Feat of clay

Published in New Scientist, 10 Nov 2010

The stuff of pottery and piggy banks can be transformed into a material stronger than steel but as light as plastic. Jon Cartwright reports

Julian Evans leans back on his chair in the chemistry department of University College London. For the past hour or so we have been discussing a new wonder material, and now it’s time for me to see it for myself. He shows me a close-up picture of a sample. It looks like the plastic wrapping on a pack of supermarket fruit. “It’s see-through,” I observe, surprised.

Lots of materials are transparent, of course, but they are rarely noted for their strength. Yet this stuff is stronger than steel, and perhaps even a match for Kevlar, the material used in bulletproof vests. It’s also as light as plastic yet as stiff as carbon fibre.

Perhaps the most surprising thing is that it is made from clay – the same stuff we use to make bricks and crockery and which sticks to your spade as you dig your garden. But treated in the right way, clay’s properties can be transformed. It is also dirt cheap. “All you need is to pull it out of the ground and wash it,” Evans says. […]

The rest of this article is available here.