TY - GEN A1 - Hertwig, Andreas A1 - Ermilova, Elena T1 - Optical constants of a single AlN layer on Si N2 - Spectroscopic ellipsometry was used to determine the thickness and dielectric function of a Aluminium Nitride (AlN) layer on a Si wafer. The layer was determined to be 170 nm thick. The layer was provided by AIXTRON and manufactured by means of MOVPE. The data was created using a M2000DI spectroscopic ellipsometer from Woollam Co. Inc. Analysis was done using the CompleteEASE software. The model used is a multi-peak oscillator model for the AlN layer. The data resembles common database values for the material AlN. KW - Aluminium nitride KW - Thin solid layers KW - Spectroscopic ellipsometry KW - Compund semiconductors KW - MOVPE PY - 2024 UR - https://zenodo.org/records/12743500 DO - https://doi.org/10.5281/zenodo.12743499 PB - Zenodo CY - Geneva AN - OPUS4-60661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Smales, G. J. T1 - DACHS-MOFs Database for Automation, Characterisation, and Holistic Synthesis N2 - The DACHS (Database for Automation, Characterization and Holistic Synthesis) project aims to create completely traceable experimental data, covering syntheses, measurements, analyses, and interpretations. DACHS MOFs focuses on the synthesis and characterisation of metal-organic frameworks (MOFs), across multiple, automation-assisted experimental series (AutoMOFs), with the overall goal of producing reproducible MOF syntheses. So far > 1200 MOF samples have been synthesised, with SAXS/WAXS data currently being collected on all samples. All results, including those from “failed” syntheses, are included in the database, as results are results and should be considered agnostic to any positive ornegative interpretations. DACHS MOFs represents the initial trial of the DACHS project, serving as a comprehensive resource for researchers aiming to optimize the synthesis and characterization of MOFs. T2 - XIX International Small Angle Scattering Conference CY - Taipei, Taiwan DA - 04.11.2024 KW - Lab automation KW - Synthesis KW - Metal organic frameworks KW - Zif-8 KW - Databases KW - Synthesis data PY - 2024 AN - OPUS4-61626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völker, Christoph A1 - Kruschwitz, Sabine A1 - Moreno Torres, Benjami A1 - Firdous, R. A1 - Zia, G. J. A. A1 - Stephan, D. T1 - Accelerating the search for alkali-activated cements with sequential learning N2 - With 8% of man-made CO2 emissions, cement production is an important driver of the climate crisis. By using alkali-activated binders, part of the energy-intensive clinker production process can be dispensed. However, as numerous raw materials are involved in the manufacturing process here, the complexity of the materials increases by orders of magnitude. Finding a properly balanced binder formulation is like looking for a needle in a haystack. We have shown for the first time that artificial intelligence (AI)-based optimization of alkali-activated binder formulations can significantly accelerate research. The "Sequential Learning App for Materials Discovery" (SLAMD) aims to accelerate practice transfer. With SLAMD, materials scientists have low-threshold access to AI through interactive and intuitive user interfaces. The value added by AI can be determined directly. For example, the CO2 emissions saved per ton of cement can be determined for each development cycle: the more efficient the AI optimization, the greater the savings. Our material database already includes more than 120,000 data points of alternative binders and is constantly being expanded with new parameters. We are currently driving the enrichment of the data with a life cycle analysis of the building materials. Based on a case study we show how intuitive access to AI can drive the adoption of techniques that make a real contribution to the development of resource-efficient and sustainable building materials of the future and make it easy to identify when classical experiments are more efficient. T2 - fib International Congress CY - Oslo, Norway DA - 12.06.2022 KW - Concrete KW - Materials Design KW - Sequential Learning KW - Machine Learning PY - 2022 SP - 1 EP - 9 AN - OPUS4-56634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Duarte Bernardino, Carolina A1 - Lee, Mihyun A1 - Ren, Qun A1 - Ruehle, Bastian T1 - Facile Spray-Coating of Antimicrobial Silica Nanoparticles for High-Touch Surface Protection N2 - The rising threat from infectious pathogens poses an ever-growing challenge. Metal-based nanomaterials have gained a great deal of attention as active components in antimicrobial coatings. Here, we report on the development of readily deployable, sprayable antimicrobial surface coatings for high-touch stainless steel surfaces that are ubiquitous in many healthcare facilities to combat the spread of pathogens. We synthesized mesoporous silica nanoparticles (MSNs) with different surface functional groups, namely, amine (MSN-NH2), carboxy (MSN-COOH), and thiol groups (MSN-SH). These were chosen specifically due to their high affinity to copper and silver ions, which were used as antimicrobial payloads and could be incorporated into the mesoporous structure through favorable host−guest interactions, allowing us to find the most favorable combinations to achieve antimicrobial efficacy against various microbes on dry or semidry high-touch surfaces. The antimicrobial MSNs were firmly immobilized on stainless steel through a simple two-step spray-coating process. First, the stainless steel surfaces are primed with sprayable polyelectrolyte solutions acting as adhesion layers, and then, the loaded nanoparticle dispersions are spray-coated on top. The employed polyelectrolytes were selected and functionalized specifically to adhere well to stainless steel substrates while at the same time being complementary to the MSN surface groups to enhance the adhesion, wettability, homogeneity, and stability of the coatings. The antimicrobial properties of the nanoparticle suspension and the coatings were tested against three commonly found pathogenic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, as well as a fungal pathogen, Candida albicans. Especially MSN-SH loaded with silver ions showed excellent antimicrobial efficacy against all tested pathogens under application-relevant, (semi)dry conditions. The findings obtained here facilitate our understanding of the correlation between the surface properties, payloads, and antimicrobial activity and show a new pathway toward simple and easily deployable solutions to combat the spread of pathogens with the help of sprayable antimicrobial surface coatings. KW - Mesoporous silica nanoparticles KW - Thin films KW - Antimicrobial coatings KW - Spray-coating KW - Infectious diseases KW - Pathogen transmission KW - High-touch surfaces PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626269 DO - https://doi.org/10.1021/acsami.4c18916 SN - 1944-8252 SP - 1 EP - 13 PB - ACS Publications CY - Washington, DC AN - OPUS4-62626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seilert, J. T1 - (Re)engineering functional fat phases – bridging industry and ivory tower N2 - The crystallization kinetics of commercial structuring fats are determined by the interplay of polymorphic transitions and the formation of mixed crystals involving three primary melting groups: H3, H2M, and H2U. Here, H represents long-chain saturated fatty acids, M denotes medium-chain saturated fatty acids, and U signifies unsaturated fatty acids. Assigning the molecular makeup of structuring fats to the kinetic pathways proves to be a challenging task when dealing with complex mixtures. For example, incorporating H2M triglycerides alters the crystallization pathways substantially by impacting the formation of mixed crystals with and between H3 and H2U triglycerides (TAGs). However, determining the impact of specifics in molecular composition, e.g., fatty acid content and TAG asymmetry, remains a complex challenge when dealing with intricate mixtures. This might be overcome by targeting distinct melting groups and comparing their behavior in complex mixtures to academic replicates. This study examined four commercial blends with different fatty acids (palmitic versus stearic acid) and varying H3 contents (8% versus 4%), C8-P, C8-S, C4-P, and C4-S. The H2M content and sum of structuring melting groups was kept constant at 9 % and 25 %, respectively. Further, the commercial blends were replicated using synthetic triglycerides representing the main melting groups: PPP and SSS for H3, PLaP and SLaS for H2M and POP and SOS for H2U – resulting in academic blends A8-P, A8-S, A4-P, and A4-S. The crystallization under quiescent conditions at a cooling rate of 3.5 K/min of all eight blends was studied via DSC and time-resolved SAXS/WAXS. While the P-based commercial blends (C8-P and C4-P) followed typical crystallization routes including an α-β’ transition and clear dependency on H3 content, the S-based counterparts, C8-S and C4-S, showed an α-phase of prolonged stability and evidence of two distinct β’ phases. Differences between commercial and academic blends are discussed. T2 - 2nd Berlin Symposium on Structured Lipid Phases CY - Berlin, Germany DA - 30.09.2024 KW - Lipid phases KW - Thermal structuring KW - Crystallography KW - X-ray scattering PY - 2024 AN - OPUS4-61334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senbill, Haytham A1 - Gangan, Amr A1 - Saeed, Ahmed M. A1 - Gad, Mohammed E. A1 - Zeb, Jehan A1 - Fahmy, Alaa T1 - Effects of copper/graphene oxide core-shell nanoparticles on Rhipicephalus ticks and their detoxification enzymes N2 - Nanopesticides have been recently introduced as novel pesticides to overcome the drawbacks of using traditional synthetic pesticides. The present study evaluated the acaricidal activity of Copper/Graphene oxide core-shell nanoparticles against two tick species, Rhipicephalus rutilus and Rhipicephalus turanicus. The Copper/Graphene oxide core-shell nanoparticles were synthetized through the solution plasma (SP) method under different conditions. The nanoparticles synthesized at 180 W and 45 min were highly toxic to Rh. rutilus and Rh. turanicus, with 50% lethal concentration (LC50) values of 248.1 and 195.7 mg ml−1, respectively, followed by those which were synthesized at 120 W/30 mins (LC50 = 581.5 and 526.5 mg ml−1), 120 W/15 mins (LC50 = 606.9 and 686.7 mg ml−1), and 100/45 mins (LC50 = 792.9 and 710.7 mg ml−1), after 24 h of application. The enzyme assays revealed that 180 W/45 min treatment significantly inhibited the activity of acetylcholinesterase (115 ± 0.81 and 123 ± 0.33 U/ mg protein/min) and superoxide dismutase (290 ± 0.18 and 310 ± 0.92 U/ mg protein/min) in Rh. rutilus and Rh. turanicus, respectively, as compared with the negative control. The results also revealed a significantly increased catalase activity (895 ± 0.37 and 870 ± 0.31 U/ mg protein/min) in Rh. rutilus and Rh. turanicus, respectively. The above results indicated that Copper/Graphene oxide core-shell nanoparticles could be a promising alternatives for the management of ticks. KW - Copper/graphene oxide KW - Nanopesticides KW - Rhipicephalus rutilus KW - Rhipicephalus turanicus KW - Acetylcholinesterase KW - Antioxidants PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629359 DO - https://doi.org/10.1038/s41598-025-86560-4 SN - 2045-2322 VL - 15 SP - 1 EP - 12 PB - Springer Nature CY - London AN - OPUS4-62935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin T1 - Temperature in micromagnetism: Cell size and scaling effects of the stochastic Landau-Lifshitz equation N2 - The movement of the macroscopic magnetic moment in ferromagnetic systems can be described by the Landau-Lifshitz (LL) or Landau-Lifshitz-Gilbert (LLG) equation. These equations are strictly valid only at absolute zero temperature. To include temperature effects a stochastic version of the LL or LLG equation for a spin density of one per unit cell can be used instead. To apply the stochastic LL to micromagnetic simulations, where the spin density per unit cell is generally higher, a conversion regarding simulation cell size and temperature has to be established. Based on energetic considerations, a conversion for ferromagnetic bulk and thin film systems is proposed. The conversion is tested in micromagnetic simulations which are performed with the Object Oriented Micromagnetic Framework (OOMMF). The Curie temperatures of bulk Nickel, Cobalt and Iron systems as well as Nickel thin-film systems with thicknesses between 6.3 mono layer (ML) and 31ML are determined from micromagnetic simulations. The results show a good agreement with experimentally determined Curie temperatures of bulk and thin film systems when temperature scaling is performed according to the presented model. T2 - #RSCposter 2023 CY - Online meeting DA - 28.02.2023 KW - Exchange interaction KW - Ferromagnetism KW - LLG KW - Landau Lifshitz equation KW - Magnetic moment KW - Magnetic nanoparticles KW - Micromagnetism KW - OOMMF KW - Object oriented micromagnetic framework KW - Stochastic Landau Lifshitz Gilbert equation KW - Temperature scaling PY - 2023 AN - OPUS4-57062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tang, Chi-Long T1 - Sub-4 nm particles from FFF-3D printing measured with the TSI 1 nm CPC and the Airmodus A11 nCNC N2 - Concerns have been raised as Fused Filament Fabrication (FFF) desktop 3D printer emits harmful ultrafine particles (dP < 100 nm) during operation in indoor spaces. However, the vast majority of previous emission studies have neglected the possible occurrence of sub-4 nm particles by using conventional condensation particle counter (CPC) for detection. Thus, the total particle emission could be systematically underestimated. This study has compared two diethylene glycol (DEG) based instruments to evaluate their suitability for measuring organic FFF particles in the sub-4 nm size range either as particle counter or as a particle size spectrometer. T2 - European Aerosol Conference 2024 CY - Tampere, Finland DA - 25.08.2024 KW - Air pollution KW - Emission testing KW - FFF-3D printing KW - Sub-4nm particles KW - Ultrafine particles PY - 2024 AN - OPUS4-60930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Madkour, Sherif A. A1 - Gawek, Marcel A1 - Penner, P. A1 - Paneff, F. A1 - Zhang, X. A1 - Gölzhäuser, A. A1 - Schönhals, Andreas T1 - Can Polymers be Irreversibly Adsorbed on Carbon Nanomembranes? A Combined XPS, AFM, and Broadband Dielectric Spectroscopy Study N2 - Carbon nanomembranes are synthetic two-dimensional sheets with nanometer thickness, macroscopic lateral dimensions, and high structural homogeneity. They have great application potential in various branches of nanotechnology. Because of their full carbon structure, it is not clear whether macromolecules like poly(methyl methacrylate) (PMMA) can be irreversibly adsorbed on their surface. Here, irreversible adsorption means that the polymer chains cannot be removed by a leaching process, which is assumed in technological transfer processes. However, if polar defects are present on the carbon nanomembranes (CNMs), it may occur that polymers can be irreversibly adsorbed. To address this question, PMMA was spin-coated on top of CNMs, annealed for a specific time at different temperatures, and then tried to be removed by a acetone treatment in a leaching approach. The samples were investigated in detail by atomic force microscopy, X-ray photoelectron spectroscopy, and broadband dielectric spectroscopy, where the latter method has been applied to CNMs for the first time. Unambiguously, it was shown that PMMA can be adsorbed on the surface of CNMs after annealing the sample above the glasstransition temperature of PMMA. The general occurrence of polar defects on the surface of CNMs and the adsorption of polymers open opportunities for advanced innovative hybrid materials combining the properties of the CNM with those of the polymer. KW - Carbon Nanomembranes KW - Irreversible adsorption KW - Broadband dielectric spectroscopy KW - XPS spctroscopy KW - Atomic force microscopy PY - 2022 DO - https://doi.org/10.1021/acsapm.2c01320 SN - 2637-6105 VL - 4 IS - 11 SP - 8377 EP - 8385 PB - ACS AN - OPUS4-56067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheffler, F. A1 - Tielemann, Christopher T1 - Crystallization of glasses studied with PEEM N2 - A heat treated glass that formed crystals under controlled conditions can be a glass ceramic. A proper understanding of crystallization in glassy melts is needed yet still lacking. Involved processes include the mobility of Elements within the glass during heat treatment and the reorganization of atomic bonds during crystallization. This change in coordination number of certain elements is easily observable in bulk glass samples during heat treatment with XAS. Our plan was to monitor these reorganization processes in situ at the immediate surface during heat treatment with PEEM to get time and spatial resolved data. T2 - Joint Meeting of the Polish Synchrotron Radiation Society and SOLARIS Users CY - Online meeting DA - 09.09.2020 KW - Glass KW - Surface KW - Peem KW - Synchrotron PY - 2020 AN - OPUS4-51336 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -