TY - JOUR A1 - Scherer, Christian A1 - Utech, S. A1 - Scholz, S. A1 - Noskov, S. A1 - Kindervater, P. A1 - Graf, R. A1 - Thünemann, Andreas A1 - Maskos, Michael T1 - Synthesis, characterization and fine-tuning of bimodal poly(organosiloxane) nanoparticles N2 - The acid catalyzed sol–gel type synthesis of polyorganosiloxane core-shell nanoparticles with removable PDMS core in aqueous dispersion leads to the inherent formation of a bimodal size distribution with smaller spheres having approximately 26 nm radii and larger nanoparticles with 60 nm in radius. The origin of the self-organized bimodality is investigated and finally attributed to a combination of stabilization of the growing particles due to i) a miniemulsion-type stabilization by the ultrahydrophobe PDMS and ii) by surface co-stabilization by the employed surfactant. The significant influence of temperature, pH, stirrer speed and amount of the surfactant on the particle sizes allows for the design and fine-tuning of different nanoparticles sizes and distributions. KW - Nanoparticles KW - Polyorganosiloxane KW - Field-flow fractionation (FFF) PY - 2010 DO - https://doi.org/10.1016/j.polymer.2010.09.065 SN - 0032-3861 SN - 1873-2291 VL - 51 IS - 23 SP - 5432 EP - 5439 PB - Springer CY - Berlin AN - OPUS4-22476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tamura, T. A1 - Hosohata, S. A1 - Nakase, T. A1 - Kato, S. A1 - Scholz, Christian A1 - Woydt, Mathias T1 - High wear resistance DLC film under high pressure contact N2 - Diamond-like Carbon (DLC) is a hard film composed primarily of carbon and possessed amorphous structure. It is known to have superior tribological properties such as low friction, high wear resistance and anti-seizure. In addition, DLC film is now widely used in a various industrial application due to improvements in its adhesive property. This paper shows the DLC film with sputtering method has the durability under high pressure contact. T2 - 12. Machine design and tribology division meeting in JSME CY - Ehime-ken, Japan DA - 23.04.2012 KW - Diamond-like carbon KW - Slip-rolling test PY - 2012 SN - 1348-3919 N1 - Sprachen: Japanisch/Englisch - Languages: Japanese/English VL - 12-14 SP - 101 EP - 102 AN - OPUS4-25923 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholz, Christian A1 - Tamura, T. A1 - Hosohata, S. A1 - Nakase, T. A1 - Kato, S. A1 - Woydt, Mathias T1 - Null-Verschleiß an Hochleistungs-DLC-Schichten N2 - Die Wälzbeständigkeit und das Potential zur Reibungsminimierung von Hochleistungsdünnschichten wurden bereits in einer Vielzahl von Untersuchungen dargestellt. Insbesondere a-C:H Schichtsysteme konnten hierbei hervorragende Testresultate bei Hertzschen Kontaktpressungen bis zu Pomax = 4,2 GPa (Fn= 5 kN) im geschmierten Zustand bei 120°C Öltemperatur vorweisen. In der vorliegenden Arbeit konnte anhand von, bereits in der Industrie erfolgreich angewendeten, DLC-Hochleistungsdünnschichten in Überrollversuchen auf Zwei-Scheiben-Prüfständen zusätzlich sehr niedrige Verschleißkoeffizienten nachgewiesen werden. Bei der topografischen Untersuchung der Beschichtungen nach Versuchen wurden Verschleißkoeffizienten unterhalb von 10'10 mm3/Nm festgestellt. Die Versuche dazu wurden auf zwei verschiedenen Zwei-Scheiben-Tribometern (Amsler und Optimol Instruments) unter Hertzschen Kontaktpressungen von bis zu Pomax = 3,75 GPa (Fn = 4.400 N) bei 120°C Öltemperatur durchgeführt. Als industriell prozesssicheres Stoffsystem mit Null-Verschleiß Eigenschaften im geschmierten Reibungszustand unter Extrembedingungen bieten diese PVD-Schichten ein hohes Potential Anwendung im Zuge von Leichtbaustrategien im PKW-Bereich und anderen industriellen Applikationen zu finden. Die Oberflächen der Beschichtungen wurden hinsichtlich ihrer Topographie mittels taktiler Messtechnik und AFM untersucht. T2 - 53. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß CY - Göttingen, Germany DA - 24.09.2012 KW - Null-Verschleiß KW - DLC KW - Extrembeanspruchung KW - Dünnschichten PY - 2012 SN - 978-3-00-039201-6 SP - 44/1 EP - 44/15 CY - Aachen AN - OPUS4-26686 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Göbel, M. A1 - Kirsch, S. A1 - Schwarze, L: A1 - Schmidt, L. A1 - Scholz, H. A1 - Haußmann, J. A1 - Klages, M. A1 - Scholta, J. A1 - Markötter, Henning A1 - Alrwashdeh, S. A1 - Manke, I. A1 - Müller, Bernd R. T1 - Transient limiting current measurements for characterization of gas diffusion layers N2 - The water management in proton exchange membrane fuel cells (PEMFC) is strongly influenced by the design of the gas diffusion layers (GDL). Limiting current measurements in small-scale cells operating at high stoichiometries are useful to determine the oxygen transport resistance. The oxygen transport resistance increases, once water condenses inside the GDL. In this study a new electrochemical method for voltage loss estimation of GDL induced oxygen transport losses are presented. This new method, referred to as “transient limiting current” (TLC), is compared with the literature method. TLC allows a direct estimation of oxygen transport resistance at an arbitrarily conditioned state. This study also presents a case study of liquid water visualization of a PEM fuel cell with varying GDLs types. With the help of quasi in-situ synchrotron X-ray computed tomography and time resolved radiography measurements we investigate appearance and distribution of liquid water inside the GDLs under limiting current conditions. KW - In-situ characterization of GDLs KW - In-situ synchrotron X-ray computed tomography KW - In-situ synchrotron X-ray radiography KW - BAMline PY - 2018 DO - https://doi.org/10.1016/j.jpowsour.2018.09.003 SN - 0378-7753 SN - 1873-2755 VL - 402 SP - 237 EP - 245 PB - Elsevier B.V. AN - OPUS4-46552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jentsch, H. A1 - Schwartz, A. A1 - Basedau, Frank A1 - Bazrafshan, K. A1 - Döring, H. A1 - Großwig, S. A1 - Hofmann, Detlef A1 - Kowalle, G. A1 - Kusche, Nadine A1 - Lorenz, R. A1 - Pfeiffer, T. A1 - Sadaghiani, M.R.S. A1 - Scholz, E. A1 - Senze, A. A1 - Tkachenko, Viktoriya A1 - Witt, K. J. ED - Xu, Y. L. ED - Zhu, S. ED - Xia, Y. ED - Ni, Y.Q. ED - Law, S.S. ED - Yin, J. H. ED - Su, Z.Q. T1 - Detection of slipping soil areas with embedded tiny vertical sensing rods N2 - Critical soil zones where large areas along a shear joint might begin to slip should be recognized. In order to avoid damage, monitoring of such unstable zones is necessary. First, soil movements must be detected as early as possible, second, the amount of deformation should be estimated. Because geodetical methods do not provide information about deformation in the underground in different depths, the only way to come to information from possible shear zones is the installation of deformation measurement systems. A special installation method was developed to bring a long-gauge length measurement system into a borehole and transfer data of soil deformations into an installed sensing rod. The mostly vertically installed sensing rod has an outer diameter of 3 mm to 6 mm and contains several optical fibres. One fibre provides integral strain information along the whole length of the rod. To get this information, the phase difference between the fibre input and output is measured and the change of the total length of the fibre can be derived. This easy and cheap online sensing system delivers an early warning of soil deformations respectively possible slip as well as landslides. In case of warning, the second sensing system based on Fibre Bragg Grating sensors located close to the expected shear zone purposefully. It records resulting deformations in detail. In this study, three main objectives were achieved: a) development of tiny pultruded sensing rods with integrated optical sensor fibres, b) installation technology which enables the integration of the sensing rod during drilling and pile driving, and c) development of a stiff but elastic racking material to fix the rod in the soil and to transfer soil deformation into the stiffer sensing rod. These three aspects including the fibre optical measurement systems are described; results from Press Deformation Test (PDT) are presented. Test results of the fibre optical online system are compared and evaluated with the results of conventional inclinometer measurements as well as numerical modelling. An outlook for further possibilities of usage of this monitoring system is given. T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure CY - Hong Kong, China DA - 09.12.2013 KW - Structural health monitoring KW - Soil stability monitoring KW - Optical fibre strain-sensor KW - Geotechnical soil stability KW - Soil deformation modelling PY - 2013 SN - 978-962-367-768-4 SP - 1 EP - 9 AN - OPUS4-29915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Scholz, Philipp A1 - Kalbe, Ute A1 - Caliebe, W. A1 - Tayal, A. A1 - Vasala, S. J. A1 - Simon, Franz-Georg T1 - Speciation of antimony and vanadium in municipal solid waste incineration ashes analyzed by XANES spectroscopy N2 - The use of ashes from municipal solid waste incineration as secondary building materials is an important pillar for the circular economy in Germany. However, leaching of potential toxic elements from these materials must be at environmentally acceptable levels. Normally, a three-month ageing period immobilizes most hazardous heavy metals, but antimony (Sb) and vanadium (V) showed previously unusual leaching. In order to clarify the mechanisms, we analyzed the Sb and V species in various bottom and fly ashes from municipal waste incineration by XANES spectroscopy. Antimony oxidizes from Sb(+ III) species used as flame retardants in plastics to Sb(+ V) compounds during waste incineration. However, owing to the similarity of different Sb(+ V) compound in the Sb K- and L-edge XANES spectra, it was not possible to accurately identify an exact Sb(+ V) species. Moreover, V is mainly present as oxidation state + V compound in the analyzed ashes. However, the coarse and magnetic fraction of the bottom ashes contain larger amounts of V(+ III) and V(+ IV) compounds which might enter the waste incineration from vanadium carbide containing steel tools. Thus, Sb and V could be critical potential toxic elements in secondary building materials and long-term monitoring of the release should be taken into account in the future. KW - Müllverbrennung KW - XANES spectroscopy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599841 DO - https://doi.org/10.1007/s10163-024-01954-2 SN - 1438-4957 VL - 26 SP - 2152 EP - 72158 PB - Springer Science and Business Media LLC AN - OPUS4-59984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Stößer, R. A1 - Sebastian, S. A1 - Scholz, G. A1 - Willer, M. A1 - Jeschke, G. A1 - Schweiger, A. T1 - Pulse EPR Spectroscopy of Cu2+ - Doped Inorganic Glasses KW - EPR Spectroscopy KW - Inorganic glasses PY - 1999 SN - 0937-9347 SN - 1613-7507 IS - 16 SP - 507 EP - 528 PB - Springer CY - Wien AN - OPUS4-760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kothavale, S. A1 - Jadhav, A. G. A1 - Scholz, Norman A1 - Nirmalananthan-Budau, Nithiya A1 - Behnke, Thomas A1 - Resch-Genger, Ute A1 - Sekar, N. T1 - Corrigendum to "Deep red emitting triphenylamine based coumarin-rhodamine hybrids with large stokes shift and viscosity sensing: Synthesis, photophysical properties and DFT studies of their spirocyclic and open forms" [Dyes Pigments 137 (2017) 329-341] N2 - We designed and synthesized triphenylamine based and coumarin fused rhodamine hybrid dyes and characterized using 1H, 13C NMR and HR-LCMS analysis. Both the newly synthesized hybrid dyes were found to show red shifted absorption as well as emissions and large Stokes shift (40e68 nm) as compared to the small Stokes shift (25e30 nm) of reported dyes Rhodamine B and 101. Photophysical properties of these dyes were studied in different solvents and according to the solvents acidity or basicity they preferred to remain in their spirocyclic or open form in different ratio. We studied the spirocyclic as well as open form derivatives of these dyes for their viscosity sensitivity in three different mixture of solvents i.e. polar-protic [EtOH-PEG 400], polar-aprotic [toluene-PEG 400] and non-polaraprotic [toluene-paraffin]. They are found to show very high viscosity sensitivity in polar-protic mixture of solvents [EtOH-PEG 400] and hence concluded that both polarity as well as viscosity factor worked together for the higher emission enhancement rather than only viscosity factor. As these dyes showed very high viscosity sensitivity in their spirocyclic as well as open form, they can be utilized as viscosity sensors in visible as well as deep red region. We also correlated our experimental finding theoretically by using Density Functional theory computations. KW - Dye KW - Fluorescence KW - Synthesis KW - Quantum yield KW - Lifetime KW - Coumarin KW - Rhodamine KW - Probe KW - Viscosity PY - 2018 DO - https://doi.org/10.1016/j.dyepig.2017.06.021 SN - 0143-7208 SN - 1873-3743 N1 - Geburtsname von Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. - Birth name of Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. VL - 149 SP - 929 PB - Elsevier CY - Amsterdam AN - OPUS4-44038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fiedler Bremer, C. A1 - Scholz, R. A1 - Myslicki, S. A1 - Starke, P. A1 - Boller, C. A1 - Walther, F. A1 - Krause, Martin T1 - NDT-based characteriazation of timber and vulcanized fiber for civil infrastructure N2 - The paper addresses beech wood as well as vulcanized fiber and discusses the results obtained when using acoustic emission and thermography as non-destructive testing techniques along tensile and load increase fatigue tests to characterize the wooden material’s behavior under increasing fatigue loads to get enhanced information regarding the fatigue behavior of both materials. Reference is mainly made to the materials’ anisotropic and microstructural behavior and what implications this has with respect to the materials’ strength. The influence of moisture is discussed, as well as parameters that may deserve monitoring in the sense of structural health monitoring to be applied in timber structures in general. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Ermüdung KW - Belastungsversuch KW - Thermographie KW - ZfP KW - Timber PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346377 UR - https://www.ndt.net/?id=18419 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 11 PB - NDT.net CY - Kirchwald AN - OPUS4-34637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Amiri, Hesam A1 - Nikookhesal, Aidin A1 - Murugan, Divagar A1 - Scholz, Stefan A1 - Frentzen, Michael A1 - Cao, Yuan A1 - Nickl, Philip A1 - Radnik, Jörg A1 - Stockmann, Jörg M. A1 - Vu, Xuan-Thang A1 - Narayanan, Madaboosi S. A1 - Knoch, Joachim A1 - Ingebrandt, Sven A1 - Adeli, Mohsen A1 - Pachauri, Vivek T1 - High precision correlative analysis of dielectric behavior evolution and anisotropy in graphene oxide thin film as a function of thermal annealing parameters N2 - Graphene oxide (GO) and reduced graphene oxide (rGO) attract keen interest from different science and technology sectors owing to their tunable material characteristics dependent on C/O ratio. Thermal annealing in different gaseous environments serves as an effective approach to manipulate the C/O ratio in graphitic lattice, making it suitable for various electronic, optical and composites applications. Despite regular use of thermal annealing, systematic studies on dielectric properties evolution in GO against different annealing parameters remain elusive. This work reports on a reliable approach that adopts a joint Raman Spectroscopy, Mueller Matrix Spectroscopic Ellipsometry (MMSE) and high-precision electrical impedance spectroscopy (HP-EIS) framework for studying the evolution of dielectric behavior and anisotropies in GO. The experimental platform involved lithography-defined GO patterns connected to metal microelectrodes and glass passivation for protection from gaseous environments during annealing and measurements using Raman, MMSE and HP-EIS. The presented study delineates the effects of annealing parameters such as temperature, heating rate, and gaseous environment on GO permittivity. Novel findings include the discovery of a direct relationship between heating rate and dielectric properties, as well as determination of vertical limitation of MMSE for permittivity distribution characterization in GO, for the first time, to be around 8 nm. KW - Thermal annealing KW - Reduced graphene oxide KW - Thin films KW - 2D materials KW - Spectroscopic ellipsometry PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652428 DO - https://doi.org/10.1016/j.nwnano.2025.100130 SN - 2666-9781 VL - 11 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-65242 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -