The initial flow dynamics of light atoms through carbon nanotubes

Carbon nanotubes are becoming increasingly viable as membranes for application in a wide variety of nano-fluidic applications, such as nano-scale nozzles. For potential applications which utilise switching on and off of flow through nanotube nozzles, it is important to understand the initial flow dynamics. Furthermore, when the nanotube interacts strongly with the fluid, the flow may be very different from conventional simulations which consider atoms (such as argon, for example) which interact only weakly with the nanotube. In order therefore to better understand such flow and explore the potential manipulation of flow that can be achieved, we consider the initial flow dynamics of a light fluid through carbon nanotube nozzles, using nonequilibrium molecular dynamics simulations. Our studies show that if the conditions are controlled carefully, unusual phenomena can be generated, such as pulsed flow and very non-linear increases in flow rate with nanotube diameter. We detail the physical reasons behind such phenomena, and describe how the pulsation can be controlled using temperature.