Differential permeability of a rectangular stacking of nanotubes with open tips

The paper proposes an evaluation scheme of differential permeability of a layer composed of carbon nanotubes with open tips on the basis of Newtonian mechanics. This idea is based on the method of equivalent uniform layer. Averaging of interaction energy is performed along the flat elementary cell located perpendicularly to the axis of the tubes. The entire surface of the permeable layer is parqueted with such cells. Low-energy molecules do not pass the uniform layer. However, at a certain speed, the stacking of nanotubes becomes permeable. The determined minimum speed and the Maxwell distribution allow obtaining the percentage of molecules that have passed through the layer of the stacking tubes. In this work, a single-parameter rectangular stacking of nanotubes is considered. For this case, the permeability curves have been plotted. Based on the calculations, it has been stated that the permeability of the system of parallel nanotubes with open tips does not depend on their length and it is defined by the inlet profile of the averaged interaction energy of the tube’s stacking. Therefore, the profile under adiabatic conditions lack of the energy exchange with the carbon atoms of tube crystal structure) is invariant with respect to longitudinal dimensions of the tube and symmetrical with respect to the input–output positions. In this regard, the permeability has been found to be dependent only on the transverse dimension of the tubes and the ratio of their convergence.