Lateral electrical conductivity in aerosol-OT-water systems

Abstract

Studies of lateral electric conductivity have been performed in the lamellar liquid crystalline phase of the binary system sodium di-2-ethylhexylsulfosuccinate (Aerosol OT) and water over its whole concentration range of existence. Special care was taken to eliminate the influence of polarization effects and other artifacts. A pronounced maximum was observed in the conductivity at about 60% Aerosol OT. In addition, the temperature dependence was found to be different at low and high Aerosol OT content. The behavior of the conductivity is explained in terms of geometrical and electrostatic factors which influence the movement of charge carriers along thin water layers. The condition in the narrow water layers at low water contents of the Aerosol OT system are similar to those of ionic channels in nerve membranes. This similarity makes measurements on well-characterized lamellar lipid-water systems particularly worthwhile.