A simplified method for predicting the dynamic surface tension of concentrated surfactant solutions

摘要

A simplified method for predicting the dynamic surface tension of concentrated surfactant solution is proposed. It is implemented using the framework of the Henry's Law analytical solution to the Ward and Tordai equation for diffusion-controlled adsorption, with the necessary parameters being deduced from the measured equilibrium surface tension equation and a value for the surfactant monomer diffusivity. The method is tested by calculating the dynamic surface tension relaxations of aqueous C_10E_6 and C_10E_8 solutions over concentration ranges from well below to well above their critical micelle concentrations (cmc). Results are compared with measured over concentration ranges from well below to well above their critical micelle concentrations (cmc). Results are compared with measured relaxations over 0.005-50 s, and semiquantiative agreement is found, with the best rsults obtained for concentrations near the cmc. The predictive method may prove useful in such applications as the screeing to candidate surfactants for ink used in injket printing.