Household insulation comes in many forms. Asbestos was once a cheap wonder-material until it was deemed carcinogenic. Cotton candy-like fiberglass wool is common, but deceptively hazardous, laced with tiny fiberglass shards that can penetrate lungs. And while expandable Styrofoam films aren’t entirely detrimental to our health, they don’t decompose—posing chronic environmental problems down the road.
What we need is an insulation alternative that is effective, non-hazardous, and environmentally friendly. A new material called nanowood seems to fit the bill.
Although its name sounds futuristic, nanowood is completely derived from trees. It is exceedingly flexible, lightweight, and—unlike other insulators—totally sustainable. Because it’s made from trees, it can be commercially produced to fit any shape sculpted from wood. Like paper, thin slices of nanowood can be rolled up without breaking. Moreover, nanowood has super-thermal insulating capacity on par with Styrofoam, making it suitable for applications requiring tightly regulated heat transfer— like energy-efficient buildings, electrical devices, and aerospace applications.
To generate this new material, scientists at the University of Maryland used techniques very similar to the techniques used in developing this innovative spinach leaf heart . Sheets of wood were cut along a tree’s plane of growth and treated with reagents that removed cells and stripped away most wood components. The scientists were left with many parallel sheets of plant-sugar scaffold (or nanocellulose), which not only reflect heat, but also dissipate any trace amounts of heat that do manage to penetrate. By combining reflection with deflection, nanowood has low emissivity, which gives it an advantage over Styrofoam in blocking the sun’s thermal radiation. This makes the earth-origin material suitable for applications in outer space.
Since carbon dioxide is the main ingredient of plant sugar, and by extension, decellularized nanowood, this non-toxic, flexible, super-insulating material may seem too good to be true—and with estimated costs of manufacturing at $2.27 per square foot, this dream-product could be market-ready in no time.
Photo credit: Hua Xie / University of Maryland