A new type of modified wood could have an important place in the architecture of the future. What's special about it? It is transparent and not only transmits light but absorbs and releases heat and is also biodegradable.
A group of researchers from the KTH Royal Institute of Technology in Stockholm, Sweden have been working on the technology for three years. Led by Lars Berglund they managed to create a particular type of transparent material by removing the lignin from the cell walls of balsa wood.
To reduce light scattering, they incorporated acrylic into the porous wooden scaffold. The result was a physically strong material, able to withstand heavy loads but above all with a very interesting feature: transparency, which allowed light to pass through.
But other scientists have further modified the material making it capable of absorbing and retaining heat. Based on the results obtained by their Swedish colleagues, two researchers Montanari and Berglund added a polymer called polyethylene glycol (PEG) to the wood to the transparent wood.
"As early as 2016, we demonstrated that clear wood has excellent thermal insulating properties compared to glass, combined with high optical transmittance," said Céline Montanari recently at the American Chemical Society Spring 2019 National Meeting & Exposition. “In this work, we sought to further reduce the building's energy consumption by incorporating a material that can absorb, store and release heat. We chose PEG for its ability to store heat, but also for its high affinity with wood ”.
The team encapsulated the PEG within a private lignin facility. It also incorporated acrylic into the material to protect it from moisture. Like the previous version, the modified wood was transparent, albeit slightly tinged but also had the advantage of retaining heat.
According to scientists, during a sunny day, the material is able to absorb heat before it reaches the interior space, and the interior will be cooler than the exterior. At night the opposite happens: the PEG becomes solid and releases heat inside, so you can maintain a constant temperature in the house.
The transparent wood thus produced promises to be more environmentally friendly than other building materials such as plastic, concrete and glass. In addition to its thermal storage capabilities, it can also be easier to dispose of. Both PEG and wood are both bio-based and biodegradable. The only part that is not biodegradable is acrylic, but it could be replaced by another bio-based polymer.
A new solution that could help contain the energy consumption that is increasing dramatically in the world. Much of this energy is used to light, heat and cool homes and offices.
The new material could be available as early as the next 5 years. Meanwhile, scientists are working to increase the storage capacity of the material and make it even more energy efficient.
Will it be the building material of the houses of the future?