Publications by authors named "S Roitsch"

Hypothesis: In the phase diagram of the system HO/NaCl - AOT (sodium bis(2-ethylhexyl) sulfosuccinate) a homogeneous L channel can be detected at T = 25 °C as a function of the surfactant and the NaCl mass fraction. Our hypothesis is that a structural transition from a sponge-like to an onion-like structure occurs in this channel.

Experiments: We (a) determined the relevant part of the phase diagram, (b) carried out electrical conductivity and viscosity measurements, (c) visualized the nanostructure with freeze-fracture electron microscopy (FFEM) and freeze fracture direct imaging (FFDI), (d) determined the characteristic length scales from Small Angle Neutron Scattering (SANS) curves.

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Tunable aryl alkyl ionic liquids (TAAILs) are ionic liquids (ILs) with a 1-aryl-3-alkylimidazolium cation having differently substituted aryl groups. Herein, nine TAAILs with the bis(trifluoromethylsulfonyl)imide anion are utilized in combination with and without ethylene glycol (EG) as reaction media for the rapid microwave synthesis of platinum nanoparticles (Pt-NPs). TAAILs allow the synthesis of small NPs and are efficient solvents for microwave absorption.

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In this study, we present the facile formation of platinum nanoparticles (Pt-NPs) on reduced graphite oxide (rGO) (Pt-NP@rGO) by microwave-induced heating of the organometallic precursor ((MeCp)PtMe in different tunable aryl alkyl ionic liquids (TAAIL). In the absence of rGO, transmission electron microscopy (TEM) reveals the formation of dense aggregates of Pt-NPs, with primary particle sizes of 2 to 6 nm. In contrast, in the Pt-NP@rGO samples, Pt-NPs are homogeneously distributed on the rGO, without any aggregation.

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The composite of the metal-organic framework (MOF) Ni(Fe)-MOF-74 and the highly conductive carbon material ketjenblack (KB) could be easily obtained from the in-situ MOF synthesis in a one-step solvothermal reaction. The composite material features a remarkable electrochemical oxygen evolution reaction (OER) performance where the overpotential at 10 mA/cm and the current density at 1.7 V are recorded as 0.

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The non-trivial topology of three-dimensional topological insulators dictates the appearance of gapless Dirac surface states. Intriguingly, when made into a nanowire, quantum confinement leads to a peculiar gapped Dirac sub-band structure. This gap is useful for, e.

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