Evaporation of Water Droplets on 鈥淟ock-and-Key鈥?Structures with Nanoscale Features

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• 作者：Xiaolong Zhu ; Chi Zhang ; Xiaohan Liu ; Ole Hansen ; Sanshui Xiao ; N. A. Mortensen ; Jian Zi
• 刊名：Langmuir
• 出版年：2012
• 出版时间：June 26, 2012
• 年：2012
• 卷：28
• 期：25
• 页码：9201-9205
• 全文大小：331K
• 年卷期：v.28,no.25(June 26, 2012)
• ISSN：1520-5827

文摘

Highly ordered poly(dimethylsiloxane) microbowl arrays (MBAs) and microcap arrays (MCAs) with 鈥渓ock-and-key鈥?properties are successfully fabricated by self-assembly and electrochemical deposition. The wetting properties and evaporation dynamics of water droplets for both cases have been investigated. For the MBAs case, the wetting radius of the droplets remains unchanged until the portion of the droplet completely dries out at the end of the evaporation process. The pinning state extends for more than 99.5% of the total evaporation time, and the pinning鈥搒hrinking transition is essentially prevented whereas in the case of the MCAs the contact radius exhibits distinct stages during evaporation and the contact line retreats significantly in the middle of the evaporation process. We explain the phenomenon by a qualitative energy balance argument based on the different shrinkage types of the nanoscale-folded contact line.