Infinite dilution diffusion coefficients of aromatic compounds (benzene, toluene, chlorobenzene, ethylbenzene, p-chlorotoluene, naphthalene, pyrene, and perylene) in mixtures of hexane + heptane and of benzene in polar mixtures (hexane + ethanol and acetone + ethanol) were measured at 298.15 K by the Taylor dispersion technique. Experimental data were correlated by means of literature models depending in most cases on the diffusion coefficient of the solute at infinite dilution in the pure solvent. It is shown that the use of experimental values for should always be preferred to the Wilke−Chang predictions, especially in the case of nonideal mixed solvents. All models provide equivalent predictions except the Maxwell−Stefan and Dullien−Asfour equations, which lead to less stable results.

The Taylor dispersion technique was used to measure the diffusion coefficients of benzene, chlorobenzene, ethylbenzene, toluene, p-chlorotoluene, naphthalene, pyrene, and perylene at infinite dilution in mixtures of hexane + octane, hexane + decane, heptane + octane, heptane + decane, octane + decane, cyclohexane + hexane, cyclohexane + heptane, cyclohexane + octane, and cyclohexane + decane at 298.15 K. Experimental data were correlated satisfactorily by means of the Leffler-Cullinan equation using the measured values of solutes in the pure solvents and a group contribution method for estimating the viscosity of the solvent mixtures.

Diffusion coefficients of aromatic compounds at infinite dilution in binary mixtures have been measured at 298.15 K with respect to composition using the Taylor dispersion technique. The binary mixtures considered in this work were from alcohols (methanol, ethanol) and acetone with hexane, heptane, cyclohexane, carbon tetrachloride, and chloroform; the aromatic compounds were benzene, benzaldehyde, acetophenone, and phenol. The purpose of this work was to study the influence of the polarity of the binary mixtures on diffusion coefficients. The data were correlated by the Leffler−Cullinan equation, using the measured values of diffusion coefficients in pure solvents and estimating the viscosity of the binary mixtures with group contribution methods. Special attention was paid to the capability of models to take into account the polarity of the mixtures; for this purpose, in addition to the Grunberg−Nissan model, the UNIFAC-VISCO group contribution method was also considered.

In this study, infinite dilution diffusion coefficients of aromatic compounds in ternary mixtures were measured at 298.15 K using the Taylor dispersion technique. The experimental data of benzene in mixtures of hexane + heptane + cyclohexane, hexane + decane + cyclohexane, and methanol + ethanol + acetone and benzaldehyde in methanol + ethanol + water systems are reported. Modeling of experimental data was performed with literature models commonly considered for binary systems. Special attention was paid to their extension to ternaries using mixture viscosity correlations.