Physico-chemical properties of di-(2-ethylhexyl) phosphoric acid with apolar solvents from ultrasonic studies

Abstract

The ultrasonic velocity (U), viscosity (eta) and density (rho) values of binary mixtures of di-(2-ethylhexyl) phosphoric acid (D2EHPA) with three apolar solvents, namely benzene, carbon tetrachloride and n-pentane, were experimentally measured at 313.16 K. The acoustic impedance (z), isentropic compressibility (beta(s)), intermolecular free length (L-f), free volume (V-f), internal pressure (pi(i)) and viscous relaxation time (tau) were computed using the experimental data. The excess functions have been calculated and discussed in terms of nature of binary interactions. The computed results of the excess functions have been fitted to a Redlich-Kister-type polynomial equation. The results of this study indicate that the molecular interaction in the case of D2EHPA + n-pentane is the strongest.