Materials

Getting a grip on ivy's adhesive properties

Getting a grip on ivy's adhesi...
The molecular bonding process that makes ivy so hard to unstick could hold the key to improved medical adhesives and armor
The molecular bonding process that makes ivy so hard to unstick could hold the key to improved medical adhesives and armor
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The molecular bonding process that makes ivy so hard to unstick could hold the key to improved medical adhesives and armor
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The molecular bonding process that makes ivy so hard to unstick could hold the key to improved medical adhesives and armor

Anyone who has tried to clear ivy from the side of their house will know the climber is almost impossible to unstick. A team at Ohio State University has studied the tiny particles giving ivy its vise-like grip, with a view to creating better medical and industrial adhesives, and even stronger armor.

When it's climbing, English ivy secretes minute particles which make the first contact with whatever it's clinging to. These nanoparticles are highly uniform and have a low viscosity, so they're able to work their way into any nooks or crannies in porous surfaces.

The researchers identified that arabinogalactan proteins within the nanoparticles play a key role in the molecular bonding process that follows. As any water evaporates, these proteins interact with pectin and calcium in the liquid oozing from climbing ivy to adhere to the surface.

When it's set, this adhesive is incredibly resistant to temperature changes and different environments, making it capable of surviving natural disasters and determined gardeners alike.

"It's very difficult to tear down, even in a natural disaster. It's one of the strongest adhesive forces in nature," said Mingjun Zhang, the biomedical engineering professor leading the OSU team. "Ivy is very resistant to various environmental conditions, which makes the adhesive a particularly interesting candidate for the development of armor coatings."

That means the bioadhesive could be useful when trying to heal wounds after injuries or surgery, and the US military is also interested in the potential for it to strengthen armor systems. The OSU team's research could also be useful in combatting the impact of ivy on old buildings and bridges, where it can cause significant damage.

"It's a milestone to resolve this mystery," said Zhang. "We now know the secret of this adhesive and the underlying molecular mechanism."

The research is published in Proceedings of the National Academy of Sciences. Funding came from the US Army, the National Science Foundation and the US Department of Energy.

Source: Ohio State University

3 comments
JenniferPage
As ivy has such wonderful grip, surely it should be encouraged on crumbling buildings as a living support system. UK research into this now recommends ivy covered walls have a better survival rate. Its flowers provide early spring food for bees and its berries winter fodder for birds. Encourage ivy to flourish.
Nik
Ivy destroys buildings, by sneaking into cracks and rooting, then with subsequent growth the plant expands, and forces brick, or stonework apart. It also channels rainwater into the cracks, and anyone associated with restoring buildings can testify to the damage that water ingress causes. While they are investigating how to reproduce the 'stickiness' of ivy, it would also be a service to humanity, if they found a way to destroy it, so that the invasive pest could be removed easily. Its shiny evergreen leaves are highly resistant to herbicide sprays. Ivy also kills trees by suffocating them, and strangling them. A tree needs to breathe through its bark, and it needs essential sunlight, which evergreen ivy deprives it of. Ultimately, the ivy can be so thick and strong, that its grip prevents the trees nutrients from flowing, and it kills the tree. I'm presently rebuilding part of the wall of my 150+ year old stone barn, that collapsed due to the 'loving grip' of ivy, and I have a constant battle to prevent it choking my fruit trees. Anyone who suggests introducing ivy to a building, is ignorant of its dangers. If they want to grow the stuff, to feed wildlife, then construct a suitable trellis, well away from buildings and trees, where it can be controlled. Using it for military purposes, is just extending its destructive nature, but that's 'progress' I suppose.
Lewis M. Dickens III
Boo to Nik and yea to Jennifer.
While Restoring the Founder's house of Wayne University I asked Chuck Cares of the University of Michigan school of Landscape Architecture if Ivy really was a problem so we walked over to "Old Main" the Originial building on Campus that was beautifully covered with Ivy. It had an Ivy league look to it. And It dated back to the 1890's.
His first question was where is it oldest? And of course that was down near the ground and so he grabbed the 4" trunk and we pulled back the branches and he then asked is there any damage. The answer was NO.
Ivy does not destroy buildings. You cannot use a categorical answer.
So an Engineer got the job of putting on an addition (he thinks that he's an architect) NOT. And so he tore all of the 100 years of ivy off of the building. It now looks terrible. But thanks to Michigan's Landscape Program the Michigan Union where JFK gave the Peace Corps Speech is now flourishing with a beautiful layer of Ivy. So the answer is Go Blue and use Marry Potter Ivy if you can stand red.
Bill