IR Spectroscopy as a Method for Online Electrolyte State Assessment in RFBs

Abstract The transition from fossil to renewable energy sources requires adequate storage technologies due to the intermittency of the supplied energy. With respect to this, organic redox‐flow batteries (ORFBs) represent a promising concept for the storage of electricity on a large scale at economically justifiable costs. However, these storage technologies can only be operated reliably if parameters representing the actual condition of the storage medium (i.e., the electrolyte) can be accurately assessed. These so‐called electrolyte state variables are represented by two key figures of merit: state of charge (SOC), a measure of the amount of charge that the electrolyte currently holds; and state of health (SOH), representing the amount of charge that the electrolyte is able to store given its current condition. The herein presented IR‐based approach is able to simultaneously provide reliable, fast, accurate, and precise estimates for both SOC and SOH parameters at any point in time and independent of the current battery status. The method is able to provide a time resolution in the range of minutes, is independent of the electrolyte temperature and can be applied to nearly all organic‐based redox‐active materials and solvents, while potentially being applicable to inorganic RFBs, such as vanadium‐based systems, as well.Redox‐flow batteries (RFBs) provide a unique and scalable storage solution for green energy. However, they can only be operated safely when parameters representing the battery state are precisely known at any point in time. The presented IR‐spectroscopic method is able to generate accurate and precise estimates for the crucial State‐of‐Charge and State‐of‐Health variables of RFB electrolytes. imag

Selective metal‐complexation on polymeric templates and their investigation via isothermal titration calorimetry

Selective complexation of metal ions represents a powerful tool for the development of versatile supramolecular architectures. While research in the field of molecular devices and machinery is sophisticated, the selective formation of metal complexes is not prevalent in polymer chemistry. Thus, the implementation of orthogonal binding concepts into a polymeric matrix is presented. In this context, an end‐functionalized poly( N ‐isopropylacrylamide) (PNIPAm) carrying zinc‐porphyrin (ZnTPP) as well as a terpyridine (tpy) ligand side by side is utilized. With these binding sites, the polymer can simultaneously interact with a pyridine moiety via a ZnTPP interaction and a terpyridine unit by the formation of a bis‐terpyridine complex. The complexation behavior of this polymer and different model compounds is intensively investigated by isothermal titration calorimetry. The obtained results indicate that the reported orthogonality of these two systems is successfully transferred into a functional polymeric architecture

Comparing Microwave and Classical Synthesis of Oxymethylene Dimethyl Ethers

Polyoxymethylene dimethyl ethers (OME n ) are considered as substituents or additives for fossil diesel fuel. Efficiency of the synthesis is crucial for the development of industrial scale production plants. Therefore, the design of suitable catalysts and the efficient heating play important roles in OME fuel synthesis. In this work, microwave‐assisted synthesis (MAS) is carried out and compared to a classical approach using standard thermal heating. Different polymeric materials, e.g., Amerlyst15, are utilized as catalysts, and screened for the catalytic synthesis of OME. Within this approach, the kinetics of the reaction are analyzed in detail

Hydrophilic Crosslinked TEMPO‐Methacrylate Copolymers – a Straight Forward Approach towards Aqueous Semi‐Organic Batteries

Abstract Crosslinked hydrophilic poly(2,2,6,6‐tetramethylpiperidinyl‐ N ‐oxyl‐co‐[2‐(methacryloyloxy)‐ethyl]trimethyl ammonium chloride) [poly(TEMPO‐ co ‐METAC)] polymers with different monomer ratios are synthesized and characterized regarding a utilization as electrode material in organic batteries. These polymers can be synthesized rapidly utilizing commercial starting materials and reveal an increased hydrophilicity compared to the state‐of‐the‐art poly(2,2,6,6‐tetramethylpiperidinyl‐ N ‐oxyl‐4‐methacrylate) (PTMA). By increasing the hydrophilicity of the polymer, a preparation of cathode composites is enabled, which can be used for aqueous semi‐organic batteries. Detailed battery testing confirms that the additional METAC groups do not impair the battery behavior while enabling straight‐forward zinc‐TEMPO batteries.Organic cathode in aqueous electrolyte : A crosslinked hydrophilic 2,2,6,6‐tetramethylpiperidine‐ N ‐oxyl radical (TEMPO) bearing polymer was synthesized, which enables aqueous battery chemistries that have not been compatible with poly(TEMPO‐methacrylate) derived structures before. Extensive battery testing was performed, to reveal the battery chemistry of the polymer containing composite electrodes in an aqueous semi‐organic zinc coin‐cell setup. imag

Quantification of triple‐shape memory behavior of polymers utilizing tension and torsion

Abstract Shape‐memory polymers (SMPs) are well investigated smart materials. With their ability to memorize their original shape they are interesting candidates for a large range of applications. Certain SMPs feature triple shape‐memory behavior. In these cases, it is possible to fix two different temporary shapes. However, the exact quantification of the individual steps regarding their programming and recovery rate is difficult and has not been possible so far. In this work, a novel approach for the analysis and exact quantification of triple SMPs is presented. By applying a customized rheology protocol, it is possible to perform and to analyze torsional and tensional experiments simultaneously. Consequently, different shapes in different directions (vertical and horizontal) can be fixed and the individual steps can be investigated independently at different switching temperatures

State of charge and state of health assessment of viologens in aqueous-organic redox-flow electrolytes using in situ IR spectroscopy and multivariate curve resolution

Aqueous-organic redox flow batteries (RFBs) have gained considerable interest in recent years, given their potential for an economically viable energy storage at large scale. This, however, strongly depends on both the robustness of the underlying electrolyte chemistry against molecular decomposition reactions as well as the device's operation. With regard to this, the presented study focuses on the use of in situ IR spectroscopy in combination with a multivariate curve resolution approach to gain insight into both the molecular structures of the active materials present within the electrolyte as well as crucial electrolyte state parameters, represented by the electrolyte's state of charge (SOC) and state of health (SOH). To demonstrate the general applicability of the approach, methyl viologen (MV) and bis(3-trimethylammonium)propyl viologen (BTMAPV) are chosen, as viologens are frequently used as negolytes in aqueous-organic RFBs. The study's findings highlight the impact of in situ spectroscopy and spectral deconvolution tools on the precision of the obtainable SOC and SOH values. Furthermore, the study indicates the occurrence of multiple viologen dimers, which possibly influence the electrolyte lifetime and charging characteristics

Novel Biobased Self-Healing Ionomers Derived from Itaconic Acid Derivates

This article presents novel biobased ionomers featuring self-healing abilities. These smart materials are synthesized from itaconic acid derivates. Large quantities of itaconic acid can be produced from diverse biomass like corn, rice, and others. This study presents a comprehensive investigation of their thermal and mechanical properties via differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), and FT-Raman and FT-IR measurements as well as dynamic mechanic analysis. Within all these measurements, different kinds of structure-property relationships could be derived from these measurements. For example, the proportion of ionic groups enormously influences the self-healing efficiency. The investigation of the self-healing abilities reveals healing efficiencies up to 99% in 2 h at 90 °C for the itaconic acid based ionomer with the lowest ionic content. © 2020 The Authors. Macromolecular Rapid Communications published by Wiley-VCH Gmb

A viologen polymer and a compact ferrocene: Comparison of solution viscosities and their performance in a redox flow battery with a size exclusion membrane

In this work, the synthesis and characterization of a compact, ferrocene tetramer and a linear viologen polymer is reported. The latter material is a new, 4,4′‐bipyridine containing, organo‐soluble polymer. As aimed for solubility in nonpolar solvents, a 2‐ethylhexyl‐moiety to promote organosolubility and 4‐vinylbenzyl serving as a polymerizable group are introduced to a 4,4′‐bipyridine. The halide anions of the monomer cation are exchanged to bis(trifluoromethansulfon)imide, which further enhances organosolubility. The monomer is subsequently copolymerized with styrene by free radical polymerization. In addition, a four‐ferrocene‐containing compact structure, based on pentaerythritol, is synthesized via the straightforward radical thiol‐ene reaction. The polymer solutions are thoroughly characterized hydrodynamically. Subsequently, propylene carbonate‐based solutions of both materials are prepared to allow an assessment for future energy storage applications. This is done by testing battery characteristics in a custom‐made flow‐cell with a simple dialysis membrane for physical separation of the active materials. The capability of energy storage is verified by leaving the charged materials in solution in an open circuit for 24 h. Here, more than 99% of the stored charges can be recovered. Cycling the battery for 100 times reveals the remarkable stability of the materials of only 0.2% capacity loss per day in the battery setup

Aqueous Redox Flow Battery Suitable for High Temperature Applications Based on a Tailor‐Made Ferrocene Copolymer

Abstract Water‐soluble, and ferrocene‐containing methacrylamide copolymers with different comonomer ratios of the solubility‐promoting comonomer [2‐(methacryloyloxy)‐ethyl]‐trimethylammonium chloride (METAC) are synthesized in order to obtain a novel, temperature‐stable electrolyte for aqueous redox flow batteries. The electrochemical properties of one chosen polymer are studied in detail by cyclic voltammetry and rotating disc electrode (RDE) investigations. Additionally, the diffusion coefficient and the charge transfer rate are obtained from these measurements. The diffusion coefficient from RDE is compared to the value from synthetic boundary experiments at battery concentrations, using an analytical ultracentrifuge, yielding diffusion coefficients of a similar order of magnitude. The polymer is further tested in a redox flow battery setup. While performing charge and discharge experiments against the well‐established bis ‐(trimethylammoniumpropyl)‐viologen, the polymer reveals high columbic efficiencies of >99.8% and desirable apparent capacity retention, both at room temperature as well as at 60 °C. Further experiments are conducted to verify the stability of the active compounds under these conditions in both charge states. Lastly, the electrochemical behavior is linked to the characteristics of the polymers concerning absolute values of the molar mass and diffusion coefficients.A new ferrocene containing monomer is synthesized and its copolymerization with a water‐solubility promoting comonomer is investigated. The electrochemical and solution characteristics of a corresponding polymer are studied in detail. With a coulombic efficiency of >99.8% in an aqueous redox flow battery setup at 60 °C, a cheap, robust system for use at elevated temperatures is presented. imag

Live Cell Imaging Unveils Multiple Domain Requirements for In Vivo Dimerization of the Glucocorticoid Receptor

Glucocorticoids are essential for life, but are also implicated in disease pathogenesis and may produce unwanted effects when given in high doses. Glucocorticoid receptor (GR) transcriptional activity and clinical outcome have been linked to its oligomerization state. Although a point mutation within the GR DNA-binding domain (GRdim mutant) has been reported as crucial for receptor dimerization and DNA binding, this assumption has recently been challenged. Here we have analyzed the GR oligomerization state in vivo using the number and brightness assay. Our results suggest a complete, reversible, and DNA-independent ligand-induced model for GR dimerization. We demonstrate that the GRdim forms dimers in vivo whereas adding another mutation in the ligand-binding domain (I634A) severely compromises homodimer formation. Contrary to dogma, no correlation between the GR monomeric/dimeric state and transcriptional activity was observed. Finally, the state of dimerization affected DNA binding only to a subset of GR binding sites. These results have major implications on future searches for therapeutic glucocorticoids with reduced side effects.Fil: Presman, Diego Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Ogara, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Stortz, Martin Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Alvarez, Lautaro Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; ArgentinaFil: Pooley, John R.. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados Unidos. University of Bristol; Reino UnidoFil: Schiltz, R. Louis. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: Grøntved, Lars. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: Johnson, Thomas A.. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: Mittelstadt, Paul R.. National Cancer Institute. Laboratory of Immune Cell Biology; Estados UnidosFil: Ashwell, Jonathan D.. National Cancer Institute. Laboratory of Immune Cell Biology; Estados UnidosFil: Ganesan, Sundar. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados Unidos. National Institute of Allergy and Infectious Diseases; Estados UnidosFil: Burton, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; ArgentinaFil: Levi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Hager, Gordon L.. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: Pecci, Adali. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin