PFG-NMR and MD Simulation Study of Self-Diffusion Coefficients of Binary and Ternary Mixtures Containing Cyclohexane, Ethanol, Acetone, and Toluene

Recently, Guevara-Carrion et al. published a comprehensive molecular dynamics (MD) study on the thermodynamic properties of binary mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride which also includes results on self-diffusion coefficients. However, for the mixtures acetone/cyclohexane, acetone/ethanol, acetone/toluene, cyclohexane/ethanol, and toluene/ethanol, no experimental data on self-diffusion coefficients were available for comparison. Therefore, in the present work, self-diffusion coefficients in these mixtures were measured by 1H NMR spectroscopy using pulsed field gradients (PFGs) at 298.15 K and ambient pressure. The experimental data were compared to the simulations of Guevara-Carrion et al. Good agreement was observed for all mixtures that do not contain ethanol, whereas, for ethanol-containing mixtures, the deviations were larger. This finding is attributed to deficiencies of the molecular model in describing the hydrogen-bonding of ethanol. Furthermore, self-diffusion data for the ternary mixture acetone/toluene/cyclohexane were measured and compared to molecular simulation data from the present work. Good agreement was observed.