Gravitational Drainage of Anionic and Nonionic Surfactant Mixtures for Foamability Enhancement

Two surfactant mixture solutions were used to study gravitational drainage from thin vertical planar films and in a settler column. The surfactant mixtures contained anionic surfactant Sodium Dodecyl Sulfate (SDS) and nonionic superspreader trisiloxane SILWET L-77 at different mixing ratios. We found the relation between the lifetime of planar vertical film and foamability of the surfactant solution. Namely, solutions with longer lifetimes in planar film drainage reveal a higher foamability. Also, the foamability of the mixed surfactant systems was found to be greater than the foamability of each of the individual components.