TY - JOUR A1 - Henning, L. M. A1 - Diaz Cubas, D. A1 - Colmenares, M. G. A1 - Schmidt, J. A1 - Bekheet, M. F. A1 - Pauw, Brian Richard A1 - Gurlo, A. A1 - Simon, U. T1 - High specific surface area ordered mesoporous silica COK-12 with tailored pore size N2 - Ordered mesoporous silica materials such as COK-12, analogous to the well-known SBA-15, are characterized by high surface areas and unique features such as defined pore sizes in the meso-size range and high pore ordering. The aim of this work was to prove the washing step and choice of calcination and aging temperature during the COK-12 synthesis as effective tools in tailoring, markedly improving the specific surface area, pore size, and pore volume. By controlling the aging temperature, the pore size was linearly adjusted between 5.7 and 8.1 nm, while preserving the hexagonal ordering of the pores. The synthesized COK-12 powders possess pore volumes and specific surface areas up to 1.23 cm3 g−1 and 860m2 g−1, respectively, which is markedly higher than what has previously been reported about COK-12. The presented results and the environmentally friendly character of the synthesis will make COK-12 more interesting for future adaption to the industrial processes, for example in catalysis, adsorption, or drug delivery. KW - Ordered mesoporous silica KW - Pore size tailoring KW - High specific surface area KW - SAXS KW - Small angle scattering PY - 2019 DO - https://doi.org/10.1016/j.micromeso.2019.01.050 SN - 1387-1811 VL - 280 SP - 133 EP - 143 PB - Elsevier AN - OPUS4-47378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - You, Zengchao A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Weidner, Steffen T1 - Separation of polystyrene nanoparticles with different coatings using two-dimensional off-line coupling of asymmetrical flow field flow fractionation and capillary electrophoresis N2 - The successful off-line coupling of asymmetrical flow field flow fractionation (AF4) and capillary electrophoresis (CE) for separation of nanoparticles (NPs) with different surface coatings was shown. We could successfully demonstrate that, in a certain NP size range, hyphenation of both techniques significantly improved the separation of differently coated NPs. Three mixtures of polystyrene nanoparticles (PS-NPs) with comparable core sizes but different coatings (no coating/carboxyl-coated) were studied. Separation in either method resulted in non-baseline resolved or non-separated peaks. In contrast, two-dimensional off-line coupling of AF4 and CE resulted in clearly separated regions in their 2 D plots in case of 20 and 50 nm particle mixtures, whereas the 100 nm NP mixture could not be separated at all. Various factors affecting the separation like hydrodynamic diameter or SDS concentration were discussed. KW - Capillary electrophoresis (CE) KW - Nanoparticles with same nominal diameter KW - Surface coating KW - Two-dimensional off-line coupling KW - Asymmetrical flow field flow fractionation (AF4) PY - 2019 DO - https://doi.org/10.1016/j.chroma.2019.01.056 VL - 1593 SP - 119 EP - 126 PB - Elsevier AN - OPUS4-47363 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manso, M. A1 - Pessanha, S. A1 - Guerra, M. A1 - Reinholz, Uwe A1 - Afonso, C. A1 - Radtke, Martin A1 - Lourenco, H. A1 - Carvalho, M. L. A1 - de Oliveira Guilherme Buzanich, Ana T1 - Assessment of Toxic Metals and Hazardous Substances in Tattoo Inks Using Sy-XRF, AAS, and Raman Spectroscopy N2 - Synchrotron radiation X-ray fluorescence spectroscopy, in conjunction with atomic absorption and Raman spectroscopy, was used to analyze a set of top brand tattoo inks to investigate the presence of toxic elements and hazardous substances. The Cr, Cu, and Pb contents were found to be above the maximum allowed levels established by the Council of Europe through the resolution ResAP(2008)1 on requirements and criteria for the safety of tattoos and permanent makeup. Raman analysis has revealed the presence of a set of prohibited substances mentioned in ResAP(2008)1, among which are the pigments Blue 15, Green 7, and Violet 23. Other pigments that were identified in white, black, red, and yellow inks are the Pigment White 6, Carbon Black, Pigment Red 8, and a diazo yellow, respectively. The present results show the importance of regulating tattoo ink composition. KW - Synchrotron KW - Tattoo inks KW - XRF KW - Toxic metals KW - Hazardous substances PY - 2019 DO - https://doi.org/10.1007/s12011-018-1406-y VL - 187 IS - 2 SP - 596 EP - 601 PB - Springer AN - OPUS4-47369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - X-ray emission during ultrashort pulse laser processing N2 - The industrial use of ultrashort laser pulses has made considerable progress in recent years. The reasons for this lie in the availability of high average powers at pulse repetition rates in the several 100 kHz range. The advantages of using ultrashort laser pulses in terms of processing precision can thus be fully exploited. However, high laser intensities on the workpiece can also lead to the generation of unwanted X-rays. Even if the emitted X-ray dose per pulse is low, the accumulated X-ray dose can become significant for high-repetition-rate laser systems so that X-ray exposure safety limits must be considered. The X-ray emission during ultrashort pulse laser processing was investigated for a pulse duration of 925 fs at 1030 nm wavelength and 400 kHz repetition rate. Industrially relevant materials such as steel, aluminum and glass were treated. Tungsten served as reference. X-ray spectra were recorded, and X-ray dose measurements were performed for laser treatment in air. For laser intensities > 2 × 10^13 W/cm2, X-ray doses exceeding the regulatory exposure limits for members of the public were found. Suitable X-ray protection strategies are proposed. T2 - SPIE Photonics West CY - San Francisco, USA DA - 02.02.2019 KW - Laser-induced X-ray emission KW - Ultrashort laser material interaction KW - Radiation protection PY - 2019 AN - OPUS4-47361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit T1 - Quantitative biocide profile measurements by calibrated XPS N2 - This presentation provides an update on recent results from quantitative XPS-measurements of real and artificial biofilms. NAP-XPS, lab-based XPS and synchrotron-based XPS was used to obtain a vertical concentration profile of iodine in agarose-films with information depth ranging from 1 to 18 nm. T2 - Project meeting MetVBadBugs CY - Turin, Italy DA - 05.02.2019 KW - Biofilms KW - NAP-XPS KW - XPS KW - Iodine KW - Agarose PY - 2019 AN - OPUS4-47332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kittner, Maria T1 - Thermoanalytical methods for the optimisation of microplastic analysis in freshwater sediment samples N2 - Results of various thermoanalytical techniques are presented for the analysis of microplastics in sediment samples. The homogeneity and the representativness of samples war controlled, as well as steps of separation and microplastic detection by these techniques. T2 - MICRO CY - Lanzarote, Spain DA - 19.11.2018 KW - Water KW - Microplastics KW - Sampling KW - Sampling techniques PY - 2018 AN - OPUS4-47322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana T1 - Hard X-ray spectroscopy and imaging at the BAMline and MySpot beamlines at BESSY II (Berlin, Germany) N2 - Overview of the X-ray based analytical methods conducted at the BAMline and µSpot Beamline for structure analysis. T2 - Pccr2 + AfLS conference CY - Accra, Ghana DA - 29.01.2019 KW - X-ray spectroscopy KW - Synchrotron KW - Beamline KW - Material characterization PY - 2019 AN - OPUS4-47319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yusenko, Kirill T1 - BAMline 2.0 – further technical developments for a broader multipurpose hard X-ray beamline at BESSY II N2 - We show further development of our beamline in the contexst of further itermational collaboration. T2 - PACC and AfSC CY - Accra, Ghana DA - 28.01.2019 KW - Synchrotron radiation PY - 2019 AN - OPUS4-47317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Akbar, S. A1 - Hasanain, S.K. A1 - Ivashenko, O. A1 - Dutka, M.V. A1 - Akhtar, N. A1 - De Hosson, J.Th.M. A1 - Ali, Naveed A1 - Rudolf, P. T1 - Defect ferromagnetism in SnO2:Zn2+ hierarchical nanostructures: correlation between structural, electronic and magnetic properties N2 - We report on the ferromagnetism of Sn1-xZnxO2 (x < 0.1) hierarchical nanostructures with various morphologies synthesized by a solvothermal route. A room temperature ferromagnetic and paramagnetic response was observed for all compositions, with a maximum in ferromagnetism for x = 0.04. The ferromagnetic behaviour was found to correlate with the presence of zinc on substitutional Sn sites and with a low oxygen vacancy concentration in the samples. The morphology of the nanostructures varied with zinc concentration. The strongest ferromagnetic response was observed in nanostructures with well-formed shapes, having nanoneedles on their surfaces. These nanoneedles consist of (110) and (101) planes, which are understood to be important in stabilizing the ferromagnetic defects. At higher zinc concentration the nanostructures become eroded and agglomerated, a phenomenon accompanied with a strong decrease in their ferromagnetic response. The observed trends are explained in the light of recent computational studies that discuss the relative stability of ferromagnetic defects on various surfaces and the role of oxygen vacancies in degrading ferromagnetism via an increase in free electron concentration. KW - Ferromagnetism KW - Nanostructures KW - Magnetic properties PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473014 DO - https://doi.org/10.1039/c9ra00455f SN - 2046-2069 VL - 9 IS - 7 SP - 4082 EP - 4091 PB - Royal Society of Chemistry AN - OPUS4-47301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schoenhals, Andreas T1 - Structure property relationships of thin polymer films N2 - Polymers at interfaces play a major role in a broad variety of applications ranging from engineering purposes (for instance polymer based nanocomposites) to high tech implications (for instance light emitting diodes). Here, thin films with thicknesses down to few nanometers are prepared on different substrates as model systems for polymer composites. The thin films are investigated by a combination of surface analytical and volume sensitive methods. As surface analytical methods atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements (CAM) are employed. As volume sensitive broadband dielectric spectroscopy (BDS), specific heat spectroscopy (SHS), and ellipsometry are used. Especially attention is paid to understand the glass transition behavior of thin films because the glass transition is the key phenomenon determines the application of polymers also in thin films. To understand the glass transition behavior of thin films, which is controversially discussed in literature, a three layer model is discussed. Firstly, a mobile surface layer is assumed at polymer air interface of the film due to missing of segment/segment interactions. Secondly, in the middle of the film a bulk-like layer should be expected. Thirdly, for polymers having non-repulsive interactions with the substrate an irreversibly adsorbed layer is expected to be formed. Due the adsorption the molecular mobility of the segments in this layer is slowed down. What is measured for the glass transition of thin films is a complicated average of all of these effects. The different layers are hardly to address separately. Therefore, in the presentation especially model systems are selected and investigated to verify the layer model. T2 - Seminarvortrag Universität Dortmund CY - Dortmund, Germany DA - 29.01.2019 KW - Thin polymer films PY - 2019 AN - OPUS4-47289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor A1 - Sturm, Patrick A1 - Greiser, Sebastian A1 - Jäger, Christian A1 - Kühne, Hans-Carsten ED - Wang, J. ED - Kriven, W. ED - Fey, T. ED - Colombo, P. ED - Weber, W.J. ED - Amoroso, J. ED - Fahrenholtz, W.G. ED - Shimamura, K. ED - Halbig, M. ED - Kirihara, S. ED - Wu, Y. ED - Shurgart, K. T1 - One-part geopolymers and aluminosilicate gel-zeolite composites: factors influencing microstructure and engineering properties N2 - Mixing and curing of geopolymers and related alkali-activated materials without storage and handling of highly alkaline solutions possesses advantages regarding safety and economic viability. One possible approach is to produce these materials from solid silica feedstocks and solid sodium aluminate, and subsequent mixing with water. We present a comparison between geopolymers and aluminosilicate gel-zeolite composites synthesized by this route from different silica feedstocks (by-product silica from chlorosilane production, microsilica, rice husk ash) and with different SiO2/Al2O3 ratios, using results from XRD, NMR, SEM, thermal analysis, mechanical and acid resistance testing. The use of rice husk ash favors formation of a fully amorphous geopolymer with high strength. Utilization of the other silica feedstocks leads to formation of aluminosilicate gel-zeolite composites, the amount and kind of zeolites depending on the feedstock and the SiO2/Al2O3 ratio. These composites show beneficial dehydration behavior, viz. no distinct dehydration step of thermal strain, with the phase assemblage after heating to 1000°C controlled by the starting composition. Mortars produced from both, the geopolymers as well as the composites, exhibit high resistance to sulfuric acid attack, making them promising materials for the construction and the repair of industrial and sewer structures. T2 - 42nd International Conference on Advanced Ceramics and Composites CY - Daytona Beach, FL, USA DA - 21.01.2018 KW - Alkali-activated materials KW - One-part geopolymers KW - Sulfuric acid resistance KW - High-temperature resistance PY - 2019 DO - https://doi.org/10.1002/9781119543381.ch17 VL - 39 IS - 3 SP - 183 EP - 196 PB - John Wiley & Sons AN - OPUS4-47282 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - Early stages of high temperature oxidation/sulfidation studied by synchrotron x-ray diffraction and spectroscopy N2 - Ferritic high temperature alloys are widely used as boiler tube and heat exchanger materials in coal, biomass and co-fired power plants. All technologies have in common that the applied materials are exposed to different temperatures, process pressures and reactive atmospheres that lead to a change of the material properties and a further degradation of the material. Material changes caused by aging in highly corrosive and toxic gases such as SO2 are mainly studied ex situ after the reaction is finished. The solid material is deposited in the atmosphere for a certain period of time, and material changes are then examined by various microscopic techniques such as optical microscopy (OM), electron microprobe analysis (EMPA), scanning electron microscopy (SEM and TEM) and X-ray diffraction (XRD). Nevertheless, extensive efforts were made to study material changes of high temperature alloys under oxidizing and reducing atmospheres by environmental scanning electron microscopy or in situ TEM techniques However, the possibilities of microscopic in situ techniques are very limited for the use of highly corrosive and toxic gases such as SO2. Since Sulfur induced corrosion at temperatures relevant for coal and biomass fired power plants, which is causing breakaway oxidation and sulfide precipitation at grain boundaries, is still of scientific interest, the current work focuses on the effect of SO2 in an initial stage of corrosion of ferritic alloys. For the analysis of early stages of combined oxidation and sulphidation processes of Fe-Cr model alloys the usage of a light furnace to conduct a rapid reactive annealing experiment is feasible. Previous studies presented distinct results of the influence of chromium on early high temperature corrosion by SO2 by this technique and subsequent classical metallographic analyses. However, it is still not possible to trace the corrosion mechanism in real time by conducting single aging experiments. The current work introduces two different approaches to study the initial stages of high temperature oxidation processes by applying above state of the art X-ray diffraction and spectroscopy methods. One part focuses on the real time observation of the formation of corrosion products such as oxides and sulfides by energy dispersive X-ray diffraction (EDXRD). The potential of this technique to study crystallization and growth processes of thin films in a reactive environment in real time was previously shown for different compound semiconductors. This approach was now applied to follow oxidation and sulphidation processes of ferritic model alloys in SO2 and SO2/H2O environments. The diffraction signals of the X-rays were detected during the corrosion process and the peak area and positions were analyzed as a function of time. This procedure enables monitoring external oxide growth and material loss in real time in an early stage of corrosion. The other part of the current work presents the possibilities of X-ray absorption near edge structure spectroscopy (XANES) to characterize oxide scales and their growth mechanisms. Precise phase identification and quantification of corrosion products in a multi-phase oxide/sulfide scale is a pre-requisite to understand diffusion paths of metal ions and gas components. It is a challenging task to distinguish structurally similar reaction products such as Fe3O4 and FeCr2O4 especially in thin films with texture effects by diffraction. To illustrate for example Cr-out diffusion of an alloy throughout an inner and external oxide scale the differentiation of Fe3O4 and FeCr2O4 is indispensable. XANES uses the photoionization effect at the metal absorption edge in an aging product and accesses by this structural and chemical information. The current work uses XANES at the Fe-K and Cr-K absorption edge to identify various aging products grown as thin layers on alloys after short time aging experiments. A reaction chamber for combining high temperature oxidation experiments with surface sensitive X-ray absorption near edge structure spectroscopy will be introduced and first results of XANES on scales at high temperatures will be presented. T2 - ISHOC 2018 CY - Matsue, Japan DA - 22.10.2018 KW - Corrosion KW - Sulfidation KW - In situ KW - Diffraction KW - XANES PY - 2018 AN - OPUS4-47278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - High temperature oxidation/sulfidation meets X-ray absorption near edge structure spectroscopy (XANES) N2 - Ferritic-martensitic alloys with 12-16 % Cr in weight are subject to devices for various energy systems, such as coal power plants and waste incineration plants. These materials are exposed to a highly corrosive environment which lead to a degradation of the material. Especially the simultaneous oxidation and sulfidation is thereby of special interest. Proper spatially resolved measurements that determine not only chemical compositions but phases are rare. However, precise phase identification and quantification of corrosion products within the multi-phase corrosion scales is a key aspect to understand diffusion paths of metal ions and gas ions/molecules. This study investigated Fe-Cr model alloys with Cr contents from 0 to 13 % in weight in 0.5 % SO2 and 99.5 % Ar atmosphere to aim in a fundamental and systematic analysis. Samples were aged at 650 °C for time scales from 12 h to 250 h. The results presented here correspond to depth dependent phase identification of oxide and sulphide phases in the corrosion scales by using X-ray absorption near edge spectroscopy (XANES). Per sample a series of ca. 20 spots (1-5 µm spot size) from scale-gas to scale-metal interface were measured. XANES spectroscopy was performed at the Fe-K edge (7.11 keV) on polished cross sections. The collected spectra were fitted to a combination of reference materials to quantify the present phases at different positions within the scale.The phase distribution differs with Cr content and the Cr diffusion through pure Fe-oxide and mixed Fe-Cr-oxide phases is discussed. T2 - EFC Workshop "High Temperature Corrosion" CY - Frankfurt am Main, Germany DA - 26.09.2018 KW - High temperature corrosion KW - XANES PY - 2018 AN - OPUS4-47277 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - New insights in mechanochemical processes using real-time in situ investigations N2 - Use of synchrotron radiation for special sample conditions. Recent work of the group at BESSY II. T2 - DESY Usermeeting Satelite Workshop CY - Hamburg, Germany DA - 22.01.2019 KW - XRD KW - In situ KW - Rietveld KW - Synchrotron PY - 2019 AN - OPUS4-47262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - May the Force be with you - Mechanochemical syntheses studied in situ N2 - Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic, metal-organic, and inorganic compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms remain often unclear. In the last years, have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy. Here, we present an in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time. Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. T2 - Seminar Universität Montpellier CY - Montpellier, France DA - 24.01.2019 KW - Mechanochemistry KW - In situ PY - 2019 AN - OPUS4-47261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moldovan, R.-P. A1 - Wenzel, B. A1 - Teodoro, R. A1 - Neumann, W. A1 - Dukic-Stefanovic, S. A1 - Kraus, Werner A1 - Rong, P. A1 - Deuther-Conrad, W. A1 - Hey-Hawkins, E. A1 - Krügel, U. A1 - Brust, P. T1 - Studies towards the development of a PET radiotracer for imaging of the P2Y1 receptors in the brain: synthesis, 18F-labeling and preliminary biological evaluation N2 - Purine nucleotides such as ATP and ADP are important extracellular signaling molecules in almost all tissues activating various subtypes of purinoreceptors. In the brain, the P2Y1 receptor (P2Y1R) subtype mediates trophic functions like differentiation and proliferation, and modulates fast synaptic transmission, both suggested to be affected in diseases of the central nervous system. Research on P2Y1R is limited because suitable brain-penetrating P2Y1R-selective tracers are not yet available. Here, we describe the first efforts to develop an 18F-labeled PET tracer based on the structure of the highly affine and selective, non-nucleotidic P2Y1R allosteric modulator 1-(2-[2-(tert-butyl)phenoxy]pyridin-3-yl)-3- [4-(trifluoromethoxy)phenyl]urea (7). A small series of fluorinated compounds was developed by systematic modification of the p-(trifluoromethoxy)phenyl, the urea and the 2-pyridyl subunits of the lead compound 7. Additionally, the p-(trifluoromethoxy)phenyl subunit was substituted by carborane, a boron-rich cluster with potential applicability in boron neutron capture therapy (BNCT). By functional assays, the new fluorinated derivative 1-{2-[2-(tert-butyl)phenoxy]pyridin-3-yl}-3-[4-(2-fluoroethyl) phenyl]urea (18) was identified with a high P2Y1R antagonistic potency (IC50 ¼10 nM). Compound [18F] 18 was radiosynthesized by using tetra-n-butyl ammonium [18F]fluoride with high radiochemical purity, radiochemical yield and molar activities. Investigation of brain homogenates using hydrophilic interaction chromatography (HILIC) revealed [18F]fluoride as major radiometabolite. Although [18F]18 showed fast in vivo metabolization, the high potency and unique allosteric binding mode makes this class of compounds interesting for further optimizations and investigation of the theranostic potential as PET tracer and BNCT agent. KW - Purine P2Y1 receptors KW - Positron emission tomography KW - Brain PET tracers KW - Radiometabolites KW - Micellar chromatography KW - Hydrophilic interaction chromatography PY - 2019 DO - https://doi.org/10.1016/j.ejmech.2019.01.006 SN - 0223-5234 VL - 165 SP - 142 EP - 159 PB - Elsevier CY - Amsterdam AN - OPUS4-47253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tleuova, A. A1 - Schenderlein, Matthias A1 - Mutaliyeva, B. A1 - Aidarova, S. A1 - Sharipova, A. A1 - Bekturganova, N. A1 - Miller, R. A1 - Grigoriev, D. T1 - Selection and study of alkoxysilanes as loading in submicrocapsules for self-lubricating coatings N2 - The possibility and conditions for the formation of nano- or submicrocapsules loaded with hydrophobic active ingredients (alkoxysilanes) into the matrix of coatings with self-lubricating effect are considered. The optimal composition of the alkoxysilane submicrocapsules, and their physicochemical properties were determined. The longer the radical chain length is, the lower is the rate of hydrolysis, and, accordingly, the more stable is the formed emulsion. The methods of laser correlation spectroscopy in measuring the size and zeta potentials of the submicrocapsules with different loads of the active agent allowed to determine the optimal ratios of the active ingredients. The optimal concentration of the active agent is between 4 and 9%. Based on contact angle studies, octadecyltrimethoxysilane was selected as optimum compound. The introduction of 4 wt% of octadecyltrimethoxysilane reduces the friction coefficient of coatings by 20–30% under vibrating motion and by 15–20% under continuous motion. The data obtained can also be useful for the encapsulation of other hydrophobic active agents and for various other purposes, for example, for the introduction of biocidal agents. KW - Microencapsulation KW - Spontaneous emulsification KW - Self-lubricating coating KW - Antifriction coefficient KW - Alkoxysilanes PY - 2019 DO - https://doi.org/10.1016/j.colsurfa.2018.12.018 SN - 0927-7757 SN - 1873-4359 IS - 563 SP - 359 EP - 369 PB - Elsevier AN - OPUS4-47233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulow, Anicó A1 - Witte, S. A1 - Beyer, S. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, H. A1 - Streli, C. T1 - A new experimental setup for time- and laterally-resolved X-ray absorption fine structure spectroscopy in a 'single shot' N2 - In this work, a new setup for dispersive XAFS measurements is presented. This reproducible and scanningfree setup yields both time- and laterally-resolved XAFS experiments in a ‘single-shot’. It allows a straightforward adjustment for probing different elements covering many relevant applications in materials science. An incoming energetic broadband beam is diffracted by a Si (111) crystal after passing through the sample and collected by an area sensitive detector. Depending on the energy range of the incoming beam, XANES and/or EXAFS spectra can be recorded with a time resolution down to 1 s. The feasibility of this setup was demonstrated at the BAMline at BESSY II (Berlin, Germany) with reference Fe and Cu foils and the results are hereby presented and discussed. Additionally, an application where time resolution on the second scale is required is briefly evaluated. The presented example concerns studying early stages of zinc(II)2-methylimidazolate (ZIF-8) crystallization. This is particularly important for biomedical applications. KW - X-ray spectroscopy KW - X-ray absorption fine structure KW - Time-resolved KW - Laterally-resolved KW - Experimental setup PY - 2019 DO - https://doi.org/10.1039/c8ja00313k SN - 0267-9477 SN - 1364-5544 VL - 34 IS - 1 SP - 239 EP - 246 PB - Royal Society of Chemistry CY - London AN - OPUS4-47207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Crasselt, Claudia A1 - Schmidt, Wolfram A1 - Sturm, Heinz T1 - Influence of Rheology Modifying Admixtures on Hydration of Cementitious Suspensions N2 - The presence of polycarboxylate ether (PCE) based superplasticizers (SPs) has an enormous influence on the early hydration of cement. The hydration is retarded and the timing of formation and the morphology of hydrates is affected. This short paper presents experimental results about the influence of delayed addition time of PCE SPs on hydration of cement and alite pastes, investigated by isothermal heat flow calorimetry. For cement as well as for alite pastes the hydration is retarded with SP, whereby the high charge PCE has a stronger retarding effect than the low charge PCE. The retardation caused by PCE is much more pronounced for alite than for cement mixes. If PCE is added later to the mix, the induction period is shortened and the hydration is accelerated compared to simultaneous addition. This applies for cement and alite pastes. With delayed PCE addition the alite shows a clearly less retarded setting and main hydration than after simultaneous addition. It is obvious that for alite pastes there is less retardation the later the addition of SP. T2 - 6th International Symposium on Nanotechnology in Construction CY - Hong Kong, China DA - 02.12.2018 KW - Polycarboxylate ether (PCE) KW - Early hydration KW - Cement PY - 2018 SP - 1 EP - 8 AN - OPUS4-47204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bender, P. A1 - Fock, J. A1 - Hansen, M. F. A1 - Bogart, L. K. A1 - Southern, P. A1 - Ludwig, F. A1 - Wiekhorst, F. A1 - Szczerba, Wojciech A1 - Zeng, L. J. A1 - Heinke, D. A1 - Gehrke, N. A1 - Fernández Díaz, M. T. A1 - González-Alonso, D. A1 - Espeso, J. I. A1 - Rodríguez Fernández, J. A1 - Johansson, C. T1 - Influence of clustering on the magnetic N2 - Clustering of magnetic nanoparticles can drastically change their collective magnetic properties, which in turn may influence their performance in technological or biomedical applications. Here, we investigate a commercial colloidal dispersion (FeraSpinTMR), which contains dense clusters of iron oxide cores (mean size around 9 nm according to neutron diffraction) with varying cluster size (about 18–56 nm according to small angle x-ray diffraction), and its individual size fractions (FeraSpinTMXS, S, M, L, XL, XXL). The magnetic properties of the colloids were characterized by isothermal magnetization, as well as frequency-dependent optomagnetic and AC susceptibility measurements. From these measurements we derive the underlying moment and Relaxation frequency distributions, respectively. Analysis of the distributions shows that the clustering of the initially superparamagnetic cores leads to remanent magnetic moments within the large clusters. At frequencies below 105 rad s−1, the relaxation of the clusters is dominated by Brownian (rotation) relaxation. At higher frequencies, where Brownian relaxation is inhibited due to viscous friction, the clusters still show an appreciable magnetic relaxation due to internal moment relaxation within the clusters. As a result of the internal moment relaxation, the colloids with the large clusters (FSL, XL, XXL) excel in magnetic hyperthermia experiments. KW - Magnetic hyperthermia KW - Magnetic nanoparticles KW - Multi-core particles KW - Core-clusters PY - 2018 DO - https://doi.org/10.1088/1361-6528/aad67d VL - 29 IS - 42 SP - Articel 425705 PB - IOP Publishing CY - UK AN - OPUS4-47203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Bannick, C.G. A1 - Szewzyk, R. A1 - Ricking, M. A1 - Schniegler, S. A1 - Obermaier, N. A1 - Barthel, A. K. A1 - Altmann, Korinna A1 - Eisentraut, Paul T1 - Development and testing of a fractionated filtration for sampling of microplastics in water N2 - A harmonization of sampling, sample preparation and detection is pivotal in order to obtain comparable data on microplastics (MP) in the environment. This paper develops and proposes a suitable sampling concept for waterbodies that considers different plastic specific properties and influencing factors in the environment. Both artificial water including defined MP fractions and the discharge of a wastewater treatment plant were used to verify the derived sampling procedure, sample preparation and the subsequent analysis of MP using thermal extraction-desorption gas chromatography - mass spectrometry (TED-GC-MS). A major finding of this paper is that an application of various particle size classes greatly improves the practical handling of the sampling equipment. Size classes also enable the TED-GC-MS to provide any data on the MP size distribution, a substantial sampling property affecting both the necessary sampling volume and the optimal sampling depth. In the artificial water with defined MP fractions, the recovery rates ranged from 80 to 110%, depending on the different MP types and MP size classes. In the treated wastewater, we found both Polyethylene and polystyrene in different size classes and quantities. KW - Microplastics KW - Sampling KW - Sampling techniques KW - Water PY - 2019 DO - https://doi.org/10.1016/j.watres.2018.10.045 SN - 0043-1354 VL - 149 SP - 650 EP - 658 PB - Elsevier AN - OPUS4-47200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Separation of polystyrene nanoparticles with different coatings using 2D off-line coupling of asymmetrical flow field flow fractionation (AF4) and capillary electrophoresis (CE) N2 - Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important1,2. In this presentation, a two-dimensional separation approach based on AF4 and CE was showed and used to separate NPs with similar sizes but different coatings. Standard reference polystyrene NPs having comparable core sizes but different coatings were investigated. Different migration time and profiles were compared. Separation in either method resulted in non-baseline resolved or non-separated peaks. In contrast, two-dimensional coupling of AF4 and CE resulted in clearly separated regions in their 2 D plots in case of 20 and 50 nm particle mixtures, whereas the 100 nm NP mixture could not be separated. Various factors affecting the separation like hydrodynamic diameter or SDS concentration were discussed. Future investigations will be focussed on inorganic NPs with differently charged coatings. There, AF4-CE coupling can be coupled with inductively coupled plasma mass spectrometry (ICP-MS) to enhance the sensitivity of this method. T2 - 6th FFF-MS Tagung CY - Berlin, Germany DA - 22.11.2018 KW - Nanoparticles separation capillary electrophoresis asymmetrcial flow field flow fractionation PY - 2018 AN - OPUS4-47191 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Nanoparticles separation using capillary electrophoresis N2 - Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important. A common method for nanoparticle separation, which was introduced in 1976 by Giddings, represents asymmetrical field-flow fractionation (AF4). It is a flow based separation method, which can be theoretically used to separate particles range from 1 nm to 50 µm. However, when the particles are smaller than 10 nm, separation with AF4 will become difficult to perform. Because in this case strong separation force, which induces aggregation of particles, should be applied. This will decrease recoveries of analytes and limit its application in accurate quantitative analysis. Capillary electrophoresis (CE) is another well-developed separation technique, in which samples will be separated in relation to their electrophoretic mobility. In recent years, CE has been used to separate different kinds of nanoparticles like, gold colloids or CdSe Quantum dots. However, till now only separation of particles smaller than 50 nm was reported. Because large size distribution of bigger particles will result in strong peak broadening and long separation time. A two-dimensional coupling of AF4 and CE might provide us a new separation method, which can extend the separation ranges of both methods and be a way to characterise particles with large size distributions. T2 - ESAS-CANAS Konferenz CY - Berlin, Germany DA - 21.03.2018 KW - Nanoparticles separation capillary electrophoresis asymmetrcial flow field flow fractionation PY - 2018 AN - OPUS4-47188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Nanoparticles separation using capillary electrophoresis (CE) and asymmerical flow-field flow fractionation (AF4) N2 - Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important. A common method for nanoparticle separation, which was introduced in 1976 by Giddings, represents asymmetrical field-flow fractionation (AF4). It is a flow based separation method, which can be theoretically used to separate particles range from 1 nm to 50 µm. However, when the particles are smaller than 10 nm, separation with AF4 will become difficult to perform. Because in this case strong separation force, which induces aggregation of particles, should be applied. This will decrease recoveries of analytes and limit its application in accurate quantitative analysis. Capillary electrophoresis (CE) is another well-developed separation technique, in which samples will be separated in relation to their electrophoretic mobility. In recent years, CE has been used to separate different kinds of nanoparticles like, gold colloids or CdSe Quantum dots. However, till now only separation of particles smaller than 50 nm was reported. Because large size distribution of bigger particles will result in strong peak broadening and long separation time. A two-dimensional coupling of AF4 and CE might provide us a new separation method, which can extend the separation ranges of both methods and be a way to characterise particles with large size distributions. T2 - BAM PhD seminar CY - PhD seminar, Berlin, Germany DA - 22.06.2018 KW - Nanoparticles separation capillary electrophoresis asymmetrcial flow field flow fractionation PY - 2018 AN - OPUS4-47187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisentraut, Paul T1 - Turning up the heat: a thermoanalytical approach for the detection of microplastics N2 - The presentation deals with the analysis of plastics in environmental samples using the TED-GC-MS method. The method and its working principles are presented, method characteristics and application examples are given. Advantages and disadvantages compared to other methods are highlighted. T2 - Linnaeus Eco-Tech 2018 CY - Kalmar, Sweden DA - 19.11.2018 KW - Microplastics KW - Tire wear KW - Thermoanalysis KW - TED-GC-MS PY - 2018 AN - OPUS4-47185 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Detektion von Kunststoffen mittels TED-GC-MS N2 - Vortrag zur Funktionsweise der TED-GC-MS für die Analyse von Mikroplastik in Umweltproben T2 - Arbeitsgespräch der Ressortforschungseinrichtungen CY - Berlin, Germany DA - 26.11.2018 KW - Mikroplastik KW - TED-GC-MS PY - 2018 AN - OPUS4-47184 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Kunststoffe in der Umwelt: Elastomere, Thermoplaste und Duroplaste – worüber sprechen wir eigentlich und was sind die analytischen Herausforderungen? N2 - Übersichtsvortrag zur Thematik Kunststoffe in der Umwelt. Es werden Aspekte zu Definitionen, Eigenschaften und Analytischen Möglichkeiten und Herrausforderungen angesprochen. T2 - Arbeitsgespräch der Ressortforschungseinrichtungen CY - Berlin, Germany DA - 26.11.2018 KW - Mikroplastik KW - Umwelt KW - Polymere Eigenschaften PY - 2018 AN - OPUS4-47183 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Microplastics: Degradation properties of polymers in the environment N2 - The accumulation of plastics leaked into the environment achieve a high perception in the last years. It is uncontroversial that often an uncontrolled, high consumption of plastic products and a poor waste management resulted in plastic findings all over in the environment. However, less is known about the relevant pathways and fate of plastic in the environment. Especially plastic fragments smaller 5 mmm, so called microplastics, achieve a high attention, because their amount and risks arising from these fragments are still unknown. The basic mechanisms of plastic or more precise, of different polymer degradation processes are often not considered, resulting in unrealistic statements. For generation of fundamental understanding of this problem we developed in the last years a fast thermoanalytical method for identification and mass quantification of microplastics in complex samples. The presentation will also give a short introduction about polymer degradation. T2 - Environmental Geosciences Seminar CY - Vienna, Austria DA - 19.11.2018 KW - Microplastic KW - Analysis KW - Standardisation PY - 2018 AN - OPUS4-47182 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gaillard, C. A1 - Mech, A. A1 - Wohlleben, W. A1 - Babick, F. A1 - Hodoroaba, Vasile-Dan A1 - Ghanem, A. A1 - Weigel, S. A1 - Rauscher, H. T1 - A technique-driven materials categorisation scheme to support regulatory identification of nanomaterials N2 - Worldwide there is a variety of regulatory provisions addressing nanomaterials. The identification as nanomaterial in a regulatory context often has the consequence that specific legal rules apply. In identifying nanomaterials, and to find out whether nanomaterial-specific provisions apply, the external size of particles is globally used as a criterion. For legal certainty, its assessment for regulatory purposes should be based on measurements and methods that are robust, fit for the purpose and ready to be accepted by different stakeholders and authorities. This should help to assure the safety of nanomaterials and at the same time facilitate their international trading. Therefore, we propose a categorisation scheme which is driven by the capabilities of common characterisation techniques for particle size measurement. Categorising materials according to this scheme takes into account the particle properties that are most important for a determination of their size. The categorisation is exemplified for the specific particle number based size metric of the European Commission's recommendation on the definition of nanomaterial, but it is applicable to other metrics as well. Matching the performance profiles of the measurement techniques with the material property profiles (i) allows selecting the most appropriate size determination technique for every type of material considered, (ii) enables proper identification of nanomaterials, and (iii) has the potential to be accepted by regulators, industry and consumers alike. Having such a scheme in place would facilitate the regulatory assessment of nanomaterials in regional legislation as well as in international relations between different regulatory regions assuring the safe trade of nanomaterials. KW - Nanomaterial KW - Nanoparticles KW - Categorisation scheme KW - EC definition of a nanomaterial KW - Regulatory identification of nanomaterials PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471623 DO - https://doi.org/10.1039/C8NA00175H SN - 2516-0230 SP - 1 EP - 11 PB - The Royal Society of Chemistry AN - OPUS4-47162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Investigation of methanogen-induced microbiologically influenced corrosion under dynamic environments N2 - Microbially influenced corrosion (MIC) of iron is usually attributed to sulfate-reducing microorganisms (SRM) which act upon the metal by the reactiveness of hydrogen sulfide, and by withdrawal of the available electrons in electrical contact with the metal. Methanogenic archaea can also cause MIC by directly withdrawing electrons from the iron surface for methanogenesis. However, the mechanistic details and kinetics of the overall process are poorly understood. Precipitation of siderite, a by-product of methanogenesis, (4Fe + 5HCO3 + 5H+  4FeCO3 + CH4 + 3H2O) can lead to an insulating layer on the metal surface and lower the corrosion rate. Still, the extent of FeCO3 precipitation may be significantly influenced by environmental conditions such as pH and advective processes. T2 - IGD-TP Exchange Forum 8 CY - Berlin, Germany DA - 04.12.2048 KW - Archaea KW - Biocorrosion KW - MIC KW - Environmental Simulation PY - 2018 AN - OPUS4-47136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Schmidt, Wolfram A1 - Leinitz, Sarah A1 - Mota, Berta A1 - Crasselt, Claudia ED - Liu, Jiaping ED - Wang, Ziming ED - Holland, Terence ED - Huang, Jing ED - Plank, Johann T1 - Influence of the aqueous phase of cement paste on the rheology in the presence of PCE N2 - The paper presents rheometric results and hydration curves for cementitious systems based on cement mixed with different aqueous phases at solid volume fraction of  = 0.45. The varied aqueous phases were deionized water, limewater, the filter residue of a cement paste mixed at w/c = 2.0, and the filtrate of cement paste at solid volume fraction of 0.45. Each cementitious system provided different amounts and sizes of particles formed in the aqueous phase. The pastes were observed with and without polycarboxylate ether based superplasticizer. It was observed that the presence of particles causes higher PCE saturation dosages to achieve a minimum value, but the minimum value is only affected in the case of large particles. In all cases with and without PCE, the presence of small particles causes increased plastic viscosity. In addition, with decreased number and size of hydrates in the aqueous phase the hydration was retarded, which was specifically pronounced in the presence of PCE KW - Aqueous phase of cement paste KW - Polycarboxylate ether KW - Rheology KW - Yield stress KW - Plastic viscosity KW - Heat of hydration KW - Syngenite KW - Solid volume fraction PY - 2018 SN - 978-1-64195-029-9 SP - SP-329-34, 428 EP - 443 PB - American Concrete Institute CY - Farmington Hill, Michigan AN - OPUS4-47107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schenderlein, Matthias T1 - Monitoring early stage corrosion processes during biofilm formation N2 - To investigate early stage corrosion processes of stainless steel 1.4301 taking place during the biofilm formation of the organism Shewanella putrefaciens electrochemical impedance spectroscopy (EIS) in a multielectrode approach has been used. The multielectrode array consisted of up to 25 electrically isolated electrodes made of stainless steel wires of diameters ranging from 100 µm to 500 µm. They were connected to a multichannel microelectrode analyzer (MMA) electrically coupled through zero resistance ammeters. Current flow between electrodes in the array as well as changes in impedance of individual electrodes over time were recorded and analyzed with respect to the onset of localized corrosion and biofilm formation. The results were complemented by optical microscopy, SEM and AFM images which were taken immediately after the respective experiment. To verify that the multielectrode arrays correctly indicated the initial stages of the corrosion process and of biofilm formation they were introduced in a flow cell reaction vessel containing test specimens made from stainless steel 1.4301, which were checked regularly for signs of localized corrosion and biofilms. Preceding results with the multielectrode array in solutions containing high amounts of chloride ions and hydrogen peroxide at low pH also showed that it is possible with the MMA to monitor individual electrodes becoming local anodes as local corrosion set in, while the remaining electrodes predominantly acted as cathodes. T2 - 69th Annual Meeting of the International Society of Electrochemistry CY - Bologna, Italy DA - 02.09.2018 KW - Corrosion KW - Multielectrode KW - Biofilm KW - Monitoring KW - Stainless steel PY - 2018 AN - OPUS4-47095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Donskyi, Ievgen T1 - Gram-scale production of high quality nanographene under mild conditions and doping via non-destructive covalent functionalization N2 - We report a new method for top-down one-pot, gram-scale production of high-quality nanographene from graphite under mild conditions. The nanographene sheets had a very low oxygen content, comparable to that of nanographene grown by chemical vapor deposition. This method is easily scalable and comparatively mild, opening the door to an environmentally friendly process to produce high-quality nanographenes. Nanographene sheets were further covalently functionalized using a non-destructive [2+1] cycloaddition reaction that left the π-conjugated system intact. T2 - 10th Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Nano graphene KW - X-ray Photoelectron Spectroscopy (XPS) KW - NEXAFS KW - Raman spectroscopy PY - 2018 AN - OPUS4-47086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit T1 - Exploring the capabilities of NAP-XPS: Application to metal-organic frameworks, nanoparticles and biofilms N2 - Near-ambient pressure XPS makes it possible to characterise samples not compatible to ultra-high vacuum, and enables the study of liquid-solid, gas-liquid and gas-solid interfaces. NAP-XPS meas-urements of biofilms, suspended nanoparticles and metal-organic frameworks were performed with EnviroESCA developed by SPECS. An interesting application is surface characterisation of biofilms, which are bacterial communities embedded in a self-produced polysaccharide matrix. Various model systems ranging from pure polysaccharides of alginate to biofilms harvested directly from the growth medium have been char-acterised in humid conditions[1]. NAP-XPS also makes it possible to characterise nanoparticles in solution. Silver nanoparticles in aqueous solution were characterised and the Ag 3d-spectrum compared to spectra obtained of dried nanoparticles in UHV-conditions[2]. The binding energy of the Ag 3d-core level peak was shifted by 0,6 eV towards higher binding energy for suspended nanoparticles compared to the dried sample measured in UHV. This can be assigned to a change in surface potential at the water-nanoparticle interface. Metal-organic frameworks (MOFs) are suitable materials for gas storage of small molecules due to their nanoporous, crystalline structure. However, instability in humidity remains an issue for many types of MOFs. XPS-measurements of the MOF-structure HKUST-1 were performed in various NAP-conditions to assess the stability of the sample and its interaction with the gas molecules as water, methanol and pyridine. T2 - 5th AP-XPS Workshop CY - Berlin, Germany DA - 11.12.18 KW - Biofilms KW - E. coli KW - NAP-XPS KW - Metal organic frameworks KW - Nanoparticles PY - 2018 AN - OPUS4-47060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian T1 - Transformation of the antidiabetic drug metformin N2 - For years there have been more and more reports on the presence of drugs in the aquatic environment. Due to the demographic change, the consumption of pharmaceuticals has risen sharply. After taking the drugs, they are partly metabolized in the human body. However, the metabolism is not complete so that both the metabolites and non-metabolized amounts of the parent compounds are excreted. These compounds reach the waste water and afterwards the sewage treatment plants. In sewage treatment plants transformation products can be formed by the oxidative conditions during wastewater treatment processes. The transformation products may have a higher toxicity than the actual environmental pollutants and are often only partly removed during the waste water treatment. Since a lot of these compounds are still unknown, the transformation products are not detected by target analysis used in sewage treatment plants and are often released undetected in the aquatic ecosystems. The released substances may be subject to additional transformation processes in the environment. Pharmaceuticals produced in high amounts can be already detected in the μg/L range in water bodies worldwide. Metformin and its major transformation product guanylurea are one of the main representatives. Metformin is the drug of choice for treating type 2 diabetes. The drug therapy for diabetes mellitus has increased significantly in recent years. In the year 2015 1500 tons of metformin were prescribed in Germany (for statutory insured persons). Metformin is not metabolized in the human body and is excreted unchanged therefore concentrations between 57 μg/L and 129 μg/L are found in German waste water treatment plants influents. In this work the transformation of the antidiabetic drug metformin is investigated. The degradation of metformin is initialize by commercial water treatment techniques like UV-radiation or noncommercial techniques like heterogenous photocatalysis based on titanium dioxide. The degradation of metformin and resulting transformation products are analyzed by LC-MS/MS and LC-HRMS. T2 - SPEA 10 CY - Almeria, Spain DA - 04.06.2018 KW - Metformin KW - Photocatalysis PY - 2018 AN - OPUS4-47030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kricheldorf, H. R. T1 - Syntheses of Cyclic Polymers via the ROPPOC Approach N2 - Different strategies for the synthesis of polylactides were presented with special focus on Ring-opening Polymerization (ROP) and simultaneous ROP and Polycondensation (ROPPOC) mechanism. The mechanism of the formation of cyclic Polyesters is discussed in detail and established theories about the formation of cycles in polycondensation reactions are critically reviewed. T2 - DSM Competence Meeting CY - Dalfsen, The Netherlands DA - 12.11.2018 KW - Polylactide KW - MALDI-TOF mass spectrometry KW - Polycondensation KW - Cycles PY - 2018 AN - OPUS4-47027 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kabelitz, Anke T1 - In-situ characterisation of nucleation, growth, crystallisation and dissolution of nanoscaled iron oxides N2 - We present the synthesis of four mesoporous templated iron oxides: Ferrihydrite, Hematite, Maghemite, Magnetite/Maghemite and the influence of water on the crystallization mechanism and the kinetics. The absence of water stabilize the ferrihydrite structure. By monitoring the dissolution in situ by using a QCMB and ex situ microscopy we got details in the dissolution mechanism of ferrihydrite. T2 - Final Meeting of the CRC 1109 & Edith Flanigen Award Ceremony 2018 CY - Berlin, Germany DA - 10.10.2018 KW - Mesoporous KW - Iron oxide KW - Mechanism PY - 2018 AN - OPUS4-47010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kabelitz, Anke T1 - A02: In situ WAXS studies on the crystallization of Al 13 keggin clusters in water N2 - Polynuclear aluminium species (Al13 keggin cluster) find application in different areas like water purification [1], contaminant transport [2], and as pilling clays with high specific surface areas[3], due to their strong binding ability to aggregates and high positive charge. In the present contribution, we report on the in situ investigation of the Al13 sulfate synthesis by synchrotron wide-angle X-ray scattering (WAXS). Al13 cluster were crystallized by precipitating hydrolyzed aluminum solutions by the addition of sodium sulfate. The measurements were performed using a custom-made acoustic levitator as sample holder. The study provides information about the intermediates during the crystallization process. From the data, a mechanism was derived indicating the influence of the crystallization process. T2 - Final Meeting of the CRC 1109 & Edith Flanigen Award Ceremony 2018 CY - Berlin, Germany DA - 10.10.2018 KW - Crystallization KW - WAXS KW - Keggin Cluster PY - 2018 AN - OPUS4-47005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Andree, Stefan A1 - Heidmann, B. A1 - Bonse, Jörn A1 - Eylers, K. A1 - Ernst, O. A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Femtosecond laser-assisted fabrication of chalcopyrite micro-concentrator photovoltaics N2 - Micro-concentrator solar cells offer an attractive way to further enhance the efficiency of planar-cell technologies while saving absorber material. Here, two laser-based bottom-up processes for the fabrication of regular arrays of CuInSe2 and Cu(In,Ga)Se2 microabsorber islands are presented, namely one approach based on nucleation and one based on laser-induced forward transfer. Additionally, a procedure for processing these microabsorbers to functioning micro solar cells connected in parallel is demonstrated. The resulting cells show up to 2.9% efficiency and a significant efficiency enhancement under concentrated Illumination. KW - Chalcopyrite KW - Femtosecond laser patterning KW - Laser-induced forward transfer KW - Micro-concentrator solar cell KW - Photovoltaics PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-470026 DO - https://doi.org/10.3762/bjnano.9.281 SN - 2190-4286 VL - 9 SP - 3025 EP - 3038 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, M. AN - OPUS4-47002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Crasselt, Claudia T1 - Influence of rheology modifying admixtures on hydration of cementitious suspensions N2 - The state of fresh concrete is predominantly determined by the rheological properties of the cement paste. In order to control performance spectra and requirements of novel concretes and to better understand macroscopic phenomena, comprehensive knowledge of the material behavior of fresh cement suspensions as well as of the complex relationships of mechanisms at the nano and micro scale are necessary. This work focuses on micro and nano rheology of suspensions of cementitious model systems and the influence of polycarboxylate-based admixtures on the rheology. The phenomena are driven by multiple parameters such as adsorption and particle interactions. Hence, the first part examines the interaction between polycarboxylate ether (PCE) and synthesized clinker phases and hydration products as model systems with regard to early hydration products. T2 - 6th International Symposium on Nanotechnology in Construction CY - Hong Kong, China DA - 02.12.2018 KW - Cement KW - Early hydration KW - Polycarboxylate ether (PCE), PY - 2018 AN - OPUS4-46980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In-situ investigations of mechanochemical reactions N2 - Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic[1], metal-organic[2], and inorganic[3] compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms remain often unclear. In the last years, have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy.[4] Here, we present an in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time.[5] Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. T2 - ACS Conference Boston CY - Boston, USA DA - 19.08.2018 KW - Mechanochemistry KW - In situ KW - Kinetic PY - 2018 AN - OPUS4-46989 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - New insights in mechanochemical processes using real-time in situ investigations N2 - Mechanochemistry is increasingly used for synthesizing various materials including metal organic compounds and cocrystals. Although this synthesis approach offers a fast and pure synthesis in high yields, there is a lack in understanding the mechanisms of milling reactions. The necessary data can only be obtained in in situ experiments, which were only recently established for milling reactions. Herein, we present a novel setup enabling a combined in situ investigation of mechanochemical reactions using synchrotron XRD and Raman spectroscopy. T2 - ECM31 CY - Oviedo, Spain DA - 18.08.2018 KW - Mechanochemistry KW - In situ PY - 2018 AN - OPUS4-46990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical reactions N2 - Presentation of the recent results in the context of in situ investigations of reactions using X-ray diffraction. T2 - Germany Brazil Workshop: New light on mechanisms of chemical reactions CY - Kiel, Germany DA - 31.07.2018 KW - In situ KW - XRD PY - 2018 AN - OPUS4-46991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ studies of mechanochemistry: a force of synthesis N2 - Recent results in the field of mechanisms and kinetics of mechanochemical reactions. T2 - Seminar GFZ Potsdam CY - Postdam, Germany DA - 28.03.2018 KW - In situ KW - XRD KW - Rietveld PY - 2018 AN - OPUS4-46992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Synchrotron X-ray Investigations N2 - Summary of the techniques available at the BAMline and µspot BEamline. T2 - Workshop Humboldt University and Hebrew University of Jerusalem CY - Berlin, Germany DA - 09.10.2018 KW - In situ KW - XRD PY - 2018 AN - OPUS4-46993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - In situ investigation of mechanochemical syntheses of manganese phosphonates with N-containing ligands N2 - Mechanochemistry is a versatile approach for green and fast synthesis of pure substances. The exploration of the chemistry of metal phosphonates has gained considerable interest during the last decades due to their structural diversity. We synthesized manganese phosphonates in milling reactions. The mechanochemical reactions were investigated in situ to reveal the underlying mechanisms. T2 - Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - In situ KW - Thermography PY - 2018 AN - OPUS4-46999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - New insights in mechanochemical processes using real-time In situ investigations N2 - Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic[1], metal-organic[2], and inorganic[3] compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms remain often unclear. In the last years, have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy.[4] Here, we present an in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time.[5] Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. T2 - 5th International Conference "Fundamental Bases of Mechanochemical Technologies" CY - Novosibirsk, Russia DA - 25.06.2018 KW - Mechanochemistry KW - XRD KW - Kinetic KW - Coordination polymers PY - 2018 AN - OPUS4-46994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ characterization of nucleation, growth, crystallization and dissolution of nanoscaled iron oxides N2 - Nucleation and growths of iorn oxide nanoparticles studied in situ using XRD, XRF, SAXS and XANES. T2 - International CRC meeting CY - Berlin, Germany DA - 10.10.2018 KW - XRD KW - XANES PY - 2018 AN - OPUS4-46995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - Mechanochemical synthesis of metal phosphonates N2 - The exploration of metal phosphonates chemistry has gained great interest during the last decades, because of their structural diversity. Transition metal phosphonates are promising candidates for an application as electrocatalysts in oxygen evolution reactions (OER). Here, we present the in situ investigation of mechanochemical syntheses of different manganese phosphonates by synchrotron X-ray diffraction. Nitrilotri(methylenephosphonic acid) and N,N-Bis(phosphonomethyl)glycine were chosen as ligands. The liquid-assisted milling process can be divided into three steps, including an amorphous stage. One of the products has not been obtained by classical solution chemistry before. These metal phosphonates and/or their derivatives are considered to be active in electrochemical energy conversion. The verification of their applicability is one of the topics of our resent research. T2 - Fundamental Bases of Mechanochemical Technologies CY - Novosibirsk, Russia DA - 25.06.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - Thermography PY - 2018 AN - OPUS4-46996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Haferkamp, Sebastian T1 - In situ investigation of mechanochemical Knoevenagel condensations of benzaldehyde derivates N2 - Mechanochemistry is known for short reaction times, nearly quantitative conversions, and decreasing amount of solvents. Among organic syntheses, the Knoevenagel condensation is an important C-C bond forming reaction. We investigated the reaction of benzaldehyde derivates (nitro- and fluoro-derivates) with malononitrile syntheses by a combination of different in situ investigation techniques. T2 - BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Mechanochemistry KW - In situ PY - 2018 AN - OPUS4-46997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - In situ investigation of milling reactions and structure determination of the products using X-ray diffraction N2 - Mechanochemistry is a versatile approach for green and fast synthesis of pure substances. By milling the reactants, various organic, inorganic, and metal-organic compounds can be obtained in high yields. Although mechanochemistry is widely used, the underlying mechanisms are not fully understood making mechanochemical reactions difficult to predict. Metal phosphonates are metal-organic compounds accessible by grinding. Because of their structural diversity, the exploration of the chemistry of metal phosphonates has gained considerable interest during the last decades. Transition metal phosphonates are promising candidates for an application as electrocatalysts in oxygen evolution reaction (OER). Here, we present the in situ investigation of the mechanochemical synthesis of a manganese(II)-phosphonate by synchrotron X-ray diffraction and thermography. The product has not been obtained by classical solution chemistry before and its crystal structure was determined from PXRD data. The milling process can be divided into different steps, with the product crystallization corresponding with the highest temperature rise. The activity of this metal phosphonate towards OER was measured and is presented here. T2 - International School of Crystallography - 52nd Course: Quantum Crystallography CY - Erice, Italy DA - 1.06.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - OER KW - Thermography PY - 2018 AN - OPUS4-46998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria T1 - Real Time In Situ Study of Simvastatin Crystallization on Levitated Droplets N2 - In this contribution we describe an in-situ study of the crystallization of simvastatin in three solvents. The studies were carried out by solvent evaporation at the µSpot beamline using acoustically levitated solution droplets in combination with simultaneous X-ray diffraction, Raman spectroscopy, and imaging analysis. T2 - 10th Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Crystallization KW - Simvastatin KW - In-Situ Characterization PY - 2018 AN - OPUS4-46965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zietzschmann, F. A1 - Dittmar, S. A1 - Splettstößer, L. A1 - Hunsicker, J. A1 - Dittmann, Daniel A1 - Meinel, F. A1 - Rößler, A. A1 - Metzger, S. A1 - Jekel, M. A1 - Ruhl, A. S. T1 - Fast empirical lab method for performance projections of large-scale powdered activated carbon re-circulation plants N2 - Powdered activated carbon (PAC) for organic micro-pollutant (OMP) removal can be applied effectively on wastewater treatment plant (WWTP) effluents by using re-circulation schemes, accumulating the PAC in the system. This technique is complex because several factors are unknown: (i) the PAC concentration in the system, (ii) specific and average contact times of PAC particles, and (iii) PAC particle loadings with target compounds/competing water constituents. Thus, performance projections (e.g. in the lab) are very challenging. We sampled large-scale PAC plants with PAC sludge re-circulation on eight different WWTPs. The PAC plant-induced OMP removals were notably different, even when considering PAC concentrations in proportion to background organic sum parameters. The variability is likely caused by differing PAC products, varying water composition, differently effective plant/re-circulation operation, and variable biodegradation. Plant PAC samples and parts of the PAC plant influent samples were used in laboratory tests, applying multiples (0.5, 1, 2, 4) of the respective large-scale “fresh” PAC doses, and several fixed contact times (0.5, 1, 2, 4, 48 h). The aimwas to empirically identify suitable combinations of lab PAC dose (as multiples of the plant PAC dose) and contact time, which represent the PAC plant performances in removing OMPs (for specific OMPs at single locations, and for averages of different OMPs at all locations). E.g., for five well adsorbing, little biodegradable OMPs, plant performances can be projected by using a lab PAC dose of twice the respective full-scale PAC dose and 4 h lab contact time (standard deviation of 13 %-points). KW - Adsorption KW - Powdered activated carbon KW - Organic micro-pollutant KW - Trace organic contaminant PY - 2019 DO - https://doi.org/10.1016/j.chemosphere.2018.10.055 VL - 215 SP - 563 EP - 573 PB - Elsevier Ltd. AN - OPUS4-46957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Panne, Ulrich T1 - "Keine Dienstmagd" - Analytical Sciences in Action N2 - Analytical Sciences has developed from Ostwald’s “unentbehrlichen Dienstmagd” to a chemical discipline at the core of many of today’s fundamental and applied scientific problems and innovations. An atomic or molecular understanding of basic processes in chemistry, soft matter physics, materials and life science is enabled only through new analytical methods and instrumentation. Similar observations can be found for pressing sociopolitical conflicts of the future: A rational discussion of global climate change or new energy sources is only possible with reliable analytical results. Progress in Analytical Sciences is only possible if the underlying interdisciplinary character is acknowledged and valued. The talk will illustrate the scope of modern Analytical Science through examples from process analysis relevant to modern process intensification and industry 4.0 to bioanalysis and the use of synchrotron radiation to elucidate fundamental reactions materials. T2 - MChG Talk CY - Technische Universität München, Germany DA - 27.11.2018 KW - Analytical Sciences PY - 2018 AN - OPUS4-46940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit T1 - Depth-dependent analysis of model biofilms by combining laboratory- and synchrotron-based X-ray photoelectron spectroscopy N2 - Synchrotron XPS in the soft-X-ray regime is suitable for the detection of light elements commonly found in biological samples. Various model systems of biofilms have been developed and characterised at synchrotron- and lab-based facilities. By obtaining the chemical composition at various information depths, the vertical distribution of iodine in an artificial biofilm have been determined. T2 - Tenth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Biofilms KW - HAXPES KW - XPS KW - Iodine KW - Synchrotron-XPS PY - 2018 AN - OPUS4-46929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Greiser, Sebastian A1 - Gluth, Gregor A1 - Sturm, Patrick A1 - Jäger, Christian T1 - 29Si{27Al}, 27Al{29Si} and 27Al{1H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel-zeolite composites N2 - The influence of starting materials and synthesis route on the properties and the structure of cementitious sodium aluminosilicate gels is not fully understood, partly due their amorphous nature and the fact that they often contain residual reactants, which can make the results of single-pulse NMR spectroscopy applied to these materials difficult to interpret or ambiguous. To overcome some of these limitations, 29Si{27Al} TRAPDOR NMR as well as 27Al{29Si} and 27Al{1H} REDOR NMR spectroscopy were applied to materials synthesized by the one-part alkali-activation route from three different amorphous silica starting materials, including rice husk ash. The latter led to formation of a fully amorphous sodium aluminosilicate gel (geopolymer), while the materials produced from the other silicas contained amorphous phase and crystalline zeolites. Application of the double-resonance NMR methods allowed to identify hydrous alumina gel domains in the rice husk ash-based material as well as significantly differing amounts of residual silica in the three cured materials. Four-coordinated Al existed not only in the aluminosilicate gel framework but also in a water-rich chemical environment with only a small amount of Si in proximity, likely in the alumina gel or possibly present as extra-framework Al in the aluminosilicate gel. The results demonstrate how the employment of different silica starting materials determines the phase assemblage of one-part alkali-activated materials, which in turn influences their engineering properties such as the resistance against chemically/biologically aggressive media. KW - Alkali-activated materials KW - Solid-state NMR KW - Aluminium hydroxide KW - Rice husk ash PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-469353 DO - https://doi.org/10.1039/C8RA09246J SN - 2046-2069 VL - 8 IS - 70 SP - 40164 EP - 40171 PB - Royal Society of Chemistry AN - OPUS4-46935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Simoes, R. A1 - Bernades, C. A1 - Joseph, A. A1 - Piedade, F. A1 - Kraus, Werner A1 - Emmerling, Franziska A1 - Diogo, H. A1 - da Piedade, M. T1 - Polymorphism in simvastatin: Twinning, disorder, and enantiotropic phase transitions N2 - : Simvastatin is one of the most widely used active pharmaceutical ingredients for the treatment of hyperlipidemias. Because the compound is employed as a solid in drug formulations, particular attention should be given to the characterization of different polymorphs, their stability domains, and the nature of the phase transitions that relate them. In this work, the phase transitions delimiting the stability domains of three previously reported simvastatin forms were investigated from structural, energetics, and dynamical points of view based on single crystal X-ray diffraction (SCXRD), hot stage microscopy (HSM), and differential scanning calorimetry (DSC) experiments (conventional scans and heat capacity measurements), complemented with molecular dynamics (MD) simulations. Previous assignments of the crystal forms were confirmed by SCXRD: forms I and II were found to be orthorhombic (P212121, Z′/Z = 1/4) and form III was monoclinic (P21, Z′/Z = 2/4). The obtained results further indicated that (i) the transitions between different forms are observed at 235.9 ± 0.1 K (form III → form II) and at 275.2 ± 0.2 K (form II → form I) in DSC runs carried out at 10 K min−1 and close to these values when other types of techniques are used (e.g., HSM). (ii) They are enantiotropic (i.e., there is a transition temperature relating the two phases before fusion at which the stability order is reversed), fast, reversible, with very little hysteresis between heating and cooling modes, and occur under single crystal to single crystal conditions. (iii) A nucleation and growth mechanism seems to be followed since HSM experiments on single crystals evidenced the propagation of an interface, accompanied by a change of birefringence and crystal contraction or expansion (more subtle in the case of form III → form II), when the phase transitions are triggered. (iv) Consistent with the reversible and small hysteresis nature of the phase transitions, the SCXRD results indicated that the molecular packing is very similar in all forms and the main structural differences are associated with conformational changes of the “ester tail”. (v) The MD simulations further suggested that the tail is essentially “frozen” in two conformations below the III → II transition temperature, becomes progressively less hindered throughout the stability domain of form II, and acquires a large conformational freedom above the II → I transition. Finally, the fact that these transitions were found to be fast and reversible suggests that polymorphism is unlikely to be a problem for pharmaceutical formulations employing crystalline simvastatin because, if present, the III and II forms will readily convert to form I at ambient temperature. KW - Polymorphism KW - Twinning KW - Disorder KW - Simvastatine PY - 2018 DO - https://doi.org/10.1021/acs.molpharmaceut.8b00818 SN - 1543-8384 SN - 1543-8392 VL - 15 IS - 11 SP - 5349 EP - 5360 PB - American Chemical Society CY - Washington, DC AN - OPUS4-46927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas T1 - Broadband dielectric spectroscopy to study soft matter systems N2 - The basics of broadband dielectric spectroscopy were introduced in detail. The analysis of the data was discussed. As application of broadband dielectric spectroscopy the alpha-relaxation (dynamic glass transition) and the chain dynamics of polymers were ilustrated. Further the application of dielectric spectroscopy to polymerbased nanocomposites and high preformance polymers was discussed in detail. T2 - Kolloquiumsvotrag am Karlsruher Instiut of Technology CY - Karlsruhe, Germany DA - 05.12.2018 KW - Broadband dielectric spectroscopy PY - 2018 AN - OPUS4-46910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Breitfeld, Steffen T1 - BaF-Coordination polymers: Mechanochemical syntheses of new coordination polymers with a direct Ba-F bond N2 - Metal organic frameworks (MOFs) and coordination polymers (CPs) Play an important role in different fields of applications like e.g. catalysis, separations, gas storages, sensors or optoelectronics. Moreover, particularly fluorinated metal-organic frameworks (FMOFs) are in the focus of interest during the last years. Due to the strong electronegativity of fluorine the FMOFs show beside an enhanced thermal stability excellent optical and electrical properties compared to non-fluorinated frameworks. In most cases fluorine is implemented using perfluorinated organic linkers at the synthesis, usually performed by solvothermal synthesis. However, only few examples are known so far where fluorine is coordinated directly to the metal cation. Recently we reported about successful mechanochemical syntheses and characterization of fluorine-containing coordination polymers of alkaline earth metals by milling M(OH)2 (M: Ca, Sr, Ba) with fluorinated benzene dicarboxylic acids. In the present study, it was shown that it is possible to connect fluorine directly to Barium using a mechanochemical synthesis route. A new phase pure barium coordination polymer, BaF-benzene-dicarboxylate (BaF(p-BDC)0.5), was synthesized by milling starting either from barium hydroxide or from barium acetate as sources for barium cations. In both cases the second reactant was 1,4-benzenedicarboxylic acid (H2(p-BDC)). Ammonium fluoride was used as fluorinating agent directly at milling. Although single crystals are not accessible so far and the structure was not solved yet, both the 19F MAS NMR spectrum and the FT IR spectrum give strong evidence that fluorine as well as 1,4-benzenedicarboxylate are connected to barium. This is the first mechanochemical synthesis of coordination polymers where fluorine is directly coordinated to the metal cation. The new compound BaF(p-BDC)0.5 was characterized by X-ray powder diffraction, FT IR- and 19F, 1H-13C CP MAS NMR spectroscopies, DTA-TG and elemental analysis. T2 - Konferenz CY - Oberjoch, Germany DA - 22.07.20108 KW - Mechanochemical syntheses KW - Coordination polymers KW - Direct fluorine-metal bond KW - Alkaline earth metal PY - 2018 AN - OPUS4-46897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Tumanov, N. A1 - Tumanova, N. A1 - Fischer, Franziska A1 - Morelle, F. A1 - Ban, V. A1 - Robeyns, K. A1 - Filinchuk, Y. A1 - Wouters, J. A1 - Leyssens, T. T1 - Exploring polymorphism and stoichiometric diversity in naproxen/proline cocrystals N2 - We present naproxen/proline cocrystals discovered when combining enantiopure and racemic naproxen and proline. Using liquid-assisted grinding as the main method to explore the variety of crystal forms in this system, we found 17 cocrystals, of which the structures of only four of them were previously known. The naproxen/proline system exhibited multiple polymorphs of 1 : 1 stoichiometry as well as more rare cocrystals with 1 : 2 and 2 : 3 stoichiometries, two cocrystal hydrates and one cocrystal solvate. In situ ballmilling, used to monitor liquid-assisted grinding reactions, revealed that the solvent dictates the reaction intermediates even if the final reaction product stays the same. Synchrotron X-ray diffraction data collected in situ upon heating allowed us to monitor directly the phase changes upon heating and gave access to pure diffraction patterns of several cocrystals, thus enabling their structure determination from powder X-ray diffraction data; this method also confirmed the formation of a conglomerate in the RS-naproxen/DL-proline system. Proline in cocrystals kept its ability to form charge-assisted head-to-tail N-H⋯O hydrogen bonds, typical of pure crystalline amino acids, thus increasing the percentage of strong chargeassisted interactions in the structure and consequently providing some of the cocrystals with higher melting points as compared to pure naproxen. The majority of drugs are chiral, and hence, these data are of importance to the pharmaceutical industry as they provide insight into the challenges of chiral cocrystallization. KW - In situ KW - Mechanochemistry KW - XRD PY - 2018 UR - https://pubs.rsc.org/en/Content/ArticleLanding/CE/2018/C8CE01338A#!divAbstract DO - https://doi.org/10.1039/c8ce01338a SN - 1466-8033 VL - 20 IS - 45 SP - 7308 EP - 7321 PB - Royal Society of Chemistry CY - London AN - OPUS4-46913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chapartegui, Ander T1 - MOFs as optical sensor elements against endocrine disrupting phthalates N2 - The development of optical sensing technologies for Endocrine Disrupting Chemicals (EDCs) was urgently needed to facilitate currently unmet demands on comprehensive monitoring of These substances, thus ensuring consumer safety. T2 - SALSA CY - Berlin, Germany DA - 01.05.2018 KW - MOF KW - Short chained phthalates PY - 2018 AN - OPUS4-46889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chapartegui, Ander T1 - Metal-Organic Frameworks as turn on fluorescent optical sensors against endocrine disrupting phthalate plasticizers N2 - The development of quick and simple optical sensing technologies for Endocrine Disrupting Chemicals (EDCs) is needed to facilitate monitoring of these substances to ensure consumer safety. Optical sensing was achieved against phthalates acting as EDC that have host guest interaction with an intercalated Metal-organic framework (MOF), resulting in a fluorescence emission upon excitation. The fluorescent turn-on signal was generated by using a fluorophore with a structural component that has little fluorescence unless excimers are formed. Strategies to engineer functional MOF structures suitable for sensing EDC phthalates were developed, and the characterization of the MOFs with and without present phthalates was done by single crystal XRD, PXRD, RAMAN and Thermogravimetry. Extensive photo-physical characterization of host-guest complexes of different phthalates and the MOF as well as the resulting exciplex fluorescence was performed. Photo physical characterization revealed an analyte specific fluorescence fingerprint that allows discerning even minute changes in chemical structures of the analyte and therefore paving the way for sensing tools in real world analytical applications. The presented capability of MOFs to sense EDCs is envisioned to complement established methods from analytical chemistry such as mass spectrometry based methods which can’t be used on site and are often associated with infrastructural capacity constraints T2 - EURoptrode CY - Naples, Italy DA - 25.03.2018 KW - MOF KW - Short chained Phthalates PY - 2018 AN - OPUS4-46890 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobol, Oded T1 - BAM’s role in materials science and hydrogen in metals: TOF-SIMS imaging N2 - Due to its low mass and high diffusivity in presence of compositional, thermal and mechanical gradients, hydrogen within a metallic microstructure can result in severe loss in ductility even at low concentrations and might lead eventually to a catastrophic and unpredictable failure of structural components during service. In this context, hydrogen mapping at the microscale is still considered among the most important challenges on the pathway towards a better understanding of the hydrogen transport and assisted cracking phenomena in metals, specifically in structural components, e.g. steels. Among the very few available techniques to localize hydrogen at the microscale, Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was proven to be a reliable tool. Based on the assumption that deuterium influence the microstructure similarly to hydrogen, in the following contribution ToF-SIMS was applied as the main technique to detect and locally map the deuterium distribution in several alloys: lean 2101 and standard 2205 duplex stainless steel (DSS), AISI 304L austenitic stainless steel and titanium 6Al-4V alloy. These alloys were selected as case studies in this work due to the wide use of them in many applications and environments which frequently provide critical conditions for hydrogen absorption and assisted degradation. The innovative design of in-situ and ex-situ experiments enabled us to elucidate the permeation, transport and trapping of deuterium in the microstructure in sub-micron resolution for the first time. In addition to the novel experimental setups, further progress was gained by applying computational multivariate data analysis (MVA) on the raw data and data fusion with high resolution structural characterization methods (scanning electron microscopy and electron back-scattered diffraction – SEM/EBSD). This combination allowed us to correlate the deuterium distribution and the influence on the microstructure. T2 - 4th Symposium on Innovative Measurement and Analysis for Structural Materials CY - Tokyo, Japan DA - 13.11.2018 KW - ToF-SIMS KW - Duplex stainless steel KW - Austenitic stainless steel KW - Principal Component Analysis KW - Data-fusion PY - 2018 UR - https://unit.aist.go.jp/tia-co/project/SIP-IMASM/sympo/2018/index.html AN - OPUS4-46867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobol, Oded T1 - Hydrogen assisted cracking phenomena in duplex stainless steels elucidated by in- and ex-situ ToF-SIMS experiments N2 - In the presented research, the high potential and abilities of secondary ion mass spectrometry (ToF-SIMS) to detect and locally map the hydrogen distribution in two types of duplex stainless steels are shown. The research validates certain proposed mechanisms by combining ToF-SIMS with high-resolution scanning electron microscopy and electron-backscattered diffraction. The combination of data from several techniques on the same region was conducted in this field for the first time by applying data treatment of the ToF-SIMS raw data and data fusion approach. This powerful combination of methods allows reviewing of the occurring processes related to hydrogen assisted cracking. The step beyond the state of the art in this field was gained here by developing permeation and mechanical loading experiments within the ToF-SIMS during chemometric imaging of the hydrogen distribution in the microstructure. The research presents the necessary correlation between the hydrogen distribution and the resulted structural changes, the diffusion behavior in a duplex microstructure and stress induced diffusion of hydrogen by applying external load at the microscale. T2 - 6th WMRIF Early Career Scientist Summit CY - NPL Teddington UK DA - 18.06.2018 KW - ToF-SIMS KW - Duplex stainless steel KW - LDX KW - EBSD KW - Data-fusion PY - 2018 AN - OPUS4-46865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Sekundärstrahlungsemission bei der UKP-Laser-Anwendung: Herausforderung für die Arbeitssicherheit N2 - Im Vortrag werden die Risiken, insbesondere die unerwünschte Erzeugung von Röntgenstrahlung, bei der Nutzung ultrakurzer Laserimpulse in der Materialbearbeitung beschrieben. Neue Anforderungen an den Arbeitsschutz werden dargestellt. T2 - SPECTARIS, Deutscher Industrieverband für optische, medizinische und mechatronische Technologien e.V., Veranstaltung Technische Kommission Photonik CY - Berlin, Germany DA - 27.11.2018 KW - Ultrakurze Laserimpulse KW - Materialbearbeitung KW - Röntgenstrahlung KW - Arbeitsschutz PY - 2018 AN - OPUS4-46859 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Femtosecond laser-assisted photovoltaic bottom-up strategies N2 - A promising technology in photovoltaics is based on micro-concentrator solar cells, where the photovoltaic active area is realized as an array of sub-millimeter sized thin-film solar cells. Different approaches to produce micro-sized precursors of CIGSe absorbers on molybdenum are presented using 30-fs laser pulses at 790 nm wavelength. On the one hand, a multi pulse surface structuring of the molybdenum or the underlying glass substrate and a subsequent physical vapor deposition (PVD) process were used for a site-selective aggregation of indium droplets. On the other hand, a single pulse laser-induced forward transfer (LIFT) was utilized to selectively deposit combined copper/indium/gallium precursor pixels on the molybdenum back contact of the solar cell. It was demonstrated that a postprocessing of the laser-generated micro-sized precursors results in an array of working CIGSe solar cells with an efficiency of 2.9% for 1 sun Illumination. T2 - Leibniz-Institut für Oberflächenmodifizierung (IOM), Institutskolloquium CY - Leipzig, Germany DA - 29.11.2018 KW - Femtosecond laser patterning KW - Laser-induced forward transfer KW - CIGSe KW - Micro solar cell KW - Light concentration PY - 2018 AN - OPUS4-46831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Lippitz, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Schmid, Thomas A1 - Heinrich, Hans-Joachim A1 - Recknagel, Sebastian A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Zirconium permanent modifiers for graphite furnaces used in absorption spectrometry: understanding their structure and mechanism of action N2 - The mechanism of action of zirconium permanent modifiers on graphite surfaces was investigated in order to understand its influence on the analytical signal in atomic and molecular absorption spectrometry (AAS/MAS). For this, the molecule formation of CaF was studied, which is used for the indirect analytical determination of fluorine in high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). The kinetics of this reaction was established by monitoring its molecular spectrum at different atomisation temperatures. An Arrhenius plot showed a pseudo-first order reaction with respect to fluorine (n = 1). An intermediate state was isolated, and its structure was elucidated by spectroscopic methods: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEMEDX), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES and EXAFS), and Raman microspectroscopy. We propose here a mechanism, where ZrO2 acts as a heterogeneous catalyst: after a pyrolytic step, an intermediate state of ZrO(OCaF) is activated, and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. No evidence of the formation of zirconium carbide was found. Consequently, as the CaF formation is catalysed by a heterogeneous catalyst, surface modifications with ZrO2 nanoparticles and ZrO xerogels were investigated in order to increase the surface area. Their influence was evaluated in the molecule formation of CaF, CaCl, CaBr, and CaI. Graphite furnace modification with zirconium oxide nanoparticles proves to be the best choice for fluorine analysis with a signal enhancement of more than eleven times with respect a non-coated graphite furnace. However, the influence of zirconium modifications in the analytical signals of Cl, and I is lower than the F signals or even negative in case of the Br. Understanding zirconium modifiers as heterogeneous catalysts offers a new perspective to AAS and MAS, and reveals the potential of surface analytical methods for development of improved permanent modifiers and graphite furnace coatings. KW - Zirconium KW - HR-CS-MAS KW - Graphite furnace KW - Nanoparticles KW - Xerogel KW - Calcium monofluoride KW - Absorption spectrometry PY - 2018 UR - https://pubs.rsc.org/en/content/articlelanding/2018/ja/c8ja00190a DO - https://doi.org/10.1039/C8JA00190A SN - 0267-9477 VL - 33 IS - 12 SP - 2034 EP - 2042 PB - Royal Society of Chemistry AN - OPUS4-46775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanistic investigations of mechanosyntheses N2 - Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic, metal-organic, and inorganic compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms often remain unclear. In the last years, we have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy. A further development is the in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time. [5] Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. Based on these data, metastable polymorphs of cocrystals and coordination polymorphs could be isolated and struc-turally characterized. A multi-step diffusion mechanism was identified for most systems. Crystalline phases were obtained intermediately, suggesting that the synthesis is following Ostwald’s rules of stages. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. T2 - Beilstein Symposium MECHANOCHEMISTRY: MICROSCOPIC AND MACROSCOPIC ASPECTS CY - Rüdesheim, Germany DA - 13.11.2018 KW - Mechanochemistry KW - Phosphonates KW - In situ PY - 2018 AN - OPUS4-46758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinrich, Thomas T1 - BAM and Division 6.1 N2 - This is a short overview of BAM and Division 6.1. We have insight into BAM's roles and responsibilities and the work we are doing in Division 6.1. T2 - Visit at CSEM Landquart CY - Landquart, Switzerland DA - 13.08.2018 KW - ToF-SIMS KW - AES KW - XPS KW - SEM PY - 2018 AN - OPUS4-46765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kunz, Valentin T1 - How to meet new challenges in advanced nanoparticle analytics N2 - Three current research projects performed at BAM’s Division for Surface Analysis and Interfacial Chemistry are presented that tackle important challenges with regard to the characterization of nanomaterials: 1) The characterization at ambient pressure, 2) the investigation of core-shell nanoparticles, and 3) the characterization of non-spherical particles by electron microscopy. 1) Surface analytical techniques such as Photoelectron Spectroscopy (XPS) or Secondary Ion Mass Spectrometry (SIMS) typically require measurements in ultra-high vacuum. However, for many applications (e.g. catalysis and nanotoxicology) it is important to know the surface chemical properties of nanomaterials at ambient conditions. Therefore, near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) was used to investigate nanoparticles in suspension. The used instrumental set-up allows to directly insert nanoparticle suspensions into the analysis chamber and to measure without prior sample preparation. Compared to dry reference samples measured under high-vacuum, a shift towards higher binding energies was observed for silver nanoparticles in water, indicating a change of surface potential at the water-nanoparticle interface. 2) To determine the dimensions of core-shell nanoparticles (shell thickness, core and total diameter), scanning transmission X-ray microscopy (STXM) was used. The analyzed model system consists of a polytetrafluorethylene (PTFE) core surrounded by a polystyrene (PS) shell, providing a strong X-ray absorption contrast at the C K-edge and a well-defined interface. The introduced STXM‐based methodology yields particle dimensions in agreement with scanning electron microscopy (SEM) results and provides additional information such as the position of the particle core, which cannot be extracted from a SEM micrograph. 3) The accurate measurement of size distributions of non-spherically shaped nanoparticles (representing most of the industrial nanoparticulate materials) is a challenging analytical task. High-resolution electron microscopy (TEM and SEM) is best suited to access the shape of individual nanoparticles. To fill the gap between ideal, monodisperse particles of spherical shape and complex real-world samples, BAM has started the work to develop reference nanoparticles of controlled shape, such as TiO2 platelets, bipyramids, and elongated particles. Results of a recent ISO inter-laboratory comparison will be shown with emphasis on the measurement parameters, descriptors and data analysis. T2 - NanoSafe Conference 2018 CY - Grenoble, France DA - 5.11.2018 KW - Nanoparticles PY - 2018 AN - OPUS4-46730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René T1 - Multi-method analysis of pore-controlled mesoporous oxide materials N2 - Determining the porosity of catalytic layers is crucial for quality assurance. We present results of a multi-method study to determine thickness, porosity, dielectric function and other properties of pure and mixed iridium and titanium oxide layers used in electrocatalytic water splitting. T2 - European Optical Society Biennial Meeting (EOSAM) 2018 CY - Delft, The Netherlands DA - 08.10.2018 KW - Multi-method analysis KW - Mesoporous oxide materials KW - Electro catalytic water splitting KW - Electron probe X-ray microanalysis (EPMA) KW - Spectroscopic ellipsometry (SE) KW - Optical porosimetry PY - 2018 AN - OPUS4-46740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Freshwater compartments: Screening method for polymer identification and mass contents of microplastic particles using TED-GC-MS N2 - The pathways of plastics, especially of microplastic (MP), in environmental compartments, particularly in aquatic systems, are not well understood. The critical point is the lack of fast, harmonised methods for sampling, sample preparation and sample analysis. These three analytical steps are dependent on one another and must be optimised. In recent years, we developed a method for representative sampling and fast detection of MP in aqueous systems. The sampling in different freshwater bodies is performed in the field with a fractionated filtration system using mesh sizes of 500, 100 and 50 µm. For water with an intermediate or high content of suspended particular matter a minimum of 1000 L has to be filtered. In the lab, mesh sizes of 10 and 5 µm are used for further filtration. Subsequently, the water filtrates of the different particle size classes are sterilised, dried, weighed and homogenised, if necessary. Conventional methods for MP analysis are infrared and raman spectroscopy, giving information on the shapes and numbers of individually identified MP particles. Our focus is on the determination of mass contents of various polymers potentially contained in environmental samples. For qualitative and quantitative MP detection TED-GC-MS is used, a two-step method based on gas chromatography-mass spectrometry (GC-MS) with previous thermal extraction. This method not only enables us to screen the samples for characteristic marker-molecules, thus identifying single polymers, but furthermore allows the calculation of mass contents of individual polymers. In the present work, different freshwater compartments were exemplarily studied to identify containing polymers and calculate their mass content in MP particles. T2 - MICRO2018 CY - Lanzarote, Spain DA - 19.11.2018 KW - Microplastic KW - TED-GC-MS KW - Mass contents PY - 2018 AN - OPUS4-46739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobol, Oded T1 - Sputtering derived artefacts in austenitic steel during Time-of-Flight Secondary Ion Mass Spectrometry analyses N2 - Among the very few techniques to localize hydrogen (H) at the microscale in steels, Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was proven to be a reliable tool. The necessity to detect hydrogen stems from its deleterious effects in metals, that are often used as structural components and to obtain better understanding of the underlying metallurgical mechanisms of hydrogen embrittlement (HE) which are still unclear. Austenitic stainless steels are nowadays commonly used in a wide variety of application, from hydrogen transport and storage facilities to petrochemical and offshore applications where they are exposed to aggressive environments and therefore prone to HE. One of the greater risks in the austenitic class is the embrittlement of the material due to the instability of the γ austenite and its transformation into a brittle α martensitic phase. This transformation takes place due to the local stresses that are induced by the uptake of hydrogen during service. Nonetheless, it was shown that this transformation can occur as an artefact during SIMS analysis itself where Cs-sputtering is necessary not only to remove surface contaminations but mainly to enhance H/D secondary ion yield. In the following contribution we show the influence of different sputtering conditions on AISI 304L austenitic stainless steel in order to distinguish the artefact from the hydrogen induced transformation. The material was charged electrochemically in a deuterium based electrolyte. Deuterium (D) must be in these experiments as a replacement for hydrogen which cannot be used because adsorbed hydrogen superimposes hydrogen originating from charging the sample in the SIMS images. ToF-SIMS analyses were conducted by ToF SIMS IV (IONTOF GmbH, Münster, Germany). The experiments were carried out on deuterium charged and non-charged samples. The structural characterization was carried out by SEM and EBSD examinations before and after charging, both with a Leo Gemeni 1530VP field-emission scanning electron microscope and a Zeiss Supra 40 instrument (Carl Zeiss Microscopy GmbH, Oberkochen, Germany). The results showed that the use of 1keV Cs+ beam induces stacking faults while higher sputter beam energies results in γ→α transformation. T2 - SIMS Europe 2018 CY - Münster, Germany DA - 16.09.2018 KW - Austenitic steel KW - Hydrogen KW - ToF-SIMS KW - Artefact PY - 2018 AN - OPUS4-46701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Kricheldorf, H. T1 - Transesterification in alcohol-initiated ROPs of l- and meso-lactide catalyzed by Sn(II) and Sn(IV) compounds at low temperatures N2 - The purpose of this study is to shed more light on the transesterification processes in alcohol-initiated and tin(II) 2-ethylhexanoate (SnOct2)-catalyzed polymerizations of lactides at low or moderate temperatures. Ethanol-initiated polymerizations are conducted in concentrated solutions at 80 °C and a strong dependence of even/odd equilibration on the alcohol/Sn ratio. Around or above 120 °C cyclization of poly(l-lactide) via “backbiting” occurs as a third mechanism. However, poly(m-lactide) shows a higher cyclization tendency and yields cyclics even at 100 °C. Combinations of ethanol and certain cyclic dibutyltin(IV) catalysts also yield cyclic oligomers of l-lactide at 80 °C. Reaction conditions allowing for a total suppression of all transesterification reactions are not found, but even-numbered poly(m-lactide)s with a purity >95% are obtained at 70 or 60 °C. KW - Cyclization KW - MALDI-TOF MS KW - Polyester KW - Polylactide KW - Transesterification PY - 2018 DO - https://doi.org/10.1002/macp.201800445 SN - 1022-1352 SN - 1521-3935 VL - 219 IS - 24 SP - 1800445, 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-46705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas T1 - Thin polymer films as model systems for polymer nanocomposites N2 - Polymers at interfaces play a major role in a broad variety of applications ranging from engineering purposes (for instance polymer based nanocomposites) to high tech implications (for instance light emitting diodes). Here, thin films with thicknesses down to few nanometers are prepared on different substrates as model systems for polymer composites. The thin films are investigated by a combination of surface analytical and volume sensitive methods. As surface analytical methods atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements (CAM) are employed. As volume sensitive broadband dielectric spectroscopy (BDS), specific heat spectroscopy (SHS), and ellipsometry are used. Especially attention is paid to understand the glass transition behavior of thin films because the glass transition is the key phenomenon determines the application of polymers also in thin films. To understand the glass transition behavior of thin films, which is controversially discussed in literature, a three layer model is discussed. Firstly, a mobile surface layer is assumed at polymer air interface of the film due to missing of segment/segment interactions. Secondly, in the middle of the film a bulk-like layer should be expected. Thirdly, for polymers having non-repulsive interactions with the substrate an irreversibly adsorbed layer is expected to be formed. Due the adsorption the molecular mobility of the segments in this layer is slowed down. What is measured for the glass transition of thin films is a complicated average of all of these effects. The different layers are hardly to address separately. Therefore, in the presentation especially model systems are selected and investigated to verify the layer model. T2 - Kolloquiumsvortrag and der Universität des Saarlandes CY - Saarbrücken, Gemany DA - 20.11.2018 KW - Thin polymer films PY - 2018 AN - OPUS4-46692 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schönhals, Andreas A1 - Zorn, R. T1 - Quasi-elastic scattering of high free volume polymers by neutron time-of-flight spectroscopy N2 - Experimental report to proposal 13562 Quasi-elastic scattering of the polymer with intrinsic microporoasity PIM-1 is measured by neutron time-of-flight spectroscopy and discussed. KW - Neutron scattering KW - PIM-1 PY - 2018 SP - 1 EP - 2 CY - Garching AN - OPUS4-46693 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Anja T1 - Progress Talk 3 / Non-destructive depth profiling of core-shell nanoparticles by ER-XPS N2 - This presentation deals with the progress between month twenty and twenty-nine of my PhD thesis. I prepared it, in order to update my supervisor Prof. Kemnitz and my colleagues from the department of chemistry at the Humboldt-Universität zu Berlin (HU). T2 - Working Group Meeting of Prof. Erhard Kemnitz CY - Humboldt-Universität zu Berlin (HU), Germany DA - 20.11.2018 KW - ER-XPS KW - Synchrotron KW - Core-shell nanoparticles KW - Depth-profiling PY - 2018 AN - OPUS4-46676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Goedecke, Caroline T1 - Mikroplastik - Suchen und Finden N2 - Der Vortrag stellt spektroskopische und neue thermoanalytische Verfahren zum Nachweis von Mikroplastik in Umweltproben vor. Ein spezieller Fokus liegt auf dem neu entwickelten Verfahren der TED-GC-MS. Zusätzlich wird gezeigt, wie die TED-GC-MS eingesetzt werden kann, um Reifen in der Umwelt zu bestimmen. T2 - Fachforum Ressourcen - Kunststoffe und Nachhaltigkeit CY - Leverkusen, Germany DA - 06.11.2018 KW - Mikroplastik KW - TED-GC-MS KW - Thermoanalytische Verfahren KW - Spektroskopische Verfahren PY - 2018 AN - OPUS4-46652 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brandl, F. A1 - Thünemann, Andreas A1 - Beuermann, S. T1 - Poly(meth)acrylate-PVDF core–shell particles from emulsion polymerization: preferential formation of the PVDF β crystal phase N2 - A facile and convenient approach for the synthesis of core–shell particles via emulsion polymerization is presented. The shell consists of poly(vinylidene fluoride) (PVDF) and the core of poly(methyl methacrylate) (PMMA), poly(glycidyl methacrylate) (PGMA) or poly(methyl acrylate) (PMA). In a first step, a non-fluorinated (meth)acrylate monomer is polymerized in the emulsion to produce poly(meth)acrylate core particles. Secondly, vinylidene fluoride (VDF) is directly added to the reactor and polymerized for shell formation. Small-angle X-ray scattering (SAXS) was employed to characterize the structure of the core–shell particles. Interestingly, the particles’ core contains fluorinated and non-fluorinated polymers, whereas the shell of the particles consists only of PVDF. The resulting particles with a diameter of around 40 nm show a significantly higher PVDF β phase content than the PVDF homopolymer obtained by emulsion polymerization KW - Small-angle x-ray scattering KW - SAXS KW - Nanopatricle KW - Polymer PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-465910 DO - https://doi.org/10.1039/C8PY01236A SN - 1759-9954 SN - 1759-9962 VL - 9 IS - 44 SP - 5359 EP - 5369 PB - The Royal Society of Chemistry AN - OPUS4-46591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schütter, Jan T1 - Tailored Micro- and Nanostructured Surfaces for Bacterial Attachment Studies N2 - To investigate the attachment behavior of bacteria, tailored surfaces are needed. Differences in the chemical charge of the substrate are varied by -COO-, -CH3, -OH, -NH3 terminated functional groups. Regular patterns of them on the surfaces enable bacteria to choose their preferred attachment sides. Tools to tailor the samples are µ-contact printing, self-assembled monolayers and physical vapor deposition. The same concept of preferred sides in patterned surfaces is transferred to the nano- and microroughness which is accomplished by using zinc oxide nanorods synthesis. T2 - PhD Retreat CY - Warnemünde, Germany DA - 28.09.2018 KW - ZnO nanorods KW - µ-contact printing KW - Surface modification KW - Microbial induced corrosion PY - 2018 AN - OPUS4-46577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Nanoanalytik-Aktivitäten @ BAM N2 - In dieser Präsentation werden Aktivitäten im Bereich der 'nano'-Charakterisierung bei der BAM vorgestellt. Beispiele von F&E-Projekten und -Kooperationen im nano-Analytik-Bereich bei der BAM werden genannt. Thematische Kooperations-Möglichkeiten zwischen BAM und dem Netzwerk NanoAnalytik und -Messtechnik in der Produktion werden diskutiert. T2 - Treffen des Netzwerkes NanoAnalytik und -Messtechnik CY - Berlin, Germany DA - 06.11.2018 KW - Nanoanalytik KW - Nano-Projekte KW - Nano-Kompetenzzentrum KW - Nano-Charakterisierung PY - 2018 UR - https://www.nanoinitiative-bayern.de/nanoanalytik/ AN - OPUS4-46563 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Anja T1 - Measurement of the thickness and nature of nanoparticle coatings - ISO/PWI TR 23173 N2 - This presentation explains the outline and scientific content of the ISO technical report 23173 "Measurement of the thickness and nature of nanoparticle coatings using electron spectroscopies". This technical report deals with those electron spectroscopy methods that are able to determine the coating thickness of nanoparticles. This specifically includes X-ray photoelectron spectroscopy (XPS), energy-resolved X-Ray photoelectron spectroscopy (ERXPS) using synchrotron radiation, near abient pressure photoelectron spectroscopy (NAPXPS) and Auger electron spectroscopy (AES). T2 - 18. Sitzung des DIN-Normenausschusses 062-08-16 AA CY - Berlin, Germany DA - 08.11.2018 KW - Core-shell nanoparticles KW - Electron spectroscopy KW - XPS KW - Synchrotron radiation KW - AES PY - 2018 AN - OPUS4-46550 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit A1 - Unger, Wolfgang T1 - New work item proposal for a technical report for ISO/TC 201 WG4 “Surface characterization of biomaterials”: Surface chemical analysis – Surface chemical analysis of cells and biofilms N2 - The proposed ISO Technical Report provides a description of a variety of physical methods of analytical chemistry by which bacteria and biofilms can be analysed. The state of the art, sample requirements and strengths associated with each method are identified. Presented at the DIN-meeting for NA 062-08-16 AA „Chemische Oberflächenanalyse und Rastersondenmikroskopie“ T2 - 18. Sitzung des DIN-meeting NA 062-08-16 AA "Chemische Oberflächenanalyse und Rastersondenmikroskopie“ CY - Berlin, Germany DA - 08.11.2018 KW - 3D nano SIMS KW - Fourier transform infrared spectroscopy KW - Raman-spectroscopy KW - Biofilms KW - XPS PY - 2018 AN - OPUS4-46548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diehn, Sabrina A1 - Zimmermann, B. A1 - Bagcioglu, M. A1 - Seifert, Stephan A1 - Kohler, A. A1 - Ohlson, M. A1 - Fjellheim, S. A1 - Weidner, Steffen A1 - Kneipp, Janina T1 - Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) shows adaption of grass pollen composition N2 - MALDI time-of-flight mass spectrometry (MALDI-TOF MS) has become a widely used tool for the classification of biological samples. The complex chemical composition of pollen grains leads to highly specific, fingerprint-like mass spectra, with respect to the pollen species. Beyond the species-specific composition, the variances in pollen chemistry can be hierarchically structured, including the level of different populations, of environmental conditions or different genotypes. We demonstrate here the sensitivity of MALDI-TOF MS regarding the adaption of the chemical composition of three Poaceae (grass) pollen for different populations of parent plants by analyzing the mass spectra with partial least squares discriminant analysis (PLS-DA) and principal component analysis (PCA). Thereby, variances in species, population and specific growth conditions of the plants were observed simultaneously. In particular, the chemical pattern revealed by the MALDI spectra enabled discrimination of the different populations of one species. Specifically, the role of environmental changes and their effect on the pollen chemistry of three different grass species is discussed. Analysis of the Group formation within the respective populations showed a varying influence of plant genotype on the classification, depending on the species, and permits conclusions regarding the respective rigidity or plasticity towards environmental changes. KW - Pollen KW - MALDI-TOF MS KW - Classification KW - Partial least square discriminant analysis (PLS-DA) KW - Principal component analysis (PCA) PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-465294 DO - https://doi.org/10.1038/s41598-018-34800-1 SN - 2045-2322 VL - 8 IS - 1 SP - 16591, 1 EP - 11 PB - Nature AN - OPUS4-46529 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fortini Moustafa Osman, Renata T1 - Development of a method for measuring the rigidity of nanofibers N2 - Over the past decades, the growing industry working for lightweight constructions has demanded materials exhibiting improved properties such as higher mechanical modulus and strength, better chemical resistance and lower costs of production. It is known that especially nanofibers tend to enhance the mechanical, thermal and electrical properties of polymers. Therefore, some types of nanofibers are already being used embedded in polymeric matrix of sports equipment, aircraft parts and automobile components. However, nanofibers are a relatively new material category, the consequences of which for mankind are not yet fully known. Nanofibers detached from polymeric materials can be released into the environment during, e.g., processing and aging. The risks in dealing with such nanofibers are generally unknown, even if further studies of health aspects are being carried out. Problems always arise when the fibers can penetrate the cells, thus the mechanical rigidity of nanofibers is a key factor in assessing the risks. Common methods describe the geometry of nanofibers. These methods are necessary, but not sufficient to describe the mechanical properties, as for during manufacture and aging these properties may change; the modulus and strength values may differ from those of the original fibers. Different experimental techniques for nanomechanical testing have been studied using the atomic force microscope, the scanning electron microscope and transmission electron microscope, showing promising results. This project aims to evaluate the bending stiffness of CNTs with an experimental setup within the Dynamic Scanning Electron Microscope. Based on the Euller-Bernoulli beam theory, the Young’s modulus of CNTs can be obtained using the resonance frequency of mechanically excited nanofibers, its dimensions and density. The resonance frequency is acquired by extracting the signals of the secondary electrons when the nanofibers show significant vibration movement, also possible to be seen on the microscope images. The electronic signals of the secondary electrons are filtered and treated by a lock-in amplifier, so the corresponding amplitude and phase values can be evaluated. This method could be applied to any nanofiber that has the shape similar to a symmetric beam. T2 - Workshop on Reference Nanomaterials Current situation and needs: development, measurement, standarization CY - Berlin, Germany DA - 14.05.2018 KW - Nanofiber KW - Rigidity KW - Resonance KW - DySEM PY - 2018 AN - OPUS4-46527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Smales, Glen Jacob T1 - THE MAUS: A GI-/ULTRA-/W/SAXS Instrument of the future N2 - The Multi-scale Analyzer for Ultrafine Structures or the “MAUS” for short, is a SAXS instrument that combines a multitude of features that make it both unique, and one of the most adaptable instruments around. T2 - SAS2018 CY - Traverse City, MI, USA DA - 07.10.2018 KW - SAXS KW - MAUS KW - Small-angle scattering KW - DAWN KW - Grazing incidence PY - 2018 AN - OPUS4-46523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Julia T1 - AFM-Untersuchungen von funktionellen Beschichtungen und Strukturänderungen unter mechanischer Beanspruchung N2 - Die Rasterkraftmikroskopie (AFM) hat sich in den letzten Jahren