Materials

Self-healing waterproof coating stays dry for the long term

Self-healing waterproof coatin...
A  new superhydrophobic, self-healing material is said to be hundreds of times more durable than comparable water-repellent coatings
A  new superhydrophobic, self-healing material is said to be hundreds of times more durable than comparable water-repellent coatings
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A  new superhydrophobic, self-healing material is subjected to an erosion test
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A  new superhydrophobic, self-healing material is subjected to an erosion test
A  new superhydrophobic, self-healing material self-heals itself, even when exposed to flame
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A  new superhydrophobic, self-healing material self-heals itself, even when exposed to flame
A  new superhydrophobic, self-healing material is said to be hundreds of times more durable than comparable water-repellent coatings
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A  new superhydrophobic, self-healing material is said to be hundreds of times more durable than comparable water-repellent coatings
A  new superhydrophobic, self-healing material is said to be hundreds of times more durable than comparable water-repellent coatings
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A  new superhydrophobic, self-healing material is said to be hundreds of times more durable than comparable water-repellent coatings

By the end of 2017 we could start to see a new class of waterproof products that stay hydrophobic for the long haul. That's thanks to a breakthrough by University of Michigan researchers in creating a water-repellent spray-on coating they claim is hundreds of times more durable than similar substances. Even when the coating is damaged, it can heal itself over and over again.

The coating is actually a combination of materials called "fluorinated polyurethane elastomer" mixed with a water-repellent molecule known as "F-POSS." The researchers say that what sets their sprayable, rubbery coating apart from numerous similar products that have come out over the years (Ultra-Ever Dry comes to mind) is its next-level durability.

"Thousands of superhydrophobic surfaces have been looked at over the past twenty or thirty years, but nobody has been able to figure out how to systematically design one that's durable," said Anish Tuteja, an associate professor of materials science and engineering. "I think that's what we've really accomplished here, and it's going to open the door for other researchers to create cheaper, perhaps even better superhydrophobic coatings."

The substance is so tough that it could waterproof surfaces that current treatments typically struggle to perform on: things like cars, clothes, rooftops and even ship hulls, which could lead to lower resistance in the water resulting in better fuel efficiency for ubiquitous worldwide cargo shipments.

In addition to its longevity and toughness, the team says the coating can also self-heal itself hundreds of times when damaged. It can restore its water resistance "even after being abraded, scratched, burned, plasma-cleaned, flattened, sonicated and chemically attacked," the researchers wrote in a paper recently published in ACS Applied Materials & Interfaces.

Engineering a durable, hydrophobic, and self-healing coating

Even if molecules of the coating are scraped away from the surface, other molecules will migrate to fill in the gaps and heal the integrity of the hydrophobic surface.

One key to the new coating's impressive water aversion is basically a tweak to the geometry of the hydrophobic surface. Most water-resistant coatings employ microscopic pillars that create air pockets below water droplets. This gives them nowhere to rest and causes them to roll off. But this structure is also fragile. The researchers made their surface slightly pliable so that it can bend but not break in the face of pressure, thereby lasting longer.

A  new superhydrophobic, self-healing material self-heals itself, even when exposed to flame
A  new superhydrophobic, self-healing material self-heals itself, even when exposed to flame

Another team in Australia has also attempted to address this fragility by developing a new coating made from a combination of plastics; another models itself on the lotus leaf. Neither of those make the same claims of self-healing properties that help set this new approach apart.

The breakthrough is going to be brought to market by a new company founded by Tuteja called HygraTek, with the help of the University of Michigan. Tuteja is hopeful spray-on coatings and water-repellent fabrics could be available by the end of the year.

Source: University of Michigan

4 comments
zr2s10
This is awesome, and I hope it's not insanely expensive. I have lots of uses for this in my work, and I'm sure I can get my company to pay for it if proves out. But I also have lots of personal uses for it, so I hope it is as durable as they say. It would make my SxS a lot easier to clean off. And I hope that it's resistant to salt water, because this would actually make a great "rust proofing" for cars if it keeps the salt water, generated by melted road snow, from sticking to the underside and rotting out everything. In western PA, "old cars never die they just rust away!". The only antiques around here are constantly washed and garage kept. I've seen 5 yr old trucks with rusted rockers and bedsides. This could be the game changer that Ever Dry was supposed to be.
WarrenHarding
If they can make it stick to porcelain I'd say toilet bowls would be a good application. You could throw away your toilet brush.
Douglas Bennett Rogers
This may be the most important article I have seen on this website!
guzmanchinky
Awesome in so many possible ways! I'd buy a can right now.