Diffusion Coefficients of Fluorinated Surfactants in Water: Experimental Results and Prediction by Computer Simulation
Pereira, L. A. M.[Luis A. M.], Martins, L. F. G.[Luis F. G.], Ascenso, J. R.[Jose R.], Morgado, P.[Pedro], Ramalho, J. P. P.[Joao P. Prates], Filipe, E. J. M.[Eduardo J. M.]
Intradiffusion coefficients of 2,2,2-trifluoroethanol in water have been measured by the pulsed field gradient (PFG)-NMR spin echo technique as a function of temperature and composition on the dilute alcohol region. The measurements extend the range of compositions already studied in the literature and, for the first time, include the study of the temperature dependence. At the same time, intradiffusion coefficients of 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoropropan-1-ol, and 2,2,3,3,4,4,4-heptafluorobutan-1-ol in water were obtained by computer simulation (molecular dynamics) as a function of composition and temperature. The intradiffusion coefficients of 2,2,2-trifluoroethanol in water obtained by simulation agree with the experimental results, while those of 2,2,3,3,3-pentafluoropropan-1-ol and 2,2,3,3,4,4,4-heptafluorobutan-1-ol are the first estimation of this property for those systems. The molecular dynamics simulations were also used to calculate the intradiffusion coefficients of perfluorooctanesulfonic acid and perfluorooctanoic acid in water at infinite dilution as a function of temperature, which are very difficult to obtain experimentally because of the very low solubility of these substances. From the dependence of the intradiffusion coefficients on temperature, diffusion activation energies were estimated for all the solutes in water.
Compounds
#
Formula
Name
1
C2H3F3O
2,2,2-trifluoroethanol
2
H2O
water
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.