA - 19.10.2022
KW - Raman
KW - Correlative Imaging
KW - Microscopy
KW - Hyperspectral imaging
PY - 2022
UR - https://amdgroup.inrim.it/events/vamas-sc-meeting-47/program-sc47
AN - OPUS4-56094
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bender, R.
A1 - Féron, D.
A1 - Mills, D.
A1 - Ritter, S.
A1 - Bäßler, Ralph
A1 - Bettge, Dirk
A1 - de Graeve, I.
A1 - Dugstad, A.
A1 - Grassini, S.
A1 - Hack, T.
A1 - Halama, M.
A1 - Han, E.-H.
A1 - Harder, T.
A1 - Hinds, G.
A1 - Kittel, J.
A1 - Krieg, R.
A1 - Leygraf, C.
A1 - Martinelli, L.
A1 - Mol, A.
A1 - Neff, D.
A1 - Nilsson, J.-O.
A1 - Odnevall, I.
A1 - Paterson, S.
A1 - Paul, S.
A1 - Prošek, T.
A1 - Raupach, M.
A1 - Revilla, R. I.
A1 - Ropital, F.
A1 - Schweigart, H.
A1 - Szala, E.
A1 - Terryn, H.
A1 - Tidblad, J.
A1 - Virtanen, S.
A1 - Volovitch, P.
A1 - Watkinson, D.
A1 - Wilms, M.
A1 - Winning, G.
A1 - Zheludkevich, M.
T1 - Corrosion challenges towards a sustainable society
N2 - A global transition towards more sustainable, affordable and reliable energy systems is being stimulated by the Paris Agreement and the United Nation's 2030 Agenda for Sustainable Development. This poses a challenge for the corrosion industry, as building climate‐resilient energy systems and infrastructures brings with it a long‐term direction, so as a result the long‐term behaviour of structural materials (mainly metals and alloys) becomes a major prospect. With this in mind “Corrosion Challenges Towards a Sustainable Society” presents a series of cases showing the importance of corrosion protection of metals and alloys in the development of energy production to further understand the science of corrosion, and bring the need for research and the consequences of corrosion into public and political focus. This includes emphasis on the limitation of greenhouse gas emissions, on the lifetime of infrastructures, implants, cultural heritage artefacts, and a variety of other topics.
KW - Corrosion
KW - Corrosion costs
KW - Corrosion protection
KW - Preventive strategies
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554801
DO - https://doi.org/10.1002/maco.202213140
SN - 1521-4176
VL - 73
IS - 11
SP - 1730
EP - 1751
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-55480
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sieg, H.
A1 - Klusmann, L.
A1 - Ellermann, A. L.
A1 - Böhmert, L.
A1 - Thünemann, Andreas
A1 - Braeuning, A.
T1 - Counterions determine uptake and effects of aluminum in human intestinal and liver cells
N2 - Aluminum (Al) is highly abundant in the biosphere and can occur in different physico-chemical states. It is present in human food and undergoes transitions between dissolved and particulate species during the passage of the gastrointestinal tract. Moreover, in a complex matrix such as food different inorganic and organic counterions can affect the chemical behavior of Al following oral uptake.
In this work, the effects of different counterions, namely chloride, citrate, sulfate, lactate and acetylacetonate, on Al uptake and toxicity in the human intestine are studied. The respective Al salts showed different dissolution behavior in biological media and formed nanoscaled particles correlating in reverse with the amount of their dissolved fraction. The passage through the intestinal barrier was studied using a Caco-2 Transwell® system, showing counterion-dependent variance in cellular uptake and transport. In addition, Al toxicity was investigated using Al species (Al3+, metallic Al0 and oxidic γAl2O3 nanoparticles) and counterions individually or in mixtures on Caco-2 and HepG2 cells. The strongest toxicity was observed using a combination of Al species, depending on solubility, and the lipophilic counterion acetylacetonate. Notably, only the combination of both led to toxicity, while both substances individually did not show toxic effects. A toxification of previously non-toxic Al-species by the presence of acetylacetonate is shown here for the first time. The dependency on the concentration of free Al ions was demonstrated using sodium hydrogen phosphate, which was able to counteract the toxic effects by complexing free Al ions.
These findings, using Al salts as an example for a common food contaminant, underline the importance of a consideration of the chemical properties of human nutrition, especially dissolution and hydrophobicity, which can significantly influence the cellular uptake and effects of xenobiotic substances.
KW - SAXS
KW - Small-angle X-ray scattering
KW - Nanoparticle
PY - 2022
DO - https://doi.org/10.1016/j.tiv.2021.105295
VL - 79
SP - 1
EP - 7
PB - Elsevier
AN - OPUS4-54110
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bresch, Harald
A1 - Hodoroaba, Vasile-Dan
A1 - Schmidt, Alexandra
A1 - Rasmussen, K.
A1 - Rauscher, H.
T1 - Counting Small Particles in Electron Microscopy Images — Proposal for Rules and Their Application in Practice
N2 - Electron microscopy (EM) is the gold standard for the characterisation of the morphology (size and shape) of nanoparticles. Visual observation of objects under examination is always a necessary first step in the characterisation process. Several questions arise when undertaking to identify and count particles to measure their size and shape distribution. In addition to challenges with the dispersion and identification of the particles, more than one protocol for counting particles is in use. This paper focuses on precise rules for the counting of particles in EM micrographs, as this influences the measurement accuracy of the number of particles, thus implicitly affecting the size values of the counted particles. We review and compare four different, commonly used methods for counting, which we then apply in case studies. The impact of the selected counting rule on the obtained final particle size distribution is highlighted. One main aim of this analysis is to support the application of a specific, well-defined counting approach in accordance with regulatory
requirements to contribute to achieving more reliable and reproducible results. It is also useful for the new harmonised measurement procedures for determining the particle size and particle size distribution of nanomaterials.
KW - Nano
KW - Particle size distribution
KW - Nanoparticle
KW - Nanomaterial
KW - OECD
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551891
DO - https://doi.org/10.3390/nano12132238
SN - 2079-4991
VL - 12
IS - 13
SP - 2238
PB - MDPI
CY - Basel
AN - OPUS4-55189
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Falkenhagen, Jana
T1 - Coupling of chromatographic and spectrometric techniques for polymer characterization
N2 - Coupling of chromatographic and spectrometric techniques for polymer characterization; focus topics: LCxMALDI-TOF-MS and UPLC x ESI-TOF-MS
T2 - 16. Tagung des Arbeitskreises Polymeranalytik
CY - Online meeting
DA - 22.03.2022
KW - Liquid chromatography
KW - Mass spectrometry
KW - Polymers
KW - Two-dimensional chromatography (2D-LC)
PY - 2022
AN - OPUS4-54567
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ávila Calderón, Luis
A1 - Rehmer, Birgit
A1 - Schriever, Sina
A1 - Ulbricht, Alexander
A1 - Agudo Jácome, Leonardo
A1 - Sommer, Konstantin
A1 - Mohr, Gunther
A1 - Skrotzki, Birgit
A1 - Evans, Alexander
T1 - Creep and creep damage behavior of stainless steel 316L manufactured by laser powder bed fusion
N2 - This study presents a thorough characterization of the creep properties of austenitic stainless steel 316L produced by laser powder bed fusion (LPBF 316L) contributing to the sparse available data to date. Experimental results (mechanical tests, microscopy, X-ray computed tomography) concerning the creep deformation and damage mechanisms are presented and discussed. The tested LPBF material exhibits a low defect population, which allows for the isolation and improved understanding of the effect of other typical aspects of an LPBF microstructure on the creep behavior. As a benchmark to assess the material properties of the LPBF 316L, a conventionally manufactured variant of 316L was also tested. To characterize the creep properties, hot tensile tests and constant force creep tests at 600 °C and 650 °C are performed. The creep stress exponents of the LPBF material are smaller than that of the conventional variant. The primary and secondary creep stages and the times to rupture of the LPBF material are shorter than the hot rolled 316L. Overall the creep damage is more extensive in the LPBF material. The creep damage of the LPBF material is overall mainly intergranular. It is presumably caused and accelerated by both the appearance of precipitates at the grain boundaries and the unfavorable orientation of the grain boundaries. Neither the melt pool boundaries nor entrapped gas pores show a significant influence on the creep damage mechanism.
KW - 316L
KW - Laser Powder Bed Fusion (LPBF)
KW - Creep behavior
KW - Additive Manufacturing
KW - AGIL
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-539373
DO - https://doi.org/10.1016/j.msea.2021.142223
SN - 0921-5093
VL - 830
SP - 142223
PB - Elsevier B.V.
AN - OPUS4-53937
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CHAP
A1 - Fedelich, Bernard
ED - Cailletaud, G.
ED - Cormier, J.
ED - Eggeler, G.
ED - Maurel, V.
ED - Nazé, L.
T1 - Crystal orientation and elastic properties
N2 - The elastic constants are the most basic mechanical properties of a material and are needed for any structural analysis of a component. For example, they have a major influence on the eigenfrequencies of vibrating parts. Single crystals of Ni-base superalloys are strongly anisotropic, which means that the observed properties are orientation dependent. Tensor algebra is then required to mathematically formulate the elastic properties and their relations to the crystal orientation. Hence, this chapter first summarizes some basic definitions and calculation rules for Rotation matrices, including the definition of the Euler angles, which are most commonly used to define the relative orientations of the crystal and the component. Parts of this chapter closely follow the lines of the excellent exposition of the topic by Olschewski.
KW - Nickel-base superalloys
KW - Elasticity
PY - 2022
SN - 978-0-12-819357-0
SP - 41
EP - 67
PB - Elsevier Inc.
AN - OPUS4-53435
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CHAP
A1 - Fedelich, Bernard
ED - Cailletaud, G.
ED - Cormier, J.
ED - Eggeler, G.
ED - Maurel, V.
ED - Nazé, L.
T1 - Crystal plasticity models: dislocation based
N2 - The large number of TEM investigations and the regular microstructure
of single-crystal nickel-base superalloys has boosted the development of a number of physically motivated constitutive laws. In contrast to the more phenomenological models discussed in the next chapter, these models use dislocation densities as internal variables. Obvious advantages are that the computed densities can be compared to TEM observations and the Deformation mechanisms can be easier translated into mathematical equations.
KW - Nickel-base superalloys
KW - Creep
KW - Plasticity
PY - 2022
SN - 978-0-12-819357-0
SP - 401
EP - 427
PB - Elsevier Inc.
ET - 1
AN - OPUS4-53436
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Weinel, Kristina
T1 - Damage induced by electric field of microparticles in the electron microscope
N2 - Damage induced by electric field (DIEF) that happens in the transmission electron microscope (TEM) when converging the electron beam (e-beam) on microparticles (MPs) can be used to synthesis new nanomaterial and nanomaterial compositions. The research questions are to clarify the limits and possibilities of the method regarding materials that can be produced, systems to which it is applicable and working beam parameters. Synthesis of nano-objects from microparticles using DIEF in TEM could be shown for different materials. Additionally, DIEF using the e-beam in a scanning electron microscope (SEM) can also be used to synthesis nano-objects. A deeper material analysis of this nano-objects was done using TEM and shows that the material of the nanoparticles (NPs) can be gold or/and silicon. Furthermore, the size of the NPs depends on the distance to the center of DIEF whereby the larger NPs are closer to the center. The areas of gold NPs are promising candidates for plasmonic or photonic devices for energy storage or transport.
T2 - PhD-Day 2022
CY - Berlin, Germany
DA - 06.09.2022
KW - Electron microscopy
KW - Electron beam induced modification
KW - Gold nanoparticles
PY - 2022
AN - OPUS4-58264
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhang, X.
A1 - Zhang, J.
A1 - Wang, H.
A1 - Rogal, J:
A1 - Li, H.-Y.
A1 - Wei, S.-H.
A1 - Hickel, Tilmann
T1 - Defect-characterized phase transition kinetics
N2 - Phase transitions are a common phenomenon in condensed matter and act as a critical degree of freedom that can be employed to tailor the mechanical or electronic properties of materials. Understanding the fundamental mechanisms of the thermodynamics and kinetics of phase transitions is, thus, at the core of modern materials design. Conventionally, studies of phase transitions have, to a large extent, focused on pristine bulk phases. However, realistic materials exist in a complex form; their microstructures consist of different point and extended defects. The presence of defects impacts the thermodynamics and kinetics of phase transitions, but has been commonly ignored or treated separately. In recent years, with the significant advances in theoretical and experimental techniques, there has been an increasing research interest in modeling and characterizing how defects impact or even dictate phase transitions. The present review systematically discusses the recent progress in understanding the kinetics of defect-characterized phase transitions, derives the key mechanisms underlying these phase transitions, and envisions the remaining challenges and fruitful research directions. We hope that these discussions and insights will help to inspire future research and development in the field.
KW - Kinetics
KW - Atomistic models
KW - Phase transitions
KW - Defects
PY - 2022
DO - https://doi.org/10.1063/5.0117234
SN - 1931-9401
VL - 9
IS - 4
SP - 1
EP - 42
PB - AIP
CY - New York, NY
AN - OPUS4-56507
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mohamed, W. A. A.
A1 - Fahmy, Alaa
A1 - Helal, A.
A1 - Ahmed, E. A. E.
A1 - Elsayed, B. A.
A1 - Kamoun, E. A.
A1 - Gad, E. A. M.
T1 - Degradation of local Brilliant Blue R dye in presence of polyvinylidene fluoride/MWCNs/TiO2 as photocatalysts and plasma discharge
N2 - The need of clean water and the water-poor are increasing daily in the world. In addition, we are facing a dramatic increase in the industrial pollutions of rivers and groundwater, which led us to find a new way to treat industrial pollutants. The plasma discharge technique is one of the important, safe, and applicable for industrial wastewater decontamination. Decolorization of Brilliant Blue R (BBR) dye as a hazard material was noticed when the contaminated solution was exposed to the plasma discharge technique. The combination between the nonthermal plasma and catalysts was evaluated in this work to optimize the degradation efficiency. The PVDF/(MWCNTs/TiO2) as three system composites was employed to enhance the nonthermal plasma performance. The surface area, phase purity, shape, and photonic efficiency were characterized employing XRD, FTIR, SEM, DSC, and UV–Vis. techniques. The obtained results of degradation using NTP technique in presence of the PVDF/MWCNTs catalyst have been enhanced the BBR dye degradation by 19% than only plasma treatment for 20 min.
The durability processes of prepared PVDF/(MWCNTs/TiO2) was investigated and evaluated until 8 solar photocatalytic process repeating times.
KW - Brilliant Blue R
KW - MWCNT
KW - PVDF
PY - 2022
DO - https://doi.org/10.1016/j.jece.2021.106854
VL - 10
IS - 1
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-54386
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Design, characterization, and application of fluorescent sensor particles
N2 - pH and oxygen are amongst the most important and frequently measured analytes in the life and material sciences, indicating, e.g., diseases and corrosion processes. This includes the optical monitoring of pH in living cells for studying cellular internalization pathways, such as phagocytosis, endocytosis, and receptor ligand internalization with the aid of molecular and nanoscale fluorescent sensors. Nanoparticle (NP)-based sensors, that are labeled or stained with a multitude of sensor dyes, have several advantages as compare to conventional molecular probes like enhanced brightness, i.e., amplified signals, ease of designing ratiometric systems by combining analyte sensitive and inert reference dyes, and increased photostability. Moreover, this can enable the use of hydrophobic dyes in aqueous environments. Versatile templates and carriers for the fabrication of nanosensors by the staining and/or labelling with different fluorophores and sensor molecules or surface functionalized NP like silica (SiO2-NP) and polystyrene (PS-NP) particles provide. Here we present the design of a versatile platform of color emissive nanosensors and stimuli-responsive microparticles for the measurement of pH, oxygen, and other targets utilizing both types of matrices and sets of spectrally distinguishable sensor and reference dyes and their characterization and demonstrate the applicability of representative sensor particle for cellular studies.
T2 - Vortrag bei dem Projekttreffen MicraGen
CY - Copenhagen, Denmark
DA - 18.08.2022
KW - Dye
KW - Luminescence
KW - Quantitative spectroscopy
KW - Photophysics
KW - Quality assurance
KW - Nano
KW - Particle
KW - Quantum yield
KW - Lifetime
KW - Standard
KW - Integrating sphere spectroscopy
KW - Sensor
KW - pH
KW - Oxygen
KW - Microfluidics
KW - Cancer
KW - Cell
KW - Life sciences
PY - 2022
AN - OPUS4-57049
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - THES
A1 - Müller, Anja
T1 - Determination of the actual morphology of core-shell nanoparticles by advanced X-ray analytical techniques: A necessity for targeted and safe nanotechnology
N2 - Even though we often do not knowingly recognize them, nanoparticles are present these days in most areas of our daily life, including food and its packaging, medicine, pharmaceuticals, cosmetics, pigments as well as electronic products, such as computer screens. The majority of these particles exhibits a core-shell morphology either intendedly or unintendedly. For the purpose of practicability, this core-shell nanoparticle (CSNP) morphology is often assumed to be ideal, namely a spherical core fully encapsulated by a shell of homogeneous thickness with a sharp interface between core and shell material. It is furthermore widely presumed that all nanoparticles in the sample possess the same shell thickness. As a matter of fact, most real CSNPs deviate in several ways from this ideal model with quite often severe impact on how efficiently they perform in a specific application.
The topic of this cumulative PhD thesis is the accurate characterization of the actual morphology of CSNPs by advanced X-ray analytical techniques, namely X-ray photoelectron spectroscopy (XPS) and scanning transmission X-ray microscopy (STXM). A special focus is on CSNPs which deviate from an ideal core-shell morphology. In the paper from 2019 nanoparticle shell thicknesses are extracted from the elastic-peak intensities in an XPS spectrum based on an ideal particle morphology. This happens for a series of CSNP samples comprising a poly(tetrafluoroethylene) (PTFE) core and either a poly(methyl methacrylate) (PMMA) or polystyrene (PS) shell. The same paper as well as the paper from 2020 demonstrate for the first time, that the analysis of the inelastic background in an XPS spectrum of CSNPs can identify and quantify the heterogeneity of the shell and the incomplete encapsulation of the core.
The result from an XPS experiment is always an average across a large nanoparticle ensemble. Deviations from an ideal morphology within a single particle of the sample cannot be assessed separately. As opposed to that, a spatial resolution of 35 nm enables STXM to visualize the interior of single CSNPs which exhibit a sufficient X-ray absorption contrast between core and shell material. In the paper from 2018 a STXM analysis is demonstrated based on the example of the PTFE-PS CSNP samples already mentioned in the previous paragraph.
In the publication from 2021 (Ca/Sr)F₂ core-shell like nanoparticle ensembles for the practical use in, among others, antireflective coatings are investigated. These nanoparticles do not possess a sharp interface between core and shell material, which is why a shell thickness determination as described in the second paragraph is inappropriate. Instead, in-depth profiles of the chemical composition are obtained by XPS experiments based on synchrotron radiation with variable X-ray photon energy to elucidate the internal morphology of the particles. Additionally, theoretical in-depth profiles of Ca and Sr XPS peak intensities are simulated, in order to facilitate the interpretation of the experiments. Thus, an enrichment of CaF₂ at the particle surface was determined, which could hardly have been assessed by any other analytical technique. Because this kind of non-destructive depth profiling by XPS is very demanding, more than usual effort is spent on gapless documentation of the experiments to ensure full reproducibility.
Due to the vast diversity of nanoparticles differing in material, composition and shape, a measurement procedure cannot unalteredly be transferred from one sample to another. Nevertheless, because the papers in this thesis present a greater depth of reporting on the experiments than comparable publications, they constitute an important guidance for other scientists on how to obtain meaningful information about CSNPs from surface analysis.
N2 - Obwohl wir sie oft nicht bewusst wahrnehmen, sind Nanopartikel heutzutage in den meisten Bereichen unseres Alltags präsent, unter anderem in Lebensmitteln und ihren Verpackungen, Medizin, Medikamenten, Kosmetik, Pigmenten und in elektronischen Geräten wie Computermonitoren. Ein Großteil dieser Partikel weist, beabsichtigt oder unbeabsichtigt, eine Kern-Schale Morphologie auf. Einfachheitshalber wird diese Morphologie eines Kern-Schale-Nanopartikels (CSNP) oft als ideal angenommen, d.h. als ein sphärischer Kern, der komplett von einer Schale homogener Dicke bedeckt ist, mit einer scharfen Grenzfläche zwischen Kern- und Schalenmaterial. Außerdem wird vielfach auch davon ausgegangen, alle Partikel der Probe hätten gleiche Schalendicken. Tatsächlich weichen die meisten realen CSNPs in verschiedenster Weise von diesem Idealmodell ab, mit oft drastischen Auswirkungen darauf, wie gut sie ihre Aufgabe in einer bestimmten Anwendung erfüllen.
Das Thema dieser kumulativen Doktorarbeit ist die exakte Charakterisierung der wirklichen Morphologie von CSNPs mit modernen Röntgen-basierten Methoden, konkret Röntgen-Photoelektronen-Spektroskopie (XPS) und Raster-Transmissions-Röntgen-Mikroskopie (STXM). Der Fokus liegt insbesondere auf CSNPs, die von einer idealen Kern-Schale-Morphologie abweichen. Im Artikel von 2019 werden Schalendicken von Nanopartikeln aus den elastischen Peakintensitäten im XPS-Spektrum unter Annahme einer idealen Partikelmorphologie abgeleitet. Dies geschieht für eine Reihe von CSNP-Proben, welche aus einem Polytetrafluoroethylen- (PTFE) Kern und entweder einer Polymethylmethacrylat- (PMMA) oder Polystyrol- (PS) Schale bestehen. Sowohl dieser Artikel als auch der von 2020 zeigen erstmals, dass die Auswertung des inelastischen Untergrunds eines CSNP-XPS-Spektrums in der Lage ist, die Heterogenität der Schale und die unvollständige Ummantelung des Kerns zu identifizieren und zu quantifizieren.
Das Ergebnis eines XPS-Experiments ist immer ein Mittelwert über ein großes Nanopartikelensemble. Inwiefern ein einzelner Partikel innerhalb der Probe von einer idealen Morphologie abweicht, kann nicht gesondert erfasst werden. Im Gegensatz dazu kann STXM mit einer räumlichen Auflösung von 35 nm das Innere einzelner CSNPs visualisieren, sofern sie genügend Röntgenabsorptionskontrast zwischen Kern- und Schalenmaterial aufweisen. Im Artikel von 2018 wird am Beispiel der bereits im vorherigen Abschnitt genannt PTFE-PS-CSNPProben eine solche STXM-Untersuchung demonstriert.
In der Veröffentlichung von 2021 werden Kern-Schale-artige (Ca/Sr)F₂-Nanopartikel für den praktischen Einsatz in unter anderem entspiegelnden Beschichtungen untersucht. Da hier keine scharfe Grenzfläche zwischen Kern- und Schalenmaterial vorliegt, ist eine Schalendickenbestimmung, wie sie im zweiten Abschnitt diskutiert wird, nicht sinnvoll. Stattdessen werden mit Hilfe von XPS, angeregt mit Synchrotronstrahlung bei variabler Röntgenphotonenenergie, Tiefenprofile der chemischen Zusammensetzung generiert, um die innere Morphologie der Partikel aufzuklären. Zusätzlich werden theoretische Tiefenprofile der Ca- und Sr-XPS-Peakintensitäten simuliert, um die Interpretation der Experimente zu erleichtern. So wurde eine CaF₂-Anreicherung an der Oberfläche der Partikel festgestellt, die kaum mit einer anderen analytischen Methode hätte entdeckt werden können. Da diese zerstörungsfreie Bestimmung von XPS-Tiefenprofilen sehr anspruchsvoll ist, wird noch mehr als üblich auf die lückenlose Dokumentation des Experiments geachtet, um vollständige Reproduzierbarkeit zu gewährleisten.
Aufgrund der enormen Vielfalt an CSNPs, die sich in Material, Zusammensetzung und Form unterscheiden, kann eine Messmethode nicht völlig unverändert von einer Probe auf eine andere übertragen werden. Nichtsdestotrotz, da die als Teil dieser Doktorarbeit präsentierten Artikel eine deutlich ausführlichere Beschreibung der Experimente enthalten als vergleichbare Publikationen, stellen sie eine wichtige Anleitung für andere Wissenschaftler dafür dar, wie aussagekräftige Informationen über CSNPs durch Oberflächenanalytik erhalten werden können.
KW - Core-shell nanoparticle (CSNP)
KW - X-ray photoelectron spectroscopy (XPS)
KW - Scanning transmission X-ray microscopy (STXM)
PY - 2022
DO - https://doi.org/10.18452/24312
SP - i
EP - 243
PB - Humboldt-Universität
CY - Berlin
AN - OPUS4-54991
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Reinmuth-Selzle, K.
A1 - Tchipilov, Teodor
A1 - Backes, A. T.
A1 - Tscheuschner, Georg
A1 - Tang, K.
A1 - Ziegler, K.
A1 - Lucas, K.
A1 - Pöschl, U.
A1 - Fröhlich-Nowoisky, J.
A1 - Weller, Michael G.
T1 - Determination of the protein content of complex samples by aromatic amino acid analysis, liquid chromatography-UV absorbance, and colorimetry
N2 - Fast and accurate determination of the protein content of a sample is an important and non-trivial task of many biochemical, biomedical, food chemical, pharmaceutical, and environmental research activities. Different methods of total protein determination are used for a wide range of proteins with highly variable properties in complex matrices. These methods usually work reasonably well for proteins under controlled conditions, but the results for non-standard and complex samples are often questionable. Here, we compare new and well-established methods, including traditional amino acid analysis (AAA), aromatic amino acid analysis (AAAA) based on the amino acids phenylalanine and tyrosine, reversed-phase liquid chromatography of intact proteins with UV absorbance measurements at 220 and 280 nm (LC-220, LC-280), and colorimetric assays like Coomassie Blue G-250 dye-binding assay (Bradford) and bicinchoninic acid (BCA) assay. We investigated different samples, including proteins with challenging properties, chemical modifications, mixtures, and complex matrices like air particulate matter and pollen extracts. All methods yielded accurate and precise results for the protein and matrix used for calibration. AAA, AAAA with fluorescence detection, and the LC-220 method yielded robust results even under more challenging conditions (variable analytes and matrices). These methods turned out to be well-suited for reliable determination of the protein content in a wide range of samples, such as air particulate matter and pollen.
KW - Air particulate matter
KW - Aromatic amino acid analysis
KW - Atmospheric aerosol
KW - Chemical protein modification
KW - Derivatization
KW - Nitration
KW - Nitrotyrosine
KW - LC-UV absorbance
KW - Pollen extract
KW - Protein quantification
KW - Protein test
KW - Kjeldahl
KW - Tyrosine
KW - Phenylalanine
KW - Hydrolysis
KW - Bradford
KW - BCA test
KW - 280 nm
KW - Air filter samples
KW - Fluorescence
KW - HPLC
KW - Chromatography
KW - Protein content
KW - 150th anniversary of BAM
KW - Topical collection: Analytical Methods and Applications in the Materials and Life Sciences
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545924
UR - https://pubmed.ncbi.nlm.nih.gov/35320366/
DO - https://doi.org/10.1007/s00216-022-03910-1
SP - 1
EP - 14
PB - Springer Nature Limited
CY - New York, Heidelberg
AN - OPUS4-54592
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Terborg, R.
A1 - Kim, K. J.
A1 - Hodoroaba, Vasile-Dan
T1 - Determination of Thin Film Thickness and Composition using Energy Dispersive EPMA
N2 - The thickness of thin films can be measured by various methods, e.g., profilometry, ellipsometry, atomic force microscopy (AFM), or X-ray reflectometry. For the additional determination of thin film composition, techniques like X-ray photoelectron spectroscopy (XPS) or mass spectrometry-based techniques can be used. An alternative non-destructive technique is electron probe microanalysis (EPMA). This method assumes a sample of homogenous (bulk) chemical composition, so that it cannot be usually applied to thin film samples. However, in combination with the thin film software StrataGEM, the thickness as well as the composition of such films on a substrate can be determined.
This has been demonstrated for FeNi on Si and SiGe on Al2O3 film systems. For both systems five samples with different elemental composition and a reference were produced and characterised by Korean research institute KRISS using inductively coupled plasma mass spectrometry (ICP-MS), Rutherford backscattering (RBS), and transmission electron microscopy (TEM). These samples were used for an international round robin test.
In 2021, a new and open-source thin film evaluation programme called BadgerFilm has been released. It can also be used to determine thin film composition and thickness from intensity ratios of the unknown sample and standards (k-ratios).
In this contribution, we re-evaluated the data acquired for the FeNi and SiGe systems using the BadgerFilm software package and compared the resulting composition and thickness with the results of the established StrataGEM software and other reference methods. With the current evaluation, the BadgerFilm software shows good agreement with the composition and thickness calculated by StrataGEM and as the reference values provided by the KRISS.
KW - Thin films
KW - Elemental composition
KW - Film thickness
KW - EPMA (Electron Probe Microanalysis)
PY - 2022
DO - https://doi.org/10.1017/S143192762200318X
VL - 28
IS - Suppl. 1
SP - 672
EP - 673
PB - Cambridge University Press
AN - OPUS4-55437
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Terborg, R.
A1 - Hodoroaba, Vasile-Dan
T1 - Determination of Thin Film Thickness and Composition using Energy Dispersive EPMA
N2 - Electron Probe Microanalysis (EPMA) provides a non-destructive approach in the dedicated thin film analysis mode with the commercial StrataGem software. Recently, the open-source programme BadgerFilm by Moy and Fournelle became available. Similarly to StrataGem, it is based on the algorithm of Pouchou and Pichoir and needs intensity ratios of the unknown sample and standards (k-values). We have evaluated the k-values measured for the FeNi and SiGe film systems using the BadgerFilm software package and compared the thickness and composition with the results obtained with the established StrataGem software and other reference methods. The thicknesses of the SiGe films obtained by the BadgerFilm software agree within 20% with the StrataGem and TEM results; the elemental compositions BadgerFilm-StrataGEM agree within 2% with one exception (9%).
T2 - Microscopy and Microanalysis 2022
CY - Portland, OR, USA
DA - 31.07.2022
KW - Thin films
KW - Thickness
KW - Elemental composition
KW - FeNi
KW - SiGe
KW - BadgerFilm
KW - Electron Probe Microanalysis (EPMA)
PY - 2022
AN - OPUS4-55522
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - C. Pardo Pérez, L.
A1 - Arndt, A.
A1 - Stojkovikj, S.
A1 - Y. Ahmet, I.
A1 - T. Arens,, J.
A1 - Dattila, F.
A1 - Wendt, R.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Davies, V.
A1 - Höflich, K.
A1 - Köhnen, E.
A1 - Tockhorn, P.
A1 - Golnak, R.
A1 - Xiao, J.
A1 - Schuck, G.
A1 - Wollgarten, M.
A1 - López, N.
A1 - T. Mayer, M.
T1 - Determining Structure-Activity Relationships in Oxide Derived CuSn Catalysts During CO2 Electroreduction Using X-Ray Spectroscopy
N2 - The development of earth-abundant catalysts for selective electrochemical CO2 conversion is a central challenge. Cu-Sn bimetallic catalysts can yield selective CO2 reduction toward either CO or formate. This study presents oxide-derived Cu-Sn catalysts tunable for either product and seeks to understand the synergetic effects between Cu and Sn causing these selectivity trends. The materials undergo significant transformations under CO2 reduction conditions, and their dynamic bulk and surface structures are revealed by correlating observations from multiple methods—X-ray absorption spectroscopy for in situ study, and quasi in situ X-ray photoelectron spectroscopy for surface sensitivity. For both types of catalysts, Cu transforms to metallic Cu0 under reaction conditions. However, the Sn speciation and content differ significantly between the catalyst types: the CO-selective catalysts exhibit a surface Sn content of 13 at. % predominantly present as oxidized Sn, while the formate-selective catalysts display an Sn content of ≈70 at. % consisting of both metallic Sn0 and Sn oxide species. Density functional theory simulations suggest that Snδ+ sites weaken CO adsorption, thereby enhancing CO selectivity, while Sn0 sites hinder H adsorption and promote formate production. This study reveals the complex dependence of catalyst structure, composition, and speciation with electrochemical bias in bimetallic Cu catalysts.
KW - Electrochemical CO2 conversion
KW - Cu catalysts
KW - X-ray absorption spectroscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547116
DO - https://doi.org/10.1002/aenm.202103328
SN - 1614-6832
VL - 12
IS - 5
SP - 2103328
PB - Wiley-VCH GmbH
AN - OPUS4-54711
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Tavernaro, Isabella
T1 - Development of amorphous silica particle based reference materials for surface functional group quantification
N2 - Functionalized nanomaterials (NM) with their unique size-dependent properties are of increasing relevance for current and future developments in various fields such as medical and pharmaceutical industry, computing, electronics or food and consumer products. The performance and safety of NM are determined by the sum of their intrinsic physicochemical properties.1 Besides other key parameters, the particle surface chemistry, which is largely controlled by the chemical nature and density of functional groups and ligands, must be considered for a better performance, stability, and processibility of NM, as well as their interaction with the environment. Thus, particle standards with well-designed surfaces and methods for functional group quantification can foster the sustainable development of functional and safe(r) NM.2 Here we provide a brief overview of the ongoing research in division Biophotonics to design tailored amorphous silica reference particles with bioanalytically relevant functional groups and ligands, for the development of standardized and validated surface functional group quantification methods.
T2 - Workshop NanoRiskSD project
CY - Berlin, Germany
DA - 09.06.2022
KW - Nanoparticle
KW - Surface analysis
KW - Silica
KW - Fluorescence
KW - Assay
PY - 2022
AN - OPUS4-55004
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Mair, Georg W.
T1 - Die BAM - mit einem aktuellen Aspekt der ZfP
N2 - Die BAM wird kurz mit ihren Eckdaten als Ganzes vorgestellt und dann der Einstieg in die besonderen Möglichkeiten der Versuchsplattform "Wasserstofftankstelle" erläutert. Nach kurzen Vorstellung der Struktur der Tankstelle wird erläutert, wie drei Methoden der ZfP für das Structural Health Monitoring in Verbindung mit KI zur Anwendung kommen werden.
T2 - Fachausschusssitzung Schallemissionsprüfung DGZfP
CY - Online meeting
DA - 10.03.2022
KW - 150 Jahre BAM
KW - Versuchsplattform
KW - H2-Tankstelle
KW - Ultraschall
KW - Schallemissionsanalyse
KW - Optische Fasern
KW - Künstliche Intelligenz
PY - 2022
AN - OPUS4-54606
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Dietz, Georg
A1 - Dumas, C.
A1 - Golle, U.
A1 - Melzer, C.
A1 - Mildenberger, H.
A1 - Orth, C.
A1 - Seifert, C. T.
A1 - Wintermann, Carsten
A1 - Ketelsen, T.
A1 - Hahn, Oliver
ED - Ketelsen, T.
ED - Hahn, Oliver
T1 - Die Sammlung der Niederländischen Zeichnungen in Weimar. Ein Handbuch
N2 - Die Klassik-Stiftung Weimar besitzt eine umfangreiche Sammlung niederländischer und flämischer Zeichnungen vom 15. bis 19. Jahrhundert. Im Rahmen des Forschungsprojektes »Kennerschaft heute« wurde der Bestand der über 1.500 Zeichnungen erstmals wissenschaftlich erschlossen. Das Handbuch führt anhand bedeutender Werkgruppen, darunter Zeichnungen von Lucas van Leyden, Dirck Vellert, Roelant Savery und Rembrandt, den Reichtum der Weimarer Sammlung vor Augen, die zum großen Teil auf die Sammelleidenschaft von Johann Wolfgang Goethe zurückgeht. Im Zentrum des Buches steht aber die Zusammenarbeit von traditioneller Stilkritik und naturwissenschaftlicher Materialanalyse. In zwölf Fallbeispielen wird die Notwendigkeit einer methodischen Neuausrichtung der Kennerschaft darlegt. Einen Schwerpunkt der Untersuchungen bildet hierbei das große Konvolut an Zeichnungen von Rembrandt und seinen Schülern, das erstmals systematisch auf die verwendeten Zeichenmaterialien und Papiere untersucht wird.
KW - Archäometrie
KW - Zeichnungen
KW - Papier
KW - Zeichenmaterialien
KW - Rembrandt
PY - 2022
SN - 978-3-95498-715-3
SP - 1
EP - 312
PB - Sandstein Verlag
CY - Dresden
AN - OPUS4-56720
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Stargardt, Patrick
T1 - Dielectric properties of plasma sprayed coatings for insulation application
N2 - Thermal spraying provides a rapid method for additive deposition of various ceramics as electrical insulation in applications where polymers are not suitable. New applications in complex shaped additive manufactured metal parts are emerging for example in large scale electrical devices. Microstructural and dielectric evaluation of coatings is crucial to the employment of such free-form processes. The properties and microstructure of the plasma sprayed alumina coatings are compared with dense reference samples of the same powder produced by spark plasma sintering (SPS). To obtain dense bulk samples from the coarse alumina powder for spray coating, SPS is used.
Samples are fabricated by atmospheric plasma spraying (APS) of commercially available alumina powder (d50 = 33 µm) on copper substrates and by SPS of the same powder. Microstructure and porosity were analyzed by optical microscopy and scanning electron microscopy (SEM). Phase compositions were determined by X-ray diffraction (XRD). Dielectric properties such as DC resistance, dielectric strength, dielectric loss, and relative permittivity were determined according to the standards. The microstructure and dielectric properties of the coating and bulk material are compared to assess whether the coating is suitable for use in electrical insulation application.
T2 - Ceramics in Europe 2022
CY - Krakow, Poland
DA - 10.07.2022
KW - Dielectric characterization
KW - Atmospheric plasma spraying
KW - Spark plasma sintering
KW - Electrical insulation
PY - 2022
AN - OPUS4-55328
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Anderhalten, L.
A1 - Silva, R. V.
A1 - Morr, A.
A1 - Wang, S.
A1 - Smorodchenko, A.
A1 - Saatz, Jessica
A1 - Traub, Heike
A1 - Mueller, S.
A1 - Boehm-Sturm, P.
A1 - Rodriguez-Sillke, Y.
A1 - Kunkel, D.
A1 - Hahndorf, J.
A1 - Paul, F.
A1 - Taupitz, M.
A1 - Sack, I.
A1 - Infante-Duarte, C.
T1 - Different Impact of Gadopentetate and Gadobutrol on Inflammation-Promoted Retention and Toxicity of Gadolinium Within the Mouse Brain
N2 - Objectives: Using a murine model of multiple sclerosis, we previously showed that repeated administration of gadopentetate dimeglumine led to retention of gadolinium (Gd) within cerebellar structures and that this process was enhanced with inflammation. This study aimed to compare the kinetics and retention profiles of Gd in inflamed and healthy brains after application of the macrocyclic Gd-based contrast agent (GBCA) gadobutrol or the linear GBCA gadopentetate. Moreover, potential Gd-induced neurotoxicity was investigated in living hippocampal slices ex vivo.
Materials and Methods: Mice at peak of experimental autoimmune encephalomyelitis (EAE; n = 29) and healthy control mice (HC; n = 24) were exposed to a cumulative dose of 20 mmol/kg bodyweight of either gadopentetate dimeglumine or gadobutrol (8 injections of 2.5 mmol/kg over 10 days). Magnetic resonance imaging (7 T) was performed at baseline as well as at day 1, 10, and 40 post final injection (pfi) of GBCAs. Mice were sacrificed after magnetic resonance imaging and brain and blood Gd content was assessed by laser ablation-inductively coupled plasma (ICP)-mass spectrometry (MS) and ICP-MS, respectively. In addition, using chronic organotypic hippocampal slice cultures, Gd-induced neurotoxicity was addressed in living brain tissue ex vivo, both under control or inflammatory (tumor necrosis factor α [TNF-α] at 50 ng/μL) conditions.
Results: Neuroinflammation promoted a significant decrease in T1 relaxation times after multiple injections of both GBCAs as shown by quantitative T1 mapping of EAE brains compared with HC. This corresponded to higher Gd retention within the EAE brains at 1, 10, and 40 days pfi as determined by laser ablation-ICP-MS. In inflamed cerebellum, in particular in the deep cerebellar nuclei (CN), elevated Gd retention was observed until day 40 after last gadopentetate application (CN: EAE vs HC, 55.06 ± 0.16 μM vs 30.44 ± 4.43 μM). In contrast, gadobutrol application led to a rather diffuse Gd content in the inflamed brains, which strongly diminished until day 40 (CN: EAE vs HC, 0.38 ± 0.08 μM vs 0.17 ± 0.03 μM). The analysis of cytotoxic effects of both GBCAs using living brain tissue revealed an elevated cell death rate after incubation with gadopentetate but not gadobutrol at 50 mM. The cytotoxic effect due to gadopentetate increased in the presence of the inflammatory mediator TNF-α (with vs without TNF-α, 3.15% ± 1.18% vs 2.17% ± 1.14%; P = 0.0345).
Conclusions: In the EAE model, neuroinflammation promoted increased Gd retention in the brain for both GBCAs. Whereas in the inflamed brains, efficient clearance of macrocyclic gadobutrol during the investigated time period was observed, the Gd retention after application of linear gadopentetate persisted over the entire observational period. Gadopentetate but not gadubutrol appeared to be neurotoxic in an ex vivo paradigm of neuronal inflammation.
KW - Imaging
KW - ICP-MS
KW - Gadolinium
KW - Contrast agent
KW - Laser ablation
KW - Brain
KW - Multiple sclerosis
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546910
DO - https://doi.org/10.1097/RLI.0000000000000884
SN - 0020-9996/22/0000–0000
VL - 57
IS - 10
SP - 677
EP - 688
PB - Wolters Kluwer N.V.
CY - Alphen aan den Rijn, The Netherlands
AN - OPUS4-54691
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Serrano-Munoz, Itziar
A1 - Fernández, R.
A1 - Saliwan Neumann, Romeo
A1 - González-Doncel, G.
A1 - Bruno, Giovanni
T1 - Dislocation substructures in pure aluminium after creep deformation as studied by electron backscatter diffraction
N2 - In the present work, electron backscatter diffraction was used to determine the microscopic dislocation structures generated during creep (with tests interrupted at the steady state) in pure 99.8% aluminium. This material was investigated at two different stress levels, corresponding to the power-law and power-law breakdown regimes. The results show that the formation of subgrain cellular structures occurs independently of the crystallographic orientation. However, the density of these cellular structures strongly depends on the grain crystallographic orientation with respect to the tensile axis direction, with <111> grains exhibiting the highest densities at both stress levels. It is proposed that this behaviour is due to the influence of intergranular stresses, which is different in <111> and <001> grains.
KW - Creep
KW - Pure aluminium
KW - Electron backscatter diffraction
KW - Cellular structures
KW - Power law and power-law breakdown
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552003
DO - https://doi.org/10.1107/S1600576722005209
SN - 0021-8898
SN - 1600-5767
VL - 55
SP - 860
EP - 869
PB - Wiley-Blackwell
CY - Copenhagen
AN - OPUS4-55200
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Cakir, Cafer Tufan
A1 - Radtke, Martin
A1 - Haider, M. Bilal
A1 - Emmerling, Franziska
A1 - F. M. Oliveira, P.
A1 - Michalchuk, Adam
T1 - Dispersive x-ray absorption spectroscopy for time-resolved in situ monitoring of mechanochemical reactions
N2 - X-ray absorption spectroscopy (XAS) provides a unique, atom-specific tool to probe the electronic structure of solids. By surmounting long-held limitations of powder-based XAS using a dynamically averaged powder in a Resonant Acoustic Mixer (RAM), we demonstrate how time-resolved in situ (TRIS) XAS provides unprecedented detail of mechanochemical synthesis. The use of a custom-designed dispersive XAS (DXAS) setup allows us to increase the time resolution over existing fluorescence measurements from ∼15 min to 2 s for a complete absorption spectrum. Hence, we here establish TRIS-XAS as a viable method for studying mechanochemical reactions and sampling reaction kinetics. The generality of our approach is demonstrated through RAM-induced (i) bottom-up Au nanoparticle mechanosynthesis and (ii) the synthesis of a prototypical metal organic framework, ZIF-8. Moreover, we demonstrate that our approach also works with the addition of a stainless steel milling ball, opening the door to using TRIS-DXAS for following conventional ball milling reactions. We expect that our TRIS-DXAS approach will become an essential part of the mechanochemical tool box.
KW - In situ studies
KW - Dipsersive XAS
KW - Mechanochemistry
KW - Time-resolved
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567659
DO - https://doi.org/10.1063/5.0130673
SN - 1089-7690
VL - 157
IS - 21
SP - 1
EP - 12
PB - American Institute of Physics
CY - Melville, NY
AN - OPUS4-56765
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Monks, M.-J.
A1 - Würth, Christian
A1 - Kemnitz, Erhard
A1 - Resch-Genger, Ute
T1 - Dopant ion concentration-dependent upconversion luminescence of cubic SrF2:Yb3+, Er3+ nanocrystals prepared by a fluorolytic sol–gel method
N2 - A fluorolytic sol–gel method was used for the fast and simple synthesis of small cubic-phase SrF2:Yb3+, Er3+ upconversion (UC) nanocrystals (UCNC) of different composition at room temperature. Systematic studies of the crystal phase and particle size of this Yb3+,Er3+-concentration series as well as excitation power density (P)-dependent UC luminescence (UCL) spectra, UCL quantum yields (ΦUCL), and UCL decay kinetics yielded maximum UCL performance for doping amounts of Yb3+ of 13.5% and Er3+ of 1.3% in the studied doping and P-range (30–400 W cm−2). Furthermore, ΦUCL were determined to be similar to popular β-NaYF4:Yb3+,Er3+. The relative spectral UCL distributions revealed that all UCNC show a strong red emission in the studied doping and P-range (30–400 W cm−2) and suggest that the UCL quenching pathway for unshelled cubic-phase SrF2:Yb3+,Er3+ UCNC differs from the commonly accepted population and depopulation pathways of β-NaYF4:Yb3+,Er3+ UCNC. In SrF2:Yb3+,Er3+ UCNC the 4S3/2 →
4I13/2 transition exhibits a notably stronger sensitivity towards P and reveals increasing values for decreasing Yb3+–Yb3+ distances while the 4I9/2 → 4I15/2 transition is significantly less affected by P and energy migration facilitated UCL quenching. These results emphasize the complexity of the UC processes and the decisive role of the crystal phase and symmetry of the host lattice on the operative UCL quenching mechanism in addition to surface effects. Moreover, the room temperature UCNC synthesis enabled a systematic investigation of the influence of the calcination temperature on the crystal phase of powder-UCNC and the associated UCL properties. Calcination studies of solid UCNC of optimized doping concentration in the temperature range of 175 °C and 800 °C showed the beneficial influence of temperature-
induced healing of crystal defects on UCL and the onset of a phase separation connected with the oxygenation of the lanthanide ions at elevated temperature. This further emphasizes the sensitivity of the UC process to the crystal phase and quality of the host matrix.
KW - Upconversion nanoparticle
KW - Lanthanide
KW - Photophysics
KW - Synthesis
PY - 2022
DO - https://doi.org/10.1039/d2nr02337g
SP - 1
EP - 10
PB - Royal Society of Chemistry
AN - OPUS4-55364
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Garrido, E.
A1 - Climent Terol, Estela
A1 - Marcos, M. D.
A1 - Sancenón, F.
A1 - Rurack, Knut
A1 - Martínez-Máñez, R.
T1 - Dualplex lateral flow assay for simultaneous scopolamine and "cannibal drug" detection based on receptor-gated mesoporous nanoparticles
N2 - We report herein the design of a strip-based rapid test utilizing bioinspired hybrid nanomaterials for the in situ and at site detection of the drug scopolamine (SCP) using a smartphone for readout, allowing SCP identification in diluted saliva down to 40 nM in less than 15 min. For this purpose, we prepared a nanosensor based on mesoporous silica nanoparticles loaded with a fluorescent reporter (rhodamine B) and functionalized with bethanechol, a potent agonist of recombinant human muscarinic acetylcholine receptor M2 (M2-AChR). M2-AChR interaction with the anchored bethanechol derivative leads to capping of the pores. The sensing mechanism relies on binding of SCP to M2-AChR resulting in pore opening and delivery of the entrapped rhodamine B reporter. Moreover, the material was incorporated into strips for lateral-flow assays coupled to smartphone readout, giving fast response time, good selectivity, and exceptional sensitivity. In an attempt to a mobile analytical test system for law enforcement services, we have also developed a dualplex lateral flow assay for SCP and 3,4-methylenedioxypyrovalerone (MDPV) also known as the so-called “cannibal drug”.
KW - Rapid tests
KW - Vor-Ort-Analytik
KW - Lateral Flow Assays
KW - Scopolamine
KW - Gesteuerte Freisetzung
KW - Cannibal Drug
PY - 2022
DO - https://doi.org/10.1039/d2nr03325a
SP - 1
EP - 9
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-55744
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 - Arinchtein, A.
A1 - Ye, M.-Y.
A1 - Yang, Q.
A1 - Kreyenschulte, C.
A1 - Wagner, Andreas
A1 - Frisch, M.
A1 - Brückner, A.
A1 - Kondratenko, E.
A1 - Kraehnert, R.
T1 - Dynamics of Reaction-Induced Changes of Model-Type Iron Oxide Phases in the CO2-Fischer-Tropsch-Synthesis
N2 - Iron-based catalysts are employed in CO2-FTS due to their ability to convert CO2 into CO in a first step and their selectivity towards higher hydrocarbons in a second CO hydrogenation step. According to the literature, iron carbides represent the active phase for hydrocarbon formation and are claimed to emerge in the presence of CO. We propose nanostructured FeOx films as model systems to assess information about the complex phase transformations during CO2-FTS. Mesoporous hematite, ferrihydrite, maghemite, maghemite/magnetite films were exposed to CO2-FTS atmospheres at 20 bar and 300°C. Up to three distinct phases were observed depending on the timeon-stream (TOS): a sintered maghemite/magnetite phase, a carbidic core-shell structure, and a low-crystalline, needle-type oxide phase. Our findings indicate that the formation of an intermediary maghemite/magnetite phase, predominant after short TOS (30 h), precedes the evolution of the carbide phase.
Yet, even after prolonged TOS (185 h), no full conversion into a bulk carbide is observed.
KW - Nanostructured FeOx films
KW - CO2
KW - Scanning Auger Spectroscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549709
DO - https://doi.org/10.1002/cctc.202200240
SN - 1867-3880
VL - 14
IS - 14
SP - 1
EP - 11
PB - Wiley-VCH
AN - OPUS4-54970
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stawski, Tomasz
A1 - Van Driessche, A. E. S.
T1 - Editorial for special issue "Formation of sulfate minerals in natural and industrial environments"
N2 - Sulfate is abundant in the environment and, as a result, sulfate-containing minerals constitute a large and important focus of research. These minerals play an important role in many geochemical and industrial processes, including the sulfur cycle, the construction industry (e.g., plaster of Paris), fault tectonics, acid mine drainage, and even rare biominerals. Important to note are the abundant amounts of sulfate (minerals) located on the surface of Mars, and in meteorites, extending the relevance of this mineral group beyond the realm of our planet. In geological systems, sulfate minerals such as barite are also important for indicating certain sedimentation environments. In this regard, sulfate deposits can be used to evaluate the redox state of ancient oceans during early Earth time periods.
KW - Calcium sulfate
KW - Sulfates
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546794
DO - https://doi.org/10.3390/min12030299
SN - 2075-163X
VL - 12(3)
IS - Special issue "Formation of sulfate minerals in natural and industrial environments"
SP - 1
EP - 3
PB - MDPI
CY - Basel
AN - OPUS4-54679
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Resch-Genger, Ute
A1 - Meermann, Björn
A1 - Koch, Matthias
A1 - Weller, Michael G.
T1 - Editorial: Analytical methods and applications in materials and life sciences
N2 - Current trends in materials and life sciences are flanked by the need to push detection limits to single molecules or single cells, enable the characterization of increasingly complex matrices or sophisticated nanostructures, speed up the time of analysis, reduce instrument complexity and costs, and improve the reliability of data. This requires suitable analytical tools such as spectroscopic, separation and imaging techniques, mass spectrometry, and hyphenated techniques as well as sensors and their adaptation to application-specific challenges in the environmental, food, consumer product, health sector, nanotechnology, and bioanalysis. Increasing concerns about health threatening known or emerging pollutants in drinking water, consumer products, and food and about the safety of nanomaterials led to a new awareness of the importance of analytical sciences. Another important driver in this direction is the increasing demand by legislation, particularly in view of the 17 sustainable development goals by the United Nations addressing clean energy, industry, and innovation, sustainable cities, clean water, and responsible consumption and production. In this respect, also the development of analytical methods that enable the characterization of material flows in production processes and support recycling concepts of precious raw materials becomes more and more relevant. In the future, this will provide the basis for greener production in the chemical industry utilizing recycled or sustainable starting materials.
This makes analytical chemistry an essential player in terms of the circular economy helping to increase the sustainability of production processes. In the life sciences sector, products based on proteins, such as therapeutic and diagnostic antibodies, increase in importance. These increasingly biotechnologically produced functional biomolecules pose a high level of complexity of matrix and structural features that can be met only by highly advanced methods for separation, characterization, and detection. In addition, metrological traceability and target definition are still significant challenges for the future, particularly in the life sciences.
However, innovative reference materials as required for the health and food sector and the characterization of advanced materials can only be developed when suitable analytical protocols are available. The so-called reproducibility crisis in sciences underlines the importance of improved measures of quality control for all kinds of measurements and material characterization. This calls for thorough method validation concepts, suitable reference materials, and regular interlaboratory comparisons of measurements as well as better training of scientists in analytical sciences.
The important contribution of analytical sciences to these developments is highlighted by a broad collection of research papers, trend articles, and critical reviews from these different application fields. Special emphasis is dedicated to often-overlooked quality assurance and reference materials.
T2 - 150 years BAM: Science with impact
CY - Berlin, Germany
DA - 01.01.2021
KW - Analysis
KW - Life sciences
KW - Analytical sciences
KW - Quality assurance
KW - Reference material
KW - Fluorescence
KW - Nanoparticle
KW - Sensor
KW - Material sciences
KW - Pollutant
KW - Environment
KW - Method
KW - Limit of detection
KW - 150th anniversary
KW - ABC
KW - BAM
KW - Collection
KW - Editorial
KW - Special issue
KW - Bundesanstalt für Materialforschung und -prüfung
KW - Jahrestag
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550720
DO - https://doi.org/10.1007/s00216-022-04082-8
SN - 1618-2642
SN - 1618-2650
VL - 414
IS - Topical collection: Analytical methods and applications in the materials and life sciences
SP - 4267
EP - 4268
PB - Springer
CY - Berlin
AN - OPUS4-55072
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cappella, Brunero
A1 - Spaltmann, Dirk
A1 - Gee, M.
T1 - Editorial: Tribology and Atomic Force Microscopy - Towards Single Asperity Contact
N2 - The concept behind this Research Topic (RT) was to collect works, in which Atomic Force Microscopy (AFM) techniques are employed to study tribological phenomena and to push the resolution of measurements towards single asperity contact. Thanks to the direct determination of sample height with sub-nanometer resolution and the possibility of measuring local friction, AFM can be employed after a tribotest to detect topography and friction changes at the nanometer scale. Recently, efforts are being expended to use AFM cantilevers as tribometers, i.e., as probes altering the volume of suitable samples, thereby measuring tip and/or sample wear and friction at the nano/microscale. Thus, single asperity contact, friction, and wear can be investigated. Since friction and wear at the macroscale are the result of asperities interactions, such experiments are of great importance for better understanding of tribological processes.
KW - Nanotribology
KW - Friction
KW - Wear
KW - Single asperity
KW - AFM
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571037
DO - https://doi.org/10.3389/fmech.2022.853934
SN - 2297-3079
VL - 8
SP - 1
EP - 2
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-57103
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nasr Esfahani, M.
A1 - Zare Pakzad, S.
A1 - Li, T.
A1 - Li, X.
A1 - Tasdemir, Z.
A1 - Wollschläger, Nicole
A1 - Leblebici, Y.
A1 - Erdem Alaca, B.
T1 - Effect of Native Oxide on Stress in Silicon Nanowires: Implications for Nanoelectromechanical Systems
N2 - Understanding the origins of intrinsic stress in Si nanowires (NWs) is crucial for their successful utilization as transducer building blocks in next-generation, miniaturized sensors based on anoelectromechanical systems (NEMS). With their small size leading to ultrahigh-resonance frequencies and extreme surface-to-volume ratios, silicon NWs raise new opportunities regarding sensitivity, precision, and speed in both physical and biochemical sensing. With silicon optoelectromechanical properties strongly dependent on the level of NW intrinsic stress, various studies have been devoted to the measurement of such stresses generated, for example, as a result of harsh fabrication processes. However, due to enormous NW surface area, even the native oxide that is conventionally considered as a benign surface condition can cause significant stresses. To address this issue, a combination of nanomechanical characterization and atomistic simulation approaches is developed. Relying only on low-temperature processes, the fabrication approach yields monolithic NWs with optimum boundary conditions, where NWs and support architecture are etched within the same silicon crystal. Resulting NWs are characterized by transmission electron microscopy and micro-Raman spectroscopy. The interpretation of results is carried out through molecular dynamics simulations with ReaxFF potential facilitating the incorporation of humidity and temperature, thereby providing a close replica of the actual oxidation environment - in contrast to previous dry oxidation or self-limiting thermal oxidation studies. As a result, consensus on significant intrinsic tensile stresses on the order of 100 MPa to 1 GPa was achieved as a function of NW critical dimension and aspect ratio. The understanding developed herein regarding the role of native oxide played in the generation of NW intrinsic stresses is important for the design and development of silicon-based NEMS.
KW - Nanoelectromechanical systems (NEMS)
KW - Silicon nanowires
KW - Native oxide
KW - Intrinsic stress
KW - Raman spectroscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560471
DO - https://doi.org/10.1021/acsanm.2c02983
SN - 2574-0970
VL - 5
SP - 13276
EP - 13285
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-56047
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wu, Dejian
A1 - Schmidt, Martin
A1 - Krietsch, Arne
A1 - Krause, U.
T1 - Effect of oxygen concentration, inert gas and CH4/H2 addition on the minimum ignition energy of coal dusts
N2 - MIKE III apparatus tests were conducted to investigate the minimum ignition energy (MIE) of coal dusts in air and O2/CO2 atmospheres with and without small amount of CH4/H2. The O2 mole fraction (XO2) in the gas mixtures varied from 21% to 50% with the CH4/H2 mole fraction from 0 to 2%. Experimental result showed that MIE of coal dusts significantly decreases even by three orders of magnitude in mJ with increasing XO2 and the addition of CH4/H2. Compared with CH4, H2 had a relatively strong promotion effect on the spark ignition of coal dusts. The inhibiting effect of CO2 was found to be much stronger than N2, but this inhibiting effect of CO2 could be eliminated by 9% increment of XO2. The effect on MIE of coal dusts thus followed by the order: 9% increment of XO2 > CO2 replacing N2 > 2% CH4 or H2 addition. Moreover, two empirical models were used to estimate the MIE of hybrid dust-gas mixture (HMIE), and the results showed that calculated data can well reflect the promoting effect of elevated XO2 and flammable gas addition, and the inhibiting effect of inert gas
KW - Ignition energy
KW - Hybrid mixture
KW - Oxygen rich
KW - Inerting effect
KW - Empirical model
PY - 2022
DO - https://doi.org/10.1016/j.jlp.2022.104772
SN - 0950-4230
VL - 77
SP - 1
EP - 10
PB - Elsevier Ltd.
