Iridescence and superhydrophobicity combined on one surface

January 21, 2012 by Lisa Zyga weblog
graphene oxide
Biomimetic graphene oxide with iridescence like a butterfly's wing and superhydrophobicity like a rose petal. Image credit: Wang, et al. ©2012 Chemistry - An Asian Journal

( -- Scientists have combined two properties on a single piece of graphene oxide that don’t usually go together: iridescence (resulting in a rainbow-hued appearance) and superhydrophobicity (causing low-contact water droplets to strongly adhere to the surface). The engineered surface could have applications in liquid transportation and analysis, and due to graphene’s good electronic properties, possibly even in future electronic devices.

The researchers, Jian-Nan Wang and coauthors from Jilin University in Changchun, China, achieved these properties by creating a microscopic texture on the graphene oxide’s surface. By shining two laser beams on the surface, they created an interference pattern that burned tiny grooves into the material. The surface immediately took on an iridescent appearance, shimmering like a butterfly’s wing. The scientists explained that the tiny grooves, which form highly ordered periodic structures, act as diffraction gratings that split white light into its various colored wavelengths.

The researchers discovered that the surface effects also caused the graphene oxide to exhibit highly adhesive superhydrophobicity. When they poured water on the surface, the water merged into nearly spherical droplets. Although the droplets are barely in contact with the graphene oxide, they adhere to the surface, not detaching even when the surface is held upside down. The researchers attributed this phenomenon to the surface’s microscopic unevenness and a decrease in surface energy caused during laser irradiation, which removes some hydrophilic oxygen groups.

The researchers predict that the combination of these two properties on one surface could have applications in microfluidic devices, where a superhydrophobic surface is useful for transporting small amounts of liquid in a controlled way. oxide might also be used as a biocompatible surface for growing cells, which requires controlled wetting.

The might be used for color-coding different states in microfluidic devices, as well as decorating for aesthetic purposes. Also, by altering the optical properties of graphene-based devices, it may open doors to new optical or electronic devices.

Explore further: Light-speed nanotech: Controlling the nature of graphene

More information: Jian-Nan Wang, et al. “Biomimetic Graphene Surfaces with Superhydrophobicity and Iridescence.” Chemistry - An Asian Journal. DOI: 10.1002/asia.201100882
via: Chemistry World

Related Stories

Light-speed nanotech: Controlling the nature of graphene

January 21, 2009

Researchers at Rensselaer Polytechnic Institute have discovered a new method for controlling the nature of graphene, bringing academia and industry potentially one step closer to realizing the mass production of graphene-based ...

A huge step toward mass production of graphene

March 10, 2010

Scientists have leaped over a major hurdle in efforts to begin commercial production of a form of carbon that could rival silicon in its potential for revolutionizing electronics devices ranging from supercomputers to cell ...

Damaging graphene to create a band gap

November 22, 2010

( -- "Graphene offers a lot of interesting potential applications for nanoelectronics," Florian Banhart tells, "but there is no band gap. This is a well-known problem. Without the band gap, switching ...

Graphite + water = the future of energy storage

July 15, 2011

A combination of two ordinary materials – graphite and water – could produce energy storage systems that perform on par with lithium ion batteries, but recharge in a matter of seconds and have an almost indefinite ...

Recommended for you

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...

Getting under the skin of a medieval mystery

November 23, 2015

A simple PVC eraser has helped an international team of scientists led by bioarchaeologists at the University of York to resolve the mystery surrounding the tissue-thin parchment used by medieval scribes to produce the first ...

Moonlighting molecules: Finding new uses for old enzymes

November 27, 2015

A collaboration between the University of Cambridge and MedImmune, the global biologics research and development arm of AstraZeneca, has led researchers to identify a potentially significant new application for a well-known ...


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jan 20, 2012
superhydrooptophobomicroiridofluidotransistors i try in wordfeud...
2 / 5 (4) Jan 20, 2012
I'd like to see this added to automotive paint to create a vehicle that sheds water instead of rusting away. I can also see a windshield coating that would afford privacy while shedding water, ice and possibly mud thrown up by passing vehicles.
not rated yet Jan 20, 2012
I'm rather more interested by the "adhesive yet hydrophobic" qualities of this substance than its iridescence, frankly. They note that hydrophilic oxygen groups are removed (and, presumably, other polar groups are also absent), yet the water droplets still somehow adhere? Van der Waals attraction, maybe?
5 / 5 (3) Jan 20, 2012
After doing a bit of reading, it would seem that van der waals forces may me the culprit for adhesion. Gecko pads are adhesive and hydrophobic and an aluminum oxide type material with a pillar type surface (created by researchers studying the gecko pads) showed the same properties. So it's probably not a big stretch to infer the same type of mechanic is involved on this graphenes surface.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.