ISSN:
0392-6737
Keywords:
Disperse systems
;
PACS 78.30
;
Infrared and Raman spectra and scattering
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Summary The structure of water in bis(2-ethylhexyl)sodium sulfosuccinate (AOT) micelles has been studied as a function of the [H2O]/[AOT] ratio (W) by using the absorption IR due to O−H stretching modes in the 3800–3000 cm−1 range. Three systems have been studied: water/AOT/carbon tetrachloride, water/AOT/n-heptane and water/AOT iso-octane. Experimental spectra are presented and discussed for the O−H stretching region both of H2O and isotopically diluted HDO molecules in D2O. We have restricted ourselves to the region of small amounts of water (0〈W〈20) where the properties of the systems change strongly with the water content. The results show that IR spectra can be expressed as sum of contributions from interfacial and bulk-like water. The fraction of water in the two “regions” within the water pool was evaluated as a function ofW. From the data a continuous variation appears in the water properties inside micellar cores rather than a two-steps hydration mechanism. The solubilization of water is described in terms of hydration of the AOT head group and Na+ counterions. The maximum hydration number of AOT was found to be 3.5. The same behaviour has been observed in the three solvents studied.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02456791
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