Fig. 15 Water distribution in EMD and NEMD simulations in 5 nm P-H (left) and H-H (right) nanopore. Hydrocarbons are not shown for clarity. The results indicate that the water bridge breaks down during flow in the NEMD simulation in the H-H nanopore, demonstrating that the strength of hydrogen bond is not strong enough to support the water bridge. However, in P-H nanopore, with the assistance of electric field, the water bridge persists in NEMD simulations.