Density expansion of the viscosity of carbon dioxide near the critical temperature

We present a detailed experimental study of the viscosity of carbon dioxide as a function of density at a temperature near the critical temperature. Kinetic theory predicts the presence of a logarithmic term in the density expansion for the viscosity of gases. While it is difficult to prove the existence of such a term experimentally, the data are consistent with a possible logarithmic contribution of an order of magnitude estimated theoretically by Kan.