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

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 (C₁₂ H ₂₆) at 0.5:0.5 mass fraction symmetric points, and for 0.9:0.1 mass fraction in IBB- C₁₂ H ₂₆. From the Stokes–Einstein equation and our experimental results, the limiting diffusion coefficients, D ⁰, and the equivalent solvated radii, R _s, have been estimated at infinitesimal concentration of these species (TNH, IBB and C₁₂ H ₂₆). 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: 0.33C₁₂ H ₂₆) and at 298.15 K.