受限于纳米碳管中的乙醇分子的结构和扩散的分子模拟研究

利用分子模拟研究了常温常压下受限于(8,8) (管径1.081 nm)和(15,15) (管径 2.035 nm)单壁纳米碳管中的乙醇分子. 对受限分子的径向密度分布和氢键等静态性质以及扩散性质进行了分析. 结果显示在管内乙醇分子的平均氢键数目和主体相一致. 乙醇分子在(8,8)碳管内具有高度有序的结构, 而在(15,15)碳管内由于空间的增大导致结构有序度的降低, 其中分子取向已呈随机分布. 进一步对扩散系数的分析发现, 在管内乙醇分子的轴向扩散系数低于主体相, 特别在(8,8)碳管内乙醇分子几乎丧失了轴向扩散能力.

Molecular Simulation Study of the Structure and Diffusion of Ethanol Molecules Confined in Carbon Nanotubes

Molecular simulations were performed to study the ethanol molecules confined in the (8,8) and (15,15) single-wall carbon nanotubes under an ambient environment. The results show that the average number of hydrogen bonds of ethanol molecules confined in these two tubes is similar to that of the bulk. The ethanol molecules confined inside the (8,8) tube were observed to have extremely highly ordered struc- ture, while the structures of the molecules in the (15,15) tube were found to be less ordered because of the expansion of inner space. Furthermore, the diffusion ability along the axial direction of the confined mole- cules was observed to be lower than the bulk phase. Especially, the ethanol molecules in the (8,8) tube were observed to keep stationary along the axial direction of the tube.