FLUID FLOW IN NANOTUBES - Foundations of Nanotechnology: Pore Size in Carbon-Based Nano-Adsorbents - page 205

There are three importantfeatures inthe results:
(1) the enhancement of the flow decreases with increasing diameter of the
CNT.
(2) with increasing diameter, the value tends to the theoretical value of

s L = 30 nm and the effective viscosity

Eqs. (4.4) and (4.5) with a slip

m d . The dotted line showed the curve of 15% in the second error
in the theoretical data of viscosity and slip length.
(3) the change e in diameter of CNTs cannot be explained only by the slip
length.
To determine the dependence the volumetric flow of water from the pressure
gradient along the axis of single-walled nanotube with the radii of 1.66, 2.22,
2.77, 3.33, 3.88, 4.44 and 4.99 nm in Thomas John and McGaughey Alan [73],the
method of molecular modeling was used. Snapshot of the water-CNT is shown
in Fig. 4.4.
Figure 4.4 shows the results of calculations to determine the pressure gradient
along the axis of the nanotube with the diameter of 2.77 nm and a length of 20 nm.
Change of the density of the liquid in the cross sections was less than 1%.

( )

= m

∞

FIGURE 4.4 Axial pressure gradient inside the 2.77 nm diameter CNT [73].

Figure 4.5 shows the dependence of the volumetric flow rate from the pressure
gradient for all seven CNTs. The flow rate ranged from 3-14 m/sec. In the range