Microscopic insights into wetting-like spatiotemporal evolution of spontaneous ice and its tribological behavior

The lubrication process of ice has been an elusive problem for centuries. Here, we report a wetting-like state before the pressure melting in ice friction processes through molecular dynamics simulations of spontaneous ice. Ice wetting, exhibiting spatiotemporal evolution, is influenced by the wettability of the solid plate, ice temperature, and compression method. Hot ice (270 K) will expand, wet, and reconstruct to form a quasi-liquid layer when the solid plate is close to ice. Cold (200 K) ice only expands and exhibits elasticity that satisfies Hooke's law when adsorbed and compressed on the plate. Ice wetting and low friction coefficient (< 0.01) occur under the same conditions, which indicates that ice wetting is a precursor condition for ice slip.