TY - CONF A1 - Rades, Steffi T1 - Investigation of Nanoparticles by Auger electron spectroscopy (AES) T2 - 15th European Conference on Applications of Surface and Interface Analysis (ECASIA 13) CY - Cagliari, Italy DA - 2013-10-13 PY - 2013 AN - OPUS4-30131 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - Investigation of silica nanoparticles by Auger electron spectroscopy (AES) N2 - High-priority industrial nanomaterials like SiO2, TiO2, and Ag are being characterized on a systematic basis within the framework of the EU FP7 research project NanoValid. Silica nanoparticles from an industrial source have been analyzed by Auger electron spectroscopy. Point, line, and map spectra were collected. Material specific and methodological aspects causing the special course of Auger line scan signals will be discussed. KW - Nanoparticles KW - Auger electron spectroscopy KW - Surface analysis PY - 2014 DO - https://doi.org/10.1002/sia.5378 SN - 0142-2421 SN - 1096-9918 VL - 46 IS - 10-11 SP - 952 EP - 956 PB - Wiley CY - Chichester AN - OPUS4-31604 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Kalbe, Henryk A1 - Rades, Steffi T1 - Determining shell thicknesses in stabilised CdSe@ZnS core-shell nanoparticles by quantitative XPS analysis using an infinitesimal columns model N2 - A novel Infinitesimal Columns (IC) simulation model is introduced in this study for the quantitativeanalysis of core-shell nanoparticles (CSNP) by means of XPS, which combines the advantages of exist-ing approaches. The IC model is applied to stabilised Lumidot™CdSe/ZnS 610 CSNP for an extensiveinvestigation of their internal structure, i.e. calculation of the two shell thicknesses (ZnS and stabiliser)and exploration of deviations from the idealised CSNP composition. The observed discrepancies betweendifferent model calculations can be attributed to the presence of excess stabiliser as well as synthesisresidues, demonstrating the necessity of sophisticated purification methods. An excellent agreement isfound in the comparison of the IC model with established models from the existing literature, the Shardmodel and the software SESSA. KW - XPS KW - Quantum dot KW - Core shell nano particle PY - 2016 DO - https://doi.org/10.1016/j.elspec.2016.08.002 SN - 0368-2048 VL - 212 SP - 34 EP - 43 PB - Elsevier B.V. AN - OPUS4-38273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rades, Steffi T1 - Automated feature analysis of nanoparticles by high-resolution transmission scanning electron microscopy and energy dispersive X-ray spectroscopy T2 - EuroNanoForum (ENF) 2015 CY - Riga, Lativa DA - 2015-06-09 PY - 2015 AN - OPUS4-33487 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rades, Steffi T1 - Analysis of functionalization of TiO2 nanoparticles and various substrates by means of SEM-EDX, AES and ToF-SIMS N2 - The physico-chemical characteristics of TiO2 coatings can greatly influence their final performance. In SETNanoMetro, different deposition procedures are being set for applying films of TiO2 NPs with defined and homogenous thickness on supports of interest for the applications studied in the project. The selected substrates are the following: (i) Silica glasses for photocatalytic measurements, (ii) Ti-alloys for orthopedic and/or dental prostheses, and for cell cultures, and (iii) Conductive glasses (e.g. Fluorine doped Tin Oxide, FTO) for dye-sensitized solar cells. From the different film deposition procedures studied within the project Self-assembly of TiO2 NPs in multiple layers was selected. For this, surface modification of the substrate and of TiO2 nanoparticles (NPs) with e.g. silane coupling agents is a prerequisite. First attempts to prepare the self-assembled coating on the functionalized glass substrates seem to indicate that the functionalized NPs adhere to the substrates, even if the final coatings were not homogenous and presented agglomerates. ToF-SIMS results support this outcome. In order to use the layer-by-layer deposition technique for the formation of TiO2 films by controlled self-assembly of the TiO2 NPs, the proper complementary moieties for the functionalization of the NPs were chosen. A first set of NPs has been produced by reaction with (3-aminopropyl)phosphonic acid (APPA) in order to functionalize the surface with free amino-groups. Then, the complementary NP set can be obtained from an aliquot of the first one, through the conversion of free surface amino-groups to aldehydes by reaction with glutaraldehyde. A proper approach for the functionalization of two types of TiO2, commercial P25 (Evonik) and SETNanoMetro-sample labelled UT001, with APPA was developed. A second set of NPs consisting of three types of TiO2 NPs, P25 and SETNanoMetro NPs (TiO2 NPs with high specific surface area > 150 m2/g and TiO2 NPs with low size < 20 nm) was functionalized with (3-aminopropyl)triethoxysilane (APTS). As for the previous set of NPs, the complementary NP set was obtained through the conversion of free surface amino-groups to aldehydes by reaction with glutaraldehyde. EDX, AES and ToF-SIMS spectra were collected and analyzed to demonstrate the presence of the surface functionalization of the different types of TiO2 NPs. T2 - Nanoscience meets Metrology - Synthesis, Characterization, Testing and Applications of Validated Nanoparticles - International Summer School CY - Turin, Italy DA - 04.09.2016 KW - Time-of-flight secondary-ion mass spectrometry KW - X-ray spectroscopy KW - Auger electron spectroscopy KW - Electron microscopy KW - Nanoparticles KW - Thin films PY - 2016 UR - http://www.setnanometro.eu/events/ AN - OPUS4-38064 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Orts Gil, Guillermo A1 - Natte, Kishore A1 - Thiermann, Raphael A1 - Girod, Matthias A1 - Rades, Steffi A1 - Kalbe, Henryk A1 - Thünemann, Andreas A1 - Maskos, M. A1 - Österle, Werner T1 - On the role of surface composition and curvature on biointerface formation and colloidal stability of nanoparticles in a protein-rich model system N2 - The need for a better understanding of nanoparticle–protein interactions and the mechanisms governing the resulting colloidal stability has been emphasised in recent years. In the present contribution, the short and long term colloidal stability of silica nanoparticles (SNPs) and silica–poly(ethylene glycol) nanohybrids (Sil–PEG) have been scrutinised in a protein model system. Well-defined silica nanoparticles are rapidly covered by bovine serum albumin (BSA) and form small clusters after 20 min while large agglomerates are detected after 10 h depending on both particle size and nanoparticle–protein ratio. Oppositely, Sil–PEG hybrids present suppressive protein adsorption and enhanced short and long term colloidal stability in protein solution. No critical agglomeration was found for either system in the absence of protein, proving that instability found for SNPs must arise as a consequence of protein adsorption and not to high ionic environment. Analysis of the small angle X-ray scattering (SAXS) structure factor indicates a short-range attractive potential between particles in the silica-BSA system, which is in good agreement with a protein bridging agglomeration mechanism. The results presented here point out the importance of the nanoparticle surface properties on the ability to adsorb proteins and how the induced or depressed adsorption may potentially drive the resulting colloidal stability. KW - Nanoparticles KW - Protein corona KW - Biointerface KW - BSA KW - PEG KW - Colloidal stability PY - 2013 DO - https://doi.org/10.1016/j.colsurfb.2013.02.027 SN - 0927-7765 SN - 1873-4367 VL - 108 SP - 110 EP - 119 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-30100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mielke, Johannes A1 - Rades, Steffi A1 - Ortel, Erik A1 - Salge, T. A1 - Hodoroaba, Vasile-Dan T1 - Improved spatial resolution of EDX/SEM for the elemental analysis of nanoparticles N2 - The interest in nanoparticles remains at a high level in fundamental research since many years and increasingly, nanoparticles are incorporated into consumer products to enhance their performance. Consequently, the accurate and rapid characterization of nanoparticles is more and more demanded. Electron microscopy (SEM, TSEM and TEM) is one of the few techniques which are able to image individual nanoparticles. It was demonstrated recently that the transmission electron microscopy at a SEM can successfully be applied as a standard method to characterize accurately the size (distribution) and shape of nanoparticles down to less than 10 nm. PY - 2015 DO - https://doi.org/10.1017/S1431927615009344 SN - 1431-9276 SN - 1435-8115 VL - 21 IS - Suppl. 3 SP - Paper 0855, 1713 EP - 1714 PB - Cambridge University Press CY - New York, NY AN - OPUS4-34923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Salge, T. A1 - Terborg, R. A1 - Ball, A. D. A1 - Broad, G.R. A1 - Kearsley, A.T. A1 - Jones, C.G. A1 - Smith, C. A1 - Rades, Steffi A1 - Hodoroaba, Vasile-Dan ED - Hozak, P. T1 - Advanced SEM/EDS analysis using an annular silicon drift detector (SDD): Applications in nano, life, earth and planetary sciences below micrometer scale N2 - Analysis of fine-scale structures requires low accelerating voltages. Consequently, only low to intermediate energy X-ray lines with many peak overlaps can be evaluated which requires deconvolution. Examination of nano-scale structures also requires low probe currents which would give low X-ray count rates with traditional EDX detectors. The additional time required to acquire sufficient data for deconvolution risks altering the specimen as a result of beam-sample interaction or sample contamination. The BRUKER XFIash 5060F SDD has allowed us to overcome these limitations and offers additional benefits as we demonstrate here. T2 - IMC 2014 - 18th International microscopy congress CY - Prague, Czech Republic DA - 07.09.2014 PY - 2014 SN - 978-80-260-6720-7 SP - IT-5-P-1842, 1-2 AN - OPUS4-31944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Oswald, F. A1 - Narbey, S. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Analytical approach for characterization of morphology and chemistry of a CH3NH3PbI3/TiO2 solar cell layered system N2 - Manufacturing of new perovskite layered solar cells with constant high light conversion Efficiency over time may be hampered by the loss of efficiency caused by structural and/or chemical alterations of the complex layered system. SEM/EDX combined with XPS were chosen as an appropriate methodical approach to characterize perovskite laboratory cells in depth and at surface, before and after light exposure. The layered perovskite system investigated here is based on glass covered with fluorine doped tin oxide, followed by thin films of TiO2, ZrO2, and a thick monolithic carbon. TiO2 film is subdivided into a dense layer covered by porous one constituted of nanoparticles of truncated bipyramidal shape. This layered system serves as the matrix for the perovskite. EDX spectral maps on cross sections of specimen have shown that Pb and I are distributed homogeneously throughout the porous layers C, ZrO2, and TiO2. SEM/EDX data show that 20 weeks of ambient daylight did not change significantly the in‐depth distribution of the elemental composition of Pb and I throughout the entire 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 compositional and chemical altering began in the near‐surface region of the outermost ~10 nm after 2 months of illumination which was observed with XPS. T2 - ECASIA 2017 CY - Montpellier, France DA - 24.09.2017 KW - Solar Cell KW - SEM KW - EDX KW - XPS KW - layered system PY - 2018 DO - https://doi.org/10.1002/sia.6410 SN - 0142-2421 SN - 1096-9918 VL - 50 IS - 11 SP - 1234 EP - 1238 PB - John Wiley & Sons, Ltd. AN - OPUS4-46394 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Holzweber, Markus A1 - Pellegrino, F. A1 - Martra, G. A1 - Hodoroaba, Vasile-Dan T1 - Analysis of fluorine traces in TiO2 nanoplatelets by SEM/EDX, AES and TOF-SIMS N2 - Hydrothermal synthesis of anatase TiO2 nanosheets with a high fraction of exposed {001} facets and related high photocatalytic activity - as an alternative to bipyramidal anatase TiO2 nanoparticles mainly exposing the {101} facets. The scope of the material preparation work is the thermal reduction of residual fluorides from HF (capping agent) induced during the synthesis of TiO2 nanosheets by calcination at 873K. The analytical task consists of detection and localization of fluorine present at the surface and/or in the bulk of TiO2 nanosheets before and after calcination by SEM/EDX, Auger electron spectroscopy and ToF-SIMS. KW - Fluorine KW - SEM/EDX KW - TiO2 nanoplatelets KW - Auger electron spectroscopy KW - TOF-SIMS PY - 2017 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/analysis-of-fluorine-traces-in-tio2-nanoplatelets-by-semedx-aes-and-tofsims/91EA2C0666B7927FCA57D2AD114910F6 DO - https://doi.org/10.1017/S1431927617010200 SN - 1435-8115 SN - 1431-9276 VL - 23 IS - S1 (July) SP - 1908 EP - 1909 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-42455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rades, Steffi T1 - Morphological and elemental characterization of engineered nanoparticles by a multi-method approach: T-SEM, EDS and AES T2 - 8th Conference on Environmental Effects of Nanoparticles and Nanomaterials CY - Aix-en-Provence, France DA - 2013-07-03 PY - 2013 AN - OPUS4-29553 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Maaßdorf, A. A1 - Rooch, Heidemarie A1 - Österle, Werner A1 - Malcher, M. A1 - Schmidt, M. A1 - Kollmer, F. A1 - Paul, D. A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Unger, Wolfgang T1 - Lateral resolution of nanoscaled images delivered by surface-analytical instruments: application of the BAM-L200 certified reference material and related ISO standards N2 - The certified reference material BAM-L200, a nanoscale stripe pattern for length calibration and specification of lateral resolution, is described. BAM-L200 is prepared from a cross-sectioned epitaxially grown layer stack of AlxGa1–xAs and InxGa1–xAs on a GaAs substrate. The surface of BAM-L200 provides a flat pattern with stripe widths ranging down to 1 nm. Calibration distances, grating periods and stripe widths have been certified by TEM with traceability to the length unit. The combination of gratings, isolated narrow stripes and sharp edges of wide stripes offers plenty of options for the determination of lateral resolution, sharpness and calibration of length scale at selected settings of imaging surface-analytical instruments. The feasibility of the reference material for an analysis of the lateral resolution is demonstrated in detail by evaluation of ToF-SIMS, AES and EDX images. Other applications developed in the community are summarized, too. BAM-L200 fully supports the implementation of the revised International Standard ISO 18516 (in preparation) which is based on knowledge outlined in the Technical Report ISO/TR 19319:2013. KW - AES KW - BAM-L200 KW - CRM KW - EDX KW - Imaging KW - Lateral resolution KW - Sharpness KW - Standardisation KW - STXM KW - ToF-SIMS KW - XPEEM KW - XPS KW - Certified reference material KW - Imaging surface analysis PY - 2015 DO - https://doi.org/10.1007/s00216-014-8135-7 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 11 SP - 3211 EP - 3217 PB - Springer CY - Berlin AN - OPUS4-33033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mino, L. A1 - Pellegrino, F. A1 - Rades, Steffi A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Spotto, G. A1 - Maurino, V. A1 - Martra, G. T1 - Beyond shape engineering of TiO2 nanoparticles: Post-synthesis treatment dependence of surface hydration, hydroxylation, Lewis acidity and photocatalytic activity of TiO2 anatase nanoparticles with dominant {001} or {101} facets N2 - TiO2 anatase nanoparticles are among the relevant players in the field of light-responsive semiconductor nanomaterials used to face environmental and energy issues. In particular, shape-engineered TiO2 anatase nanosheets with dominant {001} basal facets gained momentum because of the possibility to exploit different and/or improved functional behaviors with respect to usual bipyramidal TiO2 anatase nanoparticles, mainly exposing {101} facets. Nevertheless, such behavior depends in a significant extent on the physicochemical features of surfaces exposed by nanosheets. They can vary in dependence on the presence or removal degree of capping agents, namely, fluorides, used for shape-engineering, and experimental investigations in this respect are still a few. Here we report on the evolution of interfacial/ surface features of TiO2 anatase nanosheets with dominant {001} facets from pristine nanoparticles fluorinated both in the bulk and at their surface to nanoparticles with F− free surfaces by treatment in a basic solution and to totally F− free nanoparticles by calcination at 873 K. The nanoparticles fluorine content and its subsequent evolution is determined by complementary techniques (ion chromatography, TOF-SIMS, XPS, AES, SEM-EDX), probing different depths. In parallel, the evolution of the electronic properties and the Ti valence state is monitored by UV−vis spectroscopy and XPS. The calcination treatment results in {001} facets poorly hydroxylated, hydrated, and hydrophilic, which appear as surface features consequent to the expected (1 × 4) reconstruction. Moreover, IR spectroscopy of CO adsorbed as probe molecule indicates that the Lewis acidity of Ti4+ sites exposed on (1 × 4) reconstructed {001} facets of calcined TiO2 nanosheets is weaker than that of cationic centers on {101} facets of bipyramidal TiO2 anatase nanoparticles. The samples have also been tested in phenol photodegradation highlighting that differences in surface hydration, hydroxylation, and Lewis acidity between TiO2 nanoparticles with nanosheet (freed by F− by calcination at 873 K) and bipyramidal shape have a strong impact on the photocatalytic activity that is found to be quite limited for the nanoparticles mainly exposing (1 × 4) reconstructed {001} facets. KW - Nanoparticles KW - TiO2 KW - F- doping KW - Shape-controlled nanoparticles KW - Nanosheets PY - 2018 DO - https://doi.org/10.1021/acsanm.8b01477 SN - 2574-0970 VL - 1 IS - 9 SP - 5355 EP - 5365 PB - ACS Publications CY - Washington, DC, U.S.A. AN - OPUS4-46157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rades, Steffi 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 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 - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Salge, T. A1 - Mielke, Johannes A1 - Ortel, Erik A1 - Schmidt, R. T1 - Characterisation of nanoparticles by means of high-resolution SEM/EDS in transmission mode N2 - Advances in scanning electron microscopy (SEM) enable the high-resolution imaging of single nanoparticles (NPs) with sizes well below 10 nm. The SEM analysis in transmission mode (T-SEM) of NPs on thin film supports has many benefits when compared to the analysis of NPs on bulk substrates. The enhanced material (mass – thickness) contrast of the T-SEM imaging mode is well suited for in-depth and, particularly valuable, to very accurate, traceable, lateral dimensional measurements of NPs. Compared to samples prepared on bulk substrates, T-SEM with energy dispersive X-ray spectroscopy (EDS) achieves a drastically improved spatial resolution of the emitted X-rays. The poor signal-to-noise ratio of the X-ray spectra emitted by a single nanoparticle (NP) can be improved by the use of high-sensitivity (high collection solid angle) silicon drift (SDD), energy-dispersive X-ray spectrometers (EDS). The EDS spectral imaging of a single NP with a spatial resolution below 10 nm has become possible. This is demonstrated by means of various examples of nanostructures. Advanced data processing of T-SEM/EDS results sets the stage for the automated classification of NPs by feature analysis. This method combines the detection of morphological structures of interest by image processing of T-SEM micrographs with the chemical classification by EDS. T2 - European Microbeam Analysis Society’s 14th European Workshop on Modern Developments and Applications in Microbeam Analysis (EMAS 2015) CY - Portorož, Slovenia DA - 03.05.2015 KW - High-resolution KW - SEM KW - T-SEM KW - EDX KW - Nanoparticles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355628 UR - http://iopscience.iop.org/article/10.1088/1757-899X/109/1/012006 DO - https://doi.org/10.1088/1757-899X/109/1/012006 SN - 1757-899X VL - 109 SP - 012006-1 EP - 012006-12 PB - IOP Publishing Ltd CY - Bristol, UK AN - OPUS4-35562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR 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, G. A1 - Martra, G. T1 - Organic surface modification and analysis of titania nanoparticles for self‐assembly in multiple layers N2 - The characteristics of TiO2 coatings can greatly influence their final performance in large‐scale applications. In the present study, self‐assembly of TiO2 nanoparticles (NPs) in multiple layers was selected as a deposition procedure on various substrates. For this, the main prerequisite constitutes the surface modification of both NPs and substrate with, for example, silane coupling agents. A set of functionalized TiO2 NPs has been produced by reaction with either (3‐aminopropyl)triethoxysilane (APTES) or (3‐aminopropyl)phosphonic acid (APPA) to functionalize the NP surface with free amino‐groups. Then, the complementary functionalized NP set can be obtained from an aliquot of the first one, through the conversion of free surface amino groups to aldehydes by reaction with glutaraldehyde (GA). Several types of TiO2 NPs differing in size, shape, and specific surface area have been functionalized. Fourier‐transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), SEM/ energy‐dispersive X‐ray spectroscopy (EDS), XPS, Auger electron spectroscopy (AES), and Time‐of‐Flight (ToF)‐SIMS analyses have been carried out to evaluate the degree of functionalization, all the analytical methods employed demonstrating successful functionalization of TiO2 NP surface with APTES or APPA and GA. KW - TiO2 KW - Nanoparticles KW - Surface functionalization KW - Layer-by-layer deposition KW - Surface chemical analysis PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508601 DO - https://doi.org/10.1002/sia.6842 SN - 1096-9918 VL - 52 IS - 12 SP - 829 EP - 834 PB - John Wiley & Sons Ltd AN - OPUS4-50860 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Salge, T. A1 - Mielke, Johannes A1 - Ortel, Erik A1 - Schmidt, R. T1 - Characterisation of nanoparticles by means of high-resolution SEM/EDS N2 - Advances in scanning electron microscopy (SEM) enable the high-resolution imaging of single nanoparticles (NPs) with sizes well below 10 nm. The SEM analysis in transmission mode (T-SEM) of NPs on thin film supports has many benefits when compared to the analysis of NPs on bulk substrates. The enhanced material (mass - thickness) contrast of the T-SEM imaging mode is well suited for in-depth and, particularly valuable, to very accurate, traceable, lateral dimensional measurements of NPs. Compared to samples prepared on bulk substrates, T-SEM with energy dispersive X-ray spectroscopy (EDS) achieves a drastically improved spatial resolution of the emitted X-rays. The poor signal-to-noise ratio of the X-ray spectra emitted by a single nanoparticle (NP) can be improved by the use of high-sensitivity (high collection solid angle) silicon drift (SDD), energy-dispersive X-ray spectrometers (EDS). The EDS spectral imaging of a single NP with a spatial resolution below 10 nm has become possible. This is demonstrated by means of various examples of nanostructures. Advanced data processing of T-SEM/EDS results sets the stage for the automated classification of NPs by feature analysis. This method combines the detection of morphological structures of interest by image processing of T-SEM micrographs with the chemical classification by EDS. T2 - EMAS 2015 - 14th European workshop on modern developments and applications in microbeam analysis CY - Portoroz, Slovenia DA - 03.05.2015 KW - SEM KW - T-SEM KW - EDX KW - Nanoparticles KW - High-resolution PY - 2015 SN - 978-90-8227-691-6 DO - https://doi.org/10.1088/1757-899X/109/1/012006 SP - NUR code:972 - Materials Science, 187-199 AN - OPUS4-33258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Donėlienė, J. A1 - Rudzikas, M. A1 - Rades, Steffi A1 - Dörfel, Ilona A1 - Peplinski, Burkhard A1 - Sahre, Mario A1 - Pellegrino, F. A1 - Maurino, V. A1 - Ulbikas, J. A1 - Galdikas, A. A1 - Hodoroaba, Vasile-Dan T1 - Electron Microscopy and X-Ray Diffraction Analysis of Titanium Oxide Nanoparticles Synthesized by Pulsed Laser Ablation in Liquid N2 - A femto-second pulsed laser ablation in liquid (PLAL) procedure for the generation of titanium oxide nanoparticles (NP) is reported with the purpose of understanding morphology and structure of the newly generated NPs. Ablation duration was varied for optimization of NP generation processes between 10 and 90 min. Surface morphology of NPs as well as their size and shape (distribution) were analysed by various complementary electron microscopy techniques, i.e. SEM, TSEM and TEM. The crystalline structure of titanium oxide particles was investigated by XRD(two instruments operated in different geometries) and HR-TEM. Concentration of generated titanium oxide NPs in liquid was analysed by ICP-MS. A mix of crystalline (mainly anatase), partly crystalline and amorphous spherical titanium oxide NPs can be reported having a mean size between 10 and 20 nm, which is rather independent of the laser ablation (LA) duration. A second component consisting of irregularly shaped, but crystalline titanium oxide nanostructures is co-generated in the LA water, with more pronounced occurrence at longer LA times. The provenance of this component is assigned to those spherical particles generated in suspension and passing through the converging laser beam, being hence subject to secondary irradiation effects, e. g. fragmentation. KW - Laser ablation in liquid KW - Nanoparticles KW - Titanium oxide KW - Particle morphology PY - 2018 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/electron-microscopy-and-xray-diffraction-analysis-of-titanium-oxide-nanoparticles-synthesized-by-pulsed-laser-ablation-in-liquid/AE368446FAC70E08C514F9AEABFD131B DO - https://doi.org/10.1017/S1431927618009030 VL - 24 IS - S1 (August) SP - 1710 EP - 1711 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-45949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Oswald, F. A1 - Narbey, S. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan 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. 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. 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. 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. KW - Pervskite solar cells KW - TiO2 KW - Porous layer KW - SEM/EDX KW - XPS PY - 2017 UR - https://www.cambridge.org/core/services/aop-cambridge-core/content/view/0E9E937542BC8B5535900B53B7F667E9/S1431927617010558a.pdf/complementary_methodical_approach_for_the_analysis_of_a_perovskite_solar_cell_layered_system.pdf DO - https://doi.org/10.1017/S1431927617010558 VL - 23 IS - S1 (July) SP - 1978 EP - 1979 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-41925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -