Due to their low vapor pressures, nonflammability, high thermal stabilities, and excellent tribological properties ionic liquids (ILs) are highly attractive lubricant base oils and additives. However, for practical applications of ILs in lubrication, two requirements are often limiting, the required miscibility with standard mineral oils (≥5 wt %) and the complete absence of corrosive halide ions in the ionic liquid. Moreover, the need for full compatibility with standard oil additives reduces the number of potential IL-based lubricant additives even further. In this contribution, an economic halide-free synthesis route to oil-miscible ionic liquids is presented, and very promising tribological properties of such ILs as base oil or additive are demonstrated. Therefore, sliding tests on bearing steel and XPS analysis of the formed surface films are shown. Corrosion test results of different bearing metals in contact with our halide-free ILs and (salt) water prove their applicability as real life lubricants. In the sustainable chemistry and engineering context, we present a halide-free design approach for ionic performance chemicals that may contribute to significant energy savings due to their enhanced lubrication properties.

A sensor system for fast analysis of synthesis gas (mixtures of CO and H(2)) is proposed and characterized. The system is based on spontaneous Raman scattering, which enables simultaneous concentration measurements of all relevant species. For typical synthesis gas applications, this system has to face large variations of temperature and pressure. In addition, strong fluctuations in mixture composition may occur, which lead to rather inconvenient signal intensities. In this paper, we describe a low resolution spectrometer designed to function as a synthesis gas sensor and characterize pressure and temperature effects on concentration measurements. In addition, the use of different spectral ranges and calibration strategies is investigated in view of measurement accuracy and precision.

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Motivation und Problemstellung Die Energie- und Ressourceneffizienz technischer Produkte besitzt sowohl im Bewusstsein der Bevölkerung und damit der Nutzer bzw. Käufer als auch aufgrund regulatorischer Anforderungen durch Behörden eine immer größere Bedeutung. Knapper werdende Rohstoffe sowie eine internationale Klimaschutzpolitik erzwingen die Reduzierung von klimarelevanten Gasen und somit vor allem der CO2-Emissionen. Was dies konkret bedeutet, soll am Beispiel des Automobils aufgezeigt werden: etwa 20 % des CO2- Ausstoßes sind in Deutschland im Bereich Verkehr zu verorten wovon wiederum 84 % auf den Straßenverkehr zurückgehen [1]. Über Deutschland hinaus spielt der Straßenverkehr aber auch weltweit eine wichtige Rolle bei den Emissionen. Allein die Zahl der PKW steigt tendenziell von aktuell 0,9 Milliarden [2] durch den Aufstieg der Schwellenländer bis 2035 auf 1,7 Milliarden und bis 2050 auf 2-3 Milliarden PKW an [3, 4]. Für die dabei in Zukunft anzutreffenden Antriebs...

An ever increasing mobility and a shortage of resources lead to restrictive politically driven limits for fuel consumption as well as an increasing demand of customers for efficient vehicles. Though electrification of cars proceeds, combustion engines will play an important role for conventional and hybrid concepts within next decades. Thus, for a contribution to increasing energy efficiency of vehicles it is vital to trace sources of friction losses and to identify possibilities for friction reduction in combustion engines. Therefore, the follower as a main contributor to friction losses in valve trains was chosen as a demonstrator for friction reduction effects by microstructured components. However, the realization of theoretically advantageous microstructures with filigree geometries is challenging for manufacturing technologies. The present study focuses on the elaboration of a technological basis for a repeatable production of components with microstructured surfaces by a combined cup backward extrusion micro coining process, coping with the demands of large-lot production. For realization of a high accuracy the influence of friction on geometry of microstructured components was investigated. In addition, running-in of components is decisive for final geometry and tribological behavior of microstructured surfaces and hence considered as well.