【摘要】 采用分子动力学模拟方法研究了常温常压下水/乙醇体系的热力学性质，得到了不同浓度下二元体系的密度、自扩散系数、超额摩尔体积和径向分布函数。结果表明：随着乙醇摩尔分数的增加，二元体系的密度呈递减趋势，超额摩尔体积则先减小后增大且存在最小值，而乙醇的自扩散系数增大；结合径向分布函数分析可知，在乙醇低浓度时，水分子间的氢键网络结构较强，乙醇分子分散于其中，而随着乙醇浓度的增加，乙醇-乙醇分子之间的关联性增强，形成自己的氢键网络，而水分子仍倾向于自聚集，两种氢键网络相互交错。更多还原

【Abstract】 The thermodynamic properties of water/ethanol binary system at normal temperature and pressure were studied by molecular dynamics simulation. The density,self-diffusion coefficient,excess molar volume and radial distribution function of mixed system at different concentration were obtained. The results show that with the increase of the mole fraction of ethanol,the density of the mixed system decreases,the excess molar volume first decreases and then increases with a minimum value,and the self-diffusion coefficient of ethanol increases. Combined with the analysis of radial distribution function,it is known that when the concentration of ethanol is low,the hydrogen bonding network structure among water molecules is strong,and ethanol molecules are dispersed in it. With the increase of ethanol concentration,the correlation among ethanol molecules increases and forms their own hydrogen bonding network,while water molecules still tend to gather themselves,and the two hydrogen bonding networks are interlaced with each other.更多还原