Interaction of Latex colloids with Grimsel Granodiorite and its component Minerals
A. Filby1, M. Plaschke1, H. Geckeis1, Th. Fanghänel2
1Institut für Nukleare Entsorgung, Forschungszentrum Karlsruhe, Postfach 3640,
Joint Research Centre, Institute for Transuranium Elements,
Interaction of carboxylated fluorescent latex colloids with natural Grimsel granodiorite and some of its component minerals is studied by fluorescence microscopy. The experiments are carried out by varying the pH from 2-10 at constant ionic strength. In general, strong adsorption is observed at pH values close to or below the expected pHpzc of the mineral surface. In addition, the influence of Eu(III) on colloid adorption is investigated. Depending on pH a significant increase of colloid adsorption is observed with relatively high Eu(III) concentrations, whereas comparatively lower Eu(III) concentrations have no obvious effect on colloid adsorption neither on single minerals nor on the Grimsel granodiorite.