Diffusion Coefficients of Organic Compounds at Infinite Dilution in Mixtures Involving Associating Compounds. Experimental Determination and Modeling by Group Contribution Methods

Abstract

Diffusion coefficients of aromatic compounds at infinite dilution in binary mixtures have been measured at 298.15 K with respect to composition using the Taylor dispersion technique. The binary mixtures considered in this work were from alcohols (methanol, ethanol) and acetone with hexane, heptane, cyclohexane, carbon tetrachloride, and chloroform; the aromatic compounds were benzene, benzaldehyde, acetophenone, and phenol. The purpose of this work was to study the influence of the polarity of the binary mixtures on diffusion coefficients. The data were correlated by the Leffler−Cullinan equation, using the measured values of diffusion coefficients in pure solvents and estimating the viscosity of the binary mixtures with group contribution methods. Special attention was paid to the capability of models to take into account the polarity of the mixtures; for this purpose, in addition to the Grunberg−Nissan model, the UNIFAC-VISCO group contribution method was also considered.

Diffusion Coefficients of Organic Compounds at Infinite Dilution in Ternary Mixtures: Experimental Determinations and Modeling

“…The Taylor dispersion technique was used to determine diffusion coefficients in ternary solvents. The experimental apparatus and procedures for the measurement of diffusion coefficients of solutes in binary solvents have been described in previous papers. ,,, A model 655A liquid chromatographic pumping system (Merck-Hitachi) was used to provide constant laminar flow at 0.1 mL·min −1 . The diffusing tube (a stainless steel pipe) was 10 000 cm long with an inner diameter of d tube = 0.0476 cm and coil diameter of d coil = 22 cm.…”

“…When these data are not available, the use of reliable predictive correlations is required. For this purpose, a comparison was performed , between the Grunberg−Nissan and universal functional activity coefficient (UNIFAC-VISCO) , group contribution methods. Both models yielded satisfactory results for binary hydrocarbon solvents and turned out to be less accurate for polar and associating compounds.…”

Diffusion coefficients of nickel chloride in aqueous solutions of lactose at T=298.15K and T=310.15K

“…The theory of the Taylor dispersion technique is well described in the literature [28][29][30][31][32][33][34][35][36][37], and so the authors only indicate some relevant points concerning this method on the experimental determination of binary diffusion coefficients and ternary diffusion coefficients, respectively.…”

Active Learning Accelerates Ab Initio Molecular Dynamics on Pericyclic Reactive Energy Surfaces

“…The Langevin friction coefficient was estimated using the experimental diffusion coefficient of benzene in cyclohexane (1.92 cm 2 s −1 ), chloroform (2.89 cm 2 s −1 ) and acetone (4.25 cm 2 s −1 ). 72 The associated friction coefficients were calculated using Equation 1, where γ is the friction coefficient, k B is the Boltzmann constant, and D is the diffusion coefficient.…”