Self-diffusivity measurements of dimethyl, diethyl, dipropyl, dibutyl, Bis(2-ethylhexyl) adipates from (293–339) K by a PGSE–NMR spin-echo technique

Abstract

The article reports self-diffusivity measurements of dimethyl (DMA), diethyl (DEA), dipropyl (DPA), dibutyl (DBA), and bis(2-ethylhexyl) (DEHA) adipates from (293–339) K by the PGSE–NMR technique. The expanded uncertainty of the results is estimated to better than ±2%. The results are interpreted in terms of the hydrodynamic and the van der Waals radii. The former are calculated a Stokes-Einstein-Sutherland-type equation, using recently published viscosity data. Furthermore, recently published density data for those adipates are used to calculate the hard sphere radii at contact in a cubic lattice, in order to compare the radii obtained from transport properties with those obtained from equilibrium data. In this temperature range the self-diffusivities of the liquid dialkyl adipates studied have an Arrhenius-like behavior.