Donor:Acceptor Janus Nanoparticle-Based Films as Photoactive Layers: Control of Assembly and Impact on Performance of Devices

Water-processable organic semiconductor nanoparticles (NPs) are considered promising materials for the next-generation of optoelectronic applications due to their controlled size, internal structure, and environmentally friendly processing. Reasonably, the controllable assembly of donor:acceptor (D:A) NPs on large areas, quality, and packing density of deposited films, as well as layer morphology, will influence the effectiveness of charge transfer at an interface and the final performance of designed optoelectronic devices.This work represents an easy and effective approach for designing self-assembled monolayers of D:A NPs. In this self-assembly procedure, the NP arrays are prepared on a large scale (2 × 2 cm²) at the air/water interface with controlled packing density and morphology. Due to the unique structure of individual D:A Janus particles and their assembled arrays, the Janus nanoparticle (JNP)-based device exhibits an 80% improvement of electron mobility and more balanced charge extraction compared to the conventional core–shell NP-based device. An outstanding performance of polymer solar cells with over 5% efficiency is achieved after post-annealing treatment of assembled arrays, representing one of the best results for NP-based organic photovoltaics. Ultimately, this work provides a new protocol for processing water-processable organic semiconductor colloids and future optoelectronic fabrication.     

Optimization of the Two- and Three-Dimensional Characterization of Rare Earth-Traced Deoxidation Products

Tracing by means of the light rare earths (REs), particularly La and Ce, is a state-of-the-art method used to track deoxidation products during the steelmaking process. Traced heterogeneous multiphase inclusions are analyzed using scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) to perform a 2D characterization. The sequential chemical extraction technique is implemented for a 3D investigation to determine traced particles’ actual sizes and shapes. The automated SEM/EDS measurement must be optimized since RE oxides appear brighter in the backscattered electron images due to their high atomic numbers. Therefore, two grayscales are implemented for the detection of RE-containing multiphase inclusions. Within this technique, individual RE-traced heterogeneous nonmetallic inclusions (NMIs) are counted as separate particles. Thus, the measured NMIs must be recombined, which is achieved using a self-developed MATLAB tool. The extracted particles are also analyzed by automated and manual SEM/EDS measurements to determine the 3D morphologies and sizes of traced NMIs.     

Air Cooling Martensites—The Future of Carbon Neutral Steel Forgings?

The air-hardening ductile forging steels belong to the third generation of advanced high-strength steels and achieve their final, martensitic microstructure simply by air cooling from the forging heat. The present conference paper reviews the 15 years of development, different alloying strategies, and metallurgical throwbacks like manganese embrittlement. Furthermore, the most recent results concerning microstructure, mechanical properties, and cyclic material behavior obtained from an industrial trial melt are discussed together with the implications of these results on the carbon footprint (CF) and their impact on the resource efficiency of forged steel components. It is demonstrated that the CF of a steel product needs to be discussed on different levels, as the material-, process-, and product-level contributions need to be considered. Furthermore, a case is made for new high-strength steels in the context of circular economy, as increase fatigue resistance enables lightweighting potentials.     

All-Printed Electrochromic Stickers

Displays are one of the most mature technologies in the field of printed electronics. Their ability to be manufactured in large quantities and at low cost has led to their recent uptake into the consumer market. Within this article this technology is extended to electrochromic display stickers. This is achieved using a recent reverse display architecture screen printed on textile and paper sticker substrates. The electrochromic stickers are comparable to plastic control substrates and show little performance difference even when adhered to curved surfaces. The electrochromic display technology is extended to sticker labels for authentication applications by patterning either the dielectric or the graphical layer. A proof-of-concept prototype emulating a wax seal on an envelope is presented to show that other colors can be implemented in this technology.     

AgCuS: A Single Material Diode with Fast Switching Times

Pnp-switchable semiconductor materials are capable of switching their electronic properties from p- to n-type conduction. Observed in the handful of discovered compounds, this behavior is usually accompanied by a temperature-dependent phase transition. During this transition, the dynamical rearrangement of a certain substructure enables the change of the predominant charge carrier type. Considering the immense demand for compact and flexible electronic components, one possible approach is the construction of unconventional one-compound diodes using these pnp-switchable materials. In this study, pnp-switchable AgCuS is applied to realize a functional one-compound diode. AgCuS is accessible in large quantities as bulk material in a simple and short timeframe. Featuring an addressable pnp-switch at 364 K, this material is suitable for diode generation and usage in varied applications. The diode properties of AgCuS devices are reported and illustrate its reversibility and flexibility for diode operation. The material is fully characterized with regards to its electrical and thermal properties, as well as its diode performance. Properties of AgCuS are discussed in relation to the pnp-switchable material Ag₁₈Cu₃Te₁₁Cl₃, which is successfully used to fabricate the first one-compound diode operating close to room temperature.     

Fostering knowledge sharing: Design principles for persuasive digital technologies in open innovation projects

Integrating knowledge is crucial for open innovation, and digital technologies can play a central role because they support knowledge sharing. In open innovation projects, in particular, little is known about the role of technology. Here, the individual behaviour of users is taken into account concerning the extent to which knowledge is shared. Therefore, persuasive technologies offer the potential to foster sharing. In particular, to facilitate the construction of future digital technologies, this study applies a design science research approach to create and analyse artefacts as a research contribution and develop design principles as a step towards a nascent design theory. We present insights from the design and application of three artefacts in different stages of open innovation processes. Results show that digital technologies can be used for various purposes: to build a common understanding, support design phases, communicate ideas and simplify the application of the technology for the user. Our research provides insights into the role of digital technologies for knowledge sharing in open innovation projects, and four design principles are found to facilitate the construction of future persuasive digital technologies for open innovation projects.     

Influence of Nozzle Parameters on Spray Pattern and Droplet Characteristics for a Two-Fluid Nozzle

In this study, a two-fluid nozzle, as, e.g., used in fluidized-bed or spray drying applications, is comprehensively characterized regarding the spray pattern and droplet size. To analyze the spray cone, the spray cone angle and the radial mass distribution of the nozzle were measured at varied liquid flow rate, spray air pressure, liquid insert bore diameter, and air cap position. Additionally, droplet size distributions were recorded at different spray settings. In general, the overall spray cone and single droplets are significantly influenced by the spray parameters, especially the spray air pressure, as well as the nozzle geometry.     

Elucidation of the Bridging Pattern of the Lantibiotic Pseudomycoicidin

Lantibiotics are post-translationally modified antibiotic peptides with lanthionine thioether bridges that represent potential alternatives to conventional antibiotics. The lantibiotic pseudomycoicidin is produced by Bacillus pseudomycoides DSM 12442 and is effective against many Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. While prior work demonstrated that pseudomycoicidin possesses one disulfide bridge and four thioether bridges, the ring topology has so far remained unclear. Here, we analyzed several pseudomycoicidin analogues that are affected in ring formation via MALDI-TOF-MS and tandem mass spectrometry with regard to their dehydration and fragmentation patterns, respectively. As a result, we propose a bridging pattern involving Thr8 and Cys13, Thr10 and Cys16, Ser18 and Cys21, and Ser20 and Cys26, thus, forming two double ring systems. Additionally, we localized the disulfide bridge to connect Cys3 and Cys7 and, therefore, fully elucidated the bridging pattern of pseudomycoicidin.     

Untersuchungen zur Oxidation von α-substituierten Styrolen. I. Reaktivität und Produktbildung bei der Oxidation von Styrol-Derivaten

Studies on the Oxidation of α-Substituted Styrenes. I. Reactivity and Formation of Reaction Products During the Oxidation of Styrene Derivatives The liquid phase oxidation of α-tert. -butyl-, α-bromo-, α-chloro-, and α-methyl styrene with pure oxygen was investigated in a closed apparatus in chlorobenzene solution and in presence of cumene and of cumene hydroperoxide in the temperature range 35–125°C. The product yields were determined gaschromatographically. The differences of the activation energies of the epoxide formation and the parallel reactions were calculated. They amount to 27–38 kJ/mol. The epoxide selectivity increases with increasing temperature and decreases with increasing concentration of cumene. Relative chain propagation constants related to the tertiary CH-bond of cumene were determined from cooxidation experiments.