Characterizing Surface Ice-philicity Using Molecular Simulations and Enhanced Sampling

The formation of ice, which plays an important role in diverse contexts, ranging from cryopreservation to atmospheric science, is often mediated by solid surfaces. Although surfaces that interact favorably with ice (relative to liquid water) can facilitate ice formation by lowering nucleation barriers, the molecular characteristics that confer a surface with "ice-philicity" are complex and incompletely understood. To address this challenge, here we introduce a robust and computationally effcient method for characterizing surface ice-philicity, which combines molecular simulations and enhanced sampling techniques to quantify the free energetic cost of increasing surface-ice contact at the expense of surface-water contact. Using this method to characterize the ice-philicity of a family of model surfaces that are latticed matched with ice but vary in their polarity, we find that the non-polar surfaces are moderately ice-phobic, whereas the polar surfaces are highly ice-philic. In contrast, for surfaces that display no complementarity to the ice lattice, we find that ice-philicity is independent of surface polarity and that both non-polar and polar surfaces are moderately ice-phobic. Our work thus provides a prescription for quantitatively characterizing surface ice-philicity and sheds light on how ice-philicity is infuenced by lattice matching and polarity.