Viscosity and Density of Carbon Dioxide + 2,6,10,15,19,23-Hexamethyltetracosane (Squalane)

The viscosity and density of mixtures of carbon dioxide and 2,6,10,15,19,23-hexamethyltetracosane (squalane) are reported. The measurements were carried out using a vibrating wire instrument over a range of temperatures from (303.15 to 448.15) K and at pressures ranging from approximately the minimum miscibility pressure at a given composition to 170 MPa. Pure squalane and three different mixtures, with mole fractions of CO 2 of 0.423, 0.604, and 0.788, were investigated. The estimated expanded relative uncertainties of the measurements were ± 2 % for viscosity and ± 0.2 % for density with a coverage factor of 2. The data for each composition were correlated by simple expressions with an absolute average relative deviation less than 2 % for viscosity and less than 0.2 % for density. The results show that the addition of CO 2 to squalane at a given pressure and temperature reduces greatly the viscosity and increases slightly the density. A hard-sphere model, adjusted to fit the viscosity data of the pure substances but containing no adjustable binary parameters, was tested against the experimental data. Relative deviations bounded by approximately ± 60 % were found.