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Science

"Superomniphobic" Nanoscale Coating Repels Almost Any Liquid 104

Posted by samzenpus from the keeping-it-dry dept.
cylonlover writes "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."
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"Superomniphobic" Nanoscale Coating Repels Almost Any Liquid More

"Superomniphobic" Nanoscale Coating Repels Almost Any Liquid

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  • Heck, if we all wear slippery clothing, I guess we don't need the slip and slide anymore. We can just run and jump and hit the ground sliding off into the sunset.

    Oh! What about shoe soles? To heck with rolerblades. We can just scoot around on the soles of our shoes!

    Oh my God I'm having an idea-anurism!!
    • Crap I forgot....it only repels liquid. Not concrete. Rats.

    • Re: (Score:2)

      by Macgrrl ( 762836 )

      What happens if two people wearing this kind of treated fabric try to hug each other - would they bounce off?

      I would potentially mean the end of inadvertent wet T-shirt competitions. ;P

      • Re: (Score:2)

        by Guignol ( 159087 )
        Oh, no you are right ! I'm afraid this could be the end of wet t-shirt competitions (anaquamamaphiliaphobia)
        I have to add this to my fear of heights (vertigo), spiders (arachnophobia), fears (phobiphobia), agoraphobia, claustrophobia, ...
        In fact I was just missing this one last fear to have them all, I am now superomniphobic
        I guess this is how they made their "research", mental torture of the subjects, this is disgusting

  • You can turn your clothes into a computer [phys.org]

  • It's been tried on 'postage stamp' bits of cloth. No mention of stability, durability, flammability or other useful properties.

    'Superomniphobic', eh? Sounds like something out of a tacky Disney movie.

    • "'Superomniphobic', eh? Sounds like something out of a tacky Disney movie."

      I know a few people who are also afraid of everything.

    • 'Superomniphobic', eh? Sounds like something out of a tacky Disney movie.

      I can hear Mary Poppins saying: "Superomniphobic? Almost, but not quite there." :-)

  • Old News ... (Score:5, Funny)

    by SpockLogic ( 1256972 ) on Thursday January 17, 2013 @07:34PM (#42621891)

    Obi-Wan Kenobi foretold this in 1951 http://www.imdb.com/title/tt0044876/ [imdb.com]

  • I repel most liquids too (Score:5, Funny)

    by FeatherBoa ( 469218 ) on Thursday January 17, 2013 @07:35PM (#42621899)

    I repel most liquids too, although beer and coffee keep slipping though my formidable defences.

    • The hardware should be fluid resistant, but your resistance is futile. Don't tell me you haven't learned the Osmosis trick. It saves a lot of drinking time just bathing in it, and since you're not going to put it in your mouth you can even eliminate most trips to the toilet.

      Ahhh, Beeffee.

      • Re: (Score:2)

        by sFurbo ( 1361249 )
        The skin is far to good a barrier for osmosis to work with alcohol and (I think) caffeine. It works with nicotine, which is why nicotine patches are so easy to make, and if you dissolve thing in DMSO first, though.

  • What uses come to mind? (Score:5, Interesting)

    by Commontwist ( 2452418 ) on Thursday January 17, 2013 @07:36PM (#42621903)

    I know that lawn mowers, should you leave gas in them for a while, will gain a 'coating' that gums up the fuel needle in the carburetor. Cleaning out the carb is a true pain and costs a lot to get a mechanic to clean/replace. Would this kind of coating over that small and delicate part help ease/eliminate sticking?

    • Re:What uses come to mind? (Score:4, Insightful)

      by oodaloop ( 1229816 ) on Thursday January 17, 2013 @07:45PM (#42621963)
      Motorcycle visors come to mind. And, you know, all those other ones mentioned in TFS. And white suits.

      • Re: (Score:2)

        by rnturn ( 11092 )

        "And white suits."

        Ah... someone beat me to it. (Great old movie.)

      • Motorcycle visors come to mind. And, you know, all those other ones mentioned in TFS. And white suits.

        As to motorcycle visors, super-hydrophilic may be the way to go. When a droplet hits the surface it's instantly spread in an even layer over the whole area, no beading.

    • Any place we currently use a lubricant would find this useful, as coating the parts in this prior to lubrication *should* decrease wear through a decrease in friction. Theoretically, this surface should also wear extremely well provided it's always coated in a lubricant.

      Two layers of this with an oil layer in between would be a performance and durability boost for most things that have moving parts.

      Now we just need to decrease production cost/increase production and discover how it stands up to *other* for

      • Repelling fluids does not imply low friction or even durability, for example water beading up on soft silicon rubber. Plus I would think you would want an oil attracting surface for a friction surface.

        • Not necessarily. Just think about it as of a ball bearing made out of oil droplets...

          • Not necessarily. Just think about it as of a ball bearing made out of oil droplets...

            That just squirt out the side of the bearing? Oil and grease need to stay in the interface to actually work.

    • Or, and IANAL (I am not a lawnmower-mechanic), you could stop leaving your lawnmower with gas in it for extended periods. Step one: disconnect gas line and drain gas into external vessel. Step two: start lawnmower and let run until it stops on its own accord. Or, even easier if less environmentally friendly, at the end of the lawnmowing season let lawnmower run until it stops of its own accord. No science required.

      • Oh, I agree. Sadly, more than a few people don't bother to spend more than one minute reading manuals or checking for possible maintenance issues. Add ethanol and higher efficiencies (making engines more sensitive to gas issues) to the mix and it just gets worse. Preferably they should follow your advice but ways to reduce the problem couldn't hurt.

    • Protip: To prevent shellacking just dump some fuel stabilizer in it before you put it away for the winter. Good advice for all small engines.

    • Re: (Score:1)

      by Anonymous Coward

      There are people out there who actually pay a mechanic to fix their goddamn lawnmower engine? Do you really find them to be so complicated?

      • One data point: I've got a Toro walk-behind that's over 10 years old now. I've never once emptied the gas tank for the winter, never once done an internal cleaning, and it starts right up like a charm every spring.
        Heck, a poor young child saw it smoking a bit once and thought it was due to lack of oil, tossed in a quart or so. The engine started kicking oil out the air intake things were so bad. I dumped the oil, cleaned the air filter, and it ran like a charm.
        So my point is that this "gummed up by gas"

    • Re: (Score:3)

      by tlhIngan ( 30335 )

      I know that lawn mowers, should you leave gas in them for a while, will gain a 'coating' that gums up the fuel needle in the carburetor. Cleaning out the carb is a true pain and costs a lot to get a mechanic to clean/replace. Would this kind of coating over that small and delicate part help ease/eliminate sticking?

      Gasoline is volatile. It will evaporate quite rapidly at room temperature.

      However, the gas you get from the pump has a bunch of additives and other stuff added to it - detergents to keep your engi

  • Yet another miracle nano-coating (Score:5, Insightful)

    by Spy Handler ( 822350 ) on Thursday January 17, 2013 @07:37PM (#42621911) Homepage Journal

    Every x months for the past 5 years I hear about some new super-coating that repels dirt, water, oil etc.. Every time I'm like, "cool, when will it come standard on new cars?" I hate having to wash my car every few days (it's parked outside) or it starts looking like crap.

    I suppose when I get a flying car, that's when I'll finally see this miracle coating in action.

    • Re:Yet another miracle nano-coating (Score:5, Insightful)

      by norpy ( 1277318 ) on Thursday January 17, 2013 @07:44PM (#42621953)

      Hopefully this clears things up for you:

      http://xkcd.com/678/ [xkcd.com]

    • Re: (Score:2)

      by Trogre ( 513942 )

      We have about two and a half years to wait until we get both flying cars and dust repellent paper.

    • Re:Yet another miracle nano-coating (Score:5, Informative)

      by Anonymous Coward on Thursday January 17, 2013 @08:28PM (#42622235)

      Every x months for the past 5 years I hear about some new super-coating that repels dirt, water, oil etc.. Every time I'm like, "cool, when will it come standard on new cars?" I hate having to wash my car every few days (it's parked outside) or it starts looking like crap.

      I suppose when I get a flying car, that's when I'll finally see this miracle coating in action.

      Posting anonymously because of a personal connection to research some of these materials, but I think it's worth it to quickly clear up a few uncertainties I see in the comments already posted:

      1) The reason you don't see this stuff all over is that these materials are expensive and usually not durable. Nanoscale patterns can be created through a variety of approaches, some of which are a bit more complicated but can repair or recreate their surface patterns after abrasion. As you might expect, the materials that can recreate their surface patterns tend to be on the more expensive end of the scale.

      2) The past 5 years have seen major progress in *phobic materials. We're getting closer to cost effective, more durability, and even better phobicity, but we're still not there.

      3) Superhydrophobic isn't the same as omniphobic. Generally surfaces will either have a high contact angle with water OR with nonpolar liquids. Superhydrophobic means the contact between a droplet of water and the material will be extremely small. Omniphobic means the surface repels both polar and nonpolar liquids.

      4) Nanoscale patterning of a surface can also lead to superhydrophilicity, the opposite of superhydrophobicity. The mechanism for this isn't fully understood.

    • No idea if this is the case or not, but maybe they get killed in the environmental impact stage.

  • Democrats? (Score:4, Funny)

    by dhalsim2 ( 626618 ) on Thursday January 17, 2013 @07:39PM (#42621923)

    I know a few Democrats that were superromneyphobic.

  • We're 60 percent water. Maybe it will repel us.

  • I wonder how it compares with that 'NeverWet [neverwet.com]' or Rain X stuff. Apparently, the contact angle of the former for a drop of water is around 160-175 degrees (close to perfect 180), but may have problems with durability (and is pervious to solvents, detergents, soap and high pressure water). The latter - Rain X - is already in commercial use, namely for car windscreens, but only has a contact angle of 110 degrees, so isn't superhydrophobic.

    I refer to my earlier post which gave these stats:
    http://hardware.sla [slashdot.org]

    • I wonder how it compares with that ' NeverWet [neverwet.com]' or Rain X stuff. Apparently, the contact angle of the former for a drop of water is around 160-175 degrees (close to perfect 180), but may have problems with durability (and is pervious to solvents, detergents, soap and high pressure water). The latter - Rain X - is already in commercial use, namely for car windscreens, but only has a contact angle of 110 degrees, so isn't superhydrophobic.

      I refer to my earlier post which gave these stats:

      http://hardware.slashdot.org/comments.pl?sid=2813771&cid=39813937 [slashdot.org]

      I can tell you right now that buying Rain-X wiper blades and their spray-on shit was one of the worst decisions of my life. No better than stock blades and generic glass cleaner.

      • I don't know about wipers but rain x washer fluid is noticeable.

        during heavy rain you can watch the bead and run off your windshield.

      • At one point, Rain X was glorious. I could be in the wash of a tractor trailer in a heavy rain and barely need my wipers.

        But then, something happened. The Rain X started making my windshield kind of blurry. I'm pretty sure it was the Rain X. I spent a lot of effort scrubbing that windshield afterwards to get the Rain X off. ISTR that after several months, it went back to normal, and I was stuck with regularly replacing wiper blades and keeping the windshield clean. I think it was because it got old and bec

    • RainX and this stuff seem to be made of the same starting material, i.e. polydimethylsiloxane.

      The difference is the surface morphology of the superhydrophobic material increases the contact angle to 180 degrees.

    • Re:Comparison to Neverwet (Score:5, Informative)

      by slew ( 2918 ) on Thursday January 17, 2013 @08:17PM (#42622171)

      All this superhydrophobic stuff is mostly just silicone.

      The main difference is how it's applied and what type of structure it forms. As I understand it RainX is mostly just a simple silicone coating where the idea is to just smooth out the windshield (in the theory that on a completely smooth surface, water is more likely to bead than whet). NeverWet is a silicone nano-particles suspended in a spray/solvent. When the solvent evaporates, it makes a somewhat uniform coating of nano-particles of silicone.

      Apparently in this technique, they apply silicone with electrospinning [wikipedia.org] instead of run-of-the-mill spray-n-dry techniques. The main difference is that with electrospinning it is accomplished w/o w/o solvents and the result can be made into a very uniform nano-structure. There's also no solvent to ruin whatever you need to apply it to. Of course figuring out the right technique to create a specific nano-structure that works as you intend it isn't an accomplishment to be sneezed at (not that it would stick anyhow)...

      • Re:Comparison to Neverwet (Score:4, Informative)

        by reverseengineer ( 580922 ) on Thursday January 17, 2013 @11:02PM (#42622935)

        This coating is actually not just silicone, but a blend of silicone and " liquid-resisting nanoscale cubes developed by the Air Force that contain carbon, fluorine, silicon and oxygen," which is apparently supposed to be layman's terms for fluorodecyl polyhedral oligomeric silsequioxane (POSS). Those are cubic networks of silica that have a fluorocarbon chain at each vertex, sort of a three-dimensional Teflon. The very low chemical reactivity plus the nanoscale roughness of the surface causes the lotus effect. [wikipedia.org] The mixture with silicone helps the POSS adhere to materials, though they state in their paper that the POSS preferentially segregates to the surface and is responsible for the coating's properties:

        "A wide range of organic chemicals including toluene and chloroform, which readily wet/swell cross-linked PDMS, are also easily repelled. Even when our surfaces are immersed in a liquid bath of PDMS (Mn = 800 Da, lv = 19.8 mN/m), a plastron (air pockets) layer that is indicative of a robust Cassie–Baxter state is formed. The plastron layer was stable and remained unchanged even upon extended exposure to un-cross-linked PDMS. Note that PDMS is a major constituent of the electrospun beads. The observation of a stable plastron layer even when the surface is submerged under PDMS is extremely unique and indicates that the surface does not reconfigure, even when exposed to an enthalpically favorable solvent."

  • For extra smooth slip n' slide? Don't want it on the inside, the thing will slip right off. Or maybe just put the coating on the outside and also just the inside tip.

    • Re: (Score:3)

      by JazzXP ( 770338 )
      You know this is /. right? ;-)

      • Re: (Score:2, Informative)

        by Khyber ( 864651 )

        I work in a porno shop and probably get laid way more than the entirety of the /. population combined.

        • Re: (Score:3)

          by hey! ( 33014 )

          I work in a porno shop and probably get laid way more than the entirety of the /. population combined.

          I can well believe both your assertions, but fail to see how they are connected.

          • Porno shops are notorious gay cruise spots.

            I know a lady who manages a chain of them. She got into a world of hurt for going on record, refused to hire a straight man because he 'wasn't the gay boy they were looking for'.

            When she drinks, she likes to vent about the perverts...TMI...ears burn.

  • It's my understanding that this kind of surface erodes relatively quickly, and thus rapidly loses its liquid repelling properties as it is handled or touched by other things that are solid in far too brief a time to be practical for anything but a temporary coating.

    • If the object is not often moving and rubbing against other objects (mmmm... rubbing), then the coating need not be temporary.
      Dust-proof museum art.
      Spider-proof ceilings (seriously, this is all I can think of). I guess it's not very useful that way.

      The insides of windows?

      Basically any object which is furniture.

      • Re: (Score:2)

        by mark-t ( 151149 )

        Inside of windows would be impractical for most purposes because it could still easily get touched by people's hands, eventually wearing off.

        And this nanotech is not trivial to make, so it's far too expensive to simply have it as a temporary coating.

        The underlying concept is a good one... but they need to figure out a way to make it durable enough to cope with real-world handling conditions, or else it's useless for anything that has any possibility of being touched by anything solid.

  • John Gotti is now "The Superomniphobic Don".

  • Wouldn't coatings with complex surface geometry like that have issues with friction wearing them flat? I could see that not being a big deal on rigid surfaces that don't really contact anything, but other products, like clothing seem like they would be especially troublesome. Even on things like windshields seem like they would pose a problem with the wiper blades constantly rubbing the surface down.

  • ... Wicked Witches around the world look forward to this as a breakthrough technology.

    Quoting one spokeswiccan, "I'll get you, my pretty, and your little dog, too!"

  • It seems if it were a paint it might help. Once. The second coat could be problematic.

  • I hope this can be used to improve athletic clothing that's supposed to whisk away sweat. Nothing I work out in seems to "work".

  • and subsequently banned in controversial Olympic swimsuits

  • wears off from flexing. Right now you can repel HCL and H2SO4 with NanoTex stain resistant clothing. My last lab coat I needed or the lab was treated with this product already from the manufacturer. Because All acids are mostly water, so repel the water instead. IF you are spilling concentrated acid on yourself, you need to be kicked in the nuts for being a danger in the lab.

  • we'll have hyperomniphopic, then turbo-omniphopic, then überomniphopic, etc. and all the while we'll still see few, if any, real world applications. These nanoscale surfaces are just too fragile. They'd probably work well for disposable products (although that raises the issue of how well garbage breaks down when it can't even get wet). For some of the most useful applications, the coating would have to be re-applied regularly. That raises the issue of safety of such products. I can only imagine what k
  • You mean Republican?
  • I've never been able to figure out how a coating can "repel" a neutrally-charged molecule (like water, say). Seems like the best you can do is just be as non-polar as possible so that you don't cause any static polar or induced Van Der Waal's attractions, such that the liquid is attracted to *itself* much more than to your coating.

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