Droplet nucleation and condensation are ubiquitous phenomena in nature and industry. Over the past century, research has shown dropwise condensation heat transfer on nonwetting surfaces to be an order of magnitude higher than filmwise condensation heat transfer on wetting substrates. However, the necessity for nonwetting to achieve dropwise condensation is unclear. This article reports stable dropwise condensation on a smooth, solid, hydrophilic surface (θa = 38°) having low contact angle hysteresis (<3°). We show that the distribution of nano- to micro- to macroscale droplet sizes (about 100 nm to 1 mm) for coalescing droplets agrees well with the classical distribution on hydrophobic surfaces and elucidate that the wettability-governed dropwise-to-filmwise transition is mediated by the departing droplet Bond number. Our findings demonstrate that achieving stable dropwise condensation is not governed by surface intrinsic wettability, as assumed for the past eight decades, but rather, it is dictated by contact angle hysteresis.

中文翻译：

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在固体亲水性表面上逐滴冷凝。

液滴成核和凝结是自然界和工业界普遍存在的现象。在过去的一个世纪中，研究表明非润湿表面上的逐滴冷凝传热要比润湿基材上的膜状冷凝传热高一个数量级。然而，不清楚不润湿以实现逐滴冷凝的必要性。本文报道了在具有低接触角滞后（<3°）的光滑，固态，亲水表面（θa= 38°）上的稳定滴状凝结。我们表明，聚结液滴的纳米级至微米级至宏观级液滴尺寸（约100 nm至1 mm）的分布与疏水性表面上的经典分布非常吻合，并阐明了由润湿性控制的逐滴至薄膜过渡是介导的通过离开的液滴的键数。