Here we report the experimental results of the general wetting behavior of an oil-based ferrofluid and a water-based magnetic paint droplet on a hydrophobic surface under the effect of an external magnetic field. By increasing the magnetic field in the vertical direction, the height of the oil-based ferrofluid droplet increases while the width decreases; on the contrary, under the same circumstances, the height of the water-based magnetic paint droplet decreases whereas the width increases. The wetting behavior of the oil-based ferrofluid and the water-based magnetic paint droplets is evaluated as a function of the contact angle, contact line diameter, and hysteresis curve alterations. Conclusively, a general explanation is given for the contrary behavior of both liquids, and some application processes for future implementations are introduced.

This study reports the behavior of the compounds BF3·D (with D = dimethyl carbonate, ethylene carbonate, ethyl methyl carbonate, propylene carbonate) as electrolyte additives in Li[Ni0.33Co0.33Mn0.33O2]/graphite cells with LiPF6 (1 M) in EC:EMC (3:7 wt%) as electrolyte. The adducts were prepared from gaseous BF3 with the corresponding carbonates in a simple Lewis acid base reaction and fully characterized (FT–IR and NMR spectroscopy, single crystal X-ray diffraction). The electrochemical behavior of the additives was examined at concentrations of 1 wt% and 0.25 wt% added to the electrolyte. Electrochemical impedance spectroscopy of cells with 1 wt% additive, display a significantly lower cell impedance than cells without additive, but also a slightly decreased capacity. To combine the high capacity retention with a low cell impedance the concentration of the additive was reduced. Thus, cell testing with 0.25 wt% additive incorporated with the electrolyte showed no difference in capacity retention after 55 cycles at 25 °C, but had lower cell impedance. The rate-performance test shows a higher capacity retention for cells with additive at high C–rates. The surface chemistry of the electrodes was studied by X-ray photoelectron spectroscopy and suggests that the additives react on both electrodes (Li[Ni0.33Co0.33Mn0.33O2] and graphite) and improve the electrode interphases.

Twelve bromoaluminate based ionic liquids (ILs) were synthesized and characterized by IR, Raman, and NMR spectroscopy, as well as single crystal X-ray diffraction in part. Their principal physicochemical properties including melting points, conductivities, viscosities, and densities were determined and compared with related ILs. The influence of the cation and anion on the physicochemical properties are discussed. The [AlBr ] based salts are-with one exception-solid at room temperature, while the compounds based on the anion [Al Br ] are liquid at room temperature. The liquid salts show low viscosities (49-139 mPa s), medium to high conductivities (0.76-3.53 mS cm ) and high densities (1.82-2.04 g cm ) at 28 °C. Furthermore, we showed aluminum electrodeposition from Lewis acidic ILs based on AlBr and 1-hexyl-3-methylimidazolium bromide and investigated the stability range of various formulations.

Mixtures of AlX (X=Cl, Br) with 1-butylimidazole (BuIm) in various ratios were investigated. The mixtures were characterized by multinuclear ( H, Al, C, and N) NMR, IR, and Raman spectroscopy and in part by single-crystal X-ray diffraction. Depending on the molar fraction x(AlBr ) of the AlBr -based mixtures, the cationic aluminum complexes [Al(BuIm) ] and [AlBr (BuIm) ] , the neutral adduct [AlBr (BuIm)], as well as the anions Br , [AlBr ] , and [Al Br ] could be identified as the products of the symmetric and asymmetric cleavage of dimeric Al Br . Furthermore, there are hints at the formation of [AlBr (BuIm) ] or related cations. Comparison of the AlBr /BuIm system with AlCl -based mixtures revealed the influence of the halide: In contrast to AlBr , the trication [Al(BuIm) ] could not be detected as main product in a 1:6 mixture of AlCl and BuIm. Additionally, [AlCl (BuIm)] crystallizes from a mixture with x(AlCl )=0.60 at room temperature, whereas the corresponding AlBr -based mixture remains liquid even at +6 °C. Three AlBr -based mixtures are liquid at room temperature, whereas all other mixtures are solids with melting points between 46 and 184 °C. The three liquid mixtures exhibit medium to high viscosities (117 to >1440 mPa s), low conductivities (0.03-0.20 mS cm ), but high densities (1.80-2.21 g cm ). Aluminum could be successfully deposited from one of the neat Lewis acidic mixtures of the AlBr -based system.

The formation of simple non-classical silylium ions from [Me3Si]+ sources and alkenes or alkynes was investigated, but mainly oligomerization was observed. Yet, the reaction with MeCCMe led to a room temperature stable cyclobutenyl cation. DFT calculations suggest that a non-classical silylium ion intermediate was formed on the way to this product.

The aerothermal interaction of the combustor exit flow on the first vane row has been examined at the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt (Darmstadt, Germany). A baseline configuration of axial inflow and a variation of swirling combustor inflow have been studied. The nozzle guide vane (NGV) featured endwall cooling, airfoil film cooling and a trailing edge slot ejection as well as NGV-rotor wheel space purge flow. CO 2 is injected for coolant flow tracing. The results are compared to five hole probe (5HP) measurements. The experiments for the baseline configuration are accompanied by numerical simulations using a passive scalar tracking method to validate the results and study the propagation of the coolant flow. The endwall coolant injection is detected to influence the pressure losses in the NGV. It has an impact on the Trailing Edge (TE) coolant ejection as well. For swirling combustor inflow, increased NGV pressure losses and increased mixing of Rear Inner Discharge Nozzle (RIDN) coolant and main flow is observed. An influence of the clocking position of the swirler to the vane is detected. Additional losses within the NGV row can be assigned to the swirler by means of flow tracing.

An algorithm is presented generating a complete set of inlet boundary conditions for Reynolds-averaged Navier-Stokes computational fluid dynamics (RANS CFD) of high-pressure turbines to investigate their interaction with lean and rich burn combustors. The method shall contribute to understanding the sensitivities of turbine aerothermal performance in a systematic approach. The boundary conditions are based on a set of input parameters controlling velocity, temperature, and turbulence fields. All other quantities are derived from operating conditions and additional modelling assumptions. The algorithm is coupled with a CFD solver by applying the generated profiles as inlet boundary conditions. The successive steps to derive consistent flow profiles are described and results are validated against flow fields extracted from combustor CFD.

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