Densities, viscosities and excess properties of bis-2,4,4-trimethylpentylphosphinic acid (Cyanex 272) + diluent binary mixtures at 298.15 K and atmospheric pressure

Interactions of bis-2,4,4-trimethylpentylphosphinic acid (purified Cyanex 272, BTMPPA)+diluents (n-hexane/cyclohexane/benzene/toluene/ chloroform/carbon tetrachloride/ 1,2-dichloroethane (DCE)/1-heptanol) binary mixtures have been studied in terms of densities, viscosities, excess molar volumes (V-m(E)), excess viscosities (eta(E)), excess Gibbs energy of activation of flow (Delta G(E)) at 298.15 K and atmospheric pressure. The excess properties have been fitted to the Redlich-Kister-type equation and explained in terms of interactions. Variations of these values together with the variations of Grunberg-Nissan interaction parameter (d) for BTMPPA+diluents binary systems show that BTMPPA interacts with diluents in varying degrees. However, no correlation between d, Delta G(E), eta(E) or V-m(E) and the Cu++/Fe3+ extraction characteristics with BTMPPA is noticed. (c) 2007 Elsevier B.V. All rights reserved.