A surface that can't be wetted.

Discussion in 'General Science' started by BR-549, Nov 28, 2014.

  1. BR-549

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  2. nsaspook

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  3. #12

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    Oh. From the title, I thought you meant, "modern Cell phones". Never mind.

    :D
     
  4. WBahn

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    But that wasn't the claim. The claim is that liquids would be repelled by it.

    It would be interesting to see how it behaved in the presence of a superfluid such as Helium.
     
  5. Wendy

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    It would probably climb up the side of such a container with even more vigor.
     
  6. nsaspook

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    The article header did say 'any liquid' but inside it said "The surface super-repelled all available liquids, including water, oils and many solvents, qualifying to be superomniphobic".

    The liquid-air interface is what's important for that repelling action. The liquid energy barrier of the surface of the liquid depends on the density change IRT air to form and without it you have nothing that acts to repel.
     
  7. sdowney717

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    So will it prevent marine bio fouling organisms. like slime and barnacles from growing on your boat?
     
  8. #12

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    That would be so good! Can't wait for somebody to hang a piece of this in the ocean for a few weeks.

    (I hope there is no liquid helium in the ocean :eek: )
     
    Last edited: Dec 17, 2014
  9. GopherT

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    Yes, but if you put those liquids in an inert atmosphere, they are no longer flaming and cannot damage the silica (glass) micro structures. The author did not say anything about ALL liquids in ALL atmospheres. Also, your flaming with pyrophoric compounds is like complaining that a hydrophobic substrate not flame proof - simply because the molecule catches fire non it's own,

    The only things that would etch these surfaces are Hydrofluoric acid (HF) or hot concentrated caustic (NaOH) or (KOH or similar). Even those will take some time to erode the microstructure so, in my opinion, it does repel HF and NaOH (for some time).
     
  10. GopherT

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    This is actually a bio-inspired technology based on the "self-cleaning" effect of the lotus leaf. Arrays of Tiny spikes create a hydrophobic surface. Water beads up and rolls off the leaf and carries dust and dirt with it as is rolls off. The effect does work for anti-fouling of ship hulls but, unfortunately, sea water carries all kinds of abrasive crap that erodes/polishes the texture off over time.

    I don't think the surface will ever be commercialized as it must be frown in a PVD or CVD or ALD process in a chip fabrication lab.


    http://en.m.wikipedia.org/wiki/Lotus_effect
     
  11. nsaspook

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    What do you think a little CIF3 would do to these surfaces? We once used the stuff to clean CVD chambers but the insurance company didn't like the liability.
     
  12. GopherT

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    I forgot about F2 and all of the surrogates of F2 like (ClF3). You would immediately have SiF4 vapor mixed with HCl and various mixtures of other Cl, Si, O and F containing species. But then again, unless compressed, F2 and ClF3 and SF4 are gases at room temperature and fall out of the author's scope of "Liquids". It would be interesting to see how long they would bead up on the surface if compressed into liquids.
     
  13. nsaspook

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    Video of someone having too much fun.


    Another in the family that's a liquid. H2FSbF6
     
    Last edited: Dec 19, 2014
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  14. sdowney717

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    Here is SLIPS, which repels water, not based on the Lotus leaf hair idea, this is a flat surface coating.
    http://www.gizmag.com/slippery-liquid-porous-surfaces-slips/22909/
    Article mentions some marine usage to prevent ice buildup is possible. Biofouling is all about a slime that first starts to grow on the hull, then barnacles, etc... come along and feel that slime and think this is a food surface to live on. So if it prevents proteins, maybe it could prevent slime from starting to grow.
    http://www.gizmag.com/coating-makes-glass-tough-self-cleaning-slippery/28604/

    Rustoleum Never Wet is not suitable for a boat, just not durable. I think it is a fad.
     
  15. BR-549

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    I wonder what effect this would have on the cavitation of a propeller?
     
  16. GopherT

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    I wouldn't wonder about it too long. There are other more important effects than surface energy.
    It is like thinking that you will increase your top speed in your car by waxing your side mirrors.
     
  17. wayneh

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