Self Diffusion in Carbon Dioxide Near the Critical Point

Measurements of the self diffusion coefficient, D , by the nuclear‐magnetic‐resonance field‐gradient method for carbon dioxide ( 13 CO 2 ) are reported for the coexisting liquid from the triple point to the critical point and for the fluid at the critical density from the critical temperature upwards. No anomaly in D is observed near the critical point and the behaviour is similar to that of other liquids. It seems likely that the previously reported anomalous behaviour (Duffield and Harris, 1976), in 14 CO 2 , measured by the capillary method, is erroneous.