Abstract: The diffusion coefficients of the SDS(Sodium dodecyl sulfate) molecules in lyotropic liquid crystal of SDS/n-C5H11OH/H2O system have been determined by the method of platinum microelectrode voltammetry.The results show that the diffusion coefficients of SDS molecules in lyotropic liquid crystal increase with water content at constant mass ratio of SDS/n-C5H11OH and also with n-pentanol content at constant mass ratio of SDS/H2O, but decrease with SDS content at constant mass ratio of H2O/n-C5H11OH.The diffusion coefficient of the SDS molecule in hexagonal liquid crystal is nearly one order of magnitude less than that of the SDS molecule in lamellar liquid crystal, but is about three to five orders less than that of the W/O and the O/W droplets.

Key words: SDS, Microelectrode, Micelle, Lyotropic liquid crystal, Diffusion coefficient