5. Single-Phase Velocity Profile Comparison between HH and PH
Pores
This section focuses on the effect of the electric field single-phase
velocities for different pore sizes for a fixed acceleration of 0.002
nm/ps2 in PH and HH pores, we compare. The results are
shown in Fig. 14 indicating that the PH nanopore exhibits flatter flow
profiles at the pore center due to the presence of the electric field as
shown in Fig.5.
Normally, adsorption is the result of van der Waals forces, covalent
bonding and electrostatic attraction92. In this work,
we do not consider covalent bonding93. Therefore, in
our study, adsorption is solely due to the van der Waals force and
electrostatic attraction. Adjacent to the surface, these forces impact
fluid transport. However, van der Waals force quickly diminish for
increasing distances from the pore surface 94, while
the electrostatic interaction force can expand more than 10
nanometers32.
Therefore, in the PH pore, fluid transport is controlled by the electric
field and imposed acceleration, leading to a flat pattern as shown in
Figs.14a-b. Increasing pore sizes for PH pores increases the width of
flat pattern as shown in Figs.14c-d because of the increase in the width
of the zone dominated by the electric field. However, in HH nanopore,
there is a negligible electric field at the nanopore center. Therefore,
classical parabolic shaped patterns are observed in HH nanopores as
shown in Fig.14.