DYNAMIC PROPERTIES OF SOLUBLE MONOLAYER OF SODIUM DODECYL-SULFATE (SDS) ON AQUEOUS-SOLUTION

The relaxation phenomenon of the surface elasticity was investigated f or a soluble mono-molecular layer of sodium dodecyl sulfate (SDS) on a queous solution. Two kinds of experiments, induced surface wave measur ement and ripplon light scattering, were performed at frequencies of 1 kHz and 40 kHz, respectively. In the dilute region below the critical micellar concentration (CMC), the concentration dependence df the sur face elasticity obtained at 1 kHz is well explained by the theory of d iffusion-dominated relaxation, while the surface elasticity at 40 kHz was found to exceed the low-frequency value, which suggests another re laxation mechanism. The results obtained above the CMC were also prese nted.