Densities, viscosities and excess properties of bis-2,4,4-trimethylpentylphosphinic acid (Cyanex 272)Â +Â diluent binary mixtures at 298.15Â 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 (VmE), excess viscosities (ηE), excess Gibbs energy of activation of flow (ΔGE) 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, ΔGE, ηE or VmE and the Cu++/Fe3+ extraction characteristics with BTMPPA is noticed.