c6&70 containing soot was produced by arc-vaporization of graphite. The chromatographic separation of soot yielded fairly pure Cm and C70 samples. High-resolution FT-Raman spectra of c 6 0 and C70 specimen as well as c 6 0 and C70 solutions including polarization measurements are recorded. Compared to the spectrum of solid c60, some Raman bands of the Cm solution change their position and shape. Even the purest commercial C~O samples contain solvent inclusions (impurities) in the order of some percentage. The chromatographic separation combined with Raman polarization measurements of solutions allows an evaluation of the fundamental vibrations of the c 6 0 molecule. Its assignment, in accordance with the group theoretical expectation, is proposed. The existence of small amounts of c 6 0 isomers (symmetry, e.g., Czvr D z~, D z~) in icosahedral c 6 0 (Zh) is affirmed based on the polarization measurements. For C70 the most extended set of Raman frequencies is presented.

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Surface hydrophobicity of composite films containing polymer and nanoparticles has been studied as a function of composition. We show that the hydrophobicity can be tuned by adjusting the amount of particles in the two-component system. A sharp transition from a polymer-rich surface to a nanoparticles-rich surface was observed with increasing mass fraction of particles in spin-coated thin films. Water drops on the films did not slide down even at tilt angles of 90 degrees . Contact angle hysteresis increased with the mass fraction of particles indicating that the surface roughness increased as the surfaces remained in the Wenzel regime. Contact angle hysteresis data were quantitatively consistent with predictions of a recent theory.

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A simple kinetic model describing the molecular gas phase reactions during the formation of fumed silica (AEROSIL ) was developed. The focus was on the formation of molecular SiO 2 , starting from SiCl 4 , hydrogen and oxygen. Wherever available, kinetic and thermodynamic parameters were taken from the literature. All other parameters are based on quantum chemical calculations. From these data, an adiabatic model for the combustion reaction has been developed. It was found that a significant amount of molecular SiO 2 forms after about 0.1 and 0.6 ms at Die Verbrennung von SiCl 4 in heissen O 2 /H 2-Flammen Inhaltsübersicht. Zur Beschreibung der molekularen Reaktionen in der Gasphase während der Herstellung von pyrogenem Siliciumoxid (AEROSIL ) wird ein einfaches kinetisches Modell entwikkelt. Gegenstand der Arbeiten ist die Bildung von molekularem SiO 2 , ausgehend von SiCl 4. Kinetische und thermodynamische Parameter, die in der Literatur nicht zur Verfügung stehen, werden mit Hilfe von quantenmechanischen Methoden berechnet. Im Rah