Temperature and gas pressure induced microstructural changes in AOT water-in-oil microemulsions: characterization through electron paramagnetic resonance spectroscopy
| Autor: | Gary L. McPherson, Yan Waguespack, Vijay T. John, Nagesh S. Kommareddi |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
chemistry.chemical_classification
Cloud point Aqueous solution Chromatography General Engineering law.invention Physics::Fluid Dynamics Condensed Matter::Soft Condensed Matter Solvent Hydrocarbon chemistry Chemical physics law Microemulsion Physical and Theoretical Chemistry Electron paramagnetic resonance Spin label Dissolution |
| Zdroj: | The Journal of Physical Chemistry. 97:5752-5761 |
| ISSN: | 1541-5740 0022-3654 |
| DOI: | 10.1021/j100123a048 |
| Popis: | EPR spectra of a variety of nitroxide spin labels have been used to characterize microstructural changes in AOT water-in-oil microemulsions at conditions approaching critical phase transitions. Of particular interest is a pressure-induced cloud point, where the dissolution of a light hydrocarbon gas into the liquid solvent (isoctane) reduce the solvent density and leads to micellar instability at a critical density. The pressure approach to a cloud point is compared to the temperature approach. A variety of spin label probes are used to report changes in the aqueous core, the interfacial layer, the micellar tail region, and the intermicellar bulk isooctane region. Both temperature and gas pressure increased result in a decrease of the rigidity (ordering) in the immediate vicinity of the surfactant layer in the interfacial region |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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