title: Slow water diffusion in micellar solutions.
abstract: Slowly diffusing water molecules were found by quasi-elastic neutron scattering (QENS) in a sodium dodecyl sulfate (SDS) micellar solution, and both their diffusion coefficient (4.33 x 10(-6) cm2 x s(-1)) and mole fraction (0.057) were determined. After successfully checking the mean slowing down of solvent molecules by the gradient compensated stimulated spin-echo (GCSTE) pulse sequence NMR method, a similar effect was observed with this technique in the solvent phase of dodecyl trimethylammonium bromide (DTAB) and differing chain length (X = 12, 20, 30, and 40) ethoxylated nonyl phenol (9NX) micellar systems. Following the literature, the experimental results are qualitatively explained by assuming that, apart from ionic hydration, H-bonds may form between the solvent molecules and the O or N atoms present in the hydrophilic (head)groups of the micelle-forming monomers.
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Vass
authors.forename: Hans
authors.initials: H
authors.lastname: Grimm
authors.forename: István
authors.initials: I
authors.lastname: Bányai
authors.forename: Gerhard
authors.initials: G
authors.lastname: Meier
authors.forename: Tíbor
authors.initials: T
authors.lastname: Gilányi