Electrostatic Jumping of Frost
Electrostatic Jumping of Frost
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DOI：
10.1021/acsnano.0c09153
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发表时间：
2021-02-24
期刊：
影响因子：
17.1
通讯作者：
Boreyko, Jonathan B.
中科院分区：
文献类型：
--
作者：
Mukherjee, Ranit;Ahmadi, S. Farzad;Boreyko, Jonathan B.
自1940年以来，冰的带电一直是研究的主题，主要是在雷暴中产生电荷的背景下进行的。这种电荷的产生是自发的，不同于施加外部电场来影响冰晶的扩散生长。在这里，我们利用冰的自发带电来揭示一个令人惊讶的现象，即冰霜树枝跳跃。我们使用侧视高速成像来实验地观察到霜冻树枝从母枝晶和/或基质上脱落，跳出平面朝向相反的极地液体。在此基础上，建立了计算结霜枝晶与液体之间引力的解析模型和数值模型，与实验结果吻合较好。这些模型估计了不断增长的霜层内电荷分离的程度，这是由于冰中电荷载流子的迁移率不匹配造成的。我们的发现表明，意外的跳霜事件可以作为一个模式系统来解决大气物理中关于冰中电荷分离的长期问题，同时也具有作为除冰结构的潜力。
The electrification of ice has been a subject of research since 1940, mostly in the context of charge generation in thunderstorms. This generation of electric charge is spontaneous, distinct from applying an external electric field to affect the diffusive growth of ice crystals. Here, we exploit the spontaneous electrification of ice to reveal a surprising phenomenon of jumping frost dendrites. We use side-view high-speed imaging to experimentally observe frost dendrites breaking off from mother dendrites and/or the substrate to jump out-of-plane toward an opposing polar liquid. Analytical and numerical models are then developed to estimate the attractive force between the frost dendrites and liquid, in good agreement with the experimental results. These models estimate the extent of charge separation within a growing sheet of frost, which is caused by mismatches in the mobilities of the charge carriers in ice. Our findings show that the unexpected jumping frost event can serve as a model system for resolving long-standing questions in atmospheric physics regarding charge separation in ice, while also having potential as a deicing construct.