Interaction between Anionic and Zwitterionic Surfactants: Sodium Dodecyl Sulfate and N‐alkyl‐N,N‐dimethylsulfobetain,N‐lauroylsarcosine

The interaction between anionic and zwitterionic surfactant has been investigated through the measurements of surface tension and pH. These systems are sodium dodecyl sulfate (SDS) and N‐alkyl‐N,N‐dimethylsulfobetain(SB) N‐lauroylsarcosine(NL). As the molar ratio of SDS to SB is 7:3, the cmc of these systems exhibits minimum and the surface activity is in‐depend on pH. As the molar ratio of NL to SDS is from 3:7 to 7:3, the synergistic effect of the systems exhibits significantly, the surface tension increases with decreasing of pH and deposits has formed.

Keywords:

• Synergistic effect
• surface tension
• deposits

Acknowledgments

Project supported by the National Natural Science Foundation of China (Grant 50373017), Young and Middle‐aged Scientist Foundation of Shandong Province (Grant 02BS051) and Shandong Provincial Education Department (Grant J02C06).