Order parameter profile of perfluorinated chains in a lamellar phase
2000 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 16, no 6, 2962-2967 p.Article in journal (Refereed) Published
Cesium perfluorooctanoate molecules are investigated by NMR spectroscopy in the lamellar phase of their aqueous solution. The particular NMR method, C-13-detected, F-19-decoupled separated-local-field (SLF) spectroscopy, provides the dipolar splitting of each C-13 spin to its F-19 neighbors. These dipolar splittings are interpreted in terms of the molecular C-F bond order parameters of each difluoromethylene and trifluoromethyl group. The obtained variation of this order parameter along the fluoroalkyl chain strengthens the conclusion from an earlier, model-dependent study (Fur6, I.; Sitnikov, R. Langmuir 1999, 15, 2669): perfluorinated surfactant chains are significantly more rigid than their hydrogenated counterparts.
Place, publisher, year, edition, pages
2000. Vol. 16, no 6, 2962-2967 p.
pentadecafluorooctanoate-water-system, nuclear magnetic-relaxation, h dipolar couplings, liquid-crystals, spin relaxation, nmr measurement, c-13, dynamics, resonance, anisotropy
IdentifiersURN: urn:nbn:se:kth:diva-19637ISI: 000085984500078OAI: oai:DiVA.org:kth-19637DiVA: diva2:338329
QC 201005252010-08-102010-08-10Bibliographically approved