Excess volumes and viscosities of mixtures of dimethylsulfoxide with normal alcohols at 40°C

Excess volumes and viscosities have been determined for DMSO + n-hexanol, + n-heptanol, + n-octanol, and + n-decanol at 40°C. The excess partial molar volumes V₁^E, changes in viscosities , the parameter d of the Grunberg and Nissan expression, and excess Gibbs free energies of activation of flow G_*^E have been calculated from the experimental data. All the excess volumes are positive over the whole composition range, with V^E increasing with the length of the alkanol chain. V^E results are discussed in terms of disruption of alkanol multimers, weakening of interactions between DMSO molecules, influence of interactions between components, and structural effects. The V^E data have also been analyzed using the Prigogine-Flory-Patterson expression which separates V^E into three contributions. Correlation is also observed between the sign of and V^E for all the mixtures studied.