Frost Halo Dynamics on Superhydrophobic Surfaces

摘要

Understanding the frosting mechanisms on solid surfaces is crucial to a broad range of industrial sectors such as aerospace, power transmission, and refrigeration. During the last few decades, extensive studies have been conducted on fundamental frosting phenomena, including ice nucleation, growth, bridging, and frost propagation, with few studies focusing on frost halo formation which has been shown to affect frosting dynamics on hydrophilic substrates. The role of frost halo dynamics formation on superhydrophobic surface remains unclear due to limited characterization in the past. Here, in order to study frost propagation dynamics, particularly freezing-induced vapor diffusion and frost halo formation, condensation frosting on highly-reflective nanostructured superhydrophobic surfaces (θ ≈ 170°) was visualized using high-speed top-view optical microscopy. Condensation frosting was initiated by cooling the surface to -20 ± 0.5℃ in atmospheric conditions (relative humidity ≈ 50% and air temperature ≈ 25℃).