TY - JOUR
A1 - Göbel, M.
A1 - Kirsch, S.
A1 - Schwarze, L:
A1 - Schmidt, L.
A1 - Scholz, H.
A1 - Haußmann, J.
A1 - Klages, M.
A1 - Scholta, J.
A1 - Markötter, H.
A1 - Alrwashdeh, S.
A1 - Manke, I.
A1 - Müller, Bernd R.
T1 - Transient limiting current measurements for characterization of gas diffusion layers
N2 - The water management in proton exchange membrane fuel cells (PEMFC) is strongly influenced by the design of the gas diffusion layers (GDL). Limiting current measurements in small-scale cells operating at high stoichiometries are useful to determine the oxygen transport resistance. The oxygen transport resistance increases, once water condenses inside the GDL. In this study a new electrochemical method for voltage loss estimation of GDL induced oxygen transport losses are presented. This new method, referred to as “transient limiting current” (TLC), is compared with the literature method. TLC allows a direct estimation of oxygen transport resistance at an arbitrarily conditioned state. This study also presents a case study of liquid water visualization of a PEM fuel cell with varying GDLs types.
With the help of quasi in-situ synchrotron X-ray computed tomography and time resolved radiography measurements we investigate appearance and distribution of liquid water inside the GDLs under limiting current conditions.
KW - In-situ characterization of GDLs
KW - In-situ synchrotron X-ray computed tomography
KW - In-situ synchrotron X-ray radiography
KW - BAMline
PY - 2018
DO - https://doi.org/10.1016/j.jpowsour.2018.09.003
SN - 0378-7753
SN - 1873-2755
VL - 402
SP - 237
EP - 245
PB - Elsevier B.V.
AN - OPUS4-46552
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Deubener, J.
A1 - Allix, M.
A1 - Davis, M.J.
A1 - Duran, A.
A1 - Höche, T.
A1 - Honma, T.
A1 - Komatsu, T.
A1 - Krüger, S.
A1 - Mitra, I.
A1 - Müller, Ralf
A1 - Nakane, S.
A1 - Pascual, M.J.
A1 - Schmelzer, J.W.
A1 - Zanotto, E.D.
A1 - Zhou, S.
T1 - Updated definition of glass-ceramics
N2 - Glass-ceramics are noted for their unusual combination of properties and manifold commercialized products for consumer and specialized markets. Evolution of novel glass and ceramic processing routes, a plethora of new compositions, and unique exotic nano- and microstructures over the past 60 years led us to review the Definition of glass-ceramics. Well-established and emerging processing methods, such as co-firing, additive manufacturing, and laser patterning are analyzed concerning the core requirements of processing glass-ceramics and the Performance of the final products. In this communication, we propose a revised, updated definition of glass-ceramics, which reads “Glass-ceramics are inorganic, non-metallic materials prepared by controlled crystallization of glasses via different processing methods. They contain at least one type of functional crystalline phase and a residual glass. The volume fraction crystallized may vary from ppm to almost 100%”.
KW - Glass-ceramics definition
PY - 2018
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-464711
DO - https://doi.org/10.1016/j.jnoncrysol.2018.01.033
SN - 0022-3093
SN - 1873-4812
VL - 501
SP - 3
EP - 10
PB - Elsevier B.V.
AN - OPUS4-46471
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, I.
A1 - Moll, J.
A1 - Kexel, C.
A1 - Schubert, L.
A1 - Tschöke, K.
A1 - Prager, Jens
A1 - Lugovtsova, Yevgeniya
A1 - Bach, M.
A1 - Vogt, T.
T1 - SHM using Guided Waves – Recent Activities and Advances in Germany
N2 - Issues that prevent Structural Health Monitoring (SHM) based on Guided Waves (GW) from being a part of today’s monitoring solutions in industry are not all obvious to the scientific community. To uncover and overcome these issues, scientists working on SHM and GW problems joined in an expert committee under the patronage of the German Society for Non-Destructive Testing. An initiated online survey among more than 700 experts and users reveals the hurdles hindering the practical application of GWbased SHM. Firstly, methods for proof of reliability of SHM approaches are missing.
Secondly, detailed understanding of phenomenological described wave-damage interactions is needed. Additionally, there are significant unsolved implementation issues and unsolved problems of signal processing including handling of environmental influences.
To enable substantial proof of reliability without unaffordable experimental effort also efficient simulation tools including realistic damage interaction are needed, enabling the joint use of experimental and simulated data to predict the capabilities of the Monitoring system. Considering these issues, the committee focusses on simulation, signal processing, as well as probability of detection and standardization. In the presented work, recent activities of the expert committee starting with survey results are summarized. An open access data basis of life-like measurements is presented to allow testing and comparison of signal processing and simulation algorithms. Finally, a strategy for efficient proof of reliability increasing the acceptance of SHM in industry and for successful Integration of SHM into real-world engineering structures is proposed.
T2 - The 12th International Workshop on Structural Health Monitoring (IWSHM)
CY - Stanford, California, USA
DA - 10.09.2019
KW - Structural Health Monitoring
KW - Ultrasonic Guided Waves
KW - Non-Destructive Testing
KW - Survey
KW - Probability of Detection
KW - Reliability
PY - 2019
SP - 1
EP - 10
AN - OPUS4-49232
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Welter, T.
A1 - Marzok, Ulrich
A1 - Deubener, J.
A1 - Reinsch, Stefan
A1 - Müller, Ralf
T1 - Hydrogen diffusivity in sodium aluminosilicate glasses
N2 - Hydrogen gas diffusivity of fourteen glasses of the Na2O-Al2O3-SiO2 system are studied along the joins quartzalbite-jadeite-nepheline (Qz-Ab-Jd-Np, fully polymerized) and albite-sodium disilicate (Ab-Ds, depolymerized).
Density measurements show that ionic porosity decreases from 54.4% (Qz) to 51.5% (Np) and from 52.4% (Ab) to 50.2% (Ds). Hydrogen diffusivity D follows similar trends but at another scale. D at 523 K decreases from 4×10−12 to 3×10−14m2 s−1 (Qz-Np) and from 4×10−13 to 3×10−15m2 s−1 (Ab-Ds). Charge compensating Na+ acting as a filling agent in fully polymerized network structures leads to up to one order of Magnitude higher diffusivities as depolymerized glass structures of the same SiO2 content where Na+ takes the role of a
modifier ion. Temperature dependence of the diffusivity indicates that both the activation energy involved with the moving H2 molecule as well as the accessible volume in the structure contribute to this compositional trend.
KW - Aluminosilicate glasses
KW - Hydrogen diffusivity
KW - Ionic porosity
PY - 2019
DO - https://doi.org/10.1016/j.jnoncrysol.2019.119502
VL - 521
SP - 119502
PB - Elsevier B.V.
AN - OPUS4-50392
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kiefer, P.
A1 - Deubener, J.
A1 - Müller, Ralf
A1 - Behrens, H.
T1 - Statistical analysis of propagation rates of indentation-induced radial cracks
N2 - Due to the stochastic nature of crack nucleation by Vickers indentation, a statistical analysis of propagation rates of 185 radial cracks was performed. Crack growth was observed directly using a video camera with high Image acquisition rate. It is found that propagation rates are controlled by the environmental reactions at the crack-tip shortly after their initiation (< 1 s). Calibration of the stress intensity KI showed that the residual stress factor χ and the exponent n of the equation KI==χPc−n (with P==load and c==crack length) are broadly distributed among the 185 analyzed cracks, ranging from 10−16 to 104 and from 0.1 to 5, respectively. For the most frequent crack, the equation KI==0.052Pc−1.47 holds. The results show that correlations of indentation-induced crack length to stress intensity necessitate the use of statistical significant data that are calibrated by the environmental reactions at the crack-tip.
KW - Stress intensity factor
KW - Vickers indentation
KW - Subcritical crack growth
KW - Soda-lime-silica glass
PY - 2019
DO - https://doi.org/10.1016/j.jnoncrysol.2019.119739
VL - 527
SP - 119739
PB - Elsevier B.V.
AN - OPUS4-50393
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Balzer, R.
A1 - Behrens, H.
A1 - Schuth, S.
A1 - Waurischk, Tina
A1 - Reinsch, Stefan
A1 - Müller, Ralf
A1 - Fechtelkord, M.
A1 - Deubener, J.
T1 - The influence of H2O and SiO2 on the structure of silicoborate glasses
N2 - To understand the impact of dissolved water on structure and properties, four boron-rich glasses of molar compositions 15-x Na2O x CaO 15 SiO2 70 B2O3 (with x=0, 7.5, 10) and 10 Na2O 15 SiO2 75 B2O3 were prepared and subsequently hydrated (up to 8 wt% H2O). Density measurements show a non-linear trend upon hydration implying large structural changes in particular at water contents<2 wt%. Near-infrared spectroscopy shows hydroxyl groups are the dominant species in all glasses upon the entire range of water content. Molecular H2O is detectable only at total water contents>2 wt%. 11B MAS NMR spectra show that the abundance of BO4 species is mainly controlled by ratio of (Na2O+CaO)/B2O3 while incorporation of water plays a minor role.
Compared to borate glasses, the efficiency of formation of BO4 tetrahedra is favored by crosslinking of the network by SiO4-units. The glass transition temperatures, determined by differential thermal analysis, decreases continuously with water content due to breakage of B-O-B bonds by hydrolysis. However, compared to Silicates and aluminosilicates, the effect of dissolved water is less pronounced which can be explained by weaker B-O-B bonds in comparison to Si-O-Si bonds.
KW - High pressure
KW - Water speciation
KW - Silicoborate glasses
KW - Infrared spectroscopy
KW - NMR spectroscopy
PY - 2019
DO - https://doi.org/10.1016/j.jnoncrysol.2019.05.030
VL - 519
SP - 38
EP - 51
PB - Elsevier B.V.
AN - OPUS4-48748
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kiefer, P.
A1 - Balzer, R.
A1 - Deubener, J.
A1 - Behrens, H.
A1 - Waurischk, Tina
A1 - Reinsch, Stefan
A1 - Müller, Ralf
T1 - Density, elastic constants and indentation hardness of hydrous soda-lime silica glasses
N2 - The effect of structural water on density, elastic constants and microhardness of water-bearing soda-lime-silica glasses of up to 21.5 mol% total water is studied. It is found that the Poisson ratio and the water content are positively correlated, while density and the elastic moduli decrease with increasing water content. Vickers hardness decreases by approximately 27% from the dry to the most hydrous glass. For water fractions <3 mol%, the dependencies are non-linear reflecting the non-linear change in the concentrations of OH and H2O molecules dissolved, whereas for water fractions >3 mol% linear dependencies are found. To distinguish the effect of structural water and environmental water, indentations were performed in toluene, nitrogen gas and air. Timedependent softening was evident for testing dry glasses in humid atmospheres as well as for tests of hydrous glasses in dry atmospheres. This indicates that the response times of dissolved water species are effectively equal in both scenarios.
KW - Elastic constants
KW - Soda-lime-silica
KW - Glass
KW - Water content
KW - Microhardness
PY - 2019
DO - https://doi.org/10.1016/j.jnoncrysol.2019.119480
SN - 0022-3093
SN - 1873-4812
VL - 521
SP - 119480
PB - Elsevier B.V.
AN - OPUS4-48758
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, U.
A1 - McMahon, Dino Peter
A1 - Rolff, J.
T1 - Exposure of the wild bee Osmia bicornis to the honey bee pathogen Nosema ceranae
N2 - Wild bees are important pollinators for agricultural crops and solitary species such as Osmia bicornis are particularly suitable for pollination management. Wild bees share floral resources with managed honey bees and may be exposed to emerging infectious diseases. Although studies have explored the prevalence of pathogens in solitary wild bee species, data regarding the impact of pathogens on solitary bee health are lacking.
We carried out experiments examining whether the solitary bee species O. bicornis is susceptible to infection with the emerging pathogen The results obtained indicate that N. ceranae may be able to infect O. bicornis but its impact on host fitness is negligible: survival rates did not differ between Control and inoculated bees, although male survival was marginally lower after infection. To explore the possible field-relevance of our findings, we collected wild bees near an infected and a non-infected hive and showed that N. ceranae was shared between managed and wild bees, although only the in presence of infected honey bees.
The findings of the present study show that O. bicornis is susceptible to pathogen spillover and could act as a potential reservoir host for N. ceranae in pollinator networks. Additional studies on this species incorporating sublethal effects, multiple infections and other interacting stressors are warranted.
KW - Wild bees
KW - Nosema ceranae
KW - Osmia bicornis
KW - Pathogen spillover
KW - Survival rates
PY - 2019
DO - https://doi.org/10.1111/afe.12338
SN - 1461-9555
SN - 1461-9563
VL - 21
IS - 4
SP - 363
EP - 371
PB - Wiley
AN - OPUS4-49648
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bramke, K.
A1 - Müller, U.
A1 - McMahon, Dino Peter
A1 - Rolff, J.
T1 - Exposure of Larvae of the Solitary Bee Osmia bicornis to the Honey Bee Pathogen Nosema ceranae Aects Life History
N2 - Wild bees are important pollinators of wild plants and agricultural crops and they are threatened by several environmental stressors including emerging pathogens. Honey bees have been suggested as a potential source of pathogen spillover. One prevalent pathogen that has recently emerged as a honey bee disease is the microsporidian Nosema ceranae. While the impacts of N. ceranae in honey bees are well documented, virtually nothing is known about its effects in solitary wild bees.
The solitary mason bee Osmia bicornis is a common pollinator in orchards and amenable to Commercial management. Here, we experimentally exposed larvae of O. bicornis to food contaminated with N. ceranae and document spore presence during larval development. We measured mortality, growth parameters, and timing of pupation in a semi-field experiment. Hatched individuals were assessed for physiological state including fat body mass, wing muscle mass, and body size. We recorded higher mortality in the viable-spore-exposed group but could only detect a low number of Spores among the individuals of this treatment. Viable-spore-treated individuals with higher head capsule width had a delayed pupation start. No impact on the physiological status could be detected in hatched imagines. Although we did not find overt evidence of O. bicornis infection, our findings indicate that exposure of larvae to viable N. ceranae spores could affect bee development.
KW - Bee diseases
KW - Wild bees
KW - Nosema ceranae
KW - Osmia bicornis
KW - Pathogen transmission
KW - Solitary bees
KW - Bee health
PY - 2019
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-496497
DO - https://doi.org/10.3390/insects10110380
VL - 10
IS - 11
SP - 380
PB - MDPI
AN - OPUS4-49649
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kiefer, P.
A1 - Maiwald, M.
A1 - Deubener, J.
A1 - Balzer, R.
A1 - Behrens, H.
A1 - Waurischk, Tina
A1 - Reinsch, Stefan
A1 - Müller, Ralf
T1 - Automated Analysis of Slow Crack Growth in Hydrous Soda-Lime Silicate Glasses
N2 - To explore the impact of ambient and structural water on static fatigue, the initiation and growth of 3279 Vickers induced median radial cracks were automatically recorded and analyzed. We find that humidity is more efficient in initiating cracks and promoting their growth than water, which is dissolved in the glass structure. In particular for slow crack growth (< 3x10-6 m s-1), tests in dry nitrogen showed a considerable decrease in the crack growth exponent with increasing water content of the glasses. On the other hand, if tests were performed in humid air, the crack growth exponent was independent of the water content of the hydrous glasses, while stress intensity decreased slightly. These observations indicate that water promotes the processes at the crack-tip regardless of its origin. However, ambient water is more efficient.
KW - Indentation fracture toughness
KW - Slow crack growth
KW - Automated analysis
KW - Hydrous glass
KW - Vickers indentation
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513085
DO - https://doi.org/10.3389/fmats.2020.00268
VL - 7
SP - 268
AN - OPUS4-51308
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Denißen, M.
A1 - Hannen, R.
A1 - Itskalov, D.
A1 - Biesen, L.
A1 - Nirmalananthan-Budau, Nithiya
A1 - Hoffmann, Katrin
A1 - Reiss, G. J.
A1 - Resch-Genger, Ute
A1 - Müller, T. J. J.
T1 - One-pot synthesis of a white-light emissive bichromophore operated by aggregation-induced dual emission (AIDE) and partial energy transfer
N2 - Merocyanine–triarylamine bichromophores are readily synthesized by sequentially Pd-catalyzed insertion alkynylation–Michael–Suzuki four-component reactions. White-light emissive systems form upon aggregation in 1 : 99 and 0.1 : 99.9 vol% CH2Cl2–cyclohexane mixtures, ascribed to aggregation-induced dual emission (AIDE) in combination with partial energy transfer between both chromophore units as supported by spectroscopic studies.
KW - Energy transfer
KW - Nano
KW - Nanoparticle
KW - Photoluminescence
KW - Fluorescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - Dye
KW - Enhancement
KW - Particle
KW - Polarity
KW - AIE
KW - Aggregation
KW - Aggregation-induced emission
KW - Solid state emission
KW - Merocyanine
PY - 2020
DO - https://doi.org/10.1039/d0cc03451g
VL - 56
IS - 54
SP - 7407
PB - Royal Society of Chemistry
AN - OPUS4-50936
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Faghani, A.
A1 - Gholami, M. F.
A1 - Trunk, M.
A1 - Müller, J.
A1 - Pachfule, P.
A1 - Vogl, S.
A1 - Donskyi, Ievgen
A1 - Li, M.
A1 - Nickl, Philip
A1 - Shao, J.
A1 - Huang, M. R. S.
A1 - Unger, Wolfgang
A1 - Arenal, R.
A1 - Koch, C. T.
A1 - Paulus, B.
A1 - Rabe, J. P.
A1 - Thomas, A.
A1 - Haag, R.
A1 - Adeli, M.
T1 - Metal-Assisted and Solvent-Mediated Synthesis of Two-Dimensional Triazine Structures on Gram Scale
N2 - Covalent triazine frameworks are an emerging material class that have shown promising performance for a range of applications. In this work, we report on a metal-assisted and solvent-mediated reaction between calcium carbide and cyanuric chloride, as cheap and commercially available precursors, to synthesize two-dimensional triazine structures (2DTSs). The reaction between the solvent, dimethylformamide, and cyanuric chloride was promoted by calcium carbide and resulted in dimethylamino-s-triazine intermediates, which in turn undergo nucleophilic substitutions. This reaction was directed into two dimensions by calcium ions derived from calcium carbide and induced the formation of 2DTSs. The role of calcium ions to direct the two-dimensionality of the final structure was simulated using DFT and further proven by synthesizing molecular intermediates. The water content of the reaction medium was found to be a crucial factor that affected the structure of the products dramatically. While 2DTSs were obtained under anhydrous conditions, a mixture of graphitic material/2DTSs or only graphitic material (GM) was obtained in aqueous solutions. Due to the straightforward and gram-scale synthesis of 2DTSs, as well as their photothermal and photodynamic properties, they are promising materials for a wide range of future applications, including bacteria and virus incapacitation.
KW - XPS
KW - Triazine
KW - 2D
PY - 2020
DO - https://doi.org/10.1021/jacs.0c02399
VL - 142
IS - 30
SP - 12976
EP - 12986
PB - ACS American Chemical Society
AN - OPUS4-51203
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Herzel, Hannes
A1 - Dombinov, V.
A1 - Vogel, Christian
A1 - Willbold, S.
A1 - Levandowski, G. V.
A1 - Meiller, M.
A1 - Müller, F.
A1 - Zang, J. W.
A1 - da Fonseca-Zang, W. A.
A1 - Jablonowski, N. D.
A1 - Schrey, S. D.
A1 - Adam, Christian
T1 - Soybean Fertilized by P-Phases from Bagasse-Based Materials: P-Extraction Procedures, Diffusive Gradients in Thin Films (DGT), and X-ray Diffraction Analysis (XRD)
N2 - The Brazilian sugarcane industry produced around 173 million tons (Mt) of bagasse in 2018. Bagasse is a by-product of juice extraction for ethanol and sugar production and is combusted in order to generate power, producing up to 10 Mt of ash per year. This ash contains various concentrations of plant nutrients, which allow the ash to be used as a crop fertilizer. However, the concentration and extractability of phosphorus (P), an essential plant nutrient, are low in bagasse ash. To increase the P content, we co-gasified and co-combusted bagasse with P-rich chicken manure. The resulting ash was thermochemically post-treated with alkali additives (Na2SO4 and K2SO4) to increase the availability of P to plants. We aimed to: (i) investigate the effect of thermochemical post-treatment of co-gasification residue and co-combustion ash on P availability to soybeans, (ii) explore the potential of chemical extraction methods (citric acid, neutral ammonium citrate, formic acid, and Mehlich-I) and diffusive gradients in thin films (DGT) to predict the availability of P to soybeans, and (iii) identify the responsible P-phases using X-ray diffraction . We evaluated P availability to soybeans growing in Brazilian Oxisol soil in two independent greenhouse pot experiments. The positive effect of thermochemical treatment on P availability from gasification residue was confirmed through the observation of increased P uptake and biomass in soybean plants. These findings were confirmed by chemical extraction methods and DGT. The gasification residue contained whitlockite as its main P-bearing phase. Thermochemical post-treatment converted whitlockite into highly soluble CaNaPO4. In contrast, co-combustion ash already contained highly soluble Ca(Na,K)PO4 as its main P-bearing phase, making thermochemical post-treatment unnecessary for increasing P availability. In conclusion, increased extractability and availability of P for soybeans were closely connected to the formation of calcium alkali phosphate. Our findings indicate that this combined methodology allows for the prediction of P-fertilization effects of ash.
KW - Sugar cane bagasse
KW - Chicken manure ash
KW - Thermochemical treatment
KW - Nutrient
KW - Plant availability
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509735
DO - https://doi.org/10.3390/agronomy10060895
VL - 10
SP - 895
EP - 6
PB - MDPI
AN - OPUS4-50973
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Balzer, R.
A1 - Behrens, H.
A1 - Waurischk, Tina
A1 - Reinsch, Stefan
A1 - Müller, Ralf
A1 - Kiefer, P.
A1 - Deubener, J.
A1 - Fechtelkord, M.
T1 - Water in Alkali Aluminosilicate Glasses
N2 - To understand the influence of water and alkalis on aluminosilicate glasses, three polymerized glasses with varying ratios of Na/K were synthesized [(22. 5-x)Na2O-xK2O-22.5 Al2O3-55 SiO2 with x = 0, 7.5, and 11.25]. Subsequently, these glasses were hydrated (up to 8 wt% H2O) in an internally heated gas pressure vessel. The density of hydrous glasses linearly decreased with water content above 1 wt%, consistent with the partial molar volume of H2O of 12 cm3/mol. Near-infrared spectroscopy revealed that hydroxyl groups are the dominant species at water content of <4 wt%, and molecular water becomes dominating at water content of >5 wt%. The fraction of OH is particularly high in the pure Na-bearing glass compared to the mixed alkali glasses. 27Al magic angle spinning-NMR spectroscopy shows that aluminum is exclusively fourfold coordinated with some variations in the local geometry. It appears that the local structure around Al becomes more ordered with increasing K/Na ratio. The incorporation of H2O reinforces this effect. The differential thermal analysis of hydrous glasses shows a significant mass loss in the range of glass transition already during the first upscan, implying the high mobility of water in the glasses. This observation can be explained by the open structure of the aluminosilicate network and by the low dissociation enthalpy of H2O in the glasses (≈ 8 kJ/mol). The effect of the dissolved H2O on the glass transition temperature is less pronounced than for other aluminosilicate glasses, probably because of the large fraction of Al in the glasses.
KW - NMR spectroscopy
KW - Alkali aluminosilicate glasses
KW - Water speciation
KW - Glass transition
KW - Infrared spectroscopy
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509497
DO - https://doi.org/10.3389/fmats.2020.00085
VL - 7
SP - 85
AN - OPUS4-50949
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Waurischk, Tina
A1 - Müller, Ralf
A1 - Reinsch, Stefan
A1 - Kiefer, P.
A1 - Deubener, J.
A1 - Balzer, R.
A1 - Behrens, H.
T1 - Crack Growth in Hydrous Soda-Lime Silicate Glass
N2 - Stable crack growth was measured for nominal dry and water-bearing (6 wt%) soda-lime silicate glasses in double cantilever beam geometry and combined with DMA studies on the effects of dissolved water on internal friction and glass transition, respectively. In vacuum, a decreased slope of logarithmic crack growth velocity versus stress intensity factor is evident for the hydrous glass in line with an increase of b-relaxation intensity indicating more energy Dissipation during fracture. Further, inert crack growth in hydrous glass is found to be divided into sections of different slope, which indicates different water related crack propagation mechanism. In ambient air, a largely extended region II is observed for the hydrous glass, which indicates that crack growth is more sensitive to ambient water.
KW - Internal friction
KW - Soda-lime silicate glass
KW - Water content
KW - Stable crack growth
KW - DCB geometry
KW - Stress intensity factor
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506829
DO - https://doi.org/10.3389/fmats.2020.00066
VL - 7
SP - Articel 66
AN - OPUS4-50682
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Laquai, René
A1 - Müller, Bernd R.
A1 - Schneider, J.
A1 - Kupsch, Andreas
A1 - Bruno, Giovanni
T1 - Using SXRR to Probe the Nature of Discontinuities in SLM Additive Manufactured Inconel 718 Specimens
N2 - The utilization of additive manufacturing (AM) to fabricate robust structural components relies on understanding the nature of internal anomalies or discontinuities, which can compromise the structural integrity. While some discontinuities in AM microstructures stem from similar mechanisms as observed in more traditional processes such as casting, others are unique to the AM process. Discontinuities in AM are challenging to detect, due to their submicron size and orientation dependency. Toward the goal of improving structural integrity, minimizing discontinuities in an AM build requires an understanding of the mechanisms of formation to mitigate their occurrence. This study utilizes various techniques to evaluate the shape, size, nature and distribution of discontinuities in AM Inconel 718, in a non-hot isostatic pressed (HIPed) as-built, non-HIPed and direct age, and HIPed with two step age samples. Non-destructive synchrotron radiation refraction and transmission radiography (SXRR) provides additional information beyond that obtained with destructive optical microscopy. SXRR was able to distinguish between voids, cracks and lack of melt in, due to its sensitivity to the orientation of the discontinuity.
KW - Additive manufacturing
KW - X-ray refraction radiography
KW - INCONEL 718
KW - Selective laser melting
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509836
DO - https://doi.org/10.1007/s11661-020-05847-5
SN - 1543-1940
VL - 51
IS - 8
SP - 4146
EP - 4157
PB - Springer
AN - OPUS4-50983
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Biesen, L.
A1 - Nirmalananthan-Budau, Nithiya
A1 - Hoffmann, Katrin
A1 - Resch-Genger, Ute
A1 - Müller, T. J. J.
T1 - Solid-State Emissive Aroyl-S,N-Ketene Acetals with Tunable
N2 - N-Benzyl aroyl-S,N-ketene acetals can be readily synthesized by condensation of aroyl chlorides and N-Benzyl 2-methyl benzothiazolium salts in good to excellent yields, yielding a library of 35 chromophores with bright solid-state emission and aggregation-induced emission characteristics.
Varying the substituent from electron-donating to electronwithdrawing enables the tuning of the solid-state emission Color from deep blue to red.
KW - Nano
KW - Nanoparticle
KW - Photoluminescence
KW - Fluorescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - dye
KW - Enhancement
KW - Particle
KW - Polarity
KW - AIE
KW - Aggregation
KW - Aggregation-induced emission
KW - Solid state emission
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509072
DO - https://doi.org/10.1002/anie.201916396
VL - 59
IS - 25
SP - 10037
EP - 10041
PB - Wiley Online Libary
AN - OPUS4-50907
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Meyerhofer, F.
A1 - Dissinger, F.
A1 - Weigert, Florian
A1 - Jungclaus, J.
A1 - Müller-Caspary, K.
A1 - Waldvogel, S. R.
A1 - Resch-Genger, Ute
A1 - Voss, T.
T1 - Citric Acid Based Carbon Dots with Amine Type Stabilizers: pHSpecific
N2 - We report the synthesis and spectroscopic characteristics of two different sets of carbon dots (CDs) formed by hydrothermal reaction between citric acid and polyethylenimine (PEI) or 2,3-diaminopyridine (DAP). Although the formation of amide-based species and the presence of citrazinic acid type derivates assumed to be responsible for a blue emission is confirmed for both CDs by elemental analysis, infrared spectroscopy, and mass spectrometry, a higher abundance of sp2-hybridized nitrogen is observed for DAP-based CDs, which causes a red-shift of the n-π* absorption band relative to the one of PEI-based CDs. These CD Systems possess high photoluminescence quantum yields (QY) of ∼40% and ∼48% at neutral pH, demonstrating a possible tuning of the optical properties by the amine precursor. pH-Dependent spectroscopic studies revealed a drop in QY to < 9% (pH ∼ 1) and < 21% (pH ∼ 12) for both types of CDs under acidic and basic conditions. In contrast, significant differences in the pHdependency of the n-π* transitions are found for both CD types which are ascribed to different (de)protonation sequences of the CD-specific fluorophores and functional groups using Zeta potential analysis.
KW - Fluorescence
KW - Particle
KW - Nano
KW - Surface group analysis
KW - Carbon dot
KW - C-dot
KW - Fluorescent probe
KW - Quantum yield
KW - Synthesis
KW - IR
KW - MS
KW - Polymer
KW - Ligand
PY - 2020
DO - https://doi.org/10.1021/acs.jpcc.9b11732
VL - 124
IS - 16
SP - 8894
EP - 8904
PB - American Chemical Society
AN - OPUS4-50813
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cant, D. J. H.
A1 - Minelli, C.
A1 - Sparnacci, K.
A1 - Müller, Anja
A1 - Kalbe, H.
A1 - Stoger-Pollach, M.
A1 - Unger, Wolfgang
A1 - Werner, W. S. M.
A1 - Shard, A. G.
T1 - Surface-Energy Control and Characterization of Nanoparticle Coatings
N2 - Accurate and reproducible measurement of the structure and properties of high-value nanoparticles is extremely important for their commercialization. A significant proportion of engineered nanoparticle systems consist of some form of nominally core-shell structure, whether by design or unintentionally. Often, these do not form an ideal core-shell structure, with typical deviations including polydispersity of the core or shell, uneven or incomplete shells, noncentral cores, and others. Such systems may be created with or without intent, and in either case an understanding of the conditions for formation of such particles is desirable. Precise determination of the structure, composition, size, and shell thickness of such particles can prove challenging without the use of a suitable range of characterization techniques. Here, the authors present two such polymer core-shell nanoparticle systems, consisting of polytetrafluoroethylene cores coated with a range of thicknesses of either polymethylmethacrylate or polystyrene. By consideration of surface energy, it is shown that these particles are expected to possess distinctly differing coating structures, with the polystyrene coating being incomplete. A comprehensive characterization of these systems is demonstrated, using a selection of complementary techniques including scanning electron microscopy, scanning transmission electron microscopy, thermogravimetric analysis, dynamic light scattering, differential centrifugal sedimentation, and X-ray photoelectron spectroscopy. By combining the results provided by these techniques, it is possible to achieve superior characterization and understanding of the particle structure than could be obtained by considering results separately.
KW - Nanoparticles
KW - Core-shell
KW - XPS
KW - Size
KW - Thickness
KW - Damage
PY - 2020
DO - https://doi.org/10.1021/acs.jpcc.0c02161
VL - 124
IS - 20
SP - 11200
EP - 11211
PB - ACS
CY - Washington DC
AN - OPUS4-50899
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kirilina, E.
A1 - Helbling, S.
A1 - Morawski, M.
A1 - Pine, K.
A1 - Reimann, K.
A1 - Jankuhn, S.
A1 - Dinse, J.
A1 - Deistung, A.
A1 - Reichenbach, J. R.
A1 - Trampel, R.
A1 - Geyer, S.
A1 - Müller, Larissa
A1 - Jakubowski, Norbert
A1 - Arendt, T.
A1 - Bazin, P.-L.
A1 - Weiskopf, N.
T1 - Superficial white matter imaging: Contrast mechanisms and whole-brain in vivo mapping
N2 - Superficial white matter (SWM) contains the most cortico-cortical white matter connections in the human brain encompassing the short U-shaped association fibers. Despite its importance for brain connectivity, very little is known about SWM in humans, mainly due to the lack of noninvasive imaging methods. Here, we lay the groundwork for systematic in vivo SWM mapping using ultrahigh resolution 7 T magnetic resonance imaging. Using biophysical modeling informed by quantitative ion beam microscopy on postmortem brain tissue, we demonstrate that MR contrast in SWM is driven by iron and can be linked to the microscopic iron distribution. Higher SWM iron concentrations were observed in U-fiber–rich frontal, temporal, and parietal areas, potentially reflecting high fiber density or late myelination in these areas. Our SWM mapping approach provides the foundation for systematic studies of interindividual differences, plasticity, and pathologies of this crucial structure for cortico-cortical connectivity in humans.
KW - Magnetic resonance imaging
KW - Laser ablation
KW - ICP-MS
KW - Brain
KW - Imaging
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514430
DO - https://doi.org/10.1126/sciadv.aaz9281
SN - 2375-2548
VL - 6
IS - 41
SP - eaaz9281
PB - American Association for the Advancement of Science (Science/AAAS)
CY - Washington, DC, USA
AN - OPUS4-51443
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Baer, D. R.
A1 - Cant, D. J. H.
A1 - Castner, D. G.
A1 - Ceccone, G.
A1 - Engelhard, M. H.
A1 - Karakoti, A. S.
A1 - Müller, Anja
ED - Hodoroaba, Vasile-Dan
ED - Unger, Wolfgang
ED - Shard, A. G.
T1 - Preparation of nanoparticles for surface analysis
N2 - A variety of methods used to prepare nano-objects for surface analysis are described along with information about when they might be best applied. Intrinsic properties of NPs which complicate their characterization and need to be considered when planning for surface or other analyses of NPs are identified, including challenges associated with reproducible synthesis and functionalization of the particles as well as their dynamic nature. The relevant information about the sample preparation processes, along with analysis details and data that need to be added to the collection of material provenance information is identified. Examples of protocols that have been successfully used for preparation of nano-objects for surface analysis are included in an annex.
KW - Sample preparation
KW - Nanoparticles
KW - Surface chemistry
KW - XPS
KW - Dynamic behavior
KW - Nano-object
KW - Surface analysis
PY - 2020
SN - 978-0-12-814182-3
DO - https://doi.org/10.1016/B978-0-12-814182-3.00018-3
SP - 295
EP - 347
PB - Elsevier
CY - Amsterdam
AN - OPUS4-50186
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kunz, C.
A1 - Bonse, Jörn
A1 - Spaltmann, Dirk
A1 - Neumann, C.
A1 - Turchanin, A.
A1 - Bartolomé, J. F.
A1 - Müller, F. A.
A1 - Gräf, S.
T1 - Tribological performance of metal-reinforced ceramic composites selectively structured with femtosecond laser-induced periodic surface structures
N2 - The impact of femtosecond (fs) laser-induced periodic surface structures (LIPSS) on tribological properties was investigated for metal-reinforced ceramic composites (Al2O3-ZrO2-Nb). For this purpose, the metallic niobium (Nb) phase was selectively structured with LIPSS in an air environment with different values of the fs-laser peak fluence by near-infrared fs-laser radiation (λ = 1025 nm, τ = 300 fs, frep = 1 kHz), taking advantage of the different light absorption behavior of ceramic and metal. The tribological performance was evaluated by reciprocating sliding tests in a ball-on-disc configuration using Ringer's solution as lubricant. The surfaces were characterized before and after laser irradiation by optical microscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and by measuring the contact angle with Ringer's solution. The LIPSS formation resulted in an increased wetting of the surface with the lubricant. Moreover, the selectively structured composite surfaces revealed a coefficient of friction significantly reduced by a factor of ~3 when compared to the non-irradiated surface. Furthermore, the formation of a laser-induced oxidation layer was detected with NbO as the most prominent oxidation state. Selectively structured composites with outstanding mechanical properties and enhanced tribological performance are of particular interest for biomedical applications.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Femtosecond laser ablation
KW - Ceramic matrix composites
KW - Tribology
PY - 2020
DO - https://doi.org/10.1016/j.apsusc.2019.143917
SN - 0169-4332
SN - 1873-5584
VL - 499
IS - 1
SP - 143917
PB - Elsevier B.V.
CY - Amsterdam
AN - OPUS4-49255
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Laquai, René
A1 - Müller, Bernd R.
A1 - Kasperovich, G.
A1 - Requena, G.
A1 - Haubrich, J.
A1 - Bruno, Giovanni
T1 - Classification of defect types in SLM Ti-6Al-V4 by X-ray refraction topography
N2 - Porosity in additively manufactured materials, such as laser powder bed fusion Ti-Al6-V4, can play an important role in their mechanical performance. Not only the total porosity but also the shape/morphology of the individual pores need to be considered. Therefore, it is necessary to determine the distributions of different defect types (especially fusing defects and keyhole pores) and their dependence on process parameters. We show that synchrotron X-ray refraction radiography allows analysis of large samples (up to several millimeters) without compromising the detectability of submicrometer defects. Correspondingly, a classification tool is introduced that is able to quantitatively distinguish defects such as keyhole pores and binding defects with a confidence level of 94 %, even when the shape cannot be discerned because of limited spatial resolution.
KW - Additive manufacturing
KW - Selective laser melting
KW - X-ray refraction
KW - Microscopy
KW - Porosity
KW - X-ray computed tomography
KW - BAMline
KW - Synchrotron Radiation
PY - 2020
DO - https://doi.org/10.1520/MPC20190080
SN - 2379-1365
VL - 9
IS - 1
SP - 82
EP - 93
PB - ASTM International
CY - West Conshohocken, PA
AN - OPUS4-50470
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Herrmann, Ralf
A1 - Hille, Falk
A1 - Said, Samir
A1 - Sterthaus, Jens
A1 - Müller, Karsten
A1 - Quercetti, Thomas
A1 - Wille, Frank
A1 - Paffenholz, J.-A.
A1 - Baeßler, Matthias
ED - Papadrakakis, M.
ED - Fragiadakis, M.
ED - Papadimitriou, C.
T1 - Implementing a Structural Health Monitoring system using digital models of the BAM large drop test facility in Horstwalde
N2 - At the Bundesanstalt für Materialforschung und -prüfung (BAM) full scale specimens for nuclear transport and storage containers (casks) are tested for their structural integrity in a series of drop tests on the Test Site Technical Safety in Horstwalde, 50 km south of Berlin. These drop tests cause a major stress not only on the casks, but also on the steel tower structure of the test facility, itself. The load pattern makes the structure very interesting for detailed investigation. The focus of the monitoring lies on the bolted joints of the flange connections that are a typical connection for cylindrical elements if welding is technical or economical unfavorable. The definition of the monitoring takes was done by investigating the existing documents and inspection results accompanied by building an initial digital representation of the structure, consisting of two finite element (FE) models and a geometrical 3D point cloud representation. As a first step the structures behavior during static and dynamic loading was analyzed using measurement data and an updated numerical FE Model. The idea behind is to use models for a digital planning and operation/evaluation of the structural health monitoring. A static FE simulation and a dynamic FE simulation are generated, to investigate how the structure behaves under the load conditions.
T2 - XI International Conference on Structural Dynamics (EuroDyn 2020)
CY - Online meeting
DA - 23.11.2020
KW - Structural Health Monitoring
KW - Drop Tests
KW - System Identification
KW - Digital Models
KW - BIM
PY - 2020
UR - https://generalconferencefiles.s3-eu-west-1.amazonaws.com/eurodyn_2020_ebook_procedings_vol1.pdf
SN - 978-618-85072-0-3
VL - 1
SP - 1293
EP - 1304
PB - Institute of Structural Analysis and Antiseismic Research
CY - Athen
AN - OPUS4-51592
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Welter, T.
A1 - Müller, Ralf
A1 - Deubener, J.
A1 - Marzok, Ulrich
A1 - Reinsch, Stefan
T1 - Hydrogen Permeation Through Glass
N2 - Physical storage of gaseous hydrogen under high-pressure in glassy micro-containers such as spheres and capillaries is a promising concept for enhancing safety and the volumetric capacity of mobile hydrogen storage systems. As very low permeation through the container wall is required for storage of compressed hydrogen, development of glasses of minimal hydrogen permeability is needed. For this purpose, one has to understand better the dependence of hydrogen permeability on glass structure. The paper points out that minimizing the accessible free volume is as one strategy to minimize hydrogen permeability. Based on previously measured and comprehensive literature data, it is shown that permeation is independently controlled by ionic porosity and network modifier content. Thus, ionic porosity in modified and fully polymerized networks can be decreased equally to the lowest hydrogen permeability among the glasses under study. Applying this concept, a drop of up to 30,000 with respect to the permeation of hydrogen molecules through silica glass is attainable.
KW - Ionic porosity
KW - hydrogen storage
KW - Glass
KW - Permeability
KW - Solubility
KW - Diffusivity
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513927
DO - https://doi.org/10.3389/fmats.2019.00342
VL - 6
SP - Article 342
AN - OPUS4-51392
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Liens, A.
A1 - Reveron, H.
A1 - Douillard, T.
A1 - Blanchard, N.
A1 - Lughi, V.
A1 - Sergo, V.
A1 - Laquai, René
A1 - Müller, Bernd R.
A1 - Bruno, Giovanni
A1 - Schomer, S.
A1 - Fürderer, T.
A1 - Adolfsson, E.
A1 - Courtois, N.
A1 - Swain, M.
A1 - Chevalier, J.
T1 - Phase transformation induces plasticity with negligible damage in ceria-stabilized zirconia-based ceramics
N2 - Ceramics and their composites are in general brittle materials because they are predominantly made up of ionic and covalent bonds that avoid dislocation motion at room temperature. However, a remarkable ductile behavior has been observed on newly developed 11 mol.% ceria-stabilized zirconia (11Ce-TZP) composite containing fine alumina (8 vol.% Al2O3) and elongated strontium hexa-aluminate (8 vol.% SrAl12O19) grains. The as-synthesized composite also has shown full resistance to Low Temperature Degradation (LTD), relatively high strength and exceptionally high Weibull modulus, allowing its use in a broader range of biomedical applications. In this study, to deepen the understanding of plastic deformation in Ce-TZP based composites that could soon be used for manufacturing dental implants, different mechanical tests were applied on the material, followed by complete microstructural characterization. Distinct from pure Ce-TZP material or other zirconia-based ceramics developed in the past, the material here studied can be permanently strained without affecting the Young modulus, indicating that the ductile response of tested samples cannot be associated to damage occurrence. This ductility is related to the stress-induced tetragonal to monoclinic (t-m) zirconia phase transformation, analogue to Transformation-Induced Plasticity (TRIP) steels, where retained austenite is transformed to martensite. The aim of this study is to corroborate if the observed plasticity can be associated exclusively to the zirconia t-m phase transformation, or also to microcraking induced by the transformation. The t-m transformed-zones produced after bending and biaxial tests were examined by X-ray refraction and SEM/TEM coupled with Raman. The results revealed that the observed elastic-plastic behavior occurs without extensive microcracking, confirming a purely elastic-plastic behavior driven by the phase transformation (absence of damage).
KW - Zirconia
KW - Ceria
KW - Ceramic matrix composite
KW - Plasticity
KW - Phase transformation
KW - X-Ray Refraction
PY - 2020
UR - http://www.sciencedirect.com/science/article/pii/S1359645419307177
DO - https://doi.org/10.1016/j.actamat.2019.10.046
SN - 1359-6454
VL - 183
SP - 261
EP - 273
PB - Elsevier Ltd.
AN - OPUS4-49740
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bennet, Francesca
A1 - Müller, Anja
A1 - Radnik, Jörg
A1 - Hachenberger, Y.
A1 - Jungnickel, H.
A1 - Laue, P.
A1 - Luch, A.
A1 - Tentschert, J.
T1 - Preparation of Nanoparticles for ToF-SIMS and XPS Analysis
N2 - Nanoparticles have gained increasing attention in recent years due to their potential and application in different fields including medicine, cosmetics, chemistry, and their potential to enable advanced materials. To effectively understand and regulate the physico-chemical properties and potential adverse effects of nanoparticles, validated measurement procedures for the various properties of nanoparticles need to be developed. While procedures for measuring nanoparticle size and size Distribution are already established, standardized methods for analysis of their surface chemistry are not yet in place, although the influence of the surface chemistry on nanoparticle properties is undisputed. In particular, storage and preparation of nanoparticles for surface analysis strongly influences the analytical results from various methods, and in order to obtain consistent results, sample preparation must be both optimized and standardized. In this contribution, we present, in detail, some standard procedures for preparing nanoparticles for surface analytics. In principle, nanoparticles can be deposited on a suitable substrate from suspension or as a powder. Silicon (Si) Wafers are commonly used as substrate, however, their cleaning is critical to the process. For sample preparation from suspension, we will discuss drop-casting and spin-coating, where not only the cleanliness of the substrate and purity of the suspension but also its concentration play important roles for the success of the preparation methodology.
For nanoparticles with sensitive ligand shells or coatings, deposition as powders is more suitable, although this method requires particular care in fixing the sample.
KW - Titania nanoparticles
KW - X-ray photoelectron spectroscopy
KW - Secondary ion mass spectrometry
KW - Surface chemisttry
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520103
UR - https://www.jove.com/video/61758
DO - https://doi.org/10.3791/61758
VL - 163
SP - e61758
AN - OPUS4-52010
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Biesen, L.
A1 - May, L.
A1 - Nirmalananthan-Budau, Nithiya
A1 - Hoffmann, Katrin
A1 - Resch-Genger, Ute
A1 - Müller, T. J. J.
T1 - Communication of Bichromophore Emission upon Aggregation – Aroyl-S,N-ketene Acetals as Multifunctional Sensor Merocyanines
N2 - Aroyl-S,N-ketene acetal-based bichromophores can be readily synthesized in a consecutive three-component synthesis in good to excellent yields by condensation of aroyl chlorides and an N-(p-bromobenzyl) 2-methyl benzothiazolium salt followed by a Suzuki coupling, yielding a library of 31 bichromophoric fluorophores with substitution patterntunable emission properties. Varying both chromophores enables different communication pathways between the chromophores, exploiting aggregation-induced emission (AIE) and energy transfer (ET) properties, and thus, furnishing aggregation-based fluorescence switches. Possible applications range from fluorometric analysis of alcoholic beverages to pH sensors.
KW - Dye
KW - Fluorescence
KW - Aggregation induced emission
KW - Signal enhancement
KW - Energy transfer
KW - Switch
KW - Sensor
KW - Quantum yield
KW - Lifetime
KW - Photophysics
KW - Synthesis
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531123
DO - https://doi.org/10.1002/chem.202102052
VL - 27
IS - 53
SP - 13426
EP - 13434
PB - Wiley-VCH
AN - OPUS4-53112
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cant, D. J. H.
A1 - Müller, Anja
A1 - Clifford, C. A.
A1 - Unger, Wolfgang
A1 - Shard, A. G.
T1 - Summary of ISO/TC 201 Technical Report 23173—Surface chemical analysis—Electron spectroscopies—Measurement of the thickness and composition of nanoparticle coatings
N2 - ISO Technical Report 23173 describes methods by which electron spectroscopies, including X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and synchrotron techniques, can be employed to calculate the Coating thicknesses and compositions of nanoparticles. The document has been developed to review and outline the current state-of-the-art for such measurements. Such analyses of core–shell nanoparticles are common within the literature, however the
methods employed are varied; the relative advantages and disadvantages of These methods, and the optimal usage of each may not be clear to the general analyst. ISO Technical Report 23173 aims to clarify the methods that are available, describe them in clear terms, exhibit examples of their use, and highlight potential issues users may face. The information provided should allow analysts of electron spectroscopy data to make clear choices regarding the appropriate analysis of electron spectroscopy data from coated nanoparticle systems and provide a basis for understanding and comparing results from different methods and systems.
KW - Electron spectroscopy
KW - Core-shell
KW - Nanoparticles
KW - ISO 23173
KW - XPS
KW - Thickness
KW - Composition
PY - 2021
DO - https://doi.org/10.1002/sia.6987
SN - 0142-2421
VL - 53
IS - 10
SP - 893
EP - 899
PB - John Wiley & Sons Ltd
AN - OPUS4-52976
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kupsch, Andreas
A1 - Laquai, René
A1 - Müller, Bernd R.
A1 - Paciornik, S.
A1 - Horvath, J.
A1 - Tushtev, K.
A1 - Rezwan, K.
A1 - Bruno, Giovanni
T1 - Evolution of Damage in All-Oxide Ceramic Matrix Composite After Cyclic Loading
N2 - While structural ceramics usually display a brittle mechanical behavior, their composites may show nonlinearities, mostly due to microcracking. Herein, the stiffness evolution of a sandwich-like laminate of an Al2O3 15%vol. ZrO2 matrix reinforced with Nextel 610 fibers is studied as a function of number of cycles N in tension. The stiffness of the composite degrades with increasing N, indicating microcracking. However, synchrotron X-ray refraction radiography shows that the internal specific surface of such cracks varies differently. A modeling strategy is developed for the calculation of the equivalent stiffness of mixtures (first the matrix and then the sandwich), based on the Voigt and Reuß schemes. The Bruno–Kachanov model is then used to estimate the initial microcrack density in the matrix (due to the thermal expansion mismatch) and the amount of microcracking increase upon cyclic loading. The stiffness in the composite degrades dramatically already after 20 000 cycles but then remains nearly constant. The combination of mechanical testing, quantitative imaging analysis, and modeling provides insights into the damage mechanisms acting: microcrack propagation is more active than microcrack initiation upon cyclic loading, but the second also occurs. This scenario is similar but not equal to previous results on porous and microcracked ceramics.
KW - Ceramic matrix composites
KW - Homogenization schemes
KW - Microcracking
KW - Nonlinear behavior
KW - Synchrotron X-ray refraction radiography
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534541
DO - https://doi.org/10.1002/adem.202100763
SN - 1527-2648
SN - 1438-1656
VL - 24
IS - 6
SP - 2100763 -1
EP - 2100763 -13
PB - VCH GmbH
CY - Weinheim
AN - OPUS4-53454
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wipfler, B.
A1 - Bradler, S.
A1 - Büsse, S.
A1 - Hammel, J.
A1 - Müller, Bernd R.
A1 - Pass, G.
T1 - Evolutionary morphology of the antennal heart in stick and leaf insects (Phasmatodea) and webspinners (Embioptera) (Insecta: Eukinolabia)
N2 - The morphology of the antennal hearts in the head of Phasmatodea and Embioptera was investigated with particular reference to phylogenetically relevant key taxa. The antennal circulatory organs of all examined species have the same basic construction: they consist of antennal vessels that are connected to ampullae located in the head near the antenna base. The ampullae are pulsatile due to associated muscles, but the points of attachment differ between the species studied. All examined Phasmatodea species have a Musculus (M.) interampullaris which extends between the two ampullae plus a M. ampulloaorticus that runs from the ampullae to the anterior end of the aorta; upon contraction, all these muscles dilate the lumina of both ampullae at the same time. In Embioptera, only the australembiid Metoligotoma has an M. interampullaris. All other studied webspinners instead have a M. ampullofrontalis which extends between the ampullae and the frontal region of the head capsule; these species do not have M. ampulloaorticus. Outgroup comparison indicates that an antennal heart with a M. interampullaris is the plesiomorphic character state among Embioptera and the likely ground pattern of the taxon Eukinolabia. Antennal hearts with a M. ampullofrontalis represent a derived condition that occurs among insects only in some embiopterans. These findings help to further clarify the controversially discussed internal phylogeny of webspinners by supporting the view that Australembiidae are the sister group of the remaining Embioptera.
KW - Phylogeny
KW - Polyneoptera
KW - Metoligotoma
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527795
DO - https://doi.org/10.1007/s00435-021-00526-4
SN - 1432-234X
VL - 140
IS - 3
SP - 331
EP - 340
PB - Springer
AN - OPUS4-52779
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Jaeger, Carsten
A1 - Ritter, D.
A1 - Goeritzer, M.
A1 - Thiele, A.
A1 - Blumrich, A.
A1 - Beyhoff, N.
A1 - Luettges, K.
A1 - Smeir, E.
A1 - Kasch, J.
A1 - Grune, J.
A1 - Müller, O.
A1 - Klopfleisch, R.
A1 - Foryst-Ludwig, A.
A1 - Kintscher, U.
T1 - Liver X Receptor Agonist AZ876 Induces Beneficial Endogenous Cardiac Lipid Reprogramming and Protects Against Isoproterenol-Induced Cardiac Damage
N2 - Background - It is known that dietary intake of polyunsaturated fatty acids may improve cardiac function. However, relatively high daily doses are required to achieve sufficient cardiac concentrations of beneficial omega‐3 fatty acids. The liver X receptor (LXR) is a nuclear hormone receptor and a crucial regulator of lipid homeostasis in mammals. LXR activation has been shown to endogenously reprogram cellular lipid profiles toward increased polyunsaturated fatty acids levels. Here we studied whether LXR lipid reprogramming occurs in cardiac tissue and exerts cardioprotective actions.
Methods and Results - Male 129SV mice were treated with the LXR agonist AZ876 (20 µmol/kg per day) for 11 days. From day 6, the mice were injected with the nonselective β‐agonist isoproterenol for 4 consecutive days to induce diastolic dysfunction and subendocardial fibrosis while maintaining systolic function. Treatment with isoproterenol led to a marked impairment of global longitudinal strain and the E/e' ratio of transmitral flow to mitral annular velocity, which were both significantly improved by the LXR agonist. Histological examination showed a significant reduction in isoproterenol‐induced subendocardial fibrosis by AZ876. Analysis of the cardiac lipid composition by liquid chromatography‐high resolution mass spectrometry revealed a significant increase in cardiac polyunsaturated fatty acids levels and a significant reduction in saturated fatty acids by AZ876.
Conclusions - The present study provides evidence that the LXR agonist AZ876 prevents subendocardial damage, improves global longitudinal strain and E/e' in a mouse model of isoproterenol‐induced cardiac damage, accompanied by an upregulation of cardiac polyunsaturated fatty acids levels. Cardiac LXR activation and beneficial endogenous cardiac lipid reprogramming may provide a new therapeutic strategy in cardiac disease with diastolic dysfunction.
KW - Heart failure
KW - Lipids
KW - Liver X receptor
KW - Diastolic dysfunction
KW - Nuclear receptor
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529352
DO - https://doi.org/10.1161/JAHA.120.019473
VL - 10
IS - 14
SP - e019473
AN - OPUS4-52935
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Waurischk, Tina
A1 - Reinsch, Stefan
A1 - Rouxel, T.
A1 - Behrens, H.
A1 - Deubener, J.
A1 - Müller, Ralf
T1 - Vacuum crack growth in alkali silicate glasses
N2 - Crack growth velocity in alkali silicate glasses was measured in vacuum across 10 orders of magnitude with double cantilever beam technique. Measured and literature crack growth data were compared with calculated intrinsic fracture toughness data obtained from Young´s moduli and the theoretical fracture surface energy estimated from chemical bond energies. Data analysis reveals significant deviations from this intrinsic brittle fracture behavior. These deviations do not follow simple compositional trends. Two opposing processes may explain this finding: a decrease in the apparent fracture surface energy due to stress-induced chemical changes at the crack tip and its increase due to energy dissipation during fracture.
KW - Silicate glass
KW - Brittle fracture
KW - Crack growth
KW - Calculated intrinsic fracture toughness
PY - 2021
DO - https://doi.org/10.1016/j.jnoncrysol.2021.121094
SN - 0022-3093
VL - 572
SP - 1
EP - 8
PB - Elsevier
CY - Amsterdam
AN - OPUS4-53144
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tschöke, K.
A1 - Müller, I.
A1 - Memmolo, V.
A1 - Moix-Bonet, M.
A1 - Moll, J.
A1 - Lugovtsova, Yevgeniya
A1 - Golub, M.
A1 - Sridaran Venkat, R.
A1 - Schubert, L.
T1 - Feasibility of Model-Assisted Probability of Detection Principles for Structural Health Monitoring Systems based on Guided Waves for Fibre-Reinforced Composites
N2 - In many industrial sectors, Structural Health Monitoring (SHM) is considered as an addition to Non-Destructive Testing (NDT) that can reduce maintenance effort during lifetime of a technical facility, structural component or vehicle. A large number of SHM methods is based on ultrasonic waves, whose properties change depending on structural health. However, the wide application of SHM systems is limited due to the lack of suitable methods to assess their reliability. The evaluation of the system performance usually refers to the determination of the Probability of Detection (POD) of a test procedure. Up to now, only few limited methods exist to evaluate the POD of SHM systems, which prevent them from being standardised and widely accepted in industry. The biggest hurdle concerning the POD calculation is the large amount of samples needed. A POD analysis requires data from numerous identical structures with integrated SHM systems. Each structure is then damaged at different locations and with various degrees of severity. All of this is connected to high costs. Therefore, one possible way to tackle this problem is to perform computer-aided investigations. In this work, the POD assessment procedure established in NDT according to the Berens model is adapted to guided wave-based SHM systems. The approach implemented here is based on solely computer-aided investigations. After efficient modelling of wave propagation phenomena across an automotive component made of a carbon fibre-reinforced composite, the POD curves are extracted. Finally, the novel concept of a POD map is introduced to look into the effect of damage position on system reliability.
KW - Reliability
KW - Acoustics
KW - Monitoring
KW - Automotive engineering
KW - Elastodynamic Finite Inegration Technique
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528218
DO - https://doi.org/10.1109/TUFFC.2021.3084898
VL - 68
IS - 10
SP - 3156
EP - 3173
AN - OPUS4-52821
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Ralf
A1 - Waurischk, Tina
A1 - Behrens, H.
A1 - Deubener, J.
T1 - Crack growth in borate and silicate glasses: Stress-corrosion susceptibility and hydrolytic resistance
N2 - A double cantilever beam technique in air equipped with ultrasound modulation was used to measure the crack velocity v in borate and silicate glasses. In all glasses v and the stress intensity KI followed the empirical correlation v ~ KIn. Indicated by its smallest KI at v = 1 μm s − 1, KI* = 0.27 MPa m0.5, the silicoborate glass containing 70 mol% B2O3 was found most susceptible to stress-corrosion enhanced crack growth. Contrarily, the sodium calcium magnesium silicate glass appeared least susceptible with KI* = 0.57 MPa m0.5. No clear correlation is evident between KI*, reflecting the stress-corrosion susceptibility, and the hydrolytic resistance for all glasses under study, but values of n obtained from the present study and taken from previous literature for 35 glasses tend to decrease with increasing network modifier ion fraction. Energy dissipation during stress-corrosion enhanced crack propagation is assumed to cause this trend.
KW - DCB
KW - Alkali and alkaline earth silicate and borate glass
KW - Crack growth in air
KW - Stress-corrosion
KW - Stress intensity
PY - 2021
DO - https://doi.org/10.1016/j.jnoncrysol.2020.120414
VL - 551
SP - 120414
PB - Elsevier B.V.
AN - OPUS4-51393
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Biesen, L.
A1 - Krenzer, J.
A1 - Nirmalananthan-Budau, Nithiya
A1 - Resch-Genger, Ute
A1 - Müller, Th. J. J.
T1 - Asymmetrically bridged aroyl-S,N-ketene acetalbased multichromophores with aggregationinduced tunable emission
N2 - Asymmetrically bridged aroyl-S,N-ketene acetals and aroyl-S,N-ketene acetal multichromophores can be readily synthesized in consecutive three-, four-, or five-component syntheses in good to excellent yields by several successive Suzuki-couplings of aroyl-S,N-ketene acetals and bis(boronic)acid esters. Different aroyl-S,N-ketene acetals as well as linker molecules yield a library of 23 multichromophores with substitution and linker pattern-tunable emission properties. This allows control of different communication pathways between the chromophores and of aggregation-induced emission (AIE) and energy transfer (ET) properties, providing elaborate aggregation-based fluorescence switches.
KW - Dye
KW - Aggregation
KW - Aggregation induced emission
KW - Signal enhancement
KW - Energy transfer
KW - Switch
KW - Sensor
KW - Quantum yield
KW - Lifetime
KW - Photophysics
KW - Sythesis
KW - Nanaoparticle
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550719
DO - https://doi.org/10.1039/d2sc00415a
VL - 13
SP - 5374
EP - 5381
PB - Royal Society of Chemistry
AN - OPUS4-55071
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tielemann, Christopher
A1 - Reinsch, Stefan
A1 - Maaß, Robert
A1 - Deubener, J.
A1 - Müller, Ralf
T1 - Internal nucleation tendency and crystal surface energy obtained from bond energies and crystal lattice data
N2 - We present an easy-to-apply method to predict structural trends in the internal nucleation tendency of oxide glasses. The approach is based on calculated crystal fracture surface energies derived from easily accessible diatomic bond energy and crystal lattice data. The applicability of the method is demonstrated on literature nucleation data for isochemically crystallizing oxide glasses.
KW - Glass
KW - Nucleation tendency
KW - Fracture surface energy
KW - Crystal lattice
KW - Bond energy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548814
DO - https://doi.org/10.1016/j.nocx.2022.100093
SN - 2590-1591
VL - 14
SP - 1
EP - 5
PB - Elsevier B.V.
AN - OPUS4-54881
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sieber, M. J.
A1 - Wilke, M.
A1 - Appelt, O.
A1 - Oelze, Marcus
A1 - Koch-Müller, M.
T1 - Melting relations of Ca–Mg carbonates and trace element signature of carbonate melts up to 9 GPa – A proxy for melting of carbonated mantle lithologies
N2 - The most profound consequences of the presence of Ca–Mg carbonates (CaCO3–MgCO3) in the Earth’s upper mantle may be to lower the melting temperatures of the mantle and control the melt composition.
Low-degree partial melting of a carbonate-bearing mantle produces CO2-rich, silica-poor melts compositionally imposed by the melting relations of carbonates. Thus, understanding the melting relations in the CaCO3–MgCO3 system facilitates the interpretation of natural carbonate-bearing silicate systems.
We report the melting relations of the CaCO3–MgCO3 system and the partition coefficient of trace elements between carbonates and carbonate melt from experiments at high pressure (6 and 9 GPa) and temperature (1300–1800 ◦C) using a rocking multi-anvil press. In the absence of water, Ca–Mg carbonates are stable along geothermal gradients typical of subducting slabs. Ca–Mg carbonates (∼ Mg0.1–0.9Ca0.9–0.1CO3) partially melt beneath mid-ocean ridges and in plume settings. Ca–Mg carbonates melt incongruently, forming periclase crystals and carbonate melt between 4 and 9 GPa. Furthermore, we show that the rare earth element (REE) signature of Group-I kimberlites, namely strong REE fractionation and depletion of heavy REE relative to the primitive mantle, is resembled by carbonate melt in equilibrium with Ca-bearing magnesite and periclase at 6 and 9 GPa. This suggests that the dolomite–magnesite join of the CaCO3–MgCO3 system might be useful to approximate the REE signature of carbonate-rich melts parental to kimberlites.
KW - High pressure experiments
KW - Laser Ablation
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561197
DO - https://doi.org/10.5194/ejm-34-411-2022
SN - 0935-1221
VL - 34
IS - 5
SP - 411
EP - 424
PB - Copernicus Publications
CY - Göttingen
AN - OPUS4-56119
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heuser, Lina
A1 - Nofz, Marianne
A1 - Müller, Ralf
A1 - Deubener, J.
T1 - Silver dissolution and precipitation in an Na2O–ZnO–B2O3 metallization paste glass
N2 - Thermally stimulated interactions between silver and glass, that is, silver dissolution as Ag+ and precipitation as Ag0 were studied in two glass series of molar target composition xAg2O–(19 − x)Na2O–28ZnO–53B2O3 with x = 0, 0.1, 0.5, 5 and (19Na2O–28ZnO–53B2O3)+yAg2O with y = 0.01, 0.05. These act as model for low-melting borate glasses being part of metallization pastes. The occurrence of metallic silver precipitates in melt-quenched glass ingots demonstrated that silver dissolved only in traces (< 0.01 mol%) in the glasses. The dissolved silver was detected by means of Raman spectroscopy and energy-dispersive X-ray spectroscopy. Increasing x in the batch could not lead to a significant increase of the silver ion fraction in the glass as possible in binary silver borate glasses. In situ observation of heated AgNO3 mixed with the base glass frit in a hot stage microscope showed that Ag0 precipitation occurs already at the solid state. At higher temperatures, small droplets of liquid silver were found to move freely within the melt, whereas coalescence caused a stepwise increase of their size.
These results contribute to the understanding of formation of silver precipitates in metallization pastes described in the literature.
KW - Silver metallization paste
KW - Batch reactions
KW - Borate
KW - Glass forming melts
KW - Glass manufacturing
KW - Raman spectroscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559433
DO - https://doi.org/10.1111/ijag.16613
SN - 2041-1286
SP - 1
EP - 11
PB - Wiley Online Library
AN - OPUS4-55943
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 - Dombinov, V.
A1 - Herzel, Hannes
A1 - Meiller, M.
A1 - Müller, F.
A1 - Willbold, S.
A1 - Zang, J. W.
A1 - da Fonseca-Zang, W. A.
A1 - Adam, Christian
A1 - Klose, H.
A1 - Poorter, H.
A1 - Jablonowski, N. D.
A1 - Schrey, S. D.
T1 - Sugarcane bagasse ash as fertilizer for soybeans: Effects of added residues on ash composition, mineralogy, phosphorus extractability and plant availability
N2 - Sugarcane bagasse is commonly combusted to generate energy. Unfortunately, recycling strategies rarely consider the resulting ash as a potential fertilizer. To evaluate this recycling strategy for a sustainable circular economy, we characterized bagasse ash as a fertilizer and measured the effects of co-gasification and co-combustion of bagasse with either chicken manure or sewage sludge: on the phosphorus (P) mass fraction, P-extractability, and mineral P phases. Furthermore, we investigated the ashes as fertilizer for soybeans under greenhouse conditions. All methods in combination are reliable indicators helping to assess and predict P availability from ashes to soybeans. The fertilizer efficiency of pure bagasse ash increased with the ash amount supplied to the substrate. Nevertheless, it was not as effective as fertilization with triple-superphosphate and K2SO4, which we attributed to lower P availability. Co-gasification and co-combustion increased the P mass fraction in all bagasse-based ashes, but its extractability and availability to soybeans increased only when co-processed with chicken manure, because it enabled the formation of readily available Ca-alkali phosphates. Therefore, we recommend co-combusting biomass with alkali-rich residues to increase the availability of P from the ash to plants.
KW - Combustion and gasification
KW - Phosphate extractability and availability
KW - X-ray diffraction (XRD)
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567632
DO - https://doi.org/10.3389/fpls.2022.1041924
SN - 1664-462X
VL - 13
SP - 1
EP - 13
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-56763
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Safarov, J.
A1 - Tuma, Dirk
A1 - Müller, K.
T1 - Thermophysical properties of the paramagnetic ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate over an extended range of temperature and pressure
N2 - The paramagnetic ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate [BMIM][FeCl4] was subject to multiple high-precision thermophysical property measurements under both ambient and high pressure. Density rho(p0,T) / kg m-3 and speed of sound u(p0,T) / m s-1 data at ambient pressure were recorded at temperatures T = (278.15 to 343.16) K using a DSA 5000 M combined vibrating tube densimeter and speed of sound analyser with a standard uncertainty of delta rho(p0,T) = ±0.001 kg m-3 and delta u(p0,T) = ±0.1 m s-1, respectively. High-pressure volumetric (p,rho,T) data were measured on an Anton Paar DMA HPM vibrating tube densimeter at T = (273.16 to 413.15) K and at pressures up to p = 140 MPa with an estimated experimental relative combined average percentage deviation (APD) of delta rho(p,T) / rho(p,T) = ±(0.01 to 0.08) %.
The specific isobaric heat capacity cp(p0,T) / J kg-1 K-1, a caloric property, was determined at T = (273.15 to 413.15) K with an uncertainty delta cp / cp = ±0.5 % using a Perkin Elmer Pyris 1 DSC differential scanning calorimeter. To gain knowledge of transport properties, the dynamic viscosity eta(p0,T) / mPa s at ambient pressure was recorded at T = (275.03 to 413.18) K by an Anton Paar SVM 3000 Stabinger viscometer and additionally an Anton Paar rheometer MCR 302 device with uncertainties of delta eta / eta = ±0.35 % and delta eta / eta = ±1 %, respectively.
The obtained data were first correlated by empirical polynomial equations of state and further processed by the application of classic thermodynamic potentials to determine isothermal compressibility kappa T(p,T) / MPa-1, isobaric thermal expansivity alpha p(p,T) / K-1, thermal pressure coefficient gamma(p,T) / MPa K-1, internal pressure pint(p,T) / MPa, specific heat capacity at constant pressure cp(p,T) / J kg-1 K-1 and at constant volume cv(p,T) / J kg-1 K-1, the difference of isobaric and isochoric heat capacity (cp–cv)(p,T) / J kg-1 K-1, speed of sound u(p,T) / m s-1 and ultimately isentropic exponent kappa s(p,T).
This work extends knowledge about the thermophysical properties of [BMIM][FeCl4] particularly to high temperatures and pressures.
KW - Ionic liquid
KW - Volumetric properties
KW - Transport properties
KW - Caloric properties
PY - 2022
DO - https://doi.org/10.1016/j.molliq.2021.117939
SN - 0167-7322
VL - 346
SP - 1
EP - 16
PB - Elsevier
CY - Amsterdam
AN - OPUS4-54228
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Brüngel, R.
A1 - Rückert, J.
A1 - Müller, P.
A1 - Babick, F.
A1 - Friedrich, C. M.
A1 - Ghanem, A.
A1 - Hodoroaba, Vasile-Dan
A1 - Mech, A.
A1 - Weigel, S.
A1 - Wohlleben, W.
A1 - Rauscher, H.
T1 - NanoDefiner Framework and e-Tool Revisited According to the European Commission’s Nanomaterial Definition 2022/C 229/01
N2 - The new recommended definition of a nanomaterial, 2022/C 229/01, adopted by the European Commission in 2022, will have a considerable impact on European Union legislation addressing chemicals, and therefore tools to implement this new definition are urgently needed. The updated NanoDefiner framework and its e-tool implementation presented here are such instruments, which help stakeholders to find out in a straightforward way whether a material is a nanomaterial or not. They are two major outcomes of the NanoDefine project, which is explicitly referred to in the new definition. This work revisits the framework and e-tool, and elaborates necessary adjustments to make these outcomes applicable for the updated recommendation. A broad set of case studies on representative materials confirms the validity of these adjustments. To further foster the sustainability and applicability of the framework and e-tool, measures for the FAIRification of expert knowledge within the e-tool’s knowledge base are elaborated as well. The updated framework and e-tool are now ready to be used in line with the updated recommendation. The presented approach may serve as an example for reviewing existing guidance and tools developed for the previous definition 2011/696/EU, particularly those adopting NanoDefine project outcomes.
KW - Nanomaterial definition
KW - Nanomaterial categorisation
KW - Nanomaterial regulation
KW - Nanomaterial legislation
KW - Decision support
KW - FAIRification
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571618
DO - https://doi.org/10.3390/nano13060990
SN - 2079-4991
VL - 13
IS - 6 - Special Issue "Identification and Quantification of Nanomaterials"
SP - 1
EP - 16
PB - MDPI
CY - Basel, CH
AN - OPUS4-57161
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wolff, M.
A1 - Wonneberger, R.
A1 - Freiberg, K.E.
A1 - Hertwig, Andreas
A1 - Bonse, Jörn
A1 - Giebeler, L.
A1 - Koitzsch, A.
A1 - Kunz, C.
A1 - Weber, H.
A1 - Hufenbach, J.K.
A1 - Müller, F.A.
A1 - Gräf, S.
T1 - Formation of laser-induced periodic surface structures on Zr-based bulk metallic glasses with different chemical composition
N2 - Bulk metallic glasses (BMG) are amorphous metal alloys known for their unique physical and mechanical properties. In the present study, the formation of femtosecond (fs) laser-induced periodic surface structures (LIPSS) on the Zr-based BMGs Zr46Cu46Al8, Zr61Cu25Al12Ti2, Zr52.5Cu17.9Al10Ni14.6Ti5 (Vit105) and Zr57Cu15.4Al10Ni12.6Nb5 (Vit106) was investigated as a function of their different chemical composition. For this purpose, LIPSS were generated on the sample surfaces in an air environment by fs-laser irradiation (λ = 1025 nm, τ = 300 fs, frep = 100 kHz). The surface topography was characterized by scanning electron microscopy and atomic force microscopy. Moreover, the impact of LIPSS formation on the structure and chemical surface composition was analyzed before and after fs-laser irradiation by X-ray diffraction and X-ray photoelectron spectroscopy as well as by transmission electron microscopy in combination with energy dispersive X-ray spectroscopy. Despite the different chemical composition of the investigated BMGs, the fs-laser irradiation resulted in almost similar properties of the generated LIPSS patterns. In the case of Zr61Cu25Al12Ti2, Vit105 and Vit106, the surface analysis revealed the preservation of the amorphous state of the materials during fs-laser irradiation. The study demonstrated the presence of a native oxide layer on all pristine BMGs. In addition, fs-laser irradiation results in the formation of laser-induced oxide layers of larger thickness consisting of an amorphous ZrAlCu-oxide. The precise laser-structuring of BMG surfaces on the nanoscale provides a versatile alternative to thermoplastic forming of BMG surfaces and is of particular interest for the engineering of functional material surfaces.
KW - Bulk metallic glasses
KW - Femtosecond laser
KW - Laser-induced periodic surface structures (LIPSS)
KW - Chemical analysis
KW - Oxidation
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581799
DO - https://doi.org/10.1016/j.surfin.2023.103305
SN - 2468-0230
VL - 42
SP - 1
EP - 11
PB - Elsevier B.V.
AN - OPUS4-58179
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Deubener, J.
A1 - Behrens, H.
A1 - Müller, Ralf
T1 - An overview on the effect of dissolved water on the viscosity of soda lime silicate melts
N2 - In this review article, the impact of dissolved water on the viscous properties of soda lime silicate melts is addressed against the background of the upcoming switch from natural gas to hydrogen combustion. This change will lead to an increase in the total water content of the glasses by up to 0.4 mol%. In order to better define possible influences of water speciation, water-rich glasses were synthesised under increasing pressure up to the kbar range. It is shown that a distinction must be made between the influence of dissolved OH-groups and H2Omolecules in order to accurately reflect the dependence of isokom temperatures on water content. In addition, an increase of one order of magnitude in the tolerance to higher deformation rates was observed for the range of expected increased water contents during isothermal deformation processes, which is based on the timetemperature superposition principle, i.e. congruent flow curves were determined under isokomal conditions.
KW - Water in glass
KW - Viscosity
KW - Soda lime silicate glass
KW - Shear thinning
KW - Nydrogen melting
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587276
DO - https://doi.org/10.1016/j.nocx.2023.100195
VL - 19
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-58727
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Reinsch, Stefan
A1 - Welter, T.
A1 - Müller, Ralf
A1 - Deubener, J.
T1 - Hydrogen Permeability of Tectosilicate Glasses for Tank Barrier Liners
N2 - The permeation of hydrogen gas was studied in meta-aluminous (tectosilicate) glass powders of Li2O×Al2O3×SiO2 (LAS), Na2O×Al2O3×SiO2 (NAS) and MgO×Al2O3×SiO2 (MAS) systems by pressure loading and vacuum extraction in the temperatures range 210–310 °C. With this method, both the solubility S and the diffusivity D were determined, while the permeability was given by the product SD. For all glasses, S was found to decrease with temperature, while D increased. Since the activation energy of diffusion of H2 molecules exceeded that of dissolution, permeation increased slightly with temperature. When extrapolated to standard conditions (25 °C), the permeability of tectosilicate glasses was found to be only 10-22–10-24 mol H2 (m s Pa)-1, which is 8–10 magnitudes lower than most polymers. Thin glass liners of these compositions are expected to be the most effective barrier for tanks of pressurised hydrogen.
KW - Hydrogen permeation
KW - Aluminosilicate glasses
KW - Hydrogen storage tank
KW - Glass liner
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587284
DO - https://doi.org/10.52825/glass-europe.v1i.425
VL - 1
SP - 1
EP - 11
AN - OPUS4-58728
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dal Molin, E. S.
A1 - Henning, L. M.
A1 - Müller, J. T.
A1 - Smales, Glen Jacob
A1 - Pauw, Brian Richard
A1 - Bekheet, M. F.
A1 - Gurlo, A.
A1 - Simon, U.
T1 - Robocasting of ordered mesoporous silica‐based monoliths: Rheological, textural, and mechanical characterization
N2 - Hierarchically porous, high‐surface‐area silica materials are excellent candidates for multiple applications like catalysis and environmental remediation. Shaping these materials with additive manufacturing (AM) techniques, like robocasting, could enable their use with the benefit of on‐demand, customized shaping and maximizing performance. Herein, ordered mesoporous silica COK‐12 slurries were robocasted into monoliths, containing different ratios of uncalcined COK‐12 and sodium bentonite (0–25 wt.%). The rheology of the mixed slurries is characterized by lower flow indexes (0.69 vs. 0.32) and higher yield stresses (96 vs. 259 Pa) compared to pure COK‐12 ones. Monoliths were printed in woodpile structures and calcined at 600°C. Micro‐CT measurements showed a linear shrinkage of 25% after calcination. Mechanical characterization showed increased uniaxial strength (0.20 ± 0.07 to 1.0 ± 0.3 MPa) with increasing binder/solids ratio from 13 to 25%. The amorphous, mesoporous structure of COK‐12 was retained. The structures exhibited open porosities of 52 ± 4% and showed higher specific mesopore volumes, and increased average mesopore size (6 vs. 8 nm) compared to COK‐12. Small‐angle x‐ray scattering analysis revealed an increased lattice parameter (10.3 vs. 11.0 nm) and reduced wall thickness (3.1 nm vs. 4.1 nm) of the COK‐12 in the monoliths. These properties indicate suitability for their application as porous supports and adsorbents.
KW - Industrial and Manufacturing Engineering
KW - Additive manufacturing
KW - OMS
KW - Porous materials
KW - Robocasting
KW - X-ray scattering
KW - MOUSE
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-582503
DO - https://doi.org/10.1002/nano.202300109
VL - 4
IS - 11-12
SP - 615
EP - 631
PB - Wiley-VCH GmbH
AN - OPUS4-58250
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, W.
A1 - Schweins, R.
A1 - Nöcker, B.
A1 - Kohlbrecher, J.
A1 - Smales, Glen Jacob
A1 - Huber, K.
T1 - Comparative study of the co-assembly behaviour of 3-chloro-4-hydroxy-phenylazo dyes with DTAB
N2 - The co-assembly of three one-fold negatively charged 3-chloro-4-hydroxy-phenylazo dyes (Yellow, Blue and Red) with the cationic surfactant dodecyltrimethylammoniumbromide (DTAB) was studied to probe dye–DTAB binding stoichiometry and assembly morphology. For each dye, phase separation was observed above a given dye : DTAB ratio with the ratio depending on the dye. While Yellow and DTAB showed liquid/liquid phase separation above Yellow : DTAB = 1 : 1.67, crystalline dye–DTAB complexes were observed for Blue–DTAB and Red–DTAB above Blue : DTAB = 1 : 2.56 and Red : DTAB = 1 : 2.94 respecively. In homogeneous solution, UV/vis spectroscopic investigations suggest stochiometries of Yellow : DTAB = 1 : 2, Blue : DTAB = 1 : 3 and Red : DTAB = 1 : 4. It was concluded, that Yellow exhibits the highest dye : DTAB binding stoichiometry in both, dye–surfactant complexes in the 2-phase region and in solution, whereas the lowest dye : DTAB binding stoichiometry was observed for Red–DTAB in both cases. The observed stoichiometries are inversely correlated to the impact dye addition has on the morphology of DTAB micelles. Generally, addition of dye to DTAB micelles leads to a reduction in spontaneous curvature of these micelles and to the formation of triaxial ellipsoidal or cylindrical micelles from oblate ellipsoidal DTAB micelles. At a DTAB concentration of 30 mM and a dye concentration of 5 mM, this effect was most pronounced for Red and least pronounced for Yellow, whilst Blue showed an intermediate effect.
KW - Dye
KW - DTAB
KW - SAXS
KW - Small-angle X-ray scattering
KW - X-ray scattering
KW - Data analysis
KW - Micelle
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576978
DO - https://doi.org/10.1039/D3SM00501A
SN - 1744-683X
VL - 19
IS - 24
SP - 4588
EP - 4598
PB - Royal Society of Chemistry
AN - OPUS4-57697
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Reveron, H.
A1 - Serrano-Munoz, Itziar
A1 - Kupsch, Andreas
A1 - Müller, B.R.
A1 - Chevalier, J.
A1 - Bruno, Giovanni
T1 - Transformation-induced plasticity in zirconia during tensile loading: A combined microscopy and synchrotron X-ray refraction study
N2 - The stress-induced tetragonal to monoclinic (t-m) zirconia phase transformation can provide a certain degree of plasticity to Ceria-stabilized (Ce-TZP) zirconia-based composites. Characterizing and monitoring this phase transition on a millimeter-size range, within the bulk and in-situ remains a challenge. In this work, the mechanical behavior of Ce-TZP based composite was studied in tension, combining microscopy and synchrotron Xray refraction techniques. In contrast with microscopy methods, which only provide surface information, X-ray refraction radiography (SXRR) allowed the visualization of all the transformation bands, over the entire length and thickness of tested specimens, opening up new avenues for in-situ stress-induced t-m transformation studies.
KW - Zirconia
KW - Ceria
KW - Composite
KW - Phase transformation
KW - Plasticity
KW - Synchrotron X-ray refraction
PY - 2024
DO - https://doi.org/10.1016/j.matlet.2024.136445
SN - 0167-577X
SN - 1873-4979
VL - 366
SP - 1
EP - 4
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-59977
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bauer, L.J.
A1 - Wieder, Frank
A1 - Truong, V.
A1 - Förste, F.
A1 - Wagener, Y.
A1 - Jonas, A.
A1 - Praetz, S:
A1 - Schlesiger, C.
A1 - Kupsch, Andreas
A1 - Müller, B.R.
A1 - Kanngießer, B.
A1 - Zaslansky, P.
A1 - Mantouvalou, I.
T1 - Absorption Correction for 3D Elemental Distributions of Dental Composite Materials Using Laboratory Confocal Micro-X-ray Fluorescence Spectroscopy
N2 - Confocal micro-X-ray fluorescence (micro-XRF) spectroscopy facilitates three-dimensional (3D) elemental imaging of heterogeneous samples in the micrometer range. Laboratory setups using X-ray tube excitation render the method accessible for diverse research fields but interpretation of results and quantification remain challenging. The attenuation of X-rays in composites depends on the photon energy as well as on the composition and density of the material. For confocal micro-XRF, attenuation severely impacts elemental distribution information, as the signal from deeper layers is distorted by superficial layers. Absorption correction and quantification of fluorescence measurements in heterogeneous composite samples have so far not been reported. Here, an absorption correction approach for confocal micro-XRF combining density information from microcomputed tomography (micro-CT) data with laboratory X-ray absorption spectroscopy (XAS) and synchrotron transmission measurements is presented. The energy dependency of the probing volume is considered during the correction. The methodology is demonstrated on a model composite sample consisting of a bovine tooth with a clinically used restoration material.
KW - Micro X-ray fluorescence spectroscopy
KW - Dental composite materials
KW - Computed tomography
KW - Absorption correction
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601630
DO - https://doi.org/10.1021/acs.analchem.4c00116
SN - 0003-2700
SN - 1520-6882
VL - 96
IS - 21
SP - 8441
EP - 8449
PB - American Chemical Society Publications
CY - Washington, DC
AN - OPUS4-60163
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -