Stronger than aluminum, a heavily altered wood cools passively

Enlarge / A look at the lignin-free compressed wood. (credit: University of Maryland)

Most of our building practices aren’t especially sustainable. Concrete production is a major source of carbon emissions, and steel production is very resource intensive. Once completed, heating and cooling buildings becomes a major energy sink. There are various ideas on how to handle each of these issues, like variations on concrete’s chemical formula or passive cooling schemes.

But now, a large team of US researchers has found a single solution that appears to manage everything using a sustainable material that both reflects sunlight and radiates away excess heat. The miracle material? Wood. Or a form of wood that’s been treated to remove one of its two main components.

With the grain

Wood is mostly a composite of two polymers. One of these, cellulose, is made by linking sugars together into long chains. That cellulose is mixed with a polymer called lignin, which is not really a single polymer. The precise chemical formula of its starting material can vary among species, and it typically contains multiple places where chemical bonds can form, turning the polymer into a chaotic but extremely robust mesh.