Diffusivities of metal acetylacetonates in liquid ethanol and comparison with the transport behavior in supercritical systems

Abstract

Diffusion coefficients of chromium(III) acetylacetonate, palladium(II) acetylacetonate, nickel(II) acetylacetonate, vanadyl(II) acetylacetonate, and titanium(IV) oxyacetylacetonate in liquid ethanol were measured by chromatographic peak broadening method (CPB) over the range of temperature 303.15–333.15 K at atmospheric pressure. The dependencies of upon temperature and Stokes–Einstein coordinates were examined in detail. Moreover, the experimental data were modeled using nine equations from the literature to test their accuracy and prediction ability. The lower deviations were achieved by the 2-parameter correlation of Dymond-Hildebrand-Batschinski (0.32–2.17 %), the 1-parameter correlation of Tracer Liu-Silva-Macedo (1.58–3.88 %), and the 2-parameter correlations of Magalhães et al. (0.55–2.32 %). Finally, the proposed correlation based on hydrodynamic approach was found to well represent palladium(II) acetylacetonate and chromium(III) acetylacetonate systems in supercritical carbon dioxide and liquid ethanol, with the average absolute relative deviation of 3.15 and 5.02 %, respectively.