中文摘要：

基于经典的分子动力学模拟方法,研究了不同的超临界CO2（scCO2）溶剂密度下,金纳米颗粒周围溶剂分子的结构与动力学性质。结果表明,由于金纳米颗粒对scCO2溶剂分子有较大的吸引作用,使scCO2分子紧密地围绕在其表面周围并形成了两个较明显的溶剂层。随着溶剂密度的增加,纳米颗粒在scCO2中的溶剂化程度会减小。通过分析固液界面不同区域内scCO2分子的均方位移及停留时间分布,考察了界面CO2分子的传递性质。研究结果将对金属纳米颗粒在超临界二氧化碳中溶剂化结构和性质提供微观机理。

英文摘要：

Classical molecular dynamics（MD）simulations were carried out to explore the structural and dynamical properties of supercritical CO2（scCO2）near the Au nanoparticle under various fluid densities.The simulation results show that the gold-CO2 interaction plays a major role and the CO2 molecules surrounding the Au nanocrystal surface form a well-defined two-region solvation layer.As the solvent density increases,the solvation degree of Au nanoparticle decreases.By analyzing the mean square displacement and occupation time distribution in the interfacial region of Au-CO2,the interfacial dynamical properties of scCO2 molecules were investigated.The resuls are expected to provide the microscopic mechanism of solvation behavior of nanoparticles in scCO2 fluid.