A transition between bistable ice when coupling electric field and nanoconfinement

The effects of an electric field on the phase behavior of water confined inside a nanoscale space were studied using molecular dynamics simulations. It was found that the diffusion coefficient of water reaches its maximum when value of the surfaces' charge is at the threshold, q_c = 0.5e. This unexpected phenomenon was attributed to the intermediate state between two stable ice states induced by nanoconfinement and the electric field generated by charged surfaces, respectively. Our finding is helpful to understand electromelting and electrofreezing of water under nanoconfinement with the electric field.