헤드그룹이 두 개인 음이온성 계면활성제의 미셀특성

Micellar Properties of Two-Headed Anionic Surfactants

Density, viscosity, conductance, dye solubility and carbon-13 nmr studies were performed in aqueous solution of three disodium 4-n-alkyl-3-sulfonatosuccinate anionic surfactant at 20℃. The cmc values were 0.14 mol/l for the disodium-4-n-octyl-3-sulfonatosuccinate(R₈S), 0.041mol/l for the disodium-4-n-decyl-3-sulfonatosuccinate(R₁₀S), and 0.018mol/l for the disodium-n-dodecyl-3-sulfonatosuccinate 〈R₁₂S). The aggregation numbers determined viscometrically and conductimetrically were 28 for R₈S, 48 for R₁₀S, and 67 for R₁₂S. The volume changes upon micellization were 8.9㎤/mol for R₈S, 9.5㎤/mol for R₁₀S, and 10.1㎤/mol for R₁₂S. Binding constants for the dye pada to the micelles and the fractions of unbound counter-ion were also obtained. The two polar heads with their carbon linkage were likely in an aqueous environment in the R₈S micelles with the micelles themselves being spherical.