Theory of the force of Friction Acting on Water Chains Flowing through Carbon Nanotubes

A simple model for the friction experienced by the one dimensional water chains that flow through subnanometer diameter carbon nanotubes is studied. The model is based on a lowest order perturbation theory treatment of the friction experienced by the water chains due to the excitation of phonon and electron excitations in both the nanotube and the water chain, as a result of the motion of the chain. The resulting dynamics of the chain due to an applied pressure are determined by a solution of the Fokker-Planck Equation. On the basis of this model, we are able to demonstrate that the observed flow velocities of water chains through carbon nanotubes of the order of several centimeters per second can be accounted for. If the hydrogen bonds between the water molecules are broken (as would occur if there were an electric field oscillating with a frequency equal to the resonant frequency of the hydrogen bonds present), it is shown that the friction experienced by the water flowing in the tube can be much smaller.