TY - CONF A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagl, Dorothee A1 - Elert, Anna Maria T1 - Combination of advanced atomic force microscopy methods to investigate mechanical and chemical interphases in epoxy-boehmite nanocomposites N2 - Formation of interphases between inorganic nanofillers and thermoplastic matrices are usually correlated to short-range interactions which does not exceed more than tens of nanometers away from the surface of the filler. Nevertheless, in nanocomposites with thermosetting matrices, the effect of nanofillers on the properties of the matrix is not limited to the immediate vicinities, but a long-range property alteration of the bulk polymer may be observed. The interaction between nanofillers and the polymer can disturb the curing reaction and alters the chemical, physical and mechanical properties of the polymer network in the matrix phase. In our studies, we aim to investigate short and long-range interphases of a nanocomposite system consisting of a thermosetting matrix (DGEBA) filled with an inorganic nanoparticle (boehmite). For this purpose, a combination of atomic force microscopy (AFM)-based approaches is implemented. Scanning kelvin probe microscopy (SKPM) was used to map the compositional contrast and the interphase with different electrical properties than the bulk. The mechanical properties of the interphase were probed by high resolution intermodulation AFM. (ImAFM). Furthermore, infrared spectroscopy AFM (AFM-IR) is used to investigate the chemical structure of the matrix at different distances from the nanoparticle. SKPM and (AFM-IR) measurements both show a long-range (to 10 µm) effect of boehmite on the chemical structure and surface potential of the bulk epoxy, respectively, whereas ImAFM force measurements reveals a short-range mechanical interphase between the filler and the matrix. The AFM-IR demonstrated the existence of unreacted anhydride hardener at the interphase. This indicates the preferential absorption of anhydride on the surface of boehmite. The consequence of such a selective interaction between the inorganic filler and the epoxy components is disturbance of the epoxy-hardener stoichiometric ratio, the curing mechanism. and the alteration of bulk properties of the matrix. T2 - EUROMAT CY - Stockholm, Sweden DA - 01.09.2019 KW - AFM KW - SKPM KW - AFM-IR KW - ImAFM KW - Boehmite PY - 2019 AN - OPUS4-50693 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagl, Dorothee A1 - Sturm, Heinz T1 - Mechanical and chemical alteration of polymer matrix induced by nanoparticles in epoxy-boehmite nanocomposites N2 - Inorganic nanoparticles are used to improve the performance of epoxy as the matrix phase in fiber-reinforced composites used for aerospace applications. The effectiveness of nanofillers on property enhancement of thermosetting polymers depends on many factors including the interaction between the functional groups of nanofillers and the polymer reactants. In the current work, we study the effect of boehmite nanoparticles (BNPs) on properties of anhydride-cured bisphenol-A-diglycidyl ether (DGEBA). Dynamic mechanical thermal analysis (DMTA) and a high-resolution force measurement approach called intermodulation atomic force microscopy (ImAFM) were carried out to investigate the thermomechanical and nanomechanical properties of this material, respectively. It was found that BNPs lead to decrease of glass transition temperature (Tg) and crosslink density of the polymer network meanwhile significantly enhancing the Young’s modulus. Besides formation of a soft interphase near the particles, significant changes in local stiffness of polymer matrix far from the interphase was observed with ImAFM. Thus, boehmite induces long-range chemical alteration on the matrix. This effect has a higher impact on overall composite properties compared to the formation of interphase which is only a short-range effect. The local chemical evaluations on the soft interphase using an infrared-AFM method (NanoIR) revealed the accumulation of anhydride hardener near the boehmite interface. Based on these observations the effect of boehmite on the curing of epoxy is hypothesized to be governed by the strong interaction between boehmite and the anhydride. This interaction causes changes the ratio of reactants in the epoxy mixture and hence alteration of curing pathway and the network architecture. In future studies we examine this hypothesis by measuring the thermomechanical properties of cured epoxies in which the epoxy-hardener ratio is systematically altered and further comparing to those properties of nanocomposites shown in the current study. T2 - HYMA 6th International Conference on Multifunctional, Hybrid and Nanomaterials CY - Sitges, Spain DA - 11.03.2019 KW - Nanomechanics KW - Polymer nanocomposites KW - Boehmite KW - AFM KW - Epoxy PY - 2019 AN - OPUS4-50692 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Smith, A. J. A1 - Snow, T. A1 - Shebanova, O. A1 - Sutter, J. P. A1 - Hermida-Merino, D. A1 - Smales, Glen Jacob A1 - Terrill, N. J. A1 - Thünemann, Andreas A1 - Bras, W. T1 - Extending SAXS instrument ranges through addition of a portable, inexpensive USAXS module T2 - arxiv.org N2 - Ultra-SAXS can enhance the capabilities of existing SAXS/WAXS beamlines and laboratory instruments. A compact Ultra-SAXS module has been developed, which extends the measurable q-range with 0:0015 < q 1/nm) < 0:2, allowing structural dimensions between 30 < D(nm) < 4000 to be probed in addition to the range covered by a high-end SAXS/WAXS instrument. By shifting the module components in and out on their respective motor stages, SAXS/WAXS measurements can be easily and rapidly interleaved with USAXS measurements. KW - Small-angle scattering PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504867 UR - https://arxiv.org/abs/1904.00080 SN - 2331-8422 SP - 1 EP - 25 PB - Cornell University CY - Ithaca, NY AN - OPUS4-50486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Markötter, Henning A1 - Gollwitzer, Christian A1 - Scholz, Philipp A1 - Ulbricht, Alexander A1 - Joshi, Yogita A1 - Weidner, Steffen T1 - Synchrotron based absorption edge tomography for the analysis of 3D printed polymer embedded MOF N2 - Absorption edge tomography, also known as differential tomography at absorption edges, is a method which exploits the sudden change of the attenuation coefficient, when the photon energy crosses the absorption edge of an element. Synchrotron radiation is the best source for absorption edge tomography, because of its small bandwidth, high intensity and easily adjustable photon energy. The synchrotron beamline BAMline at the synchrotron radiation facility BESSY II in Berlin, which is operated by the Bundesanstalt für Materialforschung und -prüfung (BAM), provides a monochromatized beam in a photon energy range from 5 keV up to 80 keV with a bandwidth of 2%, when the double multilayer monochromator is used. Together with the microtomography setup, this enables differential tomography with submicron resolution at the K edge of the elements from chromium up to the lanthanides, and up to uranium, when the L edges are used as well. In this work, metal organic frameworks (MOFs) embedded in polymer are characterized using differential tomography. MOFs are microporous structures of metal ions, coordinated by organic linker molecules, that can be used in a broad field of applications, especially in gas storage and catalysis. In this work, polymer embedded MOFs were extruded into filaments, which were subsequently used for 3d-printing to profit from the specific properties of the MOFs in polymeric materials combined with the arbitrary shapes provided by 3d-printing. For the extrusion, different polymer classes like ABS, polyester- and polyetherurethanes, as well as different MOFs (ZIF-8, ZIF-67, HKUST-1) were used to create MOF containing filaments with a nominal diameter of 3.0 mm. Differential tomography at the edges of the Zn, Co, and Cu was then used to find the distribution of the corresponding MOF in the filament and to analyze the shape of the inclusions. T2 - Beamline Jockey Workshop CY - Abingdon, Oxfordshire, UK DA - 19.02.2020 KW - Additive manufacturing KW - Absorption edge tomography KW - Metal organic framework KW - Synchrotron CT PY - 2019 AN - OPUS4-50350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Beck, Uwe A1 - Hielscher, Stefan A1 - Lerche, D. T1 - Abschlussbericht zum BMWi - MNPQ – Verbundprojekt QUO VADIS PLUS (Mehr-Proben-Festigkeitsprüfung zur Qualitätssicherung in der Materialtechnik und Validierung der Zentrifugentechnologie bei Druck- bzw. Zugbeanspruchung) N2 - Im Fokus des Vorhabens steht das mit dem Innovationspreis Berlin-Brandenburg 2012 ausgezeichnete Mehr-Proben-Prüfverfahren zur Festigkeitsprüfung unter Verwendung einer analytischen Zentrifuge mit dem Ziel des Einsatzes in der Qualitätssicherung. Nachdem im MNPQ-Projekt QUO VADIS die grundsätzliche Anwendbarkeit der Zentrifugentechnologie auf Beanspruchungen auf Zug (Kleb-, Haft- und Verbundfestigkeit) nachgewiesen worden war, wurden im Vorhaben QUO VADIS PLUS folgende erweiterte Prüfszenarien und technische Weiterentwicklungen etabliert: 1. Beanspruchung auf Druck (Härte von Materialien, Kompressibilität von Schäumen, Kompaktierbarkeit von Pulvern), 2. Erweiterung der Beanspruchung auf Zug (Kombination von Normal- und Lateralkräften), 3. Erweiterung auf die Bewertung plasto-elastischenn Materialverhaltens, 4. Vermeidung von Schockwellen im Hochlastbereich KW - Analytische Zentrifuge KW - Mehr-Proben-Prüfverfahren KW - Härte KW - Kompressibilität KW - Kompaktierbarkeit KW - Haftfestigkeit KW - Klebfestigkeit KW - Verbundfestigkeit PY - 2019 N1 - Das Dokument unterliegt der Vertraulichkeit und kann nicht zugänglich gemacht werden Projektlaufzeit: 01.05.2015 bis 28.02.2019 The document is subject to confidentiality restrictions and cannot be made accessible Project runtime: 01.05.2015 to 28.02.2019 SP - 1 EP - 20 AN - OPUS4-50406 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulka, M. W. A1 - Donskyi, Ievgen A1 - Wurzler, Nina A1 - Salz, D. A1 - Özcan Sandikcioglu, Özlem A1 - Unger, Wolfgang A1 - Haag, R. T1 - Mussel-Inspired Multivalent Linear Polyglycerol Coatings Outperform Monovalent Polyethylene Glycol Coatings in Antifouling Surface Properties JF - ACS Applied Biomaterials N2 - Biofouling constitutes a major challenge in the application of biosensors and biomedical implants, as well as for (food) packaging and marine equipment. In this work, an antifouling surface coating based on the combination of mussel-inspired dendritic polyglycerol (MI-dPG) and an amine-functionalized block copolymer of linear polyglycerol (lPG−b−OA11, OA = oligo-amine) was developed. The coating was compared to a MI-dPG surface which was postfunctionalized with commercially available amine-terminated Polyethylene glycol (HO−PEG−NH2) of similar molecular weight. In the current work, These coatings were compared in their chemical stability, protein fouling characteristics, and cell fouling characteristics. The lPG−b−OA11-functionalized coating showed high chemical stability in both phosphate buffered saline (PBS) and sodium dodecyl sulfate (SDS) solutions and reduced the adhesion of fibrinogen from human plasma with 99% and the adhesion of human serum albumin with 96%, in comparison to the bare titanium dioxide substrate. Furthermore, the Proliferation of human umbilical vein endothelial cells (HUVECs) was reduced with 85% when the lPG−b−OA11 system was compared to bare titanium dioxide. Additionally, a reduction of 94% was observed when the lPG−b−OA11 system was compared to tissue culture polystyrene. KW - Antifouling surface coatings KW - Human umbilical cell adhesion KW - Linear polyglycerol KW - Polyethylene glycol KW - Mussel-inspired adhesives PY - 2019 DO - https://doi.org/10.1021/acsabm.9b00786 VL - 2 IS - 12 SP - 5749 EP - 5759 PB - ACS AN - OPUS4-50342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rietz, U. A1 - Küchler, S. A1 - Lerche, D. A1 - Lange, Thorid A1 - Hielscher, Stefan A1 - Beck, Uwe T1 - Zentrifugalkraftbasierte Mehrprobenprüfung in einer analytischen Zentrifuge zur Bestimmung von Kleb- und Haftfestigkeiten: Metallische Referenzverbunde, Plasmaaktivierung von Polymeren, Schichthaftung auf GFK, Wirkung von Primern T2 - Atmosphärische Plasmen, Anwendungen - Entwicklungen - Anlagen N2 - Das Fügeverfahren Kleben bietet viele Vorteile wie z.B. das Verbinden schwieriger Materialklassen, geringe thermische Belastung (Strukturveränderung/-schwächung) der Fügepartner und eine Lastverteilung über den gesamten Fügebereich. Die Auswahl an verfügbaren Klebstoffen und Vorbehandlungsoptionen ist dabei ebenfalls vielfältig. Einige Polymere weisen darüber hinaus Eigenschaften auf, die eine Herstellung von festen und dauerhaft beanspruchbaren Klebverbindungen erschweren. Mittels Oberflächenbehandlung, z.B. durch Plasmafeinreinigung bzw. –aktivierung, können die Grenzflächern solcher Polymere - bezogen auf die Eignung als Fügeteilpartner – optimiert werden. Schnelle Prüfverfahren zur Ermittlung von Verbundeigenschaften sind somit erforderlich. Das Messprinzip Centrifugal Adhesion Testing Technologie verwendet die radial gerichtete Zentrifugalkraft als Belastungsgröße des zu testenden Verbunds, die durch Variation der Drehzahl gesteuert wird. Bei Erreichen der kritischen Beanspruchung trennt sich ein aufgeklebter Prüfstempel vom Substrat. Zeitgleich wird ein positionsbezogenes IR-Signal aus dem drehenden Rotor an das Basisgerät gesendet und zusammen mit der Drehzahl an die PC-Software übertragen. Für jede Probe wird die Bruchkraft berechnet und in Echtzeit angezeigt. Der Adhesion Analyser LUMiFrac® untersucht bis zu acht Prüfkörper unter identischen Bedingungen. Das neue Messprinzip erfüllt die Anforderungen von DIN EN 15870, DIN EN 14869-2, ISO 4624 sowie DIN EN 13144. Die Multiprobentestung ermöglicht schnelle Charakterisierungen von Klebverbindungen. So kann der Effekt einer Plasmabehandlung von Bauteilen auf die Verbundfestigkeit zeitsparend bestimmt werden. Die gezielte Veränderung unterschiedlicher Plasma-Parameter, wie beispielsweise, die Plasmazusammensetzung, der Abstand vom Plasmabrenner zur Oberfläche oder die Verweildauer unter dem Brenner, beeinflußt die Festigkeit des Klebsystems und ist dem LUMiFrac direkt quantifizierbar. Neben der Festigkeitsbestimmung von Klebverbindungen ist die Haftung von Schichtsystemen ein wichtiger Anwendungsbereich. Ergebnisse für Zug- und Scherbeanspruchung, realisiert mit unterschiedlichen Prüfkörper-Geometrien, werden vorgestellt. Ferner werden verschiedene festigkeitsbeeinflussende Faktoren, wie Prüfgeschwindigkeit oder Substratverformung bei Beanspruchung untersucht T2 - 35. Workshop des ak-adp CY - Nuremberg, Germany DA - 20.11.2019 KW - Adhäsion KW - Mehrprobenprüfung KW - Analytische Zentrifuge KW - Kleb- und Haftfestigkeit PY - 2019 SN - 978-3-00-063646-2 SP - 100 EP - 109 AN - OPUS4-50149 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Almalla, Ahed A1 - Fernandes Jamar, Marina A1 - Stepien, Daniel T1 - Untersuchung lokaler Korrosionsprozesse mittels kombinierter elektrochemischer und mikroskopischer Methoden N2 - Aktuelle Forschungsergebnisse - Korrosionseigenschaften von AA 2024-T3 und AM-316 unter gekoppelter korrosiv/mechanischer Beanspruchung. T2 - MPIE Düsseldorf, Sitzung der GfKORR Arbeitskreise Grundlagen und Simulation und Korrosionsuntersuchung und überwachung CY - Dusseldorf, Germany DA - 20.11.2019 KW - Corrosion KW - Atomic Force Microscopy (AFM) KW - Coupled corrosive/mechanical load PY - 2019 AN - OPUS4-50296 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Schenderlein, Matthias A1 - Hampel, Marco A1 - Almalla, Ahed T1 - Coupled electrochemical, microscopic and spectroscopic techniques for the analysis of local corrosion and mic processes N2 - Summary of the research topics of the division 6.2 and recent results T2 - HZDR-IRE Institutscolloquium CY - Dresden, Germany DA - 24.09.2019 KW - MIC KW - Localised corrosion KW - Corrosion monitoring KW - Biofilmbildung KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Fernandes Jamar, Marina A1 - Stepien, Daniel T1 - In situ atomic force microscopy (AFM) analysis of materials under combined corrosive and mechanical load N2 - In service, most materials are operated under simultaneous corrosive and mechanical load and there are very few methods capable for testing material degradation under these conditions, especially when it comes to high resolution analysis. For this purpose, in this work, a tensile module capable of uniaxial stretching and compression with up to 5 kN force was integrated into an AFM stage. The elimination of the need for sample unmounting and remounting and the resulting possibility of keeping the sample under constant mechanical load during AFM measurements not only enables a precise positioning of the area of interest but also allows for the analysis of processes in the elastic deformation regime. This methodology was demonstrated for two case studies. Scanning Kelvin Probe Force Microscopy (SKPFM) was used as the main tool to characterize the deformation behavior. Moreover, a flexible electrochemical measurement cell was used to enable electrochemical analysis by means of electrochemical impedance spectroscopy (EIS) and Linear Sweep Voltammetry (LSV) during AFM measurements at different levels of strain. The in situ AFM results are complemented by microstructure analysis by means of electron backscatter diffraction (EBSD). In the first case study, the deformation induced delamination of a thin organic coating on AA2024 T3 aluminium alloy was investigated as a function of alloy surface treatment. The formation of cracks in the insulating passive film enabled an early detection of deformation processes by means of SKPFM. The second case study focused on the comparison of corrosion and deformation behavior of conventional and additively manufactured 316 stainless steels. In comparison to the conventional 316 stainless steel, the effect of processing was clearly detectable on the additively manufactured material as zones of inhomogeneous potential, which also affected the initiation of local corrosion processes. The contribution will provide detailed information on the new AFM setup and summarize our results from both case studies. T2 - EuroCorr2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Coupled corrosive and mechanial load KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50294 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -