TY - CONF A1 - Kolmangadi, Mohamed Aejaz A1 - Schönhals, Andreas T1 - Suppressed Transition and Dynamic self-asembly of ionic superdiscs in cylindrical nanochannels N2 - Liquid crystalline mesophases in nanoconfinement exhibit intriguing phase transition behaviors and relaxation dynamics. Here, we investigate the molecular mobility and electrical conductivity of a columnar ionic liquid crystal confined in self-ordered nanoporous alumina oxide membranes of pore size ranging from 180 nm down to 25 nm. We use nano-broadband dielectric spectroscopy (BDS) and calorimetry to study the dynamics and phase behavior. Calorimetric investigation reveals a complete suppression of the columnar – isotropic transition, while the plastic crystalline – columnar transition temperature decreases with inverse pore size and deviates from the Gibbs – Thomson equation. For the bulk case, BDS detects two relaxation modes in the crystalline phase, the γ relaxation and the α1 relaxation, and two relaxation modes in the columnar phase, the α2 and α3 relaxation. All relaxation modes slow down for the confined case compared to the bulk. However, a new relaxation mode reflecting the interfacial layer emerges for the 80 and 25 nm. We discuss the possible molecular origins of the different relaxation modes observed. For the bulk ILC, a clear jump of 4 orders of magnitude in the absolute values of DC conductivity occurs at the transition from the plastic crystalline to hexagonal columnar phase, for the confined ILC, this transition is smooth. DC conductivity is reduced for the confined case, except for the 25nm, where the values are similar to the bulk. T2 - APS March Meeting 2023 CY - Las Vegas, NV, USA DA - 05.03.2023 KW - Ionic Liquid crystals KW - Nanoconfinement KW - Conductivity PY - 2023 AN - OPUS4-57342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolmangadi, Mohamed Aejaz A1 - Szymoniak, Paulina A1 - Schönhals, Andreas A1 - Smales, Glen Jacob A1 - Böhning, Martin T1 - Molecular Dynamics of Janus Polynorbornenes: Glass Transitions and Nanophase separation N2 - We report the dielectric and calorimetric investigations of an homologous series of Janus polynorbornenes with rigid main backbone and flexible -Si(OR)3 side groups, of differing length alkyl chains (R = Propyl, Butyl, Hexyl, Octyl, Decyl). Dielectric dispersion reveals two active processes at low temperatures, denoted as β- and α- relaxation. The former can be assigned to localized fluctuations, whilst the latter relates to the glassy dynamics of the flexible -Si(OR)3 side groups, that creates a nanophase separation in both the alkyl chain rich and backbone rich domains. Temperature modulated DSC measurements and X-ray scattering experiment confirm the nanophase separation. Fast Scanning Calorimetry employing both fast heating and cooling rates detects the glass transition temperatures of the backbone rich domains, which are beyond or near to their degradation temperatures in terms of conventional DSC. The cooperative length scale of glass transition and the size of the alkyl chain rich domains increases with chain length. Alongside these results, a significant conductivity contribution was observed for all Poly(tricyclononenes) with Si(OR)3 side groups, which is interpreted in terms of a percolation model. T2 - Chemical Engg Seminar CY - Columbia University, NY, USA DA - 14.03.2023 KW - Glass transition KW - Conductivity KW - Fast Scanning Calorimetry KW - Dynamics PY - 2023 AN - OPUS4-57343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolmangadi, Mohamed Aejaz A1 - Schönhals, Andreas A1 - Li, Z. A1 - Huber, P. T1 - Suppressed Transition and Dynamic self-asembly of ionic superdiscs in cylindrical nanochannels N2 - Liquid crystalline mesophases in nanoconfinement exhibit intriguing phase transition behaviors and relaxation dynamics. Here, we investigate the molecular mobility and electrical conductivity of a columnar ionic liquid crystal confined in self-ordered nanoporous alumina oxide membranes of pore size ranging from 180 nm down to 25 nm. We use nano-broadband dielectric spectroscopy (BDS) and calorimetry to study the dynamics and phase behavior. Calorimetric investigation reveals a complete suppression of the columnar – isotropic transition, while the plastic crystalline – columnar transition temperature decreases with inverse pore size and deviates from the Gibbs – Thomson equation. For the bulk case, BDS detects two relaxation modes in the crystalline phase, the γ relaxation and the α1 relaxation, and two relaxation modes in the columnar phase, the α2 and α3 relaxation. All relaxation modes slow down for the confined case compared to the bulk. However, a new relaxation mode reflecting the interfacial layer emerges for the 80 and 25 nm. We discuss the possible molecular origins of the different relaxation modes observed. For the bulk ILC, a clear jump of 4 orders of magnitude in the absolute values of DC conductivity occurs at the transition from the plastic crystalline to hexagonal columnar phase, for the confined ILC, this transition is smooth. DC conductivity is reduced for the confined case, except for the 25nm, where the values are similar to the bulk. T2 - DPG Spring Meet 2023 CY - Dresden, Germany DA - 26.03.2023 KW - Ionic Liquid crystals KW - Nanoconfinement KW - Conductivity PY - 2023 AN - OPUS4-57345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feltin, N. A1 - Crouzier, L. A1 - Delvallée, A. A1 - Pellegrino, F A1 - Maurino, V. A1 - Bartczak, D. A1 - Goenaga-Infante, H. A1 - Taché, O. A1 - Marguet, S. A1 - Testard, F. A1 - Artous, S. A1 - Saint-Antonin, F. A1 - Salzmann, Christoph A1 - Deumer, J. A1 - Gollwitzer, C. A1 - Koops, R. A1 - Sebaïhi, N. A1 - Fontanges, R. A1 - Neuwirth, M. A1 - Bergmann, D. A1 - Hüser, D. A1 - Klein, T. A1 - Hodoroaba, Vasile-Dan T1 - Metrological Protocols for Reaching Reliable and SI-Traceable Size Results for Multi-Modal and Complexly Shaped Reference Nanoparticles N2 - The study described in this paper was conducted in the framework of the European nPSize project (EMPIR program) with the main objective of proposing new reference certified nanomaterials for the market in order to improve the reliability and traceability of nanoparticle size measurements. For this purpose, bimodal populations as well as complexly shaped nanoparticles (bipyramids, cubes, and rods) were synthesized. An inter-laboratory comparison was organized for comparing the size measurements of the selected nanoparticle samples performed with electron microscopy (TEM, SEM, and TSEM), scanning probe microscopy (AFM), or small-angle X-ray scattering (SAXS). The results demonstrate good consistency of the measured size by the different techniques in cases where special care was taken for sample preparation, instrument calibration, and the clear definition of the measurand. For each characterization method, the calibration process is described and a semi-quantitative table grouping the main error sources is proposed for estimating the uncertainties associated with the measurements. Regarding microscopy-based techniques applied to complexly shaped nanoparticles, data dispersion can be observed when the size measurements are affected by the orientation of the nanoparticles on the substrate. For the most complex materials, hybrid approaches combining several complementary techniques were tested, with the outcome being that the reliability of the size results was improved. KW - Certified reference nanomaterials KW - Traceable nanoparticle size measurements; KW - Hybrid metrology KW - Scanning probe microscopy KW - Small-angle X-ray scattering KW - Electron microscopy PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571902 DO - https://doi.org/10.3390/nano13060993 SN - 2079-4991 VL - 13 IS - 6 - Special Issue "Identification and Quantification of Nanomaterials" SP - 1 EP - 25 PB - MDPI CY - Basel, CH AN - OPUS4-57190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Omar, Hassan A1 - Szymoniak, Paulina A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Probing Nanoscale Relaxation Behavior in Thin Polymer Films N2 - The investigations into the complicated effects of film thickness on bulk properties of thin polymer films has yielded conflicting results. The reduction in molecular mobility, and with it an increase in the glass transition temperature, for thin films of poly (bisphenol A carbonate) (PBAC) was assigned to the formation of an adsorbed layer. The adsorbed layer was obtained by washing away the loosely bounded chains using a good solvent. Next, using atomic force microscopy (AFM), the thickness of each sample was measured after annealing for various times at three different annealing temperatures. The growth of this adsorbed layer was shown to deviate from the previously reported 2-step mechanism seen for other polymers. For PBAC, after very long annealing times at high temperatures the thin films were dewetted, where segments of the adsorbed layer were removed from the substrate. T2 - Royal Society of Chemistry (RSC) Poster CY - Online meeting DA - 28.02.2023 KW - Thin films KW - Adsorbed Layer KW - Broadband dielectric spectroscopy KW - Atomic force microscopy KW - Growth Kinetics PY - 2023 AN - OPUS4-57196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - VIDEO A1 - Pauw, Brian Richard T1 - "Ultima Ratio": Multi-scale, high-resolution 3D-FFT scattering pattern simulations N2 - This talk highlights a proof-of-concept that demonstrates the ability to calculate high-resolution Fourier transforms. These can be combined with multi-scale modeling to simulate scattering over a wide range, from small-angle scattering to XRD and PDF. The preprint documenting this is available on the ArXiv here: https://doi.org/10.48550/arXiv.2303.13435 The Jupyter notebook, VASP calculation details and MOUSE measured scattering patterns are available from this Zenodo repository: https://dx.doi.org/10.5281/zenodo.7764045 KW - Video KW - Simulation KW - High-resolution KW - Fourier Transform KW - 3D FFT KW - Nanomaterial KW - Metal organic framework KW - MOF KW - SAXS KW - XRD KW - PDF KW - X-ray diffraction KW - Pair distribution function KW - Small-angle X-ray scattering PY - 2023 UR - https://www.youtube.com/watch?v=lEApkOqR5e8 PB - YouTube, LLC CY - San Bruno, CA, USA AN - OPUS4-57212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob T1 - Electric Safety Interlock N2 - This interlock is designed to prevent electrical shock from high voltage (>60V) equipment. While the general safety interlock can be generically applied, this particular example employs an external vacuum-activated switch. It is for safeguarding human operations inside a vacuum sample chamber while the chamber doors are open. The circuit is closed (output is active) when a sufficient level of vacuum is reached, i.e. when all accessible openings are necessarily closed. The initial application is to interrupt power to a 220V, 250W heating cartridge (itself mounted inside a small sample holder with potentially exposed contacts) when the sample chamber is open. The external circuit can be modified to use different interlock mechanisms as needed. Note that the external interlock circuit is only a single circuit (with two signal lines) and thus is not protected against external shorts. To accomodate a range of safety interlocks, the 4-pin M12 connector is wired as follows: Pin 1 (Brown): +24V for power supply, max current 0.6A Pin 2 (White): Safety interlock system signal 1 (0 or 24V) Pin 3 (Blue) : Safety interlock system signal 2 (0 or 24V) Pin 4 (Black): 0V for power supply The safety is interlocked (output active) when both signal pins are set high (24V), with sufficient current to activate the two relays. Pin 1 and 4 can be used to power safety hardware (such as light curtains or proximity detectors) with 24VDC up to a current of 0.6A. A larger power supply can be installed when higher currents are needed, while staying within the current limits imposed by the wiring cross-section. KW - Electric Safety Interlock KW - MOUSE KW - 60-230V PY - 2023 DO - https://doi.org/10.6084/m9.figshare.22265920.v1 PB - Digital Science CY - Cambridge, MA, USA AN - OPUS4-57138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sun, Yijuan A1 - Gawlitza, Kornelia A1 - Valderrey, Virginia A1 - Bell, Jérémy A1 - Rurack, Knut T1 - Polymerizable BODIPY probe crosslinker for the molecularly imprinted polymer-based detection of organic carboxylates via fluorescence N2 - This contribution reports the development of a polymerizable BODIPY-type fluorescent probe targeting small-molecule carboxylates for incorporation into molecularly imprinted polymers (MIPs). The design of the probe crosslinker includes a urea recognition site p-conjugated to the 3-position of the BODIPY core and two methacrylate moieties. Titration experiments with a carboxylate-expressing antibiotic, levofloxacin (LEVO), showed a blue shift of the absorption band as well as a broadening and decrease in emission, attributed to hydrogen bonding between the probe’s urea group and the carboxylate group of the antibiotic. Using this probe crosslinker, core–shell particles with a silica core and a thin MIP shell were prepared for the detection of LEVO. The MIP exhibited highly selective recognition of LEVO, with an imprinting factor of 18.1 compared to the non-imprinted polymer. Transmission electron microscopy confirmed the core–shell structure and spectroscopic studies revealed that the receptor’s positioning leads to a unique perturbation of the polymethinic character of the BODIPY chromophore, entailing the favourable responses. These features are fully preserved in the MIP, whereas no such response was observed for competitors such as ampicillin. The sensory particles allowed to detect LEVO down to submicromolar concentrations in dioxane. We have developed here for the first time a BODIPY probe for organic carboxylates and incorporated it into polymers using the imprinting technique, paving the way for BODIPY-type fluorescent MIP sensors. KW - Fluorescence KW - BODIPY probe KW - Molecularly Imprinted Polymers KW - Sensor Materials KW - Dyes KW - Water analysis KW - Advanced materials PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598629 DO - https://doi.org/10.1039/D3MA00476G SP - 1 EP - 11 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59862 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo T1 - Navigating the Nanoworld: Understanding Materials Properties with the Transmission Electron Microscope N2 - The field of materials science is defined as “the study of the properties of solid materials and how those properties are determined by a material’s composition and structure.”. Many –if not most– of the materials that are produced nowadays owe their properties to structures engineered down to the nanoscopic level. This need has been partly realized thanks to the understanding of materials’ building blocks via characterization techniques that reach this level of resolution. Transmission electron microscopy, since its first implementation in the early 1930s (in Berlin), has been implemented to achieve imaging –and spectral– analysis at lateral resolutions down to the atomic level. In this contribution, a series of practical examples will be presented, where applied materials are characterized by a range of transmission electron microscopy techniques to understand structural and functional properties of a wide range of materials. Among these materials examples will be presented on structural conventionally and additively manufactured metallic alloys, high entropy alloys, dissimilar aluminum-to-steel welds, magnetic nanoparticles, ceramic coatings, high temperature oxidation products. Addressed will be either the effect of processing route or that of the exposure to experimental conditions similar to those found in the respective intended applications. T2 - UA/UAB/UAH MSE Graduate Seminar CY - Online meeting DA - 19.01.2022 KW - Transmission electron microscopy (TEM) KW - Characterization KW - Microstructure KW - 3D PY - 2022 AN - OPUS4-54238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Probenpräparation für AFM-basierte Untersuchungsverfahren N2 - Adapted and advanced sample preparation of semiconductor layer systems with the focused ion beam for AFM-based test methods N2 - Der vorliegende Vortrag gibt einen Überblick über Probenpräparationen mit der Focused Ion Beam (FIB) für AFM-basierte Untersuchungsverfahren. Anhand zweier Beispiele wird gezeigt, wie ionenstrahlpolierte Lamellen aus Halbleiter-Schichtsystemen elektrisch leitfähig auf Substrate platziert werden, so dass in-situ und in-operando Messungen mit Scanning Microwave Microscope (SMM) bzw. Spectroscopic infrared scanning near-field optical microscope (IR-SNOM) durchgeführt werden können. T2 - 15. Berlin-Brandenburger Präparatorentreffen CY - Potsdam/Golm, Germany DA - 11.04.2019 KW - Focused Ion Beam KW - AFM based test methods KW - Sample preparation KW - Semiconductor materials KW - Layer system PY - 2019 AN - OPUS4-47784 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -