Posted on 02/20/2008 6:53:56 PM PST by BGHater
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A material that is able to self-repair even when it is sliced in two has been invented by French researchers.
The as-yet-unnamed material - a form of artificial rubber - is made from vegetable oil and a component of urine.
The substance, described in the journal Nature, produces surfaces when cut that retain a strong chemical attraction to each other.
Pieces of the material join together again as if never parted without the need for glue or a special treatment.
This remarkable property comes from careful engineering of the molecules in the material.
The French researchers are already making kilogramme quantities in their Paris laboratories and say the process is almost completely green, and could be completely so with a few adjustments.
'Tiny hands'
The secret of the substance lies in how the molecules are held together.
A piece of normal rubber, says Dr Ludwik Leibler, who headed the research, is actually a single molecule with billion upon billions of smaller units chemically welded together to form a giant tangled network.
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 Children are always breaking their toys. Wouldn't it be nice if you could put them back together so easily?
Ludwik Leibler
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The elasticity comes from the fact that the strands within the network are buckled like a concertina: pull on them and they straighten and elongate; let go and the buckles reappear.
But break a rubber (or most other solids), and the chemical welds - known as covalent bonds - are also broken.
These cannot be remade. Nor can a piece of rubber be remoulded or reshaped.
"We wanted to see if we could make a rubber-like material using small molecules," Dr Leibler of the Industrial Physics and Chemistry Higher Educational Institution (ESPCI) in Paris told the BBC's Science In Action programme.
The trick was to replace the covalent bonds in rubber with weaker connections known as hydrogen bonds.
These are like hands on neighbouring molecules that can clasp together, but let go when broken.
Dr Leibler quickly realised that this meant not only that the new rubber could be recycled and remoulded many times over, but that if separated by a cut or break, the chemical hands at the fresh surfaces would still be waving about ready to bind again.
Child's play
François Tournilhac, who runs Dr Leibler's laboratories, demonstrated the healing to me.
Using a razor blade he severed a thin strand of the yellowish material (the colour of corn oil), showed me the clean square faces, and then pressed them together.
Almost immediately, the grip was strong enough for him to hold the sample just at one end.
Within an hour the bonds had rebuilt themselves so thoroughly that it was possible to stretch the strand to twice its length without any sign of weakness where the cut had been made.
One obvious use, says Dr Leibler, is for self-healing seals.
Puncture a seal in a compression joint with a nail, and the hole would automatically repair itself.
He also has more playful suggestions.
"Why not use it to make children's toys? Children are always breaking their toys. Wouldn't it be nice if you could put them back together so easily?"
The material was developed with the support of the French company Arkema, which is already investigating whether it can be turned into a commercial product.
Now if you could make a prophylactic out of that stuff....
Works good. Smells bad.
I guess pretty soon, nobody will be able to blame the baby on the torn condom.
French velcro. I’ll pass.
That is so funny because it is so true.
Yeah, but just imagine the mess and bother when your kids store 5 or 6 of these balls together in the same bag....
The name is OBVIOUS: Urubber.
Urubber like this and she gets excited.
Urubber like that and she slaps you.
For some wierd reason, this stuff creaps me out.
Maybe clinton would never have been born?
Hokey, hokey, hokey, bs, bs, so faked.
The everlast condom- now guaranteed to outlast your perscription of viagra!
Lol. It keeps going even if you don’t.
Forget that! I was hoping they could make a car tire where you could fix a flat by pissin’ on it. Like the old guy who asked the doc for just half a Viagra. He didn’t care about his sex life - just wanted to stop peein’ on his shoes.
“Works good. Smells bad.”
You wouldn’t notice that if you were french.
Never thought of that ... hmmm. ... you’re right.
Regards
bmflr
Kramer: You know Darren, if you would have told me twenty-five years ago that some day I’d be standing here about to solve the worlds energy problems, I would’ve said you’re crazy… Now let’s push this giant ball of oil out the window.
component of urine = Urea?
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The material in action 