Humidity Responsive Asymmetric Free-Standing Multilayered Film

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• 作者：Liyan Shen ; Jinhong Fu ; Ke Fu ; Catherine Picart ; Jian Ji
• 刊名：Langmuir
• 出版年：2010
• 出版时间：November 16, 2010
• 年：2010
• 卷：26
• 期：22
• 页码：16634-16637
• 全文大小：798K
• 年卷期：v.26,no.22(November 16, 2010)
• ISSN：1520-5827

文摘

A humido-responsive free-standing film has been created using layer-by-layer assembly technique. Polyethylenimine (PEI) at high pH was assembled with poly(acrylic acid) (PAA) at low pH on a Teflon substrate to yield a micro-nanostructured surface that can be made superhydrophobic after being coated with a low surface energy compound. The resulting asymmetric free-standing film with one surface being superhydrophobic while the other is hydrophilic after detachment from the substrate can undergo reversible bending/unbending shape transitions when the environmental humidity is changed. The bending/unbending movement of the free-standing film can be ascribed to the different responses of these two surfaces to humidity.