β-二酮在水/超临界二氧化碳界面的分子动力学模拟(英文)

• 作 者: 刘淑延 柴景春 杨晓宁
• 机 构: School of Mechanical and Power Engineering,Nanjing University of Technology,State Key Laboratory of
• 出 处: Chinese Journal of Chemical Engineering
• 发表日期: 2009年06期
• 关键词: preference supercritical 动力学模拟 translational somewhat chelating β-二酮 solute anis

The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations.The TIP3P potential is used for water and the EPM2 model is for CO2.The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface.The two chelating molecules show interfacial preference.Comparatively,the AA molecules show somewhat more preference for interfacial region,whereas the HFA molecules are preferably near the Sc-CO2 phase.The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface.It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.The anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.

The structural and dynamical properties of hexafluoroacetylacetone (HFA) and acetylacetone (AA) at the water / supercritical CO2 (Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations. The TIP3P potential is used for water and the EPM2 model is for CO2. The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface. Two chelating molecules show interfacial preference. Comparatively, the AA molecules show somewhat more preference for interfacial region, but the HFA molecules are preferably near the Sc-CO2 phase. The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface. It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.Th e anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.