Charakterisierung von Silika (Aerosil) Hydrosolen durch Photonenkorrelationsspektroskopie / Characterization of Silica(Aerosil)Hydrosols by Photon Correlation Spectroscopy

Abstract

Abstract The diffusion of silica(Aerosil)-hydrosols has been studied by photon correlation spectroscopy. For data analysis the method of cumulants, proposed by Koppel, was used. Effects of charge and hydratation of the silica particles and their complicated aggregated structure required an extrapolation to the solconcentration cs = 0 and the scattering angle θ = 0. The described data analysis combined with the methodical proceeding - using Aerosil aggregates as a model system - shows how to evaluate the diffusion coefficient and its normalized variance. These data of characterization are important for many kinds of aggregated particles in technical applied dispersions.