Molecular dynamics （MD） simulations are performed to study the structure and adsorption of ethanol/water mixture within carbon nanotubes （CNTs）. Inside the （6,6） and （10,10） CNTs, there are always almost full ...Molecular dynamics （MD） simulations are performed to study the structure and adsorption of ethanol/water mixture within carbon nanotubes （CNTs）. Inside the （6,6） and （10,10） CNTs, there are always almost full of ethanol molecules and hardly water molecules. Inside wider CNTs, there are some water molecules, while the ethanol mass fractions inside the CNTs are still much higher than the corresponding bulk values. A series of structural analysis for the molecules inside and outside the CNTs are performed, including the distributions of radial, axial, angular density, orientation, and the number of hydrogen bonds. The angular density distribution of the molecules in the first solvation shell outside the CNTs indicates that the methyl groups of ethanol molecules have the strongest interaction with the carbon wall, and are pinned to the centers of the hexagons of the CNTs. Based on the understanding of the microscopic mechanism of these phenomena, we propose that the CNTs prefer to contain ethanol rather than methanol.展开更多
基金V. ACKNOWLEDGMENTS This work is supported by the National Natural Science Foundation of China （No.20603032 and No.20733004）, the Ministry of Science and Techology of China （No.2011CB921400）, the Foundation for the Author of National Excellent Doctoral Dissertation of China （No.200736）, the Fundamental Research Funds for the Central Universities （No.WK2340000006 and No.WK2060140005）, and the Shanghai Supereompnter Center, the USTC-HP HPC Project, and the SCCAS.
文摘Molecular dynamics （MD） simulations are performed to study the structure and adsorption of ethanol/water mixture within carbon nanotubes （CNTs）. Inside the （6,6） and （10,10） CNTs, there are always almost full of ethanol molecules and hardly water molecules. Inside wider CNTs, there are some water molecules, while the ethanol mass fractions inside the CNTs are still much higher than the corresponding bulk values. A series of structural analysis for the molecules inside and outside the CNTs are performed, including the distributions of radial, axial, angular density, orientation, and the number of hydrogen bonds. The angular density distribution of the molecules in the first solvation shell outside the CNTs indicates that the methyl groups of ethanol molecules have the strongest interaction with the carbon wall, and are pinned to the centers of the hexagons of the CNTs. Based on the understanding of the microscopic mechanism of these phenomena, we propose that the CNTs prefer to contain ethanol rather than methanol.