als eine vielseitige Abbildungstechnik von Oberflächen mit einer sehr hohen Ortsauflösung etabliert. Über die Untersuchung der reinen Oberflächentopographie sind erweiterte Modi in der Lage, gleichzeitig Informationen über die elektrischen und magnetischen Eigenschaften sowie Adhäsionsprozesse auf Oberflächen zu liefern. Interessanter wird es, wenn das AFM mit geeigneten Messzellen für in-situ-Untersuchungen in kontrollierten Atmosphären oder in Elektrolyten unter elektrochemischer Kontrolle ausgestattet ist. Dies ermöglicht die Untersuchung von Korrosions- und Adhäsionsprozessen unter Bedingungen, die die Betriebsumgebung repräsentieren. Ein aktueller Forschungsschwerpunkt unseres Fachbereiches liegt in den Untersuchungen der Deformationseigenschaften von Funktionsschichten auf Leichtmetalllegierungen, sowie in situ Untersuchungen des Korrosionsverhaltens unter kombinierter korrosiver und mechanischer Beanspruchung mittels AFM. Durch die Integrierung eines Zug-Druckmoduls in den Probentisch des Rasterkraftmikroskops haben wir jetzt die Möglichkeit, verschiedene Materialien uniaxialen Umformversuchen mit bis zu 5 kN Kraft zu unterziehen. Dabei können unter anderem auch zyklische Belastungen genutzt werden, um Ermüdungsprozesse zu simulieren. Da die Messungen in situ ohne die De- und Remontage der Probe durchgeführt werden, ermöglicht der Aufbau nicht nur Messungen mit präziser Positionssteuerung, sondern auch die Untersuchung von Prozessen im elastischen Bereich, die für die Aufklärung der Mechanismen, die zu Ermüdungsversagen führen, entscheidend sind. Die Posterpräsentation wird detaillierte Informationen zum neuen AFM-Setup liefern und unsere aktuellen Ergebnisse zur Verformung dünner Schutzschichten auf AA2024-T3 zusammenfassen. T2 - Hybrid, Materials and Structures CY - Bremen, Germany DA - 18.04.2018 KW - Kelvinsondenkraftmikroskopie KW - Funktionelle Beschichtungen KW - Kombinierete korrosive und mechanische Beanspruchung KW - Lokale Korrosion KW - Delamination KW - Deformation PY - 2018 AN - OPUS4-46522 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jemian, P. T1 - NXcanSAS: standard to store reduced SAS data of any dimension N2 - A SAS-specific extension of the NeXus file standard has been put together for the community to interchangably store measurement data, accompanied by all possible metadata. T2 - XVII International Small Angle Scattering Conference - SAS2018 CY - Traverse City, Michigan, USA DA - 07.10.2018 KW - Small-angle scattering KW - Data standard KW - NeXus KW - Archival format KW - Quality PY - 2018 AN - OPUS4-46521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Snow, T. T1 - Modular SAXS data corrections N2 - A standardized methodology for the correction of scattering patterns, the calculation of uncertainties, the subtraction of backgrounds and solvents, optionally followed by the azimuthal averaging/reduction step, is presented. T2 - XVII International Small Angle Scattering Conference - SAS2018 CY - Traverse City, Michigan, USA DA - 07.10.2018 KW - Small-angle scattering KW - Software KW - Sata corrections KW - Quality PY - 2018 AN - OPUS4-46520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Enhancing your SAXS with interleaved USAXS for less than 50 k€ N2 - A portable, inexpensive module is presented that can enhance good existing SAXS instruments by offering an extension on the angular range to include the ultra-small-angles. The instrument has been shown to work for interleaved SAXS/USAXS experiments. T2 - XVII International Small Angle Scattering Conference - SAS2018 CY - Traverse City, Michigan, USA DA - 07.10.2018 KW - Small-angle scattering KW - USAXS KW - Bonse Hart KW - Instrumentation KW - Data analysis PY - 2018 AN - OPUS4-46519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - How good is SAXS? Results from a large Round Robin on an easy sample N2 - 22 laboratories returned 45 small-angle scattering datasets on a suspension of silver nanoparticles. The variance of the results has been analyzed in order to estimate the expected accuracy and precision of the small-angle scattering technique. T2 - XVII International Small Angle Scattering Conference - SAS2018 CY - Traverse City, Michigan, USA DA - 07.10.2018 KW - Small-angle scattering KW - Round Robin KW - Silver nanoparticles KW - Quality KW - McSAS PY - 2018 AN - OPUS4-46518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - McSAS for SAS analysis: Usage, Benefits and Potential Pitfalls N2 - An introductory lecture for users at the Diamond Light Source, on how to use the McSAS software to analyze their data. T2 - Small Angle Scattering Training School CY - Diamond Light Source, Didcot, United Kingdom DA - 04.06.2018 KW - Small-angle scattering KW - Software KW - Analysis PY - 2018 AN - OPUS4-46517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Julia T1 - Multilayer thin coatings for corrosion protection of AA2024-T3 aluminium alloy N2 - The performance of adhesively joined hybrid components relies strongly on the stability of the adhesive-material interface. With the increasing utilization of multi-material structures in the automotive and aerospace industry, it is of great scientific and technical interest to understand the processes leading to adhesive failure and to develop novel strategies to increase corrosion and delamination resistance of adhesive joints. The aim of this study is to develop thin epoxy based films and their carbon nanofiller loaded composites on aluminium alloy AA2024-T3 and to investigate their interfacial stability under corrosive and coupled corrosive-mechanical load. Spin coating was used for the layer-by-layer deposition of poly[(o-cresyl glycidyl ether)-co-formaldehyde] and poly-(ethylenimine) bi-layers. Carbon nanofillers are introduced either by mixing into the coating components or in between individual layers. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis was performed to investigate the porosity and water uptake of the model films, respectively. Atomic force microscopy (AFM) results indicated a very homogeneous and dense film with low surface roughness. The bi-layer thickness ranged between 30 to 40 nm. Electrochemical measurements show a higher corrosion resistance with the increase of the bi-layer number. The main novelty of this contribution is the in-situ AFM investigations under coupled corrosive-mechanical load. For this purpose, a tensile module capable of uniaxial stretching and compression with up to 5 kN force was integrated into the AFM stage. Stretching experiments were performed to investigate the mechanical properties and adhesion of the films, as well as structural changes of the film morphology during uniaxial deformation. The contribution will provide detailed information on the new AFM setup and summarize our results on the stability of model epoxy and nanocomposite films on AA2024-T3. T2 - EURADH 2018 CY - Lisbon, Portugal DA - 05.09.2018 KW - Electrochemical Empedance Spectroscopy (EIS) KW - Scanning Kelvin Probe Force Microscopy (SKPFM) KW - Corrosion KW - Delamination KW - Aluminium KW - Epoxide PY - 2018 AN - OPUS4-46513 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Analysis of Mesoporous Iridium Oxide Thin Films by the Combined Methodical Approach SEM/EDS/STRATAGem N2 - For the determination of porosity of Ir oxide thin films, electron probe microanalysis (EPMA) can be used as part of a combined SEM/EDS/STRATAGem analysis. The mass deposition (in μg cm-2) of films was calculated with the analysis software STRATAGem via k-values measured with EDS. The average density of coated films was obtained from the mass deposition and the film thickness as measured by the cross-section SEM. The porosity was calculated by dividing the average film density by the bulk (theoretical) density of the film material. Film porosities were counterchecked by spectroscopic ellipsometry (SE) using the Bruggeman effective medium approximation (BEMA). The results obtained by both analytical approaches/methods used, SEM/EDS/STRATAGem and SE were in good agreement. T2 - Microscopy & Microanalysis 2018 CY - Baltimore, MD, USA DA - 05.08.2018 KW - Electron probe microanalysis (EPMA) KW - Iridium oxide KW - Porous thin films KW - Spectroscopic ellipsometry PY - 2018 AN - OPUS4-46509 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dittmann, Daniel T1 - Wasseranalytik oberhalb des Siedepunktes N2 - Das Poster fasst die Möglichkeiten gekoppelter thermischer Analyseverfahren mit Zersetzungsgasanalyse (TGA, TGA-FTIR, TGA-MS, TED-GC-MS) zusammen und stellt ihre Anwendungen für Wasserproben an ausgewählten Beispielen vor. T2 - 3. Mülheimer Wasseranalytisches Seminar (MWAS2018) CY - Mülheim an der Ruhr, Germany DA - 12.09.2018 KW - Thermogravimetrie KW - Zersetzungsgasanalyse KW - Wasseranalytik PY - 2018 AN - OPUS4-46508 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Measurement of Elemental Composition of FeNi and SiGe Thin Films by Electron Probe Microanalysis with Stratagem Software N2 - The present study repeats electron probe microanalysis (EPMA) measurements with the thin film analysis software Stratagem on an Fe-Ni thin films on silicon and reports - for the first-time – results of analysis on Si-Ge thin films deposited on a non-conductive aluminium oxide substrate. If the very good EPMA/Stratagem results for the FeNi system were expected due to previous studies, the data obtained for the SiGe films are particularly valuable, because of the challenging insulator substrate of Al2O3. The conductivity of the Si1-xGex surface necessary for charging-free analysis was ensured by applying conductive copper tape onto film surface down to sample stage. Four accelerating voltages, 15, 20, 25 and 30 kV, have been applied, so that the Ge Kα X-ray line at 9.87 keV could be excited. T2 - Microscopy & Microanalysis 2018 CY - Baltimore, MD, USA DA - 05.08.2018 KW - Electron probe microanalysis (EPMA) KW - Fe-Ni KW - Si-Ge KW - Stratagem KW - X-ray spectroscopy KW - thin film analysis PY - 2018 AN - OPUS4-46506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Electron Microscopy and X-Ray Diffraction Analysis of Titanium Oxide Nanoparticles Synthesized by Pulsed Laser Ablation in Liquid N2 - A femto-second pulsed laser ablation in liquid (PLAL) procedure for the generation of titanium oxide nanoparticles (NP) is reported with the purpose of understanding morphology and structure of the newly generated NPs. Ablation duration was varied for optimization of NP generation processes between 10 and 90 min. Surface morphology of NPs as well as their size and shape (distribution) were analysed by various complementary electron microscopy techniques, i.e. SEM, TSEM and TEM. The crystalline structure of titanium oxide particles was investigated by XRD and HR-TEM. Concentration of generated titanium oxide NPs in liquid was analysed by ICP-MS. A mix of crystalline (mainly anatase), partly crystalline and amorphous spherical titanium oxide NPs can be reported having a mean size between 10 and 20 nm, which is rather independent of the laser ablation (LA) duration. A second component consisting of irregularly shaped, but crystalline titanium oxide nanostructures is co-generated in the LA water, with more pronounced occurrence at longer LA times. The provenance of this component is assigned to those spherical particles generated in suspension and passing through the converging laser beam, being hence subject to secondary irradiation effects, e. g. fragmentation. T2 - Microscopy & Microanalysis 2018 CY - Baltimore, MD, USA DA - 05.08.2018 KW - Nanoparticles KW - Titanium oxide KW - Laser ablation in liquid KW - Electron microscopy KW - XRD PY - 2018 AN - OPUS4-46502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Kricheldorf, H. R. T1 - Spirocyclic bisphenoxides of Ge, Zr, and Sn as catalysts for ring-expansion polymerizations of L- and meso-lactide N2 - Spirocyclic phenoxides of germanium, zirconium, and tin were prepared from 2,20-dihydroxybiphenyl and 2,20-dihydroxy-1,10-binaphthyl. Ring-expansion polymerizations of L-lactide are mainly studied at 160 or 180 °C. The reactivity of the catalysts increases in the order: Zr < Ge < Sn. Regardless of catalyst, the weight-average molecular weights (Mw) never exceed 50,000 g mol−1. The resulting poly(L-lactide)s are optically pure and have a cyclic architecture. Decreasing temperature and time favor Formation of even-numbered cycles, and at 102 ° cyclics, almost free of odd-numbered rings are obtained. Analogous polymerizations of meso-lactide give similar results >120 °C, but different results at 100 or 80 °C. Surprisingly, bell-shaped narrow molecular weight distributions are obtained <140 °C, resembling the pattern of living polymerizations found for alcohol-initiated polymerizations. An unusual transesterification mechanism yielding narrow distributions of odd-numbered cycles is discovered too. KW - Cyclization KW - Polylactides KW - MALDI-TOF MS KW - Ring-opening polymerization KW - Spirocyclic PY - 2018 DO - https://doi.org/10.1002/pola.29259 SN - 0887-624X SN - 1099-0518 VL - 56 IS - 24 SP - 2730 EP - 2738 PB - Wiley Periodicals AN - OPUS4-46498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wurzler, Nina T1 - Effect of conditioning layers on the attachment and biofilm formation of electroactive bacteria on stainless steel N2 - The characteristics of different molecules chosen as representatives for specific functionalities in conditioning layers play an important role on attachment behavior and later biofilm formation of bacteria. The chemical composition is a major component influencing the attachment but there is a conglomerate of influences. T2 - Eurocorr2018 CY - Krakow, Poland DA - 09.09.2018 KW - Conditioning layer KW - Stainless steel KW - Bacterial attachment PY - 2018 AN - OPUS4-46487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang T1 - Chemical modification of graphene and carbon nano tubes as viewed by xps and nexafs spectroscopies with dft spectra simulation N2 - Graphene is a two-dimensional carbon network with unique properties. However, its low solubility, poor reactivity and the limited accessibility of a well-defined basal plane are major challenges for applications. An ideal method to overcome these problems is the covalent attachment of functional molecules to its surface which enable further reactive modifications for specific applications. There are several technologies for surface functionalization of graphene and related CNT materials. To get control on the functionalization process and to optimize the performance of the modified surfaces analytical tools for surface chemical characterization are required. X-ray absorption (NEXAFS) and photoelectron spectroscopy (XPS) have been identified to be rather powerful here [1-3]. Specifically, NEXAFS spectroscopy underpinned by quantum chemical spectrum simulations [4] is unique in a way to address changes of aromaticity and defect formation at the graphene surface during functionalization. For relevant surface modification technologies, we present examples on how NEXAFS and XPS can do a good job. All presented modifications aim on the production of platforms for defined functional 2D nanomaterials, as for example multifunctional hybrid architectures. In detail, we investigated: • A wet chemical method for covalent functionalization of graphene sheets by a one-pot nitrene [2+1] cycloaddition reaction under mild conditions. Here a reaction between 2,4,6-trichloro-1,3,5-triazine and sodium azide with thermally reduced graphene oxide (TRGO) results in defined dichlorotriazine-functionalized graphene sheets. • Graphene and carbon nanotube functionalized by Vacuum-Ultraviolet (VUV) induced photochemical or r.f. cw low pressure plasma processes to introduce amino, hydroxy or brominated functionalities. To underpin finger-print information delivered by C K-edge NEXAFS we studied the effects of selected point and line defects as well as chemical modifications for a single graphene layer model by density functional theory based spectrum simulations. References [1] P.-L. Girard-Lauriault et al., Appl. Surf. Sci., 258 2012 8448-8454, DOI: 10.1016/j.apsusc.2012.03.012 [2] A. Lippitz et al., Surf. Sci., 611 2013 L1-L7, DOI: 10.1016/j.susc.2013.01.020 [3] A. Faghani et al., Angew. Chemie (International ed.), 56 2017 2675-2679, DOI:10.1002/anie.201612422 [4] C. Ehlert, et al., Phys.Chem.Chem.Phys., 16 2014 14083-14095, DOI: 10.1039/c4cp01106f T2 - AVS 65th INTERNATIONAL SYMPOSIUM CY - Long Beach, CA, USA DA - 21.10.2018 KW - Graphene KW - Plasma KW - Nitrene [2+1] cycloaddition KW - XPS KW - NEXAFS PY - 2018 AN - OPUS4-46468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -