Molecular Dynamics Investigation of Static and Dynamic Interfacial Properties in Ice-Polymer Premelting Layers

Premelting at the ice-polymer interfaces, in which a quasi-liquid layer (QLL) forms below the melting point, is strongly influenced by polymer surface chemistry; however, the molecular-scale mechanisms underlying these effects remain poorly understood. This study employs large-scale molecular dynamics simulations combined with machine learning-assisted analysis to elucidate how polymer type (hydrophilic vs hydrophobic) modulates interfacial premelting. Our simulations reveal that hydrophilic and hydrophobic polymer surfaces have distinct effects on the QLL thickness, interfacial water structure, and diffusivity. Specifically, a hydrophilic polymer interface promotes a thicker QLL with more ordered interfacial water and lower diffusivity, whereas a hydrophobic interface induces a thinner QLL with a less ordered interfacial water structure and higher diffusivity. These results advance the understanding of polymer-mediated interfacial melting phenomena and offer guidance for designing anti-icing and low-friction materials.