Vo Quynh N, Hawkins Cory A, Dang Liem X, Nilsson Mikael, Nguyen Hung D
Department of Chemical Engineering and Materials Science, University of California, Irvine , Irvine, California 92697, United States.
J Phys Chem B. 2015 Jan 29;119(4):1588-97. doi: 10.1021/jp510365c. Epub 2015 Jan 17.
Tri-n-butyl phosphate (TBP) is an important extractant used in the solvent extraction process for recovering uranium and plutonium from used nuclear fuel. An atomistic molecular dynamics study was used to understand the fundamental molecular-level behavior of extracting agents in solution. Atomistic parametrization was carried out using the AMBER force field to model the TBP molecule and n-dodecane molecule, a commonly used organic solvent. Validation of the optimized force field was accomplished through various thermophysical properties of pure TBP and pure n-dodecane in the bulk liquid phase. The mass density, dipole moment, self-diffusion coefficient, and heat of vaporization were calculated from our simulations and compared favorably with experimental values. The molecular structure of TBPs in n-dodecane at a dilute TBP concentration was examined based on radial distribution functions. 1D and 2D potential mean force studies were carried out to establish the criteria for identifying TBP aggregates. The dimerization constant of TBP in the TBP/n-dodecane mixture was also obtained and matched the experimental value.
磷酸三丁酯（TBP）是一种重要的萃取剂，用于从用过的核燃料中回收铀和钚的溶剂萃取过程。采用原子分子动力学研究来理解溶液中萃取剂的基本分子水平行为。使用AMBER力场进行原子参数化，以模拟TBP分子和正十二烷分子（一种常用的有机溶剂）。通过纯TBP和纯正十二烷在本体液相中的各种热物理性质完成了优化力场的验证。从我们的模拟中计算了质量密度、偶极矩、自扩散系数和汽化热，并与实验值进行了良好的比较。基于径向分布函数研究了稀TBP浓度下正十二烷中TBP的分子结构。进行了一维和二维势能平均力研究，以建立识别TBP聚集体的标准。还获得了TBP/正十二烷混合物中TBP的二聚常数，并与实验值相符。
