Viscosity of aqueous CO₂ solutions measured by dynamic light scattering

The viscosity of water containing dissolved CO₂ at pressures up to 5 MPa was measured by a new method based on dynamic light scattering. The accuracy of this method was checked by measuring the temperature dependence of the viscosity of pure water at pressures up to 5 MPa and comparing the results to values in the literature that were determined by other methods. The discrepancy of the measured viscosity of water from the literature was ±6%, which roughly equals the composite uncertainty of this method. The effect of dissolved CO₂ on the viscosity was determined as functions of time, temperature, and pressure. The results indicated that the viscosity of the solution increased with increasing CO₂ concentration. High viscosities were observed under conditions in which CO₂ hydrates can form.