Transport diffusion in deformed carbon nanotubes

Deformation Effect on Water Transport through Nanotubes

“…LJ-potential is used to describe the interactions between the water molecules and the interaction between the CNT and water molecules. The LJ-potential is given by the following equation: The perfect (6,6) CNT has a radius of 4.068 Å and bond length of 1.421 Å, whereas a perfect (6,6) BNNT has a radius of 4.211 Å and bond length of 1.47 Å. The description of the dimensions of the nanotubes is given in Table 1.…”

“…This is due to the increase in the pore volume of the elliptical crosses section of the nanotubes, which facilitates the accommodation of water molecules side by side inside the pore. Usually, a single-file water transport is observed in nanotubes in (6,6) nanotubes, but when they are distorted in XY-direction, it has sufficient space to accommodate two water molecules side by side, as shown clearly in the Figure 3. For both the CNT and BNNT, we can see a significant increase in the hydrogen bond, which decreases the mobility and formation of the more-bonded system.…”

“…The Z-distortion is induced in the perfect nanotube either by stretching or compressing along Z-axis, which increases or decreases the length of the nanotube, respectively. The stretch factor is given by Z'/Z 0 , where Z' is the total length after the perfect nanotube is distorted in the Z-direction [6]. The Z-distorted nanotube is shown in Figure 2b.…”

“…He et al [5] studied the effects of deformation degree and about the location of deformation in the carbon nanotubes on water transport. Feng et al [6] showed that the transport diffusion of helium gas through deformed carbon nanotubes with screw deformation did not have any effect, while the XY-distortion and Z-distortion showed that the effect on transport diffusion is significant with an increase in temperature and distortions values. Even though there were earlier studies carried out on the water transport phenomena through deformed carbon nanotubes, water transport through nanotubes that have a twist or XY-distortion and Z-distortion have not been studied extensively yet.…”

“…Figure 1 shows the schematic of the molecular dynamics setup used in this study for CNT and BNNT. In this study, we used CNTs and BNNTs with chirality (6,6) and length 100 Å in all simulations. As the Z-distortion name suggests, the nanotube deformation is along the Z-direction; hence, a nanotube of length 100 Å gets distorted to 90, 110, and 120 Å for distortion values of 0.9, 1.1, and 1.2, respectively.…”