TY - CONF A1 - Beckmann, Jörg A1 - Richter, Heike A1 - Zscherpel, Uwe A1 - Ewert, Uwe A1 - Weinzierl, J. A1 - Schmidt, L.-P. A1 - Rutz, F. A1 - Koch, M. A1 - Richter, H. A1 - Hübers, H.-W. T1 - Imaging Capability of Terahertz and Millimeter-Wave Instrumentations for NDT of Polymer Materials T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - Time domain spectroscopy KW - Air coupled ultrasound KW - Pulsed THz radiation system KW - Pulse compression KW - THz imaging PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 9(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-13875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meißner, T. A1 - Richter, W. A1 - Stephan, H. A1 - Zänker, H. A1 - Kraus, Werner T1 - Darstellung und Charakterisierung von Nanopartikeln auf der Basis von [Ti2W10PO40]7- und Chitosan KW - Polyoxometallate KW - Nanopartikel KW - Clusterverbindung PY - 2005 DO - https://doi.org/10.1002/cite.200590281 SN - 0009-286X SN - 1522-2640 VL - 77 IS - 8 SP - 1227 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-11080 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meißner, T. A1 - Bergmann, R. A1 - Oswald, J. A1 - Rode, K. A1 - Stephan, H. A1 - Richter, W. A1 - Zänker, H. A1 - Kraus, Werner A1 - Emmerling, Franziska A1 - Reck, Günter T1 - Chitosan-encapsulated Keggin anion [Ti2W10PO40]7-.Synthesis, characterization and cellular uptake studies N2 - The Keggin type polyoxotungstate [Ti2W10PO40]7- forms stable associates with the biopolymer chitosan in the nanometer size range. The cluster compound crystallizes from aqueous solution as K4H3[Ti2W10PO40] · 15H2O having a tetragonal structure. Both, the cluster compound and the chitosan/[Ti2W10PO40] associates show a high hydrolytic stability at pH 7.4. The associates formed between the cluster anion [Ti2W10PO40]7- with the polyaminosaccharide chitosan have been characterized by photon correlation spectroscopy, scanning electron microscopy, filtration, centrifugation and zeta potential measurements. The size of the associates formed is in the range of ca. 5×101 to 5×102 nm. These particles have a defined stoichiometry with 5–6 cluster anions bound per molecule chitosan. The isoelectric point determined by zeta potential measurements was found for a cluster anion to chitosan molar ratio of 5.5, indicating the charge neutralization between protonated chitosan and [Ti2W10PO40]7- anions. Cellular uptake studies with [Ti2W10PO40]7- using tumor cell lines FaDu (human squamous carcinoma) and HT-29 (human adenocarcinoma) showed that the tungsten amount inside the cells is remarkably enhanced in the presence of chitosan. KW - Cluster compound KW - Keggin structure KW - Bipolymer KW - Chitosan PY - 2006 DO - https://doi.org/10.1007/s11243-006-0035-z SN - 0340-4285 SN - 1572-901X VL - 31 IS - 5 SP - 603 EP - 610 PB - Springer CY - Dordrecht AN - OPUS4-12568 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ressel, P. A1 - Hao, P.H. A1 - Park, M.H. A1 - Yang, Z. C. A1 - Wang, L.C. A1 - Österle, Werner A1 - Kurpas, P. A1 - Richter, E. A1 - Kuphal, E. A1 - Hartnagel, H.L. T1 - Pd/Sb(Zn) and Pd/Ge(Zn) Ohmic Contacts on p-Type Indium Gallium Arsenide: The Employment of the Solid Phase Regrowth Principle to Achieve Optimum Electrical and Metallurgical Properties N2 - The development of two metallizations based on the solid-phase regrowth principle is presented, namely Pd/Sb(Zn) and Pd/Ge(Zn) on moderately doped In0.53Ga0.47As (p=4×1018 cm-3). Contact resistivities of 2–3×10-7 and 6–7×10-7 ?cm2, respectively, have been achieved, where both systems exhibit an effective contact reaction depth of zero and a Zn diffusion depth below 50 nm. Exhibiting resistivities equivalent to the lowest values of Au-based systems in this doping range, especially Pd/Sb(Zn) contacts are superior to them concerning metallurgical stability and contact penetration. Both metallizations have been successfully applied for contacting the base layer of InP/In0.53Ga0.47As heterojunction bipolar transistors. KW - Ohmic contacts KW - Indium gallium arsenide KW - InP/InGaAs heterojunction bipolar transistor KW - Solid-phase regrowth KW - Pd/Ge contacts KW - Pd/Sb contacts KW - Backside secondary ion mass spectrometry (SIMS) PY - 2000 DO - https://doi.org/10.1007/s11664-000-0189-y SN - 0361-5235 SN - 1543-186X VL - 29 IS - 7 SP - 964 EP - 972 PB - TMS CY - Warrendale, Pa. AN - OPUS4-7642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, M. A1 - Schultz, C. A1 - Bonse, Jörn A1 - Pahl, H.-U. A1 - Endert, H. A1 - Rau, B. A1 - Schlatmann, R. A1 - Quaschning, V. A1 - Stegemann, B. A1 - Fink, F. T1 - Laser-ablation behavior of thin-film materials used in silicon and CIGSe based solar cells N2 - Structuring of thin-film photovoltaic modules requires basic knowledge of the laser – thin-film interaction in order to adapt the accessible laser parameters, like wavelength, power, repetition rate and scribing speed whilst taking into account the specific material properties of the layer. We have studied the nanosecond laserablation behavior of corresponding layers (i) of silicon based thin-film solar cells with a-Si/µc-Si tandem absorber type and (ii) of back contact and absorber layer of CIGSe solar cells. The respective ablation threshold fluences were determined as integrative parameters describing the specific laser – material interaction. For the threshold determination we used two different methods and developed a new analytical approach taking into account scribing through the glass substrate as it is preferred for most structuring processes. This was done by analyzing the thin film ablation results by means of optical microscopy, profilometry, scanning electron microscopy (SEM). Moreover, we determined the incubation coefficient of the regarded material layers which allows us to predict quantitatively the influence of the spot overlap on the scribing threshold. T2 - 26th European photovoltaic solar energy conference and exhibition CY - Hamburg, Germany DA - 05.09.011 KW - Laser processing KW - Ablation KW - Incubation KW - a-Si/my-Si KW - CIGS PY - 2011 SN - 3-936338-27-2 DO - https://doi.org/10.4229/26thEUPVSEC2011-3DV.2.8 SP - 2943 EP - 2946 AN - OPUS4-24997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schultz, C. A1 - Schüle, M. A1 - Richter, M. A1 - Pahl, H.-U. A1 - Endert, H. A1 - Bonse, Jörn A1 - Dirnstorfer, I. A1 - Rau, B. A1 - Schlatmann, R. A1 - Quaschning, V. A1 - Fink, F. A1 - Stegemann, B. T1 - P1, P2 and P3 structuring of CIGSe solar cells with a single laser wavelength N2 - Manufacturing of CIGSe thin film solar modules involves typically one laser structuring step (P1) and two mechanical structuring steps (P2 and P3) for serial interconnection. In our approach, complete laser structuring is successfully demonstrated by application of short nanosecond laser pulses (<10 ns) with a single, visible wavelength of 532 nm. The P1 and the P3 trenches are scribed by induced and direct ablation, respectively. For the P2 scribe, the thermal input of the ns laser pulses is used to transform the CIGSe absorber layer locally into a highly conductive compound to provide proper electrical interconnection. These findings promise further simplification and flexibility to thin film solar cell production. T2 - 26th European photovoltaic solar energy conference and exhibition CY - Hamburg, Germany DA - 05.09.2011 KW - Laser processing KW - Nanosecond pulses KW - Ablation KW - Cu(InGa)Se2 KW - Electrical properties PY - 2011 SN - 3-936338-27-2 DO - https://doi.org/10.4229/26thEUPVSEC2011-3AV.1.35 SP - 2540 EP - 2543 AN - OPUS4-24998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stegemann, B. A1 - Schultz, C. A1 - Schüle, M. A1 - Richter, M. A1 - Pahl, H.-U. A1 - Endert, H. A1 - Bonse, Jörn A1 - Rau, B. A1 - Schlatmann, R. A1 - Quaschning, V. A1 - Fink, F. ED - Luschtinetz, T. ED - Lehmann, J. T1 - Neuartige Laserstrukturierung von CIGSe-Dünnschicht-Solarzellen N2 - Ein wesentlicher Vorteil der Dünnschichtphotovoltaik gegenüber der waferbasierten Photovoltaik liegt in der monolithischen Serienverschaltung. Bei der Herstellung von Chalkopyrit(CIGSe) -Dünnschicht-Solarmodulen erfolgen dafür typischerweise ein Laser-Strukturierungsschritt (P1) und zwei mechanische Strukturierungsschritte (P2, P3). In diesem Beitrag wird gezeigt, dass die Strukturierung von CIGSe-Solarmodulen vollständig mit kurzen Laserpulsen (<10 ns Pulsdauer) und einer einzigen Wellenlänge (532 nm) möglich ist. Der P1- und P3-Schnitt erfolgen durch direkte induzierte Ablation. Für den P2-Schnitt wird gezielt der hohe Wärmeeintrag der ns-Laserpulse genutzt, um die CIGSe- Absorberschicht lokal aufzuschmelzen und strukturell so zu verändern, dass eine elektrisch gut leitende Verbindung zwischen Front- und Rückkontakt entsteht. N2 - A major advantage of thin film photovoltaics over wafer-based photovoltaics is the monolithic series connection. Manufacturing of chalcopyrite (CIGSe) thin film solar modules involves typically one laser structuring step (P1) and two mechanical structuring steps (P2 and P3) for serial interconnection. In our approach, complete laser structuring is successfully demonstrated simply by application of short nanosecond laser pulses (<10 ns) with a single, visible wavelength of 532 nm. The P1 and the P3 trenches are scribed by induced direct ablation. For the P2 scribe, the thermal input of the ns laser pulses is used to transform the CIGSe absorber layer locally into a highly conductive compound to provide proper electrical interconnection between the front and back contact. T2 - 18. Symposium "Nutzung regenerativer Energiequellen und Wasserstofftechnik" / VDI-Tagung "Energieland Mecklenburg-Vorpommern" CY - Stralsund, Germany DA - 03.11.2011 KW - Photovoltaik KW - Dünnschichtsolarzellen KW - Chalkopyrite KW - Laserstrukturierung PY - 2011 SN - 978-3-9813334-4-2 SP - 204 EP - 210 AN - OPUS4-24999 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stegemann, B. A1 - Richter, M. A1 - Schultz, C. A1 - Pahl, H.-U. A1 - Endert, H. A1 - Bonse, Jörn A1 - Rau, B. A1 - Quaschning, V. A1 - Fink, F. T1 - One wavelength fits all N2 - Structuring of Thin-film Solar Cells with a Single Laser Wavelength Structuring of a PV module into a number of cells is necessary to lower the current and to increase the voltage, and is typically accomplished with nanosecond laser pulses of different wavelengths. Duetothe many available laser sources, complex and expensive scribing Setups are necessary. To overcome this a concept for laser structuring of thin-film PV modules using a single wavelength allows prediction ofthe ablation behaviourfor a given laser pulse energy. KW - Thin-film solar cells KW - Nanosecond laser ablation KW - 532 nm wavelength KW - Laser scribing KW - Damage threshold PY - 2011 SN - 1869-8913 VL - 2 IS - 6 SP - 46 EP - 48 PB - Hüthig CY - Heidelberg AN - OPUS4-24158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shaik, A.-A. A1 - Richter, M. A1 - Kricheldorf, H. A1 - Krüger, Ralph-Peter T1 - New polymer syntheses - CIX. Biodegradable, alternating copolyesters of terephthalic acid, aliphatic dicarboxylic acids, and alkane diols N2 - Copolyesters with an alternating sequence of terephthalic acid and aliphatic dicarboxylic acids were prepared with three different methods. First, dicarboxylic acid dichlorides were reacted with bis(2-hydroxyethyl)terephthalate (BHET) in refluxing 1,2-dichlorobenzene. Second, the same monomers were polycondensed at 0-20 °C in the presence of pyridine. Third, dicarboxylic acid dichlorides and silylated BHET were polycondensed in bulk. Only this third method gave satisfactory molecular weights. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry revealed that the copolyesters prepared by the pyridine and silyl methods might have contained considerable fractions of cyclic oligoesters and polyesters despite the absence of transesterification and backbiting processes. The alternating sequences and thermal properties were characterized with 1H NMR spectroscopy and differential scanning calorimetry measurements, respectively. In agreement with the alternating sequence, all copolyesters proved to be crystalline, but the crystallization was extremely slow [slower than that of poly(ethylene terephthalate)]. A second series of alternating copolyesters was prepared by the polycondensation of silylated bis(4-hydroxybut- yl)terephthalate with various aliphatic dicarboxylic acid dichlorides. The resulting copolyesters showed significantly higher rates of crystallization, and the melting temperatures were higher than those of the BHET-based copolyesters. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3371-3382, 2001 KW - Poly(ethylene terephthalate) KW - Poly(butylene terephthalate) KW - Alternating sequence KW - Macrocycles KW - Crystallization KW - Biodegradable polyesters PY - 2001 DO - https://doi.org/10.1002/pola.1320 SN - 0360-6376 SN - 0887-624X VL - 39 IS - 19 SP - 3371 EP - 3382 PB - Wiley CY - Hoboken, NJ AN - OPUS4-2173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Münch, W. A1 - Richter, Manfred A1 - Frühling, H. G. T1 - Die Eignung der Xenon-Lampe als Standardlichtquelle für Strahlungs- und Farbmessungen PY - 1956 SN - 0014-7680 VL - 5 IS - 1 SP - 41 EP - 68 PB - Musterschmidt CY - Göttingen AN - OPUS4-9895 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darlatt, Erik A1 - Traulsen, C.H.-H. A1 - Poppenberg, J. A1 - Richter, S. A1 - Kühn, Julius A1 - Schalley, C.A. A1 - Unger, Wolfgang T1 - Evidence of click and coordination reactions on a self-assembled monolayer by synchrotron radiation based XPS and NEXAFS N2 - An ethynylterpyridine was 'clicked' to an azide-terminated self-assembled monolayer on gold and characterized by synchrotron radiation based surface analysis as NEXAFS and XPS. The detection of azide and terpyridine signatures confirmed a partial click reaction at room temperature. The absence of the azides after reaction at 50 °C indicates an almost complete conversion. For the latter case successful Pd(II) coordination has been proven. The Au–S interface of the SAMs has been characterized by S 1s and S 2p XPS. KW - Synchrotron radiation XPS KW - NEXAFS spectroscopy KW - Surface click chemistry KW - Self-assembled monolayer KW - HAXPES KW - XANES PY - 2012 DO - https://doi.org/10.1016/j.elspec.2012.02.004 SN - 0368-2048 SN - 1873-2526 VL - 185 IS - 3-4 SP - 85 EP - 89 PB - Elsevier CY - Amsterdam AN - OPUS4-25596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poppenberg, J. A1 - Richter, S. A1 - Darlatt, Erik A1 - Traulsen, C.H.-H. A1 - Min, Hyegeun A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Successive coordination of palladium(II)-ions and terpyridine-ligands to a pyridyl-terminated self-assembled monolayer on gold N2 - The deposition of palladium on a novel, reversibly protonatable, pyridyl-terminated self-assembled monolayer on gold substrates has been studied by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS spectroscopy) and time of flight-secondary ion mass spectrometry (ToF-SIMS). For this purpose, 12-(pyridin-4-yl)dodecane-1-thiol, consisting of a surface-active head group, an unfunctionalized hydrocarbon backbone and a terminal pyridyl group, has been synthesized and deposited on gold surfaces. Coordination of Pd(II) ions to the pyridyl group was examined. Furthermore, a reversible protonation/deprotonation cycle has been applied, and the relation between protonation and the amount of complexed palladium was studied. Investigation of the SAM by angle-resolved NEXAFS spectroscopy revealed the aliphatic backbone to be preferentially upright oriented with the aromatic head group being not preferentially oriented. The palladium layer was further coordinated with a CF3-labeled terpyridine ligand in order to prove the accessibility of the Pd(II) ions to further complexation and the platform useful for deposition of further layers toward a multi-layered system. KW - Supramolecular surface chemistry KW - Pyridine terminated monolayer KW - NEXAFS spectroscopy KW - ToF-SIMS KW - Pyridine-metal coordination PY - 2012 DO - https://doi.org/10.1016/j.susc.2011.10.020 SN - 0039-6028 VL - 606 IS - 3-4 SP - 367 EP - 377 PB - Elsevier CY - Amsterdam AN - OPUS4-25282 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darlatt, Erik A1 - Nefedov, A. A1 - Traulsen, C.H.-H. A1 - Poppenberg, J. A1 - Richter, S. A1 - Dietrich, Paul A1 - Lippitz, Andreas A1 - Illgen, René A1 - Kühn, Julius A1 - Schalley, C.A. A1 - Wöll, Ch. A1 - Unger, Wolfgang T1 - Interperetation of experimental N K NEXAFS of azide, 1,2,3-triazole and terpyridyl groups by DFT spectrum simulations N2 - Experimental N K-edge NEXAFS data of surface immobilized azide, 1,2,3-triazole and terpyridyl groups are interpreted with the help of DFT spectrum simulations. Assignments of π* resonances in experimental N K-edge NEXAFS spectra to nitrogen atoms within these functional groups have been made. The azide was immobilized on gold as the head group of a thiol SAM, 1,2,3-triazole was formed on this SAM by click reaction and terpyridyl groups were introduced as substituents of the acetylene used for the click reaction. For azide-terminated molecules, DFT spectrum simulations are found to be useful to find measurement conditions delivering experimental N K-edge NEXAFS data with negligible X-ray damage. The 1,2,3-triazole group is found to be rather stable under X-ray irradiation. KW - N K-edge NEXAFS KW - XANES KW - Surface click chemistry KW - Density functional theory KW - Azide KW - 1,2,3-Triazole PY - 2012 DO - https://doi.org/10.1016/j.elspec.2012.09.008 SN - 0368-2048 SN - 1873-2526 VL - 185 IS - 12 SP - 621 EP - 624 PB - Elsevier CY - Amsterdam AN - OPUS4-27774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beck, H. A1 - Richter, Manfred T1 - Neukonstruktion des Dreifarbenden-Meßgerätes nach Guild-Bechstein PY - 1958 SN - 0014-7680 VL - 7 IS - 4 SP - 141 EP - 152 PB - Musterschmidt CY - Göttingen AN - OPUS4-7816 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poppenberg, J. A1 - Richter, S. A1 - Traulsen, C.H.-H. A1 - Darlatt, Erik A1 - Baytekin, B. A1 - Heinrich, T. A1 - Deutinger, P.M. A1 - Huth, K. A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Programmable multilayers of nanometer-sized macrocycles on solid support and stimuli-controlled on-surface pseudorotaxane formation N2 - Mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes are capable of mechanical motion on the nanoscale and are therefore promising prototypes for molecular machines in recent nanotechnology. However, most of the existing examples are isotropically distributed in solution, which prohibits concerted movement and with it the generation of macroscopic effects. Thus, arranging them in ordered arrays is of huge interest in recent research. We report the deposition of quite densely packed multilayers of tetralactam macrocycles on gold surfaces by metal-coordinated layer-by-layer self-assembly. Linear dichroism effects in angle-resolved NEXAFS spectra indicate a preferential orientation of the macrocycles. The sequence of the metal ions can be programmed by the use of different transition metal ions at each deposition step. Additionally, reversible on-surface pseudorotaxane formation was successfully realized by repeated uptake and release of axle molecules inside the macrocycles cavities. KW - ISO KW - Standard KW - Surface analysis KW - Imaging PY - 2013 DO - https://doi.org/10.1039/c3sc50558h SN - 2041-6520 SN - 2041-6539 VL - 4 SP - 3131 EP - 3139 PB - RSC CY - Cambridge AN - OPUS4-29049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, S. A1 - Poppenberg, J. A1 - Traulsen, C.H.-H. A1 - Darlatt, Erik A1 - Sokolowski, A. A1 - Sattler, D. A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Deposition of ordered layers of tetralactam macrocycles and ether rotaxanes on pyridine-terminated self-assembled monolayers on gold N2 - The deposition of tetralactam macrocycles and the corresponding benzyl ether rotaxanes on gold substrates is investigated for the first time exploiting metallo-supramolecular chemistry. Two pyridine-terminated self-assembled monolayers (SAMs) are developed that are used as well-ordered template layers. The two SAMs differ with respect to the rigidity of the terminal pyridines as shown by angle-resolved near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The template layers are then used for the metal-mediated self-assembly of macrocylces and rotaxanes on solid supports. The SAM with the more rigid terminal pyridine shows a higher coverage with the macrocycles and is therefore preferable. Angle-resolved NEXAFS spectroscopy also shows the deposited supramolecules to be oriented preferentially upright. This order is only achieved for the macrocycles through the deposition on the more rigid SAM template, whereas rotaxanes form oriented layers on both SAMs. Time-of-flight secondary-ion mass spectrometry analysis was used to determine the deposition time required for the self-assembly process. PY - 2012 DO - https://doi.org/10.1021/ja306212m SN - 0002-7863 SN - 1520-5126 VL - 134 IS - 39 SP - 16289 EP - 16297 PB - American Chemical Society CY - Washington, DC AN - OPUS4-26740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Traulsen, C.H.-H. A1 - Darlatt, Erik A1 - Richter, S. A1 - Poppenberg, J. A1 - Hoof, S. A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Intermixed terpyridine-functionalized monolayers on gold: nonlinear relationship between terpyridyl density and metal ion coordination properties N2 - Aiming at the functionalization of surfaces with terpyridine anchors for the coordinative deposition of additional layers, mixed self-assembled monolayers (SAMs) were prepared from binary solutions of 12-(2,2':6',2''-terpyridine-4'-yl)dodecane-1-thiol (TDT) and 1-decanethiol (DT). The SAMs and the order of the constituting molecules were analyzed by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS), and time-of-flight-secondary ion mass spectrometry (ToF-SIMS). The composition of the (TDT/DT)-SAMs and with it the surface density of terpyridyl groups correlates linearly with the relative concentrations of the two compounds in the solution used for depositing them. In marked contrast, the amount of terpyridine-coordinated PdII ions significantly deviates from this trend with an optimum at a 1:3 ratio of TDT/DT. This indicates a major fraction of the terpyridines in TDT-rich SAMs not to be accessible for PdII ion coordination. In agreement, NEXAFS spectroscopy reveals the alkyl backbones in TDT-rich SAMs not to be ordered, while they are preferentially upright oriented in the optimal 1:3-(TDT/DT)-SAMs. We interpret this in terms of terpyridine backfolding in TDT-rich SAMs, while they are located in accessible positions on top of the SAM in the 1:3-(TDT/DT)-SAM. While the alkyl backbones in the 1:3-(TDT/DT)-SAM are ordered, NEXAFS spectroscopy shows the terpyridyl groups not to have a preferential orientation in this SAM and thus retain enough flexibility to adjust to molecules that are deposited on top of the mixed SAM. In conclusion, the novel SAM does not undergo phase separation and consists predominantly of intermixed phases with adjustable surface density of quite flexible terpyridine anchor groups. The terpyridine–PdII anchors are not only available for a future deposition of the next layer, but the metal ions also represent a sensitive probe for the accessibility of the terpyridyl groups. PY - 2012 DO - https://doi.org/10.1021/la301644r SN - 0743-7463 SN - 1520-5827 VL - 28 IS - 29 SP - 10755 EP - 70763 PB - American Chemical Society CY - Washington, DC AN - OPUS4-26430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Manfred A1 - Weise, H. T1 - Farbmessung mit dem "Zusatzgerät MPA" PY - 1953 SN - 0014-7680 VL - 2 IS - 3/4 SP - 121 EP - 126 PB - Musterschmidt CY - Göttingen AN - OPUS4-30016 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Buzolin, R. H. A1 - Richter, Tim A1 - Pixner, F. A1 - Rhode, Michael A1 - Schroepfer, Dirk A1 - Enzinger, N. T1 - Microstructure characterisation of multi-principal element alloys welds produced by electron beam welding N2 - This work explores the feasibility of producing bead-on-plate welds of a CrCoNi medium entropy alloy and a CrMnFeCoNi high entropy alloy using electron beam welding. The alloys were welded in two states: one in an as-cold-rolled condition and the other in an annealed condition. In addition, the materials are welded with two different parameters. The FCC microstructure of the welds is investigated using scanning electron microscopy assisted by energy-dispersive X-ray spectroscopy and electron-backscattered diffraction. The impact of the weld on the microstructure is discussed. The heat-affected zone is negligible for the annealed condition of both medium and high entropy alloys since there is no driving force for recrystallisation and the exposure time to high temperature is insufficient for grain coarsening. The texture formed in the fusion zone is also discussed and compared to the texture in the base metal and the heat-affected zone. Although the grain growth along the (100) crystallographic direction is preferential in all cases, the crystallographic texture type differs from each weld. Higher hardness values are measured in the medium entropy alloy’s base metal and fusion zone than in the high entropy alloy. KW - Multi-principal element alloy KW - Electron backscattered diffraction KW - Electron beam welding KW - High-entropy alloy KW - Microstructure characterization PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568129 DO - https://doi.org/10.1016/j.matdes.2023.111609 SN - 1873-4197 VL - 225 SP - 1 EP - 14 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-56812 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Holzweber, Markus A1 - Heinrich, T. A1 - Kunz, V. A1 - Richter, S. A1 - Traulsen, C.H.-H. A1 - Schalley, C.A. A1 - Unger, Wolfgang T1 - Principal component analysis (PCA)-assisted time-of-flight secondary-ion mass spectrometry (ToF-SIMS): a versatile method for the investigation of self-assembled monolayers and multilayers as precursors for the bottom-up approach of nanoscaled devices N2 - The production of high-quality self-assembled monolayers (SAMs) followed by layer-by-layer (LbL) self-assembly of macrocycles is essential for nanotechnology applications based on functional surface films. To help interpret the large amount of data generated by a standard ToF-SIMS measurement, principal component analysis (PCA) was used. For two examples, the advantages of a combination of ToF-SIMS and PCA for quality control and for the optimization of layer-by-layer self-assembly are shown. The first example investigates how different cleaning methods influence the quality of SAM template formation. The second example focuses on the LbL self-assembly of macrocycles and the corresponding stepwise surface modification. KW - ToF-SIMS KW - Principal component analysis KW - Self assembled monolayer KW - Layer by layer PY - 2014 DO - https://doi.org/10.1021/ac500059a SN - 0003-2700 SN - 1520-6882 VL - 86 IS - 12 SP - 5740 EP - 5748 PB - American Chemical Society CY - Washington, DC AN - OPUS4-30963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, M.D. A1 - Becker-Ross, H. A1 - Okruss, M. A1 - Geisler, S. A1 - Florek, S. A1 - Richter, Silke A1 - Meckelburg, Angela T1 - Direct determination of fluorine in niobium oxide using slurry sampling electrothermal high-resolution continuum source molecular absorption spectrometry N2 - Aiming for a round-robin test, a new method for the direct determination of fluorine in niobium oxide has been developed. It is based on the use of high-resolution molecular absorption spectra of calcium mono-fluoride (CaF) generated in the graphite tube, combined with the slurry sampling technique. The absorption measurement was performed at the 606.44 nm CaF rotational line. By using graphite tubes with zirconium carbide (ZrC) modified platform, the molecular absorption sensitivity of CaF has been improved by a factor of 20, and no additional chemical modifier was necessary. Generally, non-spectral interferences were observed in the presence of HCl, H2SO4, and H3PO4. For HCl, additional spectral interference occurred due to an overlap of the absorption spectra of CaF and CaCl. However, due to the absence of these mentioned substances in the current material, such interferences do not exist for this application. The characteristic mass found for the CaF 606.44 nm line was 0.1 ng; the limit of detection was 5 mg fluorine per kg solid sample (3σ criterion). The results obtained by the method were within the range of certified values. Comparing to the classical method such as the pyrohydrolysis-photometric method, the developed new method showed clear advantages regarding sensitivity and specificity. The time requirement for one sample analysis was strongly shortened from several hours to only some minutes. KW - Continuum source molecular absorption spectrometry KW - Fluorine determination KW - Niobium oxide KW - Slurry sampling PY - 2014 DO - https://doi.org/10.1016/j.sab.2014.02.005 SN - 0584-8547 SN - 0038-6987 VL - 94-95 SP - 34 EP - 38 PB - Elsevier CY - Amsterdam AN - OPUS4-30655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balzer, M. A1 - Fenker, M. A1 - Kappl, H. A1 - Müller, Thoralf A1 - Heyn, A. A1 - Heiss, A. A1 - Richter, A. T1 - Corrosion protection of steel substrates by magnetron sputtered TiMgN hard coatings: Structure, mechanical properties and growth defect related salt spray test results N2 - Hard and wear resistant coatings deposited by PVD techniques have been characterized for decades for their capabilities to protect steel substrates from corrosion. In the present work the effect of Mg incorporated into TiN coatings is described in terms of the corrosion behavior as well as the mechanical and structural properties. TiN and TiMgN films with Mg contents between 10 and 35 at.% were deposited onto mirror polished 100Cr6 (1.3505) steel samples with 2.5 and 5 μm thickness by using DC magnetron sputtering. The corrosion protection capabilities of the coatings were characterized by neutral salt spray (NSS) test, considering the amounts and sizes of growth defects inherent in each coated sample as determined by a recently developed optical scan method (Large Area High Resolution mapping). The defect data were statistically analyzed for improved interpretation of NSS test results. Chosen growth defects were additionally analyzed by focused ion beam technique. Furthermore the coating composition and morphology, the hardness and the tribological behavior were characterized. Polished steel samples coated with 2.5 μm TiMgN containing about 35 at.% Mg were in the plane free of corrosion after 24 h in a NSS test. TiMgN with 10 or 20 at.% Mg only provided a slightly improved corrosion protection in relation to pure TiN coatings, which was limited to certain types of growth defects. The highest Mg containing coatings exhibited a decreased hardness down to 1200 or 1800 HV depending on type of deposition (HV 1200: Ti- and Mg-target with rotating substrate holder, 1800: Mg-plugged Ti-target with static substrate holder), but also showed a strongly improved wear resistance against Al2O3 related to pure TiN. By analyzing the NSS test results it was found that the corrosion behavior of the coated samples did not only depend strongly on the Mg content, but also on the sample individual defect concentrations. Therefore this subject is extensively discussed. KW - Physical vapour deposition (PVD) KW - Corrosion KW - Growth defects KW - Pinholes KW - Magnesium KW - TiMgN PY - 2018 DO - https://doi.org/10.1016/j.surfcoat.2018.05.037 SN - 0257-8972 VL - 349 IS - 9 SP - 82 EP - 92 PB - Elsevier B.V. AN - OPUS4-45712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elordui-Zapatarietxe, S. A1 - Fettig, Ina A1 - Richter, Janine A1 - Philipp, Rosemarie A1 - Vanermen, G. A1 - Monteyne, E. A1 - Boom, G. A1 - Emteborg, H. T1 - Preparation and evaluation of sufficiently homogeneous and stable reference materials for priority hazardous substances in whole water N2 - We have prepared and evaluated three whole water test materials containing eight polycyclic aromatic hydrocarbons (PAHs), six polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) with respect to homogeneity and short-term stability. The test materials were used as samples in two inter-laboratory comparisons. The materials were composed of natural mineral water and model suspended particulate matter (SPM) containing the target compounds at ng L-1 levels. The expanded uncertainty of the estimated mass concentrations in the final test materials was obtained by combining contributions from the homogeneity, the stability and the model SPM characterization. The whole water materials were sufficiently homogeneous and stable at 4 °C for their intended use. In total, 12 out of 15 investigated target parameters could be assessed to be present with a relative combined expanded uncertainty below 25 %. The outcome of the two interlaboratory comparisons confirmed the good quality of the test materials and the level of uncertainties associated with the estimated mass concentrations. These findings are an important contribution towards the development of whole water matrix reference materials certified for PAH, PBDE and TBT in support of the Water Framework Directive of the European Union. KW - Reference material KW - Referenzmaterial KW - Water Framework Directive KW - Wasserrahmenrichtlinie KW - Whole water sample KW - Gesamtwasserprobe PY - 2016 DO - https://doi.org/10.1007/s00769-015-1189-1 SN - 0949-1775 SN - 1432-0517 VL - 21 IS - 2 SP - 113 EP - 120 PB - Springer AN - OPUS4-35728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Janine A1 - Elordui-Zapatarietxe, S. A1 - Emteborg, H. A1 - Fettig, Ina A1 - Cabillic, J. A1 - Alasonati, E. A1 - Gantois, F. A1 - Swart, C. A1 - Gokcen, T. A1 - Tunc, M. A1 - Binici, B. A1 - Rodriguez-Cea, A. A1 - Zuliani, T. A1 - Gonzalez Gago, A. A1 - Pröfrock, D. A1 - Nousiainen, M. A1 - Sawal, G. A1 - Buzoianu, M. A1 - Philipp, Rosemarie T1 - An interlaboratory comparison on whole water samples N2 - The European Water Framework Directive 2000/60/EC requires monitoring of organic priority pollutants in so-called whole water samples, i.e. in aqueous nonfiltered samples that contain natural colloidal and suspended particulate matter. Colloids and suspended particles in the liquid phase constitute a challenge for sample homogeneity and stability. Within the joint research project ENV08 ‘‘Traceable measurements for monitoring critical pollutants under the European Water Framework Directive 2000/60/EC’’, whole water test materials were developed by spiking defined amounts of aqueous slurries of ultrafinely milled contaminated soil or sediment and aqueous solutions of humic acid into a natural mineral water matrix. This paper presents the results of an European-wide interlaboratory comparison (ILC) using this type of test materials. Target analytes were tributyltin, polybrominated diphenyl ethers and polycyclic aromatic hydrocarbons in the ng/L concentration range. Results of the ILC indicate that the produced materials are sufficiently homogeneous and stable to serve as samples for, e.g. proficiency testing or method validation. To our knowledge, this is the first time that ready-to-use water materials with a defined amount of suspended particulate and colloidal matter have been applied as test samples in an interlaboratory exercise. These samples meet the requirements of the European Water Framework Directive. Previous proficiency testing schemes mainly employed filtered water samples fortified with a spike of the target analyte in a water-miscible organic solvent. KW - Water Framework Directive KW - Wasserrahmenrichtlinie KW - Interlaboratory comparison KW - Ringversuch KW - Whole water sample KW - Gesamtwasserprobe PY - 2016 DO - https://doi.org/10.1007/s00769-015-1190-8 SN - 0949-1775 SN - 1432-0517 VL - 21 IS - 2 SP - 121 EP - 129 PB - Springer AN - OPUS4-35730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, S. A1 - Traulsen, C. H.-H. A1 - Heinrich, Thomas A1 - Poppenberg, J. A1 - Leppich, C. A1 - Holzweber, Markus A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Sequence-programmable multicomponent multilayers of nanometer-sized tetralactam macrocycles on gold surfaces N2 - Multicomponent multilayers have been deposited on gold surfaces by metal-ion-mediated layer-by-layer self-assembly of differently functionalized tetralactam macrocycles. The layer stack can be programmed with respect to the sequences of metal ions and macrocycles by the deposition sequence. KW - Organic layer KW - XPS KW - SIMS KW - NEXAFS PY - 2013 DO - https://doi.org/10.1021/jp405492v SN - 1932-7447 SN - 1089-5639 VL - 117 IS - 37 SP - 18980 EP - 18985 PB - Soc. CY - Washington, DC AN - OPUS4-32576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elordui-Zapatarietxe, S. A1 - Fettig, Ina A1 - Richter, Janine A1 - Philipp, Rosemarie A1 - Gantois, F. A1 - Lalère, B. A1 - Swart, C. A1 - Emteborg, H. T1 - Interaction of 15 priority substances for water monitoring at ng L-1 levels with glass, aluminium and fluorinated polyethylene bottles for the containment of water reference materials N2 - Certified water reference materials are currently not available for most of the hydrophobic organic pollutants listed in the EU Water Framework Directive. To find the most suitable container type for subsequent reference material productions, feasibility studies for the preparation of waters with polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) close to environmental quality standards in water have been performed. Due to the hydrophobic nature of these compounds and their tendency to adsorb onto container walls, an adequate selection of the most appropriate material for containment, storage and transport of water reference materials is crucial. Three different materials (aluminium, amber glass and fluorinated polyethylene, FPE) and three volumes (500/600 mL, 1000/1200 mL and 2000/3000 mL, depending on commercial availability) were tested at ng L-1 level of the target compounds. FPE shows by far the highest loss of analytes due to adsorption onto the container walls for all compounds studied. Aluminium and glass are equally suited for PAHs and PBDEs, but aluminium is unsuitable as container material for TBT due to acid cleaning requirements. The volume of the containers had no dramatic effect on the adsorption behaviour of target compounds for the different volumes tested. KW - Water framework directive KW - Reference materials KW - Hydrophobic organic pollutants KW - Bottles KW - Adsorption KW - Glass KW - Aluminium KW - Fluorinated polyethylene PY - 2015 DO - https://doi.org/10.1007/s00769-015-1150-3 SN - 0949-1775 SN - 1432-0517 VL - 20 IS - 6 SP - 447 EP - 455 PB - Springer CY - Berlin AN - OPUS4-34946 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poppenberg, J. A1 - Richter, S. A1 - Traulsen, Ch. H.-H. A1 - Darlatt, Erik A1 - Baytekin, B. A1 - Heinrich, Thomas A1 - Deutinger, P. M. A1 - Huth, K. A1 - Unger, Wolfgang A1 - Schalley, Ch. T1 - Programmable multilayers of nanometer-sized macrocycles on solid support and stimuli-controlled on-surface pseudorotaxane formation N2 - Mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes are capable of mechanical motion on the nanoscale and are therefore promising prototypes for molecular machines in recent nanotechnology. However, most of the existing examples are isotropically distributed in solution, which prohibits concerted movement and with it the generation of macroscopic effects. Thus, arranging them in ordered arrays is of huge interest in recent research. We report the deposition of quite densely packed multilayers of tetralactam macrocycles on gold surfaces by metal-coordinated layer-by-layer self-assembly. Linear dichroism effects in angle-resolved NEXAFS spectra indicate a preferential orientation of the macrocycles. The sequence of the metal ions can be programmed by the use of different transition metal ions at each deposition step. Additionally, reversible on-surface pseudorotaxane formation was successfully realized by repeated uptake and release of axle molecules inside the macrocycles cavities. KW - NEXAFS KW - XPS KW - Supramolecular Chemistry KW - Multilayers KW - Pyridine KW - UV/Vis KW - Macrocycles KW - Pseudorotaxanes PY - 2013 DO - https://doi.org/10.1039/c3sc50558h VL - 4 IS - 8 SP - 3131 EP - 3139 AN - OPUS4-42668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogl, Jochen A1 - Kipphardt, Heinrich A1 - Richter, Silke A1 - Bremser, Wolfram A1 - Arvizu Torres, M. A1 - Lara Manzano, J. A1 - Buzoianu, M. A1 - Hill, S. A1 - Petrov, P. A1 - Goenaga-Infante, H. A1 - Sargent, M. A1 - Fisicaro, P. A1 - Labarraque, G. A1 - Zhou, T. A1 - Turk, G. C. A1 - Winchester, M. A1 - Miura, T. A1 - Methven, B. A1 - Sturgeon, R. A1 - Jährling, R. A1 - Rienitz, O. A1 - Mariassy, M. A1 - Hankova, Z. A1 - Sobina, E. A1 - Krylov, A. I. A1 - Kustikov, Y. A. A1 - Smirnov, V. V. T1 - Establishing comparability and compatibility in the purity assessment of high purity zinc as demonstrated by the CCQM-P149 intercomparison N2 - For the first time, an international comparison was conducted on the determination of the purity of a high purity element. Participants were free to choose any analytical approach appropriate for their institute’s applications and services. The material tested was a high purity zinc, which had earlier been assessed for homogeneity and previously used in CCQM-K72 for the determination of six defined metallic impurities. Either a direct metal assay of the Zn mass fraction was undertaken by EDTA titrimetry, or an indirect approach was used wherein all impurities, or at least the major ones, were determined and their sum subtracted from ideal purity of 100 %, or 1 kg/kg. Impurity assessment techniques included glow discharge mass spectrometry, inductively coupled plasma mass spectrometry and carrier gas hot extraction/combustion analysis. Up to 91 elemental impurities covering metals, non-metals and semi-metals/metalloids were quantified. Due to the lack of internal experience or experimental capabilities, some participants contracted external laboratories for specific analytical tasks, mainly for the analysis of non-metals. The reported purity, expressed as zinc mass fraction in the high purity zinc material, showed excellent agreement for all participants, with a relative standard deviation of 0.011 %. The calculated reference value, w(Zn) = 0.999 873 kg/kg, was assigned an asymmetric combined uncertainty of + 0.000025 kg/kg and – 0.000028 kg/kg. Comparability amongst participating metrology institutes is thus demonstrated for the purity determination of high purity metals which have no particular difficulties with their decomposition / dissolution process when solution-based analytical methods are used, or which do not have specific difficulties when direct analysis approaches are used. Nevertheless, further development is required in terms of uncertainty assessment, quantification of non-metals and the determination of purity of less pure elements and/or for those elements suffering difficulties with the decomposition process. KW - Purity assessment KW - Direct metal assay KW - Impurity assessment KW - Non-metal analysis KW - High-purity elements KW - SI-traceability PY - 2018 DO - https://doi.org/10.1088/1681-7575/aaa677 SN - 1681-7575 SN - 0026-1394 VL - 55 IS - 2 SP - 211 EP - 221 PB - Institute of Physics Publishing CY - Bristol AN - OPUS4-44257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Schartel, Bernhard A1 - Richter, K. H. A1 - Böhning, Martin ED - Morgan, A. B. ED - Wilkie, C. A. ED - Nelson, G. L. T1 - Synergistic use of talc in halogen-free flame retarded polycarbonate/Acrylonitrile-butadiene-styrene blends N2 - Pyrolysis, flammability, fire behavior, melt viscosity, and gas diffusion of bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) were investigated, with bisphenol A bis(diphenyl phosphate) (BDP), with 10 wt.% talc and with BDP in combination with 5, 10 and 20 wt.% talc, respectively. Compared to PC/ABS, PC/ABS + BDP results in an increased decomposition temperature of PC, a higher char yield, a significantly increased LOI, a V-0 classification in UL 94, a reduced peak heat release rate (pHRR), and a reduced total heat release (THR) in the cone calorimeter. This efficient flame retardancy is due to mechanisms in both the gas and condensed phases. PC/ABS + 10 wt.% talc shows a decrease in the PC decomposition temperature. The fire behavior is improved in part compared to PC/ABS, with an increased LOI and reduced pHRR. PC/ABS + BDP + 10 wt.% talc shows a strong synergism in LOI, a V-0 classification, and a decrease in pHRR, whereas THR is slightly increased compared to PC/ABS + BDP. Talc decreases the gas diffusion and enhances the flow limit for low shear rates, both of which influence the pyrolysis and flammability results. Further, talc improves the protection properties of the fire residues. Nevertheless it also partly suppresses flame inhibition and the charring effect of BDP. The synergism between BDP and talc in LOI is obtained even for low talc loadings in PC/ABS + BDP + talc, whereas for higher loadings saturation is observed. KW - Flame retardancy KW - PC/ABS KW - Aryl phosphate KW - Talc PY - 2012 SN - 978-0-8412-2780-4 DO - https://doi.org/10.1021/bk-2012-1118.ch002 N1 - Serientitel: ACS Symposium Series – Series title: ACS Symposium Series VL - 1118 IS - Chapter 2 SP - 15 EP - 36 PB - Oxford University Press AN - OPUS4-27563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tannenberg, Robert A1 - Paul, Martin A1 - Röder, Bettina A1 - Gande, S. L. A1 - Sreeramulu, S. A1 - Saxena, K. A1 - Richter, C. A1 - Schwalbe, H. A1 - Swart, C. A1 - Weller, Michael G. T1 - Chemiluminescence biosensor for the determination of cardiac troponin I (cTnI) N2 - Cardiac troponin I (cTnI) is a crucial biomarker for diagnosing cardiac vascular diseases, including acute myocardial infarction (AMI). This study presents a proof-of-concept chemiluminescence-based immunosensor for rapid and accurate measurement of cTnI, with the potential for online monitoring. The immunosensor incorporates a flow cell design and a sensitive complementary metal-oxide-semiconductor (CMOS) camera for optical readout. A microfluidic setup was established to enable selective and quasi-online determination of cTnI within ten minutes. The sensor was tested with recombinant cTnI in phosphate buffer, demonstrating measurements in the concentration range of 2–25 µg/L, with a limit of detection (LoD) of 0.6 µg/L (23 pmol/L) achieved using the optimized system. The immunosensor exhibited high selectivity, as no cross-reactivity was observed with other recombinant proteins such as cTnT and cTnC at a concentration of 16 µg/L. Measurements with diluted blood plasma and serum yielded an LoD of 60 µg/L (2.4 nmol/L) and 70 µg/L (2.9 nmol/L), respectively. This biosensor offers a promising approach for the rapid and sensitive detection of cTnI, contributing to the diagnosis and management of acute myocardial infarction and other cardiac vascular diseases. N2 - Das kardiale Troponin I (cTnI) ist ein wichtiger Biomarker für die Diagnose von Herz-Kreislauf-Erkrankungen, einschließlich des akuten Myokardinfarkts (AMI). In dieser Studie wird ein auf Chemilumineszenz basierender Immunsensor für die schnelle und genaue Messung von cTnI vorgestellt, der das Potenzial für eine Online-Überwachung hat. Der Immunsensor besteht aus einer Durchflusszelle und einer empfindlichen CMOS-Kamera (Complementary Metal-Oxide-Semiconductor) zur optischen Detektion. Es wurde ein mikrofluidischer Aufbau entwickelt, der eine selektive und quasi Online-Bestimmung von cTnI innerhalb von zehn Minuten ermöglicht. Der Sensor wurde mit rekombinantem cTnI in Phosphatpuffer getestet und zeigte einen Messbereich von 2-25 µg/L, wobei mit dem optimierten System eine Nachweisgrenze (LoD) von 0,6 µg/L (23 pmol/L) erreicht wurde. Der Immunsensor zeigte eine hohe Selektivität, da keine Kreuzreaktivität mit anderen rekombinanten Proteinen wie cTnT und cTnC bei einer Konzentration von 16 µg/L beobachtet wurde. Messungen mit verdünntem Blutplasma und Serum ergaben einen LoD von 60 µg/L (2,4 nmol/L) bzw. 70 µg/L (2,9 nmol/L). Dieser Biosensor bietet einen vielversprechenden Ansatz für den schnellen und empfindlichen Nachweis von cTnI, der zur Diagnose und Behandlung des akuten Myokardinfarkts und anderer kardialer Gefäßerkrankungen beitragen kann. KW - Acute myocardial infarction KW - Heart attack KW - Emergency KW - Diagnosis KW - Cardiac troponin KW - Biomarker KW - Immunosensor KW - Biosensor KW - Chemiluminescence KW - Luminol KW - Peroxidase KW - Monoclonal antibodies KW - Flow injection immunoassay KW - Immunometric assay KW - Immunometric biosensor KW - Microfluidic system KW - Monolithic column KW - Online biosensor PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575471 DO - https://doi.org/10.3390/bios13040455 SN - 2079-6374 VL - 13 IS - 4 SP - 1 EP - 20 PB - MDPI CY - Basel AN - OPUS4-57547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Traulsen, C. H.-H. A1 - Kunz, V. A1 - Heinrich, Thomas A1 - Richter, S. A1 - Holzweber, Markus A1 - Schulz, A. A1 - von Krbek, L. K. S. A1 - Scheuschner, U. T. J. A1 - Poppenberg, J. A1 - Unger, Wolfgang A1 - Schalley, C. A. T1 - Synthesis and coordinative layer-by-layer deposition of pyridine-functionalized gold nanoparticles and tetralactam macrocycles on silicon substrates N2 - Coordination chemistry was applied to deposit pyridine-functionalized gold nanoparticles on silicon substrates. The particles were synthesized through the Brust/Schiffrin route with a subsequent ligand exchange reaction yielding well-defined particles of two different sizes. Multilayer deposition was carried out on a pyridine-terminated SAM, anchored on a hydroxyl-terminated silicon surface. Analogously, Hunter/Vögtle-type tetralactam macrocycle multilayers were deposited as well as mixed layers containing both either in an alternating sequence or as a macrocycle multilayer with a terminating nanoparticle layer. These composite layers were examined with respect to their ability to bind squaraine axles in the macrocycle cavities. The amount of guest bound is higher for the composite layer with alternating macrocycles and nanoparticles. KW - Layer-by-layer deposition KW - Functionalized Au nanoparticles KW - SEM KW - TEM KW - DLS KW - XPS KW - NEXAFS KW - ToF-SIMS KW - IR KW - UV-vis PY - 2013 DO - https://doi.org/10.1021/la403222x SN - 0743-7463 SN - 1520-5827 VL - 29 IS - 46 SP - 14284 EP - 14292 PB - American Chemical Society CY - Washington, DC AN - OPUS4-29699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hassler, J A1 - Matschat, Ralf A1 - Richter, Silke A1 - Barth, P. A1 - Detcheva, A.K. A1 - Waarlo, H.-J. T1 - Determination of 22 trace elements in high-purity copper including Se and Te by ETV-ICP OES using SF6, NF3, CF4 and H2 as chemical modifiers N2 - In supplementary work to the one published earlier, experiments with SF6, NF3, CF4 and H2 as new modifier gases for the matrix studied were performed. Our investigations were continued to improve the described analytical method and to achieve additional insights into the mechanism of analyte release. Our new survey is split in two parts. At first fluorinating modifiers were used to investigate the behaviour of a variety of trace elements (Ag, Al, As, Au, Bi, Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, Sb, Se, Si, Sn, Te, Ti, Zn and Zr). Most of them (exceptions Au, Se, and Te) could be effectively released from the copper matrix by thermo-halogenation reactions and by partial sub-sample evaporation. Using SF6 and NF3 as modifier gases, low limits of quantification (LOQs) were achieved for the 19 well released trace elements (typical ≤0.1 mg kg-1). Most elements (exceptions Ag, Mg, and Ni) could be calibrated by using aqueous calibration solutions without any sample pretreatment. For the trace determination of Se, Te, and Au, a further analytical method of ETV-ICP OES is described in the second part based on thermo-hydrogenation reactions by using a hydrogen/argon mixture as a modifier gas. The determination of Se and Te with very high analytical performance (LOQ < 0.1 mg kg-1) can either be carried out in a second analytical step succeeding the halogenation procedure, or the sub-sample is directly treated with H2 without previous halogenation procedure whereby the sub-sample can either be partially or totally evaporated. In this case some other analytes (Ag, Au, As, Bi, Cd, Fe, Mg, Ni, Pb, Sb, Sn, and Zn) can additionally be quantified simultaneously with Se and Te. KW - Pure Cu material KW - Electrothermal vaporization KW - Optical-emission spectrometry KW - Plasma-mass-spectrometry KW - Atomic-absorption spectrophotometry KW - Graphite-furnace AAS KW - Pure copper KW - Spectrochemical analysis KW - Precise determination KW - Sample introduction KW - Silicon-carbide PY - 2016 DO - https://doi.org/10.1039/C5JA00240K SN - 0267-9477 SN - 1364-5544 VL - 31 IS - 3 SP - 642 EP - 657 PB - Royal Society of Chemistry CY - London AN - OPUS4-35133 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pisonero, J. A1 - Fandino, J. A1 - Nordlien, J. H A1 - Richter, Silke A1 - Pfeifer, Jens A1 - Quarles, C. D. A1 - Gonzalez, J. A1 - Jakubowski, Norbert A1 - Bordel, N. T1 - Improving the analytical performance of pulsed-GD-SFMS for multi-elemental depth profile analysis of heat-treated Zn coatings on extruded aluminium N2 - The formation of diffusion layers on Zn layers deposited on Al substrates is mainly used to prevent corrosion effects. Evaluation of the influence exerted by different coating methodologies and heat treatments on the formation of these diffusion layers is of great interest for the aluminium industry. Particularly, multi-elemental in-depth distributions of major, minor and trace elements in Zn-coatings is highly demanded before and after heat treatments. A fast characterization of these materials require a direct solid analytical technique able to provide high sensitivity and high depth resolution. For this purpose, an improved analytical method based on the use of pulsed glow discharge sector field mass spectrometry (pulsed-GD-SFMS) is investigated. Glow discharge operating parameters (e.g. pulse duration, pulse frequency), glow discharge source design (e.g. flow tube lengths), and SFMS mass spectra acquisition conditions (e.g. integration time) are evaluated to achieve low sputtering rates, high mass spectra acquisition rates and improved depth resolution. At the optimize conditions Zn coatings deposited by arc-spray and electrodeposition are analysed before and after heat treatments to evaluate the diffusion of different key elements. Moreover, results are validated using femtosecond laser ablation (fs-LA)-ICP-MS, which provides additional information about the heterogeneous distribution of some elements in the Zn coatings. KW - GDMS KW - Pulsed-GD-SFMS KW - Depht profiling KW - Zn KW - Aluminium PY - 2019 DO - https://doi.org/10.1039/c9ja00189a VL - 34 IS - 11 SP - 2252 EP - 2260 PB - Royal Society of Chemistry CY - London AN - OPUS4-49451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Buzolin, R.H. A1 - Richter, Tim A1 - Pixner, F. A1 - Rhode, Michael A1 - Schroepfer, Dirk A1 - Enzinger, N. T1 - Microstructure and texture characterisation of friction stir welded CoCrNi and CoCrFeMnNi multi-principle element alloys N2 - This work investigates the microstructure formed in friction stir welds of FCC alloys, focused on two multiprincipal alloys: a CoCrFeMnNi high-entropy alloy (HEA) and a CoCrNi medium-entropy alloy (MEA). A commercial stainless steel AISI 304 is used for comparison. The largest nugget was formed in the MEA, while the smallest was formed in the HEA. Grain refinement occurs in the stirred zone in all welds. Discontinuous dynamic recrystallisation is the predominant restoration mechanism during friction stir welding of the three investigated alloys. A sharp decrement in the Σ3 boundary fraction occurs in the stirred zone of the AISI 304 and HEA welds, while comparable values with the base metal are found for the MEA weld. The peak in the maximum index of crystallographic texture is observed on the advancing side of the stirred zone of the AISI 304 weld. A strong <001> θ-fibre texture is formed in the advancing side of the nugget in the AISI 304 from a well-established {123} <634> S-type texture in the base metal. Multiple crystallographic texture components without specific fibres are identified in most regions of the welds, indicating the complex shear path history during friction stir welding. KW - Microstructure KW - Multiple principal element alloy KW - Friction stir welding KW - Electron backscattered diffraction KW - Crystallographic texture PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572987 DO - https://doi.org/10.1016/j.mtcomm.2023.105870 VL - 35 SP - 1 EP - 14 PB - Elsevier Ltd. CY - Amsterdam (NL) AN - OPUS4-57298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Altmann, Korinna A1 - Abusafia, A A1 - Bannick, C-G A1 - Braun, U A1 - Crasselt, Claudia A1 - Dittmar, S A1 - Fuchs, M A1 - Gehde, M A1 - Hagendorf, C A1 - Heller, C A1 - Herper, D A1 - Heymann, S A1 - Kerndorff, A A1 - Knefel, M A1 - Jekel, M A1 - Lelonek, M A1 - Lunkenbein, T A1 - Obermaier, N A1 - Manhart, M A1 - Meurer, Maren A1 - Miclea, P-T A1 - Paul, A A1 - Richter, S A1 - Ricking, M A1 - Rohner, C A1 - Ruhl, A A1 - Sakai, Y A1 - Saravia Arzabe, C A1 - Scheid, C A1 - Schmitt, M A1 - Schnarr, M A1 - Schwertfirm, F A1 - Steinmetz, H A1 - Wander, Lukas A1 - Wiesner, Yosri A1 - Zechmeister, L T1 - RUSEKU - Repräsentative Untersuchungsstrategien für ein integratives Systemverständnis von spezifischen Einträgen von Kunststoffen in die Umwelt : Abschlussbericht N2 - Im Verbundprojekt RUSEKU wurde die Probenahme von Wasserproben entscheidend weiterentwickelt. Wichtig ist hierbei zu gewährleisten, dass genügend Merkmalsträger in jeder Probe untersucht werden. Es muss daher eine für den Probenahmeort repräsentative Beprobung hinsichtlich des Wasservolumens in Abhängigkeit der Partikelanzahl gewährleistet sein. Das Hauptaugenmerk lag im vorliegenden Projekt auf einer praxisnahen Beprobungsstrategie. Es wurden verschiedene Konzepte ausprobiert. • Grundsätzlich hat sich gezeigt, dass eine Stichprobe eine Momentaufnahme des MP-Massengehaltes zeigt. Es wird eine hohe Statistik, also eine Vielzahl an Messungen am gleichen Probenahmeort, benötigt, um eine valide Aussage über den MP-Gehalt zu machen. • Es zeigt sich, dass eine integrale Probenahme über mehrere Wochen mit dem SK routinemäßig möglich ist. Die erfassten MP-Massen sind reproduzierbar und robust. • Die DFZ ist für Stichproben geeignet. Partikel < 50 µm werden eventuell unterschätzt • Die fraktionierte Filtration kann für Stich- und Mischproben direkt im Feld genutzt werden. Fraktionen von 10 und 5 µm werden später im Labor Vakuum filtriert. Es erfolgt eine Fraktionierung der Probe mit Siebmaschenweiten von 1000, 500, 100, 50, 10 und 5 µm. • Die fraktionierte Filtration kann auch anschließend an die Beprobung mit dem SK zur Anwendung kommen. Wird die mit dem SK gewonnene Wasserprobe fraktioniert filtriert, kann neben einem MP-Gesamtgehalt auch eine Einschätzung über die Partikelgrößen gewonnen werden. • Für Wässer mit geringen Partikelzahlen wurde ein Messfiltertiegel entwickelt. Dieser hat eine Maschenweite von 6 µm. Seine Anwendung kann mögliche Verluste beim Transferieren vom Probenahmetool zum Messgefäß und mögliche Kontaminationen reduzieren. Die Optimierung der Probenahmestrategie wurde durch Modellversuche und Simulationen unterstützt. Modellversuche zum Sinkverhalten und Simulationen von MP in realen Gewässern verdeutlichten das komplexe Verhalten der Partikel. Es konnte gezeigt werden, dass Partikel ab einer bestimmten Größe (und kleiner) bei genügend starker Turbulenz sich in der Wassersäule unabhängig von ihrer Dichte verhalten und so auch MP mit kleiner Dichte (z.B. PE) in der gesamten Wassersäule zu finden sind. Es konnte mit dem TEM die Existenz von NP gezeigt werden. Ein wesentlicher Aspekt des RUSEKU Projektes war die Beprobung realer Kompartimente. Beprobt wurde neben Oberflächengewässern, das urbane Abwassersystem der Stadt Kaiserslautern, Waschmaschinenabwasser und Flaschenwasser. • In Oberflächengewässern wurde hauptsächlich PE gefunden. Je nach Probe und Gewässer konnten auch PP, PS, PET, PA, SBR und Acrylate nachgewiesen werden. • Im urbanen Abwassersystem der Stadt Kaiserslautern konnte an allen Probenahmestandorten MP nachgewiesen werden. Es wurde hauptsächlich PE, neben geringeren Mengen an PP, PS und SBR gefunden. Nach einem Regenereignis war der SBR Anteil deutlich erhöht. • Die Beprobung eines realen Wäschepostens, bestehend aus T-Shirts und Hemden mit PA/CO oder PES/CO Mischgewebe, zeigte einen PA- und PES-Austrag im Waschwasser. Der überwiegende Teil der detektierten Fasern ist aber auf Baumwolle zurückzuführen. Reine gravimetrische Messungen zur Detektion von MP führen zu einer starken Überschätzung. • In Flaschenwasser (PET-Flaschen) konnte MP detektiert werden. PET wurde nur im stillen Mineralwasser, nicht in Mineralwasser mit Kohlensäure gefunden werden. Teilweise wurde auch das MP-Material des Verschlusses im Wasser detektiert. • Für Luftproben konnte ein Aufbau zur größenselektiven Beprobung getestet werden. Neben der Probenahme hat das Projekt auch gezeigt, dass die TED-GC/MS geeignet für die MP-Detektion im Routinebetrieb ist. Die TED-GC/MS konnte weiter optimiert werden. Es wurden MP-Massen bestimmt. Im Projekt wurden erste realitätsnahe Referenzmaterialien für die MP Detektion hergestellt. Die Herstellung von realitätsnahen Polymeren in ausreichender Homogenität und Menge hat sich als große Herausforderung herausgestellt. KW - Mikroplastik KW - Probennahme KW - TED-GC/MS KW - Fraktionierte Filtration KW - Mikroplastikreferenzmaterial PY - 2022 SP - 1 EP - 201 AN - OPUS4-57800 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -