Micellar Kinetics of a Fluorosurfactant through Stopped-Flow NMR

Autor:	Peter Stilbs, István Furó, Pavel V. Yushmanov
Rok vydání:	2006
Předmět:	Aqueous solution Small-angle X-ray scattering Chemistry Chemical shift Relaxation (NMR) Kinetics Analytical chemistry Surfaces and Interfaces Fluorine-19 NMR Condensed Matter Physics Dilution Electrochemistry General Materials Science Dissolution Spectroscopy
Zdroj:	Langmuir. 22:2002-2004
ISSN:	1520-5827 0743-7463
DOI:	10.1021/la0529660
Popis:	19F NMR chemical shifts and transverse relaxation times T2 were measured as a function of time after quick stopped-flow dilution of aqueous solutions of sodium perfluorooctanoate (NaPFO) with water. Different initial concentrations of micellar solution and different proportions of mixing were tested. Previous stopped-flow studies by time-resolved small-angle X-ray scattering (TR-SAXS) detection indicated a slow (approximately 10 s) micellar relaxation kinetics in NaPFO solutions. In contrast, no evidence of any comparable slow (100 ms) relaxation process was found in our NMR studies. Possible artifacts of stopped-flow experiments are discussed as well as differences between NMR and SAXS detection methods. Upper bounds on the relative weight of a slow relaxation process are given within existing kinetic theories of micellar dissolution.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::90dde3230bb02cc77c6b2a1c0ff630cd https://doi.org/10.1021/la0529660 Zobrazit plný text záznamu