Engineers reinforced wood and now it's 12 times stronger than normal wood and 10 times tougher.
How did they do that? Well they started by boiling it in an aqueous mixture of caustic soda and sodium sulfite (NaOH and Na2SO3).
That way they partly removed the wood's lignin (the chemical substance that makes wood rigid) and hemicellulose.
Then they compressed the wood under mild heat, at about 65 degrees Celsius (150 F). Holes, knots or any other defects are crushed together.
On another scale the compression leads to to the total collapse of cell walls and the complete densification of the wood with highly aligned cellulose nanofibres.
The engineers found that if the wood's fibers are pressed together so tightly they form strong hydrogen bonds.
Also the compression makes the wood five times thinner than its original size.
It works for multiple types of wood.
The benefits are clear:
The process isn't that complex or expensive. It results in a cheap, very strong lightweight construction material, with stable features even in humid environments.
The team consists of engineers at the University of Maryland, College Park (UMD) and is led by Liangbing Hu.
They previously made a range of emerging technologies out of nanocellulose related materials:
for instance photonic paper improving solar cell efficiency by 30%, a battery out of wood, and transparent wood for energy efficient buildings.