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

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

Abstract
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.