TY - JOUR A1 - George, Janine A1 - Petretto, G. A1 - Naik, Aakash Ashok A1 - Esters, M. A1 - Jackson, A. J. A1 - Nelson, R. A1 - Dronskowski, R. A1 - Rignanese, G.-M. A1 - Hautier, G. T1 - Cover profile for the article "Automated bonding analysis with crystal orbital Hamilton populuations" N2 - Invited for this month’s cover are researchers from Bundesanstalt für Materialforschung und -prüfung (Federal Institute for Materials Research and Testing) in Germany, Friedrich Schiller University Jena, Université catholique de Louvain, University of Oregon, Science & Technology Facilities Council, RWTH Aachen University, Hoffmann Institute of Advanced Materials, and Dartmouth College. The cover picture shows a workflow for automatic bonding analysis with Python tools (green python). The bonding analysis itself is performed with the program LOBSTER (red lobster). The starting point is a crystal structure, and the results are automatic assessments of the bonding situation based on Crystal Orbital Hamilton Populations (COHP), including automatic plots and text outputs. Coordination environments and charges are also assessed. More information can be found in the Research Article by J. George, G. Hautier, and co-workers. KW - Automation KW - Chemical bonds KW - High-throughput PY - 2022 DO - https://doi.org/10.1002/cplu.202200246 SN - 2192-6506 SP - 1 EP - 2 PB - Wiley-VCH CY - Weinheim AN - OPUS4-55557 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Terborg, R. A1 - Hodoroaba, Vasile-Dan A1 - Kim, K. J. T1 - Determination of Thin Film Thickness and Composition using Energy Dispersive EPMA N2 - Electron Probe Microanalysis (EPMA) provides a non-destructive approach in the dedicated thin film analysis mode with the commercial StrataGem software. Recently, the open-source programme BadgerFilm by Moy and Fournelle became available. Similarly to StrataGem, it is based on the algorithm of Pouchou and Pichoir and needs intensity ratios of the unknown sample and standards (k-values). We have evaluated the k-values measured for the FeNi and SiGe film systems using the BadgerFilm software package and compared the thickness and composition with the results obtained with the established StrataGem software and other reference methods. The thicknesses of the SiGe films obtained by the BadgerFilm software agree within 20% with the StrataGem and TEM results; the elemental compositions BadgerFilm-StrataGEM agree within 2% with one exception (9%). T2 - Microscopy and Microanalysis 2022 CY - Portland, OR, USA DA - 31.07.2022 KW - Thin films KW - Thickness KW - Elemental composition KW - FeNi KW - SiGe KW - BadgerFilm KW - Electron Probe Microanalysis (EPMA) PY - 2022 AN - OPUS4-55522 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fritzsche, Sven A1 - Jaenisch, Gerd-Rüdiger A1 - Pavasaryte, Lina A1 - Funk, Alexander T1 - XCT and DLW: Synergies of Two Techniques at Sub-Micrometer Resolution N2 - Direct Laser Writing (DLW) and X-ray computed tomography (XCT) both offer unique possibilities in their respective fields. DLW produces full three-dimensional (3D) polymer structures on the microscale with resolutions below 100 nm. The fabricated structures can be analysed by XCT or X-ray microscopy (XRM), which incorporates additional X-ray lenses, in three dimensions down to a minimal basic spatial resolution of about 500 nm or 50 nm, respectively. In this work, two different DLW structures are analysed via XCT. Internal defects are detected and analysed for the purpose of quality control. Defects and structures with sizes down to 1.5 µm are successfully analysed. A 3D reconstruction and internal, hidden features of the fabricated structures are shown and discussed. In a first-of-its-kind study, we demonstrate the detectability of a single-voxel line inside a fabricated structure that would not be detectable with SEM or light microscopy. Furthermore, the direct fabrication on a PET substrate is shown to overcome the high X-ray absorbance of commonly used glass substrates. Attenuation spectra of SZ2080 and glass substrates are compared to a fabrication route direct on a 170 µm PET foil. The practical aspects of XCT measurements for DLW structures on different substrates will be discussed. KW - Non-destructive testing KW - Two-photon polymerization KW - X-ray microscopy KW - XCT KW - 2PP KW - Direct laser writing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560525 DO - https://doi.org/10.3390/app122010488 VL - 12 IS - 20 SP - 1 EP - 15 PB - MDPI CY - Basel AN - OPUS4-56052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lüdicke, M. G. A1 - Hildebrandt, Jana A1 - Schindler, C. A1 - Sperling, R. A. A1 - Maskos, M. T1 - Automated QuantumDots Purification via Solid Phase Extraction N2 - The separation of colloidal nanocrystals from their original synthesis medium is an essential process step towards their application, however, the costs on a preparative scale are still a constraint. A new combination of approaches for the purification of hydrophobic Quantum Dots is presented, resulting in an efficient scalable process in regard to time and solvent consumption, using common laboratory equipment and low-cost materials. The procedure is based on a combination of solvent-induced adhesion and solid phase extraction. The platform allows the transition from manual handling towards automation, yielding an overall purification performance similar to one conventional batch precipitation/centrifugation step, which was investigated by thermogravimetry and gas chromatography. The distinct miscibility gaps between surfactants used as nanoparticle capping agents, original and extraction medium are clarified by their phase diagrams, which confirmed the outcome of the flow chemistry process. Furthermore, the solubility behavior of the Quantum Dots is put into context with the Hansen solubility parameters framework to reasonably decide upon appropriate solvent types. KW - Quantum Dots KW - Purification PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559590 DO - https://doi.org/10.3390/nano12121983 SN - 2079-4991 VL - 12 IS - 12 PB - MDPI CY - Basel AN - OPUS4-55959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brirmi, M A1 - Chabbah, T. A1 - Chatti, S. A1 - Schiets, F. A1 - Casabianca, H. A1 - Marestin, C. A1 - Mercier, R. A1 - Weidner, Steffen A1 - Errachid, A. A1 - Jaffrezic-Renault, N. A1 - Ben Romdhane, H. T1 - Effect of the pendent groups on biobased polymers, obtained from click chemistry suitable, for the adsorption of organic pollutants from water N2 - In this work, four triazole-based poly(ether-pyridine)s polymers were synthesized and used as an adsorbent for the removal of phenolic compounds from aqueous solutions. For this purpose, new fluoromonomers containing 1,2,3-triazole units were prepared by the Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction and then used for the elaboration of novel poly(ether-pyridine-triazole)s (PEPTs) by direct polyconden-sation with isosorbide and bisphenol A. Chemical structure of fluorinated pyridinicmonomers as well as resulting polymers was confirmed by 1H and 19F NMR spectroscopic methods. The thermal behavior of the obtained PEPTs was characterized using differential scanning calorimetry and thermogravimetric analysis. Results of sorption showed that polymers can be effectively used as a sorbent for the removal of polarorganic pollutants. The isosorbide-based poly(ether-pyridine-triazole) which contains hydrophilic hydroxyl groups as pendants chains (P4) exhibited the highest sorption efficiencies (78%–100% after 1 h). In order to explain the results an adsorption mech-anism mainly based on π–π interactions and hydrogen bonding with the pendent groups is proposed. KW - Adsorption KW - Biobased polymers KW - Cycloaddition KW - Pentafluoropyridine KW - Phenolic compounds PY - 2022 DO - https://doi.org/10.1002/pat.5809 SN - 1042-7147 SP - 1 EP - 21 PB - Wiley online library AN - OPUS4-55389 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Cocrystal polymorphs & Mechanochemistry - Mechanism & Kinetics N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new crystal forms. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of mechanochemical reactivity and selectivity. Control over ball milling transformations is needed before the transformative potential of mechanochemical processing can be realized. Different analytical methods and their combinations have been developed for the time-resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray absorption spectroscopy, NMR, Raman spectroscopy, and thermography. Here we will discuss our recent results investigating the formation of polymorphic cocrystals thereby elucidating the influence of milling parameters (solvent, temperature, time) and reaction sequences on the formation mechanism and kinetics. For the mechanochemical chlorination reaction of hydantoin normalizing the kinetic profiles to the volume of the milling ball showed clearly that milling reaction kinetics are conserved. Here physical kinetics dominate reaction rates in a ball-milling transformation. Attempting to interpret such kinetics in purely chemical terms risk misinterpreting the results. Our results indicate that time-resolved in situ investigations of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 3rd CEFMC meeting CY - Kashmir, India DA - 31.08.2022 KW - Mechanochemistry KW - Crystal Engeneering PY - 2022 AN - OPUS4-55641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pütz, E. A1 - Smales, Glen Jacob A1 - Jegel, O. A1 - Emmerling, Franziska A1 - Tremel, W. T1 - Tuning ceria catalysts in aqueous media at the nanoscale: how do surface charge and surface defects determine peroxidase- and haloperoxidase-like reactivity N2 - Designing the shape and size of catalyst particles, and their interfacial charge, at the nanometer scale can radically change their performance. We demonstrate this with ceria nanoparticles. In aqueous media, nanoceria is a functional mimic of haloperoxidases, a group of enzymes that oxidize organic substrates, or of peroxidases that can degrade reactive oxygen species (ROS) such as H2O2 by oxidizing an organic substrate. We show that the chemical activity of CeO2−x nanoparticles in haloperoxidase- and peroxidaselike reactions scales with their active surface area, their surface charge, given by the ζ-potential, and their surface defects (via the Ce3+/Ce4+ ratio). Haloperoxidase-like reactions are controlled through the ζ-potential as they involve the adsorption of charged halide anions to the CeO2 surface, whereas peroxidase-like reactions without charged substrates are controlled through the specific surface area SBET. Mesoporous CeO2−x particles, with large surface areas, were prepared via template-free hydrothermal reactions and characterized by small-angle X-ray scattering. Surface area, ζ-potential and the Ce3+/Ce4+ ratio are controlled in a simple and predictable manner by the synthesis time of the hydrothermal reaction as demonstrated by X-ray photoelectron spectroscopy, sorption and ζ-potential measurements. The surface area increased with synthesis time, whilst the Ce3+/Ce4+ ratio scales inversely with decreasing ζ-potential. In this way the catalytic activity of mesoporous CeO2−x particles could be tailored selectively for haloperoxidase- and peroxidase-like reactions. The ease of tuning the surface properties of mesoporous CeO2x particles by varying the synthesis time makes the synthesis a powerful general tool for the preparation of nanocatalysts according to individual needs. KW - SAXS KW - Ceria KW - Zeta potential PY - 2022 DO - https://doi.org/10.1039/D2NR03172H SP - 1 EP - 12 PB - Royal Society of Chemistry AN - OPUS4-55649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mechichi, R. A1 - Chabbah, T. A1 - Chatti, S. A1 - Jlalia, I. A1 - Sanglar, Corinne A1 - Casablanca, H. A1 - Vulliet, E. A1 - Marestin, C. A1 - Mercier, R. A1 - Weidner, Steffen A1 - Errachid, A. A1 - Hammani, M. A1 - Jaffrezic-Renault, N. A1 - Abderrazak, H. T1 - Semi‑interpenetrating Network‑Coated Silica Gel Based on Green Resources for the Efcient Adsorption of Aromatic Pollutants from Waters N2 - In the framework of the development of green analytical chemistry, a silica gel (SG) coated with a semi-penetrating network based on the partially biosourced poly(ethersulfone) is studied for a greener extraction process of aromatic organic pollutants. An optimized composition of the semi-penetrating network (80% of the linear polymer (LP): isosorbide-based poly(ethersulfone) and 20% cross-linking agent (XP) type bismaleimide) leads to a total adsorption of the selected aromatic pollutants, whatever their hydrophilicity. Adsorption characteristic, kinetics and isotherms of the SG-semi-INP LP80/XP20 for p-hydroxybenzoic acid and for toluic acid were studied. Langmuir model led to a better ftting of the adsorption isotherms; the adsorption of toluic acid is easier than that of p-hydroxybenzoic acid. 1/n values of benzoic acid was lower for SGsemi-INP LP80/XP20 compared to biochar and to cross-linked methacrylate resin, showing a higher adsorption efciency. KW - Isosorbide KW - Semi-interpenetrating networks KW - Silica gel modification KW - Aromatic pollutants KW - Adsorption PY - 2022 DO - https://doi.org/10.1007/s42250-022-00463 SN - 2522-5758 SP - 1 EP - 18 PB - Springer AN - OPUS4-55720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas A1 - Yildirim, Arda A1 - Krause, Christina T1 - Multiple glassy dynamics of a homologous series of triphenylene-based columnar liquid crystals – A study by broadband dielectric spectroscopy, advanced calorimetry and Neutron Scattering N2 - Hexakis(n-alkyloxy)triphenylene) (HATn) consisting of an aromatic triphenylene core and alkyl side chains are model discotic liquid crystal (DLC) systems forming a columnar mesophase. In the mesophase, the molecules of HATn self-assemble in columns, which has one-dimensional high charge carrier mobility along the columns. Here, a homologous series of HATn with different length of the alkyl chain (n=5,6,8,10,12) is investigated using differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS) and advanced calorimetric techniques including fast scanning calorimetry (FSC) and specific heat spectroscopy (SHS). The investigation of the phase behavior was done utilizing DSC experiments and the influence of the alkyl chain length on the phase behavior was revealed. By the dielectric investigations probing the molecular mobility, a γ-relaxation due to localized fluctuations as well as two glassy dynamics the αcore and αalkyl relaxation were observed in the temperature range of the plastic crystalline phase. Moreover, the observed glassy dynamics were further studied employing advanced calorimetry. All observed relaxation processes are attributed to the possible specific molecular fluctuations and discussed in detail. From the results a transition at around n=8 from a rigid constrained (n=5,6) to a softer system (n=10,12) on a molecular lenght scale was revealed with increasing alkyl chain length. A counterbalance of two competing effects of a polyethylene like behavior of the alkyl chains in the intercolumnar domains and self-organized confinement is discussed in the context of a hindered glass transition. T2 - 11th Conferenz on Broadband Dielectric Spectroscopy and its Applications CY - San Sebastian, Spain DA - 04.09.2022 KW - Discotic Liquid Crystals PY - 2022 AN - OPUS4-55672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas A1 - Szymoniak, Paulina A1 - Böhning, Martin A1 - Zorn, R. T1 - Inelastic and Quasielastic Neutron Scattering Experiments on Mircroporous Membranes for Green Separation processes N2 - Polymers with intrinsic microporosity are promising candidates for the active separation layer in gas separation membranes. These polymers are characterized by a high permeability and reasonable permselectivity. The latter point is somehow surprising because for microporous systems a more Knudson-like diffusion is expected then a size dependent temperature activated sieving process. It was argued in the framework of a random gate model that molecular fluctuations on a time scale from ps to ns are responsible for the permselectivity. Her a series of microporous polynorbornenes with bulky Si side groups and a rigid backbone are considered which have different microporosity characterized by BET surface area values. First inelastic time-of-flight neutron scattering measurements were carried out to investigate the low frequency density of state (VDOS). The measured data show the characteristic low frequency excess contribution to the VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. It was found the maximum position of the Boson peak correlates with the BET surface area value. For two selected comparable polynorbornenes elastic scans as well as QENS measurements by a combination of neutron time-of-flight and backscattering are carried out. A low temperature relaxation process was found for both polymers. This process was assigned to the methyl group rotation. It was analysed in terms of a jump diffusion in a three-fold potential. The analysis of the dependence of the elastic incoherent structure factor on the scattering vector yields the number of methyl groups which might be immobilized. T2 - MLZ Conference 2022: Neutrons for mobility CY - Lengries, Germany DA - 31.05.2022 KW - Polymers of intrinsic Microporosity PY - 2022 AN - OPUS4-55674 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Standardized workflow for checking the performance of an EDS X-ray spectrometer at a Scanning Electron Microscope N2 - For test laboratories operating under accreditation schemes like ISO/IEC 17025 (ISO/IEC 17025), as the international reference for testing and calibration laboratories wanting to demonstrate their capacity to deliver reliable results, a periodical control of the critical instrumental parameters of an Energy-Dispersive X-ray Spectrometer (EDS) is required. This periodical check of an EDS is specified with exact procedures and materials in the ISO 15632:2021 ”Microbeam Analysis – Selected instrumental performance parameters for the specification and checking of energy-dispersive X-ray spectrometers for use in electron probe microanalysis” (ISO 15632). The EDS check can be simplified to the acquisition of only one 10 kV spectrum from a dedicated test material, EDS-TM002, which is made available by BAM since 2009 (https://webshop.bam.de/webshop_en/). The optional BAM software “EDX spectrometer check” is destined to automatically evaluate this spectrum and determine the performance of the EDS in terms of energy resolution and calibration, as well as possible alteration of low-energy efficiency due to detector contamination. Nearly 200 laboratories have the EDS-TM and associated software package in use. Practical examples based on various types of artifacts occurred in the EDS spectra and a long-term (>10 years) meticulous observation of the own spectrometers will be discussed. Different types of EDS spectrometers are considered, e.g. Si(Li) and SDD, of various window types (AP, the recent one Si3N4 or even windowless), and with different front contact layers (Au and Ni) (Hodoroaba and Procop, 2014). Evaluation of other parameters or effects such as the deadtime at different count rates or pileup effects is also explained with examples. T2 - Workshop "Automated Mineralogy" @ GEOANALYSIS 2022 CY - Freiberg, Germany DA - 06.08.2022 KW - EDS KW - X-ray spectrometer KW - Performance check KW - Test material KW - Standardized check KW - EDS-TM002 PY - 2022 UR - https://geoanalysis2021.de/en/workshops/automated-mineralogy AN - OPUS4-55460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Piquemal, François A1 - Hoffmann, Johannes A1 - Kaya, Khaled A1 - Gaultier, Brice A1 - Fabricius, Norbert A1 - Sachse, René T1 - ELENA: a European project for electrical nanoscale metrology in industry N2 - A competitive advantage in the semiconductors industry is gained through the exploitation of new materials and