Kernmagnetische Messungen von Selbstdiffusions-Koeffizienten in Wasser und Benzol bis zum kritischen Punkt

Abstract

The most commonly used nuclear magnetic resonance spin-echo methods for determining selfdiffusion coefficients D are described; some experimental data are presented for protons in water and in benzene from room temperature up to the critical point. The results are interpreted in terms of the free-volume rate theory of MACEDO and LITOVITZ. The D-value of benzene may be described by a single activation energy. Water, however, shows such behavior only at high temperatures, thus demonstrating the strong influence of hydrogen bonding. The STOKES-EINSTEIN relation between diffusion coefficient and viscosity is well satisfied over that part of the temperature range where viscosity values are available.