Icing of water on polyethylene surfaces

Abstract Previous studies show that ice nucleation can be promoted remarkably when the structure of a solid surface matches well with the ice lattice. In this paper, we show that this kind of match needs not to be established directly between the solid surface and the ice. By using molecular dynamics simulation technique, we investigate the electrofreezing of liquid water on polyethylene surfaces. Two kinds of surfaces are modeled with the (1 0 0) and (0 1 0) faces of the polyethylene crystal. As exposed to the electric field, a slice of quasi-ice layer (QIL) consisting of two highly ordered layers of water molecules forms in the vicinity of the polyethylene surface. The results show that the structural difference between the solid surface and the ice lattice can be relaxed through the QIL. If the structural deviation is relatively small, as on (1 0 0) surface, the structural match can be established directly between the QIL and the bulk ice. In this situation, the nucleation is observed to be highly promoted. On the contrary, as on (0 1 0) surface, the structural deviation between the surface and the bulk ice is too large to be relaxed through the QIL, an additional liquid-like layer connecting the bulk ice and the QIL is formed. In this condition, the promotion of ice nucleation is unobservable.