J. Phys. II France
Volume 6, Numéro 5, May 1996
Page(s) 657 - 666
DOI: 10.1051/jp2:1996204
J. Phys. II France 6 (1996) 657-666

Temperature dependence of Water Self-Diffusion in the Gel phase of a Potassium Palmitate System

L. Coppola, R. Muzzalupo and G.A. Ranieri

Department of Chemistry, University of Calabria, 87030 Arcavacata di Rende, Cosenza, Italy

(Received 14 September 1995, revised 13 November 1995, accepted 8 February 1996)

The temperature dependence of water self-diffusion in the gel and liquid crystalline phases of the potassium palmitate/water system was examined using pulsed field gradient spin-echo (PGSE) low resolution NMR experiments. The temperature dependence of the water self-diffusion in lamellar and hexagonal phases was characterised by trends parallel to pure water. The average "two-site" self- diffusion model was used to analyse the composition dependence of the self-diffusion coefficients. Temperature dependence of water self-diffusion in the gel phase presented different and interesting behaviour. The slopes of the Arrhenius self-diffusion were strongly composition dependent. The results were interpreted as a dependence on T of the bound water fraction, while the self-diffusion obstruction factor was considered constant.

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