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"Superomniphobic" nanoscale coating repels almost any liquid

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January 16, 2013

Most liquids literally bounce off surfaces treated with a 'superomniphobic' coating develo...

Most liquids literally bounce off surfaces treated with a 'superomniphobic' coating developed at the University of Michigan

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A team of engineering researchers at the University of Michigan has developed a nanoscale coating that causes almost all liquids to bounce off surfaces treated with it. Creating a surface structure that is least 95 percent air, the new "superomniphobic" coating is claimed to repel the broadest range of liquids of any material in its class, opening up the possibility of super stain-resistant clothing, drag-reducing waterproof paints for ship hulls, breathable garments that provide protection from harmful chemicals, and touchscreens resistant to fingerprint smudges.

Made up of a mixture of rubbery plastic particles of “polydimethylsiloxane” (PDMS) and liquid-resisting nanoscale cubes containing carbon, fluorine, silicon and oxygen, the coating is applied to surfaces using a technique known as electrospinning, which uses an electric charge to create fine solid particles from a liquid solution. These solid particles that hug the pore structure of the surface it is applied to and create a finer web within those pores.

Similar to the way water droplets are suspended by air pockets created between tiny hairs on the surface of lotus leaves, the coating creates a structure that is 95 to 99 percent air pockets. This means that liquids coming into contact with the coating barely touch a solid surface, thereby reducing the intermolecular Van der Waals forces that normally draw two states of matter together.

Coffee running off a piece of fabric treated with the new nanoscale coating (Photo: Joseph...

"Normally, when the two materials get close, they imbue a small positive or negative charge on each other, and as soon as the liquid comes in contact with the solid surface it will start to spread," said Anish Tuteja, assistant professor of materials science and engineering, chemical engineering and macromolecular science and engineering. "We've drastically reduced the interaction between the surface and the droplet."

With so little surface are with which to interact, the droplets interact only with molecules of themselves. This means they stay intact, retaining a spherical shape and literally bounce off the treated surface.

So far, Tuteja and his colleagues have applied the coating to small tiles of screen and postage-stamp sized swatches of fabric. After testing more than 100 liquids, the researchers found only two that were able to penetrate the coating – both chlorofluorocarbons (CFCs) that are used as refrigerants in air conditioners and refrigerators.

Already proven effective on coffee, soy sauce, vegetable oil, gasoline, and various alcohols, the coating can also repel acids that could burn skin, such as hydrochloric and sulfuric acids. Tuteja says the coating is also the first demonstrated to repel low surface tension non-Newtonian liquids. These are liquids, such as shampoos, custards, blood, paints, clays and printer inks, that change their viscosity depending on the amount of force applied to them.

The team’s paper is published in the Journal of the American Chemical Society.

Tuteja demonstrates the nanoscale coating in the video below.

Source: University of Michigan

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag.   All articles by Darren Quick
12 Comments

i wish there was more, a lot more. i do have questions what carbon R we talking about? what results could be expected in utilizing this with graphene 1 atom thick or ceramic membranes? i think this may go way beyond initial intentions and i certainly hope so.

slayerwulfe
16th January, 2013 @ 08:24 pm PST

how durable could this be?

how much would it cost?

wle

wle
17th January, 2013 @ 08:18 am PST

Just saw something like this at Costco of all places. They were selling toilet bowl plungers coated with some sort of nano particle so that when you pull the plunger out of the toilet, it comes out dry, so no mess on the floor, and because bacteria is present in the water, much less bacteria ends up living on the plunger. Pretty neat, I instantly thought of a hundred other applications, boots, coats, umbrellas, cups could be awesome because it should improve the insulative properties and you'll always get that last sip!

Tim Gesner
17th January, 2013 @ 08:52 am PST

Isn't there gathering body of research showing the dangers of some nano particles getting into our bodies?

Jan Angevine
17th January, 2013 @ 09:19 am PST

In the mid seventies I recall reading a Business Week article bragging about the merits of super hydrogenated fats to resist oxidation. This would herald an era of progressively larger scale manufactured foods that would have long shelf lives that would not go "stale" from oxidation reduction of the baked or fried fats therein.

I immediately decided to make a lifelong practice of limiting my consumption of such foods since a fat component that would not oxidize on the shelf also will not be digested normally. Over the last forty years research has progressively, and now, conclusively shown that my concern was correct.

Fire resistant compounds used on lots of fabrics now can be readily measured everywhere, including the Arctic, Ant-Arctic and in the bloodstreams of pretty much every living thing.

So, what happens when some kind of compound that resists all liquids, obviously including liquids in us and in all the food we and all other animals eat winds up spattered across the world?

StWils
17th January, 2013 @ 11:02 am PST

@StWils - what happens, is that graffiti doesn't stick anymore, and the world goes back to being drab-gray everywhere.

christopher
17th January, 2013 @ 05:38 pm PST

A coating to make your car stay clean and even be more aero dynamic, thats pretty cool. I'm sure the company will/should work out all the kinks before mass production.

Gargamoth
17th January, 2013 @ 06:32 pm PST

Wonderful idea! This would revolutionize life. Think of the possibilities! Coated windows that repel water and dirt, coated sinks/toilets/tubs, windshields, building siding, car finishes, window screens...

So many ideas....

flink
18th January, 2013 @ 06:00 am PST

What comes to mind is coating the inside of pipes & tubes with the intended result being the prevention of plaque build-up & eventual clogging & bacterial growth & colony formation. Whether or not this is a good plan hinges on the answer to some of the other "posters" concerns, specifically those of surface coating adhesion integrity & potential toxicity.

SciGuy3822
18th January, 2013 @ 07:06 am PST

To get a more permanent and commercial product, go see the stuff from C-Voltaics. They seem to have done this on a commercial scale while the rest are still doing a PR academic job -

BTW: UMish is great school without any doubt, lets see what comes up next

DaedalusTx
21st January, 2013 @ 10:19 pm PST

Why not use this to protect the inside of large arteries?

Alex Aricci
22nd January, 2013 @ 05:27 am PST

Would this keep the sailboat's from geting barnacles forming on them? It shood make them run faster and on less fuel.

Wade Randall
14th May, 2013 @ 07:00 am PDT
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