Freezing Delay Mechanism and Macroscopic Performance

Icephobic surfaces, intended as passive anti-icing materials, are critically important due to the substantial costs, damage, and potential loss of equipment and lives resulting from ice formation on outdoor surfaces. The practical design of these surfaces necessitates a comprehensive understanding of ice formation processes and the dynamics of ice propagation across surfaces. Ice nucleation and the subsequent interdroplet freezing are pivotal in initiating and achieving complete ice coverage, respectively. Analyzing these phenomena, in conjunction with their interactions with the substrate and environmental conditions, is essential for advancing the design of surfaces with enhanced icephobic performance. This chapter systematically explores the mechanisms of ice nucleation, including nucleation rates, preferred nucleation sites, and favorable freezing pathways such as desublimation and condensation-freezing on superhydrophobic surfaces. Additionally, considering that ice propagation over a substrate plays a more critical role in achieving full surface coverage than ice nucleation, this chapter delves into potential mechanisms of ice propagation, theoretical frameworks, and strategies to control this process through surface engineering.