Experimental and theoretical evaluation of wettability on micro/nano hierarchically engineered surfaces based on robust micro-post-arrayed- and highly ordered nano-rippled-structures

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• 作者：Dae-Ho Kim^a ; Yongsung Kim^b ; Sung-Hyun Hwang^c ; Yong-Seung Bang^c ; Chae-Ryong Cho^a ; ^d ; Yong-Kweon Kim^c ; ^{yongkkim@snu.ac.kr"" rel=""nofollow} ; Jong-Man Kim^a ; ^e ; ^{jongkim@pusan.ac.kr"" rel=""nofollow}
• 关键词：Highly self-ordered nano-rippled surface ; Micro-post arrays ; Micro/nano hierarchical surface ; Mechanical stability ; Structural regularity ; Hydrophobicity ; Superhydrophobic robustness
• 刊名：Applied Surface Science
• 出版年：2011
• 出版时间：15 August 2011
• 年：2011
• 卷：257
• 期：21
• 页码：8985-8992
• 全文大小：1781 K

文摘

This paper reports a simple approach for demonstrating a micro/nano hierarchical surface, ensuring both geometrical regularity and mechanical stability, for improving the hydrophobicity. The proposed dual-scale hierarchical surfaces were realized simply by combining the highly self-ordered ripple-like nano patterns with the robust micro-post arrays, based on the cost-effective nonlithographic chemical oxidation process and well-established microfabrication technologies. The wettability of the proposed nano-scale mono- and micro/nano dual-roughened surfaces was evaluated by measuring the apparent contact angles (ACAs), and analyzed theoretically with analytic models based on the Wenzel, Cassie, and combined wetting theories. Through experimental and theoretical observations, it was found that the proposed micro/nano hierarchical structures can improve the wetting property and the superhydrophobic robustness of high- and low-density micro-post arrayed surfaces, respectively.