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

The viscosity and density of mixtures of carbon dioxide and 2,6,10,15,19,2 3-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 CO2 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 CO2 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.