Digitally controlled inkjet printing technology has attractive features for the production of catalyst coated membranes (CCM) for application either in electrolysers or in fuel cells. There are a number of unique features: pattern like coating for effective use of expensive materials like platinum or iridium, direct deposition onto membrane material, non-impact printing, easy change of pattern design, and ability to generate catalytic gradients. Employing inkjet printing technology enables the manufacturing of catalytic layers as well as other components. The challenges are to evaluate process-compatible inks as well as processing parameters. / Die digital gesteuerte Inkjetdrucktechnologie hat attraktive Eigenschaften für die Herstellung von katalysatorbeschichteten Membranen (CCM), die entweder in Elektrolyseuren oder in Brennstoffzellen eingesetzt werden. Es gibt eine Reihe einzigartiger Merkmale: mustergenaue Beschichtung für den effektiven Einsatz teurer Materialien wie Platin oder Iridium, direkte Bedruckung des Membranmaterials, berührungsfreies Drucken, einfache Änderung des Druckdesigns und die Fähigkeit, katalytische Gradienten zu erzeugen. Der Einsatz der Inkjetdrucktechnologie ermöglicht die Herstellung von katalytischen Schichten und anderen Komponenten. Die Herausforderungen bestehen darin, prozesskompatible Tinten sowie Verarbeitungsparameter zu evaluieren.

Switchable hydrogel-layered composite membranes can be used for the analysis of particle size distributions. This functionality is provided by pores with controllable diameter. In order to obtain a device that can be used to measure the cell size distribution in native biological samples, lots of switchable pores are required. In the current work, we model and simulate the mechanical behavior of active composite membranes with switchable pores. This is done in order to find the maximum number of pores that can be integrated into a membrane without cross-influencing effects on the actuation of the pores. Therefore, we investigate (1) the interaction of active pores inside the multifunctional composite and (2) the membrane bending under microfluidic pressure load. We show that through miniaturization, sufficient pores can be added to a permeation control membrane for processing native blood samples. The envisioned device allows a parallelized measurement of cell sizes in a simple lab-on-a-chip setup.

Die vorliegende Arbeit beschäftigt sich mit der Terminologie von Stetigförderern im Deutschen und Französischen. Sie besteht aus drei Teilen, dem fachlichen Teil, dem translatorischen Teil und dem Glossar. Im ersten Teil soll in das Fachgebiet der Stetigförderer eingeführt werden. Dabei wird zuerst ein Einblick in die Geschichte der Stetigförderer gegeben, anschließend werden wesentliche Begriffe definiert und einige Möglichkeiten der Klassifizierung vorgestellt. Danach folgt die Beschreibung der einzelnen Förderer, die zur besseren Vergleichbarkeit stets die gleiche Struktur aufweist. Der zweite Teil befasst sich mit sprachwissenschaftlichen und translatorischen Faktoren der fördertechnischen Terminologie. Anfangs werden einige Grundfragen der Terminologiearbeit angesprochen, hiernach werden drei konkrete sprachliche Themen an deutschen und französischen Beispielen aus dem Glossar analysiert: die Benennungsbildung, die Motivation der Benennungen sowie die Zuordnung von Benennung und Begriff. Dabei sollen sprachliche Tendenzen in der deutschen und französischen Terminologie der Stetigförderer aufgezeigt werden. Dies soll Sprachmittlern Hilfestellung bieten, im Bereich der Stetigförderer Benennungen korrekt zu verwenden bzw. selbst zu finden. Der dritte Teil umfasst das zweisprachige Glossar.

A straightforward, rapid method to create colloidally stable and brightly luminescent core/shell CdSe-based nanoplatelets (NPLs) with fluorescence quantum yields (QYs) up to 50% is demonstrated. A layer-by-layer deposition technique based on a two-phase mixture ‒ consisting of a nonpolar phase which includes the NPLs, and a saturated ionic polar phase ‒ to separate the reagents and hinder the nucleation of the shell material is used. The deposition of the first sulfur layer leads to a significant red-shift (by more than 100 nm) of the optical absorption and emission of the NPLs. Hence, by varying either the sulfur precursor content or the reaction time one can precisely and continuously tune the absorption and emission maxima from 520 to 630 nm. This evolution of the absorption onset during the shell growth is explained quantitatively using density-functional theory and atomistic statistical simulations. The emission can be further enhanced by exposure of the NPL solution to ambient sunlight. Finally, it is demonstrated that the core/shell NPLs can be transferred from the organic solution to aqueous media with no reduction of their QY that opens the door to a broad range of practical applications.

Textile high-performance filament yarn subjected to extremely high thermal loads can be found in various technical application fields. Besides the mechanical loads, textile fiber materials have to also satisfy high safety requirements in these applications with respect to thermal loads. Some of the main fields of application in the field of mechanical engineering are turbines, drive devices, rocket components and fire protection coatings. Textile grid-like structures are also being increasingly used in civil engineering as reinforcements (textile concretes). The design and development of textile structures for these applications demands studying and acquiring the material behavior under high thermal loads. Neither sufficient data nor standardized testing methods have been extensively achieved for evaluating the tensile characteristics of filament yarns under thermal influences. Hence, studying the thermal behavior of these yarns, which are used as input material for the reinforcing structures, is essential. The impact of the standard atmospheric condition on the oxidation behavior of the yarns, as in the case of carbon filament yarns and their influence on the physicochemical and tensile mechanical properties, have to be studied as well. This paper aims to address this issue and provides an insight into the current research about the development and realization of a novel test stand and the subsequent study of tensile mechanical behavior for textile high-performance fiber material under extreme thermal loads together with their physicochemical behavior.

The aim of this research is to develop a wet-chemical silvering method for a three-dimensional (3D) textile material made of polyethylene terephthalate (PET) to prevent and eliminate biological contaminants in drinking water and other liquid-containing systems. Three-dimensional textile fabrics are particularly well-suited as silvered disinfection materials in water systems, because they have 3D structures, pressure-elastic textile design, and provide large contact areas. Furthermore, water can easily be passed through the structure. The developed wet-chemical procedures are based on aminosilane, which consists of at least two amine groups and is well-suited to form a silver diamine complex. The silvered textile material was coated with cationic silver. After the chemical reduction, the cationic silver turns into metallic silver on the surface of PET spacer fabrics. The surface morphology of silver-coated spacer fabrics was analyzed and the uniform silver layer on the PET fiber surface was found. X-ray diffraction and energy-dispersive X-ray spectroscopy analysis spectrums showed that the silver was immobilized on the PET fiber surface. The layer thickness and the silver amount were also determined. The silvered spacer fabrics can be used in sealing and/or cooling water systems; therefore, the silver ion release in water was analyzed. Furthermore, textile physical tests for the measurement of breaking force and elongation were carried out. No significant change in breaking force and elongation was observed after silvering of PET spacer fabric.

A novel laser light-sensitive yarn based on a thermoplastic polyester–urethane (TPU) has been prepared and analyzed. Since the thermosensitive shape memory polymer yarn (SMP yarn) has been functionalized using nanoscale heat sources exhibiting light-induced heat generation, the yarn is capable of an optically triggered shape memory effect (SME). For this purpose gold nanorods (GNR) have been employed. In addition to the incorporation of GNR into the yarn, a coating of GNR on the yarn is also proposed, applied by a semi-continuous layer-by-layer (LBL) technique. The SME of the functionalized yarns can be triggered either thermally or optically and has a strain recovery of almost 100%. The light-induced SME is triggered by a low-powered laser (808 nm, 2 W for a GNR-incorporated and 1W for a GNRcoated TPU yarn). A reference yarn without GNR showed no significant effect. An adaptive structure featuring a SMPyarn backed shape memory effect has been proposed and demonstrated.

Traumatic rupture of the anterior cruciate ligament (ACL) can cause local destabilization and loss of mobility. Reconstruction using engineered ACL grafts is rarely successful due to sub-optimal material choice and mechanical performance. Thus, the presented work demonstrates the fabrication of various embroidered single- and bi-component scaffolds made of two commercially available monofilament threads (polydioxanone, poly(lactic acid-co-ɛ- caprolactone)) as well as a novel melt spun poly(L-lactic acid) multifilament and their mechanical analysis by tensile tests and under cyclic loading. Selected scaffolds, adjusted by material composition and textile parameters, revealed a load–strain behavior comparable to native lapin ACL tissue exhibiting a sufficient amount of elastic deformation within the toe-region of 1.7%, scaffold stiffness of 123 N/mm and adequate maximum tensile load (300 N) and strain (20%). Therefore, the design of resorbable embroidered bi-component scaffolds represents a promising approach to replace artificial non-resorbable ligament grafts and allows for innovative tissue engineering strategies.

Non-crimp fabrics (NCFs), especially multi-axial warp-knitted fabrics, are used as reinforcement materials for fiberreinforced composites. The manufacturing of multi-axial warp-knitted fabrics by a conventional stitch bonding process to produce NCF has several disadvantages, such as filament damage, low production speed, yarn disorientation, etc. In order to overcome the existing limitations, the idea of using an adhesive binder to attach the fabric layers is a promising approach, so that the use of stitching yarns can be eliminated. The fundamental investigations presented in this paper show that the selection of the binder material has a major influence on the parameters of the textile products. Whereas the tested hotmelt adhesives offer a short curing time and a small but nevertheless sufficient bonding strength between bonded yarns, the tested reactive adhesives show a bonding strength up to 10 times higher, but at a considerably longer curing time. The reason for the different bonding strength is identified in the different penetration into the yarns. The experiments also show a significant influence of the fiber type and sizing, which needs to be taken into account when selecting fabric binders.

Carbon fiber (CF) must be protected from thermal oxidation for high temperature application because of its low thermo-oxidative stability above 450°C in air. CF is now increasingly being used as a reinforcing material in the construction industry. A thermal and oxidation resistant coating is necessary for CF-reinforced concrete (CFRC) composites in order to satisfy a high level of safety standard in the case of fire. New types of pre-ceramic coatings, such as Tyranno® polymer (Si–Ti based pre-ceramic) and SiO₂ sol–gel, have been deposited on CF filament yarn by means of a wet chemical continuous dip coating method. The results of surface analyses, e.g. scanning electron microscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy, showed the changes in topographical properties of CF caused by the coatings. Thermogravimetric analysis proved that the high temperature (up to 800°C) oxidation stability of CF was considerably improved due to the coatings. Tensile test results indicated that the strength of CF yarn at 20°C was increased by up to 80% with the coatings. Thermo-mechanical properties were also enhanced up to 600°C. CF yarn retains its original strength and elasticity modulus, i.e. the stiffness at 700°C, with a Tyranno® polymer coating.