processes, translating into improved components’ performances. This requires a metrological infrastructure allowing reliable nanoscale characterisation of new materials and devices, particularly in terms of their electrical parameters and properties. Traceability and reliability of nanoscale measurements stand as a major challenge for electrical properties (i.e. resistance, impedance) using conductive atomic force microscopy (C-AFM) and scanning microwave microscopy (SMM) techniques. The non-destructive analysis nature of these two methods is of paramount importance for the characterization of devices and components. However, the state of the art still lacks established measurement protocols, easy to use reference standards, well-defined best practice guides and easy to use 3D models to assess environmental and external stimulation effects. Moreover, costly instrumentation, particularly for high-frequency measurements, still hinders efficient advancements in these directions. ELENA is a 3-years European project that aims at bringing solutions to the aforementioned difficulties. To achieve this goal, the project uses a combination of nanoscale electrodynamic scanning probe methods in combination with optical tools such as spectroscopic ellipsometry on several lateral length scales to determine the electrical properties of layers and small structures. T2 - ICSE-9: The 9th International Conference on Spectroscopic Ellipsometry CY - Beijing, China DA - 2022-05-21 KW - Imaging Ellipsometry KW - Electrical thin layers KW - Scanning Probe methods KW - Hybrid metrology PY - 2022 AN - OPUS4-55464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt-Grund, R. A1 - Sturm, C. A1 - Hertwig, Andreas T1 - Ellipsometry and polarimetry - Classical measurement techniques with always new developments, concepts, and applications N2 - Ellipsometry is a matured experimental method, whose roots reach back into the early phase of modern optics itself. It is often attributed to be invented by Paul Drude in the last decade of the 19th century, but similar techniques had already been applied for years before Drude started his work. With this Special Issue about ellipsometry and related techniques, we hope to bring more attention to this method and advance and propagate it to be used by a broader community. We have collected a good mixture of articles: some texts are more in the line of users’ tutorial and best practice guides; others are intended to show recent developments of the method. With this collection, we also hope to show the generally rapidly expanding possibilities of ellipsometry and polarimetry to draw attention of new users and previously unrelated communities to this valuable tool. KW - Ellipsometry KW - Polarimetry KW - Surfaces KW - Thin films KW - Optical analysis PY - 2022 DO - https://doi.org/10.1515/aot-2022-0025 SN - 2192-8584 SN - 2192-8576 VL - 11 IS - 3-4 (Topical issue: Ellipsometry) SP - 57 EP - 58 PB - De Gruyter CY - Berlin AN - OPUS4-55467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR ED - Schmidt-Grund, R. ED - Sturm, C. ED - Hertwig, Andreas T1 - Topical issue: Ellipsometry N2 - Ellipsometry is a matured experimental method, whose roots reach back into the early phase of modern optics itself. It is often attributed to be invented by Paul Drude in the last decade of the 19th century, but similar techniques had already been applied for years before Drude started his work. With this Special Issue about ellipsometry and related techniques, we hope to bring more attention to this method and advance and propagate it to be used by a broader community. KW - Spectroscopy KW - Ellipsometry KW - Surfaces KW - Thin films KW - Advanced optics KW - Optical measurement technology PY - 2022 UR - https://www.degruyter.com/journal/key/aot/11/3-4/html#contents SN - 2192-8584 SN - 2192-8576 VL - 11 IS - 3-4 SP - 47 EP - 147 PB - De Gruyter CY - Berlin AN - OPUS4-55468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Data-Driven Chemical Understanding N2 - This talk presents my research on data-driven chemical understanding to graduate students in chemistry at the Graduate School Chemistry in Paris. T2 - Workshop : Practical applications of Machine Learning in chemistry: perspectives and pitfalls CY - Paris, France DA - 13.07.2022 KW - Chemical Understanding KW - Automation KW - Bonding Analysis PY - 2022 UR - https://gs-chem13.sciencesconf.org/ AN - OPUS4-55410 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terborg, R. A1 - Kim, K. J. A1 - Hodoroaba, Vasile-Dan T1 - Determination of Thin Film Thickness and Composition using Energy Dispersive EPMA N2 - The thickness of thin films can be measured by various methods, e.g., profilometry, ellipsometry, atomic force microscopy (AFM), or X-ray reflectometry. For the additional determination of thin film composition, techniques like X-ray photoelectron spectroscopy (XPS) or mass spectrometry-based techniques can be used. An alternative non-destructive technique is electron probe microanalysis (EPMA). This method assumes a sample of homogenous (bulk) chemical composition, so that it cannot be usually applied to thin film samples. However, in combination with the thin film software StrataGEM, the thickness as well as the composition of such films on a substrate can be determined. This has been demonstrated for FeNi on Si and SiGe on Al2O3 film systems. For both systems five samples with different elemental composition and a reference were produced and characterised by Korean research institute KRISS using inductively coupled plasma mass spectrometry (ICP-MS), Rutherford backscattering (RBS), and transmission electron microscopy (TEM). These samples were used for an international round robin test. In 2021, a new and open-source thin film evaluation programme called BadgerFilm has been released. It can also be used to determine thin film composition and thickness from intensity ratios of the unknown sample and standards (k-ratios). In this contribution, we re-evaluated the data acquired for the FeNi and SiGe systems using the BadgerFilm software package and compared the resulting composition and thickness with the results of the established StrataGEM software and other reference methods. With the current evaluation, the BadgerFilm software shows good agreement with the composition and thickness calculated by StrataGEM and as the reference values provided by the KRISS. KW - Thin films KW - Elemental composition KW - Film thickness KW - EPMA (Electron Probe Microanalysis) PY - 2022 DO - https://doi.org/10.1017/S143192762200318X VL - 28 IS - Suppl. 1 SP - 672 EP - 673 PB - Cambridge University Press AN - OPUS4-55437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pellegrino, Francesco A1 - Maurino, V. A1 - Hodoroaba, Vasile-Dan T1 - Morphological Characterization and Chemical Identification of TiO2 Nanoparticles Doped with Ultrafine Metal Particles for Enhanced Photocatalytical Activity N2 - The conversion of solar energy into electricity and solar fuels is of crucial importance for a green and sustainable future. Water splitting using semiconductor photo-catalysts is considered a sustainable method to produce clean hydrogen (H2) fuel. Nevertheless, H2 photo-production efficiency remains still low, although extensive research works to understand better the mechanisms of the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are being carried out. In this respect, TiO2 is a key photoactive material, usually employed with a co-catalyst deposited onto the surface to enhance charge carriers’ separation and catalyze surface charge transfer reactions. The deposition of a co-catalyst on the TiO2 nanoparticle surface represents one successful way to enhance the activity of the photocatalyst through a modification of its surface and redox properties. In this context, high-resolution scanning electron microscopy coupled with elemental analysis by energy-dispersive X-ray spectroscopy (EDS) is fundamental for studying and understanding the effect of the nanoparticle morphology on the functional properties of shape-controlled TiO2 crystals (bipyramides, platelets, and elongated particles). Different types of metal-semiconductor combinations, TiO2 shapes and dopant metals (Ag, Pt, etc) and metal concentrations will be discussed. KW - Nanoparticles KW - Photocatalysis KW - Electron microscopy KW - EDS KW - Metal-semiconductor PY - 2022 DO - https://doi.org/10.1017/S1431927622010078 VL - 28 IS - Suppl. 1 SP - 2658 EP - 2660 PB - Cambridge University Press AN - OPUS4-55436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Spaltmann, Dirk A1 - Ayerdi, J. A1 - Slachciak, Nadine A1 - Llavori, I. A1 - Zabala, A. A1 - Aginagalde, A. A1 - Bonse, Jörn T1 - Tribological performance of FS-laser-induced periodic surface structures on titanium alloy against different counter-body materials using a ZDDP lubricant additive N2 - In this study the so-called laser-induced periodic surface structures (LIPSS, ripples) were produced on titanium alloy (Ti6Al4V) surfaces upon scan processing in air by a Ti:sapphire femtosecond (fs) laser. The tribological performance of the resulting surfaces was qualified in linear reciprocating sliding tribological tests (RSTT) against balls made of different materials (100Cr6 steel/Al2O3/Si3N4) using different oil-based lubricants. The admixture of the additive 2-ethylhexylzinc-dithiophosphate (ZDDP) to a base oil containing only anti-oxidants and temperature stabilizers disclosed the synergy of the additive with the laser-oxidized nanostructures. This interplay between the laser-textured sample topography and the local chemistry in the tribological contact area reduces friction and wear. T2 - 7th World Tribology Congress - WTC 2022 CY - Lyon, France DA - 11.07.2022 KW - Lubricant additives KW - Laser-induced periodic surface structures (LIPSS) KW - Wear KW - Friction PY - 2022 AN - OPUS4-55318 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanochemical formation of multicomponent crystal systems: Mechanism & Kinetics N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new multicomponent crystal systems. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Different analytical methods and their combinations have been developed for the time resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray adsorption spectroscopy, NMR, Raman spectroscopy, and thermography. Here we will discuss our recent results investigating the formation of (poly-morphic) cocrystals, metal-organic compounds, and salts, thereby elucidating the influence of milling parameters and reaction sequences on the formation mechanism and kinetics. For the mechanochemical chlorination reaction of hydantoin normalizing the kinetic profiles to the volume of the milling ball showed clearly that milling reaction kinetics are conserved. Here physical kinetics dominate reaction rates in a ball-milling transformation. Attempting to interpret such kinetics in purely chemical terms risk misinterpreting the results. Our results indicate that time-resolved in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 25th International Conference on the Chemistry of the Organic Solid State (ICCOSS XXV) CY - Ohrid, Macedonia DA - 03.07.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - Crystal Engineering PY - 2022 AN - OPUS4-55413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanochemical formation of multicomponent crystals systems N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new multicomponent crystal systems. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of mechanochemical reactivity and selectivity. Different analytical methods and their combinations have been developed for the time-resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray absorption spectroscopy, NMR, Raman spectroscopy, and thermography. Here we will discuss our recent results investigating the formation of (polymorphic) cocrystals, metal-organic compounds, and salts, thereby elucidating the influence of milling parameters and reaction sequences on the formation mechanism and kinetics. Our results indicate that time-resolved in situ investigations of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 5ECQUL Forging Bonds CY - Lisbon, Portugal DA - 12.07.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - N-Chlorination PY - 2022 AN - OPUS4-55414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Shaken not stirred: enhancing the flavor of mechanochemistry N2 - compounds and cocrystals. The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. Time-resolved in situ investigations of milling reactions (Figure 1) provide direct insights into the underlying mechanisms. We recently introduced different setups enabling in situ investigation of mechanochemical reactions using synchrotron XRD and XAS combined with Raman spectroscopy and thermography. The presented setup allows the detection of crystalline, amorphous, eutectic, and liquid intermediates. Furthermore, the chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key to future optimization of mechanochemical syntheses. In this contribution, we will discuss our recent results investigating the formation of (polymorphic) cocrystals and coordination polymers. Our results indicate that time-resolved in situ investigations of mechanochemical processes are key for tuning and optimizing mechanochemical syntheses allowing to unleash the potential of mechanochemistry for a green materials design. T2 - 2nd National Crystallographic Meeting Lisbon, Portugal CY - Lisbon, Portugal DA - 15.07.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - Crystal PY - 2022 AN - OPUS4-55415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanochemical formation of multicomponent crystal systems: Mechanism & Kinetics N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new multicomponent crystal systems. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Different analytical methods and their combinations have been developed for the time resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray adsorption spectroscopy, NMR, Raman spectroscopy, and thermography.1 Here we will discuss our recent results investigating the formation of (polymorphic) cocrystals2–3 and metal-organic frameworks,4 thereby elucidating the influence of milling parameters and reaction sequences on the formation mechanism and kinetics. For the mechanochemical chlorination reaction of hydantoin normalizing the kinetic profiles to the volume of the milling ball showed clearly that milling reaction kinetics are conserved.6 Here physical kinetics dominate reaction rates in a ball-milling transformation. Attempting to interpret such kinetics in purely chemical terms risk misinterpreting the results. Our results indicate that time-resolved in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 10th International conference on Mechanochemistry and Mechanical Alloying CY - Cagliari, Italy DA - 06.06.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - Cocrystal PY - 2022 AN - OPUS4-55421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Wasmuth, Karsten A1 - Voss, Heike A1 - Krüger, Jörg A1 - Gräf, S. T1 - Laser-induced Periodic Surface Structures - Mechanisms, Applications, and unsolved Problems N2 - Laser-induced Periodic Surface Structures (LIPSS, ripples) are a universal phenomenon and can be generated in a contactless, single-step process on almost any type of solid upon irradiation with intense laser pulses. They represent a (quasi-)periodic modulation of the surface topography in the form of a linear grating and are typically formed in a “self-ordered” way in the focus of a laser beam. Thus, they are often accompanying laser material processing applications. The structural sizes of LIPSS typically range from several micrometers down to less than 100 nanometers – far beyond the optical diffraction limit – while their orientations exhibit a clear correlation with the local polarization direction of the laser radiation. From a theoretical point of view, a controversial debate has emerged during the last decades, whether LIPSS originate from electromagnetic effects (seeded already during the laser irradiation) – or whether they emerge from matter-reorganization processes (distinctly after the laser irradiation). From a practical point of view, however, LIPSS represent a simple and robust way for the nanostructuring of solids that allows creating a wide range of different surface functionalities featuring applications in optics, tribology, medicine, energy technologies, etc. While the currently available laser and scanner technology already allows surface processing rates at the m^2/min level, industrial applications of LIPSS are sometimes limited by the complex interplay between the nanoscale surface topography and the specific surface chemistry. This typically manifests in difficulties to control the processing of LIPSS and in limitations to ensure the long-term stability of the created surface functions. This presentation reviews the currently existent theories of LIPSS. A focus is laid on the historic development of the fundamental ideas behind the LIPSS, their corresponding mathematical descriptions and numerical implementations, along with a comparison and critical assessment of the different approaches. Moreover, some unsolved scientific problems related to LIPSS are identified and the pending technological limitations are discussed. Hereby, it is intended to stimulate further research and developments in the field of LIPSS for overcoming these limitations and for supporting the transfer of the LIPSS technology into industry. T2 - SPIG 2022 - 31st Summer School and International Symposium on the Physics of Ionized Gases CY - Belgrade, Serbia DA - 05.09.2022 KW - Laser-induced periodic surface structures (LIPSS) KW - Surface functionalization KW - Femtosecond laser processing PY - 2022 AN - OPUS4-55813 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Wasmuth, Karsten A1 - Voss, Heike A1 - Krüger, Jörg A1 - Gräf, S. T1 - Laser-induced Periodic Surface Structures (LIPSS): Mechanisms, Applications, and unsolved Problems N2 - Laser-induced Periodic Surface Structures (LIPSS, ripples) are a universal phenomenon and can be generated in a contactless, single-step process on almost any type of solid upon irradiation with intense laser pulses. They represent a (quasi-)periodic modulation of the surface topography in the form of a linear grating and are typically formed in a “self-ordered” way in the focus of a laser beam. Thus, they are often accompanying laser material processing applications. The structural sizes of LIPSS typically range from several micrometers down to less than 100 nanometers – far beyond the optical diffraction limit – while their orientations exhibit a clear correlation with the local polarization direction of the laser radiation. From a theoretical point of view, a controversial debate has emerged during the last decades, whether LIPSS originate from electromagnetic effects (seeded already during the laser irradiation) – or whether they emerge from matter-reorganization processes (distinctly after the laser irradiation). From a practical point of view, however, LIPSS represent a simple and robust way for the nanostructuring of solids that allows creating a wide range of different surface functionalities featuring applications in optics, tribology, medicine, energy technologies, etc. While the currently available laser and scanner technology already allows surface processing rates at the m^2/min level, industrial applications of LIPSS are sometimes limited by the complex interplay between the nanoscale surface topography and the specific surface chemistry. This typically manifests in difficulties to control the processing of LIPSS and in limitations to ensure the long-term stability of the created surface functions. This presentation reviews the currently existent theories of LIPSS. A focus is laid on the historic development of the fundamental ideas behind the LIPSS, their corresponding mathematical descriptions