Fig. 15 Water distribution in EMD and NEMD simulations in 5 nm PH (left) and HH (right) nanopore. Hydrocarbons are not presented for clearance. It indicates that the water bridge breaks down during flow in the NEMD simulation in the HH nanopore, demonstrating that the strength of hydrogen bond is weak to persist the water bridge. However, in PH nanopore, with the assistance of electric field, the water bridge persists in NEMD simulations.