Di Novo Nicolò Giuseppe, Bagolini Alvise, Pugno Nicola Maria
Laboratory of Bioinspired, Bionic, Nano, Meta, Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano, 77, 38123 Trento, Italy.
Sensors and Devices Center, Bruno Kessler Fundation, Via Sommarive 18, 38123 Trento, Trento, Italy.
iScience. 2024 Sep 27;27(10):111056. doi: 10.1016/j.isci.2024.111056. eCollection 2024 Oct 18.
Fascinated by the purple color, water-repellent, and self-cleaning properties of leaves, we studied their morphology, wetting, and condensation frosting. Wax nanotubules confer high contact angles, enabling coalescence-induced condensation droplet (out-of-plane) jumping, which, as known, contributes to slowing down frost. Another type of movement-this time in-plane-becomes predominant in reducing the frosting velocity ( ) within a sub-cooling temperature range. Specifically, supercooled droplets slide toward the frost bridges upon contact, moving in the opposite direction to frost propagation. Between -11 and -2°C, Sliding on Frost (SoF) shifts from being rare to very frequent, reducing from approximately 4 to 1, respectively. Using high-speed microscopy, we observed that the advancing contact angle of supercooled water on ice decreases with temperature. We describe the primary role of this behavior in SoF with a model that accounts for the forces involved and explains the observed transition.
受树叶的紫色、拒水和自清洁特性的吸引，我们研究了它们的形态、润湿性和凝结结霜情况。蜡质纳米管赋予了高接触角，使得聚结诱导的凝结液滴（面外）跳跃成为可能，如我们所知，这有助于减缓结霜。另一种运动——这次是面内运动——在亚冷却温度范围内降低结霜速度（ ）时变得占主导地位。具体而言，过冷液滴在接触时会朝着霜桥滑动，其移动方向与霜的蔓延方向相反。在 -11°C 至 -2°C 之间，霜上滑动（SoF）从罕见变得非常频繁， 分别从约 4 降至 1。通过高速显微镜观察，我们发现过冷水在冰上的前进接触角随温度降低。我们用一个模型描述了这种行为在 SoF 中的主要作用，该模型考虑了相关力并解释了观察到的转变。
