Influence of Chain Length of Alcohols on Stokes’ Shift Dynamics in Catanionic Vesicles
| Autor: | Biswajit Guchhait, Ranjit Biswas, Namrata Sarma, Harun Al Rasid Gazi, Jayanta M. Borah, Sekh Mahiuddin |
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| Rok vydání: | 2011 |
| Předmět: |
Aqueous solution
Chemistry Vesicle Cationic polymerization Alcohol Fluorescence spectroscopy Surfaces Coatings and Films chemistry.chemical_compound Crystallography Dynamic light scattering Benzyl alcohol Materials Chemistry Organic chemistry Physical and Theoretical Chemistry Sodium dodecyl sulfate |
| Zdroj: | The Journal of Physical Chemistry B. 115:9040-9049 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/jp201402h |
| Popis: | In this paper, we explore the effects of the chain length of simple monohydroxy alcohol (C(n)OH, 2 ≤ n ≤ 8) and benzyl alcohol (C(6)H(5)CH(2)OH) upon the fluorescence dynamics of a dipolar solute probe, coumarin 153 (C153), in vesicles formed in aqueous solutions of two oppositely charged (cationic and anionic) surfactants in the presence of 0.05 mol kg(-1) alcohol. The catanionic vesicles are composed of 70 mol % sodium dodecyl sulfate (SDS) and 30 mol % cetyltrimethylammonium bromide (CTAB). The presence of alcohols of different chain length improves the stability of the catanionic vesicles. Dynamic light scattering (DLS) experiments suggest a gentle increase in the hydrodynamic diameter of the catanionic vesicle with alcohol chain length up to n=4 and then an abrupt increase for the rest of the alcohols considered. The polarity and dynamics of the catanionic vesicles, probed by the steady-state and time-resolved fluorescence spectroscopy, indicate a signature of confined water. Quantities measured from fluorescence experiments of these vesicles also show a mild variation for alcohols of chain length n ≤ 4, followed by a sudden variation for alcohols with n4. Interestingly, pentanol and benzyl alcohol in catanionic vesicles showed roughly similar effects due to their equivalent chain length. All of these data are remarkably correlated with the recently observed depression of the solubility temperature of catanionics with alcohol chain length (Langmuir2009, 25, 12516-12521). |
| Databáze: | OpenAIRE |
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