THE DYNAMIC SURFACE-TENSION OF SDS-DODECANOL MIXTURES .2. MICELLAR SDS-DODECANOL MIXTURES

The effect of dodecanol is micellar SDS solutions on the dynamic surface tension is considered by taking into account a production term in the diffusion equation. This equation is integrated by assuming local equilibrium in the bulk between dodecanol as monomers and as stabilized in the micelles. The aspect of the dynamic surface tension behavior is consistent with a diffusion controlled adsorption process, with an apparent diffusion coefficient many times too high as compared with the real diffusion coefficient. An expression for this apparent diffusion coefficient as a function of the real diffusion coefficient and the distribution of dodecanol between the micellar phase and the monomers is given. The experimental results are in agreement with the theory and experimental data obtained by different methods are internally consistent.