TY - JOUR A1 - Nguyen, V. Q. A1 - Baynosa, M. L. A1 - Nguyen, V. H. A1 - Tuma, Dirk A1 - Lee, Y. R. A1 - Shim, J.-J. T1 - Solvent-driven morphology-controlled synthesis of highly efficient long-life ZnO/graphene nanocomposite photocatalysts for the practical degradation of organic wastewater under solar light N2 - Metal oxide/graphene photocatalysts have been attracting considerable attention in solving environmental pollution problems because of the limitations of the semiconductor-based photocatalysts. In this study, highly efficient and inexpensive zinc oxide (ZnO) nanoparticles with three different morphologies, such as nanospheres, nanodisks, and nanorods, anchored on reduced graphene oxide (RGO) were synthesized in solvent mixtures with different ethanol to water ratios. Among the three morphologies, the nanospherical ZnO/RGO (sZG) Composite exhibited the highest methylene blue (MB) and rhodamine B removal efficiencies at 99% and 98%, respectively, after only 60 min under low-power (40 W) ultraviolet irradiation at a low catalyst loading of 0.1 g L−1. This nanocomposite also showed excellent photocatalytic stability under UV irradiation, retaining 96% Efficiency even after 15 cycles of MB degradation. Moreover, the sZG composite exhibited a high MB degradation Efficiency of approximately 99% after 100 min at a low catalyst loading of 0.2 g L−1 under solar light illumination. The excellent photocatalytic performance and high stability of this low-cost nanospherical ZnO/RGO Composite exemplarily highlights the potential of sustainable next-generation photocatalysis for treating wastewater containing organic pollutants. KW - Nanocomposite KW - Photocatalyst KW - Dye degradation PY - 2019 DO - https://doi.org/10.1016/j.apsusc.2019.03.262 SN - 0169-4332 SN - 1873-5584 VL - 486 SP - 37 EP - 51 PB - Elsevier B. V. CY - Amsterdam AN - OPUS4-48081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trimpin, Sarah A1 - Yenchick, Frank S. A1 - Lee, Chuping A1 - Hoang, Khoa A1 - Pophristic, Milan A1 - Karki, Santosh A1 - Marshall, Darrell D. A1 - Lu, I-Chung A1 - Lutomski, Corinne A. A1 - El-Baba, Tarick J. A1 - Wang, Beixi A1 - Pagnotti, Vincent S. A1 - Meher, Anil K. A1 - Chakrabarty, Shubhashis A1 - Imperial, Lorelei F. A1 - Madarshahian, Sara A1 - Richards, Alicia L. A1 - Lietz, Christopher B. A1 - Moreno-Pedraza, Abigail A1 - Leach, Samantha M. A1 - Gibson, Stephen C. A1 - Elia, Efstathios A. A1 - Thawoos, Shameemah M. A1 - Woodall, Daniel W. A1 - Jarois, Dean R. A1 - Davis, Eric T.J. A1 - Liao, Guochao A1 - Muthunayake, Nisansala S. A1 - Redding, McKenna J. A1 - Reynolds, Christian A. A1 - Anthony, Thilani M. A1 - Vithanarachchi, Sashiprabha M. A1 - DeMent, Paul A1 - Adewale, Adeleye O. A1 - Yan, Lu A1 - Wager-Miller, James A1 - Ahn, Young-Hoon A1 - Sanderson, Thomas H. A1 - Przyklenk, Karin A1 - Greenberg, Miriam L. A1 - Suits, Arthur G. A1 - Allen, Matthew J. A1 - Narayan, Srinivas B. A1 - Caruso, Joseph A. A1 - Stemmer, Paul M. A1 - Nguyen, Hien M. A1 - Weidner, Steffen A1 - Rackers, Kevin J. A1 - Djuric, Ana A1 - Shulaev, Vladimir A1 - Hendrickson, Tamara L. A1 - Chow, Christine S. A1 - Pflum, Mary Kay H. A1 - Grayson, Scott M. A1 - Lobodin, Vladislav V. A1 - Guo, Zhongwu A1 - Ni, Chi-Kung A1 - Walker, J. Michael A1 - Mackie, Ken A1 - Inutan, Ellen D. A1 - McEwen, Charles N. T1 - New Processes for Ionizing Nonvolatile Compounds in Mass Spectrometry: The Road of Discovery to Current State-of-the-Art N2 - This Perspective covers discovery and mechanistic aspects aswell as initial applications of novel ionization processes for use in massspectrometry that guided us in a series of subsequent discoveries, instrumentdevelopments, and commercialization. Vacuum matrix-assisted ionization onan intermediate pressure matrix-assisted laser desorption/ionization sourcewithout the use of a laser, high voltages, or any other added energy wassimply unbelievable, at first. Individually and as a whole, the variousdiscoveries and inventions started to paint, inter alia, an exciting new pictureand outlook in mass spectrometry from which key developments grew thatwere at the time unimaginable, and continue to surprise us in its simplisticpreeminence. We, and others, have demonstrated exceptional analyticalutility. Our current research is focused on how best to understand, improve, and use these novel ionization processes