CO_2膨胀液体的分子动力学模拟  

Molecular Dynamics Simulation of CO_2-Expanded Liquids

作　　者：王伟彬[1] 银建中[1] 

机构地区：[1]大连理工大学化工学院,辽宁大连116012

出　　处：《高压物理学报》2010年第4期271-278,共8页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(20976028);大连理工大学人才基金(893340)

摘　　要：采用分子动力学方法,模拟了CO2膨胀甲醇体系、CO2膨胀乙醇体系的热力学性质和输运性质,以及对氯硝基苯在CO2膨胀甲醇体系、苯甲腈在CO2膨胀乙醇体系中的扩散性质。CO2膨胀甲醇体系的密度模拟值略高于实验值,而CO2膨胀乙醇体系的密度模拟值与实验值非常接近。模拟结果表明:CO2使甲醇和乙醇溶液的膨胀非常明显,当CO2的摩尔分数达到0.5时,溶液膨胀约100%;得到了CO2、甲醇、乙醇、对氯硝基苯以及苯甲腈的扩散系数,其中对氯硝基苯和苯甲腈在两种膨胀液体中的扩散系数与实验结果接近;通过扩散系数关联了两种膨胀液体的粘度,计算结果与修正的Wilke-Chang方程得到的体系粘度规律一致。Thermodynamic and transport properties of CO2-expanded methanol system and CO2-expanded ethanol system,as well as the diffusivities of p-chloronitrobenzene/CO2-expanded methanol system and benzonitrile/CO2-expanded ethanol system were modeled with molecular dynamics simulation method.The density data obtained in CO2-expanded methanol system are slightly higher than the experimental ones,while that achieved from CO2-expanded ethanol system are very close to the experimental results.Simulation results show that the volume of methanol or ethanol solutions can be expanded significantly by CO2.When the mole fraction of CO2 reaches 50%,the volume swelling of the solution is 100%.In addition,the diffusion coefficients of CO2,methanol,ethanol,p-chloronitrobenzene and benzonitrile were simulated,in which p-chloronitrobenzene and benzonitrile are similar to experimental data.Finally,viscosities of two expanded liquids are correlated by their diffusion coefficients,which is in agreement with the calculated results of modified Wilke-Chang equation.

关 键 词：CO2膨胀液体 分子动力学模拟 热力学平衡性质 输运性质 

分 类 号：O642[理学—物理化学] O521.2[理学—化学]