Bio-Inspired Super-Surfaces from Frost-Assisted Freeze-Casting Strategy

Bio-inspired super-surfaces with specific wettability and optical properties are highly valuable in various applications, while their direct and simple fabrication is still a challenge. Here, it is found that polymer monomers can climb upward against gravity along the frost crystals' structures during the thermodynamic frosting process. Its mechanism is revealed and thus a novel frost-assisted freeze-casting strategy (FFCS) for dynamically customizing micro-nanostructured super-surfaces is presented. These FFCS-derived super-surfaces with frost-crystals-like hierarchical structures are obtained directly by simply in situ photocrosslinking these monomers and removing the frost crystals. It has been proved that this innovative fabrication strategy via the thermodynamic frosting phase transition process is a general approach applicable to a wide range of materials. After the integration of nanomaterials, it has been demonstrated that the treated super-surfaces simultaneously exhibited extraordinary superhydrophobicity, outstanding photothermal conversion efficiency, impressive anti-icing ability, as well as light-healing superhydrophobicity and self-cleaning capabilities. It is believed that these new finding that harnesses the thermodynamic process of frosting to fabricate materials will bring inspiration and multifaceted impacts in a variety of scenarios.