Self-diffusion coefficients D for CH4, C2H6, and C3H8 have been measured at pressures up to 200 MPa and 450 K by the spin echo technique with pulsed field gradients. The experimental results for propane agree with data obtained by recent M. D. simulations with a three-site Lennard-Jones-skeleton model. In the p,T range studied, the experimental self-diffusion coefficients can be described quantitatively by the interacting sphere model and the rough hard sphere model. This implies, that even a single Lennard-Jones potential and diameter can represent the dynamic data for propane quantitatively.

Molar volumes of 1-, 2-, and 3-pentanol have been determined using a piston-cylinder apparatus. All isotherms are well described by the modified Tait equation (V0 -V)/V0 = A ln{(B + p)KB + p0)}, with a temperature-independent parameter A, while B proved to increase monotonically with falling temperature. The quality of the fits suggests that the results can be extrapolated reliably by the Tait equation to pressures and temperatures beyond the range covered by our experiments .

Densities for octamethylcyclotetrasiloxane + methane and 2,2-dimethylpropane + methane have been determined in the one-phase region at temperatures between 294 and 433 K for a maximum pressure of 200 MPa in a piston cylinder apparatus. Polynomials capable of describing the density as a function of P, T, and composition have been derived.

Diffusion / High Pressure / Isotope Effects / Liquids / Spectroscopy, Nuclear Magnetic ResonanceThe p , T-dependence of the self diffusion coefficients D for ethanol-OD, 1-and 2-propanol-OH and -OD have been studied in a wide temperature range at pressures up to 200MPa. The experiments were performed in strengthened high pressure glass cells by the pulsed field gradient NMR-technique. The isobaric temperature dependence of D is given by the VTF-equation. The isotherms can be fitted to the rough hard sphere model with an A-parameter that decreases strongly with falling temperature.

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