TY - JOUR A1 - Ricci, M. A1 - Shegunova, P. A1 - Conneely, P. A1 - Becker, Roland A1 - Torres, M. M. A1 - Osuna, M. A. A1 - On, T.P. A1 - Man, L.H. A1 - Baek, S.-Y. A1 - Kim, B. A1 - Hopley, C. A1 - Liscio, C. A1 - Warren, J. A1 - Le Diouron, V. A1 - Lardy-Fontan, S. A1 - Lalere, B. A1 - Mingwu, S. A1 - Kucklick, J. A1 - Vamathevan, V. A1 - Matsuyama, S. A1 - Numata, M. A1 - Brits, M. A1 - Quinn, L. A1 - Fernandes-Whaley, M. A1 - Gören, A.C. A1 - Binici, B. A1 - Konopelko, L. A1 - Krylov, A. A1 - Mikheeva, A. T1 - CCQM-K102: Polybrominated diphenyl ethers in sediment JF - Metrologia N2 - The key comparison CCQM-K102: Polybrominated diphenyl ethers in sediment was coordinated by the JRC, Directorate F - Health, Consumers & Reference Materials, Geel (Belgium) under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM). Thirteen National Metrology institutes or Designated Institutes and the JRC participated. Participants were requested to report the mass fraction (on a dry mass basis) of BDE 47, 99 and 153 in the freshwater sediment study material. The sediment originated from a river in Belgium and contained PBDEs (and other pollutants) at levels commonly found in environmental samples. The comparison was designed to demonstrate participants' capability of analysing non-polar organic molecules in abiotic dried matrices (approximate range of molecular weights: 100 to 800 g/mol, polarity corresponding to pKow < −2, range of mass fraction: 1–1000 μg/kg). All participants (except one using ultrasonic extraction) applied Pressurised Liquid Extraction or Soxhlet, while the instrumental analysis was performed with GC-MS/MS, GC-MS or GC-HRMS. Isotope Dilution Mass Spectrometry approach was used for quantification (except in one case). The assigned Key Comparison Reference Values (KCRVs) were the medians of thirteen results for BDE 47 and eleven results for BDE 99 and 153, respectively. BDE 47 was assigned a KCRV of 15.60 μg/kg with a combined standard uncertainty of 0.41 μg/kg, BDE 99 was assigned a KCRV of 33.69 μg/kg with a combined standard uncertainty of 0.81 μg/kg and BDE 153 was assigned a KCRV of 6.28 μg/kg with a combined standard uncertainty of 0.28 μg/kg. The k-factor for the estimation of the expanded uncertainty of the KCRVs was chosen as k = 2. KW - Intercomparison KW - Traceability KW - Nation metrology institutes PY - 2017 DO - https://doi.org/10.1088/0026-1394/54/1A/08026 SN - 0026-1394 SN - 1681-7575 VL - 54 SP - 08026, 1 EP - 82 AN - OPUS4-41998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Souza Machado, A. A. A1 - Lau, C. W. A1 - Till, J. A1 - Kloas, W. A1 - Lehmann, A. A1 - Becker, Roland A1 - Rillig, M. C. T1 - Impacts of microplastics on the soil biophysical environment JF - Environmental Science and Technology N2 - Soils are essential components of terrestrial ecosystems that experience strong pollution pressure. Microplastic contamination of soils is being increasingly documented, with potential consequences for soil biodiversity and function. Notwithstanding, data on effects of such contaminants on fundamental properties potentially impacting soil biota are lacking. The present study explores the potential of microplastics to disturb vital relationships between soil and water, as well as its consequences for soil structure and microbial function. During a 5-weeks garden experiment we exposed a loamy sand soil to environmentally relevant nominal concentrations (up to 2%) of four common microplastic types (polyacrylic fibers, polyamide beads, polyester fibers, and polyethylene fragments). Then, we measured bulk density, water holding capacity, hydraulic conductivity, soil aggregation, and microbial activity. Microplastics affected the bulk density, water holding capacity, and the functional relationship between the microbial activity and water stable aggregates. The effects are underestimated if idiosyncrasies of particle type and concentrations are neglected, suggesting that purely qualitative environmental microplastic data might be of limited value for the assessment of effects in soil. If extended to other soils and plastic types, the processes unravelled here suggest that microplastics are relevant long-term anthropogenic stressors and drivers of global change in terrestrial ecosystems. KW - Mikroplastik KW - Einfluß KW - Boden PY - 2018 DO - https://doi.org/10.1021/acs.est.8b02212 SN - 0013-936X SN - 1520-5851 VL - 52 IS - 17 SP - 9656 EP - 9665 PB - American Chemical Society AN - OPUS4-46547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Souza Machado, A. A. A1 - Lau, C. W. A1 - Kloas, W. A1 - Bergmann, J. A1 - Bachelier, J. B. A1 - Faltin, E. A1 - Becker, Roland A1 - Görlich, A. S. A1 - Rillig, M. C. T1 - Microplastics can change soil properties and affect plant performance JF - Environmental Science and Technology N2 - Microplastics can affect biophysical properties of the soil. However, little is known about the cascade of events in fundamental levels of terrestrial ecosystems, i.e., starting with the changes in soil abiotic properties and propagating across the various components of soil−plant interactions, including soil microbial communities and plant traits. We investigated here the effects of six different microplastics (polyester fibers, polyamide beads, and four fragment types: polyethylene, polyester terephthalate, polypropylene, and polystyrene) on a broad suite of proxies for soil health and performance of spring onion (Allium fistulosum). Significant changes were observed in plant biomass, tissue elemental composition, root traits, and soil microbial activities. These plant and soil responses to microplastic exposure were used to propose a causal model for the mechanism of the effects. Impacts were dependent on particle type, i.e., microplastics with a shape similar to other natural soil particles elicited smaller differences from control. Changes in soil structure and water dynamics may explain the observed results in which polyester fibers and polyamide beads triggered the most pronounced impacts on plant traits and function. The findings reported here imply that the pervasive microplastic contamination in soil may have consequences for plant performance and thus for agroecosystems and terrestrial biodiversity. KW - Mikroplastik KW - Boden KW - Pflanzenwachstum PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-484181 DO - https://doi.org/10.1021/acs.est.9b01339 SN - 0013-936X SN - 1520-5851 VL - 53 IS - 10 SP - 6044 EP - 6052 PB - ACS AN - OPUS4-48418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Günther A1 - Hof, T. A1 - Jacquiot, C. A1 - Lohwag, K. A1 - Rennerfelt, E. A1 - Wälchli, O. T1 - Vergleichsversuche zur Laboratoriumsprüfung der pilzwidrigen Wirksamkeit von Holzschutzmitteln JF - Holz als Roh- und Werkstoff PY - 1966 SN - 0018-3768 VL - 24 IS - 2 SP - 53 EP - 58 PB - Springer CY - Berlin AN - OPUS4-10498 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gupta, P. A1 - Karnaushenko, D. D. A1 - Becker, C. A1 - Okur, I. E. A1 - Melzer, M. A1 - Özer, B. A1 - Schmidt, O. G. A1 - Karnaushenko, D. T1 - Large Scale Exchange Coupled Metallic Multilayers by Roll-to-Roll (R2R) Process for Advanced Printed Magnetoelectronics JF - Advanced Materials Technologies N2 - Till now application of printed magnetoelectronics is hindered by lack of large area exchange coupled metallic multilayers required to produce printable magneto-sensory inks. Large-scale roll-to-roll (R2R) fabrication process is an attractive approach owing to its capabilities for high volume, high throughput, and large area manufacturing. Precise and high performance R2R sputtering technology is developed to fabricate large area giant magnetoresistive (GMR) thin-films stacks that contain 30 metallic bilayers prepared by continuous R2R sputtering of Co and Cu sequential on a hundred meters long polyethylene terephthalate (PET) web. The R2R sputtered Co/Cu multilayer on a 0.2 × 100 m2 PET web exhibits a GMR ratio of ≈40% achieving the largest area exchange coupled room temperature magneto-sensitive system demonstrated to date. The prepared GMR thin-film is converted to magnetosensitive ink that enables printing of magnetic sensors with high performance in a cost-efficient way, which promotes integration with printed electronics. An average GMR ratio of ≈18% is obtained for 370 printed magnetic sensors. The realized precise R2R sputtering approach can also be extended to a wide range of hybrid thin-film material systems opening up a path for new functional inks applied with printing technologies. KW - Printed Electronics KW - Flexible Magnetic Sensors KW - Roll-to-Roll Processing KW - Functional Materials KW - Upscaling PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552344 DO - https://doi.org/10.1002/admt.202200190 SN - 2365-709X SP - 1 EP - 11 PB - Wiley-VCH CY - Weinheim, Deutschland AN - OPUS4-55234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ahiboz, D. A1 - Andresen, Elina A1 - Manley, P. A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Becker, C. T1 - Metasurface-Enhanced Photon Upconversion upon 1550 nm Excitation JF - Advanced Science News N2 - Photon upconversion upon 1550 nm excitation is of high relevance for applications in the third biological excitation window, for photovoltaics beyond current limitations, and enables appealing options in the field of glass Fiber telecommunications. Trivalent doped erbium ions (Er3+) are the material of choice for 1550 nm excited upconversion, however, they suffer from a low absorption cross-section and a low brightness. Therefore, the ability of Silicon metasurfaces to provide greatly enhanced electrical near-fields is employed to enable efficient photon upconversion even at low external Illumination conditions. Hexagonally shaped β-NaYF4:Er3+ nanoparticles are placed on large-area silicon metasurfaces designed to convert near-infrared (1550 nm) to visible light. More than 2400-fold enhanced photon upconversion luminescence is achieved by using this metasurface instead of a planar substrate. With the aid of optical simulations based on the finite-element method, this result is attributed to the coupling of the excitation source with metasurface resonances at appropriate incident angles. Analysis of the excitation power density dependence of upconversion luminescence and red-to-green-emission ratios enables the estimation of nanoscale near-field enhancement on the metasurface. The findings permit the significant reduction of required external excitation intensities for photon upconversion of 1550 nm light, opening perspectives in biophotonics, telecommunication, and photovoltaics. KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Single particle KW - Brightness KW - NIR KW - Mechanism KW - Single enhancement KW - SWIR KW - Method PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537193 DO - https://doi.org/10.1002/adom.202101285. SN - 2195-1071 VL - 9 IS - 24 SP - 2101285 PB - Wiley-VCH-GmbH AN - OPUS4-53719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahiboz, D. A1 - Andresen, Elina A1 - Manley, P. A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Becker, C. T1 - Enhanced photon upconversion using erbium-doped nanoparticles interacting with silicon metasurfaces T2 - Proceeding 48th Photovoltaic Specialists Conference (PVSC) N2 - Photon upconversion (UC) using trivalent erbium (Er+3) doped crystals is a promising concept to harness near infrared photons of the solar spectrum which cannot be directly absorbed by silicon solar cells. However, their UC efficiency at low-intensity 1 sun illumination is not relevant on device level so far. Exploiting giant near-field enhancement effects on metasurfaces is an appealing approach to enable efficient UC at low irradiance conditions. Here, we report on more than 1000-fold enhanced photon UC of NaYF4:Er+3 nanoparticles interacting with the near-fields supported by a silicon metasurface under 1550 nm excitation. T2 - 48th Photovoltaic Specialists Conference (PVSC) CY - Online meeting DA - 20.06.2021 KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Brightness KW - NIR KW - Mechanism KW - Modeling KW - Simulation KW - Energy transfer KW - Photonic crystal KW - Enhancement strategy PY - 2021 DO - https://doi.org/10.1109/pvsc43889.2021.9518495 SP - 1 EP - 3 PB - IEEE CY - Berlin AN - OPUS4-53786 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulla, Hannes A1 - Becker, C. A1 - Michalchuk, Adam A1 - Linberg, Kevin A1 - Paulus, B. A1 - Emmerling, Franziska T1 - Tuning the Apparent Stability of Polymorphic Cocrystals through Mechanochemistry JF - Crystal Growth & Design N2 - Mechanochemistry has become a valuable method for the synthesis of new materials and molecules, with a particular strength for screening and preparing multicomponent crystals. In this work, two novel cocrystals of pyrazinamide (PZA) with pimelic acid (PA) were prepared mechanochemically. Their formation was monitored in real time by in situ synchrotron powder X-ray diffraction. Control over the polymorphic form was obtained through the selective choice of liquid additive via liquid assisted grinding. Slurry experiments and dispersion-corrected density functional theory calculations suggest that Form I is the thermodynamically stable form under ambient conditions. Upon aging, Form II converts to Form I. The stability of Form II upon aging was found to depend strongly on the milling duration, intensity, and material of the milling vessels. Longer or higher energy milling drastically increased the lifetime of the Form II product. For the first time, this work also demonstrates that the choice of milling jar can have a decisive effect on the aging stability of a bulk polymorphic powder. In contrast to material prepared in steel milling vessels, the preparation of Form II in Perspex (PMMA) vessels increased its lifetime 3-fold. These findings offer a new dimension to garnering control over mechanochemical cocrystallization and demonstrate the critical importance of the careful and timely ex situ screening of ball mill grinding reactions. This will be of importance for potential industrial applications of mechanochemical cocrystallization where understanding polymorph longevity is crucial for the development of a robust preparative protocol. KW - Physical and chemical processes KW - Organic compounds KW - Liquids KW - Materials KW - Stability PY - 2019 DO - https://doi.org/10.1021/acs.cgd.9b01158 VL - 19 IS - 12 SP - 7271 EP - 7279 PB - ACS Publications AN - OPUS4-50281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Essmann, M. A1 - Becker, S. F. A1 - Witt, Julia A1 - Zhan, J. A1 - Chimeh, A. A1 - Korte, A. A1 - Zhong, J. A1 - Vogelgesang, R. A1 - Wittstock, G. A1 - Lienau, C. T1 - Vectorial near-field coupling JF - Nature Nanotechnology N2 - The coherent exchange of optical near fields between two neighbouring dipoles plays an essential role in the optical properties, quantum dynamics and thus the function of many naturally occurring and artificial nanosystems. These interactions are challenging to quantify experimentally. They extend over only a few nanometres and depend sensitively on the detuning, dephasing and relative orientation (that is, the vectorial properties) of the coupled dipoles. Here, we introduce plasmonic nanofocusing spectroscopy to record coherent light scattering spectra with 5 nm spatial resolution from the apex of a conical gold nanotaper. The apex is excited solely by evanescent fields and coupled to plasmon resonances in a single gold nanorod. We resolve resonance energy shifts and line broadenings as a function of dipole distance and relative orientation. We demonstrate how These phenomena arise from mode couplings between different vectorial components of the interacting optical near fields, specifically from the coupling of the nanorod to both transverse and longitudinal polarizabilities of the taper apex. KW - Plasmon resonance KW - Coherent exchange KW - Optical near field KW - Plasmonic nanofocusing spectroscopy PY - 2019 DO - https://doi.org/10.1038/s41565-019-0441-y SN - 1748-3387 VL - 14 IS - 7 SP - 698 EP - 704 PB - Nature AN - OPUS4-48028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Würth, Christian A1 - Manley, P. A1 - Voigt, R. A1 - Ahiboz, D. A1 - Becker, C. A1 - Resch-Genger, Ute T1 - Metasurface Enhanced Sensitized Photon Upconversion: Toward Highly Efficient Low Power Upconversion Applications and Nanoscale E-Field Sensors JF - Nano Letters N2 - Large-scale nanoimprinted metasurfaces based on silicon photonic crystal slabs were produced and coated with a NaYF4:Yb3+/Er3+ upconversion nanoparticle (UCNP) layer. UCNPs on these metasurfaces yield a more than 500-fold enhanced upconversion emission compared to UCNPs on planar surfaces. It is also demonstrated how the optical response of the UCNPs can be used to estimate the local field energy in the coating layer. Optical simulations using the finite element method validate the experimental results and the calculated spatial three-dimensional field Energy distribution helps us to understand the emission enhancement mechanism of the UCNPs closely attached to the metasurface. In addition, we analyzed the spectral shifts of the resonances for uncoated and coated metasurfaces and metasurfaces submerged in water to enable a prediction of the optimum layer thicknesses for different excitation wavelengths, paving the way to applications such as electromagnetic field sensors or bioassays. KW - Nanoparticles KW - Upconversion KW - Metasurface KW - Field sensor KW - Emission enhancement KW - Photonic crystal PY - 2020 DO - https://doi.org/10.1021/acs.nanolett.0c02548 VL - 20 IS - 9 SP - 6682 EP - 6689 PB - ACS Publications AN - OPUS4-51427 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -