With so much focus on glass and steel construction, wood may seem a bit boring right now. But the researchers at the KTH Royal Institute of Technology in Stockholm would disagree.
Not only have they created a sturdy transparent material from timber, but the transparent wood can also store and release heat too. This makes them quite useful in the construction of energy-efficient homes.
Now, here’s the exciting part. To increase its eco-friendly credentials, the researchers intend to develop a biodegradable version of the wood. That way, it can be an effective alternative to glass, plastic or even cement.
In a statement to The Guardian, researcher, Céline Montanari said:
“We prepared a multifunctional material – it can transmit light very well, and also it can store heat. We combined these two functions in a single material.”
Montanari and her colleagues presented their work yesterday at the American Chemical Society (ACS) Spring 2019 National Meeting & Expositing in Orlando.
How the Researchers Created a Transparent Wood
In previous work, the team successfully removed lignin – a component that gives wood its strength and color – from balsa wood.
Building on that work, they introduced Acrylic into the remaining tissues. Aside from filing the pores created by the lignin removal, the non-biodegradable water repellant entered the hollow vessels that transport water in the tree.
According to Montanari, this maintained the wood structure and restored its strength. Also, the tree’s optical properties improved significantly. In the end, they had a frosted-looking wood-based material.
The Heat Absorption and Release Feature
In a recent effort, the researchers pushed the work a little further; they mixed the acrylic with polyethylene glycol. Why this substance, you wonder?
Aside from its ability to permeate wood well, polyethylene glycol also has another interesting feature. When heated, the compound absorbs energy and melts. But as the temperature drops, it hardens and releases energy.
In an energy efficient home, the wood-based material can absorb energy from the sun and release into the interior later at night.
“If you take 100g of this transparent wood material with the [polyethylene glycol] inside, it can absorb up to 8,000J of heat, which corresponds to basically what a 1W [bulb] could produce in two hours.”
As impressive as it all sounds right now, there’s still plenty of work left. This includes scaling up production of the material and using computer models to check how the transparent wood compares with glass.
However, the researchers suggest that the most urgent task is replacing the acrylic with a biodegradable alternative. But that may not be such a good idea.
According to Mark Miodownik, professor of materials and society at University College London, who was not involved in the research, making the material biodegradable would make it less environmentally sustainable.
He further explained that construction materials need to be carbon sinks. As such, they must be recyclable and reusable – like steel is used for modular construction – and not biodegradable.
I am very interested. It should be out it the market the soonest.
Features are impressive.
Is the material not prone to fire?