Abstract
A nanostructured surface with diverse wettability which has the properties of superhydrophilicity, superhydrophobicity and distinguished wetting contrast is important to several key technologies. To meet these requirements, a facile and cost-effective approach via the electrochemical fabrication of a nano-sponge-like nickel oxyhydroxide/nickel hydroxide film on conductive glass followed by the application of external stimuli or chemical treatments is presented. The external stimuli of an environmental chamber and UV/ozone can dynamically and selectively control the aspect of wettability between hydrophobic and superhydrophilic in a short period. In addition, the aid of a chemical treatment with self-assembled non-fluorinated silane on annealed nickel hydroxide film can result in superhydrophobicity without degradation of optical transparency. The effectiveness of these achieved functions is demonstrated using transparent 2D microfluidic channels and direct selective electroplating.
This work was supported by the General Research Fund from the Research Grants Council of the HKSAR Government, People's Republic of China [grant number HKU 719512E].
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Notes on contributors
Ya-Huei Chang
Ms Ya-Huei Chang received her B.Sc. and M.Sc. degrees in Chemical Engineering from the National Tsing-Hua University, Taiwan in 2005 and 2007, respectively. She then worked on the synthesis and structural analysis of solar cells for four years in the Research and Development Centre, Tripod Corporation, Taiwan. Since then, she has been studying as a Ph.D. candidate under the tutelage of Dr Shien-Ping Feng at the University of Hong Kong. Her research interests focus on the controlled synthesis and catalytic applications of metal/metal hydroxide nanocrystals.
Shien-Ping Feng
Dr Shien-Ping Feng is an Assistant Professor in the Department of Mechanical Engineering at the University of Hong Kong. He received his Ph.D. degree in Chemical Engineering from the National Tsing-Hua University, Taiwan (2003–2008) and was a Postdoctoral Associate at the Massachusetts Institute of Technology (MIT), the USA (2009–2011) prior to his appointment at the University of Hong Kong. He was a Principal Engineer, Section Manager and Technical Manager at Taiwan Semiconductor Manufacturing Company (2001–2008). His research interests lie in the area of the thermal and electrochemical properties of nanostructured materials and their applications in energy conversion and storage.