REACTION-KINETICS IN MICROEMULSION MEDIUM .1. INVERSION OF CANE SUGAR IN QUATERNARY SYSTEM OF MICROEMULSION CONTAINING WATER TRITON X-100/1-BUTANOL (CHOLESTERYL BENZOATE + N-HEPTANE)

The H3O+ ion catalyzed inversion of cane sugar was studied in water/poly(oxyethylene) isooctylphe-nyl ether/1-butanol/(cholesteryl benzoate + n-heptane) microemulsion medium at a constant surfactant/ cosurfactant ratio and at different oil/water ratios. Increasing the O/W ratio increased the rate, 0.5% (w/v) dextran and 2% (w/v) brine moderately retarded it, whereas urea retarded it markedly. In water-dioxane medium, increasing the proportion of dioxane increased the rate of inversion. The results are analyzed in light of the polarity of the medium as well as the effective concentration of the catalyst (H3O+) in the microemulsion. The temperature effect on the rate of inversion revealed that with increased proportion of oil in microemulsion and dioxane in water the transition state complex ends up with a lower activation energy; the variation is systematic in the former but not in the latter. © 1990, American Chemical Society. All rights reserved.