New cationic surfactants with sulfonium headgroups

The synthesis of a new class of cationic surfactants with sulfonium headgro ups is presented. The use of common and easily accessible reactants allows a broad variation of the molecular surfactant structures, i.e., the synthes is of not only linear homologues but also of bola- or star-shaped surfactan ts. Surface tension measurements were used to determine the critical micell e concentration (cmc) and the surface excess concentration Gamma(infinity). The lyotropic phase behavior was investigated by polarized light optical m icroscopy. The influence of the hydrophobic chain length, the molecular str ucture of the headgroup, and the counterion on the surfactant properties is discussed.