Adsorbed Counterions and Lateral Diffusion mHz—kHz Range

Schwartz (1962) proposed a model with a tightly bound layer of adsorbed counterions on the sphere surface to explain the high permittivity increment found (hundreds of 8q) in a suspension of colloidal particles. Diffusion, and not migration, may govern ionic motion in a double layer. Diffusion processes are not necessarily exponential, but as an 

In Schwartz s theory, the ions were bound to the double layer and lateral motion within it. A theory is also possible allowing ions to enter or leave the layer from the hulk. 

Takashima (1989) deduces the expression for the dielectric increment of a suspension of long cylinders by transforming the relations for ellipsoids from rectangular to cylindrical coordinates  

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