Factors Affecting the Spontaneous Motion of Condensate Drops on Superhydrophobic Copper Surfaces

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• 作者：Jie Feng ; Zhaoqian Qin ; Shuhuai Yao
• 刊名：Langmuir
• 出版年：2012
• 出版时间：April 10, 2012
• 年：2012
• 卷：28
• 期：14
• 页码：6067-6075
• 全文大小：672K
• 年卷期：v.28,no.14(April 10, 2012)
• ISSN：1520-5827

文摘

The coalescence-induced condensate drop motion on some superhydrophobic surfaces (SHSs) has attracted increasing attention because of its potential applications in sustained dropwise condensation, water collection, anti-icing, and anticorrosion. However, an investigation of the mechanism of such self-propelled motion including the factors for designing such SHSs is still limited. In this article, we fabricated a series of superhydrophobic copper surfaces with nanoribbon structures using wet chemical oxidation followed by fluorization treatment. We then systematically studied the influence of surface roughness and the chemical properties of as-prepared surfaces on the spontaneous motion of condensate drops. We quantified the 鈥渇requency鈥?of the condensate drop motion based on microscopic sequential images and showed that the trend of this frequency varied with the nanoribbon structure and extent of fluorination. More obvious spontaneous condensate drop motion was observed on surfaces with a higher extent of fluorization and nanostructures possessing sufficiently narrow spacing and higher perpendicularity. We attribute this enhanced drop mobility to the stable Cassie state of condensate drops in the dynamic dropwise condensation process that is determined by the nanoscale morphology and local surface energy.