AN - OPUS4-55888
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Fellinger, Tim-Patrick
T1 - Effects of Acid Activation via Sol-Gel Chemistry towards Nitrogen-Doped Carbon Structure
N2 - Porous carbon materials are known for their applicability in important areas such as sorption, catalysis and electrochemistry (e.g. fuel cell catalysts, supercapacitor or battery electrodes). It was shown that nitrogen doped carbons (NDCs) act as an inexpensive and highly active non-metal catalyst in the oxygen reduction reaction (ORR), with the potential to reach performances of practical need one day. A key strategy towards improvement for this aim comprises the generation of advantageous porosity, which typically means high surface area and mass transport pores as well as the control over the chemistry of catalytically active sites. My group is developing novel sol-gel type strategies that are using molten salts or molten acids as unconventional reaction medium for the porogenesis in doped carbons, thereby revisiting classic activation techniques.[1,2] Carbon materials with extra high surface area of ~2800 m2 g- 1 and pore volumes, up to four times as high as in commercial activated carbons, are obtained.[3] It turns out that the meso- and macrostructure is generated by means of phase separation rather than leaching reactions. However, chemical reactions between the carbon precursor and the melt are also involved. The salt cations Mg2+ and Zn2+ act as template ions, which results in metal coordination sites, embedded into the carbon structure.[4,5] The imprinted structure may be utilized as catalytically active site by performing ion-exchange reactions. The novel preparation strategy towards highly active electrocatalysts will be presented for Mg and Zn and further discussed for lighter elements.
T2 - International Sol-Gel Conference 2022
CY - Lyon, France
DA - 24.06.2022
KW - Sol-Gel-Carbonization
KW - Boron-Nitrogen-Doped Carbon
PY - 2022
AN - OPUS4-61958
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radnik, Jörg
A1 - Hodoroaba, Vasile-Dan
T1 - Elemental Composition and Thickness Determination of Thin Films by Electron Probe Microanalysis (EPMA)
N2 - microscopy (AFM), or X-ray reflectometry. For the additional determination of thin film composition, techniques like X-ray photoelectron spectroscopy (XPS) or mass spectrometry-based techniques can be used. An alternative non-destructive technique is electron probe microanalysis (EPMA). This method assumes a sample of homogenous (bulk) chemical composition, so that it cannot be usually applied to thin film samples. However, in combination with the thin film software StrataGEM, the thickness as well as the composition of such films on a substrate can be determined.
This has been demonstrated for FeNi on Si and SiGe on Al2O3 film systems. For both systems five samples with different elemental composition and a reference were produced and characterised by Korean research institute KRISS using inductively coupled plasma mass spectrometry (ICP-MS), Rutherford backscattering (RBS), and transmission electron microscopy (TEM). These samples were used for an international round robin test.
In 2021, a new and open-source thin film evaluation programme called BadgerFilm has been released. It can also be used to determine thin film composition and thickness from intensity ratios of the unknown sample and standards (k-ratios).
In this contribution, we re-evaluated the data acquired for the FeNi and SiGe systems using the BadgerFilm software package and compared the resulting composition and thickness with the results of the established StrataGEM software and other reference methods. With the current evaluation, the BadgerFilm software shows good agreement with the composition and thickness calculated by StrataGEM and as the reference values provided by the KRISS.
T2 - ECASIA 2022
CY - Limerick, Ireland
DA - 29.05.2022
KW - Thin films
KW - Electron Probe Microanalysis
KW - Interlaboratory Comparisons
PY - 2022
AN - OPUS4-54963
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hertwig, Andreas
T1 - ELENA: a European project for electrical nanoscale metrology in industry
N2 - A competitive advantage in the semiconductors industry is gained through the exploitation of new materials and processes, translating into improved components’ performances. This requires a metrological infrastructure allowing reliable nanoscale characterisation of new materials and devices, particularly in terms of their electrical parameters and properties. Traceability and reliability of nanoscale measurements stand as a major challenge for electrical properties (i.e. resistance, impedance) using conductive atomic force microscopy (C-AFM) and scanning microwave microscopy (SMM) techniques. The non-destructive analysis nature of these two methods is of paramount importance for the characterization of devices and components. However, the state of the art still lacks established measurement protocols, easy to use reference standards, well-defined best practice guides and easy to use 3D models to assess environmental and external stimulation effects. Moreover, costly instrumentation, particularly for high-frequency measurements, still hinders efficient advancements in these directions.
ELENA is a 3-years European project that aims at bringing solutions to the aforementioned difficulties. To achieve this goal, the project uses a combination of nanoscale electrodynamic scanning probe methods in combination with optical tools such as spectroscopic ellipsometry on several lateral length scales to determine the electrical properties of layers and small structures.
T2 - ICSE-9: The 9th International Conference on Spectroscopic Ellipsometry
CY - Beijing, China
DA - 2022-05-21
KW - Imaging Ellipsometry
KW - Electrical thin layers
KW - Scanning Probe methods
KW - Hybrid metrology
PY - 2022
AN - OPUS4-55464
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hodoroaba, Vasile-Dan
T1 - EMPIR nPSize - Improved Traceability Chain of Nanoparticle Size Measurement - What nPSize can offer to ISO/TC 229?
N2 - The main outcomes of the EMPIR project nPSize are presented and the suitability of the new capabilities, e.g. reference materials, sample preparation protocols, measurement procedures, and data analysis, to be standardized and implemented in accredited analytical laboratories is discussed. Complementation and/or filling gaps of published and ongoing standardisation projects on size, shape and number concentration measurements under ISO/TC 229/JWG 2 are offered.
The two VAMAS inter-laboratory comparisons resulted from the nSPize project and just started under TWA 34 Nanoparticle Populations (Projects #15 and #16) of bipyramidal TiO2 anatase and bimodal SiO2 nanoparticles are presented in detail.
T2 - Interim Meeting of ISO/TC 229 Nanotechnologies - Strategy and Metrology Group
CY - Online meeting
DA - 09.05.2022
KW - Nanoparticles
KW - Particle size distribution
KW - Inter-laboratory comparison
KW - Electron microscopy
KW - AFM
KW - SAXS
KW - ISO/TC229
PY - 2022
AN - OPUS4-54819
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ewert, U.
A1 - Jaenisch, Gerd-Rüdiger
A1 - Schumacher, David
A1 - Bircher, B.
A1 - Meli, F.
A1 - Deresch, A.
T1 - EMPIR-Projekt NanoXSpot: Neue Normentwürfe für die Brennfleckmessung an Röntgenröhren im Makro-, Mikro- und Nanometerbereich für Hersteller und Anwender
N2 - Im Rahmen des EMPIR-Projektes NanoXSpot (Nanometre X-ray Focal Spot Measurement) werden rückführbare Messverfahren zur Bestimmung der Brennfleckgröße und -form von Röntgenröhren im Bereich von 100 nm bis 10 mm entwickelt, welche die Grundlage für die Erarbeitung mehrerer Normentwürfe bilden. Diese werden 2022 parallel bei ISO TC 135 (NDT) SC 5 (RT) und CEN TC 138 (NDT) WG 1 (RT) eingereicht. Entsprechende Normen werden auch bei ASTM vorgestellt. Die Norm EN 12543-4 (Kantenmethode) wird umgeschrieben für die Messung von Brennflecken von 1 μm – 10 mm durch Auswertung von Loch- oder Scheibenaufnahmen. Der im Rahmen des NanoXSpot-Projektes neu entwickelte NxS-Testkörper ist geeignet für den Bereich von 1 μm – 100 μm. Von 100 μm bis 10 mm können ASTM-Lochtestkörper verwendet werden, die bereits bei ASTM E 1165 beschrieben sind. Neu ist die Anwendung eines CT-Algorithmus zur Rekonstruktion der Brennflecke, um Lochblenden-basierte Brennfleckkameras, insbesondere im Bereich unter 100 μm, zu ersetzen. Ein neuer Normteil, EN 12543-6, wurde entworfen, um die Brennfleckmessung im Bereich 100 nm – 20 μm mit hoher Genauigkeit zu ermöglichen. Verschiedene Strichgruppen-Testkörper kommen hier zum Einsatz. Das sind die JIMAPrüfkörper, ein neuer Hochkontrast-Strichgruppentestkörper von YXLON (HiCo) und der neu entwickelte Testkörper NxS. Diese werden vorgestellt. Die Messprozedur für Röhrenhersteller wird auf einer numerischen Fit-Prozedur basieren, die über einen Ringversuch im Projekt validiert wurde. Beide Normen benötigen numerische Auswertealgorithmen zur korrekten Anwendung, die als kommerzielle Software und Public Domain – Software verfügbar gemacht werden. Es wird über die zu erwartenden Standardprozeduren und die erforderliche Hardware zur Anwendung der Normen informiert.
T2 - DGZfP-Jahrestagung
CY - Kassel, Germany
DA - 23.05.2022
KW - Röntgenröhre
KW - Brennfleckmessung
KW - Normung
PY - 2022
AN - OPUS4-56100
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ewert, U.
A1 - Jaenisch, Gerd-Rüdiger
A1 - Schumacher, David
A1 - Bircher, B.
A1 - Meli, F.
A1 - Deresch, A.
T1 - EMPIR-Projekt NanoXSpot: Neue Normentwürfe für die Brennfleckmessung an Röntgenröhren im Makro-, Mikro- und Nanometerbereich für Hersteller und Anwender
N2 - Im Rahmen des EMPIR-Projektes NanoXSpot (Nanometre X-ray Focal Spot Measurement) werden rückführbare Messverfahren zur Bestimmung der Brennfleckgröße und -form von Röntgenröhren im Bereich von 100 nm bis 10 mm entwickelt, welche die Grundlage für die Erarbeitung mehrerer Normentwürfe bilden. Diese werden 2022 parallel bei ISO TC 135 (NDT) SC 5 (RT) und CEN TC 138 (NDT) WG 1 (RT) eingereicht. Entsprechende Normen werden auch bei ASTM vorgestellt. Die Norm EN 12543-4 (Kantenmethode) wird umgeschrieben für die Messung von Brennflecken von 1 μm – 10 mm durch Auswertung von Loch- oder Scheibenaufnahmen. Der im Rahmen des NanoXSpot-Projektes neu entwickelte NxS-Testkörper ist geeignet für den Bereich von 1 μm – 100 μm. Von 100 μm bis 10 mm können ASTM-Lochtestkörper verwendet werden, die bereits bei ASTM E 1165 beschrieben sind. Neu ist die Anwendung eines CT-Algorithmus zur Rekonstruktion der Brennflecke, um Lochblenden-basierte Brennfleckkameras, insbesondere im Bereich unter 100 μm, zu ersetzen. Ein neuer Normteil, EN 12543-6, wurde entworfen, um die Brennfleckmessung im Bereich 100 nm – 20 μm mit hoher Genauigkeit zu ermöglichen.
Verschiedene Strichgruppen-Testkörper kommen hier zum Einsatz. Das sind die JIMAPrüfkörper, ein neuer Hochkontrast-Strichgruppentestkörper von YXLON (HiCo) und der neu entwickelte Testkörper NxS. Diese werden vorgestellt. Die Messprozedur für Röhrenhersteller wird auf einer numerischen Fit-Prozedur basieren, die über einen Ringversuch im Projekt validiert wurde. Beide Normen benötigen numerische Auswertealgorithmen zur korrekten Anwendung, die als kommerzielle Software und Public Domain – Software verfügbar gemacht werden. Es wird über die zu erwartenden Standardprozeduren und die erforderliche Hardware zur Anwendung der Normen informiert.
T2 - DGZfP-Jahrestagung
CY - Kassel, Germany
DA - 23.05.2022
KW - Röntgenröhre
KW - Brennfleckmessung
KW - Normung
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561029
SP - 1
EP - 10
AN - OPUS4-56102
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schumacher, David
A1 - Jaenisch, Gerd-Rüdiger
A1 - Ewert, U.
A1 - Bircher, B.
A1 - Meli, F.
A1 - Sofiienko, A.
A1 - Steffen, J. P.
A1 - Deresch, A.
T1 - EMPIR-Projekt NanoXSpot: Ringversuch zur Untersuchung der neu entwickelten Methoden für die Brennfleckmessung an Röntgenröhren im Mikro- und Nanometerbereich
N2 - Im Rahmen des EMPIR-Projektes NanoXSpot (Nanometre X-Ray Focal Spot Measurement) werden rückführbare Messverfahren zur Bestimmung der Brennfleckgröße und -form von Röntgenröhren mit Submikrometerauflösung (100 nm – 20 μm) entwickelt, die die Grundlage für die Erarbeitung eines Standardentwurfes bilden. Der Standardentwurf wird bei CEN TC 138 (Non-destructive testing) WG 1 (Radiographic testing) eingereicht und mit ISO und ASTM harmonisiert. Zur Untersuchung der entwickelten Methoden (Brennfleck-CT, Fit-Prozedur für Strichgruppenkörper) und des im Projekt NanoXSpot neu entworfenen Testkörpers, NxS, wurde ein Ringversuch durchgeführt. Dabei wurde sowohl der angestrebte Überlappungsbereich mit EN 12543 Teil 5 (Messung der effektiven Brennfleckgröße von Mini- und Mikrofokus-Röntgenröhren) und ASTM E 2903 (Standard Test Method for Measurement of the Effective Focal Spot Size of Mini and Micro Focus X-ray Tubes) für Brennflecke >5 μm als auch Brennflecke <5 μm untersucht. Im Mittelpunkt standen dabei Stabilität und Wiederholbarkeit der entwickelten Methoden zur Bestimmung der Brennfleckgröße. In diesem Beitrag werden die Ergebnisse des durchgeführten Ringversuches vorgestellt und diskutiert, um Schlussfolgerungen und Empfehlungen für die Vorbereitung eines erweiterten Ringversuchs mit Partnern und Stakeholdern abzuleiten.
T2 - DGZfP-Jahrestagung
CY - Kassel, Germany
DA - 23.05.2022
KW - Brennfleckmessung
KW - Computer-Tomografie
KW - EMPIR
KW - Normung
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561037
SP - 1
EP - 2
AN - OPUS4-56103
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Macková, A.
A1 - Malinský, P.
A1 - Jagerová, A.
A1 - Mikšová, A.
A1 - Lalik, O.
A1 - Nekvindová, P.
A1 - Mistrík, J.
A1 - Marvan, P.
A1 - Sofer, Z.
A1 - Holý, V.
A1 - Schütter, Jan David
A1 - Kentsch, U.
A1 - Azarov, A.
A1 - Galeckas, A.
T1 - Energetic Au ion beam implantation of ZnO nanopillars for optical response modulation
N2 - Nanopillars of ZnO were implanted with Au-400 keV ions at various ion fluences from 1 × 1015 cm−2 to 1 × 1016 cm−2 and subsequently annealed at 750 °C for 15 min in order to reduce the implantation damage and to support Au nanoparticle (NP) aggregation. It was found that implantation-induced effects and thermal effects influence the Au NP coalescence as well as the quality of the ZnO nanopillars. Rutherford Back-Scattering spectrometry (RBS) showed the broader Au-depth profiles than it was theoretically predicted, but the Au-concentration maximum agrees well with prediction taking into account the effective ZnO layer density. The implantation at the higher fluences induced the morphology modification of the nanopillar layer evidenced by RBS and scanning electron microscopy (SEM). An indirect evidence of this effect was given by optical ellipsometry due to gradual refractive index changes in the ZnO nanopillars with the increased Au-ion fluence. Optical characterization of the Au-implanted and annealed nanopillars performed by means of photoluminescence (PL) and diffuse-reflectance spectroscopy (DRS) evidenced the surface plasmon resonance (SPR) activity of the embedded Au NPs. The SPR-enhanced scattering and PL emission observed in the spectral range 500–650 nm are ascribed to Au NPs or more complex Au-clusters. In addition, the ellipsometry measurements of extinction coefficient are found to corroborate well results from DRS, both indicating increase of SPR effect with the increase of Au-ion fluence and after the post-annealing.
KW - ZnO nanopillars
KW - Ion beam implantation
PY - 2022
DO - https://doi.org/10.1088/1361-6463/ac5486
VL - 55
IS - 21
SP - 1
EP - 14
PB - IOP Publishing
AN - OPUS4-54394
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Engineered Nanomaterials- Novel Approaches for Risk Assessment and Safe-by-Design
N2 - The overall interest in nanotoxicity, triggered by the increasing use of nanomaterials in the material and life sciences, and the synthesis of an ever increasing number of new functional nanoparticles calls not only for standardized test procedures1,2 and for efficient approaches to screen the potential genotoxicity of these materials, but also for standardized and validated methods for surface analysis.
4,5 The analysis and quantification of surface chemistry is hence in the focus of an increasing number of standardization organizations and interlaboratory comparisons with different analytical methods are being done.5 For the monitoring of nanomaterial synthesis and the fast assessment of the number of functional groups such as carboxyl and amino functionalities, which are very commonly used functionalities in the life sciences, simple and validated methods are needed that can be performed with common laboratory instrumentation. 5,6 Here we provide a brief overview of the ongoing research in division Biophotonics employing quantitative NMR (qNMR), conductometry, and colorimetric and fluorometric optical assays for the determination of the total and the accessible number of carboxyl and amino groups on differently sized polymer and silica nano- and microparticles.5-7
T2 - Workshop NanoRiskSD project
CY - Berlin, Germany
DA - 09.06.2022
KW - Nanoparticle
KW - Surface analysis
KW - Standardization
KW - Quality assurance
KW - Validation
KW - qNMR
KW - Silica
KW - Polymer
KW - Fluorescence
KW - Assay
KW - Conductometry
KW - Method comparison
KW - Analytical sciences
PY - 2022
AN - OPUS4-54999
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sänger, Johanna Christiane
A1 - Pauw, Brian Richard
A1 - Riechers, Birte
A1 - Zocca, Andrea
A1 - Rosalie, Julian
A1 - Maaß, Robert
A1 - Sturm, Heinz
A1 - Günster, Jens
T1 - Entering a new dimension in powder processing for advanced ceramics shaping
N2 - Filigree structures can be manufactured via two-photon-polymerization (2PP) operating in the regime of non-linear light absorption. For the first time it is possible to apply this technique to the powder processing of ceramic structures with a feature size in the range of the critical defect size responsible for brittle fracture and, thus, affecting fracture toughness of high-performance ceramics. In this way, tailoring of advanced properties can be achieved already in the shaping process. Traditionally, 2PP relies on transparent polymerizable resins, which is diametrically opposed to the usually completely opaque ceramic resins and slurries. Here we present a transparent and photocurable suspension of nanoparticles (resin) with very high mass fractions of yttria-stabilized zirconia particles (YSZ). Due to the extremely well dispersed nanoparticles, scattering of light can be effectively suppressed at the process-relevant wavelength of 800 nm. Sintered ceramic structures with a resolution of down to 500 nm were obtained. Even at reduced densities of 1 to 4 g/cm³, the resulting compressive strength with 4,5 GPa is equivalent or even exceeding bulk monolithic yttria stabilized zirconia. A ceramic metamaterial is born, where the mechanical properties of yttria stabilized zirconia are altered by changing geometrical parameters and gives access to a new class of ceramic materials.
KW - Two-photon-polymerization
KW - Ceramics
KW - Powder processing
KW - Transparency
KW - Meta material
KW - Yttria stabilized zirconia
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564598
DO - https://doi.org/10.1002/adma.202208653
SN - 1521-4095
SP - 1
EP - 8
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-56459
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - RPRT
A1 - Zencker, Uwe
A1 - Simbruner, Kai
A1 - Völzke, Holger
T1 - Entwicklung eines bruchmechanischen Berechnungsansatzes zur Beschreibung des Festigkeitsverhaltens von Brennstabhüllrohren bei längerfristiger Zwischenlagerung (BRUZL)
N2 - Es werden Methoden zur sicherheitstechnischen Bewertung des mechanischen Verhaltens von Brennstabhüllrohren entwickelt, um sprödes Versagen in Belastungsszenarien nach längerfristiger trockener Zwischenlagerung zu verhindern. Unbestrahlte Brennstabhüllrohrsegmente aus der Zirkoniumlegierung ZIRLO® wurden hydriert und thermomechanischen Behandlungen unterzogen, um Hüllrohrmaterial durch Ausscheidung radialer Hydride zu verspröden. Die Proben mit radialen Hydriden wurden im Ring Compression Test (RCT) bei Raumtemperatur untersucht. Bereits bei kleinen Probenverformungen wurden abrupte Kraftabfälle mit instabiler Rissausbreitung durch das Netzwerk radialer Hydride beobachtet. Die Risslängen erreichten in einigen Fällen bis zu 90 % der Wanddicke. Der mikromechanische Versagensmechanismus ist Quasi-Spaltbruch in den Hydriden und Porenbildung, -wachstum und -vereinigung in der Zirkoniummatrix an den duktilen Brücken zwischen benachbarten Hydriden. Es wurde ein Finite-Elemente-Modell des Ring Compression Tests erstellt, um das Versagensverhalten zirkoniumbasierter Legierungen mit radialen Hydriden im RCT zu analysieren. Die Fließkurve für das elastisch-plastische Materialmodell des Matrixmaterials wurde durch eine inverse Finite-Elemente-Analyse ermittelt. Kohäsivzonenmodelle wurden benutzt, um die plötzlichen Kraftabfälle zu reproduzieren. Es wurde ein mikromechanisches Modell mit statistisch generierten Matrix-Hydrid-Verteilungen entwickelt, das zwischen sprödem Versagen entlang der Hydride und duktilem Versagen der Zirkoniummatrix in der Kohäsivzone unterscheidet. Für das jeweilige Materialverhalten wird ein lokales zweiparametriges Versagenskriterium auf Grundlage der Kohäsionsfestigkeit und der Separationsenergie bei einer festgelegten Form des Kohäsivgesetzes vorgeschlagen. Geeignete Kohäsivparameter lassen sich mit einer inversen Finite-Elemente-Analyse des Versagensverhaltens von hydrierten Proben im Ring Compression Test bestimmen. In den Simulationen lag der Schwerpunkt auf dem ersten Kraftabfall. Die Berechnungsergebnisse stimmen gut mit den RCT-Ergebnissen überein. Es konnte gezeigt werden, dass die Rissinitiierung und -ausbreitung stark von der speziellen Anordnung der radialen Hydride und Matrixbrücken in der Bruchzone abhängt. Die numerische Modellbildung wurde an Versuchen mit bestrahlten Proben aus der Zirkoniumlegierung M5® validiert.
KW - Zwischenlagerung
KW - Brennstabhüllrohr
KW - Versagensmechanismus
KW - Kohäsivzonenmodell
KW - Ring Compression Test
PY - 2022
SP - 1
EP - 106
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-56853
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CHAP
A1 - Szymoniak, Paulina
A1 - Schönhals, Andreas
ED - Schönhals, Andreas
ED - Szymoniak, Paulina
T1 - Epoxy-Based Nanocomposites—What Can Be Learned from Dielectric and Calorimetric Investigations?
N2 - Epoxy-based nanocomposites are promisingmaterials for industrial applications (i.e., aerospace, marine, and automotive industries) due to their extraordinary mechanical and thermal properties. Regardless of the broad field of applications, there is still a considerable need to identify their structure–property relationships. Here, a detailed dielectric and calorimetric (DSC and fast scanning calorimetry) study on different epoxy-based nanocomposites was performed. Bisphenol A diglycidyl ether (DGEBA) cured with diethylenetriamine (DETA) was employed as the polymeric matrix, which was reinforced with three diverse nanofillers that exhibit different interaction strengths with the epoxy matrix (halloysite nanotubes, surface modified halloysite nanotubes, and taurine-modified layered double hydroxide). The structure, molecular mobility, and vitrification behavior are discussed in detail, focusing on the intrinsic structural and dynamic heterogeneity, as well as interfacial properties.
KW - Nanocomposites
KW - Epoxi nanocomposites
KW - Dynamics
KW - Interphase
KW - Ridis amorphous fraction
KW - Dielectric spectroscopy
KW - Flash DSC
KW - Temparatur modulated Flash DSC
KW - Temperature modulated DSC
PY - 2022
DO - https://doi.org/10.1007/978-3-030-89723-9_11
SP - 335
EP - 367
PB - Springer
CY - Cham, Switzerland
AN - OPUS4-54566
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gornushkin, Igor B.
A1 - Veiko, V. P.
A1 - Karlagina, Y. Y.
A1 - Samokhvalov, A. A.
A1 - Polyakov, D. S.
T1 - Equilibrium model of titanium laser induced plasma in air with reverse deposition of titanium oxides
N2 - A chemical-hydrodynamic model of laser induced plasma is developed to study a process of deposition of titanium oxides from titanium laser induced plasma to the titanium target surface. The model is relevant to texturing and coating of titanium bone implants that is done by scanning the ablation laser across implant surfaces. Such the procedure improves the biocompatibility and durability of the implants. The model considers plasma chemical reactions, formation of condensed species inside the plasma plume, and deposition and accumulation of these species on the ablation surface. A chemical part of the model is based on minimization of Gibbs free energy of the chemical system; it is used to calculate the chemical composition of the plasma. A hydrodynamic part uses the 2D fluid-dynamic equations that model a 3D axisymmetric plasma plume and assumes the mass and energy exchange between the plasma and the surface. The initial parameters for the model are inferred from experiment.
The model shows that condensed titanium oxides, mostly TiO2, form in a peripheral plasma zone and gradually adhere to the surface during the plasma plume evolution. The model predicts the major component and thickness of the deposit and can be applied for the optimization of experiments aimed at surface modification.
KW - Fluid dynamic model
KW - Plasma chemistry
KW - Laser ablation
KW - Laser induced plasma deposition
KW - Surface coating
KW - Titanium dioxide
PY - 2022
DO - https://doi.org/10.1016/j.sab.2022.106449
SN - 0038-6987
SN - 0584-8547
VL - 193
SP - 1
EP - 7
PB - Elsevier
CY - Amsterdam
AN - OPUS4-54866
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Olscher, C.
A1 - Jandric, A.
A1 - Zafiu, C.
A1 - Part, Florian
T1 - Evaluation of marker materials and spectroscopic methods for tracer-based sorting of plastic wastes
N2 - Plastics are a ubiquitous material with good mechanical, chemical and thermal properties, and are used in all industrial sectors. Large quantities, widespread use, and insufficient management of plastic wastes lead to low recycling rates. The key challenge in recycling plastic waste is achieving a higher degree of homogeneity between the different polymer material streams. Modern waste sorting plants use automated sensor-based sorting systems capable to sort out commodity plastics, while many engineering plastics, such as polyoxymethylene (POM), will end up in mixed waste streams and are therefore not recycled. A novel approach to increasing recycling rates is tracer-based sorting (TBS), which uses a traceable plastic additive or marker that enables or enhances polymer type identification based on the tracer’s unique fingerprint (e.g., fluorescence). With future TBS applications in mind, we have summarized the literature and assessed TBS techniques and spectroscopic detection methods. Furthermore, a comprehensive list of potential tracer substances suitable for thermoplastics was derived from the literature. We also derived a set of criteria to select the most promising tracer candidates (3 out of 80) based on their material properties, toxicity profiles, and detectability that could be applied to enable the circularity of, for example, POM or other thermoplastics.
KW - Circular economy
KW - Post-consumer plastic waste
KW - Plastic waste recycling
KW - Tracer-based sorting
KW - Sensor-based sorting
KW - Spectroscopy
KW - Fluorescent markers
KW - Thermoplastics
KW - Polyoxymethylene
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555624
DO - https://doi.org/10.3390/polym14153074
SN - 2073-4360
VL - 14
SP - 1
EP - 20
PB - MDPI
CY - Basel
AN - OPUS4-55562
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Nietzke, Jonathan
A1 - Rhode, Michael
A1 - Mente, Tobias
A1 - Kannengießer, Thomas
T1 - Experimental and numerical characterization of hydrogen diffusion in thick-walled submerged arc welded joint of S420G2+M offshore steel grade
N2 - Offshore wind turbines are an important goal in national energy strategies worldwide. Foundation structures are manufactured from submerged arc welded (SAW) plates with thicknesses up to 200 mm. In that connection, high-strength steels like the S420G2+M are more and more applied offering the possibility for increased stability and load-bearing capacity of the foundations. These offshore steel grades can show a susceptibility for delayed hydrogen assisted cold cracking of the weld joints. For that purpose, a minimum waiting time (MWT) of up to 48 h (dependent on applied standards) is recommended before non-destructive testing is allowed and conducted. But this concept is based on older steel grades that have been used for three or more decades. Nowadays, the metallurgical improvements (clean steels, proper rolling, and heat treatment) of base materials and well as welding consumables must be anticipated. Hence, the MWT concept should be critically discussed as it is assumed to be very conservative. For that reason, the focus of this study was to investigate the diffusion behavior in S420G2+M steel and its multi-layer SAW joint. Electrochemical permeation experiments were carried at room temperature. Boundary conditions were anticipated in terms of using different sample thicknesses. From the experimental data, hydrogen diffusion coefficients and absorbed diffusible hydrogen concentrations had been calculated. It was shown that hydrogen diffusion in the base material is increased compared to the weld metal. In addition, the sample thickness had a significant on the calculated diffusion coefficients. The minimum and maximum diffusion coefficients had been used for numerical modelling of the hydrogen diffusion in the welding joint. It became clear that a MWT must be always regarded together with a critical initial diffusible hydrogen concentration for the evaluation of a possible delayed cracking as diffusion times were mostly > 48 h due to the thick plates.
T2 - 4th International Conference on Metals and Hydrogen - Steely & Hydrogen 2022
CY - Ghent, Belgium
DA - 11.10.2022
KW - Hydrogen
KW - Submerged arc welding
KW - Diffusion
KW - Minimum waiting time
KW - Electrochemical permeation
PY - 2022
SP - 1
EP - 11
CY - Ghent, Belgium
AN - OPUS4-56075
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fürst, Richard
A1 - Hejtmanek, P.
A1 - Vlach, T.
A1 - Repka, J.
A1 - Mozer, V.
A1 - Hajek, P.
T1 - Experimental Evaluation of Carbon Reinforced TRC with Cement Suspension Matrix at Elevated Temperature
N2 - Textile-reinforced concrete (TRC) is a new composite material comprising high-performance concrete and textile reinforcement from textile yarns with a matrix, usually consisting of epoxy resins (ER). The most significant advantage of ER is the homogenization of all filaments in the yarn and full utilization of its tensile potential. Nevertheless, ER matrix is a critical part of TRC design from the perspective of the fire resistance due to its relatively low resistance at temperatures of approximately 120 C. This work expands the previously performed mechanical tests at normal temperatures with cement suspension (CS) as a non-combustible material for the yarn matrix. Here, the mechanical properties of CS matrix at elevated temperatures were verified. It was found that the addition of polypropylene fibers into HPC negatively affected the mechanical results of CS matrix specimens. Simultaneously, thermal insulation effect of the covering layers with different thicknesses did not significantly influence the residual bending strength of specimens with CS matrix and achieved similar results as reference specimens. Furthermore, all specimens with ER matrix progressively collapsed. Finally, CS as a textile reinforcement of yarn matrix appears to be a suitable solution for increasing the temperature resistance of TRC structures and for substituting synthetic resins.
KW - Cement matrix
KW - Cement suspension
KW - Carbon fibers
KW - Textile reinforced concrete
KW - High-performance concrete
KW - Elevated temperature
KW - Fire safety
KW - Fire resistance
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550766
DO - https://doi.org/10.3390/polym14112174
SN - 2073-4360
VL - 14
IS - 11
SP - 1
EP - 16
PB - MDPI
CY - Basel, Switzerland
AN - OPUS4-55076
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Prajapati, Harshit Kumar
T1 - Experimental evolution of Deformed Wing Virus in developing honeybees (Apis mellifera)
N2 - The emergence of several infectious diseases in the last few decades has resulted in elevated honeybee (Apis mellifera) colony losses. Especially, (+) single-stranded RNA viruses (like Deformed Wing Virus) have become prominent due to a novel vector from Asia, the ectoparasitic mite – Varroa destructor. The evolution of DWV virulence is thought to have shifted dramatically since the arrival of V. destructor. According to the virulence trade-off theory, viruses found in vector-invaded hosts should evolve a certain level of virulence that optimizes transmission and subsequent spread. In this study, we aim to test this prediction by passaging DWV in white-eyed pupae by microinjection (10 generations), to emulate the vectoring function of V. destructor. Isolated viruses will be quantified, genotyped, and subjected to 3 transmission selection regimes: (i) Early: at 8 days, (ii) Optimal: at 11 days, and (iii) Late: at 14 days of injection. Viral genomes from all passages will be analyzed by combined data from high-throughput (Illumina NextSeq) and long-read (Oxford Nanopore) sequencing. Viral population dynamics will be reconstructed, linking of mutations to inter-host transmission and viral load, and site-/gene-specific tests of natural selection will be conducted
T2 - Ecological Immunology Conference 2022
CY - Heidesee, Germany
DA - 07.09.2022
KW - Evolution
KW - Varroa
KW - Honeybees
PY - 2022
AN - OPUS4-61714
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Villajos Collado, José Antonio
T1 - Experimental volumetric hydrogen uptake determination at 77 K of commercially available metal-organic framework materials
N2 - Storage is still limiting the implementation of hydrogen as an energy carrier to integrate the intermittent operation of renewable energy sources. Among different solutions to the currently used compressed or liquified hydrogen systems, physical adsorption at cryogenic temperature in porous materials is an attractive alternative due to its fast and reversible operation and the resulting reduction in storage pressure. The feasibility of cryoadsorption for hydrogen storage depends mainly on the performance of the used materials for the specific application, where metal-organic frameworks or MOFs are remarkable candidates. In this work, gravimetric and volumetric hydrogen uptakes at 77 K and up to 100 bar of commercially available MOFs were measured since these materials are made from relatively cheap and accessible building blocks. These materials also show relatively high porous properties and are currently near to large-scale production. The measuring device was calibrated at different room temperatures to calculate an average correction factor and standard deviation so that the correction deviation is included in the measurement error for better comparability with different measurements. The influence of measurement conditions was also studied, concluding that the available adsorbing area of material and the occupied volume of the sample are the most critical factors for a reproducible measurement, apart from the samples’ preparation before measurement. Finally, the actual volumetric storage density of the used powders was calculated by directly measuring their volume in the analysis cell, comparing that value with the maximum volumetric uptake considering the measured density of crystals. From this selection of commercial MOFs, the materials HKUST-1, PCN-250(Fe), MOF-177, and MOF-5 show true potential to fulfill a volumetric requirement of 40 g·L−1 on a material basis for hydrogen storage systems without further packing of the powders.
KW - Hydrogen adsorption
KW - Commercial metal-organic frameworks
KW - Hydrogen uptake reproducibility
KW - Volumetric uptake
KW - Packing density
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542215
DO - https://doi.org/10.3390/c8010005
SN - 2311-5629
VL - 8
IS - 1
SP - 1
EP - 14
PB - MDPI
CY - Basel
AN - OPUS4-54221
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - THES
A1 - Laquai, René
T1 - Extending synchrotron X-ray refraction imaging techniques to the quantitative analysis of metallic materials
N2 - In this work, two X-ray refraction based imaging methods, namely, synchrotron X-ray refraction radiography (SXRR) and synchrotron X-ray refraction computed tomography (SXRCT), are applied to analyze quantitatively cracks and porosity in metallic materials.
SXRR and SXRCT make use of the refraction of X-rays at inner surfaces of the material, e.g., the surfaces of cracks and pores, for image contrast. Both methods are, therefore, sensitive to smaller defects than their absorption based counterparts X-ray radiography and computed tomography. They can detect defects of nanometric size.
So far the methods have been applied to the analysis of ceramic materials and fiber reinforced plastics. The analysis of metallic materials requires higher photon energies to achieve sufficient X-ray transmission due to their higher density. This causes smaller refraction angles and, thus, lower image contrast because the refraction index depends on the photon energy. Here, for the first time, a conclusive study is presented exploring the possibility to apply SXRR and SXRCT to metallic materials. It is shown that both methods can be optimized to overcome the reduced contrast due to smaller refraction angles. Hence, the only remaining limitation is the achievable X-ray Transmission which is common to all X-ray imaging methods. Further, a model for the quantitative analysis of the inner surfaces is presented and verified.
For this purpose four case studies are conducted each posing a specific challenge to the imaging task. Case study A investigates cracks in a coupon taken from an aluminum weld seam. This case study primarily serves to verify the model for quantitative analysis and prove the sensitivity to sub-resolution features. In case study B, the
damage evolution in an aluminum-based particle reinforced metal-matrix composite is analyzed. Here, the accuracy and repeatability of subsequent SXRR measurements is investigated showing that measurement errors of less than 3% can be achieved. Further, case study B marks the fist application of SXRR in combination with in-situ tensile loading. Case study C is out of the highly topical field of additive manufacturing. Here, porosity in additively manufactured Ti-Al6-V4 is analyzed with a special interest in the pore morphology. A classification scheme based on SXRR measurements is devised which allows to distinguish binding defects from keyhole pores even if the defects cannot be spatially resolved. In case study D, SXRCT is applied to the analysis of hydrogen assisted cracking in steel. Due to the high X-ray attenuation of steel a comparatively high photonenergy of 50 keV is required here. This causes increased noise and lower contrast in the data compared to the other case studies. However, despite the lower data quality a quantitative analysis of the occurance of cracks in dependence of hydrogen content and applied mechanical load is possible.
N2 - In der vorliegenden Arbeit werden die zwei, auf Refraktion basierende, Röntgenbildgebungsverfahren Synchrotron Röntgen-Refraktions Radiographie (engl.: SXRR) und Synchrotron Röntgen-Refraktions Computertomographie (engl.: SXRCT) für die quantitative Analyse von Rissen und Porosität in metallischenWerkstoffen angewandt. SXRR und SXRCT nutzen die Refraktion von Röntgenstrahlen an inneren Oberflächen des Materials, z.B. die Oberflächen von Rissen und Poren, zur Bildgebung. Beide Methoden sind daher empfindlich gegenüber kleineren Defekten als ihre auf Röntgenabsorption basierenden Gegenstücke, Röntgenradiographie und Röntgen-Computertomographie.
Sie sind in der Lage Defekte von nanometrischer Größe zu detektieren. Bislang wurden die Methoden für die Analyse von keramischen Werkstoffen und faserverstärkten Kunststoffen eingesetzt. Die Analyse von metallischenWerkstoffen benötigt höhere Photonenenergien benötigt werden um eine ausreichende Transmission zu erreichen.
Dies hat kleinere Refraktionswinkel, und damit geringeren Bildkontrast, zur Folge, da der Brechungsindex von der Photonenenergie abhängt. Hier wird erstmals eine umfassende Studie vorgelegt, welche die Möglichkeiten zur Untersuchung metallischer Werkstoffe mittels SXRR und SXRCT untersucht. Es wird gezeigt, dass der geringere Kontrast, verursacht durch die kleineren Refraktionswinkel, überwunden werden kann. Somit ist die einzig verbleibende Beschränkung die erreichbare Transmission, die alle Röntgenbildgebungsverfahren gemeinsam haben. Darüber hinaus wird ein Modell für die quantitative Auswertung der inneren Oberflächen präsentiert und verifiziert.
Zu diesem Zweck werden vier Fallstudien durchgeführt, wobei jede eine spezifische Herausforderung darstellt. In Fallstudie A werden Risse in einer Probe aus einer Aluminiumschweißnaht untersucht. Diese Fallstudie dient hauptsächlich dazu das Modell für die quantitative Analyse zu verifizieren und die Empfindlichkeit gegenüber Strukturen unterhalb des Auflösungsvermögens zu beweisen. In Fallstudie B wird die Entwicklung der Schädigung in einem aluminiumbasierten partikelverstärktem Metall-Matrix Komposit untersucht. Dabei wird die Genauigkeit und Wiederholbarkeit der SXRR Messungen analysiert und es wird gezeigt das Messfehler kleiner 3% erreicht werden können. Darüber hinaus wird in Fallstudie B erstmals SXRR in Kombination mit in-situ Zugbelastung eingesetzt. Fallstudie C ist aus dem hochaktuellen Bereich der additive Fertigung. Hier wird Porosität in additiv gefertigtem Ti-Al6-V4 analysiert mit besonderem Augenmerk auf der Morphologie der Poren. Es wurde ein Verfahren zur Klassifizierung, basierend auf SXRR Messungen, erfunden, welches Bindefehler und Poren voneinander unterscheiden kann auch wenn die Defekte nicht räumlich aufgelöst werden können. In Fallstudie D wird SXRCT zur Analyse von wasserstoffunterstützter Rissbildung in Stahl angewandt. Wegen der hohen Röntgenschwächung des Stahls muss hier mit 50 keV eine vergleichsweise hohe Photonenenergie genutzt werden.
Dadurch zeigen die Daten ein erhöhtes Rauschen und geringeren Kontrast verglichen mit den anderen Fallstudien. Allerdings ist es, trotz der geringeren Datenqualität, möglich das Auftreten von Rissen in Abhängigkeit der Wasserstoffkonzentration und mechanischen Belastung zu untersuchen.
KW - Synchrotron X-ray refraction computed tomography
KW - Lean duplex steel X2CrMnNiN21-5-1
KW - hydrogen embrittlement
KW - Metal-matrix composite
KW - Al6061
KW - Ti-Al6-V4
KW - In-situ tensile test
PY - 2022
SP - 1
EP - 71
AN - OPUS4-54385
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hodoroaba, Vasile-Dan
T1 - External Liaison Report ISO/TC 202 'Microbeam Analysis' to ISO/TC 229 'Nanotechnologies'
N2 - The liaison report from the ISO Technical Committee ISO/TC 202 'Microbeam Analysis' for the November 2022 ISO/TC 229 Nanotechnologies Plenary Meeting Nanotechnologies Liaison Coordination Group (NLCG) is provided. Essential Information such as newly published standards and projects in develeopment relevant for ISO/TC 229 resulted from the progress within the last year and additional comments on behalf of ISO/TC 202 are included in the report.
KW - ISO/TC 202
KW - ISO/TC 229
KW - VAMAS
KW - Nanotechnologies
KW - Microbeam Analysis
KW - Standardisation
PY - 2022
SP - 1
EP - 4
CY - ISO, Geneva, CH
AN - OPUS4-56734
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - RPRT
A1 - Thieme-Hack, M.
A1 - Berghaus, U.
A1 - Brümmer, F.
A1 - Elsner, U.
A1 - Färber, C.
A1 - Frank, D.
A1 - Illgas, M.
A1 - Kalbe, Ute
A1 - Kathage, J.
A1 - Leers, A.
A1 - Müller, B.
A1 - Röger-Göpfert, C.
A1 - Russland, H.-J.
A1 - Schnabel, B.
A1 - Schneider, O.
A1 - Schockmann, D.
A1 - Schomakers, H.
A1 - Schwalbe, D.
A1 - Stegemann, D.
A1 - van den Berg, T.
A1 - Kramps, S.
T1 - Fachbericht Kunststoffsportböden - Nachhaltige Kunststoffbelagsauswahl für Sportfreianlagen
N2 - Kunststoff- und Kunststoffrasenflächen kommt bei intensiv genutzten Flächen als Allwetterbeläge eine große Bedeutung zu. Sie leisten einen wichtigen Beitrag zur Absicherung eines ganzjähriger Sportangebote.
Gerade Kunststoffrasen ist aber in den letzten Jahren häufig in die Kritik geraten, insbesondere durch gefährliche Inhaltsstoffe und andere negative Einflüsse auf die Umwelt. Dies hat bei Bauherren zu einer Verunsicherung geführt und Fragen aufgeworfen, die erst teilweise beantwortet sind. Die Diskussionen rund um diesen Allwetterbelag haben bereits dazu geführt, dass von Seiten der Industrie viel verändert wurde und neue innovative Lösungen gefunden werden.
Der Fachbericht stellt eine Handreichung für Fachleute und interessierte Laien dar, um mehr Klarheit besonders hinsichtlich der Umweltanforderungen zu erzielen.
KW - Kunststoffsportbeläge
KW - Kunstrasen
KW - Umweltverträglichkeit
KW - Schadstofftransfer
KW - Mikroplastik
PY - 2022
UR - https://shop.fll.de/de/fachbericht-kunststoffsportboeden-broschuere.html
SP - 1
EP - 70
PB - Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau (FLL)
CY - Bonn
AN - OPUS4-54390
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kornev, R.
A1 - Gornushkin, Igor B.
A1 - Nazarov, V.
A1 - Shkrunin, V.
A1 - Ermakov, A.
T1 - Features of hydrogen reduction of SiF4 in ICP plasma
N2 - Probe diagnostics is used to determine the electron temperature and electron number density in a low pressure inductively coupled plasma (ICP) ignited in the mixture of SiF4, Ar and H2. Emission spectra of mixtures with different stoichiometry of components are investigated and the electron density distribution function (EDDF) is estimated. The optimal conditions for high conversion of SiF4 into Si are found by studying the dependence of the yield of silicon upon the ratio of reagents. The maximum achieved yield of silicon is 85% under the optimal conditions. Based on the analysis of IR and MS spectra of exhaust gases, 5% of initial SiF4 converts into volatile fluorosilanes. A rate of production of Si is 0.9 g/h at the energy consumption 0.56 kWh /g.
KW - Plasma enhanced chemical vapor deposition
KW - PECVD
KW - Silicon tetrafluoride
KW - Emission spectroscopy
KW - Probe diagnostics
PY - 2022
DO - https://doi.org/10.1016/j.sab.2022.106502
SN - 0584-8547
VL - 195
SP - 106502
PB - Elsevier B.V.
AN - OPUS4-55316
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schneider, Rudolf
T1 - Field Analysis by Antibody-based Analytical Methods: The Importance of Advanced Materials
N2 - Analytical methods based on the selectivity of antibodies, often called immunoassays, are a back-bone of clinical laboratory diagnostics. To bring them to the field, i.e., to make immunoanalytical methods portable, hopefully even faster, more sensitive, and robust, advanced materials are re-quired. Materials can be novel labels, e.g., chemical or particle labels, such as fluorophores or na-noparticles. Carrier particles, such as magnetic or polymer beads, make it possible to adopt the as-says to meso- or microfluidic set-ups and encoding them opens the path to multiplex analysis. Spe-cialty electrodes can enable for higher sensitivity in electrochemical detection. Without research into better materials, efforts to bring analysis to the point-of-need will not bear fruit.
T2 - Kolloquium des Aveiro Institut of Materials (CICECO) der Universität Aveiro
CY - Aveiro, Portugal
DA - 20.09.2022
KW - Immunoassay
KW - Biosensor
KW - Antibody
PY - 2022
AN - OPUS4-56785
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Knigge, Xenia
T1 - First Experiences with the new HAXPES@BAM
N2 - This talk was part of the inauguration event for the new x-ray photoelectron spectrometer with the possibility to measure HAXPES (hard energy x-ray photoelectron spectroscopy). With HAXPES detailed chemical information can now be gained not only from the first outermost nanometres of the sample surface, but also from deeper regions. In this talk first results and experiences handling the spectrometer are shown.
T2 - Inauguration of the HAXPES@BAM - A new Hard-X-Ray Photoelectron Spectrometer
CY - Online meeting
DA - 25.01.2022
KW - HAXPES
KW - Nano@BAM
KW - Surface Analysis
KW - XPS
PY - 2022
UR - https://www.bam.de/Content/EN/Events/2022/2022-01-25-hapex.html
AN - OPUS4-54434
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 - Vigna, L.
A1 - Gottschalk, Martin
A1 - Cacocciola, N.
A1 - Verna, A.
A1 - Marasso, S. L.
A1 - Seeger, Stefan
A1 - Pirri, C.F.
A1 - Cocuzza, M.
T1 - Flexible and reusable parylene C mask technology for applications in cascade impactor air quality monitoring systems
N2 - The development of traceable new methodologies to quantify elemental air pollutants in particulate matter (PM) supports modernization of methods used in air quality monitoring networks in Europe. In the framework of the EURAMET EMPIR AEROMET II project, the combination of cascade impactor aerosol sampling and total reflection X-ray fluorescence elemental spectroscopy (TXRF) was investigated. This technique requires a traceable calibration based on reference samples. This paper describes a new, simple and effective method to produce such reference samples using flexible, reusable, and low-cost parylene C shadow masks, fabricated by photolithographic steps. These shadow masks can be used to produce reference samples that mimic the Dekati cascade impactor’s deposition patterns by applying as-prepared micro stencils to 30 mm acrylic substrates and evaporating a reference material (Ti) in arrangements of thin circular dots. The highly flexible direct patterning of acrylic discs with reference material, otherwise impossible with conventional photolithography, allows multiple reusing of the same micro stencils. The aspect ratios of the dots could be repeated with an error less than 4 %. A first set of standard reference samples for the 13 stages of the Dekati cascade impactor was produced and preliminary TXRF measurements of the deposited Ti masses were performed. The centricity of the deposition patterns turned out to be an important parameter for the quality of the TXRF results. The parylene mask technology for the production of reference samples turns out to be a promising new approach for the traceable calibration of TXRF spectrometers for the quantification of element concentrations in environmental aerosol samples but, due to its great versatility, it could be used for several other micropatterning applications on conventional and unconventional substrates.
KW - AEROMET II
KW - Aerosol
KW - Parylene C
KW - Reference samples
KW - Flexible shadow masks
KW - Cascade impactor
KW - Air quality monitoring
KW - Micropatterning
KW - Mask fabrication
KW - Elemental aerosol analysis
KW - TXRF
PY - 2022
DO - https://doi.org/10.1016/j.mne.2022.100108
SN - 2590-0072
VL - 14
SP - 1
EP - 19
PB - Elsevier B.V.
CY - Amsterdam
AN - OPUS4-54252
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Meng, M.
A1 - Zhang, T.
A1 - Wang, J.
A1 - Cheng, Z.
A1 - Yang, J.
A1 - Qiao, X.
A1 - Wen, J.
A1 - Resch-Genger, Ute
A1 - Ou, J.
T1 - Fluorescence temperature sensing of NaYF4:Yb3+/Tm3+@NaGdF4:Nd3+/Yb3+ nanoparticles at low and high temperatures
N2 - NaYF4:Yb3+/Tm3+@NaGdF4:Nd3+/Yb3+ upconversion nanoparticles (UCNPs) were prepared using a solvothermal method, and the effects of key factors such as the content of sensitiser Nd 3+ and Yb3+ on their luminescence properties were investigated. The nanoparticles are homogeneous in size and well dispersed. Under 808 nm excitation, it can produce strong upconversion fluorescence. At the same time, the nanoparticles have good temperature-sensing properties at the thermally coupled energy levels of 700 nm and 646 nm for Tm3+. Using its fluorescence intensity ratio (FIR), accurate temperature measurements can be performed, and it has been found that it exhibits different temperature sensing properties in low and high-temperature regions. The maximum relative sensitivity was found to be 0.88% K-1 and 1.89% K-1 for the lowtemperature region of 285 K-345 K and the high-temperature region of 345 K-495 K. The nanoparticles were applied to the internal temperature measurement of lithium batteries and the actual high-temperature environment, respectively, and were found to have good temperature measurementt performance.
KW - Fluorescence
KW - Sensor
KW - Temperature
KW - Ratiometric
KW - Lanthanide
KW - Quantum yield
KW - Integrating sphere spectroscopy
KW - Absolute fluorescence
KW - Quality assurance
KW - Nano
KW - Particle
KW - Application
KW - Upconversion nanoparticle
PY - 2022
DO - https://doi.org/10.1088/1361-6528/ac84e4
SN - 1361-6528
VL - 33
IS - 34
SP - 1
EP - 15
PB - IOP Publishing
CY - Bristol
AN - OPUS4-55454
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kimani, Martha Wamaitha
A1 - Kislenko, Evgeniia
A1 - Gawlitza, Kornelia
A1 - Rurack, Knut
T1 - Fluorescent molecularly imprinted polymer particles for glyphosate detection using phase transfer agents
N2 - In this work, molecular imprinting was combined with direct fluorescence detection of the pesticide Glyphosate (GPS). Firstly, the solubility of highly polar GPS in organic solvents was improved by using lipophilic tetrabutylammonium (TBA+) and tetrahexylammonium (THA+) counterions. Secondly, to achieve fluorescence detection, a fluorescent crosslinker containing urea-binding motifs was used as a probe for GPS-TBA and GPS-THA salts in chloroform, generating stable complexes through hydrogen bond formation. The GPS/fluorescent dye complexes were imprinted into 2–3 nm fluorescent molecularly imprinted polymer (MIP) shells on the surface of sub-micron silica particles using chloroform as porogen. Thus, the MIP binding behavior could be easily evaluated by fluorescence titrations in suspension to monitor the spectral changes upon addition of the GPS analytes. While MIPs prepared with GPS-TBA and GPS-THA both displayed satisfactory imprinting following titration with the corresponding analytes in chloroform, GPS-THA MIPs displayed better selectivity against competing molecules. Moreover, the THA+ counterion was found to be a more powerful phase transfer agent than TBA+ in a biphasic assay, enabling the direct fluorescence detection and quantification of GPS in water. A limit of detection of 1.45 μM and a linear range of 5–55 μM were obtained, which match well with WHO guidelines for the acceptable daily intake of GPS in water (5.32 μM).
KW - Glyphosate
KW - Molecular imprinting
KW - Core-shell particles
KW - Fluorescent sensors
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555281
DO - https://doi.org/10.1038/s41598-022-16825-9
SN - 2045-2322
VL - 12
IS - 1
SP - 1
EP - 15
PB - Macmillan Publishers Limited
CY - London
AN - OPUS4-55528
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Neumann, Patrick P.
A1 - Hirschberger, Paul
A1 - Bartholmai, Matthias
ED - Holl, H.
T1 - Flying ant robot for chemical trail detection and localization
N2 - This paper presents first advances in the area of aerial chemical trail following. For that purpose, we equipped a palm-size aerial robot, based on the Crazyflie 2.0 quadrocopter, with a small lightweight metal oxide gas sensor for measuring evaporated ethanol from chemical trails. To detect and localize a 5 cm wide chemical trail, a detection criterion was developed that uses only relative changes in the transient phase of the sensor response. The reduction in signal strength dependence improves the robustness of its application. We tested our setup in first crossing-trail experiments showing that our flying ant robot can correlate an odor hit with the chemical trail within 0.14 m. Principally, this could enable aerial chemical trail following in the future.
T2 - 37th Danubia - Adria Symposium on Advances in Experimental Mechanics
CY - Linz, Austria
DA - 21.09.2021
KW - Aerial robot
KW - Trail following
KW - Trail detection
KW - Localization
PY - 2022
DO - https://doi.org/10.1016/j.matpr.2022.02.594
SN - 2214-7853
VL - 62
SP - 2462
EP - 2465
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-54507
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bruna, F. G.
A1 - Prokop, M.
A1 - Bystron, T.
A1 - Loukrakpam, R.
A1 - Melke, J.
A1 - Lobo, C. M. S.
A1 - Fink, M.
A1 - Zhu, M.
A1 - Voloshina, E.
A1 - Kutter, M.
A1 - Hoffmann, H.
A1 - Yusenko, Kirill
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, B.
A1 - Bouzek, K.
A1 - Paulus, B.
A1 - Roth, C.
T1 - Following adsorbed intermediates on a platinum gas diffusion electrode in H3PO3‑containing electrolytes using in situ X‑ray absorption spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalyst with H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - Δμ XANES
KW - H3PO3
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - ACS
CY - Washington, DC
AN - OPUS4-55815
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gomes, Bruna F.
A1 - Prokop, Martin
A1 - Bystron, Tomas
A1 - Loukrakpam, Rameshwori
A1 - Melke, Julia
A1 - Lobo, Carlos M. S.
A1 - Fink, Michael
A1 - Zhu, Mengshu
A1 - Voloshina, Elena
A1 - Kutter, Maximilian
A1 - Hoffmann, Hendrik
A1 - Yusenko, Kirill V.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, Bettina
A1 - Bouzek, Karel
A1 - Paulus, Beate
A1 - Roth, Christina
T1 - Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using In Situ X-ray Absorption Spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalystwith H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate Proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - H3PO3,
KW - Δμ XANES
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - American Chemical Society (ACS)
AN - OPUS4-64733
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Martins, Ines
A1 - Al-Sabbagh, Dominik
A1 - Bentrup, U.
A1 - Marquardt, Julien
A1 - Schmid, Thomas
A1 - Scoppola, E.
A1 - Kraus, Werner
A1 - Stawski, Tomasz
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Yusenko, Kirill
A1 - Weidner, Steffen
A1 - Emmerling, Franziska
T1 - Formation Mechanism of a Nano-Ring of Bismuth Cations and Mono-Lacunary Keggin-Type Phosphomolybdate
N2 - A new hetero-bimetallic polyoxometalate (POM) nano-ring was synthesized in a one-pot procedure. The structure consists of tetrameric units containing four bismuth-substituted monolacunary Keggin anions including distorted [BiO8] cubes. The nano-ring is formed via self-assembly from metal precursors in aqueous acidic medium. The compound (NH4)16[(BiPMo11O39)4] ⋅ 22 H2O; (P4Bi4Mo44) was characterized by single-crystal X-ray diffraction, extended X-ray absorption fine structure spectroscopy (EXAFS), Raman spectroscopy, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF), and thermogravimetry/differential scanning calorimetry mass spectrometry (TG-DSC-MS). The formation of the nano-ring in solution was studied by time-resolved in situ small- and wide-angle X-ray scattering (SAXS/WAXS) and in situ EXAFS measurements at the Mo−K and the Bi−L3 edge indicating a two-step process consisting of condensation of Mo-anions and formation of Bi−Mo-units followed by a rapid self-assembly to yield the final tetrameric ring structure.
KW - Bismuth
KW - In situ EXAFS
KW - In situ SAXS/WAXS
KW - Lacunary Keggin ion
KW - Polyoxometalates
KW - Self-assembly
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546823
DO - https://doi.org/10.1002/chem.202200079
SN - 0947-6539
VL - 28
IS - 27
SP - 1
EP - 7
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54682
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
T1 - Forschungsprogramm 2022 - 2024
N2 - Der Koalitionsvertrag der Bundesregierung betont in seiner Präambel zur Zukunft Deutschlands in Bezug auf die notwendige Modernisierung, dass „dieser Fortschritt auch mit einem Sicherheitsversprechen einhergehen muss“. Die Bundesanstalt für Materialforschung und -prüfung (BAM) stellt mit ihrem Auftrag „Sicherheit in Technik und Chemie“ und ihrer über 150-jährigen Kompetenz sicher, dass ein nachhaltiger technischer Fortschritt von einem Sicherheitsversprechen für die Bürger*innen begleitet ist.
Durch ihre Interdisziplinarität, die thematische Breite, die langjährige Erfahrung und die unabhängige Rolle als Ressortforschungseinrichtung ist die BAM in einer herausragenden Lage, als zentraler Akteur die Entwicklung unterschiedlichster Technologien unter Berücksichtigung sicherheitstechnischer Aspekte voranzubringen, das Vertrauen der Gesellschaft in diese Technologien sicherzustellen und dadurch die Basis für erfolgreiche Innovationen zu schaffen.
Der Fokus ihrer Arbeit liegt auf den fünf Themenfeldern Energie, Infrastruktur, Umwelt, Material und Analytical Sciences. Wichtige Themen betreffen dabei sowohl die Energiewende (Wasserstoff, elektrische Energiespeicher, Windenergie) als auch Bereiche der Technologiesouveränität wie die additive Fertigung, zuverlässige Materialdaten, Zustandsüberwachung und Kreislaufwirtschaft.
Die Digitalisierung und den digitalen Wandel unterstützt die BAM in Bezug auf technologieübergreifende Rahmenbedingungen besonders in der Initiative Qualitätsinfrastruktur-Digital (QI-Digital), in der gemeinsam mit weiteren zentralen Akteuren der deutschen QI Lösungen für die Qualitätssicherung in einer digitalisierten Welt entwickelt werden.
Grundvoraussetzung für sichere Technologien und Innovationen ist eine leistungsfähige Forschung und Entwicklung ebenso wie Wissens- und Technologietransfer zur Umsetzung von Forschungsergebnissen in marktfähige Produkte und Dienstleistungen. Dafür bildet die Arbeit der BAM eine wichtige Basis.
Ihre Forschung ist mit der Wahrnehmung öffentlicher Aufgaben verbunden. Das Forschungsprogramm zeigt Perspektiven im Bereich ihres Aufgabenfeldes sowie ihrer damit verbundenen Forschungsaktivitäten transparent und politisch nutzbar auf und dient darüber hinaus der Koordinierung der Ressortforschung.
Das Forschungsprogramm der BAM wird alle zwei Jahre aktualisiert. Es gibt einen Überblick über die aktuellen und zukünftigen Forschungsthemen und die hierfür erforderlichen Rahmenbedingungen.
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572758
SP - 1
EP - 40
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-57275
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hülagü, Deniz
A1 - Tobias, Charlie
A1 - Gojani, Ardian B.
A1 - Rurack, Knut
A1 - Hodoroaba, Vasile-Dan
T1 - From 2D and Single Particle to 3D and Batch Analysis as a Routine Quality Check Procedure for the Morphological Characterization of Core-Shell Microparticles
N2 - CS particles show unique properties by merging individual characteristics of the core and the shell materials. An alteration particularly in their surface roughness affects the final performance of the particles in the targeted application. Quantitative evaluation of the roughness of CS microparticles is, however, a challenging task employing microscopic techniques being scarce and showing large differences in terms of methodology and results.
In our previous work, we have reported a systematic study with a reliable analysis tool, which evaluates profile roughness quantitatively, for individual core-shell microparticles using electron microscopy (EM) images of both types, Scanning Electron Microscopy (SEM) and transmission mode SEM (or TSEM). The SEM images contain two-dimensional (2D) information, therefore, provide profile roughness data only from the projection in the horizontal plane (in other words, from the “belly”) of a spherical particle. The present study offers a practical procedure to give access to more information by tilting the sample holder and hence allowing images of a single particle to be recorded at different orientations under the same view angle. From the analysis of these images, extended information on surface roughness of the particle can be extracted. Thus, instead of obtaining 2D information from a single SEM image, three-dimensional (3D) information is obtained from 2D projections recorded at different particle orientations.
T2 - Microscopy and Microanalysis 2022
CY - Oregon, Portland, USA
DA - 31.07.2022
KW - Core-shell particles
KW - Image processing
KW - Roughness
KW - Scanning electron microscopy
KW - Tilting
PY - 2022
DO - https://doi.org/10.1017/S1431927622002094
SN - 1431-9276
VL - 28
IS - S1
SP - 332
EP - 334
PB - Cambridge University Press
AN - OPUS4-55373
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Functional molecular chromophores and nanomaterials reporters, optical probes, and sensors
N2 - •Overview of expertise of division Biophotonics
•Functional molecular and nanoscale luminescent reporters, probes, and
sensors including design principles available from division Biophotonics
•Examples for pH and O2 responsive molecular probes and particle sensors
•Surface group quantification Analytical methods and cleavable probes
•Concepts & standards for the validation and traceability of optical measurements
T2 - FU-Seminar
CY - Berlin, Germany
DA - 09.12.2022
KW - Particle sensors
KW - Surface group quantification
KW - Nanoscale luminescent reporters
KW - Cleavable probes
PY - 2022
AN - OPUS4-56526
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Singh, Chandan
T1 - Functionalized Titanium Carbide Nanosheets based Biosensor for Detection of the SARS-CoV-2 Nucleocapsid Protein
N2 - MXenes are a new family of two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides discovered in 2011. Among many reported family members, titanium carbide is the most widely studied and explored due to the optimized synthesis conditions and promising characteristics like good mechanical strength, solution processability, and excellent conductivity. Here, we report the development of an electrochemical biosensor involving the amine-functionalized Few-Layered-Titanium Carbide Nanosheets and monoclonal antibodies against the SARS-CoV-2 nucleocapsid protein (anti-SARS-CoV-2 mAb) to design a point-of-care device for detection of the SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 NP) antigen.
T2 - SALSA's Make and Measure 2022
CY - Berlin, Germany
DA - 15.09.2022
KW - MXenes
KW - Titanium Carbide Nanosheets
KW - Biosensors
KW - Electrochemistry
PY - 2022
N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S.
AN - OPUS4-55856
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hülagü, Deniz
A1 - Tobias, Charlie
A1 - Climent Terol, Estela
A1 - Gojani, Ardian
A1 - Rurack, Knut
A1 - Hodoroaba, Vasile-Dan
T1 - Generalized Analysis Approach of the Profile Roughness by Electron Microscopy with the Example of Hierarchically Grown Polystyrene–Iron Oxide–Silica Core–Shell–Shell Particles
N2 - The roughness as a property of core–shell (CS) microparticles plays a key role in their functionality. Quantitative evaluation of the roughness of CS microparticles is, however, a challenging task with approaches using electron microscopy images being scarce and showing pronounced differences in terms of methodology and results. This work presents a generalized method for the reliable roughness determination of nonplanar specimens such as CS particles from electron microscopic images, the method being robust and reproducible with a high accuracy. It involves a self-written software package (Python) that analyzes the recorded images, extracts corresponding data, and calculates the roughness based on the deviation of the identified contour. Images of single particles are taken by a dual mode scanning electron microscopy (SEM) setup which permits imaging of the same field-of-view of the sample with high resolution and surface sensitive in SE InLens mode as well as in transmission mode (TSEM). Herein, a new type of polystyrene core–iron oxide shell–silica shell particles is developed to serve as a set of lower micrometer-sized study objects with different surface roughness; the analysis of their images by the semiautomatic workflow is demonstrating that the particles’ profile roughness can be quantitatively obtained.
KW - Core–shell particles
KW - Image analysis
KW - Nanoparticles
KW - Roughness
KW - SEM
KW - transmission mode
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542576
DO - https://doi.org/10.1002/adem.202101344
SP - 1
EP - 9
PB - Wiley-VCH
AN - OPUS4-54257
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Erdmann, Eileen
A1 - Nitsche, Sarah
A1 - Gorbushina, Anna
A1 - Schumacher, Julia
T1 - Genetic Engineering of the Rock Inhabitant Knufia petricola Provides Insight Into the Biology of Extremotolerant Black Fungi
N2 - Black microcolonial fungi (Ascomycetes from Arthonio-, Dothideo-, and Eurotiomycetes) are stress-tolerant and persistent dwellers of natural and anthropogenic extreme habitats. They exhibit slow yeast-like or meristematic growth, do not form specialized reproduction structures and accumulate the black pigment 1,8-dihydroxynaphthalene (DHN) melanin in the multilayered cell walls. To understand how black fungi live, survive, colonize mineral substrates, and interact with phototrophs genetic methods are needed to test these functions and interactions. We chose the rock inhabitant Knufia petricola of the Chaetothyriales as a model for developing methods for genetic manipulation. Here, we report on the expansion of the genetic toolkit by more efficient multiplex CRISPR/Cas9 using a plasmid-based system for expression of Cas9 and multiple sgRNAs and the implementation of the three resistance selection markers genR (geneticin/nptII), baR (glufosinate/bar), and suR (chlorimuron ethyl/sur). The targeted integration of expression constructs by replacement of essential genes for pigment synthesis allows for an additional color screening of the transformants. The black-pink screening due to the elimination of pks1 (melanin) was applied for promoter studies using GFP fluorescence as reporter. The black-white screening due to the concurrent elimination of pks1 and phs1 (carotenoids) allows to identify transformants that contain the two expression constructs for co-localization or bimolecular fluorescence complementation (BiFC) studies. The co-localization and interaction of the two K. petricola White Collar orthologs were demonstrated. Two intergenic regions (igr1, igr2) were identified in which expression constructs can be inserted without causing obvious phenotypes. Plasmids of the pNXR-XXX series and new compatible entry plasmids were used for fast and easy generation of expression constructs and are suitable for a broad implementation in other fungi. This variety of genetic tools is opening a completely new perspective for mechanistic and very detailed study of expression, functioning and regulation of the genes/proteins encoded by the genomes of black fungi.
KW - Microcolonial fungi
KW - DHN melanin
KW - Cloning vectors
KW - Genetics
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546192
DO - https://doi.org/10.3389/ffunb.2022.862429
SN - 2673-6128
VL - 3
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-54619
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schneider, Beate
A1 - Pfeiffer, F.
A1 - Dyall-Smith, M.
A1 - Kunte, Hans-Jörg
T1 - Genome Sequence of Cupriavidus campinensis Strain G5, a Member of a Bacterial Consortium Capable of Polyethylene Degradation
N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G5 was determined by PacBio sequencing. Using the TYGS for taxonomic classification, strain G5 was assigned to the species Cupriavidus campinensis.
KW - Polyethylene
KW - Cupriavidus campinensis
KW - Plastic degradation
KW - Genome sequence
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557897
DO - https://doi.org/10.1128/mra.00553-22
SP - 1
EP - 2
PB - ASM
AN - OPUS4-55789
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schneider, Beate
A1 - Pfeiffer, F.
A1 - Dyall-Smith, M.
A1 - Kunte, Hans-Jörg
T1 - Genome Sequence of Micromonospora aurantiaca Strain G9, a Member of a Bacterial Consortium Capable of Polyethylene Degradation
N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G9 was determined by PacBio sequencing. Using the TYGS server for taxonomic classification, strain G9 was assigned to the species Micromonospora aurantiaca.
KW - Polyethylene
KW - Micromonospora aurantiaca
KW - Degradation
KW - iChip
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547181
DO - https://doi.org/10.1128/mra.01148-21
SN - 2576-098X
VL - 11
IS - 5
SP - 1
EP - 2
PB - American Society for Microbiology
CY - Washington, DC
AN - OPUS4-54718
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schneider, Beate
A1 - Pfeiffer, F.
A1 - Dyall-Smith, M.
A1 - Kunte, Hans-Jörg
T1 - Genome Sequence of Pseudomonas veronii Strain G2, a Member of a Bacterial Consortium Capable of Polyethylene Degradation
N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G2 was determined by PacBio sequencing. Using the TYGS server for taxonomic classification, strain G2 was assigned to the species Pseudomonas veronii.
KW - Polyethylene
KW - Next generation sequencing
KW - Pseudomonas veronii
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548973
DO - https://doi.org/10.1128/mra.00365-22
SP - 1
EP - 2
PB - ASM
AN - OPUS4-54897
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Darvishi Kamachali, Reza
T1 - Grain Boundary Segregation Design using CALPHAD-integrated Phase-Field Modelling
N2 - A main source of current challenges in materials science and engineering is the ever-increasing complexity in materials chemistry and processing resulting in complex microstructures, making the assessment of process-microstructure-property-performance relations difficult, even unmanageable. Here the computational materials science is facing the same situation. In this talk, I share a viewpoint that the complexities in chemistry, processing and microstructures can be circumscribed by integrating existing knowledges of bulk thermodynamics and kinetics to the unknown thermodynamics and kinetics of microstructure elements. To this end, I discuss several successful examples on grain boundary segregation engineering how this scientific advance can be conducted. A roadmap is proposed, beginning to form on generalizing the concept of phase diagrams.
T2 - ICAMS Advance Discussions: Advanced models for microstructure evolution – process-microstructure-property relationships
CY - Bochum, Germany
DA - 26.10.2022
KW - Microstructure Design
KW - CALPHAD
KW - Phase-Field Simulations
KW - Machine Learning
KW - Phase Diagrams
PY - 2022
AN - OPUS4-56348
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fahmy, A.
A1 - Anis, B.
A1 - Szymoniak, Paulina
A1 - Altmann, Korinna
A1 - Schönhals, Andreas
T1 - Graphene Oxide/Polyvinyl Alcohol–Formaldehyde Composite Loaded by Pb Ions: Structure and Electrochemical Performance
N2 - An immobilization of graphene oxide (GO) into a matrix of polyvinyl formaldehyde (PVF) foam as an eco-friendly, low cost, superior, and easily recovered sorbent of Pb ions from an aqueous solution is described. The relationships between the structure and electrochemical properties of PVF/GO composite with implanted Pb ions are discussed for the first time. The number of alcohol groups decreased by 41% and 63% for PVF/GO and the PVF/GO/Pb composite, respectively, compared to pure PVF. This means that chemical bonds are formed between the Pb ions and the PVF/GO composite based on the OH groups. This bond formation causes an increase in the Tg values attributed to the formation of a strong surface complexation between adjacent layers of PVF/GO composite. The conductivity increases by about 2.8 orders of magnitude compared to the values of the PVF/GO/Pb composite compared to the PVF. This means the presence of Pb ions is the main factor for enhancing the conductivity where the conduction mechanism is changed from ionic for PVF to electronic conduction for PVF/GO and PVF/GO/Pb.
KW - Graphene oxide
KW - Polyvinyl formaldehyde
KW - Lead ions
KW - Conductivity
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549588
DO - https://doi.org/10.3390/polym14112303
SN - 2073-4360
VL - 14
IS - 11
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-54958
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Jungnickel, R.
A1 - Mirabella, Francesca
A1 - Stockmann, Jörg Manfred
A1 - Radnik, Jörg
A1 - Balasubramanian, K.
T1 - Graphene‑on‑gold surface plasmon resonance sensors resilient to high‑temperature annealing
N2 - Gold films coated with a graphene sheet are being widely used as sensors for the detection of label-free binding interactions using surface plasmon resonance (SPR). During the preparation of such sensors, it is often essential to subject the sensor chips to a high-temperature treatment in order to ensure a clean graphene surface. However, sensor chips used currently, which often use chromium as an adhesion promoter, cannot be subjected to temperatures above 250 °C, because under such conditions, chromium is found to reorganize and diffuse to the surface, where it is easily oxidized, impairing the quality of SPR spectra. Here we present an optimized preparation strategy involving a three-cycle tempering coupled with chromium (oxide) etching, which allows the graphene-coated SPR chips to be annealed up to 500 °C with little deterioration of the surface morphology. In addition, the treatment delivers a surface that shows a clear enhancement in spectral response together with a good refractive index sensitivity. We demonstrate the applicability of our sensors by studying the kinetics of avidin–biotin binding at different pH repeatedly on the same chip. The possibility to anneal can be exploited to recover the original surface after sensing trials, which allowed us to reuse the sensor for at least six cycles of biomolecule adsorption.
KW - Surface plasmon resonance
KW - Graphene
KW - Sensing
KW - Surface regeneration
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564585
DO - https://doi.org/10.1007/s00216-022-04450-4
SN - 1618-2642
SP - 1
EP - 7
PB - Springer
AN - OPUS4-56458
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Altmann, Korinna
T1 - Harmonisation efforts of the CUSP projects
N2 - The talk is about harmonisation approaches within CUSP. First the five H2020 projects for research on risk assessment regarding microplastics topic were presented. Secondly, harmonisation process were discussed.
T2 - VAMAS SC 47 Meeting
CY - Turin, Italy
DA - 19.10.2022
KW - Microplastics
KW - Harmonisation
KW - Nanoplastics
KW - H2020
KW - Risk assessment
PY - 2022
AN - OPUS4-56077
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zou, Q.
A1 - Marcelot, C.
A1 - Ratel-Ramond, N.
A1 - Yi, X.
A1 - Roblin, P.
A1 - Frenzel, Florian
A1 - Resch-Genger, Ute
A1 - Eftekhari, A.
A1 - Bouchet, A.
A1 - Coudret, C.
A1 - Verelst, M.
A1 - Chen, X.
A1 - Mauricot, R.
A1 - Roux, C.
T1 - Heterogeneous Oxysulfide@Fluoride Core/ Shell Nanocrystals for Upconversion-Based Nanothermometry
N2 - Lanthanide (Ln3+)-doped upconversion nanoparticles (UCNPs) often suffer from weak luminescence, especially when their sizes are ultrasmall (less than 10 nm). Enhancing the upconversion luminescence (UCL) efficiency of ultrasmall UCNPs has remained a challenge that must be undertaken if any practical applications are to be envisaged. Herein, we present a Ln3+-doped oxysulfide@fluoride core/shell heterostructure which shows efficient UCL properties under 980nm excitation and good stability in solution. Through epitaxial heterogeneous growth, a ∼4 nm optically inert β-NaYF4 shell was coated onto ∼5 nm ultrasmall Gd2O2S:20%Yb,1%Tm. These Gd2O2S:20%Yb,1%Tm@NaYF4 core/shell UCNPs exhibit a more than 800-fold increase in UCL intensity compared to the unprotected core, a 180-fold increase in luminescence decay time of the 3H4 → 3H6 Tm3+ transition from 5 to 900 μs, and an upconversion quantum yield (UCQY) of 0.76% at an excitation power density of 155 W/cm2. Likewise, Gd2O2S:20%Yb,2%Er@NaYF4 core/shell UCNPs show a nearly 5000-fold
increase of their UCL intensity compared to the Gd2O2S:20%Yb,2%Er core and a maximum UCQY of 0.61%. In the Yb/Er core−shell UCNP system, the observed variation of luminescence intensity ratio seems to originate from a change in lattice strain as the temperature is elevated. For nanothermometry applications, the thermal sensitivities based on thermally coupled levels are estimated for both Yb/Tm and Yb/Er doped Gd2O2S@NaYF4 core/shell UCNPs.
KW - Upconversion nanoparticle
KW - Nanosensor
KW - Lanthanide
KW - Surface coating
KW - Quantum yield
KW - Photophysic
PY - 2022
DO - https://doi.org/10.1021/acsnano.2c02423
SN - 1936-0851
SP - 1
EP - 11
PB - ACS Publications
AN - OPUS4-55440
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Henning, L. M.
A1 - Müller, J. T.
A1 - Smales, Glen Jacob
A1 - Pauw, Brian Richard
A1 - Schmidt, J.
A1 - Bekheet, M. F.
A1 - Gurlo, A.
A1 - Simon, U.
T1 - Hierarchically porous and mechanically stable monoliths from ordered mesoporous silica and their water filtration potential
N2 - Mechanically stable structures with interconnected hierarchical porosity combine the benefits of both small
and large pores, such as high surface area, pore volume, and good mass transport capabilities. Hence, lightweight micro-/meso-/macroporous monoliths are prepared from ordered mesoporous silica COK-12 by means of spark plasma sintering (SPS, S-sintering) and compared to conventionally (C-) sintered monoliths. A multi-scale model is developed to fit the small angle X-ray scattering data and obtain information on the hexagonal lattice parameters, pore sizes from the macro to the micro range, as well as the dimensions of the silica population. For both sintering techniques, the overall mesoporosity, hexagonal pore ordering, and amorphous character are preserved. The monoliths' porosity (77–49%), mesopore size (6.2–5.2 nm), pore volume (0.50–0.22 g cm-3
), and specific surface area (451–180 m2 g-1) decrease with increasing processing temperature and pressure. While the difference in porosity is enhanced, the
structural parameters between the C-and S-sintered monoliths are largely converging at 900 C, except for the mesopore size and lattice parameter, whose dimensions are more extensively preserved in the
S-sintered monoliths, however, coming along with larger deviations from the theoretical lattice. Their higher mechanical properties (biaxial strength up to 49 MPa, 724 MPa HV 9.807 N) at comparable porosities and ability to withstand ultrasonic treatment and dead-end filtration up to 7 bar allow S-sintered monoliths to reach a high permeance (2634 L m-2 h-1 bar-1), permeability (1.25 x 10^-14 m2), and ability to reduce the chemical oxygen demand by 90% during filtration of a surfactant-stabilized oil in water emulsion, while indicating reasonable resistance towards fouling.
KW - SAXS
KW - Hierarchically porous
KW - Silica
KW - Water filtration
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555928
DO - https://doi.org/10.1039/D2NA00368F
SN - 2516-0230
SP - 1
EP - 17
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-55592
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Falqueto, J. B.
A1 - Clark, A. H.
A1 - Štefančič, A.
A1 - Smales, Glen Jacob
A1 - Vaz, C. A. F.
A1 - Schuler, A. J.
A1 - Bocchi, N.
A1 - Kazzi, M. E.
T1 - High performance doped Li-rich Li1+xMn2–xO4 cathodes nanoparticles synthesized by facile, fast, and efficient microwave-assisted hydrothermal route
N2 - Li-rich nanoparticles of Li1+xMn2–xO4 doped with Al, Co, or Ni are successfully synthesized using a facile, fast, and efficient microwave-assisted hydrothermal route. Synchrotron X-ray diffraction confirms the formation of the crystalline cubic spinel phase type. X-ray absorption spectroscopy analysis at the Co and Ni K- and L-edges verifies that the dopants are within the Li1+xMn2–xO4 spinel structure and are inactive during cycling in the bulk and at the surface. Moreover, we demonstrate that nanocrystallinity and cationic doping play an important role in improving the electrochemical performance with respect to LiMn2O4 microparticles. They significantly reduce the charge-transfer resistance, lower the first cycle irreversible capacity loss to 6%, and achieve a capacity retention between 85 and 90% after 380 cycles, with excellent Coulombic efficiency close to 99% without compromising the specific charge at a 5C cycling rate. Furthermore, the Mn K- and L-edges attest that after long cycling, the Mn oxidation state in the bulk differs from that at the surface caused by the Mn disproportion reaction; however, the cationic doping helps mitigate the Mn dissolution with respect to the undoped Li1+xMn2–xO4 nanoparticles, as indicated by inductively coupled plasma atomic emission spectrometry.
KW - XAS
KW - SAXS
KW - Li-ion battery
KW - Cathode material
KW - Spinel
KW - The MOUSE
PY - 2022
DO - https://doi.org/10.1021/acsaem.2c00902
SN - 2574-0962
VL - 5
IS - 7
SP - 8357
EP - 8370
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-55359
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Topolniak, Ievgeniia
A1 - Elert, Anna Maria
A1 - Knigge, Xenia
A1 - Ciftci, G. C.
A1 - Radnik, Jörg
A1 - Sturm, Heinz
T1 - High precision micropatterning of polydopamine by Multiphoton Lithography
N2 - Mussel-inspired polydopamine (PDA) initiated a multifunctional modification route that leads to the generation of novel advanced materials and their applications. However, existing PDA deposition techniques still exhibit poor spatial control, have a very limited capability of micropatterning and do not allow to locally tune PDA topography. Herein, we demonstrate PDA deposition based on Multiphoton Lithography (MPL) that enables full spatial and temporal control with nearly total freedom of patterning design. Using MPL, we achieve 2D microstructures of complex design with pattern precision of 0.8 μm without the need of a photomask or stamp. Moreover, this approach permits adjusting the morphology and thickness of the fabricated microstructure within one deposition step, resulting in a unique tunability of materials properties. The chemical composition of PDA is confirmed and its ability for protein enzyme immobilization is demonstrated. This work presents a new methodology for high precision and complete control of PDA deposition, enabling PDA incorporation in applications where fine and precise local surface functionalization is required. Possible applications include multicomponent functional elements and devices in microfluidics or lab-on-a-chip systems.
KW - Multiphoton lithography
KW - Polydopamine
KW - Micropatterning
PY - 2022
DO - https://doi.org/10.1002/adma.202109509
VL - 34
IS - 18
SP - e2109509
PB - Wiley online library
AN - OPUS4-54535
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ziesche, R.F.
A1 - Hack, J.
A1 - Rasha, L.
A1 - Maier, M.
A1 - Tan, C.
A1 - Heenan, T.M.M.
A1 - Markötter, Henning
A1 - Kardjilov, N.
A1 - Manke, I.
A1 - Kockelmann, W.
A1 - Brett, D.J.L.
A1 - Shearing, P.R.
T1 - High-speed 4D neutron computed tomography for quantifying water dynamics in polymer electrolyte fuel cells
N2 - In recent years, low-temperature polymer electrolyte fuel cells have become an increasingly important pillar in a zero-carbon strategy for curbing climate change, with their potential to power multiscale stationary and mobile applications. The performance improvement is a particular focus of research and engineering roadmaps, with water management being one of the major areas of interest for development. Appropriate characterisation tools for mapping the evolution, motion and removal of water are of high importance to tackle shortcomings.
This article demonstrates the development of a 4D high-speed neutron imaging technique, which enables a quantitative analysis of the local water evolution. 4D visualisation allows the time-resolved studies of droplet formation in the flow fields and water quantification in various cell parts. Performance parameters for water management are identified that offer a method of cell classification, which will, in turn, support computer modelling and the engineering of next-generation flow field designs.
KW - Neutron imaging
KW - Tomography
KW - Polymer electrolyte membrane fuel cell
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545978
DO - https://doi.org/10.1038/s41467-022-29313-5
VL - 13
IS - 1
SP - 1616
PB - Nature Publishing Group UK
CY - London
AN - OPUS4-54597
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Porta-Velilla, L.
A1 - Turan, N.
A1 - Cubero, Á.
A1 - Shao, W.
A1 - Li, H.
A1 - de la Fuente, G.F.
A1 - Martínez, E.
A1 - Larrea, Á.
A1 - Castro, M.
A1 - Koralay, H.
A1 - Çavdar, Ş.
A1 - Bonse, Jörn
A1 - Angurel, L.A.
T1 - Highly Regular Hexagonally-Arranged Nanostructures on Ni-W Alloy Tapes upon Irradiation with Ultrashort UV Laser Pulses
N2 - Nickel tungsten alloy tapes (Ni—5 at% W, 10 mm wide, 80 µm thick, biaxially textured) used in second-generation high temperature superconductor (2G-HTS) technology were laser-processed in air with ultraviolet ps-laser pulses (355 nm wavelength, 300 ps pulse duration, 250–800 kHz pulse repetition frequency). By employing optimized surface scan-processing strategies, various laser-generated periodic surface structures were generated on the tapes. Particularly, distinct surface microstructures and nanostructures were formed. These included sub-wavelength-sized highly-regular hexagonally-arranged nano-protrusions, wavelength-sized line-grating-like laser-induced periodic surface structures (LIPSS, ripples), and larger irregular pyramidal microstructures. The induced surface morphology was characterized in depth by electron-based techniques, including scanning electron microscopy (SEM), electron back scatter diffraction (EBSD), cross-sectional transmission electron microscopy (STEM/TEM) and energy dispersive X-ray spectrometry (EDS). The in-depth EBSD crystallographic analyses indicated a significant impact of the material initial grain orientation on the type of surface nanostructure and microstructure formed upon laser irradiation. Special emphasis was laid on high-resolution material analysis of the hexagonally-arranged nano-protrusions. Their formation mechanism is discussed on the basis of the interplay between electromagnetic scattering effects followed by hydrodynamic matter re-organization after the laser exposure. The temperature stability of the hexagonally-arranged nano-protrusion was explored in post-irradiation thermal annealing experiments, in order to qualify their suitability in 2G-HTS fabrication technology with initial steps deposition temperatures in the range of 773–873 K.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Ultrashort laser processing
KW - Hexagonally-arranged nano-protrusions
KW - Second-generation high temperature superconductor technology
KW - Electron microscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552551
DO - https://doi.org/10.3390/nano12142380
SN - 2079-4991
VL - 12
IS - 14
SP - 1
EP - 23
PB - MDPI
CY - Basel, Switzerland
AN - OPUS4-55255
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Rhode, Michael
A1 - Nietzke, Jonathan
A1 - Richter, Tim
T1 - Hydrogen diffusion and desorption characteristics of a CoCrFeMnNi high entropy and a CoCrNi medium entropy alloy
N2 - High-entropy alloys (HEAs) are innovative high-performance materials that have attracted more and more research attention. HEAs are characterized by a solid solution of typically five equiatomic metallic elements. In addition, medium-entropy alloys (MEA, with three elements) are of interest and become more and more important. Depending on the alloy concept, HEAs and MEAs show exceptional mechanical properties, especially high-strength and ductility combinations at both cryogenic and elevated temperatures combined with excellent corrosion resistance. Future structural HEA/MEA components can be exposed to potential applications with hydrogen containing environments like high-temperature water in pressurized nuclear reactors or aerospace structures. Other potential applications could be in materials for vessel walls in the field of cryogenic and high-pressure hydrogen storage. So far, the susceptibility of HEAs/MEAs to hydrogen assisted cracking (if any) and the hydrogen diffusion is not investigated in detail yet and can limit or extend possible applications of HEA/MEA as structural materials. In our work, we focused on the hydrogen absorption, diffusion, and distribution in a HEA (CoCrFeMnNi the original Cantor-alloy) and a MEA (CoCrNi). Cathodic hydrogen charging was carried out for the hydrogen ingress, and thermal desorption analysis (TDA) revealed complex hydrogen trapping in both alloy types up to 300 °C. The absorbed total hydrogen concentrations were > 100 ppm for the HEA and > 40 ppm for MEA. In addition, the assessment of the peak deconvolution is not trivial and must consider both experimental and microstructure influences.
T2 - 4th International Conference on Metals and Hydrogen - Steely & Hydrogen 2022
CY - Ghent, Belgium
DA - 11.10.2022
KW - Hydrogen
KW - High-entropy alloy
KW - Multiple principal element alloy
KW - Thermal desorption analysis
KW - Diffusion
PY - 2022
SP - 1
EP - 11
CY - Ghent, Belgium
AN - OPUS4-56076
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhao, H.
A1 - Chakraborty, Poulami
A1 - Ponge, D.
A1 - Hickel, Tilmann
A1 - Sun, B.
A1 - Wu, C.-H.
A1 - Gault, B.
A1 - Raabe, D.
T1 - Hydrogen trapping and embrittlement in high-strength Al alloys
N2 - Ever more stringent regulations on greenhouse gas emissions from transportation motivate efforts to revisit materials used for vehicles. High-strength aluminium alloys often used in aircrafts could help reduce the weight of automobiles, but are susceptible to environmental degradation. Hydrogen ‘embrittlement’ is often indicated as the main culprit; however, the exact mechanisms underpinning failure are not precisely known: atomic-scale analysis of H inside an alloy remains a challenge, and this prevents deploying alloy design strategies to enhance the durability of the materials. Here we performed near-atomic-scale analysis of H trapped in second-phase particles and at grain boundaries in a high-strength 7xxx Al alloy. We used these observations to guide atomistic ab initio calculations, which show that the co-segregation of alloying elements and H favours grain boundary decohesion, and the strong partitioning of H into the second-phase particles removes solute H from the matrix, hence preventing H embrittlement. Our insights further advance the mechanistic understanding of H-assisted embrittlement in Al alloys, emphasizing the role of H traps in minimizing cracking and guiding new alloy design.
KW - Atomistic models
KW - Hydrogen
KW - Metals and alloys
KW - Mechanical properties
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543631
DO - https://doi.org/10.1038/s41586-021-04343-z
SN - 1476-4687
VL - 602
IS - 7897
SP - 437
EP - 441
PB - Nature Publ. Group
CY - London
AN - OPUS4-54363
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Erning, Johann Wilhelm
ED - Leyens, C.
T1 - Hygienische Eigenschaften von additiv gefertigtem 1.4404 in Trinkwasser
N2 - Elektrochemische Messungen zur hygienischen Bewertung additiv gefertigter Bauteile werden diskutiert. Die Bewertung und Details des Werkstoffs werden beschrieben, Anwendungsbeispiele werden gezeigt.
T2 - 3. Fachtagung Werkstoffe und Additive Fertigung
CY - Dresden, Germany
DA - 11.05.2022
KW - Korrosion
KW - Trinkwasser
KW - Hygienische Bewertung
KW - Additive Fertigung
PY - 2022
SN - 978-3-88355-423-2
SP - 126
EP - 127
PB - Deutsche Gesellschaft für Materialkunde (DGM)
CY - Sankt Augustin
AN - OPUS4-54933
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Boyraz, B.
A1 - Saatz, Jessica
A1 - Pompös, I.-M.
A1 - Gad, Michel
A1 - Dernedde, J.
A1 - Maier, A.-M. B.
A1 - Moscovitz, O.
A1 - Seeberger, P. H.
A1 - Traub, Heike
A1 - Tauber, R.
T1 - Imaging Keratan Sulfate in Ocular Tissue Sections by Immunofluorescence Microscopy and LA-ICP-MS
N2 - Carbohydrate-specific antibodies can serve as valuable tools to monitor alterations in the extracellular matrix resulting from pathologies. Here, the keratan sulfate-specific monoclonal antibody MZ15 was characterized in more detail by immunofluorescence microscopy as well as laser ablation ICP-MS using tissue cryosections and paraffin-embedded samples. Pretreatment with keratanase II prevented staining of samples and therefore demonstrated efficient enzymatic keratan sulfate degradation. Random fluorescent labeling and site-directed introduction of a metal cage into MZ15 were successful and allowed for a highly sensitive detection of the keratan sulfate landscape in the corneal stroma from rats and human tissue.
KW - Laser ablation
KW - Imaging
KW - Glycosaminoglycan
KW - ICP-MS
KW - Immunohistochemistry
KW - Immunofluorescence
KW - Tissue
PY - 2022
DO - https://doi.org/10.1021/acsabm.1c01240
VL - 5
IS - 2
SP - 853
EP - 861
PB - American Chemical Society
CY - Washington
AN - OPUS4-54341
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Climent Terol, Estela
A1 - Weller, Michael G.
A1 - Martínez-Mánez, R.
A1 - Rurack, Knut
T1 - Immunochemical design of antibody-gated indicator delivery (gAID) systems based on mesoporous silica nanoparticles
N2 - In this work, the optimization of the immunochemical response of antibody-gated indicator delivery (gAID) systems prepared with mesoporous silica nanoparticles has been studied along various lines of system tailoring, targeting the peroxide-type explosive TATP as an exemplary analyte. The mechanism of detection of these gAID systems relies on a displacement of an antibody “cap” bound to hapten derivatives anchored to the surface of a porous hybrid material, allowing the indicator cargo stored in the mesopores to escape and massively amplify the analyte-related signal. Since our aim was to obtain gAID systems with the best possible response in terms of sensitivity, selectivity, and assay time, sera obtained from different immunization boosts were screened, the influence of auxiliary reagents was assessed, structural hapten modification (hapten heterology) was investigated, and various indicator dyes and host materials were tested. Considering that highly selective and sensitive immunological responses are best obtained with high-affinity antibodies which, however, could possess rather slow dissociation constants, leading to slow responses, the main challenge was to optimize the immunochemical recognition system for a rapid response while maintaining a high sensitivity and selectivity. The best performance was observed by grafting a slightly mismatching (heterologous) hapten to the surface of the nanoparticles in combination with high-affinity antibodies as “caps”, yielding for the first time gAID nanomaterials for which the response time could be improved from hours to <5 min. The materials showed favorable detection limits in the lower ppb range and discriminated TATP well against H2O2 and other explosives. Further optimization led to straightforward integration of the materials into a lateral flow assay without further treatment or conditioning of the test strips while still guaranteeing remarkably fast overall assay times.
KW - Antibody-gated indicator delivery systems
KW - Signal amplification
KW - Immunochemical response optimization
KW - Test strip analysis
KW - TATP
KW - Explosives detection
KW - Heterologous hapten
PY - 2022
DO - https://doi.org/10.1021/acsanm.1c03417
SN - 2574-0970
VL - 5
IS - 1
SP - 626
EP - 641
PB - American Chemical Society
CY - Washington, DC
AN - OPUS4-54176
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Usmani, S.
A1 - Voss, L.
A1 - Stephan, Ina
A1 - Hübert, Thomas
A1 - Kemnitz, E.
T1 - Improved Durability of Wood Treated with Nano Metal Fluorides against Brown-Rot and White-Rot Fungi
N2 - Low-water soluble metal fluorides such as magnesium fluoride (MgF2) and calcium Fluoride (CaF2) were evaluated for decay protection of wood. Initially, the biocidal efficacy of nano metal fluorides (NMFs) against wood destroying fungi was assessed with an in-vitro agar test. The results from the test showed that agar medium containing MgF2 and CaF2 was more efficient in preventing fungal decay than stand-alone MgF2 or CaF2. These metal fluorides, in their nanoscopic form synthesized using fluorolytic sol-gel synthesis, were introduced into the sapwood of Scots pine and beech wood and then subjected to accelerated ageing by leaching (EN 84). MAS 19F NMR and X-ray micro CT images showed that metal fluorides were present in treated wood, unleached and leached. Decay resistance of Scots pine and beech wood treated with NMFs was tested against Wood destroying fungi Rhodonia placenta and Trametes versicolor in accordance with EN 113. Results revealed that mass losses were reduced to below 3% in wood treated with the combination of MgF2 and CaF2.
It is concluded that NMFs provide full protection to wood even after it has been leached and can be used as wood preservatives in outdoor environments.
KW - Nanoparticles
KW - Fluoride
KW - Wood protection
KW - Fluorolytic sol-gel synthesis
KW - Brown-rot fungi
KW - White-rot fungi
KW - Basidiomycetes
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543877
DO - https://doi.org/10.3390/app12031727
VL - 12
IS - 3
SP - 1
EP - 11
PB - MDPI
AN - OPUS4-54387
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chambers, M. S.
A1 - Hunter, R. D.
A1 - Hollamby, M. J.
A1 - Pauw, Brian Richard
A1 - Smith, A. J.
A1 - Snow, T.
A1 - Danks, A. E.
A1 - Schnepp, Z.
T1 - In Situ and Ex Situ X‑ray Diffraction and Small-Angle X‑ray Scattering Investigations of the Sol−Gel Synthesis of Fe3N and Fe3C
N2 - Iron nitride (Fe3N) and iron carbide (Fe3C) nanoparticles can be prepared via sol−gel synthesis. While sol−gel methods are simple, it can be difficult to control the crystalline composition, i.e., to achieve a Rietveld-pure product. In a previous in situ synchrotron study of the sol−gel synthesis of Fe3N/Fe3C, we showed that the reaction proceeds as follows:
Fe3O4 → FeOx → Fe3N → Fe3C. There was considerable overlap between the different phases, but we were unable to ascertain whether this was due to the experimental setup (side-on heating of a quartz capillary which could lead to thermal gradients) or whether individual particle reactions proceed at different rates. In this paper, we use in situ wide- and small-angle X-ray scattering (wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS)) to demonstrate that the overlapping phases are indeed due to variable reaction rates. While the initial oxide nanoparticles have a small range of diameters, the size range expands considerably and very rapidly during the oxide−nitride transition. This has implications for the isolation of Rietveld-pure Fe3N, and in an extensive laboratory study, we were indeed unable to isolate phasepure Fe3N. However, we made the surprising discovery that Rietveld-pure Fe3C nanoparticles can be produced at 500 °C with a sufficient furnace dwell time. This is considerably lower than the previous reports of the sol−gel synthesis of Fe3C nanoparticles.
KW - Small-angle X-ray Scattering
KW - SAXS
KW - Diffraction
KW - XRD
KW - Scattering
KW - Sol-gel
KW - Iron nitride
KW - Nanoparticles
KW - Iron carbide
KW - Catalyst
KW - In-situ
KW - Ex-situ
KW - Synthesis
KW - Synchrotron
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548226
DO - https://doi.org/10.1021/acs.inorgchem.1c03442
VL - 61
IS - 18
SP - 6742
EP - 6749
PB - ACS Publications
CY - Washington
AN - OPUS4-54822
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Almalla, A.
A1 - Özcan Sandikcioglu, Özlem
A1 - Witt, Julia
T1 - In Situ Atomic Force Microscopy Analysis of the Corrosion Processes at the Buried Interface of an Epoxy-like Model Organic Film and AA2024-T3 Aluminum Alloy
N2 - The application of characterization methods with high spatial resolution to the analysis of buried coating/metal interfaces requires the design and use of model systems. Herein, an epoxy-like thin film is used as a model coating resembling the epoxy-based coatings and adhesives widely used in technical applications. Spin coating is used for the deposition of a 30 nm-thin bilayer (BL) composed of poly-(ethylenimine) (PEI) and poly[(o-cresyl glycidyl ether)-co-formaldehyde] (CNER). Fourier-transform infrared spectroscopy (FTIR) results confirm that the exposure of coated AA2024-T3 (AA) samples to the corrosive electrolyte solution does not cause the degradation of the polymer layer. In situ atomic force microscopy (AFM) studies are performed to monitor local corrosion processes at the buried interface of the epoxy-like film and the AA2024-T3 aluminum alloy surface in an aqueous electrolyte solution. Hydrogen evolution due to the reduction of water as the cathodic corrosion reaction leads to local blister formation. Based on the results of the complementary energy-dispersive X-ray spectroscopy (EDX) analysis performed at the same region of interest, most of the hydrogen evolved originates at the vicinity of Mg-containing intermetallic particles.
KW - Scanning Kelvin probe force microscopy
KW - Aluminum alloys
KW - Buried interfaces
KW - In situ atomic force microscopy
KW - Local corrosion
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546932
DO - https://doi.org/10.1002/adem.202101342
SN - 1438-1656
SP - 1
EP - 9
PB - Wiley VHC-Verlag
AN - OPUS4-54693
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -