Ultralong Polarization Chains Induced by Ions Solvated in Confined Water Monolayers

We disclose by classical molecular dynamics simulations the formation of long polarization chains induced by ions solvated in a water monolayer confined between graphene sheets. First, we examine the dynamics of confined pure water clusters with Nw < 100 at temperatures of 200–300 K. We show that for certain "magic" Nw the clusters form crystallites with stable structures, where discrete water rings are self-organized with clockwise or anticlockwise orientations of their dipoles. Next, we show that when ions are hydrated in larger clusters with a "bracketed" crystal structure, they can generate long fluctuating chains of (Nw > 30) polarized waters. The chains generated by opposite charged ions can eventually meet, lock, and stay polarized at room temperatures.