TY - JOUR A1 - Nadejde, C. A1 - Neamtu, M. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf A1 - Paul, Andrea A1 - Ababei, G. A1 - Panne, Ulrich T1 - Tannic acid- and natural organic matter-coated magnetite as green Fenton-like catalysts for the removal of water pollutants N2 - The use of magnetic materials as heterogeneous catalysts has attracted increasing attention in the last years since they proved to be promising candidates for water treatment. In the present study, two types of surface-modified magnetite (Fe3O4) nanoparticles, coated with non-hazardous naturally occurring agents—either tannic acid (TA) or dissolved natural organic matter—were evaluated as magnetic heterogeneous catalysts. Chemical synthesis (co-precipitation) was chosen to yield the nanocatalysts due to its well-established simplicity and efficiency. Subsequently, the properties of the final products were fully assessed by various characterization techniques. The catalytic activity in heterogeneous oxidation of aqueous solutions containing a model pollutant, Bisphenol A (BPA), was comparatively studied. The effect of operational parameters (catalyst loading, H2O2 dosage, and UV light irradiation) on the Degradation performance of the oxidation process was investigated. The optimum experimental parameters were found to be 1.0 g/L of catalysts and 10 mM H2O2, under UV irradiation. The highest mineralization rates were observed for Fe3O4-TA catalyst. More than 80 % of BPA was removed after 30 min of reaction time under the specified experimental conditions. The obtained results showed that the two catalysts studied here are suitable candidates for the removal of pollutants in wastewaters by means of heterogeneous reaction using a green sustainable treatment method. KW - Nanocatalysts KW - Photo-Fenton oxidation KW - Wastewater KW - Bisphenol A degradation KW - Environment KW - Mitigation PY - 2015 UR - http://link.springer.com/article/10.1007/s11051-015-3290-0 DO - https://doi.org/10.1007/s11051-015-3290-0 VL - 17 IS - 12 SP - 476 (1) EP - 476 (10) PB - Springer AN - OPUS4-38758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Hodoroaba, Vasile-Dan A1 - Mielke, Johannes T1 - Techniques evaluation report for selection of characterisation methods N2 - This report is the result of a comprehensive study on the available CMs which come potentially in question for the reliable analysis of the number based size distribution of a nanomaterial according to the EC recommendation for a definition of nanomaterial. Based on the performance criteria already established in NanoDefine the potential CMs are evaluated according to studies available in the literature as well as following the expertise of the NanoDefine consortium partners. The specific advantages and disadvantages of each method with respect to its applicability to the scope of NanoDefine are particularly highlighted. An CM evaluation table is produced so that the mostly suited CMs with respect to the EC definition can be grouped and recommended to the corresponding NanoDefine work packages for further specific development (improvement and adaption), or for direct validation and standardisation, respectively. The actual evaluation report including the recommended CMs will be revised and, if necessary, eventually updated at the mid time of the project. The update will be jointly discussed in the NanoDefine consortium on the basis of the results of testing the methods on the NanoDefine real world materials. KW - Nanomaterial KW - Characterization method KW - EC definition PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-389473 UR - http://www.nanodefine.eu/publications/reports/NanoDefine_TechnicalReport_D3.1.pdf SP - D3.1, 1 EP - 57 CY - Wageningen, The Netherlands AN - OPUS4-38947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert A1 - Winkelmann, Aimo T1 - The challenge of band detection N2 - The presentation demonstrates different traps which are related to the detection of Kikuchi bands in EBSD patterns. T2 - EBSD 2015 CY - Glasgow, UK DA - 30.03.2015 KW - Electron backscatter diffraction KW - Image processing KW - Pseudo symmerty KW - Crystal lattice KW - Pyrite KW - Pattern matching KW - Misindexing PY - 2015 AN - OPUS4-37805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bruno, Giovanni A1 - Shyam, A. A1 - Watkins, T. R. A1 - Pandey, A. A1 - Lara-Curzio, E. A1 - Parish, C. M. A1 - Stafford, R. J. T1 - The effect of porosity and microcracking on the thermomechanical properties of cordierite N2 - The effect of porosity and microcracking on the mechanical properties (strength, fracture toughness,Young’s modulus, and fracture energy) and thermal expansion of diesel particulate filter (DPF) gradecordierite materials has been investigated. A method to deconvolute the effect of porosity and microc-racking on Young’s modulus is proposed. In addition, the microcrack density and the pore morphologyfactor are calculated by applying a micromechanical differential scheme. The values of the investigatedmechanical properties are shown to decrease with an increase in porosity, but the thermal expansionvalues are insensitive to porosity. The variation in mechanical properties as a function of porosity leadsto distinct porosity dependence of thermal shock resistance for crack initiation and crack propagationfor DPF grade synthetic cordierite. KW - Diesel particulate filter KW - Cordierite KW - Porosity KW - Microcracking KW - Micromechanical differential scheme PY - 2015 DO - https://doi.org/10.1016/j.jeurceramsoc.2015.08.014 VL - 2015/35 IS - 16 SP - 4557 EP - 4566 PB - Elsevier Ltd. AN - OPUS4-37973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kabelitz, Anke A1 - de Oliveira Guilherme Buzanich, Ana A1 - Joester, Maike A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Bienert, Ralf A1 - Schulz, K. A1 - Schmack, R. A1 - Kraehnert, R. A1 - Emmerling, Franziska T1 - Time-resolved in situ studies on the formation mechanism of iron oxide nanoparticles using combined fast-XANES and SAXS N2 - The reaction of iron chlorides with an alkaline reagent is one of the most prominent methods for the synthesis of iron oxide nanoparticles. We studied the particle formation mechanism using triethanolamine as reactant and stabilizing agent. In situ fast-X-ray absorption near edge spectroscopy and small-angle X-ray scattering provide information on the oxidation state and the structural information at the same time. In situ data were complemented by ex situ transmission electron microscopy, wide-angle X-ray scattering and Raman analysis of the formed nanoparticles. The formation of maghemite nanoparticles (γ-Fe2O3) from ferric and ferrous chloride was investigated. Prior to the formation of these nanoparticles, the formation and conversion of intermediate phases (akaganeite, iron(II, III) hydroxides) was observed which undergoes a morphological and structural collapse. The thus formed small magnetite nanoparticles (Fe3O4) grow further and convert to maghemite with increasing reaction time. KW - oxidation state KW - structural information KW - maghemite PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-351376 DO - https://doi.org/10.1039/C5CE01585E SN - 1466-8033 VL - 17 IS - 44 SP - 8463 EP - 8470 CY - London, UK AN - OPUS4-35137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hartmann, S. A1 - Shaporin, A. A1 - Hermann, S. A1 - Bonitz, J. A1 - Heggen, M. A1 - Meszmer, P. A1 - Sturm, Heinz A1 - Hölck, O. A1 - Blaudeck, T. A1 - Schulz, S. E. A1 - Mehner, J. A1 - Gessner, T. A1 - Wunderle, B. T1 - Towards nanoreliability of CNT-based sensor applications: Investigations of CNT-metal interfaces combining molecular dynamics simulations, advanced in situ experiments and analytics N2 - In this paper we present results of our recent efforts to understand the mechanical interface behaviour of single-walled carbon nanotubes (CNTs) embedded in metal matrices. We conducted experimental pull-out tests of CNTs embedded in Pd or Au and found Maximum forces in the range 10 - 102 nN. These values are in good agreement with forces obtained from molecular Dynamics simulations taking into account surface functional Groups (SFGs) covalently linked to the CNT material. The dominant failure mode in experiment is a CNT rupture, which can be explained with the presence of SFGs. To qualify the existence of SFGs on our used CNT material, we pursue investigations by means of fluorescence labeling of surface species in combination with Raman imaging. We also report of a tensile test system to perform pull-out tests inside a transmission electron microscope to obtain in situ images of CNT-metal interfaces under mechanical loads at the atomic scale. T2 - 2015 16th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems CY - Budapest, Hungary DA - 20.4.2015 KW - Carbon nanotube CNT KW - Metal matrix KW - Pull-out test KW - Molecular dynamics simulation KW - Surface functional groups KW - Fluorescence labeling KW - Raman imaging KW - Tensile test inside a TEM PY - 2015 SN - 978-1-4799-9950-7 VL - 2015 SP - 1 EP - 8 PB - IEEE AN - OPUS4-37625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maiwald, Michael A1 - Meyer, Klas A1 - Zientek, Nicolai T1 - Towards online reaction monitoring with fully automated NMR data evaluation and modelling - Current results from simultaneous 19F-1H medium resolution NMR experiments N2 - NMR Process Monitoring Towards an automated field integration T2 - 3rd Practical Applications of NMR in Industry Conference (PANIC) - Mestrelab users' meeting CY - La Jolla, CA, USA DA - 08.02.2015 KW - Online NMR spectroscopy KW - Reaction monitoring KW - Prozessanalytik KW - Process analytical technology PY - 2015 AN - OPUS4-36145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Guo, Y. A1 - Lippitz, Andreas A1 - Saftien, P. A1 - Unger, Wolfgang A1 - Kemnitz, E. T1 - Tuning the surface properties of novel ternary iron(III) fluoride-based catalysts using the template effect of the matrix N2 - Sol–gel prepared ternary FeF3–MgF2 materials have become promising heterogeneous catalysts due to their porosity and surface Lewis/Brønsted acidity (bi-acidity). Despite the good catalytic performance, nanoscopic characterisations of this type of material are still missing and the key factors controlling the surface properties have not yet been identified, impeding both a better understanding and further development of ternary fluoride catalysts. In this study, we characterised the interaction between the bi-acidic component (FeF3) and the matrix (MgF2) on the nano-scale. For the first time, the formation pathway of FeF3–MgF2 was profiled and the template effect of MgF2 during the synthesis process was discovered. Based on these new insights two novel materials, FeF3–CaF2 and FeF3–SrF2, were established, revealing that with decreasing the atomic numbers (from Sr to Mg), the ternary fluorides exhibited increasing surface acidity and surface area but decreasing pore size. These systematic changes gave rise to a panel of catalysts with tuneable surface and bulk properties either by changing the matrix alkaline earth metal fluoride or by adjusting their ratios to Fe or both. The template effect of the alkaline earth metal fluoride matrix was identified as the most probable key factor determining the surface properties and further influencing the catalytic performance in ternary fluoride based catalysts, and paves the way to targeted design of next-generation catalysts with tunable properties. KW - Catalysis KW - Surface analysis KW - XPS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-327410 DO - https://doi.org/10.1039/c4dt03229b SN - 1477-9226 SN - 1477-9234 SN - 1364-5447 VL - 44 IS - 11 SP - 5076 EP - 5085 PB - RSC CY - Cambridge AN - OPUS4-32741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grothe, Sven T1 - Ultrasonic signal evaluation used to detect weather-related temperature changes in a concrete specimen N2 - Ultrasonic measurement evaluation methods have been proven to be effective for detection of subtle changes, caused by temperature, load or moisture. However, for its application outdoors it is necessary to analyse unavoidable influences, such as weather. Therefore an ultrasonic monitoring system with 40 ultrasonic sensors (20 transmitters, 20 receivers; 25 kHz central frequenzy) has been implemented on a concrete specimen (4×5×0.8m3), that is exposed to weather conditions. Data from 400 sensor combinations was collected over a period of six months with an interval of two hours. The data was evaluated by both qualitative (correlation techniques) and quantitative (ultrasonic velocity changes via Coda Wave Interferometry and time of flight method) evaluation methods and compared to the temperature changes caused by weather. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346398 UR - https://www.ndt.net/?id=18336 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Wolf, Julia A1 - Mielentz, Frank A1 - Wiggenhauser, Herbert T1 - Using embedded ultrasonic sensors for active and passive concrete monitoring N2 - Challenging new constructions and ageing infrastructure are increasing the demand for permanent monitoring of loads and condition. Various methods and sensors are used for this purpose. But the technologies available today have difficulties in detecting slowly progressing locally confined damages. Extensive investigations or instrumentations are required so far for this purpose. In this study we present new sensors and data processing methods for ultrasonic transmission, which can be used for non-destructive long term monitoring of concrete. They can be mounted during construction or thereafter. Larger volumes can be monitored by a limited number of sensors for changes of material properties. The principles of ultrasonic transmission and influencing factors are presented. This latter include load, damages as well as environmental parameters as temperature or moisture. Various methods for data processing, e. g. coda wave interferometry are introduced. They allow the detection of very small changes in the medium. The embedded sensors are shown including mounting and operation. Application examples so far include small scale laboratory freeze-thaw experiments, localizing loads in larger concrete models, monitoring load effects on real structures as well as detecting acoustic events. Some sensors are operating already for several years. The sensors can be used as transmitter or receivers or switched between both roles. While most of the previous experiments have been active (at least one sensor serving as transmitter), new studies show that the sensors are useful as well for passive measurements, e. g. in acoustic emission or time reversal experiments. Besides application in civil engineering our setups can also be used for model studies in geosciences. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - SHM KW - Monitoring KW - Ultrasound concrete KW - Embedded sensors PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-344652 UR - http://www.ndt.net/?id=18408 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -