TY - CONF A1 - Resch-Genger, Ute T1 - Introduction to Fluorescence Spectroscopy N2 - A brief introduction to fluorescence spectroscopy will be provided, ranging from typically measured fluorescence quantities over instrument-specific contributions to measured fluorescence signals to selected applications. In this context, an overview of the photoluminescence properties of molecular and nanoscale luminescence reporters will be given including a brief insight into their photophysics and fluorescence standards designed by division Biophotonics for the calibration and instrument performance validation of fluorescence measuring devices will be presented. T2 - Analytical Academy CY - Berlin, Germany DA - 13.01.2020 KW - Linearity KW - Fluorescence KW - Dye KW - Quality assurance KW - Nnano particle KW - Method KW - Measurement uncertainty KW - Quantification PY - 2020 AN - OPUS4-51618 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Praktische Erfahrungen zur Granulometrie von Pulvern im Submikron- und Nanobereich N2 - Der Vortrag beleuchtet insbesondere die Herausforderungen die sich bei der Dispergierung der Nanopulver aufgrund der hohen Adhäsivkräfte ergeben. Die Bewertung der Probenpräparation ist nur indirekt zugänglich, aber essentiell für die Zuverlässigkeit der Messergebnisse. Anhand von Beispielen werden Lösungsvorschläge aufgezeigt. Der Vortrag schließt mit einem Vorschlag zur Strategie der Herangehensweise bei der Partikelgrößenbestimmung von Nanopulvern. T2 - Sitzung des Fachausschusses "Material- und Prozessdiagnostik" der Deutschen Keramischen Gesellschaft: Zuverlässige granulometrische Charakterisierung von Mikro- und Nanopulvern – Voraussetzung für optimierte Keramikwerkstoffe in der Energietechnik CY - Online meeting DA - 19.11.2020 KW - Nano-powder KW - particle size determination KW - dispersion KW - sample preparation PY - 2020 AN - OPUS4-51665 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Szymoniak, Paulina T1 - Spatial Inhomogeneity, Interfaces and Complex Vitrification Behavior of Epoxy-based Materials by Broadband Dielectric Spectroscopy and Calorimetry N2 - Although in the last decades epoxy-based nanocomposites have been successfully adopted by the marine, automotive and aerospace industries they are still rarely studied on a fundamental level. This work deals with an in-depth comparative investigation of the structure, molecular mobility and vitrification kinetics of three bisphenol A diglycidyl ether (DGEBA)-based materials with different nanofillers: I) taurine-modified layered double hydroxide (T-LDH), II) boehmite (BNPs) and III) halloysite nanotubes (HNTs). Moreover, the effect of different hardeners (diethylene triamine and methyl tetrahydrophtalic acid anhydride) on the unfilled epoxy matrix is addressed as well. The chosen methodology comprises I) small – and wide – angle X-ray scattering (SAXS/WAXS) II) calorimetry in the forms of a) conventional DSC and b) static fast scanning calorimetry (FSC), III) broadband dielectric spectroscopy (BDS), as well as IV) specific heat spectroscopy in the forms of a) temperature modulated DSC, and b) temperature modulated FSC. The combination of these techniques proved an intrinsic spatial heterogeneity of epoxy-based materials, evidenced by two separate segmental relaxation processes. Although, depending on the hardener the response of the systems to calorimetric and dielectric investigations was different, in a broader sense similar conclusions can be extracted on the structural heterogeneity. As expected from the two distinct α-processes, it was shown that, in parallel to the main glass transition, epoxy-based materials can exhibit an additional low temperature vitrification mechanism, which was not discussed in prior studies for an unfilled network former. Furthermore, the interfacial region (so-called rigid amorphous fraction) was qualitatively and quantitatively addressed, in dependence of the employed nanofiller structure. T2 - Webinar University of Southern Denmark CY - Online meeting DA - 20.01.2021 KW - BDS KW - Nanocomposites KW - Epoxy KW - Rigid amorphous fraction KW - TMDSC KW - Flash DSC PY - 2021 AN - OPUS4-52036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Laser-induced periodic surface structures: When electromagnetics drives hydrodynamics 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 material upon irradiation of solids with intense laser radiation. Nowadays processing rates of up to m^2/min are enabling new industrial applications in medicine, optics, tribology, biology, etc. Depending on the specific type of LIPSS, their structural sizes 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, however, a vivid, controversial, and long-lasting debate has emerged during the last two 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). This presentation reviews the currently existent theories of LIPSS. A focus is laid on the historic development of the fundamental ideas, their corresponding mathematical descriptions and numerical implementations, along with a comparison and critical assessment of the different approaches. T2 - 28th International Conference on Advanced Laser Technologies (ALT'21) CY - Online meeting DA - 06.09.2021 KW - Laser-induced periodic surface structures, LIPSS KW - Electromagnetic scattering KW - Matter reorganization PY - 2021 DO - https://doi.org/10.24412/cl-35039-2021-21-25-25 AN - OPUS4-53218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolmangadi, Mohamed Aejaz T1 - Phase Behaviour and Molecular Mobility of a confined Ionic Liquid Crystal N2 - Liquid crystalline mesophases in nanoconfinement exhibit intriguing orientational order and phase transition behaviors. Here, the plastic crystal to hexagonal columnar, and hexagonal columnar to isotropic transition temperatures are studied for the guanidinium-based ionic discotic liquid crystal confined in self- ordered nanoporous alumina membranes. The phase transition temperature of the plastic crystal to hexagonal columnar phase is reduced with inverse pore diameter. The hexagonal columnar to isotropic transition is suppressed completely in all pores and a possible explanation is given. The results are of technological relevance for the design of liquid crystal-based devices such as batteries and sensors with optimum tunable properties. T2 - Interpore Konferenz CY - Online meeting DA - 31.05.2021 KW - Ionic Liquid crystals KW - Nanoconfinement KW - Conductivity PY - 2021 AN - OPUS4-53298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul T1 - Comparative study of suitable preparation methods to evaluate irregular shaped, polydisperse nanoparticles by scanning electron microscopy (SEM). N2 - Reliable characterization of materials at the nanoscale regarding their physio-chemical properties is a challenging task, which is important when utilizing and designing nanoscale materials. Nanoscale materials pose a potential toxicological hazard to the environment and the human body. For this reason, the European Commission amended the REACH Regulation in 2018 to govern the classification of nanomaterials, relying on number-based distribution of the particle size. Suitable methods exist for the granulometric characterization of monodisperse and ideally shaped nanoparticles. However, the evaluation of commercially available nanoscale powders is problematic. These powders tend to agglomerate, show a wide particle size distribution and are of irregular particle shape. Zinc oxide, aluminum oxide and cerium oxide with particle sizes less than 100 nm were selected for the studies and different preparation methods were used comparatively. First, the nanoparticles were dispersed in different dispersants and prepared on TEM-supported copper grids. Furthermore, individual powders were deposited on carbon-based self-adhesive pads. In addition, the samples were embedded by hot mounting and then ground and polished. The prepared samples were investigated by scanning electron microscopy (including the transmission mode STEM-in-SEM) and Dynamic Light scattering. The software package ImageJ was used to segment the SEM images and obtain the particle sizes and shapes and finally the number-based particles size distribution with size expressed as various descriptors. T2 - Ceramics 2021 CY - Online meeting DA - 19.04.2021 KW - Nanoparticles KW - Preparation KW - Characterization PY - 2021 AN - OPUS4-53272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stawski, Tomasz T1 - Scattering is a powerful tool to follow nucleation and growth of minerals from solutions N2 - In recent years, we have come to appreciate the astounding intricacy of the formation process of minerals from ions in aqueous solutions. The original ‘textbook’ image of these phenomena, stemming from the adaptation of classical nucleation and growth theories, has increased in complexity due to the discovery of a variety of precursor and intermediate species [e.g. 1], including solute clusters (e.g. prenucleation clusters, PNCs), liquid(-like) phases, as well as amorphous and nanocrystalline solids etc. In general, these precursor or intermediate species constitute different, often short-lived, points along the pathway from dissolved ions to the final solids (typically crystals in this context). In this regard synchrotron-based scattering (SAXS/WAXS/HEXD) appears to be the perfect tool to follow in situ and in a time-resolved manner the crystallization pathways because of the temporal and spatial length scales that can be directly accessed with these techniques. Here, we show how we used scattering to probe the crystallization mechanisms of calcium sulfate. CaSO4 minerals (i.e. gypsum, anhydrite and bassanite) are widespread in natural and industrial environments. During the last several years, a number of studies have revealed indeed that nucleation in the CaSO4-H2O system is non-classical. Our SAXS data demonstrate that gypsum precipitation, involves formation and aggregation of sub-3 nm primary species. These species constitute building blocks of an amorphous precursor phase [2]. Further, we show how in situ high-energy X-ray diffraction experiments and molecular dynamics (MD) simulations can be combined to derive the atomic structure of the primary CaSO4 clusters seen at small-angles [3]. We fitted several plausible structures to the derived pair distribution functions and explored their dynamic properties using unbiased MD simulations based on polarizable force fields. Finally, based on combined SAXS/WAXS, broad-q-range measurements, we show that the process of formation of bassanite, a less hydrated form of CaSO4, is very similar to the formation of gypsum: it also involves the aggregation of small primary species into larger disordered aggregates [4]. Based on these recent insights we formulated a tentative general model for calcium sulfate precipitation from solution. This model involves primary species that are formed through the assembly of multiple Ca2+ and SO42- ions into nanoclusters. These nanoclusters assemble into poorly ordered (i.e. amorphous) hydrated aggregates, which in turn undergo ordering into coherent crystalline units of either gypsum or bassanite (and possibly anhydrite). Determination of the structure and (meta)stability of the primary species is important from both a fundamental, e.g. establishing a general non-classical nucleation model, and applied perspective; e.g. allow for an improved design of additives for greater control of the nucleation pathway. T2 - Annual Meeting of German Crystallographic Society (29. Jahrestagung der Deutschen Gesellschaft für Kristallographie - DGK CY - Online meeting DA - 15.03.2021 KW - Scattering KW - Calcium sulfate KW - SAXS/WAXS PY - 2021 AN - OPUS4-53619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolmangadi, Mohamed Aejaz T1 - ILC Meeting N2 - We summarized our recent findings about the molecular dynamics investigation of bulk and finite ionic liquid crystals. We investigate the molecular dynamics and electrical conductivity for a homologous series of linear shaped guanidinium based cyclic ILCs that vary in alkyl chain length, CLCRs (R = 8, 10, 12, 14, 16) by employing broadband dielectric spectroscopy (BDS), and calorimetry comprised of Fast Scanning Calorimetry (FSC) and temperature modulated FSC (TMFSC). Besides conductivity at high temperatures, the dielectric dispersion reveals two relaxation modes: the fast γ and the slow α1 relaxation. The former is assigned to the localized fluctuations while the latter is due to segmental dynamics of the alkyl chains. The γ mode slows down for long chain length CLCs (12,14,16) compared to their shorter analogues. Calorimetric investigation reveals one process, the α2 process, for CLC12,14 and 16 and two processes, α2 and α3, for CLC8 and 10. The α2 process of all CLCRs has a similar temperature dependence as the dielectric α1 relaxation, which indicates both BDS and FSC probe the segmental dynamics of alkyl side chains, as observed for the bent shaped cyclic ILCs. We interpret the α3 process of CLC8 and 10 as the segmental dynamics of the cation core. For all CLCRs, the absolute values of DC conductivity increase by 4 orders of magnitude at the transition from the plastic crystalline to hexagonal columnar phase. This increase is due to the change in the underlying conduction mechanism from delocalized electron hopping in the crystalline phase to one dimensional ion mobility in the columnar phase. The glassy dynamics shifts to higher temperatures with increasing alkyl chain length. Conversely, the DC conductivity drops by 3 orders of magnitude from CLC8 to CLC16. T2 - ILC Project Meeting CY - Berlin, Germany DA - 14.09.2021 KW - Ionic Liquid crystals KW - Nanoconfinement KW - Conductivity PY - 2021 AN - OPUS4-53675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Report ISO/TC202/WG4 X-Ray Spectroscopy, Liaisons with VAMAS and ISO/TC229 Nanotechnologies N2 - The presentation is structured in the following three parts: i) Report of the Working Group 4 X-Ray Spectroscopy including the publication of 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, ii) Liaison activities between ISO/TC202 Microbeam Anaylsis and VAMAS/TWA34 Quantitative Microstructural Analysis, and iii) Liaison activities from ISO/TC202 Microbeam Analysis for ISO/TC229 Nanotechnologies. Most relevant projects are highlighted for information and further discussions. New initiatives and better promotion of strategic projects are addressed. T2 - Annual Meeting of ISO/TC 202 Microbeam Analysis CY - Online meeting DA - 25.10.2021 KW - Microbeam Analysis KW - VAMAS KW - ISO/TC 202 KW - ISO/TC 229 KW - electron microscopy KW - X-Ray Spectroscopy KW - EBSD KW - FIB PY - 2021 AN - OPUS4-53625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - Nanomaterial characterisation - The long way to standardisation N2 - In 1981 the OECD published the Test Guideline on Particle size and size distribution. This TG is still a valid document for the measurement of particles all over the world. When nanomaterials gained importance, ISO set up a technical commitee for Nanotechnologies in 2005 and the OECD followed this step in 2006 with the Working Party on Manufactured Nanomaterials. In the following years ISO and OECD published several documents about nanomaterials and the systematisation developed. In 2017 it was finally clear that nanomaterials need to be adressed in another way than chemicals and in 2020 ECHA revised the REACH-Annexes accordingly and included nanomaterials. Unfortunately there is a little problem with this: Only a few applicable test guidelines exit for the measurement of the nanomaterials. Several test guidelines date from 1981 and do not address nanomaterials. The logical next step for the OECD would be to publish a series of test guidelines which are indeed currently prepared and will be shown in this talk. Finally there is an additional need for the future of NM standardisation: Digitalisation. T2 - Bilateral workshop with Uni Bermingham CY - Online meeting DA - 10.03.2021 KW - Nano KW - Standardisation KW - Test guideline KW - OECD KW - Nanomaterial PY - 2021 AN - OPUS4-53822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - Size matters! - Auf dem Weg zu einer neuen OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien N2 - Vorstellung der Ergebnisse bei der Entwicklung einer neuen OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien. Ergebnisse: Ideal sphärische Partikel sind gut und verlässlich mit vielen Methoden charakterisierbar. Reale (Nicht ideale) Materialien sind gut charakterisierbar, wenn eine gewisse Homogenität und Stabilität vorliegt. Stark inhomogene und stark agglomerierende Partikel liefern deutlich unterschiedliche Ergebnisse für verschiedene Methoden. Partikel mit geringen Größenunterschieden lassen sich mit allen Methoden gut charakterisieren. Partikel mit sehr deutlichen Größenunterschieden führen häufig zu einer Unterbewertung der kleineren Partikel. Vollautomatische Partikeldetektion bei elektronenmikroskopischen Aufnahmen ist z.Zt. noch stark fehleranfällig und kann daher nicht empfohlen werden. Es hat sich gezeigt, dass alle Methoden zur Bestimmung der Partikelgrößenverteilung Vor- und Nachteile haben. Es ist dringend zu empfehlen Größenverteilungen immer mit mindestens zwei unterschiedlichen Methoden zu bestimmen: Bildgebend und mit gute Anzahlstatistik. Verschiedene Durchmesser wurden in der TG-PSD mit einem Indexsystem versehen, welches zukünftig Verwechslungen zwischen unterschiedlichen Durchmessern vermeiden soll. Wird ein bestimmter Durchmesser benötigt (z.B. hydrodynamisch, aerodynamisch), muss die Methode passend gewählt werden. Eine Umrechnung von einem Durchmesser in einen anderen ist in der Regel fehlerbehaftet. Es wurde ein einheitliches Reporting-System in der TG-PSD eingeführt. T2 - Fachseminar des Umweltbundesamtes CY - Online meeting DA - 14.04.2021 KW - Nano KW - OECD KW - Prüfrichtlinie KW - Nanomaterial KW - BMU PY - 2021 AN - OPUS4-53823 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien N2 - Abschlusspräsentation des Projektes "OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien" - Projektteil Nanopartikel. Es hat sich gezeigt, dass alle Methoden zur Bestimmung der Partikelgrößenverteilung Vor- und Nachteile haben. Es wird dringend empfohlen Größenverteilungen immer mit mindestens zwei unterschiedlichen Methoden zu bestimmen: Bildgebend und mit gute Anzahlstatistik. Verschiedene Durchmesser wurden in der TG-PSD mit einem Indexsystem versehen, welches zukünftig Verwechslungen zwischen unterschiedlichen Durchmessern vermeiden soll. Wird ein bestimmter Durchmesser benötigt (z.B. hydrodynamisch, aerodynamisch), muss die Methode passend gewählt werden. Eine Umrechnung von einem Durchmesser in einen anderen ist in der Regel fehlerbehaftet. Es wurde ein einheitliches Reporting-System in der TG-PSD eingeführt. T2 - Fachgespräch zur OECD - TG PSD - BMU BMWi BAM BAuA UBA CY - Online meeting DA - 10.09.2021 KW - Nano KW - OECD KW - Nanopartikel KW - Prürfrichtlinie KW - Nanomaterial PY - 2021 AN - OPUS4-53825 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Florian, Camilo T1 - Femtosecond laser-induced oxidation in the formation of periodic surface structures N2 - Laser-induced oxide graded layers may contribute to the formation of a new type of embedded low-spatial frequency LIPSS with an anomalous orientation parallel to the laser polarization. In this contribution, we explore this effect experimentally with femtosecond laser pulses and numerically by finite-difference time-domain (FDTD) calculations. T2 - 2021 Conference on Lasers and Electro-Optics/Europe – European Quantum Electronics Virtual Conferences CY - Online meeting DA - 21.06.2021 KW - Laser-induced periodic surface structures (LIPSS) KW - Surface oxidation KW - Femtosecond laser ablation KW - Finite-difference time-domain calculations PY - 2021 AN - OPUS4-52859 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waniek, Tassilo A1 - Zarinwall, A. T1 - Mechanical coupling of matrix and nanoparticles depending on particle surface modification N2 - Boehmite nanoparticles has been successfully functionalized with APTES. After APTES functionalization further modification with tailored molecules e.g. via carboxylic acids is possible. The tailored surface functionalization is strongly enhanced by improved coupling protocols. Arbitrary variation of the functionalization degree is possible. Thereby the temperature stable APTES functionalization enables a wide range of functional groups. By TGA-MS analysis strong evidence for the bonding situation of the APTES on the boehmite surface has been found. Additionally first experiments has been performed to predict the polymer-particle compatibility enhancement via reverse wetting angle measurements with AFM. T2 - Workshop Acting Principles of Nano-Scaled Matrix Additives for Composite Structures CY - BAM, Berlin, Germany DA - 11.10.2019 KW - Surface modification KW - Nanocomposites KW - Boehmite KW - Silane KW - Thermogravimetry KW - Mass spectrometry PY - 2019 AN - OPUS4-49435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - New reference material candidates for traceable size measurement of non-spherical nanoparticles N2 - New model nanoparticles with well-controlled shape were synthesized within the EMPIR project nPSize - Improved traceability chain of nanoparticle size measurements. Their systematic characterization takes place by the traceable methods scanning/transmission electron microscopy, atomic force microscopy and small angle X-ray scattering. Following reference nanoparticle candidates are under investigation with respect to their homogeneity and stability: titania nanoplatelets (10-15 nm x 50-100 nm), titania bipyramides (~60 nm x 40 nm), titania acicular particles (100 nm x 15-20 nm; aspect ratio 5.5/6), gold nanorods (~10 nm x 30 nm), and gold nanocubes (~55 nm x 55 nm x 55 nm). T2 - HyMET Workshop on optical surface analysis methods for nanostructured layers CY - Berlin, Germany DA - 10.10.2019 KW - Nanoparticles KW - Reference materials KW - Traceability KW - Particle size distribution PY - 2019 AN - OPUS4-49285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wegner, Karl David T1 - Tuning the photoluminescence of inp quantum dots with gallium N2 - Semiconductor nanocrystals (quantum dots, QDs) are well known for their superior photophysical properties and enabled advancements in several key technologies of the 21st century and numerous technological applications. However, the most studied II-VI semiconductor nanocrystals contain the toxic heavy metal element cadmium, which is limiting their utilization in commercial applications. This has drawn the interest to alternative materials with less toxicity but having similar photophysical features. The newest generation of TV screens based on QDs have shown that there is a promising environmentally friendly alternative with similar optoelectronic properties, namely indium phosphide (InP) QDs. InP QDs possess a bulk band gap of 1.35 eV with an exciton Bohr radius of ca. 10 nm and thus allow to tune their photoluminescence (PL) from the visible to the near-infrared. Tuning the size and shape of InP QDs and thus tailor their optoelectronic properties can be achieved by different strategies, which range from different types and concentrations of precursors, synthesis temperature or post-synthetic manipulations like etching. The incorporation of other elements like Gallium within the InP core synthesis is another possibility. Using a GaP intermediate layer before growing a ZnS shell has been shown to increase the PL quantum yield, which has been attributed to reduced lattice strain and the removal of phosphor vacancies. Different Ga precursors were investigated but a thorough investigation in terms of their reactivity, localization in the QD and influence on the photophysical properties is lacking to date. In this contribution we will present the detailed investigation of the presence of two different Ga precursors within the InP core synthesis. Photophysical characterizations (steady-state and PL life-time measurements), transmission electron microscopy, XRD and EDX gave insights into the reactivity of the Ga precursors, the Ga localization in the InP core and influences on the photophysical properties. The variation of the precursor and surfactant concentration and the utilization of different ligands for the Ga precursor allowed tuning the PL emission towards the blue or the red. Depending on the used precursor type we observed the formation of larger-sized InP/GaP core/shell nanocrystals or the formation of InGaP alloy structures enabling to assess the blue range of emission (475 nm). T2 - Zsigmondy Colloquium CY - Dresden, Germany DA - 10.07.2019 KW - Indium phosphide KW - Quantum dots KW - Gallium doping PY - 2019 AN - OPUS4-49426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Femtosecond laser-induced periodic surface structures: from light localization to applications N2 - This presentation reviews the current state in the field of Laser-induced Periodic Surface Structures (LIPSS). These surface nanostructures are a universal phenomenon and can be generated on almost any material by irradiation with intense linearly polarized laser radiation. LIPSS are formed in a “self-ordered” way and are often accompanying material processing applications. They can be produced following a single-step process and enable surface functionalization through the adaption of optical, mechanical and chemical surface properties. Their structural sizes typically range from several micrometers down to less than 100 nanometers exhibiting a clear correlation with the polarization direction of the laser radiation. Various types of surface structures are classified, relevant control parameters are identified, and their material specific formation mechanisms are analyzed for different types of inorganic solids, i.e., metals, semiconductors, and dielectrics, through time-resolved optical experiments and theoretical simulations. Finally, technological applications featuring surface functionalization in the fields of optics, fluidics, medicine, and tribology are discussed. T2 - International Conference on Advanced Laser Technologies (ALT'19) CY - Prague, Czech Republic DA - 15.09.2019 KW - Laser-induced periodic surface structures, LIPSS KW - Femtosecond laser KW - Surface functionalization KW - Electromagnetic scattering PY - 2019 AN - OPUS4-49098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Bestimmung der Partikelgrößenverteilung mittels Zentrifugen-Sedimentationsverfahren nach ISO 13318-2 (Küvette) N2 - Im Vortrag werden das Messprinzip des Zentrifugen-Sedimentationsverfahrens erläutert und die Anforderungen der zugrundeliegenden Normen diskutiert. Es schließen sich umfangreiche Ausführungen zur praktischen Durchführung der Messung, insbesondere auch zu den vorbereitenden Arbeiten, sowie zur Auswertung der Rohdaten an. Nach einem Vergleich der Ergebnisse mit anderen Messverfahren, wird das Verfahren in einer Zusammenfassung bewertet. T2 - Rheologie und Stabilität von dispersen Systemen CY - Potsdam, Germany DA - 03.06.2019 KW - Nanomaterial KW - Partikelgrößenverteilung KW - Analytische Zentrifuge PY - 2019 AN - OPUS4-48286 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Sample Preparation of Nano-Powders for Particle Size Determination N2 - The use of increasingly finer starting powders up to nanopowders can also be observed in the field of ceramics. Their advantages consist, for example, in their lower activation energy, an increase in strength or unique optical properties. However, handling and characterization of the powders are much more difficult. The main reason for this is the very high adhesive forces between the particles and between particles and other surfaces, too. Therefore, submicron and even more so nanoparticles tend to agglomerate and their separation into primary particles during sample preparation prior to particle sizing is of particular challenge. A representative measurement sample is only obtained when it no longer contains agglomerates. The evaluation of the dispersion process and a decision on whether it was successful thus increases in importance for the reliability of the measurement results of particle sizing. The presentation uses examples to show possible approaches and provides information on possible sources of error. It is shown that successful granulometric characterisation of fine powders requires both an improved dispersion technique and very often an effective combination of two or more measurement methods. T2 - 96. Jahrestagung der Deutschen Keramischen Gesellschaft CY - Online Meeting DA - 19.04.2021 KW - Agglomerates KW - Nano-powder KW - Dispersion process PY - 2021 AN - OPUS4-52503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ciornii, Dmitri T1 - Knowledge, Information and Data Readiness Levels (KaRL) approach for Nanorisk Governance N2 - Nanomaterials may have brought many beneficial innovations with them in our daily lives and and have become indispensable for the society. However, one needs to be concerned of the risks which are still unknown and not sufficietly studied and therefore there is a need for a nanorisk governance. At the core of nanorisk governance is gathering, processing and analysing reliable data which will be used for decision making. The challenge is to assure data reliability and transform it into knowledge. To address this challenge, we used analogy to technology readiness level (TRL) approach (developed by NASA), and elaborated knowledge readiness level (KaRL). KaRL is a nine-scale system to categorize data and knowledge (documents) into levels of readiness for particular purposes and to enhance readiness level by using quality and completeness filters, compliance requirements, nanorisk-related tools, stakeholders’ input. By our approach we addressed key issues in nanotechnology such as societal and ethical concerns, circular economy and sustainability, traceability of data, knowledge and decisions. T2 - EC - HORIZON EUROPE NMBP-13 Joint Conference Risk Governance of nanotechnology CY - Online meeting DA - 12.04.2021 KW - Knowledge Readiness Level KW - Nanorisk KW - Nanomaterials KW - Data PY - 2021 AN - OPUS4-52471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - EMPIR nPSize - Improved Traceability Chain of Nanoparticle Size Measurement; What nPSize can offer to CEN/TC 352? N2 - The main outcomes of the EMPIR project nPSize are presented and the suitability of the new capabilities (e.g. reference materials, measurement procedures, inter-laboratory comparisons) as pertinent contributions to normative projects within CEN/TC 352 Nanotechnologies are discussed. E.g. the first technical report of nPSize on full algorithm sequences for nanoparticle detection and size measurement as developed on both a physical basis (SEM, TSEM, AFM and SAXS) and by machine learning is put at disposal. T2 - 29th Meeting of CEN/TC 352 Nanotechnologies CY - Online meeting DA - 25.03.2021 KW - Nanoparticles KW - Electron microscopy KW - CEN/TC 352 Nanotechnologies KW - Particle size distribution KW - Modelling KW - Machine learning PY - 2021 AN - OPUS4-52464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Advanced characterization of nanomaterials N2 - The rational synthesis and use of nanomaterials require the characterization of many different properties, ranging from particle size and size distribution over surface chemistry to more applicationrelevant features like optical, electrochemical, and magnetic properties. In the following, several methods for the characterization of functional groups on nanomaterials, like polymer and silica nanoparticles, semiconductor quantum dots, and lanthanide-based upconversion nanocrystals are presented. Additionally, procedures for the measurement of the key spectroscopic performance parameters of nanomaterials with linear and nonlinear photoluminescence, such as the photoluminescence quantum yield, are presented for the UV/vis/NIR/SWIR. T2 - Summerschool CY - Bad Honnef, Germany DA - 22.07.2019 KW - Quantum yield KW - Nanoparticle KW - Fluorescence KW - Quantum dot KW - NIR KW - SWIR KW - Quality assurance KW - Calibration PY - 2019 AN - OPUS4-48630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René T1 - Spectroscopic ellipsometric analysis of elemental composition and porosity of mesoporous iridium-titanium mixed oxide thin films for electrocatalytic splitting of water N2 - Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of porous films is affected by properties like porosity, film thickness, chemical composition of the material as well as the crystallinity of the framework. The complex morphology of such porous films constitutes a challenge for modern analytical techniques and requires approaches employing the combination/complementation of data of different analytical methods. In this contribution we characterize thin mesoporous iridium-titanium mixed oxide film properties by spectroscopic ellipsometry (SE). Mesoporous iridium oxide - titanium oxide (IrOx-TiOx) films were prepared via dip-coating of a solution containing a triblock-copolymer as structure-directing agent, an iridium precursor as well as a titanium precursor in ethanol. Deposited films with different amounts of iridium (0 wt%Ir to 100 wt%Ir) were synthesized and calcined in air. The thin films were analyzed with SE using the Bruggeman effective medium approximation (BEMA) for modelling. The results were compared with electron probe microanalysis (EPMA) as part of a combined SEM/EDS/STRATAGem Analysis. T2 - 8th International conference on spectroscopic ellipsometry (ICSE-8) CY - Barcelona, Spain DA - 26.05.2019 KW - Mesoporous iridium-titanium mixed oxides KW - Thin films KW - Spectroscopic ellipsometry KW - Oxygen evolution reaction KW - EPMA KW - Ellipsometric porosimetry PY - 2019 AN - OPUS4-48387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - High-Quality Experimental Data in Electron Microscopy and Microanalysis – What can, and should we jointly do? N2 - There are different ways how to prove the quality of the results obtained by electron microscopy and related microanalysis techniques, e.g. use of validated standard operation procedures, participation in proficiency testing exercises, use of certified reference materials, etc. International standards are able to provide requirements, specifications, guidelines or characteristics of methods, instruments or samples with the final goal that these can be used consistently in accredited laboratories. In the field of electron microscopy and microbeam analysis standardization and metrology are terms which are encountered rather seldom at major conferences and scientific publications. Nevertheless, spectra formats like EMSA/MSA for spectral-data exchange or tagged image file format (TIFF) for SEM, guidelines for performing quality assurance procedures or for the specification of X-ray spectrometers as well as of certified reference materials (CRMs) in EPMA, or measurement of average grain size by electron backscatter diffraction (EBSD), or guidelines for calibrating image magnification in SEM or TEM are ISO standards already published and used successfully by a large part of the electron microscopy and microbeam analysis community. A main and continuous task of ISO/TC 202 and its subcommittees is to identify and evaluate feasible projects/proposals needed to be developed into new international standards, particularly in respect to recent but established technology, such the silicon drift detector (SDD) EDS one. Another international platform in the frame of which pre-standardization work can be organized is VAMAS (Versailles Project on Advanced Materials and Standards). International collaborative projects involving aim at providing the technical basis for harmonized measurements, testing, specifications, and standards to be further developed at ISO level. One key point of VAMAS activities is constituted by inter-laboratory comparisons for high-quality data. In the field of microbeam analysis, the technical working area (TWA) 37 Quantitative Microstructural Analysis deals with corresponding projects. Good ideas, e.g. on analysis of low-Z materials/elements and at low energies are particularly encouraged by directly contacting the author. Support and already available guidance will be supplied. T2 - Microscopy & Microanalysis 2019 CY - Portland, OR, USA DA - 03.08.2019 KW - Pre-standardisation KW - Inter-laboratory comparison KW - VAMAS KW - ISO KW - Electron microscopy KW - Microanalysis PY - 2019 AN - OPUS4-48672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - A look inside nanoparticles N2 - Small-angle scattering is the method of choice when it comes to obtaining information about the interior of nanoparticles. The aim is to make nanotechnology safer. While the use of small-angle neutron scattering (SANS) is limited to a few instruments in the world, small-angle X-ray scattering (SAXS) is widely accessible, with an upward trend. The example of core-shell particles shows how simple their analysis is with data from an Anton Paar laboratory system. Here, SAXS is a central tool for the development of new reference materials based on poly(methyl) acrylate-PVDF core-shell particles. The dimensions of the cores and shells can be precisely determined. A detailed analysis makes it possible to show that the cores contain fluorinated and nonfluorinated polymers, whereas the shell consist only of PVDF. This core-shell particles with a diameter around 40 nm show a significantly higher PVDF beta phase content than the PVDF homopolymer when using an emulsion polymerization technique. This finding is of importance with respect to applications in electroactive devices. T2 - SAXS excites: International SAXS Symposium 2019 CY - Graz, Austria DA - 24.09.2019 KW - Small-angle X-ray scattering KW - SAXS KW - Nanoplastics PY - 2019 AN - OPUS4-49126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fiedler, Saskia T1 - Giant photon bunching of WS2 monolayer in cathodoluminescence N2 - Cathodoluminescence (CL) spectroscopy has become a powerful tool to study nanostructures due to its high spectral and spatial resolution down to sub-nanometer. More recently, CL technique has also been used for second order auto-correlation measurements (g(2)(t)) to identify different single photon emitters and photon bunching in different materials [1-2]. In this work, tungsten disulfide (WS2) monolayers encapsulated in hexagonal boron nitride (hBN) with and without monocrystalline Au nanodisks (NDs) have been studied, using CL and PL spectroscopy as well as g(2)-CL- and PL-measurements. CL and PL maps of different WS2 monolayers before/after Au ND deposition show a narrow peak at ~625 nm without any background emission. In CL, the hBN not only protects WS2 from the electron beam but also acts as a charge carrier sink which substantially increases the CL signal [3]. A further CL enhancement is achieved by Au ND deposition, exhibiting the maximum at the center of the NDs without any size dependence. The PL intensity is unaffected. This indicates that Purcell enhancement cannot be the underlying mechanism. Furthermore, a giant CL-photon bunching of the hBN-encapsulated WS2 monolayers is found which is independent of the applied voltage but highly dependent on the electron beam current. At the lowest current of ~2 pA, a CL bunching factor of up to 160 is observed. Varying thicknesses of the surrounding hBN increases the overall CL signal but does not affect the bunching factor, though it exhibits small local changes within the same flake. In contrast, there is no PL correlation (g(2)(0) = 1). Interestingly, this photon bunching can be further increased by Au NDs, resulting in the highest ever observed bunching factor of close to 2200. Once again, this enhancement is independent of the Au ND’s diameter although some disks show higher bunching factors than others. Most likely, the Au acts as shield for the incoming primary electrons, resulting in an even further decreased current, and thereby, increased bunching. In conclusion, large CL-photon bunching is found in hBN-encapsulated WS2 monolayers which can be substantially enhanced by Au NDs. References [1] M.A. Feldmann, E.F. Demitrescu, D. Bridges, M.F. Chisholm, R.B. Davidson, P.G. Evans, J.A. Hachtel, A. Hu, R.C. Pooser, R.F. Haglund, B.J. Lawrie, Phys. Rev. B, 97, 081404(R) (2018) [2] S. Meuret, L.H.G. Tizei, T. Cazimajou, R. Bourrellier, H.C. Chang, F. Treussartm M. Kociak, Phys. Rev. Letter, 114, 197401 (2015) [3] S. Zheng, J.-K. So, F. Liu, Z. Liu, N. Zheludev, H.J. Fan, Nano Lett., 17, 6475-6480 (2017) T2 - GSELOP2021 CY - Paris, France DA - 23.08.2021 KW - Cathodoluminescence KW - Photon bunching KW - 2D materials KW - TMDCs KW - Au nanodisks KW - Transition metal dichalcogenide KW - Au nanoparticles PY - 2021 AN - OPUS4-53153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Florian, Camilo T1 - Silicon surface amorphization and re-crystallization via single femtosecond laser pulses N2 - Silicon is the material responsible for most of the technological developments during the past century, making it one of the most studied materials along different disciplines. However, there are still unturned stones regarding its superficial re-solidification after femtosecond laser-induced local melting. In this presentation, we report irradiation experiments with single femtosecond pulses (790 nm, 30 fs) with a spatially Gaussian distribution on two different types of silicon with orientations <111> and <100>. The surface modifications were studied in detail via different techniques, including optical microscopy, atomic force microscopy, spectroscopic imaging ellipsometry, energy dispersive X-ray spectroscopy and high-resolution transmission electron microscopy. We quantitatively estimate the resulting radial amorphous layer depth profiles with maximum thicknesses around some tenths of nanometers for fluences in between the melting and ablation thresholds. In particular, spectroscopic imaging ellipsometry (SIE) allowed fast data acquisition using multiple wavelengths to provide experimental measurements for calculating the nanometric radial amorphous layer thickness profiles with micrometric lateral resolution based on a thin-film layer model. SIE proved to be capable of detecting and measuring nanometric structural and chemical modifications (oxidation) on the studied laser spots. The accuracy of the SIE-based calculations is verified experimentally by characterizing an in-depth material lamella via high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (STEM-EDX). For completeness, we present a mathematical modelling for the melt layer thickness considering different optical absorption processes including one photon absorption, two photon absorption and free-carrier absorption, highlighting the relevance of the latter one in the femtosecond laser-induced melting of silicon. T2 - 28th International Conference on Advanced Laser Technologies (ALT'21) CY - Online meeting DA - 06.09.2021 KW - Silicon KW - Femtosecond laser KW - Phase transitions KW - Spectroscopic imaging ellipsometry KW - Transmission electron microscopy PY - 2021 AN - OPUS4-53235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - VAMAS TWA 37 - Quantitative Microstructural Analysis & Liaison with ISO/TC 202 Microbeam Analysis, Liaison with ISO N2 - The progress in activities on Microbeam Analysis under VAMAS/TWA 37 is reviewed. Particularly the liaison with the new projects within the ISO technical committee TC 202 is presented and discussed with respect to the possibility of identifying and launching related VAMAS projects. Need of more promotion for the engagement of more participants from industry and academia at national, European and international level is highlighted. Also, the competition with the other technical working areas (on 'nano' or materials-related) is critically discussed. Further, a short overview of the VAMAS areas of activities is given where Germany is involved. T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 46th Steering Committee Meeting CY - Online meeting DA - 08.09.2021 KW - VAMAS KW - Nanoparticles KW - Standardisation KW - Inter-laboratory comparison KW - ISO/TC 202 KW - ISO/TC 229 KW - ISO/TC 201 KW - Microstructure KW - EBSD PY - 2021 UR - http://www.vamas.org/twa/ AN - OPUS4-53237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Omar, Hassan A1 - Hiid, Gundula A1 - Szymoniak, Paulina A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth kinetics of the adsorbed layer of poly(bisphenol A carbonate) and its effect on the glass transition behavior in thin films N2 - The glass transition behavior of thin films of poly(bisphenol A carbonate) (PBAC) was studied employing ellipsometry. The glass transition temperature increases with the reduction of the film thickness. This result is attributed to the formation of an adsorbed layer with a reduced mobility compared to bulk PBAC. Therefore, for the first time, the growth kinetics of the adsorbed layer of PBAC was investigated, prepared by leaching samples from a 200 nm thin film which were annealed for several times at three different temperatures. The thickness of each prepared adsorbed layer was measured by multiple scans using atomic force microscopy (AFM). Additionally, an unannealed sample was measured. Comparison of the measurements of the unannealed and the annealed samples provides proof of a pre-growth regime for all annealing temperatures which was not observed for other polymers. For the lowest annealing temperature after the pre-growth stage only a growth regime with a linear time dependence is observed. For higher annealing temperatures the growth kinetics changes from a linear to a logarithmic growth regime at a critical time. At the longest annealing times the films showed signs of dewetting where segments of the adsorbed film were removed from the substrate (dewetting by desorption). The dependence of the surface roughness of the PBAC surface on annealing time also confirmed that the films annealed at highest temperatures for the longest times desorbed from the substrate. KW - Ultra thin polymer films PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-574531 DO - https://doi.org/10.1039/D3RA02020G SN - 2046-2069 VL - 13 IS - 21 SP - 14473 EP - 14483 PB - RSC Publishing CY - London AN - OPUS4-57453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fritzsche, Sven A1 - Pauw, Brian Richard A1 - Weimann, Christiane A1 - Sturm, Heinz T1 - First of its kind: A test artifact for direct laser writing N2 - With femtosecond-laser direct writing (fs-LDW) maturing in all aspects as a manufacturing technology, a toolset for quality assurance must be developed. In this work we introduce a first of its kind test artifact. Test artifacts are standardized 3D models with specific geometric features to evaluate the performance of writing parameters. Test artifacts are already common in other 3D additive manufacturing technologies e.g. selective laser melting. The test artifact introduced in this work was developed in particular to accommodate the high geometrical resolution of fs-LDW structures and the limited possibilities to examine the resulting structure. Geometric accuracy, surface adhesion as well as confocal Raman spectroscopy results were considered when evaluating the design of the test artifact. We will explain the individual features and design considerations of our fs-LDW test artifact. The difference between two slicers, Cura and 3DPoli, and the implications on measured feature sizes and the general shape is quantified. The measured geometries are used to derive a general design guide for a specific combination of photoresists, laser power and scanning speed and to analyze the geometric accuracy of a structure produced using these guidelines. The shown test artifact is publicly available as STL file on GitHub (https://github.com/BAMresearch/2PP-TestArtifact) and in the supplement. KW - Laser direct writing KW - Multi photon lithography KW - Reference material KW - Raman spectroscopy KW - Confocal raman imaging KW - Slicers KW - Open data on zenodo PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580951 DO - https://doi.org/10.1088/1361-6501/acc47a VL - 34 IS - 7 SP - 1 EP - 14 PB - IOP Science AN - OPUS4-58095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tarantini, A. A1 - Wegner, Karl David A1 - Dussert, F. A1 - Sarret, G. A1 - Beal, D. A1 - Mattera, L. A1 - Lincheneau, C. A1 - Proux, O. A1 - Truffier-Boutry, D. A1 - Moriscot, C. A1 - Gallet, B. A1 - Jouneau, P.-H. A1 - Reiss, P. A1 - Carriere, M. T1 - Physicochemical alterations and toxicity of InP alloyed quantum dots aged in environmental conditions: A safer by design evaluation N2 - Due to their unique optical properties, quantum dots (QDs) are used in a number of optoelectronic devices and are forecasted to be used in the near future for biomedical applications. The most popular QD composition consists of cadmium selenide (CdSe) or cadmium telluride (CdTe), which has been shown to pose health risks due to the release of toxic cadmium (Cd) ions. Due to similar optical properties but lower intrinsic toxicity, indium phosphide (InP) QDs have been proposed as a safer alternative. Nevertheless, investigations regarding their safety and possible toxicological effects are still in their infancy. The fate and toxicity of seven different water-dispersible indium (In) based QDs, either pristine or after ageing in a climatic chamber, was evaluated. The core of these QDs was composed of indium, zinc and phosphorus (InZnP) or indium, zinc, phosphorus and sulfur (InZnPS). They were assessed either as core-only or as core-shell QDs, for which the core was capped with a shell of zinc, selenium and sulfur (Zn(Se,S)). Their Surface was functionalized using either penicillamine or glutathione. In their pristine form, these QDs showed essentially no cytotoxicity. The particular case of InZnPS QD showed that core-shell QDs were less cytotoxic than core-only QDs. Moreover, surface functionalization with either penicillamine or glutathione did not appreciably influence cytotoxicity but affected QD stability. These QDs did not lead to over-accumulation of reactive oxygen species in exposed cells, or to any oxidative damage to cellular DNA. However, accelerated weathering in a climatic chamber led to QD precipitation and degradation, together with significant cytotoxic effects. Ageing led to dissociation of IneP and ZneS bonds, and to complexation of In Zn ions with carboxylate and/or phosphate moieties. These results show that InZnP and InZnPS alloyed QDs are safer alternatives to CdSe QDs. They underline the necessity to preserve as much as possible the structural integrity of QDs, for instance by developing more robust shells, in order to ensure their safety for future applications. KW - Indium phosphide KW - Safe by design KW - Toxicity KW - EXAFS PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-483070 DO - https://doi.org/10.1016/j.impact.2019.100168 VL - 14 SP - 100168-1 EP - 100168-13 PB - Elsevier AN - OPUS4-48307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fiedler, Saskia A1 - Ton-That, C. A1 - Phillips, M. R. T1 - Defect-free ZnO nanorods with high angular distribution for enhanced excitonic emission N2 - AbstractLow-temperature hydrothermal growth has emerged as a popular method for the fabrication of ZnO nanorods (NRs), increasing the functionality and utility of ZnO-based devices. In this work, we study the influence of growth time, temperature and seed layer on the dimensions and angular distribution of ZnO NRs. High-quality NRs with a crisscrossed 60° angular distribution have been grown with a 20–60 nm diameter and 600 nm length. We show that, within the ideal range of growth parameters, the growth time and temperature have no controllable influence on NR diameter and length, while the deposition method and size of the pre-growth deposited ZnO seeds affects diameter and NR angular alignment. We demonstrate advantages of using crisscross-aligned NRs over planar ZnO for the enhancement of ZnO excitonic emission by optical coupling with gold nanoparticles. These results can be readily adapted for applications that involve surface coating-mediated enhancement of both light emission and injection. KW - ZnO nanorod KW - Hydrothermal growth KW - Seed layer KW - Angular distribution KW - Cathodoluminescence KW - Luminescence enhancement PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618176 DO - https://doi.org/10.1557/s43578-023-00941-x SN - 0884-2914 SN - 2044-5326 VL - 38 IS - 8 SP - 2145 EP - 2155 PB - Springer CY - Berlin AN - OPUS4-61817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schardt, Annika A1 - Schmitt, Johannes A1 - Engelhard, Carsten T1 - Single particle inductively coupled plasma mass spectrometry with nanosecond time resolution N2 - In this proof-of-principle study, we present our contribution to single particle inductively coupled plasma mass spectrometry (spICP-MS) developments with a novel in-house built data acquisition system with nanosecond time resolution (nanoDAQ) and a matching data processing approach. The new system can continuously sample the secondary electron multiplier (SEM) detector signal and enables the detection of gold nanoparticles (AuNP) as small as 7.5 nm with the commercial single quadrupole ICP-MS instrument used in this study. Recording of the SEM signal by the nanoDAQ is performed with a dwell time of approximately 4 ns. A tailored method was developed to process this type of transient data, which is based on determining the temporal distance between detector events that is denoted as event gap (EG). We found that the inverse logarithm of EG is proportional to the particle size and that the number of detector events corresponding to a particle signal distribution can be used to calibrate and determine the particle number concentration (PNC) of a nanoparticle dispersion. Due to the high data acquisition frequency, a statistically significant number of data points can be obtained in 60 s or less and the main time limitation for analyses is merely the sample uptake time and rinsing step between analyte solutions. At this stage, the data processing method provides average information on complete data sets only and will be adapted to enable particle-by-particle analysis with future hardware/software revision. KW - ICP-MS KW - Nanoparticles KW - Nanosecond time resolution KW - Single particle detection PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612706 DO - https://doi.org/10.1039/d3ja00373f SN - 1364-5544 SN - 0267-9477 VL - 39 IS - 2 SP - 389 EP - 400 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-61270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mezera, Marek A1 - Alamri, S. A1 - Hendriks, W. A. P. M. A1 - Hertwig, Andreas A1 - Elert, Anna Maria A1 - Bonse, Jörn A1 - Kunze, T. A1 - Lasagni, A. F. A1 - Römer, G. R. B. E. T1 - Hierarchical micro-/nano-structures on polycarbonate via UV pulsed laser processing N2 - Hierarchical micro/-nanostructures were produced on polycarbonate polymer surfaces by employing a two-step UV-laser processing strategy based on the combination of Direct Laser Interference Patterning (DLIP) of gratings and pillars on the microscale (3 ns, 266 nm, 2 kHz) and subsequently superimposing Laser-induced Periodic Surface Structures (LIPSS; 7–10 ps, 350 nm, 100 kHz) which adds nanoscale surface features. Particular emphasis was laid on the influence of the direction of the laser beam polarization on the morphology of resulting hierarchical surfaces. Scanning electron and atomic force microscopy methods were used for the characterization of the hybrid surface structures. Finite-difference time-domain (FDTD) calculations of the laser intensity distribution on the DLIP structures allowed to address the specific polarization dependence of the LIPSS formation observed in the second processing step. Complementary chemical analyzes by micro-Raman spectroscopy and attenuated total reflection Fourier-transform infrared spectroscopy provided in-depth information on the chemical and structural material modifications and material degradation imposed by the laser processing. It was found that when the linear laser polarization was set perpendicular to the DLIP ridges, LIPSS could be formed on top of various DLIP structures. FDTD calculations showed enhanced optical intensity at the topographic maxima, which can explain the dependency of the morphology of LIPSS on the polarization with respect to the orientation of the DLIP structures. It was also found that the degradation of the polymer was enhanced for increasing accumulated fluence levels. KW - Direct laser interference patterning KW - Laser-induced periodic surface structures (LIPSS) KW - Polycarbonate KW - Hierarchical structures KW - Surface functionalization PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509101 DO - https://doi.org/10.3390/nano10061184 SN - 2079-4991 VL - 10(6) IS - Special issue "Laser-generated periodic nanostructures" SP - 1184-1 EP - 1184-19 PB - MDPI CY - Basel AN - OPUS4-50910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fosodeder, P. A1 - Baumgartner, W. A1 - Steinwender, C. A1 - Hassel, A. W. A1 - Florian, Camilo A1 - Bonse, Jörn A1 - Heitz, J. T1 - Repellent rings at titanium cylinders against overgrowth by fibroblasts N2 - The invention of new miniaturized and smart medical implants continues in all medical fields, including miniaturized heart pacemakers. These implants often come with a titanium (Ti) casing, which may have to be removed after several months or years and shall therefore not be completely overgrown by cells or scar tissue after implantation. Scar tissue is mainly formed by fibroblast cells and extracellular matrix proteins like collagen produced by them. Suppression of fibroblast growth at Ti surfaces could be achieved by 800 nm femtosecond laser-ablation creating self-organized sharp spikes with dimensions in the 10 μm-range which are superposed by fine sub-μm parallel ripples. On flat Ti control samples, the best results regarding suppression of cell growth were obtained on spike-structures which were additionally electrochemically anodized under acidic conditions. When Ti cylinders with a diameter of 8 mm (similar as the pacemakers) were placed upright in a culture of murine fibroblasts, a multi-layer cell growth up to a height of at least 1.5 mm occurred within 19–22 days. We have demonstrated that a laser-structured and anodized ring around the Ti cylinder surface is an effective way to create a barrier that murine fibroblasts were not able to overgrow within this time. KW - Cell-repellent surfaces KW - Femtosecond laser-processing KW - Electrochemical treatment KW - Laser-induced micro- and nanostructures KW - Medical implants PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509966 DO - https://doi.org/10.1515/aot-2019-0070 SN - 2193-8576 SN - 2193-8584 VL - 9 IS - 3 (Topical issue: Laser micro- and nano-material processing - Part 2) SP - 113 EP - 120 PB - De Gruyter CY - Berlin AN - OPUS4-50996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn 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 - Hertwig, Andreas 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 - GEN A1 - Schardt, Annika A1 - Schmitt, Johannes A1 - Engelhard, Carsten T1 - Cover image for the article "Single particle inductively coupled plasma mass spectrometry with nanosecond time resolution" N2 - Image for the front cover of the issue 39(2) of the JAAS (Journal of Analytical Atomic Spectrometry). See Annika Schardt et al., pp. 389–400. Image reproduced by permission of Annika Schardt, Johannes Schmitt and Carsten Engelhard. KW - Analytical chemistry KW - Nanoparticles KW - Single-particle characterization KW - Instrumentation KW - spICP-MS PY - 2024 DO - https://doi.org/10.1039/D4JA90005G SN - 1364-5544 SN - 0267-9477 VL - 39 IS - 2 SP - 295 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-62156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andreato, E. A1 - Panov, N. A1 - Artiga, A. A1 - Osipova, Viktoriia A1 - Resch-Genger, Ute A1 - Ximendes, E. A1 - Molina, P. A1 - Canton, P. A1 - Marin, R. T1 - Indium-Based Fluoride Nanoparticles Doped with Chromium for Near-Infrared Luminescence N2 - Transition metal (TM) and rare earth (RE) ion-doped nanoparticles (NPs) are photoluminescent materials of technological relevance in bioimaging, sensing, and light conversion. Fluoride NPs are particularly attractive in this context, since they combine low-energy phonons, high chemical stability, optical transparency, size, and architecture tunability. Yet, nearly all reported colloidal fluoride NPs (e.g., NaYF4 and LiYF4) can only be efficiently doped with RE3+ and not with luminescent TM ions. Herein, we contribute to filling this gap in materials science by reporting Na3InF6 NPs doped with Cr3+ as a model luminescent TM ion. We unveil the heat-driven NP formation mechanism, which involves a cubic-to-monoclinic phase conversion, similarly to the cubic-tohexagonal phase conversion in NaYF4. Reaction temperatures above 225 °C and reaction time have a limited impact on the NP morphology, while the amount of fluoride precursor and oleylamine grants control over the NP size. After verifying that Na3InF6 NPs show negligible cytotoxicity toward U-87 cell line, we study the optical properties of these NPs upon Cr3+ doping. Temperature-dependent photoluminescence measurements indicate that Cr3+ ions experience a weak crystal field in the Na3InF6 host lattice, while their photoluminescence lifetime varies linearly in the 20−50 °C range. These results set the ground for further studies of photoluminescent TM-doped fluoride NPs, toward their applications in bioimaging, sensing, and light-converting devices. KW - Quality assurance KW - Fluorescence KW - Traceability KW - Nano KW - Particle KW - Synthesis KW - Quantum yield KW - NIR KW - Mechanism KW - Characterization KW - XRD KW - Phase transition KW - Ligand KW - Surface KW - Doping KW - Lifetime PY - 2025 DO - https://doi.org/10.1021/acs.chemmater.4c03335 SN - 1520-5002 SP - 1 EP - 14 PB - American Chemical Society AN - OPUS4-63073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuhlbusch, T. T1 - Size matters! - Auf dem Weg zu einer neuen OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien _ Projektteil BAuA N2 - Vorstellung der Ergebnisse bei der Entwicklung einer neuen OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien. (Projektteil Fasern.) Ergebnisse: Abweichungen zwischen SEM and TEM insbesondere bei langen Fasern Die Anwendung von TEM auf kurze Fasern < 5 µm beschränkt Für SEM wurde keine signifikante Abhängigkeit der Bestimmung der Faserdurchmesser von der Pixelgröße der Aufnahmen festgestellt Für TEM wurde eine Abhängigkeit der Bestimmung der Faserdurchmesser von der Pixelgröße festgestellt Der Einfluss der Bildauswertenden auf die Varianz der Ergebnisse ist klein im Vergleich zu der gesamten Varianz. Nanofasern können mit TEM und SEM bestimmt werden! T2 - Fachseminar des Umweltbundesamtes CY - Online meeting DA - 14.04.2021 KW - Nano KW - Nanofasern KW - OECD KW - Prüfrichtlinie KW - Nanomaterial PY - 2021 AN - OPUS4-53824 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - EMPIR nPSize - Improved Traceability Chain of Nanoparticle Size Measurement N2 - In order to assess new nanomaterials and nanoparticles for potential risks to health and the environment, they need to be well-characterised. The measurement of constituent nanoparticle size, shape, and size distribution are important factors for the risk evaluation process. EMPIR project Improved traceability chain of nanoparticle size measurements (17NRM04, nPSize) is working to assess a range of traceable nanoparticle measurement approaches, including Electron Microscopy (SEM, TEM, STEM-in-SEM), Atomic Force Microscopy and Small Angle X-ray Scattering, and deliver improved calibration methods to users. For the techniques under investigation, physical models of their response to a range of nanoparticle types are developed. Validated reference materials are also used for inter-comparisons of measurement systems, with an evaluation of the associated measurement uncertainty. With project contributions to standards development work, manufacturers will be better placed to assess the human and environmental risks posed by nanomaterials across a whole range of products. T2 - EMPIR nPSize Training Course "Traceable Characterization of Nanoparticles by SAXS" CY - Online meeting DA - 01.02.2021 KW - Nanoparticles KW - Particle size distribution KW - Traceability KW - nPSize KW - SAXS PY - 2021 AN - OPUS4-53883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuhlbusch, T. T1 - OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien - Projektteil Fasern N2 - Abschlusspräsentation des Projektes "OECD Prüfrichtlinie zur Bestimmung der Partikelgröße und Anzahlgrößenverteilung von Nanomaterialien". (Projektteil Fasern) T2 - Fachgespräch zur OECD - TG PSD - BMU BMWi BAM BAuA UBA CY - Online meeting DA - 10.09.2021 KW - Nano KW - Nanofasern KW - OECD KW - Prüfrichtlinie KW - Nanomaterial PY - 2021 AN - OPUS4-53826 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Juds, Carmen T1 - Biocombinatorially selected peptide-polymer conjugates as polypropylene binders N2 - Peptide-polymer bioconjugates combine oligopeptides with synthetic polymer blocks and can be used for various applications in material sciences. In recent years, bioconjugates were applied as compatibilizers and coatings. Biocombinatorial approaches, such as phage display, have been shown to yield strong binding peptides, which exhibit excellent coating properties as peptide-PEO conjugates. Phage display represents a widely exploited strategy to select peptides or proteins that exhibit highly specific affinity to various substrates. Following a phage display experiment, DNA sequencing of binding phage clones is required in order to get the sequence information of the binding peptides. Traditionally, random clone picking followed by Sanger sequencing was applied. However, this method may not necessarily identify the strongest binding clones. Next-generation sequencing made sequencing of whole phage libraries possible, which highly improved the selection of strong binders. Here, we show that the biocombinatorial method of phage display combined with next generation DNA sequencing of whole phage libraries represents a powerful tool for an application in material chemistry. Phage display is used to find specific target binding peptides for polypropylene surfaces (PP). PP binders are of particular interest because thus far gluing or printing on PP is challenging due to its low surface energy. Scripts for sequence data analysis were developed and promising sequences were synthesized as peptide-PEO conjugates. Fluorescence based adsorption experiments on PP surfaces led to the identification of strong binding sequences and a better understanding of the peptide-surface interactions. T2 - 257th National Meeting of the American-Chemical-Society (ACS) CY - Orlando, FL, USA DA - 31.03.2019 KW - Peptides KW - Surfaces KW - Phage Display KW - Peptide Library KW - Screening KW - Glue KW - Paint KW - Polyethylene Glycol KW - PEG KW - Next Generation Sequencing PY - 2019 AN - OPUS4-48837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - The Single Chain Architecture of (Bio)Polymers in Contact with Nanoplastics N2 - In contrast to microplastics, little is known about nanoplastics (1 to 100 nm). In order to make the dectecability of nanoplasics more reliable, we started to develop nanoplastic reference materials. This project also aims to anser the question of how the single chain conformation of bio(polymers) changes in contact with nanoplastics. Small-angle X-ray and neutron scattering methods are suitable methods for studing this topic. Recently the soft and hard interactions between polystyrene nanoplasics and human serum albumin corona was investigated with small-angle neutron scattering. Here we concentrate on small-angle X-ray scattering as our favorite method to study how (bio)polymers change their conformation in contact with nanoplastics. The scattering of bovine serum albumin in its native state can be detected easily. The scattering pattern of this biopolymer changes dramatically when its globular stucture changes to a coil structure. Modeling of chain conformations and the calculation of the scattering pattern is relatively easy to perform. Numerous model calculations will be provided to predict the changes of conformation of single bio(polymer) chains when in conatact with nanoplastics. These predictions will be compared with recent experimenal results from in situ measurments of bio(polymers) in contact with nanoplastics. The impact of temperature, polymer concentration and salt on the single-chain conformation changes will be discussed. T2 - PolyDays 2019 CY - Berlin, Germany DA - 11.09.2019 KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Protein KW - Nanoplastics PY - 2019 AN - OPUS4-48959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Laser-induced periodic surface structures: from nanoscaled light localization to applications N2 - In this contribution the current state in the field of Laser-Induced Periodic Surface Structures (LIPSS) is reviewed. This includes the mechanisms of formation and current applications, particularly the colorization of technical surfaces, the control of surface wetting properties, the tailoring of surface colonization by bacterial biofilms, and the improvement of the tribological performance of nanostructured metal surfaces. T2 - PHOTONICA 2019 - The Seventh International School and Conference on Photonics CY - Belgrade, Serbia DA - 26.08.2019 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser KW - Surface functionalization PY - 2019 UR - http://www.photonica.ac.rs/docs/PHOTONICA2019-Book_of_abstracts.pdf AN - OPUS4-48836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hildebrandt, Jana T1 - PP and PE nanoplastics in water N2 - Plastic debris in micron and nanometer scale pollutes the nature all over the world. The potential dangers of these pollutants remain unpredictable. While risk assessment studies on microplastics are already popular, nanoplastic has not yet reached the same focus of investigation. The reason for this difference is simple: There is a "methodological gap" in the analytics of plastic particles with a diameter smaller than 1 μm. Submicron and nanoplastic particles are currently not detectable in environmental matrices. Therefore, it is important for researchers to have a well-characterized nanoplastic material, that serves as a reference for nanoplastics found in nature. Our aim was to synthesize nanoplastics made from the most common used plastics such as polypropylene (PP) and polyethylene (PE). We found an easy way to form nanoparticles consisting of PP and PE (nano-PP/PE). Herein, nano-PP/PE was formed via a top-down method where the polymer was dispersed to acetone and then transferred to water. No surfactant is needed to obtain a dispersion which is stable for more than 35 weeks. The success of forming nanoplastics and their size was detected via scattering methods, predominantly dynamic light scattering. The chemical analysis of the nanoplastics was performed via Fourier Transform Infrared spectroscopy. Furthermore, electron microscopy was used to complement the results. To examine the good stability of the nanoparticles, zeta potential measurements were performed, which revealed zeta potentials of -30 to -40 mV. T2 - IUPAC-MACRO2020+ CY - Online meeting DA - 17.05.2021 KW - Nanoplastic PY - 2021 AN - OPUS4-53774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Advanced Characterization of the Surface Morphology and Chemistry within nano@BAM N2 - Both essential aspects of the surface of solid matter, its morphology and chemistry, are studied traditionally at BAM starting in the 60’s with different cyclical research focus areas, mostly related either to applicative research or method development. In the recent years, the focus has shifted almost exclusively to the nano-analytics of advanced materials such as complex nanoparticles, (ultra)thin films/coatings, nanocomposites, 2D materials, energy materials, etc. This is also the reason why BAM has established recently the new Competence Center nano@BAM (www.bam.de/Navigation/DE/Themen/Material/Nanotechnologie/sichere-nanomaterialien.html) with the five sub-fields nanoCharacterisation, nanoMaterial, nanoSafety, nanoData and nanoTechnology. The link to the BAM central guidelines to the safety in technology and chemistry is given by the development of reference products such as reference measurement procedures, reference (nano)materials, and newly reference data sets. Thus, an internationally well-networked group in surface analysis has been established @BAM, with regular contributions to integral analytical characterization with metrological and standardization background. Examples of newly developed methodical approaches will be given with an emphasis on correlative nano-analysis of morphology and chemistry of nanomaterials. Correlative imaging by STEM-in-SEM with high-resolution SEM and EDX, and further with AFM or the new technique TKD (Transmission Kikuchi Diffraction) will be explained on various examples of nanostructures, both as starting materials and embedded/functionalized nanoparticles in products. The unique analytical benefits of the Auger electron probe as a veritable nano-tool for surface chemistry will be highlighted. The panoply of advanced surface characterization methods @BAM is completed by discussing examples of hybrid analysis of the bulk of nanomaterials by X-ray Spectroscopy with the highest surface-sensitive methods X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). Particularly for the analysis of the surface chemistry of nanostructures, such as the completeness of the shells of core-shell nanoparticles or in-depth and lateral gradients of chemistry within mesoporous thin layers, the latter methods are inherent. Other special developments like approaches for the quantitative determination of the roughness of particle surface by electron microscopy or for the quantitative determination of the porosity of thin mesoporous layers by electron probe microanalysis (EPMA) with SEM will be presented in conjunction with the corresponding advanced materials studied. Current research projects, promising ideas, including ongoing (pre-)standardization activities in the field of the challenging nano/surface analysis will be touched systematically, with the open goal of identifying future bilateral cooperation possibilities between EMPA and BAM. T2 - EMPA-Kolloquium CY - Online meeting DA - 01.12.2021 KW - Nanoparticles KW - Nano@BAM KW - Nanomaterials KW - Surface morphology and chemistry KW - Correlative analysis PY - 2021 AN - OPUS4-54039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Florian, Camilo T1 - Influence of oxidation in the formation and performance of laser-induced periodic surface structures N2 - The fabrication of laser-induced periodic surface structures (LIPSS) has been reported for metallic, semiconductor and dielectric materials when irradiated with linearly polarized ultrashort laser pulses. Different sets of processing parameters have been identified and extensively studied, allowing the use of LIPSS for applications in medicine, tribology and surface wetting to name a few. One important parameter that is often not considered is the laser-induced oxidation that is produced especially when oxidation prone materials are irradiated in air environment. This surface oxidation can potentially influence the final structures size, shape and orientation and modify their functionality in some specific applications. In this work, we first study the influence of the laser-induced oxidation layer on the formation of LIPSS by characterizing the response of the oxidation prone hard-coating material chromium nitride. Moreover, we employ complementary surface and depth-profiling analytic techniques to reveal morphological, chemical and structural features of different types of surface structures and LIPSS produced on titanium-based substrates. Finite-difference time-domain (FDTD) calculations finally explain how this superficial oxidation layer promotes the formation of a new type of low spatial frequency LIPSS. Also, we measure the depth-extent of the different oxides formed and demonstrate its beneficial influence for friction reduction and wear resistance applications. T2 - SPIE Photonics West Conference, Symposium "Laser-Based Micro- and Nano-Processing XVI" CY - San Francisco, CA, USA DA - 22.01.2022 KW - Laser-induced periodic surface structures (LIPSS) KW - Oxidation KW - Femtosecond laser KW - Laser processing KW - Finite-difference time-domain calculations (FDTD) PY - 2022 AN - OPUS4-54322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Rades, Steffi A1 - Natte, Kishore A1 - Unger, Wolfgang T1 - NanoValid D.5.47 Annex 1, Inter-laboratory comparison on measurand particle size/particle size distribution - Report of the results N2 - An inter-laboratory comparison on the particle size, expressed as mean diameter d, of nanoscaled SiO2 (#14 BAM Silica (see NanoValid DoW, D.5.41/5.42)) has been performed. The majority of participants used Dynamic Light Scattering (DLS). A few used Electron Microscopy as method. Following methods had been applied by only one partner, respectively: Small Angle X-ray Scattering, Analytical Ultracentrifugation, Atomic Force Microscopy and Atomizer with electric mobility spectrometer. KW - Nanoparticle size measurement KW - Silica nanoparticles KW - Inter-laboratory comparison KW - EU FP7 project NanoValid PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-488117 DO - https://doi.org/10.5281/zenodo.3380570 SP - 1 EP - 23 PB - Zenodo CY - Geneva AN - OPUS4-48811 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Esmann, M. A1 - Chimeh, A. A1 - Korte, A. A1 - Zhong, J. A1 - Stephan, S. A1 - Witt, Julia A1 - Wittstock, G. A1 - Talebi, N. A1 - Lienau, C. T1 - Plasmonic nanofocusing spectral interferometry N2 - We describe and demonstrate a novel experimental approach to measure broadband, amplitude- and phase-resolved scattering spectra of single nanoparticles with 10-nm spatial resolution. Nanofocusing of Surface plasmon polaritons (SPPs) propagating along the shaft of a conical gold taper is used to create a spatially isolated, spectrally broad nanoscale light source at ist very apex. The interference between these incident SPPs and SPPs that are backpropagating from the apex leads to the formation of an inherently phase-stable interferogram, which we detect in the far field by partially scattering SPPs off a small protrusion on the taper shaft. We show that these interferograms allow the reconstruction of both the amplitude and phase of the local optical near fields around individual nanoparticles optically coupled to the taper apex. We extract local light scattering spectra of particles and quantify line broadenings and spectral shifts induced by tip-sample coupling. Our experimental findings are supported by corresponding finite-difference time-domain and coupled dipole simulations and Show that, in the limit of weak tip-sample coupling, the measurements directly probe the projected local density of optical states of the plasmonic system. The combination of a highly stable inline interferometer with the inherent optical background suppression through nanofocusing makes it a promising tool for the locally resolved study of the spectral and temporal optical response of coupled hybrid nanosystems. KW - Plasmonic nanofocusing KW - Near-field spectroscopy PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504985 DO - https://doi.org/10.1515/nanoph-2019-0397 VL - 9 IS - 2 SP - 491 EP - 508 PB - De Gruyter AN - OPUS4-50498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knigge, Xenia T1 - First Experiences with the new HAXPES@BAM N2 - This talk was part of the inauguration event for the new x-ray photoelectron spectrometer with the possibility to measure HAXPES (hard energy x-ray photoelectron spectroscopy). With HAXPES detailed chemical information can now be gained not only from the first outermost nanometres of the sample surface, but also from deeper regions. In this talk first results and experiences handling the spectrometer are shown. T2 - Inauguration of the HAXPES@BAM - A new Hard-X-Ray Photoelectron Spectrometer CY - Online meeting DA - 25.01.2022 KW - HAXPES KW - Nano@BAM KW - Surface Analysis KW - XPS PY - 2022 UR - https://www.bam.de/Content/EN/Events/2022/2022-01-25-hapex.html AN - OPUS4-54434 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liebig, F. A1 - Sarhan, R. M. A1 - Schmitt, C. N. Z. A1 - Thünemann, Andreas A1 - Prietzel, C. A1 - Bargheer, M. A1 - Koetz, J. T1 - Gold Nanotriangles with Crumble Topping and their Influence on Catalysis and Surface‐Enhanced Raman Spectroscopy N2 - By adding hyaluronic acid (HA) to dioctyl sodium sulfosuccinate (AOT)‐stabilized gold nanotriangles (AuNTs) with an average thickness of 7.5±1 nm and an edge length of about 175±17 nm, the AOT bilayer is replaced by a polymeric HA‐layer leading to biocompatible nanoplatelets. The subsequent reduction process of tetrachloroauric acid in the HA‐shell surrounding the AuNTs leads to the formation of spherical gold nanoparticles on the platelet surface. With increasing tetrachloroauric acid concentration, the decoration with gold nanoparticles can be tuned. SAXS measurements reveal an increase of the platelet thickness up to around 14.5 nm, twice the initial value of bare AuNTs. HRTEM micrographs show welding phenomena between densely packed particles on the platelet surface, leading to a crumble formation while preserving the original crystal structure. Crumbles crystallized on top of the platelets enhance the Raman signal by a factor of around 20, and intensify the plasmon‐driven dimerization of 4‐nitrothiophenol (4‐NTP) to 4,4′‐dimercaptoazobenzene in a yield of up to 50 %. The resulting crumbled nanotriangles, with a biopolymer shell and the absorption maximum in the second window for in vivo imaging, are promising candidates for biomedical sensing. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle KW - Gold PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503977 DO - https://doi.org/10.1002/cplu.201900745 VL - 85 IS - 3 SP - 519 EP - 526 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-50397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -