Study of the reaction between methyl 4-nitrobenzenesulfonate and bromide ions in mixed single-chain-gemini micellar solutions: Kinetic evidence for morphological transitions

Abstract

The reaction between methyl 4-nitrobenzenesulfonate and bromide ions has been studied in mixed single-chain-gemini micellar solutions of n-dodecyltrimethylammonium bromide, DTAB, and dodecyl tricosaoxyethylene glycol ether, Brij 35, with alkanediyl- α- ω-bis(dodecyldimethylammonium) bromide, 12- s-12,2Br − ( s = 3 , 4 , 5 ). Kinetic micellar effects show that an increase in the solution mole fraction of the single-chain surfactant, X single - chain , results in a diminution of the mixed micelles tendency to form spherocylindrical aggregates upon increasing surfactant concentration. The dependence of the surfactant concentration at which the sphere-to-rod transition occurs, C ∗ , on X single - chain showed through kinetic data was in agreement with results obtained by means of fluorescence measurements.