Ultrasonic, volumetric and viscometric studies of molecular interactions in binary mixtures of dimethylsulphoxide with polar substituted cyclohexanes at 30°C

The densities, rho, ultrasonic speeds, u and viscosities, eta of binary mixtures of dimethylsulphoxide ( DMSO) with cyclohexanol, cyclohexanone and cyclohexylamine, with DMSO as a common component, over the whole composition range expressed by mole fraction of DMSO, including those of pure liquids have been measured at 30 degrees C. By using the experimental values of rho, u and eta, the deviations in isentropic compressibility, Delta k(s), excess intermolecular free length, L-f(E), excess molar volume, V-E, deviations in viscosity, Delta eta, excess free energy of activation of viscous flow, G(*E), partial molar compressibility and volume, (K) over bar (o)(phi,2) and (V) over bar (o)(phi,2) respectively of cyclohexanol/ cyclohexanone/cyclohexylamine in DMSO at infinite dilution have been calculated. The variations of these parameters with composition of the mixture suggest that the strength of interactions in these mixtures follow the order: cyclohexanol< cyclohexanone< cyclohexylamine. The isothermal compressibility, k(T) for these binary mixtures has been theoretically calculated by using the Flory's statistical theory and five hard sphere models and the results were compared with the experimental k(T) values. Further, the viscosities of these binary mixtures were theoretically predicted on the basis of various relations by using the experimental values of pure components and the results were compared with the experimental findings.