The density dependence of the self-diffusion coefficient of chlorotrifluoromethane near the critical temperature

In this paper are reported NMR spin-echo measurements of the self-diffusion coefficient of chlorotrifluoromethane at 30°, 50° and 75°C over the density range 3 to 15 mol dm-3. No evidence was found for the type of critical region anomaly recently reported by Duffield and Harris for carbon dioxide. The high density data are correlated with molecular dynamics computer simulated data for hard spheres. The translational-rotational coupling factor for Chandler's rough hard sphere model is found to be 0.90±0.02. For the viscosity the coupling factor is 0.77±0.02. These values are found to be consistent with limits set by classical hydrodynamic theory.