Effect of changing hydrodynamic conditions on the rate of processes at liquid—liquid interfaces: metal ion extraction and water solubilization by reversed micelles
✍ Scribed by C.A. Savastano; E.S. Ortiz
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 940 KB
- Volume
- 46
- Category
- Article
- ISSN
- 0009-2509
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✦ Synopsis
Rates of water uptake by reversed micelles of a strong surface-active agent [dinonylnaphthalenesulphonic acid (HDNNS)] in n-hexane have been studied. Rates of the interfacial transfer of Ni(II) as DNNS complexes under varying hydrodynamic conditions in the phases were also investigated. The extraction took place under regimes shifting from mass transfer dominated to kinetically controlled by the interaction between reversed micelles and the adsorbed film at the interface Comparison of experimental results with predictions by a solution to the second Fick law confirmed the previous finding that interaction between micelles and the interface is the mechanism responsible both for metal ion extraction and water dispersion as a microemulsion within the organic solvent. Molecular diffusion of'metal-micelle complexes was simulated according to Higbie's penetration theory, and the renewal of fluid elements adjacent to the interface with Dankwerts' random frequencies. Using renewal frequencies estimated from water solubilization experiments, the effect of changing hydrodynamic conditions on metal ion transfer fluxes was reproduced.
From the data, a mlcelle-interface interaction rate constant was estimated m order-ofmagnitude agreement with literature values. The analysis successfully interprets the effect of varying hy&odynar& conditions on metal transfer fluxes.