Application of a new separation analyzer for the characterization of dispersions stabilized with clay derivatives

The performance of a newly developed separation analyzer is demonstrated by characterization of the sedimentation kinetics and the swelling behavior of organoclays in binary solvent mixtures (toluene/cyclohexane) as well as by investigation of oil-in-water and water-in-oil emulsions stabilized by clay derivatives. The automatic measuring system - LUMiFuge 114 - is based on a special centrifuge with an integrated optoelectronic sensor system which allows the measuring of spatial and temporal changes of light transmission during the rotation in a variable centrifugal field (12-1200g). By using the new device a fast and reproducible characterization of settling behavior and dispersion stability was possible. Moreover, the evaluation of the long-term stability of samples with high separation stability as well as of the heterogenity of the separation process, the sample transparency and the elasticity of the sediment as a function of alternating centrifugal force could be carried out.