Fig. 2 Illustration of the illite-slit pore in potassium-hydroxyl (P-H) and hydroxyl-hydroxyl (H-H) configuration with a pore width of 5 nm. Color codes are as in Fig.1 . The configurations with 10 nm and 15 nm pore width are not shown but are used in this study.
We construct seven models with different water concentrations for each of the three slit pore widths. Table S-1 in Supporting Information summarizes all the 21 P-H models. We construct 21 additional MD models with the H-H configuration that are also listed in Table S-1. In the interests of space, we only show the initial configurations of the P-H models with a pore width of 5nm in Fig. 3.
The temperature and pressure are kept constant at 350 K and 400 atm. In order to keep pressure conditions similar across all models, an increase in water concentration is accompanied by a decrease in the number of hydrocarbon molecules.