FLUID FLOW IN NANOTUBES - Foundations of Nanotechnology: Pore Size in Carbon-Based Nano-Adsorbents - page 206

considered here the pressure gradient (0 - 3).10 9 atm/m Q ( pl/sek = 10 -15 m 3 / sek )
is directly proportional to

∂ / . Coordinates of chirality for each CNT are indi-
cated in the figure legend. The linearity of the relations between flow and pressure
gradient confirms the validity of calculations of the Eq. (4.3).

p ∂ z

FIGURE 4.5 Relationship between volumetric liquid flow rate in carbon nanotubes with
different diameters and applied pressure gradient

Figure. 4.6 shows the profile of the radial velocity of water particles in the
CNT with diameter 2.77 nm. The vertical dotted line at 1.38 nm marked surface
of the CNT. It is seen that the velocity profile is close to a parabolic shape.
In contrast to previous work [74], the flow of water under a pressure gradient
considered in the single-walled nanotubes of “chair” type of smaller radii: 0.83,
0.97, 1.10, 1.25, 1.39 and 1.66 nm.
Figure 4.7 shows the dependence of the mean flow velocity v on the applied
pressure gradient

P /D in the long nanotubes is equal to 75 nm at 298 K. A simi-
lar picture pattern occurs in the tube with the length of 150 nm.

L