Properties of charged non-aqueous colloids in a low conductivity regime

Abstract

Extensive investigation of the properties on non-aqueous charged colloids was undertaken utilizing quasi-elastic light scattering, optical and electrical transients and electrical platecuts. For the first time all basic physical properties of low conductivity colloids were measured. These include size, mobility and charge of colloidal particles, mobilities and concentration of counterions and excess ions, and also size and charge stability. It is shown that highly charged nonaqueous colloids are attainable in a low dielectric media despite of a low degree of dissociation of ionizable species. The importance of space charge conditions is identified and their universal scaling law illustrated for these low conductivity colloids. Ions of one polarity predominate in the double layer, and thus classical treatments of electrophoresis may not apply to these colloids.