Ternary Diffusion Coefficients of Glycerol + Acetone + Water by Taylor Dispersion Measurements at 298.15 K

Abstract

The concentration dependence of the mutual diffusion coefficients in the ternary liquid mixture glycerol + acetone + water is determined at 298.15 K by the Taylor dispersion technique along two concentration paths of constant water mole fractions of 0.468 and 0.420, ranging from the binary subsystem toward the phase boundary in the vicinity of the critical solution point. The eigenvalues of Fick's diffusion coefficient matrix are given, and the influence of the optical properties of the system on the diffusion coefficient determination is discussed. It was found that the determinant |D| continuously declines on approaching the phase boundary.

On the interpretation of ternary diffusion measurements in low-molecular weight fluids by dynamic light scattering

“…(17) and (18). The required diffusion coefficients for this system were measured in the volume average velocity reference frame by Grossmann and Winkelmann [25]. They are converted to the molar reference frame by standard equations [23].…”

“…The matrixĜ (15) turns out to be not exactly diagonal. This is due to the inconsistency of thermodynamic [26] and diffusion [25] data. This can be shown as follows: the symmetry of the Onsager matrix L Eq.…”

“…Uncertainty in the thermodynamic factor is often large [27]. Furthermore, it has been noted that the measurement of diffusion coefficients in this system is particularly difficult [25]. The transformation with respect to the eigenvectors of the Fick matrix therefore does not lead to an exact diagonalization ofĜ.…”

“…Diffusion coefficients are predicted using the generalized Vignes' equation [23]. The required diffusivities at infinite dilution are obtained by fitting ternary diffusion data from the literature [25,31,32]. The expected prefactor ratioĜ 1 /Ĝ 2 is shown in the full composition range in Fig.…”

Densities, Viscosities, and Liquid Diffusivities in Aqueous Piperazine and Aqueous (Piperazine + N-Methyldiethanolamine) Solutions

“…Lately, the Taylor dispersion technique has also been used to determine diffusivities in ternary liquid systems. 32 In kinetic models describing aqueous solutions of (PZ + MDEA) as possible CO 2 absorbents, apparent diffusivities are used, 3,5,7,9 and multicomponent diffusion effects such as cross diffusion are thus neglected. The purpose of the present work is to determine diffusivities in the aqueous (PZ + MDEA) system to give insight into apparent diffusivities used in absorption models for these ternary systems.…”