Multiscale Effect of Hierarchical Self-Assembled Nanostructures on Superhydrophobic Surface

详细信息    查看全文

• 作者：Luca Passoni ; Giacomo Bonvini ; Alessandro Luzio ; Anna Facibeni ; Carlo E. Bottani ; Fabio Di Fonzo
• 刊名：Langmuir
• 出版年：2014
• 出版时间：November 18, 2014
• 年：2014
• 卷：30
• 期：45
• 页码：13581-13587
• 全文大小：554K
• ISSN：1520-5827

文摘

In this work, we describe self-assembled surfaces with a peculiar multiscale organization, from the nanoscale to the microscale, exhibiting the Cassie鈥揃axter wetting regime with extremely low water adhesion: floating drops regime with roll-off angles < 5掳. These surfaces comprise bundles of hierarchical, quasi-one-dimensional (1D) TiO₂ nanostructures functionalized with a fluorinated molecule (PFNA). While the hierarchical nanostructures are the result of a gas-phase self-assembly process, their bundles are the result of the capillary forces acting between them when the PFNA solvent evaporates. Nanometric features are found to influence the hydrophobic behavior of the surface, which is enhanced by the micrometric structures up to the achievement of the superhydrophobic Cassie鈥揃axter state (contact angle (CA) 鈮?150掳). Thanks to their high total and diffuse transmittance and their self-cleaning properties, these surfaces could be interesting for several applications such as smart windows and photovoltaics where light management and surface cleanliness play a crucial role. Moreover, the multiscale analysis performed in this work contributes to the understanding of the basic mechanisms behind extreme wetting behaviors.