Applications of Hyperpolarized Xenon to Diffusion in Vycor Porous Glass

Abstract

Applications of hyperpolarized xenon to the measurement of diffusion in porous materials were tested on porous Vycor glass. Ingression of hyperpolarized xenon into Vycor was followed both by measuring the changes in intensity of adsorbed xenon and by measuring the distribution in a selected slice of Vycor by NMR imaging. The resulting diffusion coefficients, 2.4 × 10-8 and 2.2 × 10-8 m2/s, respectively, compared well with each other, as well as with results obtained from pulsed field gradient measurements with thermally polarized xenon, 1.9 × 10-8 m2/s. Temperature-dependent measurements were used to derive an activation energy for diffusion of 4.1 kJ/mol. The experiments with hyperpolarized xenon gave large savings in experimental time.