EFFECT OF ADDITIVES ON THE I-2-[--]I-3(-) REACTION IN MICELLAR SOLUTIONS OF SODIUM DODECYL-SULFATE - PARTITIONING AND SOLUBILIZATION SITE OF IODINE(I)

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-hex anol) additives. A spectrophotometric method based in the analysis of the alterations provoked by the presence of the surfactant plus the ad ditives upon the reversible reaction taking place between iodine and i odide 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-oc tanol/water partitioning (K-o/w) of iodine was also determined. The re sults 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. (C) 1996 Academic Press, Inc.