TRANSLATIONAL MOLECULAR-MOTION OF A LIQUID IN DISPERSED MAGNESIUM-OXIDE

The method of impulsive NMR with an impulsive magnetic field gradient (IMFG) is used to study the translational mobility (self-diffusion - SD) of molecules of tridecane in dispersed magnesium oxides with specific surfaces S1 of 8.4 and 225 m2/g. Measurements are made of diffusional attenuation of the amplitude of the spin echo in relation to the square of the IMFG. The self-diffusion coefficients of the liquid are also measured. When the pores are partly filled, the diffusant may be in a ''gaseous'' state in which in molecules possess anomalously high translational mobility. It is shown that this state cannot be identified as a typical gas phase. The self-diffusion of the liquid in the porous medium is very sensitive to S1. An analysis of the mode of diffusional attenuation makes it possible to determine structural differences which exist in the given magnesium oxides.