Spacer effects in dimeric cationic surfactants

A series of dimeric cationic surfactants (gemini surfactants), which have spacer groups of varying length and flexibility, was synthesized. The series is derived from the parent compounds dodecyltrimethylammonium chloride or benzyldodecyldimethylammonium chloride. Characteristic surfactant properties of the dimeric ammonium compounds such as surface activity, micellization, viscosity effects, foaming, and solubilization, were studied with respect to the influence of the spacer group on the surfactant. For all properties, the influence of the length of the spacer group was predominant though the chemical nature of the spacer cannot be neglected.