Effect of Additives on the $ \hbox{I}_{2} + \hbox{I}^{-} \leftrightarrow \hbox{I}^{-}_{3} $ Reaction in Micellar Solutions of Sodium Dodecylsulfate: Partitioning and Solubilization Site of Iodine.
The partition constants (K(p)) of iodine between sodium dodecylsulfate micelles and the external media have been measured in the presence of water-soluble (sodium sulfate) and micelle-soluble (n-hexane and n-hexanol) additives. A spectrophotometric method based in the analysis of the alterations provoked by the presence of the surfactant plus the additives upon the reversible reaction taking place between iodine and iodide to give tri-iodide ions was employed (Abuin, E., and Lissi, E., J. Chem. Ed. 69, 340 (1992)). The effect of the additives upon the n-octanol/water partitioning (K(o/w)) of iodine was also determined. The results obtained for K(p) and its relationship with the K(o/w) values are indicative of a preferential localization of iodine at the surface of the micelles.
Abuin
E
Departamento de Ciencias Químicas, Facultad de Quídmica y Biología, Universidad de Santiago de Chile, Casilla 307, Correo, 2, Chile
Lissi
E
Velazquez
J