We're living in a super materials world.
There's a new kind of plastic that can be recycled endlessly. Even cardboard has been re-invented to be stronger and more flexible. And let's not forget the extraordinary potential of graphene, a super material that promises to make everything from cleaner drinking water to invincible condoms.
So it shouldn't come as a surprise that scientists have taken a long, hard look at wood — and found even that stalwart of human civilization could use a little tinkering.
Researchers at the University of Maryland have re-designed the material to make it entirely impervious to visible light, while only absorbing the slightest levels of near-infrared light.
Translation? Rather than absorbing sunlight, the new wood could bounce it right back into the environment. In effect, homes made from this material would be able to prevent virtually all heat from seeping indoors, potentially easing our reliance on air conditioning in summer months.
“When applied to building, this game-changing structural material cools without the input of electricity or water,” noted Yao Zhai, one of the study authors, in a press release.
We know that air conditioning saves lives, especially in climates where heat takes a deadly toll on air quality. But we also know that as we dial up the AC, we also dial up demand on fossil fuel-burning power plants. And emissions from those plants stir up an atmospheric cocktail that can be just as toxic.
"Reducing human reliance on energy-inefficient cooling methods such as air conditioning would have a large impact on the global energy landscape," the researchers note in the study abstract.
To make that kind of "cooling" wood, scientists used hydrogen peroxide to strip away the lignin, a support element in the cell walls of trees. That process exposed only the wood's cellulose, which is a powerful building block of plants and trees. It's also incredibly impervious to the sun's energy.
What's more, the lignin-free wood allows heat produced indoors to escape. That's because indoor heat occupies a slightly different wavelength than your garden variety sunlight — a wavelength that doesn't get repulsed by the new wood variant. So by day, the sun's heat is kept at bay, and at night, indoor heat dissipates into the environment, although the team admits this could be an issue when it comes to actually retaining heat indoors.
Another benefit to wood made entirely of cellulose? It's incredibly strong. In a previous study, researchers noted that cellulose nanofibers outperform steel and spider silk as the "strongest bio-material" on Earth.
The University of Maryland team claims the new wood packs a tensile strength of around 404 megapascals, or more than eight times that of natural wood. That puts it somewhere in the neighborhood of steel.
"Wood has been used for thousands of years and has emerged as an important sustainable building material to potentially replace steel and concrete because of its economic and environmental advantages," the authors note.
That kind of strength, in addition to the insulation factor, could make the new wood a solid candidate for transforming the concrete and steel jungle of a city into something closer to a real jungle.