Today, the availability of more sustainable material for construction is only a few. Problems such as the amount of carbon emissions are one of the major concerns. However, researchers in the United States just discovered something remarkable that can make things less complicated. The wood or simply the chemically treated wood can be a material to reflect sunlight and to radiate the excess heat.
Wood like other material is composed of two polymers namely cellulose and lignin. Unlike lignin, cellulose can be easily broken down into simple sugars. Meanwhile, lignin is quite complicated to digest being a problem in biofuel production. However, despite the polymer's difficulty in terms of digestion, lignin is more responsible for the wood's strength.
It may seem peculiar, but in the study, their experiment involved removing the lignin by chemically treating. The process comprises of dumping the wood in concentrated hydrogen peroxide and boiling it. By removing the lignin, theoretically, the wood is expected to lose its strength, however, it became stronger through several tests. So what happened? The removal of lignin resulted in the compression of oxygen/hydrogen groups that hang off sugars which are then free to interact with each other, creating a dense hydrogen bond mesh. From the obtained results, it can be concluded that the treated wood can be an alternative or a new construction material not only intended for the building a house but also in other areas.
Aside from its notable strength, given that the cellulose fiber is roughly aligned along the grain of the wood, it cannot absorb heat. The sugars in cellulose are good infrared radiation emitters, and they do so in two areas of the spectrum where none of the atmospheric gasses is able to reabsorb it. When the treated wood absorbs some heat of structure, it will eventually radiate it back to the atmosphere. This was confirmed by a test wherein a small heater was placed inside a box made of the treated wood and exposing it to sunlight in Arizona, according to Ars Technica.
The radiated heat of the treated wood was measured three times. At the heat of the day, a square meter of it can radiate away 16W of power. At mid-day, if there is no heat source inside the box, its ambient temperature was lower than the surrounding air which is 4°C and at night, it radiates 63W. It only shows that it can efficiently emit more infrared than absorbing it at three visible wavelengths.
To further check its efficiency in terms of using it for buildings, the researchers developed a model of a common apartment building with heat sources, placed it in 16 cities in the US and tracked its energy balance in one year using historical weather data. The researchers discovered that covering a house or building with it can save 35% of the energy used for cooling. Also, in terms with the issue of forestry, researchers assure that the new discovery is manageable and a sustainable one.
