TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Mielke, Johannes A1 - Dohányosová, P. A1 - Müller, P. A1 - López-Vidal, S. A1 - Hodoroaba, Vasile-Dan T1 - Electrospray as a sample preparation tool for electron microscopy: Toward quantitative evaluation of nanoparticles N2 - Electrospray ionization constitutes a promising deposition technique for high-resolution imaging. Particle distribution on TEM grids takes place homogeneously and no losses occur. Suspension must be appropriate (stabilizer may induce artefacts). ESI parameters need to be optimized for each material. T2 - Final NanoDefine Outreach Event: Classification of nanomaterials according to the EU definition CY - Brüssel, Belgium DA - 19.09.2017 KW - Electrospray deposition KW - Electron microscopy KW - Nanoparticles PY - 2017 UR - http://www.nanodefine.eu/index.php/nanodefine-meetings/125-final-outreach-event-2017 AN - OPUS4-42508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Wohlleben, W. A1 - Mielke, Johannes A1 - Rauscher, H. T1 - Volume specific surface area (VSSA) by BET: concept and demonstration on industrial materials N2 - Volume specific surface area (VSSA) as measured by BET constituites a simple and reliable solution to (most) powders. Porous, coated, polydisperse/multimodal materials are to be treated with care, i.e. doubled by analysis with electron microscopy or more advanced BET analysis (e.g. t-plot)for each material in part. T2 - Final NanoDefine Outreach Event: Classification of nanomaterials according to the EU definition CY - Brüssel, Belgium DA - 19.09.2017 KW - VSSA KW - BET KW - Nanoparticles KW - Powder KW - Nanomaterial classfication PY - 2017 UR - http://www.nanodefine.eu/index.php/nanodefine-meetings/125-final-outreach-event-2017 AN - OPUS4-42509 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Hodoroaba, Vasile-Dan A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Borghetti, P. A1 - Garcia, S. A1 - Gómez, E. A1 - Blanco, M. A1 - Alberto, Gabriele A1 - Martra, G. T1 - Organic surface modification and analysis of titania nanoparticles for self-assembly in multiple layers N2 - Parameters of TiO2 coatings can greatly influence their final performance in largescale applications such as photocatalytic measurements, orthopedic and/or dental prostheses, cell cultures, and dye-sensitized solar cells. From different film deposition procedures, self-assembly of TiO2 NPs in multiple layers was selected for systematic characterization. EDX, AES and ToF-SIMS analysis have been carried out in order to evaluate the functionalization of several types of TiO2 NPs differing in size, shape and surface area. KW - TiO2 KW - Nanoparticles KW - Surface modification KW - Functionalization PY - 2017 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/organic-surface-modification-and-analysis-of-titania-nanoparticles-for-selfassembly-in-multiple-layers/66776A4CA7FD059CE39041A99A922D90 DO - https://doi.org/10.1017/S1431927617010029 SN - 1431-9276 SN - 1435-8115 VL - 23 IS - S1 (July) SP - 1872 EP - 1873 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-42457 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mielke, Johannes A1 - Dohányosová, P. A1 - Müller, P. A1 - Lopez, S. A1 - Hodoroaba, Vasile-Dan T1 - Electrospray as a sample preparation tool for electron microscopic investigations: Toward quantitative evaluation of nanoparticles N2 - The potential of electrospray deposition, for the controlled preparation of particles for imaging in electron microscopes, is evaluated on various materials: from mono-modal suspensions of spherical particles to multimodal suspensions and to real-world industrial materials. It is shown that agglomeration is reduced substantially on the sample carrier, compared with conventional sample preparation techniques. For the first time, it is possible to assess the number concentration of a tri-modal polystyrene suspension by electron microscopy, due to the high deposition efficiency of the electrospray. We discovered that some suspension stabilizing surfactants form artifact particles during electrospraying. These can be avoided by optimizing the sprayed suspension. KW - Electrospray deposition KW - Nanoparticles KW - SEM KW - TEM KW - Sample preparation PY - 2017 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/electrospray-as-a-sample-preparation-tool-for-electron-microscopic-investigations-toward-quantitative-evaluation-of-nanoparticles/483B212FF290B7EC001A212A19E4E72A DO - https://doi.org/10.1017/S1431927617010145 SN - 1435-8115 SN - 1431-9276 VL - 23 IS - S1 (July) SP - 1896 EP - 1897 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-42453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Advanced methods for nanomaterial characterization N2 - At the Final Outreach Event of the European FP7 NanoDefine project the results achieved during 4 years of intensive research and development work (2013-2017) with relevant stakeholders and wider community, and their practical implications and impact are presented and discussed. The newly developed particle-size related measurement tools and their practical suitability and applicability to classify materials, formulations and products according to the EC recommendation on the definition of a nanomaterial (2011/696/EU) are demonstrated. T2 - Final Outreach Event “Classification of nanomaterials according to the EU definition” CY - Brüssel, Belgium DA - 19.09.2017 KW - Nanomaterial KW - Nanoparticles KW - Particle sizing techniques KW - Nanomaterial classification PY - 2017 AN - OPUS4-42390 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Mielke, Johannes A1 - Dohányosová, P. A1 - Müller, P. A1 - López-Vidal, S. T1 - Deposition of nanoparticles by electrospray for improved analysis by SEM/TEM and EDX N2 - Of many experimental techniques for measuring particle sizes and size distributions, electron microscopy (EM) is still considered as the gold standard, especially in the nano range (1–100 nm). Furthermore, high-resolution X-ray spectroscopy (EDX) in conjunction with EM can be applied to individul NPs. Preparation of an EM sample for generic particulate materials is a difficult task. Usually, the particles in a suspension are deposited on a support. However, this procedure includes the drying of larger solvent amounts on the substrate itself, and this can affect the spatial distribution of the deposited particles. One possibility to overcome this is the use of an electrospray system, where the suspension of particles is sprayed onto the substrate in charged droplets that are so small that they either dry off on the substrate immediately without affecting the position of particles, or even already during their flight time to the substrate. Additionally, the charging of particles minimizes agglomeration and aggregation, maximizing the collection of the EM grids. The prototype of an electrospray deposition System was tested. Electrospray is theoretically described since a long time, but no dedicated commercial instruments are available for the preparation of TEM grids yet, apart from electrostatic deposition of aerosols. Several materials have been sprayed onto TEM grids and the resulting particle distributions were evaluated. Operation parameters such as the sample flow-rate, capillary – substrate distance, electric field strength and sampling period length have been optimized. It was found that the particles deposited by electrospray generally show a much more homogeneous spatial distribution on the substrate and a substantial increase of the number of single particles (suited to automatic analysis). T2 - 17th European Conference on Applications of Surface and Interface Analysis (ECASIA 2017) CY - Montpellier, France DA - 24.09.2017 KW - Electrospray deposition KW - Nanoparticles KW - SEM KW - TEM KW - TEM grid PY - 2017 AN - OPUS4-42393 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wollschläger, Nicole A1 - Häusler, Ines A1 - Ortel, Erik A1 - Hodoroaba, Vasile-Dan A1 - Palasse, L. A1 - Dirscherl, K. T1 - Characterization of porous, TiO2 nanoparticle films using on-axis TKD in SEM – a new nano-analysis tool for a large-scale application N2 - A combined methodical approach is tested with respect to the characterization of the inner structure of porous TiO2 layers as typically used in modern dye sensitized solar cells (DSSC). Their performance is directly linked to the surface area of the pore network. The micrometer thick layer employed was manufactured by screen-printing of a starting TiO2 powder constituted of shape-controlled, bipyramidal anatase nanoparticles on FTO/glass substrates. The analytical methods exploited in our study are Focused Ion Beam (FIB) slicing followed by 3D reconstruction as well as the new approach transmission Kikuchi diffraction (TKD) technology in the scanning electron microscope (SEM). Size and shape distribution of the TiO2 NPs within the layer can be extracted. SEM in transmission mode and atomic force microscopy (AFM) have been used to verify the dimensional data obtained by the new combined methodical approach. Its analytical benefits but also the challenges and limitations are highlighted. KW - TiO2 KW - TKD KW - Particle size distribution KW - Nanoparticles KW - Porous film PY - 2017 UR - https://www.cambridge.org/core/services/aop-cambridge-core/content/view/8A8B29335A2F4D0CB6922F6F5A19C5DC/S1431927617003397a.pdf/characterization_of_porous_tio2_nanoparticle_films_using_onaxis_tkd_in_sem_a_new_nanoanalysis_tool_for_a_largescale_application.pdf DO - https://doi.org/10.1017/S1431927617003397 VL - 23 IS - S1 (July) SP - 542 EP - 543 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-41924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jakubowski, Norbert A1 - Müller, L. A1 - Traub, Heike A1 - Esteban-Fernández, D. A1 - Panne, Ulrich A1 - Wanka, Antje A1 - Schellenberger, E. A1 - Theuring, F. A1 - Kneipp, J. T1 - Method development for metal detection at cellular levels N2 - An overview about different analytical approaches will be presented of how to detect metals in individual biological cells by use of ICP-MS. For this purpose, we are using different sample introduction systems for ICP-MS for detection, imaging and quantification of metals at cellular levels. By use of laser ablation, we have studied the up-take by and distribution of nanoparticles in single cells. Recently we have developed staining techniques to measure protein and DNA content of cells and identifying the cell status by immunoassays using metal-tagging of antibodies. New research based on cell arrays will be shortly discussed. Using pneumatic nebulization and microdroplet generation, we have also studied the up-take of nanoparticles and toxic metals as well as essential elements in single cells using different ICP-MS mass spectrometric concepts (sector field instrument, triple-quad instrument, time of flight (CyTOF) instrument). The different ICP-MS based methods will be compared concerning their analytical figures of merit and their strengths and weaknesses will be evaluated. T2 - Metallomics 2017 CY - Vienna, Austria DA - 14.08.2017 KW - Single cell analysis KW - Laser ablation KW - Nanoparticles KW - ICP-MS PY - 2017 AN - OPUS4-41690 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Oswald, F. A1 - Narbey, S. A1 - Radnik, Jörg T1 - Complementary methodical approach for the analysis of a perovskite solar cell layered system N2 - Loss in efficiency of perovskite solar cells may be caused by structural and/or chemical alterations of the complex layered system. As these changes might take place either in the bulk and/or on the surface of the stratified material, analytical tools addressing both key issues are selected and combined. SEM/EDX combined with XPS were chosen as appropriate methodical approach to characterise perovskite laboratory cells in depth and complementary on top, before and after light exposure. The layered perovskite system investigated here is based on glass covered with fluorine doped tin oxide (FTO), followed by three porous thin films of TiO2, ZrO2 and a thick monolithic carbon. The TiO2 film is subdivided into a dense layer covered by a porous one constituted of nanoparticles with a truncated bipyramidal shape. This layered system serves as the matrix for the perovskite. After infiltration of perovskite solution and annealing, EDX spectral maps on cross-sections of the specimen have been measured. The distribution of relevant elements – Si, Sn, Ti, Zr and C – correlates conclusively with layers visible in the acquired SEM images. Lead and iodine are distributed throughout the porous layers C, ZrO2 and TiO2. In a SEM micrograph taken of the cross-section of a sample after illumination, the glass substrate and all layers FTO, TiO2, ZrO2 as well as C are clearly identified. By EDX it was found that several weeks of ambient daylight did not change significantly the qualitative elemental composition of lead and iodine throughout the solar cell system. It was confirmed with EDX that nanoparticles identified in high-resolution SEM micrographs contain mainly