TY - JOUR A1 - Guo, Y. A1 - Lippitz, Andreas A1 - Saftien, P. A1 - Unger, Wolfgang A1 - Kemnitz, E. T1 - Tuning the surface properties of novel ternary iron(III) fluoride-based catalysts using the template effect of the matrix N2 - Sol–gel prepared ternary FeF3–MgF2 materials have become promising heterogeneous catalysts due to their porosity and surface Lewis/Brønsted acidity (bi-acidity). Despite the good catalytic performance, nanoscopic characterisations of this type of material are still missing and the key factors controlling the surface properties have not yet been identified, impeding both a better understanding and further development of ternary fluoride catalysts. In this study, we characterised the interaction between the bi-acidic component (FeF3) and the matrix (MgF2) on the nano-scale. For the first time, the formation pathway of FeF3–MgF2 was profiled and the template effect of MgF2 during the synthesis process was discovered. Based on these new insights two novel materials, FeF3–CaF2 and FeF3–SrF2, were established, revealing that with decreasing the atomic numbers (from Sr to Mg), the ternary fluorides exhibited increasing surface acidity and surface area but decreasing pore size. These systematic changes gave rise to a panel of catalysts with tuneable surface and bulk properties either by changing the matrix alkaline earth metal fluoride or by adjusting their ratios to Fe or both. The template effect of the alkaline earth metal fluoride matrix was identified as the most probable key factor determining the surface properties and further influencing the catalytic performance in ternary fluoride based catalysts, and paves the way to targeted design of next-generation catalysts with tunable properties. KW - Catalysis KW - Surface analysis KW - XPS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-327410 DO - https://doi.org/10.1039/c4dt03229b SN - 1477-9226 SN - 1477-9234 SN - 1364-5447 VL - 44 IS - 11 SP - 5076 EP - 5085 PB - RSC CY - Cambridge AN - OPUS4-32741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwarz, F. A1 - Heinrich, Thomas A1 - Lippitz, Andreas A1 - Unger, Wolfgang A1 - Schalley, C. T1 - A photoswitchable rotaxane operating in monolayers on solid support N2 - A novel photoswitchable rotaxane was synthesised and its switching behaviour in solution was analysed with NMR and UV-Vis. A monolayer of rotaxanes was deposited on glass surfaces and the on-surface photoswitching was investigated. Angle-resolved NEXAFS spectra revealed a preferential orientation that reversibly changes upon switching. KW - XPS KW - NEXAFS KW - Photoswitchable rotaxane KW - Self assembly PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-386814 DO - https://doi.org/10.1039/c6cc08586e SN - 0022-4936 SN - 1364-548X SN - 0009-241x SN - 1359-7345 VL - 52 IS - 100 SP - 14458 EP - 14461 PB - Royal Society of Chemistry (RSC) AN - OPUS4-38681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang T1 - NEXAFS and XPS analysis of functionalized graphene surfaces for bio applications N2 - Graphene prepared from Graphene oxide (GO) is used as a platform for functional 2D nanomaterials with diverse applications ranging from bios ensors to antimicrobial surfaces. C and N K-edge NEXAFS and XPS spectroscopies at BESSY’s HE-SGM beamline have been used to prove and control covalent functionalization of graphenic materials at ambient conditions for the synthesis of functional 2D-surfaces. T2 - 8th Jouint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 7.12.2016 KW - XPS KW - NEXAFS KW - Graphene PY - 2016 AN - OPUS4-38683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit T1 - MetVBadBugs - XRF and NAP-XPS characterization of drug uptake in multi-resistant bacteria N2 - Multi-resistant bacteria embedded in infectious biofilms are one of the largest future threats in human healthcare. The mechanism of drug uptake and the origin of resistancy is quantitatively not well characterized and understood. Modern X-ray and synchrotron excited spectroscopic methods like XRF and NAP-XPS under ambient pressure conditions and liquid media will add new insights into this field. T2 - 8th Jouint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 7.12.2016 KW - XPS KW - XRF KW - Biofilm PY - 2016 AN - OPUS4-38684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lange, Nele T1 - Nuclease activity of copper(II)phenanthroline complexes immobilized on silicon nitride films N2 - Copper(II)phenanthroline complexes intercalate into DNA and induce DNA cleavage. Here, we investigate the nuclease activity of copper(II)phenanthroline complexes on Silicon nitride films. 1,10-phenanthroline-5-carboxylic acid is immobilized at Si-NHx bonds via amide coupling followed by the formation of copper(II)phenanthroline complexes. XPS and NEXAFS were carried out at the HE-SGM beamline. T2 - 8th Jouint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 7.12.2016 KW - XPS KW - NEXAFS KW - Copper(II) - phenanthroline - complexe filmss PY - 2016 AN - OPUS4-38685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Beiranvand, Z. A1 - Kakanejadifard, A. A1 - Donskyi, Ievgen A1 - Faghani, A. A1 - Tu, Z. A1 - Lippitz, Andreas A1 - Sasanpour, P. A1 - Maschietto, F. A1 - Paulus, B. A1 - Haag, R. A1 - Adeli, M. T1 - Functionalization of fullerene at room temperature: toward new carbon vectors with improved physicochemical properties N2 - In this work, fullerene has been functionalized with cyanuric Chloride at room temperature by a nitrene mediated [2 + 1] cycloaddition reaction. The adduct after functionalization is inherently in the form of azafulleroid and shows broad UV absorption in the wavelength range of 200–800 nm, as well as photothermal conversion and fluorescence with a high quantum yield. KW - Functionalization of fullerenes KW - XPS KW - NEXAFS PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-387076 DO - https://doi.org/10.1039/c6ra23419d SN - 2046-2069 VL - 6 IS - 114 SP - 112771 EP - 112775 PB - Royal Society of Chemistry (RSC) AN - OPUS4-38707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ehlert, Christopher A1 - Kröner, D. A1 - Saalfrank, P. T1 - A combined quantum chemical/molecular dynamics study of X-rayphotoelectron spectra of polyvinyl alcohol using oligomer models N2 - X-ray photoelectron spectroscopy (XPS) is a powerful tool for probing the local chemical environment ofatoms near surfaces. When applied to soft matter, such as polymers, XPS spectra are frequently shifted andbroadened due to thermal atom motion and by interchain interactions. We present a combined quantummechanical QM/molecular dynamics (MD) simulation of X-ray photoelectron spectra of polyvinyl alcohol(PVA) using oligomer models in order to account for and quantify these effects on the XPS (C1s) signal. Inour study, molecular dynamics at finite temperature were performed with a classical forcefield and by abinitio MD (AIMD) using the Car–Parrinello method. Snapshots along the trajectories represent possibleconformers and/or neighbouring environments, with different C1s ionization potentials for individualC atoms leading to broadened XPS peaks. The latter are determined by Δ-Kohn Sham calculations. Wealso examine the experimental practice of gauging XPS (C1s) signals of alkylic C-atoms in C-containingpolymers to the C1s signal of polyethylene. We find that (i) the experimental XPS (C1s) spectra of PVA (position and width) can be roughly repre-sented by single-strand models, (ii) interchain interactions lead to red-shifts of the XPS peaks by about0.6 eV, and (iii) AIMD simulations match the findings from classical MD semi-quantitatively. Further, (iv)the gauging procedure of XPS (C1s) signals to the values of PE, introduces errors of about 0.5 eV. KW - XPS KW - Quantummechanical molecular dynamics simulation KW - Polyvinyl alcohol PY - 2015 DO - https://doi.org/10.1016/j.elspec.2014.12.007 SN - 0368-2048 VL - 199 SP - 38 EP - 45 PB - Elsevier B.V. AN - OPUS4-39290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Unger, Wolfgang T1 - Measuring organic layers N2 - Many innovative products - from touchscreens to solar panels to pharmaceuticals – utilise multiple organic layers to create complex functionality. New techniques have been developed to remove and measure layers individually enabling improved product development and assisting with quality assurance. However, manufacturers cannot be certain of the depth of layer being removed and new reference materials for these techniques are needed to increase uptake, and remove a major barrier to innovation. KW - Organic layers KW - XPS KW - SIMS PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-388656 UR - http://www.euramet.org/metrology-for-societys-challenges/metrology-for-industry/impact-case-studies-emrp-industry-theme/ SP - 1 EP - 2 CY - Teddington AN - OPUS4-38865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Anja T1 - WP3 (A 3.3.5 / 3.3.6) electron spectroscopy of core/shell nanoparticles N2 - The presentation summarizes the progress of activity 3.3.5 and 3.3.6 of the Innanopart project. These activities focus on the investigation of different core@shell nanoparticles using synchrotron-radiation-XPS and AES. T2 - Innanopart 18 Months Meeting (EMPIR) CY - Vienna, Austria DA - 31.10.2016 KW - XPS KW - Synchrotron KW - Depth-Profiling KW - AES KW - Core@Shell Nanoparticles PY - 2016 N1 - Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. AN - OPUS4-38792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Anja T1 - Quantitative chemichal depth-profiling by synchrotron-radiation-XPS N2 - Synchrotron-radiation enables the adjustment of the XPS information depth and, thus, the visualization of depth profiles of the elemental composition within the first 10 nm of a surface. This project deals with the analysis of core-shell nanoparticles. It constitutes first steps towards a valid methodology for studying the surface chemistry of nanoparticles in a quantitative and accurate manner. T2 - Eighth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 07.12.2016 KW - XPS KW - Synchrotron KW - Depth-profiling KW - Core@Shell Nanoparticles PY - 2016 N1 - Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. AN - OPUS4-38782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -