文章基本信息

标题：Superhydrophobicity enhancement through substrate flexibility
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作者：Thomas Vasileiou ; Julia Gerber ; Jana Prautzsch 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：47
页码：13307-13312
DOI：10.1073/pnas.1611631113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceFlexible materials are ubiquitous in everyday life and technology; however, their effect on wetting dynamics is not well understood. We explore the related physics and whether substrate flexibility can be made to work synergistically with surface microtexturing and nanotexturing to enhance superhydrophobicity. Remarkably, we show that, depending on substrate areal density, stiffness, and damping, a tunable collaborative effect of elasticity and superhydrophobicity can be realized. We identify the mechanism responsible for this enhancement with a simple collision model, and we propose design criteria for promoting this behavior. We exemplify the above discoveries, with materials ranging from man-made (thin steel or polymer sheets) to nature-made (butterfly wings). Inspired by manifestations in nature, microengineering and nanoengineering of synthetic materials to achieve superhydrophobicity has been the focus of much work. Generally, hydrophobicity is enhanced through the combined effects of surface texturing and chemistry; being durable, rigid materials are the norm. However, many natural and technical surfaces are flexible, and the resulting effect on hydrophobicity has been largely ignored. Here, we show that the rational tuning of flexibility can work synergistically with the surface microtexture or nanotexture to enhance liquid repellency performance, characterized by impalement and breakup resistance, contact time reduction, and restitution coefficient increase. Reduction in substrate areal density and stiffness imparts immediate acceleration and intrinsic responsiveness to impacting droplets ([~]350 x g), mitigating the collision and lowering the impalement probability by [~]60% without the need for active actuation. Furthermore, we exemplify the above discoveries with materials ranging from man-made (thin steel or polymer sheets) to nature-made (butterfly wings).
关键词：droplet impact ; superhydrophobicity ; flexible ; wetting transition ; biomimicry