超临界NaCl水溶液的分子动力学模拟

采用分子动力学模拟的方法对超临界NaCl水溶液的微观结构进行了研究.模拟发现在所研究超临界条件下,密度的变化比温度的变化对超临界NaCl水溶液的微观结构影响更大.温度及密度对Cl－ H2O径向分布函数的影响比对Na＋ H2O径向分布函数的影响要大.超临界条件下,各gNa＋－Cl－在0.261 nm处出现峰值,表明Na＋、Cl－之间发生了离子的缔合.超临界条件下,随温度增加,缔合作用增强；随密度增加,缔合作用减弱.本文工作为建立可适用于超临界条件下的电解质热力学模型提供了依据.

Molecular Dynamics Study of Supercritical Aqueous Sodium Chloride Solutions

The microstructure of aqueous supercritical sodium chloride solution was investigated by molecular dynamics simulation.Under supercritical conditions,the effect of density on the microstructure of aqueous supercritical sodium chloride solution is more pronounced than the effect of temperature.Under supercritical conditions,the gNa+ Cl-(r)has a peak value at 0.261 nm,which indicates the association between Na+ and Cl-.The higher the supercritical temperature,the stronger the association interaction.The higher the supercritical density,the weaker the association interaction.With the increase of supercritical temperature,both the hydration factor and hydration number of Na+ and Cl- decrease.