and numerical implementations, along with a comparison and critical assessment of the different approaches. Moreover, some unsolved scientific problems related to LIPSS are identified and the pending technological limitations are discussed. Hereby, it is intended to stimulate further research and developments in the field of LIPSS for overcoming these limitations and for supporting the transfer of the LIPSS technology into industry T2 - 10th International LIPSS Workshop 2022 CY - Orléans, France DA - 21.09.2022 KW - Laser-induced periodic surface structures (LIPSS) KW - Surface functionalization KW - Femtosecond laser processing KW - Time-resolved coherent scattering PY - 2022 AN - OPUS4-55814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob T1 - The Human Factor: Results of a Data Analysis Round Robin N2 - How much do we, the small-angle scatterers, influence the results of an investigation? What uncertainty do we add by our human diversity in thoughts and approaches, and is this significant compared to the uncertainty from the instrumental measurement factors? After our previous Round Robin on data collection, we know that many laboratories can collect reasonably consistent small-angle scattering data on easy samples1. To investigate the next, human component, we compiled four existing datasets from globular (roughly spherical) scatterers, each exhibiting a common complication, and asked the participants to apply their usual methods and toolset to the quantification of the results https://lookingatnothing.com/index.php/archives/3274). Accompanying the datasets was a modicum of accompanying information to help with the interpretation of the data, similar to what we normally receive from our collaborators. More than 30 participants reported back with volume fractions, mean sizes and size distribution widths of the particle populations in the samples, as well as information on their self-assessed level of experience and years in the field. While the Round Robin is still underway (until the 25th of April, 2022), the initial results already show significant spread in the results. Some of these are due to the variety in interpretation of the meaning of the requested parameters, as well as simple human errors, both of which are easy to correct for. Nevertheless, even after correcting for these differences in understanding, a significant spread remains. This highlights an urgent challenge to our community: how can we better help ourselves and our colleagues obtain more reliable results, how could we take the human factor out of the equation, so to speak? In this talk, we will introduce the four datasets, their origins and challenges. Hot off the press, we will summarize the anonymized, quantified results of the Data Analysis Round Robin. (Incidentally, we will also see if a correlation exists between experience and proximity of the result to the median). Lastly, potential avenues for improving our field will be offered based on the findings, ranging from low-effort yet somehow controversial improvements, to high-effort foundational considerations. T2 - International Small-Angle Scattering Conference (SAS2022) CY - Campinas, Brazil DA - 11.09.2022 KW - Round robin KW - Data analysis KW - Small angle scattering KW - Nanomaterials KW - MOUSE KW - Interlaboratory comparison KW - Intercomparability KW - Reliability KW - Data analysis round robin KW - Large number of participants PY - 2022 AN - OPUS4-55762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Deumer, J. A1 - Pauw, Brian Richard A1 - Marguet, S. A1 - Skroblin, D. A1 - Taché, O. A1 - Krumrey, M. A1 - Gollwitzer, C. T1 - Small-angle X-ray scattering: characterization of cubic Au nanoparticles using Debye’s scattering formula N2 - A versatile software package in the form of a Python extension, named CDEF (computing Debye’s scattering formula for extraordinary form factors), is proposed to calculate approximate scattering profiles of arbitrarily shaped nanoparticles for small-angle X-ray scattering (SAXS). CDEF generates a quasi-randomly distributed point cloud in the desired particle shape and then applies the open-source software DEBYER for efficient evaluation of Debye’s scattering formula to calculate the SAXS pattern (https://github.com/j-from-b/CDEF). If self-correlation of the scattering signal is not omitted, the quasi-random distribution provides faster convergence compared with a true-random distribution of the scatterers, especially at higher momentum transfer. The usage of the software is demonstrated for the evaluation of scattering data of Au nanocubes with rounded edges, which were measured at the four-crystal monochromator beamline of PTB at the synchrotron radiation facility BESSY II in Berlin. The implementation is fast enough to run on a single desktop computer and perform model fits within minutes. The accuracy of the method was analyzed by comparison with analytically known form factors and verified with another implementation, the SPONGE, based on a similar principle with fewer approximations. Additionally, the SPONGE coupled to McSAS3 allows one to retrieve information on the uncertainty of the size distribution using a Monte Carlo uncertainty estimation algorithm. KW - X-ray scattering KW - SAXS KW - Non-spherical nanoparticles KW - Nanoparticles KW - Nanomaterials KW - Debye scattering equation KW - Simulation KW - Data fitting PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557652 DO - https://doi.org/10.1107/S160057672200499X VL - 55 IS - Pt 4 SP - 993 EP - 1001 PB - International Union of Crystallography CY - Chester, England AN - OPUS4-55765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emamverdi, Farnaz A1 - Yin, Huajie A1 - Schönhals, Andreas A1 - Böhning, Martin T1 - Molecular Mobility and Physical Aging of Polymers with Intrinsic Microporosity (PIM-1) Revisited: A Big Glassy World N2 - Polymeric membranes represent a cost- and energy-efficient solution for gas separation. Recently Polymers of Intrinsic Microporosity (PIMs) have been in a great interest because of their outstanding BET surface area larger than 700m2/g and pore size smaller than 1 nm. PIMs are a promising candidate in gas separation with high permeability and appealing selectivity due to their inefficient packing derived from a combination of ladder-like rigid segments with sites of contortion. However, it is recognized this class of polymers suffer from decrease in performance with time due to physical aging. The initial microporous structures approach a denser state via local chain rearrangements, leading to a dramatic reduction in permeability. As chain packing during film casting and physical aging are the key factors determine the performance in separation applications, characterization of the molecular mobility in these materials has been proved to provide valuable information. In recent research on PIM-1 the archetypal PIM, a molecular relaxation process with high activation energy together with a significant conductivity in the glassy state has been found and explained with the formation of local intermolecular agglomerates due to interaction of π-electrons in aromatic moieties of the polymer backbone. In this work, the dielectric behavior of the polymeric films and their response upon heating (aging) were measured by isothermal frequency scans during different heating/cooling cycles in a broad temperature range down to 133K for the first time. Multiple dielectric processes following Arrhenius behavior were observed. Local fluctuations, Maxwell-Wagner-Sillars (MWS) polarization and structural relaxations were discussed correlating to structural-properties of PIM-1. Up to now, no other work has studied the role of porosity and thermal history of PIM-1 film in dielectric processes. The goal is by eliminating thermal history and considering storing conditions provide better understanding on aging and plasticizing in high free volume glassy polymer PIM-1. T2 - IDS Online Meeting CY - Berlin, Germany DA - 06.09.2021 KW - Physical Aging KW - BDS KW - Microporous structure KW - Permeation PY - 2021 AN - OPUS4-55766 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - VIDEO A1 - Pauw, Brian Richard T1 - Just a minute: X-ray scattering N2 - An extremely brief summary of what X-ray scattering can do for you (X-ray scattering encompasses small-angle X-ray scattering (SAXS), and wide-angle X-ray scattering (WAXS/XRD), amongst others). See my other videos for more detailed explanations on sample selection, data correction, data analysis, etc. KW - X-ray scattering KW - Introduction KW - Materials science KW - Nanostructure investigation KW - MOUSE PY - 2022 UR - https://www.youtube.com/watch?v=jWWNQyaCTHA PB - YouTube, LLC CY - San Bruno, CA, USA AN - OPUS4-55768 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dubey, A. A1 - Hon Keat, C. A1 - Shvartsman, V. A1 - Yusenko, Kirill A1 - Escobar, M. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Hagemann, U. A1 - Kovalenko, S. A1 - Stächler, J. A1 - Lupascu, D. T1 - Mono-, Di-, and Tri-valent Cation Doped BiFe0.95Mn0.05O3 Nanoparticles: Ferroelectric Photocatalysts N2 - The ferroelectricity of multivalent co-doped Bismuth ferrite (BiFeO3; BFO) nanoparticles (NPs) is revealed and utilized for light photocatalysis exploiting their narrow electronic band gap. The photocatalytic activity of ferroelectric photocatalysts BiFe0.95Mn0.05O3 (BFM) NPs and mono-, di-, or tri-valent cations (Ag+, Ca2+, Dy3+; MDT) co-incorporated BFM NPs are studied under ultrasonication and in acidic conditions. We find that such doping enhances the photocatalytic activity of the ferroelectric NPs approximately three times. The correlation of the photocatalytic activity with structural, optical, and electrical properties of the doped NPs is established. The increase of spontaneous polarization by the mono- and tri-valent doping is one of the major factors in enhancing the photocatalytic performance along with other factors such as stronger light absorption in the visible range, low recombination rate of charge carriers and larger surface area of NPs. A-site doping of BFO NPs by divalent elements suppresses the polarization, whereas trivalent (Dy3+) and monovalent (Ag+) cations provide an increase of polarization. The depolarization field in these single domain NPs acts as a driving force to mitigate recombination of the photoinduced charge carriers. KW - Piezoresponse KW - Bismuth Ferrite KW - Nanoparticles KW - Photocatalysis KW - Ferroelectric KW - Polarization PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557230 DO - https://doi.org/10.1002/adfm.202207105 SN - 1616-301X SP - 1 EP - 16 PB - Wiley AN - OPUS4-55723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emamverdi, Farnaz A1 - Schönhals, Andreas A1 - Böhning, Martin T1 - Molecular mobility and gas transport properties of mixed matrix membranes based on PIM-1 and POF fillers N2 - Especially now in times of the energy revolution, the demand for energy-efficient separation processes promotes the advancement of new high-performance materials for use as highly selective separation membranes. Polymers with intrinsic microporosity (PIMs) are of high interest in the field of gas separation membranes. Currently the application of PIMs for membrane technology is still restrained by their strong tendency to physical aging involving a significant loss of their good gas separation properties. Physical aging phenomenon is related to the molecular mobility of PIMs which was investigated by broadband dielectric spectroscopy (BDS) previously [1]. In this work, covalent phosphinine-based framework (Eto-CPSF) was used as a nanofiller (0-10 wt %) in a PIM-1 matrix to potentially enhance the gas transport properties and prevent physical aging. Since molecular mobility is a fundamental parameter determining gas transport as well as physical aging in such a material, our study includes dielectric investigations by BDS of pure PIM-1 and PIM-1/Eto-CPSF mixed matrix membranes to establish a correlation between molecular mobility and gas transport properties. In addition, gas permeability was determined by the time-lag method (0-10 bar pressure) at 35 °C for N2, O2, CH4 and CO2 for all MMMs. The dielectric behavior of the polymeric films and their response upon heating were measured by isothermal frequency scans during different heating/cooling cycles in a broad temperature range up to 250 °C. Multiple dielectric processes following Arrhenius behavior were observed. Local fluctuations, Maxwell-Wagner-Sillars (MWS) polarization and structural relaxations were discussed correlating to structural-properties of PIM-1. As main result for MMMs, the permeability of PIM-1 for CH4 and CO2 gases were increased significantly with only 5 wt% of nanofiller within the polymer matrix. However, this is not observed for Eto-CPSF concentrations higher than ca. 7 wt% probably due to a microphase separated morphology of the nanocomposite system. Furthermore, the permselectivity of membranes for pair gases O2/N2 and CO2/N2 show enhancement up to a concentration of about 7 wt% Eto-CPSF filler. T2 - 11th BDS conference CY - San Sebastian, Spain DA - 04.09.2022 KW - Gas transport KW - BDS KW - Mixed Matrix Membrane KW - Nanocomposite PY - 2022 AN - OPUS4-55752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen A1 - Scheliga, F. T1 - Ring-opening polymerizations of L-Lactide catalyzed by zinc caprylate: Syntheses of cyclic and linear poly(L-lactide)s N2 - Alcohol-initiated ring-opening polymerizations (ROPs) of L-Lactide (LA) were conducted in bulk at 130 °C catalyzed by Zn acetate (ZnAc2), lactate (ZnLac2), or caprylate (ZnCap2). 11-undecenol (UND), 1-hydroxymethylnaphtalene (HMN), and 4-nitrobenzylalcohol (4NB) were used as alcohols. Whereas variation of the alcohols had little effect, the usefulness of the catalysts increased in the order: acetate < lactate < caprylate. Hence, further alcohol-initiated polymerizations were performed with ZnCap2 alone and with variation of the lactide/catalyst (LA/Cat) ratio. With increasing LA/Cat ratio higher fractions of cyclic poly(L-lactide) (PLA) were found, so that the measured degree of polymerization (DP) is considerably lower than the theoretical value (i.e., 2 x LA/alcohol). With neat ZnCap2 cyclic PLAs were the largely prevailing reaction products. For these cyclic PLAs weight average molar masses (Mw) up to 134,000 were obtained and an optical purity around 99% was indicated by 13C NMR spectroscopy and DSC measurements even after 48 h at 150 or 160 °C. KW - Cyclization KW - Lactide KW - Ring opening polymerization KW - Transesterification KW - Zinc catalyst KW - MALDI PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557565 DO - https://doi.org/10.1002/pol.20220328 SN - 2642-4150 SP - 1 EP - 10 PB - Wiley AN - OPUS4-55756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emamverdi, Farnaz A1 - Yin, Huajie A1 - Schönhals, Andreas A1 - Böhning, Martin T1 - Molecular Mobility and Physical Aging of Polymers with Intrinsic Microporosity (PIM-1) Revisited: A Big Glassy World N2 - Polymeric membranes represent a cost- and energy-efficient solution for gas separation. Recently Polymers of Intrinsic Microporosity (PIMs) have been in a great interest because of their outstanding BET surface area larger than 700m2/g and pore size smaller than 1 nm. PIMs are a promising candidate in gas separation with high permeability and appealing selectivity due to their inefficient packing derived from a combination of ladder-like rigid segments with sites of contortion. However, it is recognized this class of polymers suffer from decrease in performance with time due to physical aging. The initial microporous structures approach a denser state via local chain rearrangements, leading to a dramatic reduction in permeability. As chain packing during film casting and physical aging are the key factors determine the performance in separation applications, characterization of the molecular mobility in these materials has been proved to provide valuable information. In recent research on PIM-1 the archetypal PIM, a molecular relaxation process with high activation energy together with a significant conductivity in the glassy state has been found and explained with the formation of local intermolecular agglomerates due to interaction of π-electrons in aromatic moieties of the polymer backbone. In this work, the dielectric behavior of the polymeric films and their response upon heating (aging) were measured by isothermal frequency scans during different heating/cooling cycles in a broad temperature range down to 133K for the first time. Multiple dielectric processes following Arrhenius behavior were observed. Local fluctuations, Maxwell-Wagner-Sillars (MWS) polarization and structural relaxations were discussed correlating to structural-properties of PIM-1. Up to now, no other work has studied the role of porosity and thermal history of PIM-1 film in dielectric processes. The goal is by eliminating thermal history and considering storing conditions provide better understanding on aging and plasticizing in high free volume glassy polymer PIM-1. T2 - Euromembrane conference CY - Copenhagen, Denmark DA - 29.11.2021 KW - Physical aging KW - Membrane KW - Microporous structure KW - Glassy polymer PY - 2021 AN - OPUS4-55758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob T1 - X-ray scattering for nanostructure quantification, and the quest for the perfect experiment N2 - Measuring an X-ray scattering pattern is relatively easy, but measuring a steady stream of high-quality, useful patterns requires significant effort and good laboratory organization. Such laboratory organization can help address the reproducibility crisis in science, and easily multiply the scientific output of a laboratory, while greatly elevating the quality of the measurements. We have demonstrated this for small- and wide-angle X-ray scattering in the MOUSE project (Methodology Optimization for Ultrafine Structure Exploration). With the MOUSE, we have combined a comprehensive and highly automated laboratory workflow with a heavily modified X-ray scattering instrument. This combination allows us to collect fully traceable scattering data, within a well-documented, FAIR-compliant data flow (akin to what is found at the more automated synchrotron beamlines). With two full-time researchers, our lab collects and interprets thousands of datasets, on hundreds of samples, for dozens of projects per year, supporting many users along the entire process from sample selection and preparation, to the analysis of the resulting data. This talk will briefly introduce the foundations of X-ray scattering, present the MOUSE project, and will highlight the proven utility of the methodology for materials science. Upgrades to the methodology will also be discussed, as well as possible avenues for transferring this holistic methodology to other instruments T2 - SNI 2022 CY - Berlin, Germany DA - 05.09.2022 KW - Methodology KW - X-ray scattering KW - Laboratory management KW - Instrumentation utilization KW - MOUSE KW - SAXS KW - WAXS KW - Automation PY - 2022 AN - OPUS4-55760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - VIDEO A1 - Pauw, Brian Richard T1 - How to run a (lab) SAXS instrument efficiently N2 - Here I talk about our holistic approach to X-ray scattering, and what improvements we made to our methodology to make measuring with us a very streamlined process. KW - laboratory management KW - MOUSE KW - X-ray scattering KW - instrument utilization KW - research efficiency KW - automation KW - metadata collection KW - laboratory automation PY - 2022 UR - https://www.youtube.com/watch?v=ncadUQ43Uwc PB - YouTube, LLC CY - San Bruno, CA, USA AN - OPUS4-55761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bruna, F. G. A1 - Prokop, M. A1 - Bystron, T. A1 - Loukrakpam, R. A1 - Melke, J. A1 - Lobo, C. M. S. A1 - Fink, M. A1 - Zhu, M. A1 - Voloshina, E. A1 - Kutter, M. A1 - Hoffmann, H. A1 - Yusenko, Kirill A1 - de Oliveira Guilherme Buzanich, Ana