throughdedicated platforms and source developments. These ionization processes convert volatile and nonvolatile compounds from solid orliquid matrixes into gas-phase ions for analysis by mass spectrometry using, e.g., mass-selected fragmentation and ion mobilityspectrometry to provide accurate, and sometimes improved, mass and drift time resolution. The combination of research anddiscoveries demonstrated multiple advantages of the new ionization processes and established the basis of the successes that lead tothe Biemann Medal and this Perspective. How the new ionization processes relate to traditional ionization is also presented, as wellas how these technologies can be utilized in tandem through instrument modification and implementation to increase coverage ofcomplex materials through complementary strengths. KW - Mass spectrometry PY - 2024 DO - https://doi.org/10.1021/jasms.3c00122 SN - 1879-1123 VL - 35 IS - 12 SP - 2753 EP - 2784 PB - American Chemical Society (ACS) AN - OPUS4-61417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Critical review of the current status of thickness measurements for ultrathin SiO2 on Si - Part V: Results of a CCQM pilot study N2 - Results are reported from a pilot study under the Consultative Committee for Amount of Substance (CCQM) to compare measurements of and resolve any relevant measurement issues in, the amount of thermal SiO2 oxide on (100) and (111) orientation Si wafer substrates in the thickness range 1.5 - 8 nm. As a result of the invitation to participate in this activity, 45 sets of measurements have been made in different laboratories using 10 analytical methods: medium-energy ion scattering spectrometry (MEIS), nuclear reaction analysis (NRA), RBS, elastic backscattering spectrometry (EBS), XPS, SIMS, ellipsometry, grazing-incidence x-ray reflectrometry (GIXRR), neutron reflectometry and transmission electron microscopy (TEM). The measurements are made on separate sets of 10 carefully prepared samples, all of which have been characterised by a combination of ellipsometry and XPS using carefully established reference conditions and reference parameters. The results have been assessed against the National Physical Laboratory (NPL) data and all show excellent linearity. The remaining data sets correlate with the NPL data with average root-mean-square scatters of 0.15 nm, half being better than 0.1 nm and a few at or better than 0.05 nm. Each set of data allows a relative scaling constant and a zero thickness offset to be determined. Each method has an inherent zero thickness offset between 0 nm and 1 nm and it is these offsets, measured here for the first time, that have caused many problems in the past. There are three basic classes of offset: water and carbonadeous contamination equivalent to ~1 nm as seen by ellipsometry; adsorbed oxygen mainly from water at an equivalent thickness of 0.5 nm as seen by MEIS, NRA, RBS and possibly GIXRR; and no offset as seen by XPS using the Si 2p peaks. Each technique has a different uncertainty for the scaling constant and consistent results have been achieved. X-Ray photoelectron spectroscopy has large uncertainties for the scaling constant but a high precision and, critically, if used correctly, has zero offset. Thus, a combination of XPS and the other methods allows the XPS scaling constant to be determined with low uncertainty, traceable via the other methods. XPS laboratories returning results early were invited to test a new reference procedure. All showed very significant improvements. The reference attenuation lengths thus need scaling by 0.986 ± 0.009 (at an expansion factor of 2) deduced from the data for the other methods. Several other methods have small offsets and, to the extent that these can be shown to be constant or measurable, then these methods will also show low uncertainty. Recommendations are provided for parameters for XPS, MEIS, RBS and NRA to improve their accuracy. KW - Calibration KW - Ellipsometry KW - GIXRR KW - Interlaboratory study KW - MEIS KW - Neutron reflectometry KW - NRA KW - RBS KW - Silicon dioxide KW - SIMS KW - XPS PY - 2004 DO - https://doi.org/10.1002/sia.1909 SN - 0142-2421 SN - 1096-9918 VL - 36 IS - 9 SP - 1269 EP - 1303 PB - Wiley CY - Chichester AN - OPUS4-5549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nguyen, H. G. A1 - Toman, B. A1 - van Zee, R. A1 - Prinz, Carsten A1 - Thommes, M. A1 - Ahmad, R. A1 - Kiska, D. A1 - Salinger, J. A1 - Walton, I. A1 - Walton, K. A1 - Broom, D. A1 - Benham, M. A1 - Ansari, H. A1 - Pini, R. A1 - Petit, C. A1 - Adolphs, J. A1 - Schreiber, A. A1 - Shigeoka, T. A1 - Konishi, Y. A1 - Nakai, K. A1 - Henninger, M. A1 - Petrzik, T. A1 - Kececi, C. A1 - Martis, V. A1 - Paschke, T. A1 - Mangano, E. A1 - Brandani, S. T1 - Reference isotherms for water vapor sorption on nanoporous carbon: results of an interlaboratory study N2 - This paper reports the results of an international interlaboratory study sponsored by the Versailles Project on Advanced Materials and Standards (VAMAS) and led by the National Institute of Standards and Technology (NIST) on the measurement of water vapor sorption isotherms at 25 °C on a pelletized nanoporous carbon (BAM-P109, a certified reference material). Thirteen laboratories participated in the study and contributed nine pure water vapor isotherms and four relative humidity isotherms, using nitrogen as the carrier gas. From these data, reference isotherms, along with the 95% uncertainty interval (Uk=2), were determined and are reported in a tabular format. KW - BAM-P109 KW - Interlaboratory study KW - Nanoporous carbon KW - Reference isotherm KW - VAMAS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576560 DO - https://doi.org/10.1007/s10450-023-00383-1 SN - 0929-5607 SP - 1 EP - 12 PB - Springer CY - Heidelberg AN - OPUS4-57656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Greenhalgh, E.S. A1 - Ankersen, J. A1 - Asp, L. E. A1 - Bismarck, A. A1 - Fontana, Q.P.V. A1 - Houlle, M. A1 - Kalinka, Gerhard A1 - Kucernak, A. A1 - Mistry, M. A1 - Nguyen, S. A1 - Qian, H. A1 - Shaffer, M.S.P. A1 - Shirshova, N. A1 - Steinke, J.H.G. A1 - Wienrich, Malte T1 - Mechanical, electrical and microstructural characterisation of multifunctional structural power composites N2 - Multifunctional composites which can fulfil more than one role within a system have attracted considerable interest. This work focusses on structural supercapacitors which simultaneously carry mechanical load whilst storing/delivering electrical energy. Critical mechanical properties (in-plane shear and in-plane compression performance) of two monofunctional and four multifunctional materials were characterised, which gave an insight into the relationships between these properties, the microstructures and fracture processes. The reinforcements included baseline T300 fabric, which was then either grafted or sized with carbon nanotubes, whilst the baseline matrix was MTM57, which was blended with ionic liquid and lithium salt (two concentrations) to imbue multifunctionality. The resulting composites exhibited a high degree of matrix heterogeneity, with the ionic liquid phase preferentially forming at the fibres, resulting in poor matrix-dominated properties. However, fibre-dominated properties were not depressed. Thus, it was demonstrated that these materials can now offer weight savings over conventional monofunctional systems when under modest loading. KW - Carbon fibres KW - Functional composites KW - Mechanical properties KW - Elastic properties KW - Fractography PY - 2014 DO - https://doi.org/10.1177/0021998314554125 SN - 0021-9983 SN - 1530-793X SP - 1 EP - 12 PB - Sage CY - London AN - OPUS4-34567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baynosa, M. L. A1 - Mady, A. H. A1 - Nguyen, V. Q. A1 - Kumar, D. R. A1 - Sayed, M. S. A1 - Tuma, Dirk A1 - Shim, J.-J. T1 - Eco-friendly synthesis of recyclable mesoporous zinc ferrite@reduced graphene oxide nanocomposite for efficient photocatalytic dye degradation under solar radiation N2 - Zinc ferrite and graphene composites have attracted considerable attention in wastewater treatment. In this work, a magnetically separable mesoporous composite of ZnFe2O4 nanoparticles (NPs) and reduced graphene oxide (rGO) was prepared through a simple and eco-friendly method with pure water as solvent and without the need for subsequent thermal treatment. Uniformly dispersed ZnFe2O4 NPs on the surface of rGO sheets exhibited good crystallinity and a large BET specific surface area. These factors contributed to good photocatalytic performance of the composite for the degradation of methylene blue (MB) under simulated solar-light radiation, increased adsorptivity, increased separation efficiency of the photo-excited charges on the surface of the catalyst, and broadened light-absorption range of the composite. Efficient interfacial interaction between the ZnFe2O4 NPs and rGO sheets resulted in synergistic effects. The magnetically separable ZnFe2O4@rGO nanocomposite proved an efficient and stable catalyst in three consecutive photodegradation cycles for MB dye in aqueous solution under solar radiation. In addition, the synthesis method proposed in this study could be scaled-up easily due to the simplicity of the process, the lack of a toxic reagent, and the use of low temperatures. KW - Zinc ferrite KW - Reduced graphene oxide KW - Nanocomposite KW - Wastewater PY - 2020 DO - https://doi.org/10.1016/j.jcis.2019.11.018 SN - 0021-9797 VL - 561 SP - 459 EP - 469 PB - Elsevier B. V. CY - Amsterdam AN - OPUS4-50211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Joseph, A. A1 - Bernardes, C. E. S. A1 - Druzhinina, A. I. A1 - Varushchenko, R. M. A1 - Nguyen, Thi Yen A1 - Emmerling, Franziska A1 - Yuan, L. A1 - Dupray, V. A1 - Coquerel, G. A1 - Minas da Piedade, M. E. T1 - Polymorphic phase transition in 4′-hydroxyacetophenone: Equilibrium temperature, kinetic barrier, and the relative stability of Z′=1 and Z′=2 forms N2 - Particularly relevant in the context of polymorphism is understanding how structural, thermodynamic, and kinetic factors dictate the stability domains of polymorphs, their tendency to interconvert through phase transitions, or their possibility to exist in metastable states. These three aspects were investigated here for two 4′-hydroxyacetophenone (HAP) polymorphs, differing in crystal system, space group, and number and conformation of molecules in the asymmetric unit. The results led to a ΔfGm°-T phase diagram highlighting the enantiotropic nature of the system and the fact that the Z′=1 polymorph is not necessarily more stable than its Z′=2 counterpart. It was also shown that the form II → form I transition is entropy driven and is likely to occur through a nucleation and growth mechanism, which does not involve intermediate phases, and is characterized by a high activation energy. Finally, although it has been noted that conflicts between hydrogen bond formation and close packing are usually behind exceptions from the hypothesis of Z′=1 forms being more stable than their higher Z′ analogues, in this case, the HAP polymorph with stronger hydrogen bonds (Z′=2) is also the one with higher density. KW - Polymorphism KW - Polymorphic transition KW - 4'-hydroxyacetophenone PY - 2017 DO - https://doi.org/10.1021/acs.cgd.6b01876 SN - 1528-7483 SN - 1528-7505 VL - 17 IS - 4 SP - 1918 EP - 1932 PB - ACS AN - OPUS4-40167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - You, Yi A1 - Song, L. A1 - Young, M.D. A1 - van der Wielen, M. A1 - Evans-Nguyen, T. A1 - Riedel, Jens A1 - Shelley, J.T. T1 - Unsupervised Reconstruction of Analyte-Specific Mass Spectra Based on Time-Domain Morphology with a Modified Cross-Correlation Approach N2 - Concomitant species that appear at the same or very similar times in a mass-spectral analysis can clutter a spectrum because of the coexistence of many analyte-related ions (e.g., molecular ions, adducts, fragments). One method to extract ions stemming from the same origin is to exploit the chemical information encoded in the time domain, where the individual temporal appearances inside the complex structures of chronograms or chromatograms differ with respect to analytes. By grouping ions with very similar or identical time-domain structures, single-component mass spectra can be reconstructed, which are much easier to interpret and are library-searchable. While many other approaches address similar objectives through the Pearson’s correlation coefficient, we explore an alternative method based on a modified cross-correlation algorithm to compute a metric that describes the degree of similarity between features inside any two ion chronograms. Furthermore, an automatic workflow was devised to be capable of categorizing thousands of mass-spectral peaks into different groups within a few seconds. This approach was tested with direct mass-spectrometric analyses as well as with a simple, fast, and poorly resolved LC–MS analysis. Single-component mass spectra were extracted in both cases and were identified based on accurate mass and a mass-spectral library search. KW - Mass-Spectral Reconstruction KW - Mass Spectrometry KW - Correlation PY - 2021 DO - https://doi.org/10.1021/acs.analchem.0c04396 VL - 93 IS - 12 SP - 5009 EP - 5014 PB - ACS AN - OPUS4-52467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hobmeier, K. A1 - Cantone, M. A1 - Nguyen, Q. A. A1 - Pflüger-Grau, K. A1 - Kremling, A. A1 - Kunte, Hans-Jörg A1 - Pfeiffer, F. A1 - Marin-Sanguino, A. T1 - Adaptation to varying salinity in Halomonas elongata: Much more than ectoine accumulation N2 - The halophilic γ-proteobacterium Halomonas elongata DSM 2581T thrives at salt concentrations well above 10 % NaCl (1.7 M NaCl). A well-known osmoregulatory mechanism is the accumulation of the compatible solute ectoine within the cell in response to osmotic stress. While ectoine accumulation is central to osmoregulation and promotes resistance to high salinity in halophilic bacteria, ectoine has this effect only to a much lesser extent in non-halophiles. We carried out transcriptome analysis of H. elongata grown on two different carbon sources (acetate or glucose), and low (0.17 M NaCl), medium (1 M), and high salinity (2 M) to identify additional mechanisms for adaptation to high saline environments. To avoid a methodological bias, the transcripts were evaluated by applying two methods, DESeq2 and Transcripts Per Million (TPM). The differentially transcribed genes in response to the available carbon sources and salt stress were then compared to the transcriptome profile of Chromohalobacter salexigens, a closely related moderate halophilic bacterium. Transcriptome profiling supports the notion that glucose is degraded via the cytoplasmic Entner-Doudoroff pathway, whereas the Embden-Meyerhoff-Parnas pathway is employed for gluconeogenesis. The machinery of oxidative phosphorylation in H. elongata and C. salexigens differs greatly from that of non-halophilic organisms, and electron flow can occur from quinone to oxygen along four alternative routes. Two of these pathways via cytochrome bo' and cytochrome bd quinol oxidases seem to be upregulated in salt stressed cells. Among the most highly regulated genes in H. elongata and C. salexigens are those encoding chemotaxis and motility proteins, with genes for chemotaxis and flagellar assembly severely downregulated at low salt concentrations. We also compared transcripts at low and high-salt stress (low growth rate) with transcripts at optimal salt concentration and found that the majority of regulated genes were down-regulated in stressed cells, including many genes involved in carbohydrate metabolism, while ribosome synthesis was up-regulated, which is in contrast to what is known from non-halophiles at slow growth. Finally, comparing the acidity of the cytoplasmic proteomes of non-halophiles, extreme halophiles and moderate halophiles suggests adaptation to an increased cytoplasmic ion concentration of H. elongata. Taken together, these results lead us to propose a model for salt tolerance in H. elongata where ion accumulation plays a greater role in salt tolerance than previously assumed. KW - Ectoine KW - Osmoadaptation PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545608 DO - https://doi.org/10.3389/fmicb.2022.846677 SN - 1664-302X VL - 13 SP - 1 EP - 19 PB - Frontiers Media CY - Lausanne AN - OPUS4-54560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Przondziono, R. A1 - Timothy, J.J. A1 - Nguyen, M. A1 - Weise, Frank A1 - Breitenbücher, R. A1 - Meschke, G. A1 - Meng, Birgit T1 - Vorschädigungen in Beton infolge zyklischer Beanspruchungen und deren Auswirkung auf Transportprozesse im Hinblick auf eine schädigende AKR N2 - Auf Grundlage der Zielsetzung der Forschergruppe 1498 beschäftigt sich dieser Beitrag mit den Auswirkungen einer zyklischen mechanischen Belastung im Vierpunktbiegeversuch auf das Transportverhalten in Betongefüge. Hierzu wurde zunächst die Degradation des Mikrogefüges mittels Ultraschallmessungen sowie rissmikroskopischen Untersuchungen an Dünnschliffen charakterisiert. Mit dem Ziel der numerischen Modellbildung wurden Untersuchungen zum Wassereindringverhalten durchgeführt. Es wurden u. a. das Wassereindringverhalten über die Zeit und der Einfluss von Vorschädigungen experimentell geprüft. Basierend auf den gewonnenen Erkenntnissen zu den Einzelprozessen des Ionentransports in poröses Gefüge wurde ein mikromechanisches Mehrskalenmodell entwickelt, welches es ermöglicht, die Wirkung der Vorschädigung auf gekoppelte Feuchte- und Ionentransportprozesse vorherzusagen. Das Modell berücksichtigt die Topologie und räumliche Verteilung der Mikrorisse und deren Einfluss auf die Ionendiffusivität. Die numerische Simulation liefert bei anisotroper Verteilung der Mikrorisse eine erhöhte Alkali-Eindringtiefe. ---------------------------------------------------------------------------------------------------------------------------------- According to the goals of the research group 1498, this paper deals with the effects of cyclic flexural loading in a four-point bending test on the fluid transport processes within a concrete structure. Therefore, the degradation of the microstructure is characterized through ultrasonic wave measurements as well as microscopic crack analysis. In order to numerically model these processes, experiments on the penetration behavior of water into the concrete were carried out. The penetration behavior over time as well as the influence of degradation on the water transport were investigated. To predict the influence of concrete degradation on alkali diffusivity, a multi-scale continuum micromechanics model is incorporated into the numerical model, which accounts for the topology and the three-dimensional distribution of microcracks. As expected, the numerical simulation predicts larger alkali-penetration in pre-damaged concrete. Regarding the micro-crack distribution, an anisotropic distribution of micro-cracks tangential to the direction of the alkali and water flux increases their penetration depth. KW - Alkali-Kieselsäure-Reaktion KW - Baustoffe KW - Degradation KW - Ionentransport KW - Mikromechanik KW - Modellierung KW - Straßenbeton KW - Transportprozesse KW - Vorschädigung KW - zyklische Belastung KW - Korrosion KW - Versuche KW - Fahrbahn KW - Cyclic loading KW - Transport process KW - Schädigende AKR KW - ASR damage PY - 2015 DO - https://doi.org/10.1002/best.201400095 SN - 0005-9900 SN - 1437-1006 VL - 110 IS - 1 SP - 3 EP - 12 PB - Ernst CY - Berlin AN - OPUS4-33039 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kosslick, H. A1 - Pitsch, I. A1 - Deutsch, J. A1 - Pohl, M.-M. A1 - Schulz, A. A1 - Vu, A.T. A1 - Nguyen, D.T. A1 - Frunza, L. A1 - Jäger, Christian T1 - Improved large mesoporous ordered molecular sieves - Stabilization and acid/base functionalization N2 - The preparation of nanoporous materials with enhanced stability using an improved synthesis route using reactive inorganic silica and alumina species is reported. This way improved mesoporous molecular sieves were obtained. The synthesized aluminum substituted mesoporous molecular materials (Al-MMS) contain very large pores of 50–200 Å size combined with an improved pore wall thickness. Increased wall thickness and Al substitution lead to an improved chemical stability against alkaline solution. The textural, structural and acid properties are investigated by physico-chemical methods. The catalytic performance acidic materials was tested in the benzoylation reaction; amino functionalized materials were studied in the base catalyzed Michael addition. KW - Nanoporous molecular sieve KW - Al substitution KW - Stability KW - Synthesis KW - Acidity KW - Catalysis PY - 2010 DO - https://doi.org/10.1016/j.cattod.2010.03.005 SN - 0920-5861 VL - 152 IS - 1-4 SP - 54 EP - 60 PB - Elsevier CY - Amsterdam AN - OPUS4-23960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Iqbal, S. A1 - Mady, A. H. A1 - Kim, Y.-I. A1 - Javed, U. A1 - Shafi, P. M. A1 - Nguyen, V. Q. A1 - Hussain, I. A1 - Tuma, Dirk A1 - Shim, J.-J. T1 - Self-templated hollow nanospheres of B-site engineered non-stoichiometric perovskite for supercapacitive energy storage via anion-intercalation mechanism N2 - The continual increase in energy demand and inconsistent supply have attracted attention towards sustainable energy storage/conversion devices, such as electrochemical capacitors with high energy densities and power densities. Perovskite oxides have received significant attention as anion-intercalation electrode materials for electrochemical capacitors. In this study, hollow nanospheres of nonstoichiometric cubic perovskite fluorides, KNi1-xCoxF3-delta (x = 0.2; delta = 0.33) (KNCF-0.2) have been synthesized using a localized Ostwald ripening. The electrochemical performance of the non-stoichiometric perovskite has been studied in an aqueous 3 M KOH electrolyte to categorically investigate the fluorine-vacancy-mediated charge storage capabilities. High capacities up to 198.55 mA h g-1 or 714.8 C g-1 (equivalent to 1435 F g-1) have been obtained through oxygen anion-intercalation mechanism (peroxide pathway, O-). The results have been validated using ICP (inductively coupled Plasma mass spectrometry) analysis and cyclic voltammetry. An asymmetric supercapacitor device has been fabricated by coupling KNCF-0.2 with activated carbon to deliver a high energy density of 40 W h kg-1 as well as excellent cycling stability of 98 % for 10,000 cycles. The special attributes of hollow-spherical, non-stoichiometric perovskite (KNCF-0.2) have exhibited immense promise for their usability as anion-intercalation type electrodes in supercapacitors. KW - Nanospheres KW - Perovskite KW - Supercapacitor PY - 2021 DO - https://doi.org/10.1016/j.jcis.2021.03.147 SN - 0021-9797 VL - 600 SP - 729 EP - 739 PB - Elsevier Inc. CY - Amsterdam AN - OPUS4-52873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmid, C. A1 - Falkenhagen, Jana A1 - Beskers, T.F. A1 - Nguyen, L.-T.T. A1 - Wilhelm, M. A1 - Du Prez, F.E. A1 - Barner-Kowollik, C. T1 - Multi-block polyurethanes via RAFT end-group switching and their characterization by advanced hyphenated techniques N2 - The detailed characterization of poly(styrene)-b-poly(tetrahydrofuran) (pS-b-pTHF) multiblock copolymers (17800 g mol-1 ≤ Mn ≤ 46800 g mol-1) generated via urethane linkages is presented. The synthesis of the block copolymers is enabled via a mechanistic switch of the thiocarbonyl thio end group of a poly(styrene) to dihydroxyl terminated polymers that subsequently react with a diisocyanate terminated polytetrahydrofuran based prepolymer to form multiblock copolymer structures. The characterization of the multiblock copolymers and their substructures includes size exclusion chromatography (SEC), liquid chromatography at critical conditions (LCCC), nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy as well as matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. To obtain even further details of the polymer size and its composition, SEC with triple detection as well as newly developed SEC coupled online to IR spectroscopy was carried out. The quantification of the average block fractions via online SEC-IR (41–61 mol % pTHF) is in very good agreement with the results obtained via NMR spectroscopy (39–66 mol % pTHF). PY - 2012 DO - https://doi.org/10.1021/ma301117k SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 16 SP - 6353 EP - 6362 PB - American Chemical Society CY - Washington, DC AN - OPUS4-26942 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vo, P. H.N. A1 - Vogel, Christian A1 - Nguyen, H. T.M. A1 - Hamilton, B. R. A1 - Thai, P. K. A1 - Roesch, Philipp A1 - Simon, Franz-Georg A1 - Mueller, J. F. T1 - µ-X-ray fluorescence (XRF) and fluorine K-edge µ-X-ray absorption near-edge structure (XANES) spectroscopy for detection of PFAS distribution in the impacted concrete N2 - An improved understanding of the distribution of per- and polyfluoroalkyl substances (PFAS) in PFAS-impacted concrete is important for risk management and decontamination of PFAS. This study incorporates µ-X-ray fluorescence (µ-XRF) and fluorine K-edge µ-X-ray absorption near-edge structure (µ-XANES) spectroscopy to gain non-destructive insights into PFAS distribution in the impacted concrete. The μ-XRF and μ-XANES spectroscopy provided additional details on the detection of PFAS, which were not detected by the desorption electrospray ionization (DESI) imaging method conducted previously. The shorter chain PFAS were found on the top part of the concrete core (0.5 cm), and longer chain PFAS were mostly at the bottom part of the concrete core (5 cm). The inorganic fluorine fraction was also detected, and it likely hampered the detection of organic fluorine such as PFAS in the concrete. Thus, this non-destructive technique is an complementary approach to detect PFAS in contaminated concrete. KW - Beton KW - Per- and Polyfluoroalkyl substances (PFAS) KW - XANES spectroscopy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-616711 DO - https://doi.org/10.1016/j.hazl.2024.100134 SN - 2666-9110 VL - 5 SP - 1 EP - 5 PB - Elsevier B.V. AN - OPUS4-61671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -