Water diffusivity in a mixed phase binary system: Effective water diffusion coefficients in tetradecanol-eicosanol mixtures

Widmer, DR; Calhoun, DF; Thurston, D; Edwards, AM

HERO ID

4937214

Reference Type

Journal Article

Year

2014

Language

English

HERO ID 4937214
In Press No
Year 2014
Title Water diffusivity in a mixed phase binary system: Effective water diffusion coefficients in tetradecanol-eicosanol mixtures
Authors Widmer, DR; Calhoun, DF; Thurston, D; Edwards, AM
Journal Fluid Phase Equilibria
Volume 379
Page Numbers 157-166
Abstract Fourier-transform infrared attenuated total reflection spectroscopy is used to measure the effective water diffusion coefficients in pure tetradecanol between 313 K and 338 K and in liquid and liquid-solid mixtures of tetradecanol (C14H29OH) and eicosanol (C20H41OH) at 313K. The temperature dependent data in tetradecanol yields an activation energy for diffusion higher than that measured in pure alkanes. This is consistent with the critical role hydrogen bonds play in diffusion. Differential scanning calorimetry and infrared spectroscopy are used to construct the solid-liquid phase diagram for the tetradecanol-eicosanol system. Diffusion measurements in these mixtures are linked to the experimental phase diagram. Water diffusivity in liquid mixtures at low eicosanol concentrations (80 to 100 mol percent tetradecanol) suggests that the measured diffusion coefficient of water is independent of the mixture's bulk viscosity. We find a six-fold decrease in water diffusivity when the solid fraction of the equilibrium mixture increases from zero to thirty percent. The decrease in water diffusivity results from a longer diffusion path length caused by solid portions of the mixture acting as barriers to diffusion. (C) 2014 Elsevier B.V. All rights reserved.
Doi 10.1016/j.fluid.2014.07.021
Wosid WOS:000342243900017
Is Certified Translation No
Dupe Override Yes
Is Public Yes
Language Text English
Keyword Water diffusion; Solid-liquid equilibrium; Fourier-transform infrared spectroscopy (FTIR); Differential scanning calorimetry; Fatty alcohol mixtures
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