Synthesis, Characterization and Surface Properties of Series Sulfobetaine Surfactants

Abstract

Abstract A series of surface active sulfo‐propane betaines and sulfo‐butane betaines were synthesized with high yields by the reaction of an appropriate N , N ‐dimethyl alkylamine with an excess of 1,3‐propane sultone and 1,4‐butane sultone. The structures were characterized by 1 H‐NMR spectroscopy and elemental analysis. The micellar properties of these compounds were determined by surface tension methods. Surface tension measurements also provide information about the dependence of the surface tension at the CMC (γ cmc ), pC 20 (negative logarithm of the surfactant molar concentration C 20 required to reduce the surface tension by 20 mN/m), the surface excess (Γ max ) at air/solution interface, the minimum area per surfactant molecule at the air solution interface ( A ).