Schrödle, Simon and Hefter, Glenn and Kunz, Werner and Buchner, Richard (2006) Effects of Nonionic Surfactant C12E5 on the Cooperative Dynamics of Water. Langmuir 22 (3), pp. 924-932.
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A dielectric relaxation study of binary mixtures of nonionic surfactant C12E5 + water has been made as a function of temperature in the isotropic micellar, lamellar, and hexagonal regions of the phase diagram. Two dielectric dispersion steps were found and could be assigned to the intermolecular cooperative dynamics of water at the micellar interface and in the bulk water domains. A quantitative analysis is given. The relaxation amplitudes were used to determine effective hydration numbers. The activation energies of water relaxation were calculated from the relaxation times. The data indicate weaker surfactant-water and water-water interactions near the micellar interface compared to those of bulk liquid water. Further analysis revealed the presence of water clusters large enough to show a cooperative relaxation mode even at high surfactant concentrations. However, the relaxation time of this mode is larger compared to that of pure water. This points out the importance of confinement effects on water dynamics.
|Date:||31 January 2006|
|Institutions:||Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie|
|Subjects:||500 Science > 540 Chemistry & allied sciences|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||30 Jun 2006|
|Last Modified:||20 Jul 2011 20:47|