The structure of water in aqueous solutions of polyoxyethylene monionic amphiphiles C10E5, where E5 denotes H2q(OCH2CH2)5OH, is studied by Raman scattering along an isothermal-path crossing the isotropic one-phase region from 0 to 1 amphiphile volume fraction phi. The isotropic OH stretching-vibration spectrum points out a water behavior that depends on the amphiphile concentration. The data analysis is performed using the bond-percolation model developed for water. The interpretation of scattering data leads to the following structural picture for the water in the systems: for phi lower than 0.75, water is partially bound to the oxyethylene groups of the amphiphile; above phi = 0.75 all water present in the system is bound. Analogously to the behavior of water in confined geometries, the structure of bound water presents a local fourfold-coordinated environment.
Raman scattering and water structure in non-ionic amphiphile solution / N. Micali, C. Vasi, F. Mallamace, M. Corti, V. Degiorgio. - In: PHYSICAL REVIEW E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS. - ISSN 1539-3755. - 48:5(1993), pp. 3661-3666.
Raman scattering and water structure in non-ionic amphiphile solution
M. CortiPenultimo
;
1993
Abstract
The structure of water in aqueous solutions of polyoxyethylene monionic amphiphiles C10E5, where E5 denotes H2q(OCH2CH2)5OH, is studied by Raman scattering along an isothermal-path crossing the isotropic one-phase region from 0 to 1 amphiphile volume fraction phi. The isotropic OH stretching-vibration spectrum points out a water behavior that depends on the amphiphile concentration. The data analysis is performed using the bond-percolation model developed for water. The interpretation of scattering data leads to the following structural picture for the water in the systems: for phi lower than 0.75, water is partially bound to the oxyethylene groups of the amphiphile; above phi = 0.75 all water present in the system is bound. Analogously to the behavior of water in confined geometries, the structure of bound water presents a local fourfold-coordinated environment.Pubblicazioni consigliate
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