Grain boundary premelting of monolayer ices in 2D nano-channels

We employ molecular-dynamics (MD) simulations to study grain boundary (GB) premelting in ices confined in two-dimensional hydrophobic nano-channels. Premelting transitions are observed in symmetric tilt GBs in monolayer ices and involve the formation of a premelting band of liquid phase water with a width that grows logarithmically as the melting temperature is approached from below, consistent with the existing theory of GB premelting. The premelted GB is found rough for a broad range of temperature below the melting temperature, the two ice-premelt interfaces bounding the melted GB are engaged with long wave-length parallel coupled fluctuations. Based on current MD simulation study, one may expect GB premelting transitions exist over a wide range of low dimensional phases of confined ice and shows important consequences for crystal growth of low dimensional ices.