ABSTRACT
In the Introduction, differences between self-diffusion coefficient andmutual diffusion coefficient are described andmethods to measure the coefficients are briefly reviewed. The selfdiffusion coefficient of counterions reflects the degree of counterion binding to micelles as well as the micellar size, shape, and morphology. Some examples are shown in Section II. From the self-diffusion coefficient of each surfactant in mixed surfactant solution, the fraction of each surfactant in the micelle, and then the composition of mixed micelles can be obtained, with some
examples shown in Section III. Section IV describes the selfdiffusion coefficient of mixed micelles, which reflects the size and charge of micelles and ionic strength of the medium. In Section V, the mutual diffusion coefficients of mixed surfactants are described. In the case of zwitterionic and long-chain ionic mixed surfactants, where the concentration of monomeric surfactant ion is extremely low, the mutual diffusion coefficient behaves like that of a spherical polyion. In the case of mixed surfactants, however, cross-term diffusion coefficients can be large.
