Issue 20, 2017

Water-repellent hydrophilic nanogrooves

Abstract

The wetting behavior of a nanodrop atop a nanogroove on a smooth or a rough surface is explored by many-body dissipative particle dynamics and Surface Evolver. The nanogroove possesses the same contact angle (θY) as that of the surface. Depending on whether the groove is initially wetted or not, two critical contact angles Image ID:c7cp01409k-t1.gif beyond which the groove cannot be wetted are determined. Three regimes are identified: (i) as θYθcY, the groove is always wetted; (ii) as Image ID:c7cp01409k-t2.gif, both impregnated and unwetted states can be observed; (iii) as Image ID:c7cp01409k-t3.gif, the groove cannot be impregnated. As the drop volume is increased, both θcY and Image ID:c7cp01409k-t4.gif decrease but become insensitive to the volume eventually. Surface roughness tends to hamper the impregnation of grooves by liquid. Compared to a smooth surface, both critical contact angles of a rough surface with regular shallow pits are smaller. As a result, a large drop is unable to wet the groove with a rough surface even when the surface becomes slightly hydrophilic. When the surface structure within the groove is modified from shallow pits to straight trenches, the critical contact angle is further reduced. Our simulation outcomes show that the surface structure within the groove is crucial for liquid imbibition and it is possible to fabricate hydrophilic cavities that can prevent impregnation, without resorting to chemical modification processes.

Graphical abstract: Water-repellent hydrophilic nanogrooves

Article information

Article type
Paper
Submitted
04 Mar 2017
Accepted
19 Apr 2017
First published
27 Apr 2017

Phys. Chem. Chem. Phys., 2017,19, 13022-13029

Water-repellent hydrophilic nanogrooves

Y. Weng, I. Hsieh, H. Tsao and Y. Sheng, Phys. Chem. Chem. Phys., 2017, 19, 13022 DOI: 10.1039/C7CP01409K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements