Freezing as a Path to Build Micro-Nanostructured Icephobic Coatings

Superhydrophobic photothermal materials with the micro-nano structure are considered to be promising icephobic surfaces. Unfortunately, converting micro-nano hierarchical structure concepts into genuine synthetic materials has proven to be exceedingly expensive and difficult, partially because their sophisticated structures need construction at several length scales. Herein, a facile strategy of employing ice crystals to construct sophisticated hierarchical micro-nanostructured anti-icing composites with photothermal, self-healable, and self-cleaning properties is presented. The composites are covered with interconnected microscale pores replicated from ice crystals, which facilitates the construction of the hydrophobic or superhydrophobic properties based on the Cassie-Baxter model, endowing the coating with self-cleaning ability. Besides, by adding solar-to-heat conversation nanomaterials, the coating can implement in situ solar anti-/deicing. The abundant micropores caused by ice templates can further improve the photothermal conversion capability through multiple reflections of light. Importantly, the coating is endowed with the self-healing capability to repair hydrophobicity under sunlight. Additionally, it is demonstrated that the self-cleaning and self-healing abilities are mutually reinforcing, synergistically improving anti-/deicing performances. Overall, the presented ice-templated coating shows great potential and broad impacts owing to its inexpensive component materials, simplicity, eco-friendliness, and high energy efficiency.