Influence of Nanoscale Surface Topography and Chemistry on the Functional Behaviour of an Adsorbed Model Macromolecule

The functional behaviour of a model macromolecule (fibrinogen) adsorbed at the nanofabricated solid‐liquid interface was found to be strongly influenced by the local topographic structure of the interface. Protein molecules bound at topographically structured surfaces (either chemically homogeneous or heterogeneous 40‐nm diameter and 10‐nm deep pits) were found to bind platelets significantly faster than uncoated substrates whereas proteins bound to flat (R_a 1 nm) substrates were not. During the initial interaction, the chemistry of the underlying substrate apparently does not affect the macromolecules' functional behaviour.     

Thermodynamik und Kinetik des chemischen Transports von Ge mit GeCl4

Thermodynamics and Kinetics of the Chemical Transport of Ge with GeCl₄ The chemical transport of germanium according to the reaction Ge + GeCl_4,g = 2GeCl_2,g has been investigated under different experimental conditions. Only for the case of large reaction volumes connected by a relatively long and narrow diffusion path the transport rate agrees with the calculated values obtained by the conventional model for diffusion between equilibrium spaces. For experiments with simple cylindrical ampouls(inner diameter 1.8cm, length 15 cm) it depends clearly upon the reaction conditions whether the inhibiting influence of kinetics or the increase in reaction rate by the thermal convection are dominating.     

Die Stabilität von gasförmigem GeS2

Stability of Gaseous GeS₂ For the reaction the ΔH°(298) = 33 kcal (138kJ) has been determined. This value has been obtained from chemical transport reactions as well as from mass spectrometric und thermogravimetric observations.     

Der chemische Transport von Cu,Ag, Au,Ru, Rh,Pd, Os,Ir, Pt unter Mitwirkung von Gaskomplexen. Al2Cl6, Fe2Cl6 oder Al2J6 als Komplexbildner

The Chemical Transport of Cu, Ag, Au, Ru, Rh, Pd, Os, Ir, Pt in the Presence of Al₂Cl₆, Fe₂Cl₆ or Al₂I₆, Causing Complex Formation Chemical transport experiments show, that the title elements (with exception of Os) in the presence of halide forming agents (HCl, Cl₂ or I₂ resp.) and of complex forming agents (Al₂Cl₆, Fe₂Cl₆ or Al₂I₆ resp.) give gaseous complex compounds with a remarkable stability. This leads to novel possibilities for the chemical transport of the elements and their compounds. The effect of complex formation can be predicted on the basis of qualitative thermodynamic considerations. The corrosion of the wall of the quartz ampoule at temperatures above 600°C by Al₂Cl₆/AlCl₃ is avoidable by the usage of Fe₂Cl₆/FeCl₃ instead of Al₂Cl₆/AlCl₃. Experiments in the system Pd/I₂, Al₂I₆ lead to the formation of crystals of Pd₂Al.     

Synthesis and rearrangement of functionalized dispiro [3.0.3.3]Undecanes - a new entry to [3.3.3]Propellanes1

The functionalized dispiro[3.0.3.3]undecanes 6 and 7 undergo cascade rearrangements to yield the [3.3.3]propellanes 15 and 11, respectively. The formation of 15 proceeds via the bicyclic enone 16.     

Modeling of the adsorption and desorption of CO2 on Cu/ZrO2 and ZrO2 catalysts

The interaction between carbon dioxide and two zirconia catalysts-a Cu/ZrO2 catalyst containing 34% copper and a pure ZrO2 catalyst-was studied by pulse adsorption and temperature-programmed desorption methods. Kinetic modeling by nonlinear regression was applied to acquire information on the adsorption and desorption of CO2 relevant in the synthesis of methanol from carbon dioxide. A model that included three types of adsorption sites described well the experimental data for both Cu/ZrO2 and ZrO2. The model assumed first-order kinetics and a Freundlich-type logarithmic dependence of adsorption enthalpy on surface coverage. The parameters of the model were well identified and were in the physically meaningful range. The results indicate that, at 30 degrees C, on both catalysts, carbon dioxide adsorbs reversibly on one type of site and irreversibly on two other types of sites.