ELECTROOPTIC INVESTIGATION OF OXIDE SUSPENSIONS - SURFACE-CHARGE SIGN REVERSAL THROUGH SPECIFIC ADSORPTION

Conclusions present in previous papers on the nature of low-frequency electro-optic effects are verified for more drastic variations in the particle double electric layer. The effects are followed during sign reversal of surface charge resulting from specific adsorption of ions. The results support the view that the large electro-optic effects manifested in the kilohertz and the hertz frequency regions are both related to parameters of the diffuse part of double electric layer: the kilohertz effect-to particle surface conductivity, and the negative hertz effect-to the value and profile of electrokinetic potential. The form of the frequency curves follows the changes in the ratio of those effects, hence of diffuse layer parameters. © 1991.