Measurements and correlation of diffusion coefficients of ibuprofen in both liquid and supercritical fluids

Abstract

The diffusion coefficients of ibuprofen in both liquid and supercritical fluids are presented for the first time. The diffusion values in liquid ethanol were measured by the Taylor dispersion method at temperatures from 298.15 K to 333.15 K and pressures from 0.10 MPa to 30.00 MPa. Those in supercritical CO2 were carried out by the chromatographic impulse response method at 308.15 K–353.15 K and up to 40.00 MPa. The determined diffusion activation energies in supercritical CO2 were Ea =18.6 kJ/mol to 11.0 kJ/mol at P = 15.00 MPa to 35.00 MPa, and those in liquid ethanol were Ea =16.3 kJ/mol to 15.1 kJ/mol at P = 0.10 MPa to 30.00 MPa, respectively. All the diffusion data of ibuprofen in liquid ethanol and in supercritical CO2 were well correlated by the hydrodynamic equation proposed in this study, with an average absolute relative deviation of 2.2 % for 115 data points.