TY - JOUR A1 - Tschiersch, Anja A1 - Banerji, Amitabh A1 - Remus, Ludger T1 - Thymolblau – schulische Synthese & AR-gestützte Lernmaterialien JF - Chemie konkret : CHEMKON ; Forum für Unterricht und Didaktik N2 - This article presents the synthesis of thymol blue as a student experiment together with suitable augmented reality (AR) learning materials. In addition, the theoretical background on the synthesis of thymol blue and its pH-dependent structure-property relationship is discussed with regards to recent findings. Furthermore, experiences with the experiment in school and university lab-trainings as well as in teacher trainings are reported. N2 - In diesem Artikel werden die Synthese von Thymolblau als Schülerexperiment und passende Augmented-Reality (AR)-gestützte Lernmaterialien vorgestellt. Zudem wird der Kenntnisstand zur Synthese von Thymolblau sowie dessen pH-abhängige Struktur-Eigenschafts-Beziehung vor dem Hintergrund neuerer Erkenntnisse diskutiert und es wird über Erfahrungen mit dem Einsatz des Experimentes in der schulischen und universitären Praxis und im Rahmen von Fortbildungen berichtet. T2 - Thymol blue - hands-on synthesis & AR-based learning materials KW - thymol blue KW - indicator KW - school experiment KW - augmented reality KW - synthesis KW - Thymolblau KW - Indikator KW - Schulversuch KW - Synthese Y1 - 2021 U6 - https://doi.org/10.1002/ckon.202100011 SN - 0944-5846 SN - 1521-3730 VL - 28 IS - 6 SP - 266 EP - 269 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Banerji, Amitabh A1 - Thyssen, Christoph A1 - Pampel, Barbara A1 - Huwer, Johannes T1 - Naturwissenschaftsunterricht und Informatik BT - bringt zusammen, was zusammen gehört?! BT - bringing together, what belongs together?! JF - Chemie konkret : CHEMKON ; Forum für Unterricht und Didaktik N2 - Computer literacy plays an increasingly important role in the education of 21st-century society. For chemistry' education. this results in two aspects: On the one hand. informatics education concepts can help to promote chemistry- and science-specific ways of thinking and working. On the other hand, chemistry education can contribute to information education. This paper addresses both aspects and tries to point out the Mutual benefits of informatics education and science education with regards to chemistry lessons. N2 - Informatische Bildung spielt eine immer zentralere Rolle in der Bildung einer Gesellschaft des 21. Jahrhunderts. Für den Chemieunterricht ergeben sich daraus zwei Aspekte: Einerseits können Konzepte der informatischen Bildung dabei helfen, chemie- und naturwissenschaftsspezifische Denk- und Arbeitsweisen zu fördern. Andererseits kann der Chemieunterricht einen Beitrag für die informatische Bildung leisten. Dieser Artikel geht auf beide Aspekte ein und versucht die gegenseitigen Vorteile der informatischen Bildung und der naturwissenschaftlichen Bildung im Chemieunterricht darzustellen. T2 - Science education and computer literacy KW - computer literacy KW - scientific literacy KW - informatische Bildung KW - naturwissenschaftliche Bildung Y1 - 2021 U6 - https://doi.org/10.1002/ckon.202100008 SN - 0944-5846 SN - 1521-3730 VL - 28 IS - 6 SP - 263 EP - 265 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Zhou, Shuo A1 - Xu, Xun A1 - Ma, Nan A1 - Jung, Friedrich A1 - Lendlein, Andreas T1 - Influence of sterilization conditions on sulfate-functionalized polyGGE JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Sulfated biomolecules are known to influence numerous biological processes in all living organisms. Particularly, they contribute to prevent and inhibit the hypercoagulation condition. The failure of polymeric implants and blood contacting devices is often related to hypercoagulation and microbial contamination. Here, bioactive sulfated biomacromolecules are mimicked by sulfation of poly(glycerol glycidyl ether) (polyGGE) films. Autoclaving, gamma-ray irradiation and ethylene oxide (EtO) gas sterilization techniques were applied to functionalized materials. The sulfate group density and hydrophilicity of sulfated polymers were decreased while chain mobility and thermal degradation were enhanced post autoclaving when compared to those after EtO sterilization. These results suggest that a quality control after sterilization is mandatory to ensure the amount and functionality of functionalized groups are retained. KW - Sulfated polymer KW - sulfation KW - sterilization KW - ethylene oxide Y1 - 2021 U6 - https://doi.org/10.3233/CH-211241 SN - 1386-0291 SN - 1875-8622 VL - 79 IS - 4 SP - 597 EP - 608 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Harmanli, İpek A1 - Tarakina, Nadezda A1 - Antonietti, Markus A1 - Oschatz, Martin T1 - "Giant" nitrogen uptake in ionic liquids confined in carbon pores JF - Journal of the American Chemical Society N2 - Ionic liquids are well known for their high gas absorption capacity. It is shown that this is not a solvent constant, but can be enhanced by another factor of 10 by pore confinement, here of the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate (EmimOAc) in the pores of carbon materials. A matrix of four different carbon compounds with micro- and mesopores as well as with and without nitrogen doping is utilized to investigate the influence of the carbons structure on the nitrogen uptake in the pore-confined EmimOAc. In general, the absorption is most improved for IL in micropores and in nitrogen-doped carbon. This effect is so large that it is already seen in TGA and DSC experiments. Due to the low vapor pressure of the IL, standard volumetric sorption experiments can be used to quantify details of this effect. It is reasoned that it is the change of the molecular arrangement of the ions in the restricted space of the pores that creates additional free volume to host molecular nitrogen. Y1 - 2021 U6 - https://doi.org/10.1021/jacs.1c00783 SN - 0002-7863 SN - 1520-5126 VL - 143 IS - 25 SP - 9377 EP - 9384 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Figueroa Campos, Gustavo Adolfo A1 - Perez, Jeffrey Paulo H. A1 - Block, Inga A1 - Sagu Tchewonpi, Sorel A1 - Saravia Celis, Pedro A1 - Taubert, Andreas A1 - Rawel, Harshadrai Manilal T1 - Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency JF - Processes : open access journal N2 - The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost adsorbent with prospective to compete with commercial carbons. So far, very few studies have referred to the valorization of coffee parchment into activated carbon. Moreover, low-cost and efficient activation methods need to be more investigated. The aim of this work was to prepare activated carbon from spent coffee grounds and parchment, and to assess their adsorption performance. The co-calcination processing with calcium carbonate was used to prepare the activated carbons, and their adsorption capacity for organic acids, phenolic compounds and proteins was evaluated. Both spent coffee grounds and parchment showed yields after the calcination and washing treatments of around 9.0%. The adsorption of lactic acid was found to be optimal at pH 2. The maximum adsorption capacity of lactic acid with standard commercial granular activated carbon was 73.78 mg/g, while the values of 32.33 and 14.73 mg/g were registered for the parchment and spent coffee grounds activated carbons, respectively. The Langmuir isotherm showed that lactic acid was adsorbed as a monolayer and distributed homogeneously on the surface. Around 50% of total phenols and protein content from coffee wastewater were adsorbed after treatment with the prepared activated carbons, while 44, 43, and up to 84% of hydrophobic compounds were removed using parchment, spent coffee grounds and commercial activated carbon, respectively; the adsorption efficiencies of hydrophilic compounds ranged between 13 and 48%. Finally, these results illustrate the potential valorization of coffee by-products parchment and spent coffee grounds into activated carbon and their use as low-cost adsorbent for the removal of organic compounds from aqueous solutions. KW - coffee by-products KW - spent coffee grounds KW - parchment KW - valorization KW - calcination KW - activated carbon KW - organic compounds adsorption Y1 - 2021 U6 - https://doi.org/10.3390/pr9081396 SN - 2227-9717 VL - 9 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Breternitz, Joachim A1 - Schorr, Susan T1 - Symmetry relations in wurtzite nitrides and oxide nitrides and the curious case of Pmc2(1) JF - Acta crystallographica / International Union of Crystallography. Section A, Foundations and advances N2 - Binary III-V nitrides such as AlN, GaN and InN in the wurtzite-type structure have long been considered as potent semiconducting materials because of their optoelectronic properties, amongst others. With rising concerns over the utilization of scarce elements, a replacement of the trivalent cations by others in ternary and multinary nitrides has led to the development of different variants of nitrides and oxide nitrides crystallizing in lower-symmetry variants of wurtzite. This work presents the symmetry relationships between these structural types specific to nitrides and oxide nitrides and updates some prior work on this matter. The non-existence of compounds crystallizing in Pmc2(1), formally the highest subgroup of the wurtzite type fulfilling Pauling's rules for 1:1:2 stoichiometries, has been puzzling scientists for a while; a rationalization is given, from a crystallographic basis, of why this space group is unlikely to be adopted. KW - group-subgroup relationships KW - nitride materials KW - wurtzite type Y1 - 2021 U6 - https://doi.org/10.1107/S2053273320015971 SN - 2053-2733 VL - 77 IS - 3 SP - 208 EP - 216 PB - Blackwell CY - Oxford [u.a.] ER - TY - JOUR A1 - Rothe, Martin A1 - Zhao, Yuhang A1 - Müller, Johannes A1 - Kewes, Günter A1 - Koch, Christoph T. A1 - Lu, Yan A1 - Benson, Oliver T1 - Self-assembly of plasmonic nanoantenna-waveguide structures for subdiffractional chiral sensing JF - ACS nano N2 - Spin-momentum locking is a peculiar effect in the near-field of guided optical or plasmonic modes. It can be utilized to map the spinning or handedness of electromagnetic fields onto the propagation direction. This motivates a method to probe the circular dichroism of an illuminated chiral object. In this work, we demonstrate local, subdiffraction limited chiral coupling of light and propagating surface plasmon polaritons in a self-assembled system of a gold nanoantenna and a silver nanowire. A thin silica shell around the nanowire provides precise distance control and also serves as a host for fluorescent molecules, which indicate the direction of plasmon propagation. We characterize our nanoantenna-nanowire systems comprehensively through correlated electron microscopy, energy-dispersive X-ray spectroscopy, dark-field, and fluorescence imaging. Three-dimensional numerical simulations support the experimental findings. Besides our measurement of far-field polarization, we estimate sensing capabilities and derive not only a sensitivity of 1 mdeg for the ellipticity of the light field, but also find 10(3) deg cm(2)/dmol for the circular dichroism of an analyte locally introduced in the hot spot of the antenna-wire system. Thorough modeling of a prototypical design predicts on-chip sensing of chiral analytes. This introduces our system as an ultracompact sensor for chiral response far below the diffraction limit. KW - plasmonics KW - nanoparticle assemblies KW - core-shell KW - spin-orbit coupling KW - chirality KW - circular dichroism KW - nano-optics Y1 - 2021 U6 - https://doi.org/10.1021/acsnano.0c05240 SN - 1936-0851 SN - 1936-086X VL - 15 IS - 1 SP - 351 EP - 361 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Lau, Skadi A1 - Liu, Yue A1 - Maier, Anna A1 - Braune, Steffen A1 - Gossen, Manfred A1 - Neffe, Axel T. A1 - Lendlein, Andreas T1 - Establishment of an in vitro thrombogenicity test system with cyclic olefin copolymer substrate for endothelial layer formation JF - MRS communications / a publication of the Materials Research Society N2 - In vitro thrombogenicity test systems require co-cultivation of endothelial cells and platelets under blood flow-like conditions. Here, a commercially available perfusion system is explored using plasma-treated cyclic olefin copolymer (COC) as a substrate for the endothelial cell layer. COC was characterized prior to endothelialization and co-cultivation with platelets under static or flow conditions. COC exhibits a low roughness and a moderate hydrophilicity. Flow promoted endothelial cell growth and prevented platelet adherence. These findings show the suitability of COC as substrate and the importance of blood flow-like conditions for the assessment of the thrombogenic risk of drugs or cardiovascular implant materials. Y1 - 2021 U6 - https://doi.org/10.1557/s43579-021-00072-6 SN - 2159-6867 VL - 11 IS - 5 SP - 559 EP - 567 PB - Springer CY - Berlin ER - TY - JOUR A1 - Zhao, Yuhang A1 - Opitz, Andreas A1 - Eljarrat, Alberto A1 - Kochovski, Zdravko A1 - Koch, Christoph A1 - Koch, Norbert A1 - Lu, Yan T1 - Kinetic study on the adsorption of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane on Ag nanoparticles in chloroform BT - implications for the charge transfer complex of Ag-F(4)TCNQ JF - ACS applied nano materials N2 - In this study, the kinetics of the adsorption of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ) on the surface of Ag nanoparticles (Ag NPs) in chloroform has been intensively investigated, as molecular doping is known to play a crucial role in organic electronic devices. Based on the results obtained from UV-visible (vis)-near-infrared (NIR) absorption spectroscopy, cryogenic transmission electron microscopy, scanning nanobeam electron diffraction, and electron energy loss spectroscopy, a two-step interaction kinetics has been proposed for the Ag NPs and F(4)TCNQ molecules, which includes the first step of electron transfer from Ag NPs to F(4)TCNQ indicated by the ionization of F(4)TCNQ and the second step of the formation of a Ag-F(4)TCNQ complex. The whole process has been followed via UV-vis-NIR absorption spectroscopy, which reveals distinct kinetics at two stages: the instantaneous ionization and the long-term complex formation. The kinetics and the influence of the molar ratio of Ag NPs/F(4)TCNQ molecules on the interaction between Ag NPs and F(4)TCNQ molecules in an organic solution are reported herein for the first time. Furthermore, the control experiment with silica-coated Ag NPs manifests that the charge transfer at the surface between Ag NPs and F(4)TCNQ molecules is prohibited by a silica layer of 18 nm. KW - Ag nanoparticles KW - F(4)TCNQ KW - phase transfer KW - kinetics KW - electron transfer KW - surface interaction Y1 - 2021 U6 - https://doi.org/10.1021/acsanm.1c02153 SN - 2574-0970 VL - 4 IS - 11 SP - 11625 EP - 11635 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Saeedi Garakani, Sadaf A1 - Xie, Dongjiu A1 - Khorsand Kheirabad, Atefeh A1 - Lu, Yan A1 - Yuan, Jiayin T1 - Template-synthesis of a poly(ionic liquid)-derived Fe1-xS/nitrogen-doped porous carbon membrane and its electrode application in lithium-sulfur batteries JF - Materials advances N2 - This study deals with the facile synthesis of Fe1-xS nanoparticle-containing nitrogen-doped porous carbon membranes (denoted as Fe1-xS/N-PCMs) via vacuum carbonization of hybrid porous poly(ionic liquid) (PIL) membranes, and their successful use as a sulfur host material to mitigate the shuttle effect in lithium-sulfur (Li-S) batteries. The hybrid porous PIL membranes as the sacrificial template were prepared via ionic crosslinking of a cationic PIL with base-neutralized 1,1 '-ferrocenedicarboxylic acid, so that the iron source was molecularly incorporated into the template. The carbonization process was investigated in detail at different temperatures, and the chemical and porous structures of the carbon products were comprehensively analyzed. The Fe1-xS/N-PCMs prepared at 900 degrees C have a multimodal pore size distribution with a satisfactorily high surface area and well-dispersed iron sulfide nanoparticles to physically and chemically confine the LiPSs. The sulfur/Fe1-xS/N-PCM composites were then tested as electrodes in Li-S batteries, showing much improved capacity, rate performance and cycle stability, in comparison to iron sulfide-free, nitrogen-doped porous carbon membranes. Y1 - 2021 U6 - https://doi.org/10.1039/d1ma00441g SN - 2633-5409 VL - 2 IS - 15 SP - 5203 EP - 5212 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Melani, Giacomo A1 - Nagata, Yuki A1 - Saalfrank, Peter T1 - Vibrational energy relaxation of interfacial OH on a water-covered alpha-Al2O3(0001) surface BT - a non-equilibrium ab initio molecular dynamics study JF - Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies N2 - Vibrational relaxation of adsorbates is a sensitive tool to probe energy transfer at gas/solid and liquid/solid interfaces. The most direct way to study relaxation dynamics uses time-resolved spectroscopy. Here we report on a non-equilibrium ab initio molecular dynamics (NE-AIMD) methodology to model vibrational relaxation of OH vibrations on a hydroxylated, water-covered alpha-Al2O3(0001) surface. In our NE-AIMD approach, after exciting selected O-H bonds their coupling to surface phonons and to the water adlayer is analyzed in detail, by following both the energy flow in time, as well as the time-evolution of Vibrational Density of States (VDOS) curves. The latter are obtained from Time-dependent Correlation Functions (TCFs) and serve as prototypical, generic representatives of time-resolved vibrational spectra. As most important results, (i) we find a few-picosecond lifetime of the excited modes and (ii) identify both hydrogen-bonded aluminols and water molecules in the adsorbed water layer as main dissipative channels, while the direct coupling to Al2O3 surface phonons is of minor importance on the timescales of interest. Our NE-AIMD/TCF methodology is powerful for complex adsorbate systems, in principle even reacting ones, and opens a way towards time-resolved vibrational spectroscopy. Y1 - 2021 U6 - https://doi.org/10.1039/d0cp03777j SN - 1463-9076 SN - 1463-9084 VL - 23 IS - 13 SP - 7714 EP - 7723 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Wang, Zhenyu A1 - Fritsch, Daniel A1 - Berendts, Stefan A1 - Lerch, Martin A1 - Breternitz, Joachim A1 - Schorr, Susan T1 - Elucidation of the reaction mechanism for the synthesis of ZnGeN2 through Zn2GeO4 ammonolysis JF - Chemical science / RSC, Royal Society of Chemistry N2 - Ternary II-IV-N-2 materials have been considered as a promising class of materials that combine photovoltaic performance with earth-abundance and low toxicity. When switching from binary III-V materials to ternary II-IV-N-2 materials, further structural complexity is added to the system that may influence its optoelectronic properties. Herein, we present a systematic study of the reaction of Zn2GeO4 with NH3 that produces zinc germanium oxide nitrides, and ultimately approach stoichiometric ZnGeN2, using a combination of chemical analyses, X-ray powder diffraction and DFT calculations. Elucidating the reaction mechanism as being dominated by Zn and O extrusion at the later reaction stages, we give an insight into studying structure-property relationships in this emerging class of materials. Y1 - 2021 U6 - https://doi.org/10.1039/d1sc00328c SN - 2041-6539 VL - 12 IS - 24 SP - 8493 EP - 8500 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Nicolai, Merle Marie A1 - Weishaupt, Ann-Kathrin A1 - Baesler, Jessica A1 - Brinkmann, Vanessa A1 - Wellenberg, Anna A1 - Winkelbeiner, Nicola Lisa A1 - Gremme, Anna A1 - Aschner, Michael A1 - Fritz, Gerhard A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Effects of manganese on genomic integrity in the multicellular model organism Caenorhabditis elegans JF - International Journal of Molecular Sciences N2 - Although manganese (Mn) is an essential trace element, overexposure is associated with Mn-induced toxicity and neurological dysfunction. Even though Mn-induced oxidative stress is discussed extensively, neither the underlying mechanisms of the potential consequences of Mn-induced oxidative stress on DNA damage and DNA repair, nor the possibly resulting toxicity are characterized yet. In this study, we use the model organism Caenorhabditis elegans to investigate the mode of action of Mn toxicity, focusing on genomic integrity by means of DNA damage and DNA damage response. Experiments were conducted to analyze Mn bioavailability, lethality, and induction of DNA damage. Different deletion mutant strains were then used to investigate the role of base excision repair (BER) and dePARylation (DNA damage response) proteins in Mn-induced toxicity. The results indicate a dose- and time-dependent uptake of Mn, resulting in increased lethality. Excessive exposure to Mn decreases genomic integrity and activates BER. Altogether, this study characterizes the consequences of Mn exposure on genomic integrity and therefore broadens the molecular understanding of pathways underlying Mn-induced toxicity. Additionally, studying the basal poly(ADP-ribosylation) (PARylation) of worms lacking poly(ADP-ribose) glycohydrolase (PARG) parg-1 or parg-2 (two orthologue of PARG), indicates that parg-1 accounts for most of the glycohydrolase activity in worms. KW - manganese KW - oxidative stress KW - DNA repair KW - DNA damage response KW - Caenorhabditis elegans Y1 - 2021 U6 - https://doi.org/10.3390/ijms222010905 SN - 1422-0067 VL - 22 IS - 20 PB - MDPI CY - Basel ER - TY - JOUR A1 - Geiger, Christina A1 - Reitenbach, Julija A1 - Henschel, Cristiane A1 - Kreuzer, Lucas A1 - Widmann, Tobias A1 - Wang, Peixi A1 - Mangiapia, Gaetano A1 - Moulin, Jean-François A1 - Papadakis, Christine M. A1 - Laschewsky, André A1 - Müller-Buschbaum, Peter T1 - Ternary nanoswitches realized with multiresponsive PMMA-b-PNIPMAM films in mixed water/acetone vapor atmospheres JF - Advanced engineering materials N2 - To systematically add functionality to nanoscale polymer switches, an understanding of their responsive behavior is crucial. Herein, solvent vapor stimuli are applied to thin films of a diblock copolymer consisting of a short poly(methyl methacrylate) (PMMA) block and a long poly(N-isopropylmethacrylamide) (PNIPMAM) block for realizing ternary nanoswitches. Three significantly distinct film states are successfully implemented by the combination of amphiphilicity and co-nonsolvency effect. The exposure of the thin films to nitrogen, pure water vapor, and mixed water/acetone (90 vol%/10 vol%) vapor switches the films from a dried to a hydrated (solvated and swollen) and a water/acetone-exchanged (solvated and contracted) equilibrium state. These three states have distinctly different film thicknesses and solvent contents, which act as switch positions "off," "on," and "standby." For understanding the switching process, time-of-flight neutron reflectometry (ToF-NR) and spectral reflectance (SR) studies of the swelling and dehydration process are complemented by information on the local solvation of functional groups probed with Fourier-transform infrared (FTIR) spectroscopy. An accelerated responsive behavior beyond a minimum hydration/solvation level is attributed to the fast build-up and depletion of the hydration shell of PNIPMAM, caused by its hydrophobic moieties promoting a cooperative hydration character. KW - co-nonsolvency KW - diblock copolymers KW - nanoswitches KW - neutron reflectometry KW - thin films Y1 - 2021 U6 - https://doi.org/10.1002/adem.202100191 SN - 1438-1656 SN - 1527-2648 VL - 23 IS - 11 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Quan, Ting A1 - Haerk, Eneli A1 - Xu, Yaolin A1 - Ahmet, Ibbi A1 - Höhn, Christian A1 - Mei, Shilin A1 - Lu, Yan T1 - Unveiling the formation of solid electrolyte interphase and its temperature dependence in "Water-in-Salt" supercapacitors JF - ACS applied materials & interfaces N2 - "Water-in-salt" (WIS) electrolytes have emerged as an excellent superconcentrated ionic medium for high-power energy storage systems such as supercapacitors due to their extended working potential compared to the conventional dilute aqueous electrolyte. In this work, we have investigated the performance of WIS supercapacitors using hollow carbon nanoplates as electrodes and compared it to that based on the conventional "salt-in-water" electrolytes. Moreover, the potentiostatic electrochemical impedance spectroscopy has been employed to provide an insightful look into the charge transport properties, which also, for the first time, reveals the formation of a solid-electrolyte interphase (SEI and their temperature-dependent impedance for charge transfer and adsorption. Furthermore, the effect of temperature on the electrochemical performance of the WIS supercapacitors in the temperature range from 15 to 60 degrees C has been studied, which presents a gravimetric capacitance of 128 F g(-1) and a volumetric capacitance of 197.12 F cm(-3) at 55 degrees C compared to 87.5 F g(-1) and 134.75 F cm(-3) at 15 degrees C. The in-depth understanding about the formation of SEI layer and the electrochemical performance at different temperatures for WIS supercapacitors will assist the efforts toward designing better aqueous electrolytes for supercapacitors. KW - "water-in-salt" KW - supercapacitor KW - solid electrolyte interphase KW - electrochemical impedance spectroscopy KW - temperature effect Y1 - 2021 U6 - https://doi.org/10.1021/acsami.0c19506 SN - 1944-8244 SN - 1944-8252 VL - 13 IS - 3 SP - 3979 EP - 3990 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schlappa, Stephanie A1 - Brenker, Lee Josephine A1 - Bressel, Lena A1 - Hass, Roland A1 - Münzberg, Marvin T1 - Process characterization of polyvinyl acetate emulsions applying inline photon density wave spectroscopy at high solid contents JF - Polymers / Molecular Diversity Preservation International N2 - The high solids semicontinuous emulsion polymerization of polyvinyl acetate using poly (vinyl alcohol-co-vinyl acetate) as protective colloid is investigated by optical spectroscopy. The suitability of Photon Density Wave (PDW) spectroscopy as inline Process Analytical Technology (PAT) for emulsion polymerization processes at high solid contents (>40% (w/w)) is studied and evaluated. Inline data on absorption and scattering in the dispersion is obtained in real-time. The radical polymerization of vinyl acetate to polyvinyl acetate using ascorbic acid and sodium persulfate as redox initiator system and poly (vinyl alcohol-co-vinyl acetate) as protective colloid is investigated. Starved-feed radical emulsion polymerization yielded particle sizes in the nanometer size regime. PDW spectroscopy is used to monitor the progress of polymerization by studying the absorption and scattering properties during the synthesis of dispersions with increasing monomer amount and correspondingly decreasing feed rate of protective colloid. Results are compared to particle sizes determined with offline dynamic light scattering (DLS) and static light scattering (SLS) during the synthesis. KW - photon density wave spectroscopy KW - multiple light scattering KW - emulsion KW - polymerization KW - process analytical technology KW - polyvinyl acetate Y1 - 2021 U6 - https://doi.org/10.3390/polym13040669 SN - 2073-4360 VL - 13 IS - 4 PB - MDPI CY - Basel ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Koch, Andreas T1 - Intramolecular carbene stabilization via 3c,2e bonding on basis of the magnetic criterion JF - Tetrahedron : the international journal for the rapid publication of full original research papers and critical reviews in organic chemistry N2 - The spatial magnetic properties, through-space NMR shieldings (TSNMRS), of bent cyclobutylcarbene 8, 1,2-diboretane-3-ylidene 9, and some carbene analogues of boron 14-18 as most intriguing examples of carbenes, which can be stabilized as homoaromatic systems with 3c,2e bonding, have been calculated using the GIAO perturbation method employing the nucleus independent chemical shift (NICS) concept and the results visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. The TSNMRS values (actually, ring current effect/anisotropy effects as measurable in H-1 NMR spectroscopy) are employed to qualify and quantify the degree of present 3c,2e-homoaromaticity. Results are confirmed by geometry (bond angles and bond lengths) and spectroscopic data, the delta(B-11)/ppm data and the C-13 chemical shifts of the carbene electron-deficient centre. KW - Cyclobutylcarbene KW - 1,2-diboretane-3-ylidene KW - 3c,2e-bonding KW - Through-space NMR shieldings (TSNMRS) KW - NICS Y1 - 2021 U6 - https://doi.org/10.1016/j.tet.2021.132357 SN - 0040-4020 SN - 1464-5416 VL - 95 PB - Elsevier Science CY - Amsterdam ER - TY - JOUR A1 - Buyinza, Daniel A1 - Derese, Solomon A1 - Ndakala, Albert A1 - Heydenreich, Matthias A1 - Yenesew, Abiy A1 - Koch, Andreas A1 - Oriko, Richard T1 - A coumestan and a coumaronochromone from Millettia lasiantha JF - Biochemical systematics and ecology N2 - The manuscript describes the phytochemical investigation of the roots, leaves and stem bark of Millettia lasiantha resulting in the isolation of twelve compounds including two new isomeric isoflavones lascoumestan and las-coumaronochromone. The structures of the new compounds were determined using different spectroscopic techniques. KW - Millettia lasiantha KW - Leguminosae KW - Coumestan KW - Coumaronochromone Y1 - 2021 U6 - https://doi.org/10.1016/j.bse.2021.104277 SN - 0305-1978 SN - 1873-2925 VL - 97 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Xu, Xun A1 - Nie, Yan A1 - Wang, Weiwei A1 - Ma, Nan A1 - Lendlein, Andreas T1 - Periodic thermomechanical modulation of toll-like receptor expression and distribution in mesenchymal stromal cells JF - MRS communications / a publication of the Materials Research Society N2 - Toll-like receptor (TLR) can trigger an immune response against virus including SARS-CoV-2. TLR expression/distribution is varying in mesenchymal stromal cells (MSCs) depending on their culture environments. Here, to explore the effect of periodic thermomechanical cues on TLRs, thermally controlled shape-memory polymer sheets with programmable actuation capacity were created. The proportion of MSCs expressing SARS-CoV-2-associated TLRs was increased upon stimulation. The TLR4/7 colocalization was promoted and retained in the endoplasmic reticula. The TLR redistribution was driven by myosin-mediated F-actin assembly. These results highlight the potential of boosting the immunity for combating COVID-19 via thermomechanical preconditioning of MSCs. KW - Actuation KW - Antiviral KW - Biomaterial KW - COVID-19 KW - Shape memory Y1 - 2021 U6 - https://doi.org/10.1557/s43579-021-00049-5 SN - 2159-6867 VL - 11 IS - 4 SP - 425 EP - 431 PB - Springer CY - Berlin ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Koch, Andreas T1 - Dative or coordinative carbon-boron bond in boron trapped N-heterocyclic carbenes (NHCs)? BT - an answer given on the magnetic criterion JF - Tetrahedron : the international journal for the rapid publication of full original research papers and critical reviews in organic chemistry N2 - The spatial magnetic properties, through-space NMR shieldings (TSNMRS), of isolated as well as B-C bond length varied model compounds (BR3 trapped NHCs) have been calculated using the GIAO perturbation method employing the nucleus independent chemical shift (NICS) concept and the results visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. The TSNMRS values (actually the anisotropy effects measurable in H-1 NMR spectroscopy) are employed to qualify and quantify the present dative vs. coordinative bond character of the boron-carbon bond in the trapped NHCs. Results are confirmed by bond lengths and B-11/C-13 chemical shift variations in the BR3 trapped NHCs. KW - NHCs KW - Dative vs. coordinative NHC -> BR3 bond KW - Through-space NMR KW - shieldings (TSNMRS) KW - NICS KW - Anisotropy effect Y1 - 2021 U6 - https://doi.org/10.1016/j.tet.2020.131787 SN - 0040-4020 SN - 1464-5416 VL - 80 PB - Elsevier CY - Amsterdam ER -