Superhydrophobicity and Superhydrophilicity of Regular Nanopatterns

Division of Electronics and Electrical Engineering, University of Glasgow, Glasgow, Scotland, United Kingdom
Nano Letters (Impact Factor: 13.59). 11/2005; 5(10):2097-103. DOI: 10.1021/nl051435t
Source: OAI

ABSTRACT The hydrophilicity, hydrophobicity, and sliding behavior of water droplets on nanoasperities of controlled dimensions were investigated experimentally. We show that the "hemi-wicking" theory for hydrophilic SiO(2) samples successfully predicts the experimental advancing angles and that the same patterns, after silanization, become superhydrophobic in agreement with the Cassie-Baxter and Wenzel theories. Our model topographies have the same dimensional scale of some naturally occurring structures that exhibit similar wetting properties. Our results confirm that a forest of hydrophilic/hydrophobic slender pillars is the most effective superwettable/water-repellent configuration. It is shown that the shape and curvature of the edges of the asperities play an important role in determining the advancing angles.

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Available from: Elena Martines, Sep 26, 2015
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    • "Topographical features have been studied at the micro-and nano-scale. However, investigating cell response to topography alone is complicated, because the wettability of the surface is variable with topographical changes [31]. Despite this difficulty, there are some results that suggest an association of cell response to feature pattern [32]. "
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    ABSTRACT: Surface modification technology has made significant advances in recent years towards the miniaturization and organization of traditional cell culture systems. However, the capability of directing transfected cells and neuronal connections to probe small structures such as spines is still under development. In the current work, interactions of different micropatterned substrates with HEK 293, CF10 cell lines, and primary neuronal cultures are evaluated. Using conventional and confocal fluorescence microscopies, several morphological and behavioral aspects of all three cell types were investigated. The immortalized cell lines were able to attach to the substrate and interact with neighboring cells. Similarly, cortical neurons formed connections guided by the micropatterns. Transfection of HEK 293 or CF10 cell lines with specific members of the G protein-coupled receptor family did not alter the behavior of these cells in the micropatterns. On the other hand, neuronal projections were efficiently isolated by the patterns, simplifying the localization of spines with nano-scale resolution probed by atomic force microscopy. This work presents a valuable approach to isolate cells or to constrain important cell structures to grow along a desired pattern, thus facilitating advanced biological studies.
    Biomaterials 10/2013; 34(38). DOI:10.1016/j.biomaterials.2013.09.070 · 8.56 Impact Factor
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    • "Several studies have proved that a correlation exists between the existence of a two-part surface structure and the super-hydrophobic behaviour. On the other hand, it has been shown that examples in nature exist, which exhibit one-part surface structures in the nanometer range with excellent super-hydrophobic behaviour [4] [5]. "
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