Pb and I, indicating these to be the perovskite crystals. However, a time-dependent compositional and chemical altering was observed with XPS for the near-surface region of the outermost ~10 nm after two months of illumination. T2 - Microscopy & Microanalysis 2017 Meeting CY - St. Louis, MO, USA DA - 06.08.2017 KW - Thin films KW - EDX KW - XPS KW - SEM KW - Nanoparticles KW - Perovskite KW - TiO2 PY - 2017 AN - OPUS4-41664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Wollschläger, Nicole A1 - Pallase, L. A1 - Häusler, Ines A1 - Ortel, Erik A1 - Dirscherl, K. T1 - Characterization of Porous, TiO2 Nanoparticle Films Using On-Axis TKD in SEM – a New Nano-Analysis Tool for a Large-Scale Application N2 - A combined methodical approach is tested with respect to the characterization of the inner structure of porous TiO2 layers as typically used in modern dye sensitized solar cells (DSSC). Their performance is directly linked to the surface area of the pore network. The micrometer thick layer employed was manufactured by screen-printing of a starting TiO2 powder constituted of shape-controlled, bipyramidal anatase nanoparticles on FTO/glass substrates. The analytical methods exploited in our study are Focused Ion Beam (FIB) slicing followed by 3D reconstruction as well as the new approach transmission Kikuchi diffraction (TKD) technology in the scanning electron microscope (SEM). Size and shape distribution of the TiO2 NPs within the layer can be extracted. SEM in transmission mode and atomic force microscopy (AFM) have been used to verify the dimensional data obtained by the new combined methodical approach. Its analytical benefits but also the challenges and limitations are highlighted. T2 - Microscopy & Microanalysis 2017 Meeting CY - St. Louis, MO, USA DA - 06.08.2017 KW - Porous layers KW - TiO2 KW - Nanoparticles KW - Size and shape distribution KW - TKD KW - SEM PY - 2017 AN - OPUS4-41660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Borghetti, P. A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Garcia, S. A1 - Gómez, E. A1 - Blanco, M. A1 - Alberto, Gabriele A1 - Martra, G. T1 - Organic surface modification and analysis of TiO2 nanoparticles for self-assembly in multiple layers N2 - Parameters of TiO2 coatings can greatly influence their final performance in largescale applications such as photocatalytic measurements, orthopedic and/or dental prostheses, cell cultures, and dye-sensitized solar cells. From different film deposition procedures, self-assembly of TiO2 NPs in multiple layers was selected for systematic characterization. EDX, AES and ToF-SIMS analysis have been carried out in order to evaluate the functionalization of several types of TiO2 NPs differing in size, shape and surface area. T2 - Microscopy & Microanalysis 2017 Meeting CY - St. Louis, MO, USA DA - 06.08.2017 KW - TiO2 KW - Nanoparticles KW - EDX KW - ToF-SIMS KW - XPS KW - Auger electron spectroscopy KW - Functionalization PY - 2017 AN - OPUS4-41662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Mielke, Johannes A1 - Dohányosová, P. A1 - Müller, P. A1 - López-Vidal, S. T1 - Electrospray as a sample preparation tool for electron microscopic investigations: Toward quantitative evaluation of nanoparticles N2 - The potential of electrospray deposition, for the controlled preparation of particles for imaging in electron microscopes, is evaluated on various materials: from mono-modal suspensions of spherical particles to multimodal suspensions and to real-world industrial materials. It is shown that agglomeration is reduced substantially on the sample carrier, compared with conventional sample preparation techniques. For the first time, it is possible to assess the number concentration of a tri-modal polystyrene suspension by electron microscopy, due to the high Deposition efficiency of the electrospray. We discovered that some suspension stabilizing surfactants form artifact particles during electrospraying. These can be avoided by optimizing the sprayed suspension. T2 - Microscopy & Microanalysis 2017 Meeting CY - St. Louis, MO, USA DA - 06.08.2017 KW - Electrospray deposition KW - Nanoparticles KW - Electron microscopy KW - Sample preparation KW - TEM KW - SEM PY - 2017 AN - OPUS4-41578 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Usmani, Shirin A1 - Schlishka, Joerg A1 - Klutzny, Kerstin A1 - de Laval, Yvonne A1 - Plarre, Rüdiger A1 - Krahl, Thoralf A1 - Stephan, Ina A1 - Huebert, Thomas A1 - Kemnitz, Erhard T1 - Wood protection with nanoparticles: MgF2 and CaF2 N2 - Alkaline earth metal fluoride nanoparticles have been investigated for application in wood protection. Sols of MgF2 and CaF2 were synthesized and their efficacy was tested against fungi and termites (Rehmer 2016, Krahl et al. 2016). The sols were characterized by XRD and SEM. The wood specimens were vacuum impregnated with nanoparticles and then exposed to fungi and termites according to EU certified test conditions. Our results show that wood impregnated with metal fluoride nanoparticles significantly reduce cellulose hydrolysis by fungi and termites. The wood samples were exposed to brown-rot fungi; Coniophora puteana and Poria placenta. Between the two fungi, the overall mass lost due to fungal degradation was lower for treated (MgF2 and CaF2) wood samples exposed to Coniophora puteana. Thus, the metal fluoride nanoparticles impregnated in the wood samples were more efficient in reducing cellulose degradation from Coniophora puteana than from Poria placenta. However the mass loss in samples treated with MgF2 was similar to those treated with CaF2, irrespective of type of fungi. Therefore, it is likely that fungal degradation in treated samples was dependent on the biocidal action of fluorides rather than on the differences in chemical and physical properties of MgF2 and CaF2, respectively. Conversely, for termite exposure, wood samples treated with MgF2 had lower cellulose degradation compared to those treated with CaF2. A possible explanation for this difference in results could be fungi and termites use separate mechanisms for cellulose hydrolysis which will be further investigated. Future experiments include testing the leaching potential of MgF2 and CaF2 nanoparticles from wood. The results from the leaching experiment will test if metal fluoride nanoparticles can provide long-term and environmentally safe protection to wood. T2 - International Research Group (IRG48) Scientific Conference on Wood Protection CY - Ghent, Belgium DA - 04.06.2017 KW - Fluoride KW - Nanoparticles KW - Brown-rot fungi KW - Termites PY - 2017 AN - OPUS4-41019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit A1 - Unger, Wolfgang T1 - Exploring the capabilities of near ambient pressure XPS: Characterisation of biofilms and nanoparticles in solution N2 - Seminar-talk for "Ausgewählte analytische Methoden der Physik " at TU Berlin. A introduction about near-ambient pressure XPS is given, furhter, results from measurements of biofilms and dispersed nanoparticles are presented and discussed. T2 - Seminar AG Kanngießer: Ausgewählte analytische Methoden der Physik CY - Technische Universität, Berlin, Germany DA - 04.07.2017 KW - Alginate KW - NAP-XPS KW - Nanoparticles KW - Biofilms KW - E. coli PY - 2017 AN - OPUS4-40905 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - NanoDefine – a brief overview N2 - The large European nanometrology Project NanoDefine is presented briefly with respect to the challenges of measurement of particle size distribution for complex nanoparticulate materials. The methods chosen for a tiered approach for the classification of a nanomaterial are discussed with regard to their peformance. Representative resuls on real life, complex shaped nanoparticulate materials are shown. The recently initiated VAMAS inter-laboratory comparisons to determine the reproducibility necessary for international standardisation have been also presented. T2 - Metrology Study Group of ISO/TC 229 Nanotechnologies /JWG2 'Measurement and Characterization' CY - Tokyo, Japan DA - 31.05.2017 KW - EU definition of a nanomaterial KW - Nanomaterial classification KW - Nanoparticles KW - Nanoparticle size distribution KW - VAMAS inter-laboratory comparison KW - Particle sizing techniques PY - 2017 AN - OPUS4-40475 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Available particle-sizing techniques at work for the classification as a nanomaterial - How reliable it really is? N2 - The capability of currently available particle sizing techniques for reliable classification of materials that potentially fall under the EU Definition of a nanomaterial is discussed. A systematic quantitative evaluation of the sizing techniques is presented together with representative case studies of analysis of industrially relevant materials. Recommendations on the most appropriate and efficient use of techniques for different types of material are given. T2 - Frontiers of Nanomaterial Characterization CY - Tokyo, Japan DA - 28.05.2017 KW - Nanomaterial classification KW - Nanoparticles KW - Number-weighted median size KW - Particle size analysis KW - Characterization techniques PY - 2017 AN - OPUS4-40474 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rades, Steffi A1 - Ortel, Erik A1 - Wirth, Thomas A1 - García, Sarai A1 - Gómez, Estibaliz A1 - Blanco, Miren A1 - Alberto, Gabriele A1 - Martra, Gianmario A1 - Hodoroaba, Vasile-Dan T1 - Surface and in-depth analysis of functionalization of TiO2 nanoparticles for self-assembly in multiple layers N2 - Parameters of TiO2 coatings can greatly influence their final performance in largescale applications such as photocatalytic measurements, orthopedic and/or dental prostheses, cell cultures, and dye-sensitized solar cells. From different film deposition procedures, self-assembly of TiO2 NPs in multiple layers was selected for systematic characterization. EDX, AES and ToF-SIMS analysis have been carried out in order to evaluate the functionalization of several types of TiO2 NPs differing in size, shape and surface area. T2 - EMAS 2017 - 15th European Workshop on MODERN DEVELOPMENTS AND APPLICATIONS IN MICROBEAM ANALYSIS and IUMAS-7 Meeting CY - Constance, Germany DA - 07.05.2017 KW - Functionalization KW - Surface analysis KW - Nanoparticles KW - Thin films PY - 2017 AN - OPUS4-40266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rades, Steffi A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Holzweber, Markus A1 - Pellegrino, F. A1 - Martra, G. A1 - Hodoroaba, Vasile-Dan T1 - Tracing fluorine at the surface and in the bulk of TiO2 nanoplatelets by means of SEM-EDX, AES and ToF-SIMS N2 - The synthesis of TiO2 nanoplatelets with fluorine-containing reactants is carried out using titanium (IV) butoxide as precursor and concentrated HF as shape controller, the final product requires a working up in order to eliminate or at least to reduce the amount of residual fluorides, which is realized here by well-defined thermal treatment of the samples. Bulk and surface sensitive methods namely scanning electron microscopy with energydispersive X-ray spectroscopy (SEM-EDX), Auger electron spectroscopy (AES) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) have been applied to trace the presence of any fluorides in dependence on different information depths and measurement sensitivities of these methods. T2 - EMAS 2017 - 15th European Workshop on MODERN DEVELOPMENTS AND APPLICATIONS IN MICROBEAM ANALYSIS and IUMAS-7 Meeting CY - Konstanz, Germany DA - 07.05.2017 KW - Nanoparticles KW - Surface analysis KW - ToF-SIMS KW - AES KW - SEM-EDX PY - 2017 AN - OPUS4-40265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Mielke, Johannes A1 - Dohányosová, P. A1 - Müller, P. A1 - López-Vidal, S. T1 - Improved Deposition of Nanoparticles vy Electrospray Analaysis with SEM/TEM and EDS N2 - Although there are many experimental techniques for measuring particle sizes and size distributions, electron microscopy (EM) is still considered as the gold standard in this field, especially when it comes to particle sizes in the nanorange (1 nm – 100 nm). Furthermore, high-resolution X-ray spectroscopy (EDS) can be applied to individual nanoparticles. To be able to extract accurate information from the EM micrographs and EDS elemental maps that are representative for the material under investigation, one needs to assure the representativity of the particles as sampled on the substrate and their homogeneous spatial distribution, to avoid operator bias when selecting the imaged area. Furthermore, agglomeration should be avoided as far as possible. Several sample preparation techniques exist since a long time, the most common way being suspending the particles in a liquid and depositing them on the grid. However, this procedure includes the drying of larger solvent amounts on the substrate itself, which can affect the spatial distribution of the deposited particles. One possibility to overcome this problem is the use of an electrospray system, where the suspension of particles is sprayed onto the substrate in charged droplets that are so small that they either dry off on the substrate immediately without affecting the position of particles, or even already during their flight time to the substrate. No dedicated commercial instruments are available for the preparation of TEM grids yet, only electrostatic deposition of aerosols on TEM grids has been reported so far. To test the prototype and assess its performance, several materials have been sprayed onto TEM grids and the resulting particle distributions were compared to more traditional sample preparation strategies like the “drop on grid” method. Operation parameters such as the sample flow-rate, capillary – substrate distance, electric field strength and sampling period length have been optimised. It was found that the particles deposited by electrospray generally show a much more homogeneous spatial distribution on the substrate and a substantial increase of the number of single particles, which are much better suited to an automatic image evaluation procedure than the agglomerated particles observed otherwise. The applicability of the technique to a broad range of materials is demonstrated by various examples, but also the influence of the substrate, the choice of the particular TEM grid, on the obtained spatial particle distribution is assessed. T2 - EMAS 2017 - 15th European Workshop on MODERN DEVELOPMENTS AND APPLICATIONS IN MICROBEAM ANALYSIS and IUMAS-7 Meeting CY - Konstanz, Germany DA - 07.05.2017 KW - Electrospray deposition KW - TEM grids KW - Nanoparticles KW - Agglomeration PY - 2017 AN - OPUS4-40257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Behnke, Thomas A1 - Moser, Marko A1 - Nirmalananthan-Budau, Nithiya A1 - Resch-Genger, Ute T1 - Spectroscopic quantification of surface groups on micro- and nanoparticles N2 - Nanometer- and micrometer-sized particles are of increasing importance for a wide range of applications in the material and life sciences. This includes carriers for, e.g., drugs as well as dye molecules for use as multichromophoric reporters for signal enhancement in optical assays, platforms for DNA sequencing, and the fabrication of nanosensors and targeted probes for bioimaging studies. Application-relevant properties of such particles include their size (and size distribution), shape, colloidal stability, biocompatibility, and ease of subsequent functionalization, e.g., with linkers, sensor molecules, and targeting ligands. The latter requires knowledge of the number of groups effectively accessible for subsequent coupling reactions and hence, selective and sensitive methods of analysis, which can be ideally employed for the characterization of a broad variety of particle systems independent of their optical properties, i.e., scattering or the presence of encoding dyes. For product control, robust, reliable and fast methods performable with inexpensive equipment are prefered. In this respect, we studied a variety of conventional labels for optical readout, utilizing changes in intensity and/or color of absorption and/or emission. In addition, we developed a platform of cleavable and multimodal labels for optical assays which consist of a cleavable linker and an optically active reporter moiety. In contrast to conventional reporters measured directly at the particle surface, which are prone to signal distortions by scattering and encoding dyes, these cleavable labels can be detected colorimetrically or fluorometrically both bound at the particle surface and after quantitative cleavage of the linker in the transparent supernatant. Moreover, they enable straightforward validation by method comparison with elemental analysis, ICP-OES or ICP-MS. Here, we present representative examples of newly synthesized cleavable labels and their application for the quantification of amino, thiol and carboxy surface groups on different nanomaterials and compare these results with measurements using conventional optical labels. T2 - 253rd ACS National Meeting CY - San Francisco, CA, USA DA - 02.04.2017 KW - Nanoparticles KW - Microparticles KW - Surface groups KW - Quantification KW - Cleavable linker PY - 2017 N1 - Geburtsname von Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. - Birth name of Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. AN - OPUS4-40004 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -