Optimization of Taylor Dispersion Technique for Measurement of Mutual Diffusion in Benchmark Mixtures

Abstract

The Taylor dispersion technique has been used for measuring binary mutual diffusion coefficients for mixtures of 1,2,3,4-tetrahydronaphthalene (THN), isobutylbenzene (IBB) and dodecane (C12H26) at 0.5:0.5 mass fraction symmetric points, and for 0.9:0.1 mass fraction in IBB- C12H26. From the Stokes–Einstein equation and our experimental results, the limiting diffusion coefficients, D0, and the equivalent solvated radii, Rs, have been estimated at infinitesimal concentration of these species (TNH, IBB and C12H26). The measured diffusion coefficients are used to estimate activity coefficients of the components in the mixture, contributing to a better understanding of the structure of such systems and of their thermodynamic behaviour at different concentrations. We have also investigated the diffusion properties for a ternary system containing equal mass fractions of all the components (0.33THN: 0.33IBB: 0.33C12H26) and at 298.15 K.