Transport and optical behavior of binary mixtures of isobutanol with aliphatic and aromatic hydrocarbons

The deviation in viscosity (Δη), excess Gibbs free energy of activation of viscous flow (ΔG∗E), and deviation in refractive index (ΔnD) were evaluated from the experimental viscosity (η) and refractive index (nD) data for binary mixtures of iso-butanol (1) with hydrocarbons such as n-hexane, cyclohexane, benzene, ethylbenzene and cumene (2) mixtures at T = 298.15 K and 308.15 K and at 0.1 MPa pressure. The behavior of the mixtures was interpreted in terms of dispersive and dipole–induced dipole interactions, along with structural effects arising from differences in molecular size and shape. The Δη values were satisfactorily correlated using an ab-initio approach. Negative values of Δη, ΔG∗E and ΔnD were obtained for all investigated binary mixtures. Furthermore, the numeric values of η and ηD were analyzed using various empirical correlations and mixing rules.