A very versatile model for the description of the viscosity of binary mixtures was developed. It is based on three premises: (i) the dissipation of energy takes place at the molecular surfaces, (ii) the friction between solvent and solute varies in the case of linear macromolecules with composition due to a change in the flow mechanism (drainage of coils), and (iii) the specific coil volume generally also depends on polymer concentration. The resulting simple expression contains four system-specific parameters: a geometric factor g, which accounts for the differences of the surface to volume ratios of the components; a viscometric interaction parameter a, which measures the friction between solute and solvent in the case of fully draining polymer coils, [h], the specific hydrodynamic volume of the polymer at infinite dilution (intrinsic viscosity), and [h]Q, the specific hydrodynamic volume under theta conditions. The suitability of this model has been demonstrated by means of extensive experimental data reported in the literature.



For more information, please see the following publications: 220, 211, 207, 197, 196, 150, 148, 116, 107, 60, 58, 42