Solute-Solvent Contact by Intermolecular Cross Relaxation: II. The Water-Micelle Interface and the Micellar Interior
2006 (Swedish)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 110, no 51, 25775-25781 p.Article in journal (Refereed) Published
The intermolecular dipole-dipole cross-relaxation is measured between F-19 nuclei of sodium perfluorooctanoate in micelles and H-1 nuclei of the water solvent. The cross-relaxation rates for fluorines in the different moieties along the surfactant vary strongly by the resonance frequency in the investigated range of 188-470 MHz. This frequency dependence indicates that the cross-relaxation between water and amphiphilic aggregates is not controlled solely by the fast local water dynamics but significantly contributed to by the long-range translational diffusion of water. The cross-relaxation rates, analyzed in the framework of a model (Nordstierna, L.; Yushmanov, P. V.; Furo, I. J. Chem. Phys. 2006, 125, 074704), provide information about the dynamic retardation of water molecules by the micellar headgroup region and the location of the various moieties along the hydrophobic tail with respect to the water-micelle interface. Both intermolecular cross-relaxation and aggregation-induced F-19 chemical shift changes indicate no direct water contact to fluorines except for those closest to the head group.
Place, publisher, year, edition, pages
2006. Vol. 110, no 51, 25775-25781 p.
nuclear-magnetic-resonance, overhauser effect measurements, molecular-dynamics simulation, ionic surfactant micelles, order-parameter profile, sodium dodecyl-sulfate, spin relaxation, magic-angle, translational diffusion, conformational-analysis
IdentifiersURN: urn:nbn:se:kth:diva-5690DOI: 10.1021/jp0647885ISI: 000242974300038ScopusID: 2-s2.0-33846400071OAI: oai:DiVA.org:kth-5690DiVA: diva2:10137
Uppdaterad från submitted till published: 20100914
QC 201009142006-05-102006-05-102012-03-22Bibliographically approved