Abstract
The dielectric constants and A.C. electrical conductivity of sodium alkyl sulfates in aqueous solutions were measured in the frequency range 30Hz to 1MHz. As the number of carbon atoms in the chain of the surfactant molecule was increased, the dielectric properties at lower frequencies were greatly affected by polarization on the surfaces of the electrode, the so-called space charge polarization. A.C. electrical conductivities were dependent on the concentration of sodium. alkyl sulfate at all frequencies. The activation energies of A.C. electrical conductivity increased with increasing number of carbon atoms in the surfactant molecule. The radius of a micelle with an electric double layer could be calculated through the measurements of the dielectric constant and the A.C. electrical conductivity. It is found that the radius of the micelle decrease with increasing number of carbon atoms in the chain of the surfactant molecule.
