High-pressure nuclear magnetic resonance relaxation study of supercritical dense fluids

The dynamic structure of simple polyatomic molecular fluids such as CF4, SF6, CFCl3, C4 F8, FC6D5, has been studied by nuclear magnetic resonance relaxation techniques. The effects of temperature and pressure on the transport and relaxation behavior of fluids in the supercritical dense fluid region have been investigated. These systematic studies led to the main conclusions of some of the general character: (1) Validity of the rough hard sphere model of liquids to describe transport and relaxation behavior of simple dense fluids; (2) Angular relaxation in fluids can be approximated as occurring through a sequence of uncorrelated binary collisions; (3) Importance of many-body correlation effects on self-diffusion which depends on transfer of linear momentum; (4) The results provided experimental verification of the molecular dynamics calculations for hard sphere systems; and (5) Applicability of the rough hard sphere model of liquids to describe relaxation and transport processes in binary mixtures.