Rheological properties of vacuum residue fractions in organic solvents

We report our rheological study on Ratawi vacuum residue fractions in various organic solvents. Both light and heavy ended fractions form colloidal particles in these solvents, and the mixtures exhibit Newtonian behaviour. The viscosity data was analysed using various available theories, to determine their colloidal structure and the degree of solvation. We also studied the viscosity response to temperature for the heavy ended fractions in toluene, where a glass-like phase boundary was observed at low temperature.