SELF-DIFFUSION IN COMPRESSED DIMETHYLETHER - THE INFLUENCE OF DIPOLE-DIPOLE INTERACTION AND HYDROGEN-BONDING UPON TRANSLATIONAL DIFFUSIVITYIN SIMPLE FLUIDS
A. Heinrichschramm et al., SELF-DIFFUSION IN COMPRESSED DIMETHYLETHER - THE INFLUENCE OF DIPOLE-DIPOLE INTERACTION AND HYDROGEN-BONDING UPON TRANSLATIONAL DIFFUSIVITYIN SIMPLE FLUIDS, Zeitschrift fur Naturforschung. A, A journal of physical sciences, 50(2-3), 1995, pp. 145-148
Self-diffusion coefficients of dimethylether have been measured as a f
unction of temperature (185-458 k) and pressure (up to 200 MPa) by pul
se-gradient field spin-echo NMR. Calculated activation volumes (Delta
V-not equal ) fall from 15 (10(-6) m(3)/mole) at the highest temperatu
re to 7 (10(-6) m(3)/mole) at the lowest. This trend is in keeping wit
h values for other non-associating liquids. Comparision with self diff
usion data for propane and ethanol reveals that the translational diff
usivity in dimethylether is influenced by the substance's modest dipol
e moment (1.3 Debye). The effect is small but measurable and becomes m
ore pronounced at lower temperatures.