基于TraPPE-UA势能模型的超高压乙醇分子动力学模拟  

Molecular dynamics simulation of ethanol under ultrahigh pressure based on TraPPE-UA potential energy model

作　　者：周晓平[1] 周伟[1] 郝江涛[1] 

机构地区：[1]郑州大学西亚斯国际学院

出　　处：《中国测试》2018年第1期44-48,100,共6页China Measurement & Test

基　　金：河南省科技攻关计划项目(162102210316);河南省基础与前沿技术研究计划项目(162300410269)

摘　　要：采用分子动力学方法,将Tra PPE-UA模型应用于乙醇分子动力学模拟,分析温度298~500 K,压强10~300 MPa下乙醇的热力学性质、结构性质和动力学性质,模拟结果与文献模拟值吻合较好。通过对体系径向分布函数的研究,发现在压强很大的情况下,乙醇体系的结构依然很有规律。研究表明,随温度的升高,乙醇体系焓值增大;随着压强和温度的升高,各径向分布函数的第1峰高度明显下降,体系的长程有序程度下降;乙醇的自扩散系数随温度的升高而增大,而压强对扩散系数的影响与温度正好相反。The thermodynamic properties, structure and dynamic properties of ethanol under the temperature of 298-500 K and pressure of 10-300 MPa were investigated by the use of molecular dynamics （MD） simulations and the TraPPE-UA model to describe the ethanol molecule. The simulation results agree well with those from previous molecular simulations. Through the study on the radial distribution function of the system, it is found that the structure of the ethanol system remains regular under the large pressure. From the results, it can be seen that the enthalpy of ethanol system increases as the temperature rises; with the increase of pressure and temperature, the first peak height of each radial distribution function decreases obviously and the long-range orderness of the system decreases as well; and the self-diffusion coefficient of ethanol increases as the temperature rises, while the impact of pressure on diffusion coefficient is just opposite to that of temperature.

关 键 词：乙醇 势能模型 焓 径向分布函数 扩散系数 

分 类 号：TQ223.122[化学工程—有机化工]