Physicochemical properties, surface active species and formation of reverse micelles in the Cyanex 923-n-heptane/cerium(IV)-H2SO4 extraction system
✍ Scribed by Weiwei Wang; Xianglan Wang; Yanliang Wang; Deqian Li; Wuping Liao
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2008
- Tongue
- English
- Weight
- 139 KB
- Volume
- 83
- Category
- Article
- ISSN
- 0268-2575
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✦ Synopsis
Abstract
BACKGROUND: The Cyanex^®^ 923 (trialkylphosphine oxides, TRPO)‐n‐heptane/cerium(IV)‐H~2~SO~4~ extraction system has been investigated focusing on the physicochemical properties, surface active species and interfacial phenomena. The effects of H~2~SO~4~ and Ce(IV) extraction on them were considered.
RESULTS: Results showed that the density and refractive index reflect the mass transfer by H~2~SO~4~ and Ce(IV) extraction and the change of refractive index was more sensitive than density. The interfacial tension decreased on extraction of H~2~SO~4~ but increased on extraction of Ce(IV). The viscosity of the equilibrium organic phase increased abruptly when the extracted H~2~SO~4~ concentration in the organic phase reached certain high values. The formation of reversed micelles, with mean diameter of about 10 nm, at high H~2~SO~4~ concentrations in the organic phase, is suggested by various measurements such as viscosity, interfacial tension and dynamic light‐scattering (DLS).
CONCLUSION: It is suggested that TRPO‐H~2~SO~4~ complexes are more surface‐active than TRPO itself and tend to aggregate into reverse micelles by self‐assembling in the organic phase but the Ce(IV)‐TRPO complexes are neutral, less surface‐active than TRPO and not helpful for reverse micelle formation. Copyright © 2008 Society of Chemical Industry