A1 - Röder, B. A1 - Bouzek, K. A1 - Paulus, B. A1 - Roth, C. T1 - Following adsorbed intermediates on a platinum gas diffusion electrode in H3PO3‑containing electrolytes using in situ X‑ray absorption spectroscopy N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalyst with H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR). The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition. KW - H3PO4 life cycle KW - XAS KW - In situ coupling KW - High-temperature fuel cells KW - Δμ XANES KW - H3PO3 PY - 2022 DO - https://doi.org/10.1021/acscatal.2c02630 SN - 2155-5435 VL - 12 IS - 18 SP - 11472 EP - 11484 PB - ACS CY - Washington, DC AN - OPUS4-55815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rautenberg, Max A1 - Bhattacharya, Biswajit A1 - Witt, Julia A1 - Jain, Mohit A1 - Emmerling, Franziska T1 - In situ time-resolved monitoring of mixed-ligand metal–organic framework mechanosynthesis N2 - The mechanism of mixed-ligand metal–organic framework (MOF) formation, and the possible role of intermediate single-ligand metal complexes during mechanosynthesis, have not been explored yet. For the first time, we report here in situ real-time monitoring of the mechanochemical formation mechanism of mixed-ligand MOFs. Our results show that binary phases can act as intermediates or competing products in one-pot and stepwise synthesis. KW - Mechanochemistry KW - Metal-organic-frameworks KW - In situ X-ray diffraction KW - Mixed-ligand MOFs PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558167 DO - https://doi.org/10.1039/D2CE00803C SP - 1 EP - 4 PB - Royal Society of Chemistry AN - OPUS4-55816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yildirim, Arda A1 - Krause, Christina A1 - Zorn, R. A1 - Schönhals, Andreas T1 - Multiple glassy dynamics of a homologous series of triphenylene-based columnar liquid crystals – A study by broadband dielectric spectroscopy, advanced calorimetry and Neutron Scattering N2 - Hexakis(n-alkyloxy)triphenylene) (HATn) consisting of an aromatic triphenylene core and alkyl side chains are model discotic liquid crystal (DLC) systems forming a columnar mesophase. In the mesophase, the molecules of HATn self-assemble in columns, which has one-dimensional high charge carrier mobility along the columns. Here, a homologous series of HATn with different length of the alkyl chain (n=5,6,8,10,12) is investigated using differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS) and advanced calorimetric techniques including fast scanning calorimetry (FSC) and specific heat spectroscopy (SHS). The investigation of the phase behavior was done utilizing DSC experiments and the influence of the alkyl chain length on the phase behavior was revealed. By the dielectric investigations a γ-relaxation due to localized fluctuations as well as two glassy dynamics the αcore and αalkyl relaxation were observed in the temperature range of the plastic crystalline phase. Moreover, the observed glassy dynamics were further studied employing advanced calorimetry. All observed relaxation processes are attributed to the possible specific molecular fluctuations and discussed in detail. From the results a transition at around n=8 from a rigid constrained (n=5,6) to a softer system (n=10,12) on a molecular lenght scale was revealed with increasing alkyl chain length. A counterbalance of two competing effects of a polyethylene like behavior of the alkyl chains in the intercolumnar domains and self-organized confinement is discussed in the context of a hindered glass transition. The results were confirmed by in- and quasielastic neutron scattering T2 - Confit 2022 CY - Grenoble, France DA - 10.10.2022 KW - Glassy Dynamics KW - Discotic Liquid Crystals PY - 2022 AN - OPUS4-56661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard T1 - The SPONGE v.1.0.0: Modeling scattering of shapes by STL input, with absolute intensities and size distribution. N2 - Simulates X-ray and Neutron scattering patterns from arbitrary shapes defined by STL files. Features: - Uses multithreading to compute a number of independent solutions, then uses the variance of the results to estimate an uncertainty on the output. - Can be launched from the command line using an excel sheet to define settings, or from a jupyter notebook. - Outputs scattering patterns in absolute units if the contrast is set. - A Gaussian size distribution is available, where the relative scaling of objects for each repetion can be varied. Recommended to be used with limited width (max. 10%) to avoid artefacts. - Writes results with settings to an archival HDF5 file. Application examples: This software has been used in several studies to date. For example, it has been used here to simulate a model scattering pattern for a cuboid shape, which was then fed forward into the McSAS3 analysis program for analyzing scattering patterns of polydisperse cuboids. A second use is here, where it was used for the modeling of flattened helices. In this paper, scattering pattern features could be matched with particular morphological changes in the structure. Lastly, this paper has an example where it was used to validate the analytical analysis model, and explore the realistic limits of application of the analytical model. KW - Software KW - Scattering pattern analysis KW - Scattering pattern simulation KW - X-ray KW - Neutron KW - Command-line interface KW - Scattering pattern KW - STL file input KW - Python KW - Arbitrary shapes PY - 2023 DO - https://doi.org/10.6084/m9.figshare.21857130.v1 PB - Digital Science CY - Cambridge, MA, USA AN - OPUS4-56815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen T1 - Alcohol-Initiated and SnOct2-Catalyzed Ring-Opening Polymerization (ROP) of L-Lactide in Solution: A Re-investigation N2 - Alcohol-initiated ring-opening polymerizations (ROP) of L-lactide (LA) were studied in solution at 70 °C, whereupon the nature of the alcohol, the LA/initiator ratio, the LA/SnOct2 ratio and the time were varied. In contrast to literature, neat SnOct2 is catalytically active in THF and several aromatic but donor solvents, such as 1,3-dioxolane, dimethylformamide (DMF) or N-methyl pyrrolidone (NMP), strongly reduce the activity of SnOct2. In agreement with literature, no cycles were formed by neat SnOct2 at 70 °C in toluene, whereas almost complete cyclization occurs at 115 °C. This finding is attributed to strongly reduced mobility of the initially formed linear chains having one Sn-O-CH and one anhydride end group. Due to better solvation and enhanced mobility cyclization occurs in THF at 70 °C. KW - Polylactide KW - Ring-opening polymerization KW - MALDI-TOF MS KW - Transesterification PY - 2023 DO - https://doi.org/10.1016/j.eurpolymj.2023.111822 SN - 0014-3057 SP - 1 EP - 18 PB - Elsevier CY - New York, NY [u.a.] AN - OPUS4-56818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pakrashy, S. A1 - Mandal, P. K. A1 - Goswami, J. N. A1 - Dey, S. K. A1 - Choudhury, S. M. A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Alasmary, F. A. A1 - Dolai, M. T1 - Bioinformatics and Network Pharmacology of the First Crystal Structured Clerodin: Anticancer and Antioxidant Potential against Human Breast Carcinoma Cell N2 - Clerodin was isolated from the medicinal plant Clerodendrum infortunatum, and CSD search showed the first crystal structure of clerodin by a single-crystal X-ray diffraction study. We checked its binding potential with target proteins by docking and conducted network pharmacology analysis, ADMET analysis, in silico pathway analysis, normal mode analysis (NMA), and cytotoxic activity studies to evaluate clerodin as a potential anticancer agent. The cell viability studies of clerodin on the human breast carcinoma cell line (MCF-7) showed toxicity on MCF-7 cells but no toxicity toward normal human lymphocyte cells (HLCs). The anticancer mechanism of clerodin was validated by its enhanced capacity to produce intracellular reactive oxygen species (ROS) and to lower the reduced glutathione content in MCF-7 cells. KW - Anticancer KW - Clerodin PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567600 DO - https://doi.org/10.1021/acsomega.2c07173 SN - 2470-1343 VL - 7 IS - 51 SP - 48572 EP - 48582 PB - ACS Publ. CY - Washington, DC AN - OPUS4-56760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naik, Aakash Ashok A1 - George, Janine T1 - Building quantum chemical orbital based bonding descriptor database N2 - Motivation, methodology and and results of our quantum chemical bonding descriptors database presented in form of a Poster T2 - RSC Twitter Conference 2023 CY - Online meeting DA - 28.02.2023 KW - Bonding analysis KW - Automation KW - Materials Informatics KW - Computational Chemistry KW - Database PY - 2023 UR - https://twitter.com/NaikAak/status/1630400167080869893 UR - https://twitter.com/NaikAak/status/1630540436434558977 AN - OPUS4-57101 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - François, P. A1 - Hoffmann, J. A1 - Kaja, K. A1 - Fabricius, N. A1 - Ermilova, Elena A1 - Sachse, René A1 - Gautier, B. T1 - ELENA Project: Creating a simplified uncertainty calculation for industrial applications N2 - In this workpackage of the ELENA project, we develop a way to express the measurement uncertainty of nanoscale determination of electrical propserties. The method developed aims to be usable for industrial contexts and described in technical documents and standards drafts. Standards and reference samples are used to make traceable measurements available for the end user. T2 - Congrès International de Metrologie CY - Lyon, France DA - 06.03.2023 KW - Nanoscale measurements KW - Electrical properties KW - Optical measurements KW - Surfaces KW - Scanning probe measurements PY - 2023 AN - OPUS4-57155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brüngel, R. A1 - Rückert, J. A1 - Müller, P. A1 - Babick, F. A1 - Friedrich, C. M. A1 - Ghanem, A. A1 - Hodoroaba, Vasile-Dan A1 - Mech, A. A1 - Weigel, S. A1 - Wohlleben, W. A1 - Rauscher, H. T1 - NanoDefiner Framework and e-Tool Revisited According to the European Commission’s Nanomaterial Definition 2022/C 229/01 N2 - The new recommended definition of a nanomaterial, 2022/C 229/01, adopted by the European Commission in 2022, will have a considerable impact on European Union legislation addressing chemicals, and therefore tools to implement this new definition are urgently needed. The updated NanoDefiner framework and its e-tool implementation presented here are such instruments, which help stakeholders to find out in a straightforward way whether a material is a nanomaterial or not. They are two major outcomes of the NanoDefine project, which is explicitly referred to in the new definition. This work revisits the framework and e-tool, and elaborates necessary adjustments to make these outcomes applicable for the updated recommendation. A broad set of case studies on representative materials confirms the validity of these adjustments. To further foster the sustainability and applicability of the framework and e-tool, measures for the FAIRification of expert knowledge within the e-tool’s knowledge base are elaborated as well. The updated framework and e-tool are now ready to be used in line with the updated recommendation. The presented approach may serve as an example for reviewing existing guidance and tools developed for the previous definition 2011/696/EU, particularly those adopting NanoDefine project outcomes. KW - Nanomaterial definition KW - Nanomaterial categorisation KW - Nanomaterial regulation KW - Nanomaterial legislation KW - Decision support KW - FAIRification PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571618 DO - https://doi.org/10.3390/nano13060990 SN - 2079-4991 VL - 13 IS - 6 - Special Issue "Identification and Quantification of Nanomaterials" SP - 1 EP - 16 PB - MDPI CY - Basel, CH AN - OPUS4-57161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Seuthe, T. A1 - Grehn, M. A1 - Eberstein, M. A1 - Rosenfeld, A. A1 - Mermillod-Blondin, A. T1 - Time-resolved microscopy of fs-laser-induced heat flows in glasses N2 - Time-resolved phase-contrast microscopy is employed to visualize spatio-temporal thermal transients induced by tight focusing of a single Ti:sapphire fs-laser pulse into a solid dielectric sample. This method relies on the coupling of the refractive index change and the sample temperature through the thermo-optic coefficient dn/dT. The thermal transients are studied on a timescale ranging from 10 ns up to 0.1 ms after laser excitation. Beyond providing direct insights into the laser–matter interaction, analyzing the results obtained also enables quantifying the local thermal diffusivity of the sample on a micrometer scale. Studies conducted in different solid dielectrics, namely amorphous fused silica (a-SiO2), a commercial borosilicate glass (BO33, Schott), and a custom alkaline earth silicate glass (NaSi66), illustrate the applicability of this approach to the investigation of various glassy materials. KW - Femtosecond laser KW - Phase-contrast microscopy KW - Heat diffusion KW - Glasses PY - 2018 DO - https://doi.org/10.1007/s00339-017-1465-5 SN - 0947-8396 SN - 1432-0630 VL - 124 IS - 1 SP - 60, 1 EP - 6 PB - Springer-Verlag AN - OPUS4-43739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen T1 - Ring-expansion polymerization of meso-lactide catalyzed by dibutyltin derivatives N2 - Meso-Lactide was polymerized in bulk at 60, 80, and 100 °C by means of three different types of catalysts: dibutyltinsulfides (2,2-dibutyl-2-stanna-1,3-dithiolane and 2,20-dibutyl-2-stanna-1,3-dithiane), dibutyltin derivatives of substituted cate-chols (BuCa, CyCa, and BzCa), and dibutyltin derivatives of2,2 dihydroxybiphenyl (SnBi) and 2,2-dihydroxy-1,10-binaphthyl(SnNa. Only the latter two catalysts were active at 60 °C. The architecture of the resulting polylactides depends very much on the structure of the catalyst and on the temperature. At the lowest temperature (60 °C), SnBi and SnNa mainly yielded even-numbered linear chains, but SnNa also yielded even-numbered cycles at 100 °C and short reaction times. In contrast,BuCa, CyCa, and BzCa mainly yielded odd-numbered cycles, although the same catalysts yielded even-numbered linear chains when benzylalcohol was added. KW - MALDI-TOF MS KW - Cyclisation KW - Catalysts KW - Polyester KW - Polymerization PY - 2018 DO - https://doi.org/10.1002/pola.28948 SN - 1099-0518 SN - 0022-3832 VL - 56 IS - 7 SP - 749 EP - 759 PB - Wiley Periodicals Inc. AN - OPUS4-44278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Hertwig, Andreas A1 - Othake, N. A1 - Hiratsuka, M. T1 - Ellipsometrische Klassifizierung von Kohlenstoffschichten N2 - Der Vortrag widmet sich der „ELLIPSOMETRISCHE KLASSIFIZIERUNG VON KOHLENSTOFFSCHICHTEN“ und beschreibt die Punkte: 1. Anwendungen Kohlenstoffschichten–Carbon–based films (DLC) aus dem Vortrag N. Ohtakeet. al. (ISO TC 107, Tokyo 2017),2. Präparation der Kohlenstoffschichten für ISO TC 107 Ringversuch aus Vortrag M. Hiratsuka et. al. (ISO TC 107, Tokyo 2017), 3. Ellipsometrische Charakterisierung von Kohlenstoffschichten, Ergebnisse des Ringversuchs (ISO TC 107, Tokyo 2017) Vortrag Beck et. al. und 4.Deutsche Normungsaktivitäten national/international zur Ellipsometrie DIN NA 062-01-061 (DIN 50989-1)/TC 107 (PWI DE)“ im Einzelnen. T2 - Netzwerksymposium “schützen und Veredeln von Oberflächen”, Wildau CY - TH Wildau, Germany DA - 01.03.2018 KW - Anwendung von Kohlenstoffschichten KW - Klassifizierung von Kohlenstoffschichten KW - Ringversuch Ellipsometrie KW - Normung Ellipsometrie PY - 2018 AN - OPUS4-44340 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Building macromolecular mimetics of cell constituents N2 - One of the holy grails in chemistry is to reconstruct some of life’s functions with synthetic materials. In this contribution, we demonstrate that “simple” macromolecular architectures such as dendritic amphiphiles, Janus dendrimers, thermoresponsive and hybrid organic-inorganic (co)polymers enable to mimic some of the functions of proteins for biomineralization, natural bactericides, biological membranes or the stimuli-responsive cytoskeleton. T2 - Makromolekulares Kolloquium Freiburg 2018 CY - Freiburg in Breisgau, Germany DA - 21.02.2018 KW - Thermoresponsive polymers KW - Cytoskeleton mimic PY - 2018 AN - OPUS4-44296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hollamby, M. J. A1 - Smith, C. F. A1 - Britton, M. M. A1 - Danks, A. E. A1 - Schnepp, Z. A1 - Grillo, I. A1 - Pauw, Brian Richard A1 - Kishimura, A. A1 - Nakanishi, T. T1 - The aggregation of an alkyl–C60 derivative as a function of concentration, temperature and solvent type N2 - Contrast-variation small-angle neutron scattering (CV-SANS), small-angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) measurements of diffusion and isothermal titration calorimetry (ITC) are used to gain insight into the aggregation of an alkyl–C60 derivative, molecule 1, in n-hexane, n-decane and toluene as a function of concentration and temperature. Results point to an associative mechanism of aggregation similar to other commonly associating molecules, including non-ionic surfactants or asphaltenes in non-aqueous solvents. Little aggregation is detected in toluene, but small micelle-like structures form in n-alkane solvents, which have a C60-rich core and alkyl-rich shell. The greatest aggregation extent is found in n-hexane, and at 0.1 M the micelles of 1 comprise around 6 molecules at 25 °C. These micelles become smaller when the concentration is lowered, or if the solvent is changed to n-decane. The solution structure is also affected by temperature, with a slightly larger aggregation extent at 10 °C than at 25 °C. At higher concentrations, for example in solutions of 1 above 0.3 M in n-decane, a bicontinuous network becomes apparent. Overall, these findings aid our understanding of the factors driving the assembly of alkyl–π-conjugated hydrophobic amphiphiles such as 1 in solution and thereby represent a step towards the ultimate goal of exploiting this phenomenon to form materials with well-defined order. KW - Complex Molecular Systems KW - Supramolecules KW - Scattering PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-442977 DO - https://doi.org/10.1039/C7CP06348B VL - 20 IS - 5 SP - 3773 EP - 3380 PB - RSC AN - OPUS4-44297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tumanova, N. A1 - Tumanov, N. A1 - Robeyns, K. A1 - Fischer, Franziska A1 - Fusaro, L. A1 - Morelle, F. A1 - Ban, V. A1 - Hautier, G. A1 - Filinchuk, Y. A1 - Wouters, J. A1 - Leyssens, T. A1 - Emmerling, Franziska T1 - Opening Pandora’s Box: Chirality, Polymorphism, and Stoichiometric Diversity in Flurbiprofen/Proline Cocrystals N2 - Proline has been widely used for various cocrystallization applications, including pharmaceutical cocrystals. Combining enantiopure and racemic flurbiprofen and proline, we discovered 18 new crystal structures. Liquid-assisted grinding proved highly efficient to explore all the variety of crystal forms. A unique combination of stateof-the-art characterization techniques, comprising variable temperature in situ X-ray diffraction and in situ ball-milling, along with other physicochemical methods and density functional theory calculations, was indispensable for identifying all the phases. Analyzing the results of in situ ball-milling, we established a stepwise mechanism for the formation of several 1:1 cocrystals via an intermediate 2:1 phase. The nature of the solvent in liquidassisted grinding was found to significantly affect the reaction rate and, in some cases, the reaction pathway. KW - Mechanochemistry KW - Polymorphs KW - In situ PY - 2018 UR - https://pubs.acs.org/doi/abs/10.1021/acs.cgd.7b01436 DO - https://doi.org/10.1021/acs.cgd.7b01436 VL - 18 IS - 2 SP - 954 EP - 961 PB - American Chemical Society AN - OPUS4-44365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kulla, Hannes A1 - Becker, C. A1 - Paulus, B. A1 - Casati, N. A1 - Rademann, K. A1 - Emmerling, Franziska T1 - In situ investigations of a mechanochemical cocrystal formation by X-ray diffraction in two different milling jars N2 - We present an in situ PXRD investigation of the mechanochemical cocrystal formation of pyrazinamide with pimelic acid in two milling jar materials. DFT calculations of the two synthesized polymorphs suggest that the relative stability is based on a conformation change of pyrazinamide in the cocrystal. T2 - 3. BAM-BfR Workshop CY - Berlin, Adlershof, Germany DA - 15.02.2018 KW - Mechanochemistry KW - Cocrystal KW - Polymorph KW - In situ XRD KW - DFT PY - 2018 AN - OPUS4-44315 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle A1 - Asadujjaman, Asad T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from hydrogen-bonding monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Invited talk (Dr. Jean-Francois Lutz) Institut Charles Sadron CY - Strasbourg, France DA - 26.01.2018 KW - Thermoresponsive polymer KW - UCST-type polymer KW - H bonds KW - Diaminopyridine KW - Acrylamide PY - 2018 AN - OPUS4-44001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Asadujjaman, Asad A1 - Espinosa de Oliveira, T. A1 - Mukherji, D. A1 - Bertin, Annabelle T1 - Polyacrylamide ‘‘revisited’’: UCST-type reversible thermoresponsive properties in aqueous alcoholic solutions N2 - Combining experiments and all-atom molecular dynamics simulations, we study the conformational behavior of polyacrylamide (PAM) in aqueous alcohol mixtures over a wide range of temperatures. This study Shows that even when the microscopic interaction is dictated by hydrogen bonding, unlike its counterparts that present a lower critical solution temperature (LCST), PAM shows a counterintuitive tunable upper critical solution temperature (UCST)-type phase transition in water/alcohol mixtures that was not reported before. The Phase transition temperature was found to be tunable between 4 and 60 1C by the type and concentration of alcohol in the mixture as well as by the solution concentration and molecular weight of the polymer. In addition, molecular dynamics simulations confirmed a UCST-like behaviour of the PAM in aqueous alcoholic solutions. Additionally, it was observed that the PAM is more swollen in pure alcohol solutions than in 80% alcoholic solutions due to y-like behaviour. Additionally, in the globular state, the size of the aggregates was found to increase with increasing solvent hydrophobicity and polymer concentration of the solutions. Above ist Phase transition temperature, PAM might be present as individual polymer chains in the coil state (r10 nm). As PAM is a widespread polymer in many biomedical applications (gel electrophoresis, etc.), this finding could be of high relevance for many more practical applications in high performance pharmaceuticals and/or sensors. KW - Thermoresponsive polymer KW - UCST-type polymer KW - Polyacrylamide KW - Water/alcohol mixtures PY - 2018 DO - https://doi.org/10.1039/c7sm02424j SN - 1744-6848 SN - 1744-683X VL - 14 IS - 8 SP - 1336 EP - 1343 PB - Royal Society of Chemistry CY - London AN - OPUS4-44002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yildirim, Arda A1 - Szymoniak, Paulina A1 - Sentker, K. A1 - Butschies, M. A1 - Bühlmeyer, A. A1 - Huber, P. A1 - Laschat, S. A1 - Schönhals, Andreas T1 - Dynamics and ionic conductivity of ionic liquid crystals forming a hexagonal columnar mesophase N2 - For the first time, the molecular mobility of two linear-shaped tetramethylated guanidinium triflate ionic liquid crystals (ILCs) having different length of alkyl chains were investigated by a combination of broadband dielectric spectroscopy (BDS) and specific heat spectroscopy (SHS). By self-assembly, these ILCs can form a hexagonal ordered mesophase besides plastic crystalline phases and the isotropic state. Three dielectric active processes were found by BDS for both samples. At low temperatures, a γ-process in the plastic crystalline state is observed which is assigned to localized fluctuations of methyl groups including nitrogen atoms in the guanidinium head. At higher temperatures but still in the plastic crystalline state, an α1-process takes place. An α2 process was detected by SHS but with a completely different temperature dependence of the relaxation times than that of the α1-relaxation. This result is discussed in detail, and different molecular assignments of the processes are suggested. At even higher temperatures, electrical conductivity is detected and an increase in the DC conductivity by four orders of magnitude at the phase transition from the plastic crystalline to the hexagonal columnar mesophase is found. This result is traced to a change in the charge transport mechanism from a delocalized electron hopping in the stacked aromatic systems (in the plastic phase) to one dominated by an ionic conduction in the quasi-1D ion channels formed along the supermolecular columns in the ILCs hexagonal mesophases. KW - Ionic liquid crystalls PY - 2018 DO - https://doi.org/10.1039/c7cp08186c SN - 1463-9084 SN - 1463-9076 VL - 20 IS - 8 SP - 5626 EP - 5635 PB - Royal Society of Chemistry AN - OPUS4-44254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Griepentrog, Michael A1 - Hertwig, Andreas A1 - Weise, Matthias T1 - White light interference microscopy, ellipsometry, and instrumented indentation testing as reference procedures N2 - The paper addresses “WHITE LIGHT INTERFERENCE MICROSCOPY, ELLIPSOMETRY, AND INSTRUMENTED INDENTATION TESTING AS REFERENCE PROCEDURES“ and is subdivided in the following sections: 1. Measurement vs. testing vs. reference procedures, 2. White light interference microscopy (WLIM) for determination of step height h, 3. Spectroscopic ellipsometry (SE) for determination of layer thickness d and 4. Instrumented indentation testing (IIT) for determination of indentation hardness HIT. The following points are discussed in more detail: methodology of measurement and testing, uncertainty budgets for direct (WLIM), model-based (SE) and formula-based (IIT) reference procedures by means of specific examples. It is shown that standardization efforts are connected to reference procedures. T2 - Referenzverfahren CY - BAM, Berlin, Germany DA - 21.02.2018 KW - Reference procedures KW - Uncertainty budgets KW - White light interference microscopy KW - Spectroscopic ellipsometry KW - Instrumented indentation testing PY - 2018 AN - OPUS4-44256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Wäsche, Rolf A1 - Brandt, Guido A1 - Ehrke, Roman T1 - Tribology in hot steam - for waste heat recovery or for energy harvesting - N2 - The wear rates of self-amted alumina couples show that friction as well as wear is largely determined by the above mentioned hydro-thermal conditions. The presence of water and ist amount available in the surrounding system either in liquid or in gaseous from plays a key role for friction and wear behavior and cabe benefical for the tribological profile of steam degradation resistant materials. Hot steam enhances the tribo-chemical formations of oxides and hydroxides on MgO-ZrO2, alumina and antimony impregnated carbon. T2 - 21th International Colloquium Tribology CY - Stuttgart/Ostfildern, Germany DA - 09.01.2018 KW - Friction KW - Alumina KW - Hot steam PY - 2018 AN - OPUS4-43895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zorn, R. A1 - Yin, Huajie A1 - Lohstroh, W. A1 - Harrison, W. A1 - Budd, P.M. A1 - Pauw, Brian Richard A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - Anomalies in the low frequency vibrational density of states for a polymer with intrinsic microporosity - the Boson peak of PIM-1 N2 - Polymers with intrinsic microporosity are promising candidates for the active separation layer in gas separation membranes. Here, the vibrational density of states (VDOS) for PIM-1, the prototypical polymer with intrinsic microporosity, is investigated by means of inelastic neutron scattering. The results are compared to data measured for a more conventional high-performance polyimide used in gas separation membranes (Matrimid). The measured data show the characteristic low frequency excess contribution to VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. In comparison to the Boson peak of Matrimid, that of PIM-1 is shifted to lower frequencies. This shift is discussed considering the microporous, sponge-like structure of PIM-1 as providing a higher compressibility at the molecular scale than for conventional polymers. For an annealed PIM-1 sample, the Boson peak shifts to higher frequencies in comparison to the un-annealed sample. These changes in the VDOS of the annealed PIM-1 sample are related to changes in the microporous structure as confirmed by X-ray scattering. KW - Polymers KW - Boson peak KW - Neutron scattering KW - Physical aging KW - Polymer of intrinsic microporosity PY - 2018 DO - https://doi.org/10.1039/C7CP07141H SN - 1463-9076 SN - 1463-9084 VL - 20 IS - 3 SP - 1355 EP - 1363 PB - The Royal Society of Chemistry AN - OPUS4-43808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Characterization of co (polyamide)s N2 - Charactrization of Co(polyamide)s Molar mass distribution; Functionalization; supression of end group effects in favor of sequence distribution analysis; Evidence of of randomization with increasing reaction time T2 - Polyamide Meeting, DSM CY - Sittard, The Netherlands DA - 20.04.2018 KW - Liquid chromatography KW - Mass spectrometry of polymers PY - 2018 AN - OPUS4-44747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Griepentrog, Michael A1 - Hertwig, Andreas A1 - Sahre, Mario A1 - Unger, Wolfgang A1 - Hodoroaba, Vasile-Dan A1 - Krüger, Jörg T1 - Plasma Germany, Fachausschuss Normung, Berichtszeitraum Herbst 2017 – Frühjahr 2018 N2 - Der Vortrag gibt den aktuellen Stand der Normung im Bereich der Oberflächen-technik insbesondere der Oberflächenanalytik und der Oberflächenmess- und -prüftechnik wider. Vorgestellt wird der Status technischer Berichte, Normenentwürfe und Normen u.a. zur Charakterisierung von funktionellen Glasoberflächen für bioanalytische Anwendungen, zur Messung der Schichtdicke von Nanomaterialien mittels Ellipsometrie, zur Kalibrierung von Interferometern und Interferenzmikroskopen für die Formmessung, zur Rockwelleindringprüfung zur Bewertung der Schicht-haftung, zu den Grundlagen der Ellipsometrie, zur Messung der Schichtdicke mittels Wirbelstromverfahren, zur Schichtpotentialmessung von Mehrfach-Nickelschichten, zu Filtern und Augenschutzgeräten gegen Laserstrahlung sowie zur Bestimmung der Schichthaftung mittels Zugversuch. T2 - Plasma Germany, Fachausschuss Normung, Frühjahrssitzung CY - Kiel, Germany DA - 17.04.2018 KW - Stand der Normung KW - Oberflächentechnik KW - Oberflächenanalytik KW - Oberflächenmesstechnik KW - Oberflächenprüftechnik PY - 2018 AN - OPUS4-44729 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Sobol, Oded T1 - Hydrogen assisted cracking and transport studied by ToF-SIMS and data fusion with HR-SEM N2 - For almost 150 years it is known that hydrogen has a deleterious effect on the mechanical properties of metallic components. Nowadays, the problem of hydrogen assisted degradation is highly relevant in energy related fields due to the massive use of steel as a structural component in these applications and its sensitivity to hydrogen. Since the discovery of hydrogen assisted cracking (HAC), researchers studied intensively and suggested possible explanations and mechanisms in order to define how hydrogen is affecting the material. In general, it is considered that hydrogen changes the mechanical properties more in terms of ductility (deformation capacities) than in strength (load capacities). Hydrogen concentration is one of three crucial factors in the degradation process, together with the microstructure of the material and the internal/external mechanical load. The relatively high concentration of hydrogen resulting in this loss of ductility can originate during production or before service (e.g. welding processes) and during service (i.e. catholically protected systems to eliminate corrosion processes in sour environments). In parallel to the theoretical work, tremendous efforts were, and are still, invested in searching for a proper method to elucidate, map and quantify the hydrogen in the microstructure, which is the basis for this work. For steels, the focus is mainly on the observations of diffusion processes and the interaction of hydrogen with the microstructure in regions with high local stresses/strains (for example around evolving cracks). The challenge for reaching this goal arises from the fact that accurate indication of hydrogen by means of position, unlike heavier atoms, can be made only by mass spectrometry or by interaction with another element (e.g. silver decoration, special coating and resonant nuclear reaction by nitrogen). In addition to this, the difficulty recording the hydrogen behavior while it rapidly diffuses through the material, leaving only the unpredicted failure, should be taken into account. Although using powerful characterization methods, models and computational simulations, the key to defining the mechanisms behind HAC is still under debate and not fully understood. The relationship between material and hydrogen is determined by three factors, i.e., the material structure and microstructure – determining the physical properties, the mechanical load applied on the material and the hydrogen concentration. It is well known that in order to have a complete definition of HAC these three factors must be examined locally with the minimal scale and the maximal resolution reachable. The major gap is the lack in such a characterization method or a technique by which one has the ability to detect and observe the hydrogen in the metallic microstructure. The commonly used techniques nowadays are capable of characterization of the microstructure without the ability to observe the hydrogen distribution. Global hydrogen concentration and localized hydrogen observation are possible by some techniques which are incapable of indicating a change in the structure or microstructure therefore a comprehensive overview can be gained only by combining several methods. In the presented research, secondary ion mass spectrometry (SIMS) was adopted as the main tool to detect and locally map the hydrogen distribution in two types of duplex stainless steel grades: EN 1.4462 (standard 2205 duplex stainless steel) and EN 1.4162 (2101 lean duplex stainless steel). The term duplex stainless steel (DSS) refers to the austenitic-ferritic microstructure of the steel where the combination of physical and mechanical properties of the two phases is achieved. The DSS was selected as a case study for this work due to the wide use of this grade in many energy and the lack of knowledge on hydrogen behavior in two-phase containing microstructures. ToFSIMS was exploited in-situ and ex-situ in three experimental approaches during or following an electrochemical charging procedure. This type of hydrogen charging was selected as it simulated a procedure of cathodic protection of most sub-water oil and gas extraction and delivery systems. The experimental procedures were: 1. Ex-situ charging followed by ToF-SIMS imaging for basic understanding of hydrogen distribution. 2. Ex-situ charging followed by in-situ mechanical loading to obtain information on hydrogen behavior around a propagating crack. 3. In-situ permeation of hydrogen through a steel membrane inside the ToF-SIMS to obtain information on diffusion behavior of hydrogen in a two-phase microstructure. The comprehensive view of the effect of hydrogen on steel was gained by using supplementary methods, such as high resolution scanning electron microscopy (HR-SEM), focused ion beam (FIB) and electron back-scattered diffraction (EBSD). The state of the art in this work lies in applying both: in-situ experimental approaches and data treatment of the ToF-SIMS raw data. The data treatment includes the combination of data from several sources (data fusion). The results for the ex-situ charging followed by static sample imaging and data fusion showed that when the analyzed surface is directly exposed to the electrolyte the degradation is pronounced differently in the ferrite, austenite and interface. The degradation mechanisms in the ferrite and austenite were reflected by the formation of cracks on the surface of both, where a high concentration of hydrogen was obtained. This result supports the assumption that hydrogen is attracted to highly deformed regions. The advantage of using in-situ charging/permeation in comparison to ex-situ charging is that the effect of hydrogen on the ferrite and austenite phases when the hydrogen is evolving from within the microstructure is realized, in comparison to when the analyzed surface is initially exposed directly to the electrolyte. In both experiments the ferrite was observed as a fast diffusion path for the hydrogen. The faster diffusion of hydrogen through the ferrite is expected due to the higher diffusion coefficient, however, a direct proof for the diffusion sequence in this scale was never shown. Most significant results were achieved by the ‘core’ experiments of this research. These experiments included the design of a novel dynamic mechanical loading device to apply an external load during SIMS imaging of a hydrogen precharged-notched sample. For the first time it was shown that plastic deformation induced by applying a mechanical load is resulting in a redistribution of hydrogen locally around the notch. T3 - BAM Dissertationsreihe - 160 KW - Duplex stainless steels KW - Hydrogen assisted cracking KW - Time-of-Flight secondary ion mass spectrometry KW - Data fusion PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-447331 SN - 1613-4249 VL - 160 SP - I EP - 180 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-44733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen A1 - Kricheldorf, H. A1 - Scheliga, F. T1 - MALDI-TOF-MS for the determination of polymerization mechanisms of biodegradable polymers N2 - Eine neue Art einer Ring-Expansion Polymerization (REP) von zyklischen Polylaktiden mittels neuer Katalysatoren wird präsentiert. MALDI-TOF Massenspektrometrie und andere analytische Techniken wurden zur Aufklärung des Mechanismus eingesetzt. Dabei zeigte sich, dass im Gegensatz zu anderen REP, ausschließlich zyklische Polymere gebildet wurden. Diese stellen neue Kandidatenmaterialien für zukünftige neue CRM dar. T2 - 22. MALDI-Kolloquium CY - Berlin, Germany DA - 15.05.2018 KW - MALDI-TOF MS KW - Polylaktid KW - Zyklen PY - 2018 AN - OPUS4-44835 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Weise, Matthias A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Schukar, Vivien T1 - Faser-basierter magneto-optischer Schicht-Sensor zum Monitoring von Bauteilen N2 - In Glasfasern eingeschriebene Bragg-Gitter (FBG: fibre-based Bragg gratings) sind über die Verschiebung der Bragg-Wellenlänge in der Lage, Stauchungen und Dehnungen von Glasfasern hochgenau zu erfassen. In Kompositwerkstoffe eingebettete faseroptische Sensoren können Bauteile bezüglich ihrer mechanischen Integrität überwachen und früh-zeitig Informationen über Materialveränderungen gewinnen. Um die Zuverlässigkeit eines solchen Sensors zu gewährleisten, ist es wichtig, die korrekte Funktion des Sensors im Verbund mit der Werkstoff-Matrix on-line und in-situ sicherzu-stellen. Im Rahmen des DFG-Projekts FAMOS² (FAser-basierter Magneto-Optischer SchichtSensor) wurde ein selbstdiagnosefähiger Schichtsensor entwickelt, der mit Hilfe von magnetostriktiven Aktorschichten aus Nickel bzw. Eisen-Nickel validiert werden kann. Der FAMOS²-Schichtsensor wird durch ein PVD (physical vapour deposition)/ECD (electro-chemical deposition) Hybridschichtsystem realisiert, das auf dem Fasermantel im Bereich des FBG haftfest, homogen und langzeitfunktional abzuscheiden ist. Dabei wird in einem ersten Schritt ein etwa 100 Nanometer dünnes PVD-Schichtsystem aus Chrom und Kupfer als Haftvermittler auf der Glasfaser bzw. als leitfähige Startschicht für den nachfolgenden ECD-Prozess abgeschieden. Um eine rotationssymmetrische Schich-tabscheidung zu gewährleisten, erfolgt während der PVD-Beschichtung eine Rotation der Glasfasern. In einem zweiten Schritt wird dann unter Verwendung eines klassischen Watts-Elektrolyten in einer speziell entwickelten ebenfalls rotationssymmetrisch aufgebau-ten ECD-Durchströmungszelle dann die etwa 30 Mikrometer dicke, magnetostriktive Ak-torschicht auf dem PVD-Schichtsystem abgeschieden, im Vergleich sowohl reine Nickel-Schichten als auch Nickel-Eisen-Schichten. Ein äußeres Magnetfeld dehnt die magnetostriktive Aktorschicht und damit auch die Faser reversibel. Diese Dehnung führt zu einer Verschiebung der Bragg-Wellenlänge, welche direkt mit der Stärke eines zu messenden oder zu Validierungszwecken vorgegebenen Magnetfeldes korreliert. Die Anpassung der Beschichtungsverfahren an die Fasergeome-trie und die mechanischen Eigenschaften der Hybridschichten werden hinsichtlich der me-chanischen Integrität des faseroptischen Sensors diskutiert und der Nachweis der Selbst-diagnosefähigkeit erbracht. T2 - 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium CY - Zeulenroda, Germany DA - 13.03.2018 KW - Magneto-optischer Sensor KW - Faser-Bragg Gitter KW - Magnetostriktive Beschichtung KW - Selbstkalibrierung KW - Bauteilmonitoring PY - 2018 AN - OPUS4-44598 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Weise, Matthias A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Schukar, Vivien T1 - Faser-basierter magneto-optischer Schicht-Sensor zum Monitoring von Bauteilen N2 - In Glasfasern eingeschriebene Bragg-Gitter (FBG: fibre-based Bragg gratings) sind über die Verschiebung der Bragg-Wellenlänge in der Lage, Stauchungen und Dehnungen von Glasfasern hochgenau zu erfassen. In Kompositwerkstoffe eingebettete faseroptische Sensoren können Bauteile bezüglich ihrer mechanischen Integrität überwachen und früh-zeitig Informationen über Materialveränderungen gewinnen. Um die Zuverlässigkeit eines solchen Sensors zu gewährleisten, ist es wichtig, die korrekte Funktion des Sensors im Verbund mit der Werkstoff-Matrix on-line und in-situ sicherzu-stellen. Im Rahmen des DFG-Projekts FAMOS² (FAser-basierter Magneto-Optischer SchichtSensor) wurde ein selbstdiagnosefähiger Schichtsensor entwickelt, der mit Hilfe von magnetostriktiven Aktorschichten aus Nickel bzw. Eisen-Nickel validiert werden kann. Der FAMOS²-Schichtsensor wird durch ein PVD (physical vapour deposition)/ECD (electro-chemical deposition) Hybridschichtsystem realisiert, das auf dem Fasermantel im Bereich des FBG haftfest, homogen und langzeitfunktional abzuscheiden ist. Dabei wird in einem ersten Schritt ein etwa 100 Nanometer dünnes PVD-Schichtsystem aus Chrom und Kupfer als Haftvermittler auf der Glasfaser bzw. als leitfähige Startschicht für den nachfolgenden ECD-Prozess abgeschieden. Um eine rotationssymmetrische Schich-tabscheidung zu gewährleisten, erfolgt während der PVD-Beschichtung eine Rotation der Glasfasern. In einem zweiten Schritt wird dann unter Verwendung eines klassischen Watts-Elektrolyten in einer speziell entwickelten ebenfalls rotationssymmetrisch aufgebau-ten ECD-Durchströmungszelle dann die etwa 30 Mikrometer dicke, magnetostriktive Ak-torschicht auf dem PVD-Schichtsystem abgeschieden, im Vergleich sowohl reine Nickel-Schichten als auch Nickel-Eisen-Schichten. Ein äußeres Magnetfeld dehnt die magnetostriktive Aktorschicht und damit auch die Faser reversibel. Diese Dehnung führt zu einer Verschiebung der Bragg-Wellenlänge, welche direkt mit der Stärke eines zu messenden oder zu Validierungszwecken vorgegebenen Magnetfeldes korreliert. Die Anpassung der Beschichtungsverfahren an die Fasergeome-trie und die mechanischen Eigenschaften der Hybridschichten werden hinsichtlich der me-chanischen Integrität des faseroptischen Sensors diskutiert und der Nachweis der Selbst-diagnosefähigkeit erbracht. T2 - 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium CY - Zeulenroda, Germany DA - 13.03.2018 KW - Magneto-optischer Sensor KW - Faser-Bragg Gitter KW - Magnetostriktive Beschichtung KW - Selbstkalibrierung KW - Bauteilmonitoring PY - 2018 SN - 978-3-00-058187-8 SP - 1 EP - 5 CY - Jena AN - OPUS4-44599 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Szymoniak, Paulina A1 - Madkour, Sherif A1 - Schönhals, Andreas T1 - Dynamics of nanoscopically confined PVME in thin films of an asymmetric PVME/PS blend N2 - In recent years, substantial efforts have been devoted to investigating nanoscopic confinement of polymers, and its effect on glassy dynamics. Broadband Dielectric Spectroscopy (BDS) was used to study the dynamics of ultra-thin films of PVME/PS 50/50 wt% blend, employing a novel nano-structured capacitor sample arrangement. The investigated system shows a complex dynamic behavior. First, an α-relaxation, related to a bulk-like layer was found. Second, an α’-relaxation was observed, characteristic for dynamically asymmetric blends, where the out of equilibrium dynamics is attributed to weakly-cooperative PVME segments relaxing within a frozen environment of PS segments. Thirdly, for thinnest films, an Arrhenius-like process was dominant in the dielectric spectra, indicating localized fluctuations of the segments. Relaxation rates of this process resembled that of the degenerated α-relaxation of the adsorbed layer, found for pure PVME, thus it was assigned accordingly. For thinnest films, this process undergoes a further confinement, due to the topological constraints, introduced by PS. Such multiple confinement effect has not been reported for ultra-thin films of polymer blends, before this study. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Thin polymeric films PY - 2018 AN - OPUS4-44502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yildirim, Arda A1 - Szymoniak, Paulina A1 - Sentker, K. A1 - Butschies, M. A1 - Bühlmeyer, A. A1 - Laschat, S. A1 - Huber, P. A1 - Schönhals, Andreas T1 - Molecular Mobility and Ionic Conductivity of Ionic Liquid Crystals Forming a Hexagonal Columnar Mesophase N2 - For the first time, the molecular mobility of two linear-shaped tetramethylated guanidinium triflates ionic liquid crystals (ILCs) having different length of alkyl chains was investigated by a combination of broadband dielectric spectroscopy (BDS) and specific heat spectroscopy (SHS). SHS was carried out by differential AC-chip calorimetry at higher frequencies and temperature modulated DSC at lower frequencies. These ILCs can form a hexagonal ordered columnar mesophase. Two relaxation processes were found by BDS for both samples. At low temperatures, a γ-processes is observed which is assigned to specific localized fluctuations. At higher temperatures, α1-processes take place. α2 processes were also detected by SHS but with a completely different temperature dependence of the relaxation times. Different molecular assignments of α1- and α2-processes are suggested. At even higher temperatures, conductivity was detected by BDS. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Ionic liquid crystals PY - 2018 AN - OPUS4-44504 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yildirim, Arda A1 - Sentker, K. A1 - Huber, P. A1 - Schönhals, Andreas T1 - Collective Orientational Order and Phase Behavior of a Discotic Liquid Crystal under Confinement N2 - Discotic liquid crystals (DLCs) are a promising class of soft matter for electronic applications. This is due to their ability to self-organize into columns in a hexagonal columnar mesophase, driven by the overlapping of the π orbitals of their aromatic cores. This leads to a high charge-carrier mobility along the column axis. Previous studies on DLCs showed that their properties, such as phase transition temperatures and enthalpies, are susceptible to nanoconfinement. In this study, 2,3,6,7,10,11 hexakis[hexyloxy] triphenylene (HAT6) was confined into parallel aligned cylindrical nanopores of anodic aluminum oxide (AAO) membranes by melt infiltration. Furthermore, the pore surfaces of a series of membranes were chemically modified, resulting in a more hydrophobic pore surface than the unmodified ones. Collective orientational order and phase behavior of HAT6 confined into modified and unmodified nanopores of AAO were investigated by broadband dielectric spectroscopy and differential scanning calorimetry respectively. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Discotic Liquid Crystals PY - 2018 AN - OPUS4-44506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Omara, Shereen A1 - Turky, Gamal A1 - Rehim, Mona A1 - Schönhals, Andreas T1 - Hyperbranched PAMAM/ Kaolinite Nanocomposites: Decoupling phenomenon and conductivity mechanism N2 - Increasing demands of the daily life requires a continuous discovering of new and tailored properties of materials that can be utilized in covering the requirements in several fields. Hyperbranched polymers (HBPs) are macromolecules that are characterized by a highly branched structure and multiplicity of reactive end groups, which could be promising for numerous applications. Here, hyperbranched poly(amidoamine) (HPAMAM)/ Ka nanocomposites was prepared via an in-situ polymerization and an ex-situ method. The latter approach leads to a partly intercalated structure of the nanocomposites, while the former method results in an exfoliated morphology. Α combination of different techniques such as broadband dielectric spectroscopy (DBS), SXAS, FTIR, TEM, and DSC are employed to study the prepared samples. For the HPAMAM/ Ka-DCA nanocomposites (an ex-situ samples), the results indicated that the dc conductivity is increased by 4 orders of magnitude, with increasing concentration of the Ka-DCA. As an interesting result is that a significant decoupling between the characteristic time for conductivity relaxation and the segmental dynamics was observed, which depends on the concentration of the nanofiller. For the HPAMAM/ EDA nanocomposites (an in-situ polymerization), the dc conductivity is also increased with increasing the concentration of the Ka-EDA. The decoupling phenomenon and conductivity mechanism are discussed in detail. T2 - Spring Meeting of German Physical Socitety CY - Berlin, Germany DA - 12.03.2018 KW - Nanocomposites PY - 2018 AN - OPUS4-44521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Omara, Shereen A1 - Rehim, Mona A1 - Turky, Gamal A1 - Madkour, Sherif A1 - Schönhals, Andreas T1 - Structure−property relationships of hyperbranched polyamine ester/Ka-DCA nanocomposites N2 - Hyperbranched polyamine ester (HPAE)/ kaolinite nanocomposites were papered via an ex situ (solution-based) method. The kaolinite has been modified by dodecylamine (DCA). SAXS measurements revealed that the Ka interlayer space increased from 0.71 to 3.6 nm-1. A partly exfoliated structure of the HPA/Ka-DCA nanocomposites was proved by SAXS and TEM. By a combination of BDS and SHS, the relaxation properties of the nanocomposites were investigated in dependence on frequency and temperature. The activation energies of γ-relaxation for the nanocomposites were lower than the values found for the pure HPAE. The segmental dynamics (α- relaxation) was found to be screened out by the conductivity contribution. While it is retrieved by SHS employing AC-chip calorimetry. A systematic change of the dynamic glass transition estimated by AC-chip calorimetry was observed, which is in agreement with a behavior expected for a confined sample. The confinement effect of the Ka-DCA nanofillers reduces the glass transition temperature Tg and enhances, meanwhile, the electrical conductivity of the polymer. By comparing the temperature dependence of the dynamic glass transition measured with SHS and that of the dc conductivity measured by dielectric spectroscopy, a decoupling in their temperature dependencies was found. With increasing concentration of the nanofiller, which results in a stronger glass-formation behavior, this decoupling becomes weaker. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Nanocomposites PY - 2018 AN - OPUS4-44522 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle A1 - Asadujjaman, Asad A1 - Ahmadi, Vahid T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from hydrogen-bonding monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Deutsche Physikalische Gesellschaft (DPG)-Frühjahrtagung 2018 CY - Berlin, Germany DA - 11.03.2018 KW - Thermoresponsive polymer KW - UCST-type polymer KW - H bonds KW - Diaminopyridine KW - Acrylamide PY - 2018 AN - OPUS4-44569 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Hielscher, Stefan A1 - Lange, Thorid A1 - Grunwald, Daniel A1 - Stockmann, Jörg M. A1 - Lerche, D. A1 - Rietz, U. T1 - Die Zentrifuge als universelles Prüfsystem für Beanspruchungen auf Zug und Druck N2 - Mit der Zentrifugentechnologie ist seit einigen Jahren ein neuartiges Mehr-Proben-Prüf-verfahren auf dem Markt etabliert, welches die klassische Zugprüfung in den Trommelrotor einer Tischzentrifuge überträgt. In der Beanspruchung auf Zug ist die Prüfung der Verbundfestigkeit mittels CAT-Technologie (centrifugal adhesion testing) an der BAM seit 2017 nach DIN EN ISO/IEC 17025 akkreditiert, wobei die Verbundfestigkeit von Klebungen direkt bestimmt wird und in Abhängigkeit von den Versagensformen Rückschlüsse auf die Klebfestigkeit von Klebstoffen/Klebebändern oder die Haftfestigkeit von Beschichtungen gezogen werden können. T2 - 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium CY - Zeulenroda, Germany DA - 13.03.2018 KW - Zentrifugentechnologie KW - Haftfestigkeit KW - Härteprüfung KW - Mehr-Proben-Prüfung KW - Beanspruchung auf Zug und Druck PY - 2018 AN - OPUS4-44570 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hielscher, Stefan A1 - Beck, Uwe A1 - Lange, Thorid A1 - Grunwald, Daniel A1 - Stockmann, Jörg M. A1 - Lerche, D. A1 - Rietz, U. T1 - Die Zentrifuge als universelles Prüfsystem für Beanspruchungen auf Zug und Druck N2 - Mit der Zentrifugentechnologie ist seit einigen Jahren ein neuartiges Mehr-Proben-Prüf-verfahren auf dem Markt etabliert, welches die klassische Zugprüfung in den Trommelrotor einer Tischzentrifuge überträgt. In der Beanspruchung auf Zug ist die Prüfung der Verbundfestigkeit seit 2017 nach DIN EN ISO/IEC 17025 akkreditiert, wobei die Verbundfestigkeit von Klebungen direkt bestimmt wird und in Abhängigkeit von den Versagensformen Rückschlüsse auf die Klebfestigkeit von Klebstoffen/Klebebändern oder die Haftfestigkeit von Beschichtungen gezogen werden können. Bei der zerstörenden Beanspruchung auf Zug ist zu beachten, dass es sich bei der Verbundfestigkeit um eine Systemeigenschaft handelt, d.h. nicht nur die chemischen und topografischen Oberflächeneigenschaften, sondern auch die plasto-elastischen Volumeneigenschaften des Klebstoffes und der Fügeteile haben Einfluss auf die ermittelten Kennwerte. Dabei ist eine qualitative Bestimmung der Versagensformen und Bruchbilder nach DIN EN ISO 10365 zwingend erforderlich, um eine Aussage über die Art des Versagens treffen zu können. Mit der Erweiterung der Zentrifugentechnologie um Beanspruchungen auf Druck wurde dann der Nachweis erbracht, dass auch die klassische Härteprüfung in einer Zentrifuge als Mehr-Proben-Prüfung durchgeführt werden kann. Im Verbundvorhaben QUO VADIS PLUS werden derzeit invasive Beanspruchungen auf Druck zur Bestimmung der Härte von Materialien, der Kompressibilität von Metallschäumen sowie der Kompaktierbarkeit von Pulvern untersucht, was das Anwendungspotential der Zentrifugentechnologie nochmals erweitert. Dazu gehören auch kombinierte Beanspruchungen wie Zug-Scher- und Druck-Scher-Prüfungen. Die Verbundfestigkeit von CFK-Platten in Abhängigkeit der Beanspruchungsart (Zug vs. Zug-Scher) bzw. der Faserorientierung (0°, 45°, 90°), die Klebfestigkeit von Klebstoffen bzw. Klebebändern auf unterschiedlichen Fügeteilwerkstoffen in Abhängigkeit von der Vorbehandlung, die Haftfestigkeit optischer Schichten auf Kunststoffen, die Bestimmung der Vickers-, Brinell- bzw. Kugeldruck-Härte sowie die Kompressibilität von metallischen Schäumen und Federn werden als ausgewählte Beispiele diskutiert. T2 - 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium CY - Zeulenroda, Germany DA - 13.03.2018 KW - Zentrifugentechnologie KW - Haftfestigkeit KW - Härteprüfung KW - Mehr-Proben-Prüfung KW - Beanspruchung auf Zug und Druck PY - 2018 SN - 978-3-00-058187-8 SP - 1 EP - 5 CY - Jena AN - OPUS4-44572 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Hidde, Gundula A1 - Stockmann, Jörg M. A1 - Weise, Matthias T1 - Ellipsometric imaging of low-contrast surface modifications and depolarization contrast imaging (DCI) of particulate accumulations N2 - Imaging of surfaces regarding topographical, morphological, micro-structural, and chemical features is a key requirement for quality control for the identification of contaminated, degraded, damaged or deliberately modified surface areas vs. clean, virgin, undamaged or unmodified regions. As optical functions may represent any of these changes on the micro- and nano-scale, imaging ellipsometry (IE) is the technique of choice using either intensity, phase, or/and amplitude contrast for visualization of low-contrast surface modifications [1, 2]. Defects or surface and film features whether native or artificial, intended or unintended, avoidable or unavoidable as well as surface pattern are of interest for quality control. In contrast to microscopic techniques operated at normal incidence, ellipsometry as oblique-incidence technique provides improved contrast for vertically nano-scaled add-on or sub-off features such as ultra-thin transparent films, metallic island films, carbon-based thin films, laser modification or laser induced damage, dried stain, cleaning agent or polymeric residue. Two-sample reference techniques, i.e. referenced spectroscopic ellipsometry (RSE) may further increase sensitivity and decrease measurement time. In case of particulate accumulations depolarization contrast imaging (DCI) may improve the lateral resolution beyond the Abbe limit. This has been proven for silica spheres as reference in terms of single particles, particulate accumulations or particulate monolayers and layer stacks. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for reference measurements of particle diameter, particle height, or particulate layer/accumulation thickness. It has been shown that single silica particles of 250 nm in diameter, i.e. at least a factor of 4 better than the lateral resolution limit as of now, can be visualized on even substrates. However, the ellipsometric measurement of particle diameters of this size needs further efforts interpretation. T2 - Workshop Ellipsometry 2018 CY - Chemnitz, Germaný DA - 19.03.2018 KW - Low-contrast surface modifications KW - Particulate distributions KW - Imaging ellipsometry(IE) KW - Depolarization contrast imaging (DCI) PY - 2018 AN - OPUS4-44548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Legall, Herbert A1 - Schwanke, Christoph A1 - Pentzien, Simone A1 - Dittmar, G. A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - X-ray emission as a potential hazard during ultrashort pulse laser material processing N2 - Ultrashort laser pulse micromachining features a high precision. By increasing the repetition rate of the applied laser to several 100 kHz, laser processing becomes quick and cost-effective and make this method attractive for industrial applications. Upon exceeding a critical laser intensity, hard X-ray radiation is generated as a side effect. Even if the emitted X-ray dose per pulse is low, the accumulated X-ray dose becomes significant for high-repetition-rate laser systems so that radiation safety must be considered. The X-ray emission during ultrashort laser processing was investigated for an intensity range up to 2.6*10^14 W/cm2. The investigations were performed with a laser emitting pulses with 925 fs pulse duration, at 1030 nm wavelength and 400 kHz repetition rate. Steel, tungsten, and glass were studied in ambient air. Corresponding X-ray spectra and X-ray dose measurements were presented. Suitable radiation protection strategies were shown. T2 - European Materials Research Society (EMRS) Spring Meeting 2018, Symposium X “Photon-assisted synthesis and processing of materials in nano-microscale” CY - Strasbourg, France DA - 18.06.2018 KW - Laser-induced X-ray emission KW - Ultrashort laser material interaction KW - Femtosecond laser KW - Radiation protection PY - 2018 AN - OPUS4-45382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yildirim, Arda T1 - Liquid Crystals Forming a Columnar Mesophase: Structure, Dynamics and Electric Conductivity N2 - The molecular dynamics and ionic conductivity of ionic liquid crystals (ILCs) forming a columnar mesophase, two linear-shaped tetramethylated guanidinium triflates ILCs having different lengths of alkyl chains, were investigated by a combination of Broadband Dielectric Spectroscopy (BDS) and Specific Heat Spectroscopy (SHS). Three processes were detected by BDS; at low temperature γ-process, at higher temperatures α-process and at even higher temperatures conductivity. The γ-process indicates localized fluctuations, and the α-process designates cooperative fluctuations. Slightly different restrictions were found for conductivity processes of LC536 and LC537 due to the slightly different lengths of alky chains. The conductivity mechanisms in the plastic crystalline and the columnar mesophase have been revealed by BDS and different charge carriers were assigned for the different phases. Furthermore, the cooperative dynamics were also probed by SHS. The cooperative dynamics probed by the different techniques (BDS and SHS) compared, and assigned to the different restrictions on the cooperativity due to the difference in the sensitivity of the techniques. T2 - Seminar Vortrag Technische Universität Berlin CY - Berlin, Germany DA - 28.06.2018 KW - Columnar Liquid Crystals KW - Ionic Liquid Crystals PY - 2018 AN - OPUS4-45383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwanke, Christoph A1 - Legall, Herbert A1 - Pentzien, Simone A1 - Dittmar, G. A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - X-ray emission as a potential hazard during ultrashort pulse laser material processing N2 - Ultrashort laser pulse micromachining features a high precision. By increasing the repetition rate of the applied laser to several 100 kHz, laser processing becomes quick and cost-effective and make this method attractive for industrial applications. Upon exceeding a critical laser intensity, hard X-ray radiation is generated as a side effect. Even if the emitted X-ray dose per pulse is low, the accumulated X-ray dose becomes significant for high-repetition-rate laser systems so that radiation safety must be considered. T2 - Informationsveranstaltung der PTB und des BfS zu Fragen der Bauartzulassungen CY - Bundesministerium für Umwelt, Naturschutz und nukleare Sicherheit, Berlin, Germany DA - 20.06.2018 KW - Laser-induced X-ray emission KW - Ultrashort laser material interaction KW - Femtosecond laser KW - Radiation protection PY - 2018 AN - OPUS4-45364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle A1 - Asadujjaman, Asad A1 - Ahmadi, Vahid T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from monomers with hydrogen-bonding interactions N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and/or 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Invited Talk (Prof. Christine Papadakis) Technische Universität München - Soft Matter Physics CY - Munich, Germany DA - 03.07.2018 KW - Thermoresponsive polymer KW - UCST-type polymer KW - H bonds KW - Diaminopyridine KW - Acrylamide PY - 2018 AN - OPUS4-45423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schönhals, Andreas A1 - Zorn, R. T1 - Elastic scans on highly permeable glassy polynorbornenes N2 - Experimantal Report to proposal 13603: Elastic Scans on Highly Permeable Glassy Polynorbornenes are measured by neutron backscatering and discuused KW - Neutron backscattering KW - Glassy polynorbornenes PY - 2018 SP - 1 EP - 2 CY - Garching (MLZ) AN - OPUS4-45436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans A1 - Weidner, Steffen T1 - High molar mass cyclic poly(L-lactide) via ring-expansion polymerizationwith cyclic dibutyltin bisphenoxides N2 - Two new catalysts (SnNa and SnBi) were prepared from dibutyltin oxide and 2,2′-dihydroxybiphenyl or2,2′dihydroxy(1,1′-binaphtyl). These catalysts enabled rapid polymerizations of L-lactide at 160 or 180 °C in bulk, whereby almost exclusively cyclic polylactides were formed. These polymerizations were free of racemization and yielded pol(L-lactide)s having weight average molecular weights (Mw's) up to 140 000 g mol−1. The Mw's varied little with the Lac/Cat ratio as expected for a ring expansion polymerization (REP). Polymerizations performed in bulk at 140, 120 and 102 °C yielded cyclic polylactides with lower molecular weights. At 102 °C a strong predominance of even-numbered cycles was found with SnNa as catalyst. SnNa can also catalyze alcohol-initiated ROPs yielding linear poly(L-lactide) free of cyclics. KW - MALDI-TOF MS KW - Polylactide KW - Ring-opening Polymerization KW - Cyclization KW - Catalysts PY - 2018 DO - https://doi.org/10.1016/j.eurpolymj.2018.05.036 SN - 0014-3057 SN - 1873-1945 VL - 105 SP - 158 EP - 166 PB - Elsevier Ltd. AN - OPUS4-45439 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Baier, Jennifa A1 - Hidde, Gundula A1 - Sahre, Marion A1 - Weise, Matthias T1 - Particles in PVD-coatings: Imperfection or functional add-on feature? N2 - The application of PVD-coatings ranges from mechanical engineering, i.e. thicker tribological coatings, to precision optics, i.e. thinner optical coatings. For physical vapor deposition (PVD) technologies such as evaporation, sputtering, ion beam assisted/driven deposition, vacuum is a prerequisite for two reasons: at first process-related ones (evaporation source, plasma discharge, and mean free path) and at second coating-related ones (pure, perfect, and dense films). Usually, the goal is a homogenous coating of defined stoichiometry and micro-structure without any imperfection. However, the implementation of micro- or nano-particles may occur accidentally or delibe-rately. Independent of the particle origin, there are two fundamental rules regarding coating functionality: at first, the larger the particle diameter to coating thickness ratio the more affected the functionality of the coating, and at second, the larger the material contrast in terms of the functional feature of interest the more affected the coating performance. Hence, embedded particles have to be avoided for the majority of thin films by all means. The unintended implementation of particles usually results in a malfunction of the coating from the beginning or is at least considered as a weak point of the coating creating a time-dependent defect under service conditions. The intended implementation of particles on surfaces and in coatings may create add-on features, topographic ones and functional ones, however, the facts mentioned hold true. Examples of particle-initiated coating defects are demonstrated in dependence on the origin and the field of application. Strategies for deliberate attachment/embedding of particles on surfaces/in coatings are discussed regarding process compatibility and coating integrity. For industrial applications, both the validation of process compatibility of particle injection and the plasma resistance of particles under vacuum and plasma conditions have to be confirmed. Further points of interest are the homogeneity of particle distribution and the avoidance of particle agglomeration which is still a crucial point for dry dispersed particles. So far, technical applications are limited to PVD hybrid coatings, plasma dispersion coatings are still a challenge except for applications where homogeneity is not required as in case of product authentication. T2 - ICMCTF 2018, International Conference on Metallurgical Coatings and Thin Films CY - San Diego, CA, USA DA - 23.04.2018 KW - PVD-coatings KW - PVD-processes KW - Unintended particle generation KW - Particles as imperfections KW - Deliberate particle implementation KW - Particles as add-on features PY - 2018 AN - OPUS4-44973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zauer, M. A1 - Prinz, Carsten A1 - Adolphs, J. A1 - Emmerling, Franziska A1 - Wagenführ, A. T1 - Sorption surfaces and energies of untreated and thermally modified wood evaluated by means of excess surface work (ESW) N2 - Water vapor sorption surface areas and sorption energies of untreated and thermally modified Norway spruce [Picea abies (L.) Karst.], sycamore maple (Acer pseudoplatanus L.) and European ash (Fraxinus excelcior L.) were investigated by means of dynamic vapor sorption (DVS) measurements and excess surface work (ESW) evaluation method, respectively. Adsorption and desorption experiments in the hygroscopic range and desorption tests from water saturation were conducted. Thermodynamically, ESW is the sum of the surface free energy and the isothermal isobaric work of sorption. From the amount adsorbed in the first Minimum a specific surface area similar to the BET surface area can be obtained. The results show that untreated spruce has a significantly higher specific water vapor Sorption surface and sorption energy compared to both hardwoods maple and ash. Thermal modification of the woods leads to a significant reduction of water vapor Sorption surface and sorption energy. The determined surface area and energy are higher in desorption direction than in adsorption direction, whereby the highest values in Desorption direction from water saturation, especially for maple and ash, were obtained. The surface areas calculated by means of the ESW method are similar to the surface areas calculated by means of the BET method, particularly in adsorption direction. KW - Excess surface work KW - Dynamic vapor sorption KW - Wood KW - BET PY - 2018 DO - https://doi.org/10.1007/s00226-018-1021-2 SN - 1432-5225 SN - 0043-7719 VL - 52 IS - 4 SP - 957 EP - 969 PB - Springer CY - Berlin Heidelberg AN - OPUS4-44975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Weise, Matthias A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Schukar, Vivien A1 - Kormunda2, M. T1 - Multi-functional coatings for optical sensor applications: Surface plasmon resonance & magneto-optical coupling N2 - Multi-functional coatings are a key requirement for surface engineering. General demands are adhesion and long-term stability under service conditions. The modification of surfaces by means of PVD-, ECD- or hybrid processes allows an add-on functionalization of surfaces by a huge diversity of materials with both lateral and vertical micro-/nano-designs. This fact is a prerequisite for micro- and sensor-systems in lab-on-chip and sensor-on-chip technology. Two layer-based sensor principles are presented, i.e. surface plasmon resonance enhanced spectroscopic ellipsometry (SPREE) for detection of hazardous gases and magneto-optical sensors on smart-coated fiber Bragg gratings (FBG) for structural health monitoring (SHM). The interdependence of substrate features, coating properties, and layer design is discussed firstly for gas sensitivity and selectivity of SPREE-sensors and secondly for sensitivity and selectivity of magneto-strictive coatings to mechanical strain or external magnetic fields resulting in an optical displacement of the Bragg wavelength of FBG-sensors. Moreover, generic features such long-term stability, crucial process-related fabrication conditions, and effects of operational and environmental parameters are discussed with respect to the sensor performance. It has been shown that appropriate layer design and adapted selection of layer materials (SnOx/Au, Fe/Ni:SnOx/Au; Ni/NiFe-Cu-Cr) result in improved sensor parameters and may enable new sensor applications. T2 - SVC TechCon 2018 CY - Orlando, FL, USA DA - 05.05.2018 KW - Multi-functional coatings for sensors KW - Surface plasmon resonance enhanced ellipsometry (SPREE) KW - Gas monitoring KW - Magneto-optical coupling (MOC) KW - Structural health monitoring (SHM) PY - 2018 AN - OPUS4-44976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulla, Hannes A1 - Haferkamp, Sebastian A1 - Akhmetova, Irina A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical one-pot syntheses N2 - We present an in situ triple coupling of synchrotron X-ray diffraction with Raman spectroscopy, and thermography to study milling reactions in real time. This combination of methods allows a correlation of the structural evolution with temperature information. The temperature information is crucial for understanding both the thermodynamics and reaction kinetics. The reaction mechanisms of three prototypical mechanochemical syntheses, a cocrystal formation, a C@C bond formation (Knoevenagel condensation), and the formation of a manganese-phosphonate, were elucidated. Trends in the temperature development during milling are identified. The heat of reaction and latent heat of crystallization of the product contribute to the overall temperature increase. A decrease in temperature occurs via release of, for example, water as a byproduct. Solid and liquid intermediates are detected. The influence of the mechanical impact could be separated from temperature effects caused by the reaction. KW - In situ studies KW - Mechanochemistry KW - Raman spectroscopy KW - Thermography KW - X-ray diffraction PY - 2018 DO - https://doi.org/10.1002/anie.201800147 SN - 1433-7851 SN - 1521-3773 VL - 57 IS - 20 SP - 5930 EP - 5933 PB - Wiley-VCH CY - Weinheim AN - OPUS4-44946 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sentker, K. A1 - Zantop, A. W. A1 - Lippmann, M. A1 - Hofmann, T. A1 - Seeck, O. H. A1 - Kityk, A. V. A1 - Yildirim, Arda A1 - Schönhals, Andreas A1 - Mazza, M. G. A1 - Huber, P. T1 - Quantized self-assembly of discotic rings in a liquid crystal confined in nanopores N2 - Disklike molecules with aromatic cores spontaneously stack up in linear columns with high, onedimensional charge carrier mobilities along the columnar axes, making them prominent model systems for functional, self-organized matter.We show by high-resolution optical birefringence and synchrotron-based x-ray diffraction that confining a thermotropic discotic liquid crystal in cylindrical nanopores induces a quantized formation of annular layers consisting of concentric circular bent columns, unknown in the bulk state. Starting from the walls this ring self-assembly propagates layer by layer towards the pore center in the supercooled domain of the bulk isotropic-columnar transition and thus allows one to switch on and off reversibly single, nanosized rings through small temperature variations. By establishing a Gibbs free energy phase diagram we trace the phase transition quantization to the discreteness of the layers’ excess bend deformation energies in comparison to the thermal energy, even for this near room-temperature system. Monte Carlo simulations yielding spatially resolved nematic order parameters, density maps, and bondorientational order parameters corroborate the universality and robustness of the confinement-induced columnar ring formation as well as its quantized nature. KW - Discotic liquid crystals KW - Nanopores PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-440253 DO - https://doi.org/10.1103/PhysRevLett.120.067801 SN - ‎0031-9007 SN - 1079-7114 VL - 120 IS - 6 SP - 067801-1 EP - 067801-7 PB - American Physical Society AN - OPUS4-44025 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Saloga, Patrick E. J. T1 - Messdatenauswertung mittels Origin in der Nanopartikelanalyse N2 - Die Anwendung der Software Origin zur Datenauswertung in der Nanopartikelanalyse wird anhand eines Beispiels vom Importieren der Daten über deren Verarbeitung bis zur graphischen Ausgabe demonstriert. T2 - ADDITIVE Origin Anwendertage 2018 CY - Berlin, Germany DA - 12.03.2018 KW - Silbernanopartikel KW - Origin KW - SAXS PY - 2018 AN - OPUS4-44458 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas A1 - Madkour, Sherif A1 - Szymoniak, Paulina T1 - Unraveling the dynamics of thin films of a miscible PVME/PS blend N2 - Dielectric spectroscopy (BDS) was employed to investigate the dynamics of thin films (7 – 200 nm) of a Poly (vinyl methyl ether) (PVME) / Polystyrene (PS) blend (50:50 wt%). For the BDS measurements Nano-Structured Capacitors (NSC) were employed, where films have a free surface. This method was applied for film thicknesses up to 36 nm. Thicker films were prepared between Crossed Electrodes Capacitors (CEC). The spectra of the films showed multiple processes. The first process was assigned to the -relaxation of a bulk-like layer. For films measured by NSC, its rates were higher compared to that of the bulk blend. This behavior was related to a PVME-rich free-surface layer. A second process was observed for films measured by CEC (process X) and the 36 nm film measured by NSC (process X2). This process was assigned to fluctuations of PVME constraint by PS. Its activation energy was found to be thickness dependent, due to the evidenced thickness dependency of the compositional heterogeneity. Finally, a third process with an activated temperature-dependence was observed for all films measured by NSC (process X1). It resembled the molecular fluctuations in an adsorbed layer found for films of pure PVME. T2 - Anual Meeting of the American Physical Society CY - Los Angeles, CA, USA DA - 05.03.2018 KW - Thin polymeric films PY - 2018 AN - OPUS4-44414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Terkawi, Abdal-Azim A1 - Scholz, G. A1 - Prinz, Carsten A1 - Zimathies, Annett A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - Hydrated and dehydrated Ca-coordination polymers based on benzene-dicarboxylates: mechanochemical synthesis, structure refinement, and spectroscopic characterization N2 - A series of Ca-based coordination polymers were prepared mechanochemically by milling Ca(OH)2 with phthalic acid (H2oBDC), isophthalic acid (H2mBDC), and terephthalic acid (H2pBDC). The hydrated compounds [Ca(oBDC)(H2O)], [Ca(mBDC)(H2O)3.4], and [Ca(pBDC)(H2O)3] were prepared for the first time via mechanochemical routes. The refined structures were validated by extended X-ray absorption data. The new dehydrated compound [Ca(oBDC)] (1-H2O), obtained after the thermal post-treatment of 1 in a reversible phase transition process, was determined ab initio based on the powder X-ray diffraction (PXRD) data. The materials were thoroughly characterized using elemental analysis, thermal analysis, and spectroscopic methods: magic-angle spinning NMR and attenuated total reflection-infrared spectroscopy. The specific surface areas and sorption properties of the hydrated and dehydrated samples were determined using the isotherms of gas sorption and dynamic vapor sorption measurements. KW - Mechanochemistry KW - XRD PY - 2018 UR - http://pubs.rsc.org/en/content/articlehtml/2017/ce/c7ce01906h DO - https://doi.org/10.1039/C7CE01906H VL - 20 SP - 946 EP - 961 PB - Royal Society of Chemistry AN - OPUS4-44440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Controlled self-assembly of Janus dendrimers via microfluidics N2 - Vesicles self-assembled in water from natural and synthetic phospholipids (liposomes), amphiphilic block copolymers (polymersomes), and more recently amphiphilic Janus dendrimers (dendrimersomes) -5 as hollow soft structures in the nano size regime have attracted increasing interest as they can mimic primitive and contemporary biological membranes, and can be configured into biomimetic nanocapsules with application in nanomedicine such as gene, proteins and drug carriers or theranostics. Compared to other amphiphilic structures, the molecular structure of Janus dendrimers can be precisely controlled: by using the vast range of tools from organic chemistry their size, architecture, density, generation as well as the number of end groups of the individual dendrons can be modified as desired. Unfortunately, the controlled production of supramolecular aggregates made thereof is still a challenging task. Conventional batch-based techniques such as the solvent injection method or the film hydration method typically go along with a lack of control over self assembly/mixing and thus over size, morphology and size distribution of the vesicles. The micromixer technology is a promising method for the controlled preparation of supramolecular assemblies as it allows control of mixing at microscale level. In addition, such microfluidic systems benefit from a high mixing efficiency, a low mixing time as well as from a reproducible and continuous production of soft nanoparticles. Herein, we report on the microfluidic-controlled self-assembly of Janus dendrimers as dendrimersomes and the impact of the mixing parameters on the self-assembly process. T2 - Invited talk Leibniz Institute of Polymer Research Dresden (IPF) CY - Dresden, Germany DA - 08.03.2018 KW - Vesicles KW - Janus dendrimers KW - Microfluidics PY - 2018 AN - OPUS4-44441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Building macromolecular mimetics of cell constituents N2 - One of the holy grails in chemistry is to reconstitute some of life’s functions with or within synthetic materials. In this contribution, we demonstrate that “simple” macromolecular architectures such as dendritic amphiphiles, Janus dendrimers, thermoresponsive and hybrid organic-inorganic (co)polymers enable to mimic some of the functions of proteins for biomineralization, natural bactericides, biological membranes or the stimuli-responsive cytoskeleton. T2 - Chemiedozententagung 2018 CY - Jena, Germany DA - 05.03.2018 KW - UCST-type polymers KW - Bioinspiration KW - Thermoresponsive polymers PY - 2018 AN - OPUS4-44442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lange, Thorid A1 - Hidde, Gundula A1 - Beck, Uwe A1 - Naumann, F. A1 - Kärkkänen, I. A1 - Gargouri, H. T1 - HARFE: Haftfestigkeit Reproduzierbarkeit Festigkeit „Nanoskalige Haftvermittler zur Erhöhung der Haft- bzw. Klebfestigkeit unter Verwendung von ALD-Hybridprozessen“ N2 - Das Poster „HARFE: Haftfestigkeit Reproduzierbarkeit Festigkeit“ widmet sich den nanoskaligen Haftvermittlern zur Erhöhung der Haft- bzw. Klebfestigkeit unter Verwendung von ALD-Hybridprozessen. T2 - Netzwerksymposium “Schützen und Veredeln von Oberflächen”, Wildau CY - TH Wildau, Germany DA - 01.03.2018 KW - Verbundfestigkeit KW - Oberflächenenergie KW - ALD-Beschichtung PY - 2018 AN - OPUS4-44399 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gawek, Marcel A1 - Madkour, Sherif A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth Kinetics and Molecular Mobility of Irreversibly Adsorbed Layers in Thin Polymer Films N2 - In well-annealed thin polymer films, with non-repulsive polymer/substrate interactions, an irreversibly adsorbed layer is expected to form. These adsorbed layers have shown great potential for technological applications. However, their growth kinetics and molecular dynamics are still not fully understood. This is partially due to the hard accessibility of these layers in thin films. Here, the irreversibly adsorbed layers of homopolymer thin films are revealed by solvent-leaching experiments. First, the growth kinetics of these layers is investigated as a function of annealing times and original film thickness. The thickness, topography and quality of the adsorbed layer is controlled with Atomic Force Microscopy (AFM). Secondly, the molecular mobility of the adsorbed layer is investigated with Broadband Dielectric Spectroscopy (BDS). A recently developed nanostructured capacitor is employed to measure the adsorbed layers with a free surface layer. The results are quantitatively compared and discussed with respect to recently published work. T2 - Meeting of the American Physical Society CY - Los Angeles, CA, USA DA - 05.03.2018 KW - Thin polymeric films KW - Adsorbed layer PY - 2018 AN - OPUS4-44488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gawek, Marcel A1 - Madkour, Sherif A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth Kinetics and Molecular Mobility of Irreversibly Adsorbed Layers in Thin Polymer Films N2 - In well-annealed thin polymer films, with non-repulsive polymer/substrate interactions, an irreversibly adsorbed layer is expected to form. These adsorbed layers have shown great potential for technological applications. However, their growth kinetics and molecular dynamics are still not fully understood. This is partially due to the hard accessibility of these layers in thin films. Here, the irreversibly adsorbed layers of homopolymer thin films are revealed by solvent-leaching experiments. First, the growth kinetics of these layers is investigated as a function of annealing times and original film thickness. The thickness, topography and quality of the adsorbed layer is controlled with Atomic Force Microscopy (AFM). Secondly, the molecular mobility of the adsorbed layer is investigated with Broadband Dielectric Spectroscopy (BDS). A recently developed nanostructured capacitor is employed to measure the adsorbed layers with a free surface layer. The results are quantitatively compared and discussed with respect to recently published work. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Thin polymeric films KW - Dielectric spectroscopy PY - 2018 AN - OPUS4-44489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas A1 - Yin, Huajie A1 - Konnerts, Nora A1 - Böhning, Martin T1 - Molecular mobility and physical aging of polymers with intrinsic microporosity as revealed by dielectric spectroscopy N2 - The dielectric properties of different polymers with intrinsic microporosity are investigated by braodband dielectric spectroscopy. The results are discussed with regard to the structure T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Polymers with intrinsic microporosity KW - Gas separation membranes KW - Dielectric spectroscopy PY - 2018 AN - OPUS4-44490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Szymoniak, Paulina A1 - Madkour, Sherif A1 - Schönhals, Andreas T1 - Unexpected behavior of thin PVME/PS blend films investigated by specific heat spectroscopy N2 - The structure and molecular dynamics of thin polymer films are of topical interest of soft matter-physics. Commonly, spatial structural heterogeneities of 1D confined thin films (surface, bulk-like and adsorbed layer), are expected to alter the glassy dynamics, compared to the bulk. Here, Specific Heat Spectroscopy (SHS) was used, to investigate the glassy dynamics of thin films of an asymmetric miscible PVME/PS 25/75 wt% blend. SHS measurements showed a non-monotonous thickness dependence of the dynamic Tg, on the contrary to the previously investigated PVME/PS 50/50 wt%. For PVME/PS 25/75 wt% thin films (> 30 nm), due to the presence of PVME-rich adsorbed and surface layers, the bulk-like layer experienced a thickness dependent increase of PS concentration. This led to a systematic increase of dynamic Tg. Further decrease of the film thickness (< 30 nm), resulted in a decrease of dynamic Tg, ascribed to the influence of the surface layer, which has a high molecular mobility. This is the first study, which shows deviations of dynamic Tg of thin films, compared to the bulk, resulting from the counterbalance of the free surface and adsorbed layer. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Thin polymeric films PY - 2018 AN - OPUS4-44494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas A1 - Szymoniak, Paulina A1 - Madkour, Sherif T1 - Nano-sized Relaxation Spectroscopy of Miscible PVME/PS Blend Thin Films N2 - The moleculat dynamics of ultra thin films of polystyrene/poly(vinyl methyl ether) blends as revealed by nanosized specific heat and dielectric spectroscopy is discussed. T2 - Viscous liquids and the glass transition XV CY - Søminestationen, Holbæk, Denmark DA - 21.06.2018 KW - Thin polymeric films KW - Dielectric spectroscopy KW - Specific heat spectroscopx PY - 2018 AN - OPUS4-45280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle A1 - Taabache, Soraya A1 - Bertin, Annabelle T1 - Dendritic Amphiphiles as Macromolecular Mimetics of Cellular Constituents N2 - One of the holy grails in chemistry is to reconstruct some of life’s functions within synthetic materials. In this contribution, we demonstrate that “simple” macromolecular architectures such as dendritic amphiphiles, Janus dendrimers, thermoresponsive and hybrid organic-inorganic (co)polymers enable to mimic some of the functions of proteins for biomineralization, natural bactericides, biological membranes or the stimuli-responsive cytoskeleton. T2 - Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) - Dpt. des Matériaux Organiques (DMO), invited talk by Prof. Laurent Douce CY - Strasbourg, France DA - 09.02.2018 KW - Dendritic amphiphile KW - Antibacterial properties KW - Vesicles KW - Microfluidic PY - 2018 AN - OPUS4-44146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Madkour, Sherif A1 - Gawek, Marcel A1 - Schönhals, Andreas T1 - Determination of the glass transition region of thin PVME films by means of spectroscopic ellipsometry N2 - In this presentation, we report on the Determination of the glass transition temperature of thin layers of Polyvinylmethylether (PVME) depending on the thickness of the polymer layer. The glass Transition of thin polymer layers is currently under much investigation due to the nano-confinement effects proposed to appear in dependence on the layer thicknesses in the nm range. The properties of the polymer, the temperature range, as well as the thicknesses range of the polymer layers pose a serious challenge to the investigation by means of spectroscopic ellipsometry. By careful choice of experimental parameters, we were able to investigate the thickness change by temperature of PVME layers in the range between 2 and 300 nm and in the temperature range between 200 K and 340 K. By optimizing the analysis process, we were able to determine Tg values within this parameter range with sufficient accuracy to investigate the Tg change due to confinement effects. Alongside the change of position of the glass transition with thickness, we discuss the details of the ellipsometric analysis and its implications for the resulting thermal properties of the thin polymer layers as well as the accuracy of the Tg value with respect to the method used in the analysis process. T2 - Workshop Ellipsometry 2018 CY - Chemnitz, Germany DA - 19.03.2018 KW - Polymers KW - PVME KW - Temperature dependent ellipsometry KW - Glass transition PY - 2018 AN - OPUS4-44672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Rosu, D.-M. A1 - Beck, Uwe T1 - Calibration samples and the GUM-compliant determination of uncertainties in ellipsometry N2 - Ellipsometry is well known as a highly sensitive and reproducible surface analysis technique. However, in a context of metrological applications, the most important property of a measurement process is accuracy, relying on statistical precision, (reproducibility) and trueness (in an absolute sense versus a given standard). The latter is much more difficult to achieve. In this presentation, we discuss the possibility of establishing ellipsometry in a diverse metrological landscape by means of defining standard procedures and best practice methodologies for the measurement and for calibration purposes. The most important task of this approach is to determine the model-inherent uncertainty, originating from parameter coupling. We achieve this by means of sensitivity analysis of the parameters resulting from the fit process. We discuss the definition of reference materials by which accuracy can be made available for ellipsometry, passed along between ellipsometry laboratories and for other measurement techniques. The determination of uncertainty is presented in this work for a number of examples involving difficult analysis models employed for samples from different production environments. We present a standardization initiative with the goal to disseminate this work into an international standard alongside an inter-laboratory study comparing the results for complex samples gained by laboratories with different instrumentation. We also present the results gained within EURAMET projects focused on the metrology of materials with strong non-idealities used in photovoltaics and other energy technology. T2 - Workshop Ellipsometry 2018 CY - Chemnitz, Germany DA - 19.03.2018 KW - Ellipsometric metrology KW - Reference samples KW - Reference procedures KW - Standardization PY - 2018 AN - OPUS4-44674 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yin, Huajie A1 - Chua, Y. Z. A1 - Yang, B. A1 - Schick, C. A1 - Harrison, W. A1 - Budd, P. A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - First clear cut experimental evidence for a glass transition in a polymer with intrinsic microporosity: PIM-1 N2 - Polymers with intrinsic microporosity (PIMs) represent a novel, innovative class of materials with great potential in various applications from high-performance gas separation membranes to electronic devices. Here for the first time, for PIM-1, as the archetypal PIM, fast scanning calorimetry provides definitive evidence for a glass transition (Tg=715 K, heating rate 3·10^4 K/s) by decoupling the time-scales responsible for glass transition and decomposition. As the rigid molecular structure of PIM-1 prevents any conformational changes, small-scale bend and flex fluctuations must be considered the origin of its glass transition. This result has strong implications for the fundamental understanding of the glass transition and for the physical aging of PIMs and other complex polymers, both topical problems of materials science. KW - Polymers with intrinsic microporosity KW - Fast Scanning Calorimetry PY - 2018 DO - https://doi.org/10.1021/acs.jpclett.8b00422 SN - 1948-7185 VL - 9 IS - 8 SP - 2003 EP - 2008 PB - ACS AN - OPUS4-44683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas A1 - Zorn, R. A1 - Böhning, Martin T1 - Vibrational density of states and molecular mobility in a polymer with intrinsic microporosity PIM-1 as revealed by inelastic neutron scattering N2 - Polymers with intrinsic microporosity are promising candidates for the active separation layer in gas separation membranes. Here, by means of inelastic neutron scattering, the vibrational density of states (VDOS) and the molecular mobility were investigated for PIM-1, the prototypical polymer with intrinsic microporosity. The results are compared to data measured for a more conventional high-performance polyimide used in gas separation membranes (Matrimid). The measured data show the characteristic low frequency excess contribution to the VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. In comparison to the Boson peak of Matrimid, that of PIM-1 is shifted to lower frequencies. This shift is discussed considering the microporous, sponge-like structure of PIM-1 as providing a higher compressibility at the molecular scale than for conventional polymers. Elastic fixed window scans were measured on a neutron backscattering spectrometer to have an overview about the molecular dynamics at a time scale of ca. 1 ns. The temperature dependence of the estimated mean squared displacement shows a step-like increase in the temperature range from 100 K to 250 K indicating the onset of some molecular mobility. The nature of this motional process was analyzed in detail by quasielastic neutron scattering where the data are discussed with regard to both the q- and the temperature dependence. T2 - QENS/WINWS 2018 CY - Hong Kong, China DA - 17.07.2018 KW - Polymers with intrinic microporosity KW - Quasielastic neutron scattering PY - 2018 AN - OPUS4-45534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Schönhals, Andreas A1 - Frick, B. A1 - Zorn, R. ED - Kremer, Friedrich ED - Loidl, Alois T1 - The scaling of the molecular dynamics of liquid crystals as revealed by broadband dielectric, specific heat, and neutron spectroscopy N2 - A combination of different complementary methods is employed to investigate scaling of the molecular dynamics of two different liquid crystals. Each method is sensitive to different kind of fluctuations and provides therefore a different window to look at the molecular dynamics. In detail, broadband dielectric spectroscopy is combined with specific heat spectroscopy and neutron scattering. As systems the nematic liquid crystal E7 and a discotic liquid crystalline pyrene are considered. First of all it was proven that both systems show all peculiarities which are characteristic for glassy dynamics and the glassy state. Especially for the nematic liquid crystal E7 it could be unambiguously shown by a combination of dielectric and specific heat spectroscopy that the tumbling mode is the underlying motional process responsible for glassy dynamics. Dielectric investigations on the discotic liquid crystalline pyrene reveal that at the phase transition from the plastic crystalline to the hexagonal columnar liquid crystalline phase the molecular dynamics changes from a more strong to fragile temperature dependence of the relaxation rates. Moreover a combination of results obtained by specific heat spectroscopy with structural methods allows an estimation of the length scale relevant for the glass transition. KW - Broadband dielectric spectroscopy KW - Specific heat spectroscopy KW - Rod-like liquid crystals KW - Discotic liquid crystals PY - 2018 UR - https://link.springer.com/content/pdf/10.1007%2F978-3-319-72706-6.pdf SN - 978-3-319-72705-9 SN - 978-3-319-72706-6 DO - https://doi.org/10.1007/978-3-319-72706-6_9 SN - 2190-930X SN - 2190-9318 SP - 279 EP - 306 PB - Springer International publishing AG CY - Cham, Switzerland ET - 1. AN - OPUS4-45624 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piedade, M. F. M. A1 - Joseph, A. A1 - Alves, J. R. A1 - Bernardes, C. E. S. A1 - Emmerling, Franziska A1 - Minas da Piedade, M. E. T1 - Crystal Engineering through Solvent Mediated Control of Molecular Conformation: The Case of 5-Hydroxynicotinic Acid N2 - The importance of molecular conformation for polymorphism and its repercussions in terms of tight control over the industrial production of crystalline organic materials with highly reproducible physicochemical properties has long been recognized. Efforts to understand how a crystallization solvent can direct the formation of a polymorph containing a specific molecular conformation are, however, relatively scarce. Nicotinic acid (NA) and its hydroxyl derivatives (2-, 4-, 5-, and 6-hydroxynicotinic acids) are very good models for such studies. Indeed, regardless of the solvent, NA always crystallizes as a single polymorph with the molecule in the same neutral conformation. In contrast, the hydroxyl derivatives are prone to polymorphism and solvate formation and, depending on the crystallization conditions, the molecules in the crystal lattice can exhibit hydroxyl, oxo, or zwitterionic conformations. The present study focused on 5-hydroxynicotinicacid (5HNA) shows that by judicious selection of the solvent it is possible to obtain 1:1 solvates, where solvation memory is not completely lost and the tautomer preferred in solution persists in the crystalline state: zwitterionic in 5HNA·H2O and neutral in 5HNA·DMSO. Nevertheless, upon thermal desolvation the obtained materials evolve to the same unsolvated form where the molecule is in a zwitterionic conformation. The structures of 5HNA·H2O and 5HNA·DMSO obtained from single crystal-ray diffraction are discussed and compared with that of 5HNA solved from powder data. The energetics of the dehydration/desolvation process was also fully characterized by thermogravimetry (TG), differential scanning calorimetry (DSC) and Calvet microcalorimetry. T2 - BACG 2018 CY - Limerick, Ireland DA - 20.06.2018 KW - Crystal Engineering KW - 5-hydroxynicotinic acid KW - Molecular Conformation PY - 2018 AN - OPUS4-45519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -