Molecular Dynamics Simulations of Tri-n-butyl-phosphate/n-Dodecane Mixture: Thermophysical Properties and Molecular Structure

Abstract

Molecular dynamics simulations of tri-n-butyl-phosphate (TBP)/n-dodecane mixture in the liquid phase have been carried out using two recently developed TBP force field models (J. Phys. Chem. B 2012, 116, 305) in combination with the all-atom optimized potentials for liquid simulations (OPLS-AA) force field model for n-dodecane. Specifically, the electric dipole moment of TBP, mass density of the mixture, and the excess volume of mixing were computed with TBP mole fraction ranging from 0 to 1. It is found that the aforementioned force field models accurately predict the mass density of the mixture in the entire mole fraction range. Commensurate with experimental measurements, the electric dipole moment of the TBP was found to slightly increase with the mole fraction of TBP in the mixture. Also, in accord with experimental data, the excess volume of mixing is positive in the entire mole fraction range, peaking at TBP mole fraction range 0.3-0.5. Finally, a close examination of the spatial pair correlation functions between TBP molecules, and between TBP and n-dodecane molecules, revealed formation of TBP dimers through self-association at close distance, a phenomenon with ample experimental evidence.

Investigation of Alcohol Conformer Distribution and Hydrogen Bonding in (2,2′-Difurylmethane + n-propanol or n-butanol) Binary Mixtures Using Molecular Dynamics Simulations

“…This inability of OPLS-AA to accurately reproduce the excess molar volume was noted in our previous study [9]. Perera et al [15] and Cui et al [16] have also reported some discrepancies with excess molar energies and excess molar volumes in their systems respectively using this force field. The calculated results however still capture the overall trend of the experimental data.…”

Determination of the Structures of Uranyl–Tri‐n‐butyl‐Phosphate Aggregates by Coupling Experimental Results with Molecular Dynamic Simulations

“…The most important difference from previously published MD simulation papers on TBP in solvent extraction organic phases– is that, in this study, the composition of the solution has been determined experimentally, even for organic phases containing uranium: TBP, water, and uranyl nitrate concentrations have been measured for each sample. The corresponding molar fractions have been used to build the starting MD simulation boxes.…”

Speciation analysis the complexation of uranyl nitrate with tri-n-butyl phosphate in supercritical CO2

“…Molecular dynamic modelling is an alternative method, which has been actively developed for liquidliquid extraction simulation. [8][9][10][11] In the liquid-liquid solvent extraction system, it is predicted that uranyl ion complexes with TBP form UO 2 $NO 3 $4TBP, UO 2 $5TBP and UO 2 $NO 3 -$3TBP$HNO 3 in the interface or in the organic phase. 12 Guilbaud et al 13 reported the aggregation of UO 2 (NO 3 ) 2 (TBP) 2 at a high uranium concentration.…”