The influence of molecular orientation on the ability of water to enter a carbon nanotube at different temperatures

Temperature plays a significant role in determining the dynamics of flow on the nanoscale. This is particularly important with carbon nanotubes, which are likely to form an integral part of future nanofluidic and biological devices. We demonstrate through first-principles density-functional theory (DFT) that the orientation of the individual water molecules plays a significant role in determining the temperatures and energies at which water is able to enter the nanotube. This has a number of implications for the flow of water through the nanotube at different temperatures and densities, particularly when considering low-density water vapour.