Researchers at the University of Maryland have developed a transparent wood that is a promising material for applications in buildings with high energy efficiency. The creation was disclosed in an article in Science Advances entitled “Solar-assisted manufacturing of standardized transparent wood on a large scale”.
Transparent wood is not new, but the technique used by these researchers is much simpler and still has energy efficiency.
Wood is made of cellulose, which are tiny fibres, and lignin, which joins these fibres together. Lignin also contains molecules called chromophores, which make wood brown. Instead of trying to remove lignin – using dangerous chemicals – scientists at the University of Maryland found a much simpler and cheaper way, done as follows: scientists took wooden boards one meter long and one millimetre long thick and applied a hydrogen peroxide solution with a regular brush.
When left in the sun or under an ultraviolet lamp for about an hour, the peroxide bleached the brown chromophores, leaving the lignin intact, so that the wood turned white.
Then, they fused the wood with a transparent and resistant epoxy (designed for marine use), which filled the porous spaces of the wood, making it white and transparent. The wood epoxy allows 90% of the visible light to pass through. The result is a piece similar to glass, but with the strength and flexibility of wood.
As a result, this material can replace window glass, as it provides much better thermal insulation – bearing in mind that glass windows are the main source of heat loss or cooling. In addition, transparent wood is much more durable than glass.
In addition to being lighter, the team found that this wood is 50 times more resistant than old-fashioned transparent wood. Therefore, it could be used to cover large buildings. And the researchers say it can also be used for roofs, generating even more energy savings.