Universal model for accurate calculation of tracer diffusion coefficients in gas, liquid and supercritical systems

authors	Lito, PF; Magalhaes, AL; Gomes, JRB; Silva, CM
nationality	International
journal	JOURNAL OF CHROMATOGRAPHY A
author keywords	Diffusion coefficient; Modeling; Non-polar systems; Polar systems; Transport properties; Universal model
keywords	TAYLOR DISPERSION TECHNIQUE; HIGH-TEMPERATURE DIFFUSION; FLUID CHROMATOGRAPHY SFC; IMPULSE-RESPONSE METHOD; LENNARD-JONES FLUID; LIMITING INTERDIFFUSION COEFFICIENTS; SLIGHTLY SOLUBLE GASES; PARTIAL MOLAR VOLUMES; HARD-SPHERE THEORY; ALPHA-AMINO-ACIDS
abstract	In this work it is presented a new model for accurate calculation of binary diffusivities (D-12) of solutes infinitely diluted in gas, liquid and supercritical solvents. It is based on a Lennard-Jones (LJ) model, and contains two parameters: the molecular diameter of the solvent and a diffusion activation energy. The model is universal since it is applicable to polar, weakly polar, and non-polar solutes and/or solvents, over wide ranges of temperature and density. Its validation was accomplished with the largest database ever compiled, namely 487 systems with 8293 points totally, covering polar (180 systems/2335 points) and non-polar or weakly polar (307 systems/5958 points) mixtures, for which the average errors were 2.65% and 2.97%, respectively. With regard to the physical states of the systems, the average deviations achieved were 1.56% for gaseous (73 systems/1036 points), 2.90% for supercritical (173 systems/4398 points), and 2.92% for liquid (241 systems/2859 points). Furthermore, the model exhibited excellent prediction ability. Ten expressions from the literature were adopted for comparison, but provided worse results or were not applicable to polar systems. A spreadsheet for D-12 calculation is provided online for users in Supplementary Data. (C) 2013 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	0021-9673
year published	2013
volume	1290
beginning page	1
ending page	26
digital object identifier (doi)	10.1016/j.chroma.2013.03.049
web of science category	Biochemical Research Methods; Chemistry, Analytical
subject category	Biochemistry & Molecular Biology; Chemistry
unique article identifier	WOS:000318377600001