ADDITIONAL SURFACE CONDUCTANCE OF THE THIN POROUS SURFACE-LAYER OF A COLLOIDAL PARTICLE

Additional surface conductance is the excess of total surface conducta nce over the conductivity of a diffuse electrical layer. The theoretic al calculation of this value is based on a concept of the porous surfa ce layer of a colloidal particle. The charge of the porous layer is de scribed by the Stern-Langmuir isotherm. Specific calculations have bee n performed for the special case of a thin porous layer when the depen dence of the potential on the layer thickness can be neglected. When t he layer is strongly charged, the additional surface conductance is lo w compared to the surface conductance of a diffuse layer, but when the layer charge is small, the additional surface conductance predominate s. The effect of low-frequency dispersion of the dielectric constant m ust be used for the measurements of the low values of surface conducta nce.