FOR IMMEDIATE RELEASE | January 29, 2009

"Super paper” stronger than cast iron

WASHINGTON, Jan.29, 2009 — In the future, bulletproof vests could be made out of paper. Yes…paper! Scientists in Sweden and Japan have come up with a new material, made from the cellulose in plant cell walls that is stronger than cast iron. This “super paper” also happens to be environmentally-friendly, the researchers say.

Cellulose is the stuff used to make ordinary paper. Scientists have already developed a wide variety of materials out of cellulose, including some plastics. Although existing cellulose-based materials are strong, they tend to be brittle and break easily when under stress.

Now, a team of scientists headed by Lars A. Berglund have figured out a way to make these cellulose materials stronger and tougher. They exposed wood pulp to certain chemicals. The chemicals changed cellulose into a thick

liquid consisting of nanoparticles. Those tiny bits of plant cell wall were each about 1/5000th the width of a single human hair. Then, scientists converted the nanoparticle mixture into a new kind of paper. In laboratory tests, the scientists showed that the ability of the paper to withstand breaking exceeded that of cast iron. That’s the material used to make heavy black frying pans.

Since the paper is as tough as iron, you probably won’t want to turn it into paper airplanes or paper wads for throwing at your friends. On the other hand, “super paper” might one day protect soldiers from bullets. And since scientists obtain the paper from plants, a renewable resource, you’ve got the makings of an environmentally-friendly super-material, as well.

Listen to this episode of Bytesize Science at www.acs.org/BytesizeScience.

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— Mark T. Sampson