TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana T1 - Exploring new materials for Green Intelligent Building how can our BAMline help N2 - With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. Synchrotron X-ray based methods enable unique tools to probe materials properties via e.g. X-ray spectroscopy and diffraction methods. The BAM plays a central role in this highly collaborative research. The BAMline, a real-life sample materials research beamline, at the Berlin Synchrotron BESSY-II, provides unique insights into materials’ electronic and chemical structure at different time and length scales1. This enables real-time optimization of material properties and performance for various applications, such as energy storage and conversion, catalysis, and deterioration resistance. T2 - DAfStb-Kolloquium CY - Berlin, Germany DA - 16.10.2024 KW - XAS KW - Time-resolved studies KW - Binding materials KW - Cements PY - 2024 AN - OPUS4-61616 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana T1 - Time resolved in situ monitoring of mechanochemical transformations by X-ray absorption spectroscopy (XAS) N2 - Mechanochemical reactions promise a new direction for environmentally benign preparation of materials, and has been dubbed by IUPAC as one of the 10 chemical innovations that will change our world. Despite this significant promise, very little is known about the mechanisms that drive mechanochemical transformations, posing significant barriers to realizing their full potential. To this end, there is growing need to follow mechanochemical reactions in situ and in real time. We here describe advances in the development and application of XAS methods to monitor material synthesis in real time under mechanochemical conditions. We demonstrate the generality of our approaches by describing mechanochemical syntheses of materials by both vibratory ball milling and by Resonant Acoustic Mixing (RAM), where a time resolution of 1 second is for a whole XAS spectrum was achieved. Moreover, we describe how spectroscopic methods can be coupled to diffraction-based approaches, thereby providing new dimensions in understanding mechanochemical synthesis. T2 - European Conference on X-ray Spectrometry 2022 CY - Bruges, Belgium DA - 27.06.2022 KW - XAS KW - Mechanochemictry KW - Time resolved KW - In situ PY - 2022 AN - OPUS4-56258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana T1 - Recent developments of X-ray absorption spectroscopy as analytical tool for biological and biomedical applications N2 - X-ray absorption spectroscopy (XAS), in its various modalities, has gained exponential attention and applicability in the field of biological and biomedical systems. Particularly in this field, challenges like low concentration of analyte or proneness to radiation damage have certainly settle the basis for further analytical developments, when using X-ray based methods. Low concentration calls for higher sensitivity—by increasing the detection limits (DL); while susceptibility for radiation damage requires shorter measurement times and/or cryogenic sample environment possibilities. This manuscript reviews the latest analytical possibilities that make XAS more and more adequate to investigate biological or biomedical systems in the last 5 years. KW - Biological & biomedical applications KW - TXRF-XAS KW - HERFD-XAS KW - RXES KW - Quick-XAS KW - Dispersive-XAS PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531206 DO - https://doi.org/10.1002/xrs.3254 SN - 0049-8246 VL - 51 IS - 3 SP - 1 EP - 10 PB - John Wiley & Sons Ltd AN - OPUS4-53120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de O. Primo, J. A1 - Horsth, D.F. A1 - de S. Correa, J. A1 - Das, A. A1 - Bittencourt, C. A1 - Umek, P. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Yusenko, Kirill A1 - Zanetta, C. A1 - Anaissi, F.J. T1 - Synthesis and Characterization of Ag/ZnO Nanoparticles for Bacteria Disinfection in Water N2 - n this study, two green synthesis routes were used for the synthesis of Ag/ZnO nanoparticles, using cassava starch as a simple and low-cost effective fuel and Aloe vera as a reducing and stabilizing agent. The Ag/ZnO nanoparticles were characterized and used for bacterial dis- infection of lake water contaminated with Escherichia coli (E. coli). Characterization indicated the formation of a face-centered cubic structure of metallic silver nanoparticles with no insertion of Ag into the ZnO hexagonal wurtzite structure. Physicochemical and bacteriological analyses described in “Standard Methods for the Examination of Water and Wastewater” were used to evaluate the efficiency of the treatment. In comparison to pure ZnO, the synthesized Ag/ZnO nanoparticles showed high efficiencies against Escherichia coli (E. coli) and general coliforms present in the lake water. These pathogens were absent after treatment using Ag/ZnO nanoparticles. The results indicate that Ag/ZnO nanoparticles synthesized via green chemistry are a promising candidate for the treatment of wastewaters contaminated by bacteria, due to their facile preparation, low-cost synthesis,and disinfection efficiency. KW - Synchrotron KW - BAMline PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-562440 DO - https://doi.org/10.3390/nano12101764 SN - 2079-4991 VL - 12 IS - 10 SP - 1 EP - 18 PB - MDPI CY - Basel AN - OPUS4-56244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Davison, Nathan A1 - Hemingway, Jack M. A1 - Wills, Corinne A1 - Stolar, Tomislav A1 - Waddell, Paul G. A1 - Dixon, Casey M. A1 - Barron, Luke A1 - Dawson, James A. A1 - Lu, Erli T1 - Mechanochemical Synthesis of a Sodium Anion Complex [Na+(2,2,2-cryptand)Na] and Studies of Its Reactivity: Two-Electron and One-Electron Reductions N2 - Group 1 metal molecular chemistry is dominated by a +1 oxidation state, while a 0 oxidation state is widespread in the metals. A more exotic, yet still available, oxidation state of group 1 metal is −1, i.e., alkalide. Reported as early as the 1970s, the alkalides appear in every modern inorganic chemistry textbook as an iconic chemical curiosity, yet their reactivity remains unexplored. This is due to their synthetic hurdles. In this work, we report the first facile synthesis of the archetypical alkalide complex, [Na+(2,2,2-cryptand)Na–], which allows us to unveil a versatile reactivity profile of this once exotic species. KW - Mechanochemistry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608632 DO - https://doi.org/10.1021/acs.inorgchem.4c02914 VL - 63 IS - 32 SP - 15247 EP - 15258 PB - American Chemical Society (ACS) AN - OPUS4-60863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Das, Prasenjit A1 - Chakraborty, Gouri A1 - Yang, Jin A1 - Roeser, Jérôme A1 - Küçükkeçeci, Hüseyin A1 - Nguyen, Anh Dung A1 - Schwarze, Michael A1 - Gabriel, Jose A1 - Penschke, Christopher A1 - Du, Shengjun A1 - Weigelt, Vincent A1 - Khalil, Islam E. A1 - Schmidt, Johannes A1 - Saalfrank, Peter A1 - Oschatz, Martin A1 - Rabeah, Jabor A1 - Schomäcker, Reinhard A1 - Emmerling, Franziska A1 - Thomas, Arne T1 - The Effect of Pore Functionality in Multicomponent Covalent Organic Frameworks on Stable Long‐Term Photocatalytic H2 Production N2 - AbstractIn nature, organic molecules play a vital role in light harvesting and photosynthesis. However, regarding artificial water splitting, the research focus is primarily on inorganic semiconductors. Although organic photocatalysts have high structural variability, they tend to exhibit lower quantum efficiencies for water splitting than their inorganic counterparts. Multicomponent reactions (MCRs) offer an attractive route to introduce different functional units into covalent organic frameworks (COFs) and enable semiconducting properties and high chemical stability, creating promising materials for long‐term photocatalytic applications, such as H2 production. Herein, five highly crystalline donor‐acceptor based, 4‐substituted quinoline‐linked MCR‐COFs are presented that are prepared via the three‐component Povarov reaction. The pore functionality is varied by applying different vinyl derivatives (e.g., styrene, 2‐vinyl pyridine, 4‐vinylpyridine, 4‐vinyl imidazole, 2,3,4,5,6‐pentafluorostyrene), which has a strong influence on the obtained photocatalytic activity. Especially an imidazole‐functionalized COF displays promising photocatalytic performance due to its high surface area, crystallinity, and wettability. These properties enable it to maintain its photocatalytic activity even in a membrane support. Furthermore, such MCR‐COFs display dramatically enhanced (photo)chemical stability even after long‐term solar light irradiation and exhibit a high and steady H2 evolution for at least 15 days. KW - Sstability KW - Covalent organic frameworks KW - Pore functionality KW - Long-term H2 production KW - Multicomponent reactions PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639787 DO - https://doi.org/10.1002/aenm.202501193 SN - 1614-6832 SP - 1 EP - 10 PB - Wiley VHC-Verlag AN - OPUS4-63978 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Das, Prasenjit A1 - Chakraborty, Gouri A1 - Friese, Nico A1 - Roeser, Jérôme A1 - Prinz, Carsten A1 - Emmerling, Franziska A1 - Schmidt, Johannes A1 - Thomas, Arne T1 - Heteropolyaromatic Covalent Organic Frameworks via One-Pot Multicomponent Reactions N2 - Multicomponent reactions (MCRs) offer a platform to create different chemical structures and linkages for highly stable covalent organic frameworks (COFs). As an illustrative example, the multicomponent Povarov reaction generates 2,4-phenylquinoline from aldehydes and amines in the presence of electron-rich alkenes. In this study, we introduce a new domino reaction to generate unprecedented 2,3-phenylquinoline COFs in the presence of epoxystyrene. This work thus presents, for the first time, structural isomeric COFs produced by multicomponent domino and Povarov reactions. Furthermore, 2,3-phenylquinolines can undergo a Scholl reaction to form extended aromatic linkages. With this approach, we synthesize two thermally and chemically stable MCR-COFs and two heteropolyaromatic COFs using both domino and in situ domino and Scholl reactions. The structure and properties of these COFs are compared with the corresponding 2,4-phenylquinoline-linked COF and imine-COF, and their activity toward benzene and cyclohexane sorption and separation is investigated. The position of the pendant phenyl groups within the COF pore plays a crucial role in facilitating the industrially important sorption and separation of benzene over cyclohexane. This study opens a new avenue to construct heteropolyaromatic COFs via MCR reactions. KW - COF PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604038 DO - https://doi.org/10.1021/jacs.4c02551 SP - 1 EP - 9 PB - American Chemical Society (ACS) AN - OPUS4-60403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Das, P. A1 - Chakraborty, Gouri A1 - Roeser, J. A1 - Vogl, S. A1 - Rabeah, J. A1 - Thomas, A. T1 - Integrating Bifunctionality and Chemical Stability in Covalent Organic Frameworks via One-Pot Multicomponent Reactions for Solar-Driven H2O2 Production N2 - Multicomponent reactions (MCRs) can be used to introduce different functionalities into highly stable covalent organic frameworks (COFs). In this work, the irreversible three-component Doebner reaction is utilized to synthesize four chemically stable quinoline-4-carboxylic acid DMCR-COFs (DMCR-1−3 and DMCR-1NH) equipped with an acid−base bifunctionality. These DMCR-COFs show superior photocatalytic H2O2 evolution (one of the most important industrial oxidants) compared to the imine COF analogue (Imine-1). This is achieved with sacrificial oxidants but also in pure water and under an oxygen or air atmosphere. Furthermore, the DMCR-COFs show high photostability, durability, and recyclability. MCR-COFs thus provide a viable materials’ platform for solar to chemical energy conversion. KW - Reactions KW - Bifunctionality KW - Postsynthetic modification KW - Multicomponent PY - 2022 DO - https://doi.org/10.1021/jacs.2c11454 SN - 0002-7863 VL - 145 IS - 5 SP - 2975 EP - 2984 PB - ACS Publications AN - OPUS4-56922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Das, Chayanika A1 - Kastania, Eleni A1 - Witt, Julia A1 - Özcan Sandikcioglu, Özlem T1 - Corrosion protection properties of poly(4-vinyl pyridine) containing multilayer polymeric coatings on magnesium alloy AZ31 N2 - The aim of this study is to develop polymeric thin films for corrosion protection of magnesium alloy AZ31. As polymer matrix, poly(4-vinyl pyridine) (P4VP) is selected due to its semiconducting properties and protonic conductivity. Polyacrylic acid is tested as crosslinking layers to improve interfacial adhesion. The macroscopic corrosion properties of the multilayer coatings are investigated by means of electrochemical methods, such as linear sweep voltammetry and electrochemical impedance spectroscopy (EIS), in corrosive media simulating technical and biomedical applications. It is demonstrated that thin multilayer coatings can suppress the corrosion rates of magnesium alloys. To our best knowledge, this is the first demonstration of the use of P4VP as a conducting polymer film with protonic conductivity for corrosion protection of magnesium alloys. KW - Multilayercoatings KW - AZ31 KW - Corrosion protection KW - Intrinsically conducting polymers KW - Magnesium alloys PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551799 DO - https://doi.org/10.1002/maco.202112708 SN - 0947-5117 VL - 73 IS - 3 SP - 427 EP - 435 PB - Wiley VHC-Verlag AN - OPUS4-55179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darvishi Kamachali, Reza A1 - Wallis, Theophilus A1 - Ikeda, Yuki A1 - Saikia, U. A1 - Ahmadian, A. A1 - Liebscher, C. A1 - Hickel, Tilmann A1 - Maaß, Robert T1 - Giant segregation transition as origin of liquid metal embrittlement in the Fe-Zn system N2 - A giant Zn segregation transition is revealed using CALPHAD-integrated density-based modeling of segregation into Fe grain boundaries (GBs). The results show that above a threshold of only a few atomic percent Zn in the alloy, a substantial amount of up to 60 at.% Zn can segregate to the GB. We found that the amount of segregation abruptly increases with decreasing temperature, while the Zn content in the alloy required for triggering the segregation transition decreases. Direct evidence of the Zn segregation transition is obtained using high-resolution scanning transmission electron microscopy. Base on the model, we trace the origin of the segregation transition back to the low cohesive energy of Zn and a miscibility gap in Fe-Zn GB, arising from the magnetic ordering effect, which is confirmed by ab-initio calculations. We also show that the massive Zn segregation resulting from the segregation transition greatly assists with liquid wetting and reduces the work of separation along the GB. The current predictions suggest that control over Zn segregation, by both alloy design and optimizing the galvanization and welding processes, may offer preventive strategies against liquid metal embrittlement. KW - CALPHAD KW - Microstructure Design KW - Grain boundary engineering KW - Steels KW - Density-based Model KW - Segregation Engineering PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-584292 DO - https://doi.org/10.1016/j.scriptamat.2023.115758 SN - 1359-6462 SN - 1872-8456 VL - 238 SP - 1 EP - 5 PB - Elsevier CY - Amsterdam AN - OPUS4-58429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -