The addition of inorganic spherical nanoparticles to polymers allows the modification of the polymers physical properties as well as the implementation of new features in the polymer matrix. This review article covers considerations on special features of inorganic nanoparticles, the most important synthesis methods for ceramic nanoparticles and nanocomposites, nanoparticle surface modification, and composite formation, including drawbacks. Classical nanocomposite properties, as thermomechanical, dielectric, conductive, magnetic, as well as optical properties, will be summarized. Finally, typical existing and potential applications will be shown with the focus on new and innovative applications, like in energy storage systems.

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We are gratefully acknowledged to the Stifterverband Metalle and the Deutsche Forschungsgemeinschaft for financial support. Additionally we wish to thank the BASF AG, Hu¨ls AG, Hoechst AG and Degussa AG for delivering materials and the Ciba Additive GmbH for the kind donation of the photoinitiators. We also wish to thank our colleagues, especially Mr. P. Holzer and the members of the galvanic team of the corrosion division of our institute (IMFIII/KOR) and microparts GmbH for the electroplating and helpful support.Abstract Injection molding technology and its different modifications represent established processes for manufacturing polymer products with high accuracy in large scale production. Enhanced machine and tool technologies like evacuation units and special temperization systems have already been adapted to the molding of microstructures with high aspect ratios. Cycle times are actually in the range of minutes and depend on the geometry of the microstructures and the materials used. Based on injection molding of lost plastic microforms new processes for the manufacturing of ceramic or metal microstructures are being developed.

In this work, a 3D printed polymer–metal soft-magnetic composite was developed and characterized for its material, structural, and functional properties. The material comprises acrylonitrile butadiene styrene (ABS) as the polymer matrix, with up to 40 vol. % stainless steel micropowder as the filler. The composites were rheologically analyzed and 3D printed into tensile and flexural test specimens using a commercial desktop 3D printer. Mechanical characterization revealed a linearly decreasing trend of the ultimate tensile strength (UTS) and a sharp decrease in Young’s modulus with increasing filler content. Four-point bending analysis showed a decrease of up to 70% in the flexural strength of the composite and up to a two-factor increase in the secant modulus of elasticity. Magnetic hysteresis characterization revealed retentivities of up to 15.6 mT and coercive forces of up to 4.31 kA/m at an applied magnetic field of 485 kA/m. The composite shows promise as a material for the additive manufacturing of passive magnetic sensors and/or actuators.

With respect to rapid prototyping of ceramic components, there are known only a few processes (stereo lithography, binder jetting). In this work, a new process chain is described in detail, showing that ceramics can be printed in a very cost-efficient way. We developed a ceramic–polymer composite as filament material that can be printed on a low-cost fused filament fabrication (FFF) desktop printer, even with very small nozzle sizes enabling very small geometric feature sizes. The thermal post-processing, with debinding and sintering, is very close to the ceramic injection molding (CIM) process chain.

Starting from commercially‐available, polymer‐based reactive resins like acrylates or unsaturated polyesters, a systematic investigation was carried out as to the influence organic dopants like phenanthrene and its derivatives have on the optical and thermal properties of the mixtures resulting from curing to the final thermoplastic polymer. The refractive index of PMMA at 633 nm can be increased, starting from 1.49 for the pure polymer, up to a value of around 1.55, and, in the case of the polyester, from 1.565 up to 1.6. The transmittance in the visible range is slightly affected at a lower dopant concentration of up to 10 wt.‐%, and remains better than 80% for a sample with a thickness of 1 mm, in the range between 500 and 800 nm. An unwanted side‐effect of larger dopant concentrations is to lower the glass transition temperature significantly.magnified image

To unleash the full potential of white organic light-emitting diodes (OLEDs) as large-area light sources, guided optical modes have to be efficiently outcoupled, which calls for internal extraction layers (IELs) that can be easily integrated into a scalable manufacturing process. To realize such IELs, we developed a high refractive index scattering polymer:TiO2-nanoparticle mixture that can be deposited onto a large area by using the cost-effective screen-printing method. We exploited this approach to produce a 10 μm thick IEL covering the exact area of active pixels distributed over a 15 × 15 cm2 glass substrate. By optimizing the initial mixture composition, we achieved screen-printing-compatible rheological properties as well as tailored light scattering and transmission over the visible spectrum. The spatial homogeneity of those optical properties was obtained by additional substrate treatments to improve the wetting behavior and to allow reflow after printing. The devices were finalized by depositing a high-efficiency white OLED stack atop the IEL. We demonstrated a luminous efficacy increase up to 56% due to the scattering layer. The IEL also ensured a Lambertian emission profile without any angular color shift.

In this empirical study, five electrolyte additives, namely, lithium bis(oxalato) borate, lithium difluoro(oxalato) borate, 1-vinyl-1,2,4-triazole, 1-vinyl imidazole and dimethyl-2,5-dioxahexane dioate are described and compared regarding their effect in LNMO//graphite cells. The additives were selected from a preliminary study of 59 potential additives. The basis electrolyte mixture is DMC/EC + 1 M LiPF 6 (LP30) for all cells. All additives are able to enhance the cycle life at room temperature and at elevated temperatures (50°C) significantly compared to the non-additive electrolyte blend (basis electrolyte). The cell enhancement is discussed based on the solid-electrolyte interface (SEI) and metal-ion content on anode side. The aim of the study is to suggest promising already known as well as new additives that are able to overcome the issue of rapid capacity fading of LNMO-based cells when the cells are cycled up to 4.8-5.0 V vs. Li/Li + , especially at higher temperatures.