LYOTROPIC EFFECT IN SURFACE-CHARGE, ELECTROKINETICS, AND COAGULATION OF A RUTILE DISPERSION

Potentiometric, electrokinetic, and coagulation experiments with a rut ile dispersion in the pH region above the point of zero charge exhibit an ''inverse'' lyotropic sequence for counterions: Li+ > K+ > Cs+. Th e potentiometric and electrokinetic data were interpreted by a surface complexation model assuming the Stern-Gouy-Chapman structure of the i nterfacial layer, which yielded the values of inner layer capacitances , C, and the intrinsic equilibrium constants, K(ass)0, characterizing the specificity of each counterion. These parameters were used to expl ain the order of lyotropic sequences in the adsorption, coagulation, a nd electrokinetic phenomena.