Syntheses of Tartaric Acid-Based Hybrid Gemini Surfactants Containing Fluorocarbon and Hydrocarbon Chains

Tartaric acid-based symmetric and hybrid gemini surfactants having dodecyloxy (C12H25O-) and tridecafluoro nonyloxy groups (C6F13(CH2)(3)O-) as hydrophobic groups were synthesized, and their surface properties were studied by surface tension (gamma)-concentration and surface pressure-area (pi-A) measurements. All geminis showed superior surfactant properties to 1 + 1 type surfactant. Especially, hybrid gemini showed high efficiency of lowering the surface tension comparable to that of bis(C6F13(CH2)(3)O) gemini. Further, hybrid gemini showed an unusual existence of two breakpoints at gamma = similar to 25 and 18 mN m(-1). In the pi-A measurements, regardless of symmetric or hybrid structures, geminis having fluoroalkyl group formed only liquid condensed monolayers while the bis(dodecyloxy) gemini formed solid monolayer. Molecular occupied areas of hybrid gemini were subequal to the mean of those of symmetric geminis.