3. Equilibrium Configurations of Fluid in PH and HH Pore
Systems
Fig. 4 presents the equilibrium
configurations of water and hydrocarbon and number density profiles
(along z-direction) in 5 nm HH (Fig.4a-b) and PH (Fig. 4c-d) nanopores.
We do not show the illite structure for clarity.
Fig. 4a shows a water film adjacent to the clay surfaces in the HH pore
system. Water preferentially adsorbs on the surfaces because of the
significant electrostatic force and hydrogen bond between water
molecules and the surfaces75. This observation is
analogous to water adsorption in silica-based pore
structures69,76. Increasing the water concentration to
58.82% as shown in Fig.4b leads to an increase in the adsorbed film
thickness. The number density of water (shown in the blue line) and
hydrocarbon (black solid line) are relatively constant across the pore.