Influence of solubilised dodecane on the dynamic surface tension and dilational rheology of micellar Triton X-45 and SDS solutions

Abstract

Maximum bubble pressure tensiometry is used to measure the dynamic surface tensions of micellar solutions of TX45 and mixtures of SDS/TX45 at the solution/air interface. For measurements of the dilational visco-elasticity of the micellar solutions the buoyant bubble profile tensiometry with harmonic bubble surface area oscillations is applied. The influence of dodecane solubilised in TX45 and mixed SDS/TX45 micelles, respectively, on the dynamic surface tension and dilational characteristics of these micellar solutions is determined. It is shown that the solubilisation of dodecane by micelles leads to a slowdown in the dynamic surface tension change and an increase in the visco-elasticity of the micellar solutions. Theoretical models proposed earlier are used for the description of the influence of solubilised dodecane on the dynamic surface tension and visco-elasticity of micellar TX45 solutions. It is shown that the presence of solubilised dodecane leads to a decrease of the CMC value, and to a decrease of the micelles diffusion coefficient.