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 structure, 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 molecules 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.