Fraunhofer Institute for Chemical Technology

The development of various redox-flow batteries for the storage of fluctuating renewable energy has intensified in recent years because of their peculiar ability to be scaled separately in terms of energy and power, and therefore potentially to reduce the costs of energy storage. This has resulted in a considerable increase in the number of publications on redox-flow batteries. This was a motivation to present a comprehensive and critical overview of the features of this type of batteries, focusing mainly on the chemistry of electrolytes and introducing a thorough systematic classification to reveal their potential for future development.

Li–S cells are considered a highly attractive electrochemical storage system, especially due to their high potential gravimetric energy density. The long‐term target of all Li–S research activities must be to outperform state‐of‐the‐art Li‐ion cells. A current benchmark is the Panasonic NCR18650B, which has a gravimetric energy density of ≈240 Wh kg −1 and several hundred relatively stable cycles. The possible 18650 Li–S cell energies and cell costs are calculated for various sulfur loads, sulfur utilizations, and electrolyte/sulfur ratios with the aim of determining the cell and electrode property values required to outperform the NCR18650B. These values are compared with statistical information obtained from an extensive literature review of 274 Li–S publications over the last 12 years to show the gap between state‐of‐the‐art Li–S research and requirements for high energy density cells. Finally, a carbon nanotubes‐based electrode is introduced, which meets important criteria for obtaining high gravimetric cell energy densities.

Recent studies have firmly established that cellular uptake of nanoparticles is strongly affected by the presence and the physicochemical properties of a protein adsorption layer around these nanoparticles. Here, we have modified human serum albumin (HSA), a serum protein often used in model studies of protein adsorption onto nanoparticles, to alter its surface charge distribution and investigated the consequences for protein corona formation around small (radius ∼5 nm), dihydrolipoic acid-coated quantum dots (DHLA-QDs) by using fluorescence correlation spectroscopy. HSA modified by succinic anhydride (HSAsuc) to generate additional carboxyl groups on the protein surface showed a 3-fold decreased binding affinity toward the nanoparticles. A 1000-fold enhanced affinity was observed for HSA modified by ethylenediamine (HSAam) to increase the number of amino functions on the protein surface. Remarkably, HSAsuc formed a much thicker protein adsorption layer (8.1 nm) than native HSA (3.3 nm), indicating that it binds in a distinctly different orientation on the nanoparticle, whereas the HSAam corona (4.6 nm) is only slightly thicker. Notably, protein binding to DHLA-QDs was found to be entirely reversible, independent of the modification. We have also measured the extent and kinetics of internalization of these nanoparticles without and with adsorbed native and modified HSA by HeLa cells. Pronounced variations were observed, indicating that even small physicochemical changes of the protein corona may affect biological responses.

A simulation model of biomass gasification for syngas production with steam as gasifying agent and subsequent syngas adjustment has been developed using Aspen Plus. The developed model is based on Gibbs free energy minimization applying the restricted equilibrium method. The objective is to study the effect of important parameters such as gasification temperature, steam to biomass ratio and shift reaction temperature on hydrogen concentration, CO concentration, CO conversion, CO2 conversion and H2/CO ratio in the syngas. Simulations were performed for different biomass feedstocks to predict their syngas composition. The hydrogen and CO concentrations were altered such that the H2/CO molar ratio in the syngas composition gets adjusted close to a value of 2.15 as required for FT synthesis by the shift reaction. The present model has been validated with experimental data from literature on steam biomass gasification conducted in a research scale fluidized bed gasifier. The product gas obtained from steam gasification of food wastes resulted in a composition with a H2/CO molar ratio close to 2.15 which can be directly fed to a Fischer-Tropsch synthesis plant whereas remaining feedstocks requires a syngas adjustment either by WGS or RWGS reactions to achieve H2/CO molar ratio close to 2.15.

S.A1205-A1214

The balance between the market demand and the natural abundance of the rare-earth elements (REEs) in ores, often referred to as the Balance Problem (or the Balancing Problem), is a major issue for REE suppliers. The ideal situation is a perfect match between the market demand for and the production of REEs, so that there are no surpluses of any of the REEs. This means that the rare-earth industry must find new uses for REEs that are available in excess and search for substitutes for REEs that have either limited availability or are high in demand. We present an overview of the trends in the applications for the different REEs and show that the demand for REEs for use in magnets, catalysts, and alloys is still increasing, while the application of REEs in polishing agents, glass, and ceramics are stable. On the other hand, the use of REEs in nickel–metal-hydride (NiMH) batteries and lamp phosphors is decreasing. These changes in the REE market have an influence on the Balance Problem, because the REEs that can be recycled from fluorescent lamps, cathode-ray tubes (CRTs), and NiMH batteries have to be at least partly reused in other applications. Magnesium and aluminum alloys offer an opportunity to mitigate the Balance Problem caused by these changes in the REE market. This is illustrated for REEs that can be recycled from fluorescent-lamp phosphor waste, CRT phosphors, and NiMH batteries. At present, five REEs (Nd, Eu, Tb, Dy, and Y) are being considered as very critical by Europe, the United States, and Japan, but we forecast that in the medium term, only neodymium will remain a critical REE. This paper discusses the relationship between criticality and the Balance Problem and shows how this relationship influences the market for specific REEs.

Binder free vertical aligned (VA) CNT/sulfur composite electrodes with high sulfur loadings up to 70 wt% were synthesized delivering discharge capacities higher than 800 mAh g(-1) of the total composite electrode mass.

VOLUME I: Fundamentals, Operations and Catalysts FLUID DYNAMICS IN MICROCHANNELS Multiphase Flow Microfluidic Networks Boiling and Two-Phase Flow in Microchannels Microscale Flow Visualization Modeling of Microfluidic Devices MIXING IN MICROSYSTEMS Characterization of Mixing and Segregation in Homogeneous Flow Systems Passive and Active Micromixers Mixing and Contacting of Heterogeneous Systems HEAT/MASS TRANSFER Heat Transfer in Homogeneous Systems Transport Phenomena in Microscale Reacting Flows Fluid-Fluid and Fluid-Solid Mass Transfer MICROSTRUCTURED DEVICES FOR PURIFICATION AND SEPARATION PROCESSES Extraction Capillary Electrochromatography MICROSTRUCTURED REACTORS Homogeneous Reactions Heterogeneous Multiphase Reactions Photoreactors Microstructured Reactors for Electrochemical Synthesis VOLUME II: Devices, Reactions and Applications MICROREACTOR DESIGN, FABRICATION AND ASSEMBLY Silicon and Glass Microreactors Metallic, Steel, Ceramic and Plastic Microreactors BULK AND FINE CHEMISTRY Liquid- and Liquid-Liquid-Phase Reactions - Aliphatic Substitution Reactions Liquid- and Liquid-Liquid-Phase Reactions - Aromatic Substitution Reactions Liquid- and Liquid-Liquid-Phase Reactions - Addition and Elimination Liquid- and Liquid-Liquid-Phase Reactions - Coupling Reactions Liquid- and Liquid-Liquid-Phase Reactions - Oxidations and Reduction Gas-Liquid-Phase Reactions: Substitution Gas-Liquid-Phase Reactions: Addition Gas-Liquid-Phase Reactions: Reduction Gas-Liquid-Phase Reactions: Miscellaneous Reactions POLYMERIZATION Free Radical Polymerization Living Radical Polymerization Cationic Polymerization Polycondensation FUNCTIONAL MATERIALS Organic Particles and Pigments Inorganic Particles Polymer Particles Microencapsulates, Proteins and Lipids/Vesicles Oil-in-Water and Water-in-Oil Emulsions Double, Triple and Complex Multilayered Emulsions Microreactor Applications in the Consumer Goods Industry FUEL PROCESSING Application and Operation of Microreactors for Fuel Conversion Steam Reforming Partial Oxidation CO Clean-Up: Water Gas Shift and Methanation Reactions CO Clean-Up: Preferential Oxidation VOLUME III: System, Process and Plant Engineering MICROREACTOR SYSTEMS DESIGN AND SCALE-UP Structured Multi-Scale Process Systems Design and Engineering - The Role of Microreactor Technology in Chemical Process Design Reaction and Process System Analysis, Miniaturization and Intensification Strategies Principles and Guidelines for Selection of Microstructured Devices for Mixing and Reaction Catalyst Development, Screening and Optimization SENSING, ANALYSIS, AND CONTROL Microtechnology and Process Analytics Optical In-Line Spectroscopy in Microchemical Processes On-Line Monitoring of Reaction Kinetics in Microreactors Using Mass Spectrometry and Micro-NMR Spectroscopy Automation and Control of Microprocess Systems MICROREACTOR PLANTS: CASE STUDIES Industrial Microreactor Process Development up to Production Microreactor Plant for the Large-Scale Production of a Fine Chemical Intermediate: A Technical Case Study Development and Scale-Up of a Microreactor Pilot Plant Using the Concept of Numbering-Up Microstructures as a Tool for Production in the Tons per Hour Scale ECONOMICS AND ECO-EFFICIENCY ANALYSES The Economic Potential of Microreaction Technology Life Cycle Assessment of Microreaction Technology Versus Batch Technology - A Case Study Exergy Analysis of a Micro Fuel Processing System for Hydrogen ald Electricity Production - A Case Study

Recently, “smart” hydrogels with either shape memory behavior or reversible actuation have received particular attention and have been further developed into sensors, actuators, or artificial muscles.

Summary 1. Climate change in the subarctic is expected to influence vegetation composition, specifically bryophyte and lichen communities, thereby modifying litter decomposition rates and carbon (C) dynamics of these systems with possible feedbacks to climate. 2. In a 2‐year experiment, we investigated decomposition rates and chemical traits of 27 bryophytes, 17 lichens and 5 vascular plants in litter beds in subarctic Sweden. The majority of the sampled cryptogam species are widespread at higher northern latitudes. 3. Average 2‐year litter decomposition rates (exponential mass loss constant k ) of lichen (0.44 ± 0.01) and vascular plant (0.56 ± 0.03) species were higher than that of bryophytes (0.11 ± 0.01), while within main cryptogam taxa, species identity was an important determinant of mass loss rates. At cryptogam group level, 2‐year litter mass loss of Sphagnum was significantly lower than for non‐ Sphagnum mosses and liverworts. Within lichens, N 2 ‐fixing versus non‐N 2 ‐fixing lichens showed no variation in decomposability. 4. In a subset of the large species set, mass loss differed both among incubation environments (reflecting nutrient‐rich and poor birch forest and Sphagnum peatlands, respectively) and species. The pattern of mass loss across incubation environments was not consistent among cryptogam species. N 2 ‐fixing, in contrast to non‐N 2 ‐fixing lichens with lower nitrogen (N) levels displayed similar decomposition rates across incubation environments. Mass loss of non‐ Sphagnum mosses was correlated with initial N irrespective of incubation environment. 5. Litter mass loss of cryptogam taxa could be predicted very well from infrared spectra of the initial chemical composition of the species, by application of Fourier transform infrared using an attenuated total reflectance probe. The initial macronutrient concentrations (N, phosphorus, C and cations) and initial litter pH correlated less well. 6. Synthesis . We showed comprehensively that decomposition rates of bryophytes are generally lower than those of lichens and vascular plants. Among bryophyte or lichen species there is also great variation in litter decomposability which depends strongly on species‐specific chemistry. Our data will help predict changing land surface feedback to C cycles and climate in cold biomes by understanding long‐term climate effects on litter decomposability through shifting vegetation composition.

MoO_3−x displayed dramatically enhanced photo-thermal synergistic CO₂ reduction under simulate sunlight irradiation compared to MoO₃ due to the LSPR of MoO_3−x triggered by oxygen vacancies.

1908 in Spandau (Berlin) and took his degree in Physical Chemistry. He began his initial studies in the area of energetic compounds in connection with his Doctor's degree in 1931 at Professor Bodenstein's Institute in Berlin with a paper on the enthalpy of formation and thermal decomposition of hydrazoic acid. After taking his Doctor's degree, he entered the Dynamit Nobel Company in 1934 as assistant to Dr. Ph. Naoum. He worked there from 1936 -1945 on the development of pourable ammonium nitrate explosives and on hollow charges. After the WWII he accepted a position as scientific adviser to the Government of Argentina in Buenos Aires. He returned to Germany in 1954

Polymersomes as synthetic analogues of liposomes appear frequently in relevant literature as promising candidates for a wide range of different applications including drug delivery, theranostic multitools, and nanoreactors. In particular, as nanotransporters for nanomedical applications in vivo, requirements concerning the reproducible manufacturing and reliable size control are extremely high. This Perspective highlights the importance of size control especially in the context of nanomedicine and gives an overview of the theoretical background of amphiphilic self-assembly leading to different preparation methods, where their feasibility of controlling polymersomes’ size is discussed.

Development of an ideal methane activation catalyst presents a trade-off between stability and reactivity of the active site that can be achieved by tuning the transition metal cation, active site motif and the zeolite topology.

Due to the recent widespread application of nanomaterials to biological systems, a careful consideration of their physiological impact is required. This demands an understanding of the complex processes at the bio-nano interface. Therefore, a comprehensive and accurate characterization of the material under physiological conditions is crucial to correlate the observed biological impact with defined colloidal properties. As promising candidates for biomedical applications, two SiO2-based nanomaterial systems were chosen for extensive size characterization to investigate the agglomeration behavior under physiological conditions. To combine the benefits of different characterization techniques and to compensate for their respective drawbacks, transmission electron microscopy, dynamic light scattering and asymmetric flow field-flow fractionation were applied. The investigated particle systems were (i) negatively charged silica particles and (ii) poly(organosiloxane) particles offering variable surface modification opportunities (positively charged, polymer coated). It is shown that the surface properties primarily determine the agglomeration state of the particles and therefore their effective size, especially under physiological conditions. Thus, the biological identity of a nanomaterial is clearly influenced by differentiating surface properties.

The design and development of multifunctional polymer capsules with controlled chemical composition and physical properties has been the focus of academic and industrial research in recent years. Especially in the biomedical field, the formulation of novel polymer-based encapsulation systems for the early-stage disease diagnostic and effective delivery of bioactive agents represent one of the most rapidly advancing areas of science. The stimuli-responsive release of cargo molecules from the carrier gains remarkable attention for in vitro and in vivo delivery of contrast agents, genes, and pharmaceutics. In this Review, the current status and the challenges of different polymer-based micro- and nanocapsule formulations are considered, emphasizing on their potential biological application as carriers for specific drug targeting and controlled release upon applying of external stimulus.

Optimisation of manufacturing process parameters requires resource-intensive search in a high-dimensional parameter space. In some cases, physics-based simulations can replace actual experiments. But they are computationally expensive to evaluate. Surrogate-based optimisation uses a simplified model to guide the search for optimised parameter combinations, where the surrogate model is iteratively improved with new observations. This work applies surrogate-based optimisation to a composite textile draping process. Numerical experiments are conducted with a Finite Element (FE) simulation model. The surrogate model, a deep artificial neural network, is trained to predict the shear angle of more than 24,000 textile elements. Predicting detailed process results instead of a single performance scalar improves the model quality, as more relevant data from every experiment can be used for training. For the textile draping case, the approach is shown to reduce the number of resource-intensive FE simulations required to find optimised parameter configurations. It also improves on the best-known overall solution.

Abstract The nitrile imine‐mediated tetrazole‐ene cycloaddition reaction (NITEC) is introduced as a powerful and versatile conjugation tool to covalently ligate macromolecules onto variable (bio)surfaces. The NITEC approach is initiated by UV irradiation and proceeds rapidly at ambient temperature yielding a highly fluorescent linkage. Initially, the formation of block copolymers by the NITEC methodology is studied to evidence its efficacy as a macromolecular conjugation tool. The grafting of polymers onto inorganic (silicon) and bioorganic (cellulose) surfaces is subsequently carried out employing the optimized reaction conditions obtained from the macromolecular ligation experiments and evidenced by surface characterization techniques, including X‐ray photoelectron spectroscopy and FT‐IR microscopy. In addition, the patterned immobilization of variable polymer chains onto profluorescent cellulose is achieved through a simple masking process during the irradiation.

reduction reaction, reported in the literature. However, almost none of them entered the stage of application yet. Likewise, the reports on process engineering inadequately address the utilization of these catalysts, as well as electrode and cell concepts, that might be suitable for the market. Evidently, a closer collaboration between chemists and engineers from industry and academia is desirable to speed up the development of these disruptive technologies. Herein, we elucidate the critical parameters and highlight the necessary aspects to accelerate the development of industrially relevant catalysts capable of fulfilling the forthcoming challenges related to energy conversion and storage. The aim of this Perspective, composed by industrial and academic partners, is to critically question current undertakings and to encourage researchers to strike interdisciplinary research pathways.

A techno-economic model was developed to investigate the influence of components on the system costs of redox flow batteries. Sensitivity analyses were carried out based on an example of a 10 kW/120 kWh vanadium redox flow battery system, and the costs of the individual components were analyzed. Particular consideration was given to the influence of the material costs and resistances of bipolar plates and energy storage media as well as voltages and electric currents. Based on the developed model, it was possible to formulate statements about the targeted optimization of a developed non-commercial vanadium redox flow battery system and general aspects for future developments of redox flow batteries.