TY - JOUR A1 - Nirmalananthan-Budau, Nithiya A1 - Budau, J. H. A1 - Moldenhauer, Daniel A1 - Hermann, G. A1 - Kraus, Werner A1 - Hoffmann, Katrin A1 - Paulus, Beate A1 - Resch-Genger, Ute T1 - Substitution pattern controlled aggregation-induced emission in donor-acceptor-donor dyes with one and two propeller-like triphenylamine donors N2 - We present a comparative study of the spectroscopic properties of the donor–acceptor–donor substituted dyes triphenylamine-allylidenemalononitrile-julolidine (TMJ) and triphenylamine-allylidenemalononitriletriphenylamine (TMT), bearing one and two propeller-like triphenylamine donor moieties, in solvents of varying polarity and viscosity and in the aggregated and solid state. Our results reveal control of the aggregation-induced spectroscopic changes and the packing motifs of the dye molecules in the solid state by the chemical nature and structure of the second nitrogen-containing donor, i.e., a planar and a rigid julolidine or a twisted triphenyl group. Assuming that the TMT and TMJ aggregates show a comparable arrangement of the molecules to the respective crystals, these different molecular interactions in the solid state are responsible for aggregation induced emission (AIE) in the case of TMT and its absence for TMJ. Moreover, a versatile strategy for the fluorescence enhancement of only weakly emissive AIE dyes is shown, turning these dyes into bright nanoscale fluorescent reporters by using them as stains for preformed polymer particles. KW - Nano KW - Nanoparticle KW - Photoluminescence KW - Fluorescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Dye KW - Enhancement KW - Particle KW - Polarity KW - AIE KW - Aggregation KW - Aggregation-induced emission KW - Solid state emission PY - 2020 DO - https://doi.org/10.1039/d0cp00413h VL - 22 IS - 25 SP - 14142 EP - 14154 AN - OPUS4-50967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krappe, Alexander R. A1 - Mayer, Jacob C. A1 - Zhang, Wuai A1 - Filla, Lina M. A1 - Ligorio, Giovanni A1 - Hermerschmidt, Felix A1 - Eitelhuber, Larissa S. A1 - Güttler, Arne A1 - Weber, Manuela A1 - Paulus, Beate A1 - Resch-Genger, Ute A1 - List-Kratochvil, Emil J.W. A1 - Eigler, Siegfried T1 - Highly Emissive Hexa-peri-benzocoronene-fluoranthene Hybrid as Easily Processable and Stable OLED Material N2 - We report the synthesis of a fluorescent polycyclic aromatic hydrocarbon dye with a “symmetry-broken” core, derived from the related hexa-peri-benzocoronene (HBC) core with fluoranthene subunit. The fluorophore is composed of a pure Carbon skeleton without heteroatoms and exhibits remarkable photo luminescence properties with a photoluminescence Quantum yield (PLQY) of up to 67% in toluene, exceeding that of theparent HBC by a factor of 30. The single crystal X-ray structure reveals the distorted polycyclic aromatic hydrocarbon structure, which is responsible for the optoelectronic properties, as supported by density functional theory calculations. We show that the new fluorescent dye can be readily used for the fabrication of organic light-emitting diodes (OLED) without extensive optimization, whereby solubility in a variety of solvents and successful film formation are decisive. KW - Quantum Yield KW - OLED KW - Fluorescence KW - Synthesis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631298 DO - https://doi.org/10.1002/chem.202500742 SN - 1521-3765 SP - 1 EP - 7 PB - John Wiley & Sons, Inc AN - OPUS4-63129 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senges, Gene A1 - de Oliveira Guilherme Buzanich, Ana A1 - Lindič, Tilen A1 - Gully, Tyler A. A1 - Winter, Marlon A1 - Radtke, Martin A1 - Röder, Bettina A1 - Steinhauer, Simon A1 - Paulus, Beate A1 - Emmerling, Franziska A1 - Riedel, Sebastian T1 - Unravelling highly oxidized nickel centers in the anodic black film formed during the Simons process by in situ X-ray absorption near edge structure spectroscopy N2 - The electrofluorination after Simons has been used for the last century to produce everyday life materials. An in situ XANES investigation of the controversially debated black film apparent in the Simons process revealed high-valent nickel centers. KW - Synchrotron KW - BAMline KW - XANES PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608366 DO - https://doi.org/10.1039/d3sc06081k SN - 2041-6520 VL - 15 IS - 12 SP - 4504 EP - 4509 PB - Royal Society of Chemistry (RSC) AN - OPUS4-60836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gomes, Bruna F. A1 - Prokop, Martin A1 - Bystron, Tomas A1 - Loukrakpam, Rameshwori A1 - Melke, Julia A1 - Lobo, Carlos M. S. A1 - Fink, Michael A1 - Zhu, Mengshu A1 - Voloshina, Elena A1 - Kutter, Maximilian A1 - Hoffmann, Hendrik A1 - Yusenko, Kirill V. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Röder, Bettina A1 - Bouzek, Karel A1 - Paulus, Beate A1 - Roth, Christina T1 - Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using In Situ X-ray Absorption Spectroscopy N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalystwith H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate Proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR). The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition. KW - H3PO4 life cycle KW - XAS KW - In situ coupling KW - High-temperature fuel cells KW - H3PO3, KW - Δμ XANES PY - 2022 DO - https://doi.org/10.1021/acscatal.2c02630 SN - 2155-5435 VL - 12 IS - 18 SP - 11472 EP - 11484 PB - American Chemical Society (ACS) AN - OPUS4-64733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fornacon-Wood, Christoph A1 - Stühler, Merlin R. A1 - Millanvois, Alexandre A1 - Steiner, Luca A1 - Weimann, Christiane A1 - Silbernagl, Dorothee A1 - Sturm, Heinz A1 - Paulus, Beate A1 - Plajer, Alex J. T1 - Fluoride recovery in degradable fluorinated polyesters N2 - We report a new class of degradable fluorinated polymers through the copolymerization of tetrafluorophthalic anhydride and propylene oxide or trifluoropropylene oxide which show up to 20 times quicker degradation than the non-fluorinated equivalents and allow for fluoride recovery. KW - Fluoropolymers KW - Recycling KW - PFAS KW - AFM force distance curves KW - AFM plastic deformation KW - AFM friction analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-606768 DO - https://doi.org/10.1039/d4cc02513j VL - 60 SP - 7479 EP - 7482 PB - Royal Society of Chemistry AN - OPUS4-60676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -